 the National Center. But what I'm truly excited about this evening is having the pleasure of welcoming all of you as well as many more guests I hope who are joining us live on a webcast to our beautiful Mesa lab here in Boulder to the inaugural event of our new Explorer series. The National Center for Atmospheric Research which is simply known as NCAR was established in 1960 and has been and remains today a world-leading research institution and truly a national resource dedicated to the study of the atmosphere, the earth system, and the Sun. The work that we do here is incredibly relevant to all of you because of the fact that our daily lives are touched by weather, air quality, and climate events and sometimes unfortunately these events can be catastrophic in nature such as severe weather outbreaks, flooding, and droughts by the ever-increasing impacts of a warming planet and by disturbances emanating from the Sun that can have impacts such as disrupting satellite based navigation systems. And because our sponsor the National Science Foundation is a federally funded agency we can only carry out this research and we can only translate the results of this impact to the benefit of society because of you because of the tax-paying public. So I work for you. That is actually a truly motivating idea behind this new Explorer series and that is to augment the ways in which we try to reach out to the public, ways in which we try to inform the public and hopefully excite, inspire, and educate the public by inviting you to come to events such as this tonight to engage in a conversation with researchers at the leading edge of their field who are motivated by the work that they do and very much want to communicate the importance of their scientific discoveries and what that means to you. So these evening discussions such as tonight are free to the public. Thank you very much for coming to this very first event. We're going to learn about how this works together and try to take lessons and improve future presentations. I do want to note at the outset here that over the course of this year we will have three additional presentations covering topics from in-car research and technology and aviation weather which is critical to all of us the fly to keep us safe in the skies. To the upcoming solar eclipse that we'll all witness in the year 2017, including how you can get involved as citizen science, citizen scientist in the science that we want to pursue with this eclipse. To a description of the health of the world's coral reef systems and the threat that human induced climate change poses to these very important natural marine ecosystems and resources. But first tonight we're going to talk about a phenomenon that is very much in the current news and that of course is El Nino. What is El Nino? How frequently does it occur? How does it impact the weather here in Colorado? How does it impact the weather across the United States? And how is El Nino and climate change likely working together to make weather headlines across many parts of the world? Those are all topics that we'll hear about tonight. And to lead this conversation it is a great pleasure to welcome and introduce a longtime colleague of mine at in-car, a terrific personal friend to both me and my family, and that is Dr. Kevin Tremberth. Kevin is very highly honored and distinguished senior scientist at in-car. He comes from New Zealand. He received his doctorate in atmospheric sciences from MIT in 1972. Kevin has been very prominent in many different aspects of climate variability and climate change research. He's published more than 500 scientific articles and 60 books and book chapters over his career. Placing Kevin is one of the highest-sided authors in all of the geosciences. Kevin has also served many very important national as well as international science planning committees including extensive service to the world climate research program and lead roles in the scientific assessments of the intergovernmental panel on climate change. For his leadership and scientific contributions Kevin has received many awards and honors and he is a fellow of the American Meteorological Society, the American Association for the Advancement of Science, the American Geophysical Union, and he is an honorary fellow of the Royal Society of New Zealand. Kevin is also very passionate about communicating the science that we do here, the science that he is personally engaged in. He reaches out to the public in countless ways including many many interviews on television, on radio, in newspapers and in magazines and for those of you that were home this evening at five o'clock on channel seven you might have seen Kevin give an interview in that broadcast. So he's had a busy day. Indeed for his efforts in promoting scientific literacy Kevin received the very prestigious climate communication prize from the American Geophysical Union in 2013. So thank you all so very much for coming this evening. I hope that you come to future events. I hope you enjoy the ability to tour around the Mesa Lab and importantly right now please join me in welcoming Dr. Kevin E. Trimberth to the stage. I do want to mention that after Kevin's presentation we will have ample time for questions and answers including those of you on the live webcast that want to submit questions. So please hold off on questions until after the presentation. So Kevin. Thank you very much Jim. I think this microphone is working. I want to thank Jim especially and NCAR for putting on the series. It's something that's unique in the 50 years that NCAR has been around. And I also especially want to single out one person. Yaga Rikta who's down here who was the initiated the series and has been a primary driver behind it. So I hope that you will get your good value out of this. The the price price of admission and we'll be able to fill in the little questionnaire that you've been given and thinking think about paying it forward in perhaps some fashion and tell other people about NCAR. So the topic I'm due to discuss this evening is the topic of El Nino. There's a picture here from July of 2015 of the sea surface temperature anomalies in in the tropical Pacific which is where the El Nino phenomenon is based. When I graduated with my undergraduate degree in New Zealand I went to work for the New Zealand Meteorological Service and I became a junior weather forecaster where I was actually working shift work for a period of time. I was also a rugby player. I played senior top level rugby. You may know something about the all blacks. I wasn't quite at that level but I nonetheless played against all blacks and as a result we were subject very much to the foibles of the weather from week to week and so with my job and with this activity I was very much aware of the weather and I noticed some patterns of weather from especially one year to the next in the brief time before I went to do my PhD at MIT and then after I got back from MIT I looked into this in further detail and found that indeed the patterns were very much related to this thing called the Southern Oscillation which is very much related to the El Nino phenomenon and so I wrote papers about this in 1975 and 1976. It's a long time ago now. That tells you a little bit about maybe how old I am. But Jim told you when I got my my PhD anyway. But anyway that's my background. It means I've been actually looking into El Nino phenomena longer than most other scientists and long before El Nino even became a common phrase among scientists. So with that I will begin and talk about the El Nino and so we don't actually have any Ninos in the in the audience. Young boys at least and this one says El Nino is back. So what is El Nino and what does it do for us? This is a picture, a satellite picture from January 14th last week showing the main storms out in the Pacific and also let's see if this works coming across from California and heading for for Colorado. And indeed if you've been watching the weather you'll see that there's been a stream of these storms coming through here headed for Colorado and they have an El Nino aspect to them. So this is a few days later. This is just two days ago I marked Denver on here so you can see where where we actually are. So one little storm went went through here broken up a little bit by the mountains and the next one is coming was coming into California and indeed there was another one downstream and there's another one approaching California as well. So there's a stream of this this onslaught of storms which are controlled to some extent by this El Nino phenomenon and they've been dumping quite a bit of snow in the mountains. Now this is not normally a characteristic that we see with the El Nino phenomenon. Most most commonly the in El Nino years the storms tend to track somewhat south of Colorado so southern Colorado may get more snow but the northern Colorado often has less snow and this year northern Colorado is about normal but southern Colorado is about 10 percent above normal in terms of the overall snowpack. So that's something unique to this particular El Nino and it turns out that in Colorado there's not a strong El Nino signature but what I'm going to do in this talk is to tell you how these the weather patterns set up and affect the United States and to some extent Colorado and I hope I can answer any questions that you have in that regard later on. So to begin with you know what is El Nino and what is this thing called Enso? If you look up if you google Enso you will find that there's some major Wikipedia results for that and and I'll say what Enso is in just a second but El Nino really refers to the warming of the sea surface in the central and eastern tropical Pacific. It really is the ocean part of this thing called Enso and Enso stands for El Nino Southern Oscillation and so the Southern Oscillation is the atmospheric part. It's really a global wave pattern and I'll show you exactly what that refers to a little bit later. Now these two phenomena were discovered completely independently and maybe around about the same time. The word El Nino grew up from fishermen along the coast of Peru and Ecuador and they noticed that there was this warm current that came down from the north along the coast of Peru around about Christmas time and that got rid of the fish that they were after and so they worried about this and then they noticed that about every three or five years this warm current was more extensive and lasted longer and so the term El Nino was originally applied to this annual current that occurred around Christmas time and the El Nino refers to the Christ child and then it took on this name for the unusual events that occurred and it lasted that way for quite a long time. In the meantime Sir Gilbert Walker was appointed the head of the Indian Weather Service in 1904 and he was trying to find out why the Indian monsoon failed from one year to the next and he discovered this phenomenon called the Southern Oscillation and it turns out this is a very large-scale pattern and it does have some influence on the on the monsoon and he was able to document this in a series of papers going through into the early 1930s in actual fact but it wasn't until 1969 when Jacob Bjorkness was able to link these two together and it turns out that the coastal phenomenon of El Nino has a whole basin scale signature and is very much related to the Southern Oscillation and so the term Enso is what scientists call the overall phenomenon and it relates to actually both phases of the El Nino phenomenon and the other phase the cold phase was actually christened in 1974 very much later as sort of the opposite of El Nino La Nina which is really the girl in Spanish so I don't know whether it's really the opposite but that's what it is and it refers to cooler than normal sea surface temperatures in the tropical Pacific. These El Nino events occur about every three to seven years they're not unusual and we are in either an El Nino event or La Nina event about half the time so I will show you exactly what's happened in that regard just a little bit later but in the tropics these kind of fluctuations from one to the other are not uncommon so the peak El Nino tends to occur around about the Christmas time and that's where the name comes from the Christ child the boy the little one and the contrast is with the La Nina the girl. It has very profound effects as I mentioned before on fish it it changes the nutrients within the ocean because it changes the currents that occur in the ocean the the upwelling currents in particular that bring the nutrients up to the surface where they can interact with the sunlight and various organisms can grow and then of course the fish feed the seabirds and and other mammals coastal mammals otters and seals and things like that and ultimately the people are affected through the overall food web and so it does actually have profound effects which have grown over time especially after about 1972. 1972 was when there was a El Nino event that caused a major failure of of the fishery and a loss of anchovy which was being used for chicken food in the United States as an example so and so the two the two things together the atmosphere and the ocean is really a natural mode of the coupled ocean atmosphere system and the term relates to the atmosphere in the ocean working together these events have actually been going on for centuries maybe even millennia and we can determine that from records in in corals in the ocean in the tropical pacific and in things like ice layers and there's an example here from the calcaya ice cap in Peru and this is a really good example maybe you can see that the ice layers tend to vary a little bit from from one year to the next and in fact you can find a record of El Ninos in in this in the ice cores from this from this glacier the the the Enso phenomenon is is fairly unique it arises not as an atmospheric phenomenon or as an oceanic phenomenon but as the combination and the interaction between both and I'm going to try to describe that to you and we'll see how successful I am a little bit later so I'm firstly I'm going to try and give you some of the setting for this what happens on average especially in the tropical pacific and so here's the setting with regard to sea surface temperatures and so maybe you can see here this is January on the left the warmest water is down here extending down towards the north of Australia and of course this is the summer in the southern hemisphere and then in July the warmest water is up around southeast Asia and the warmest water in the world tends to be in the tropical west and pacific there are very much reasons for that it relates to the size of the pacific and the fact that in the in the tropics there are easterly trade winds and so the trade winds are blowing from the from the east to the west and piling the warm warm warm water up and skimming warm water off of the surface and carrying it over into this region of the ocean and at the same time the seasons are migrating the warm water back and forwards across the equator now these numbers are in degrees Celsius and down here i put a scale for you and so the the these high temperatures are up around about 83 84 degrees and and these are plenty warm enough to sustain a hurricanes or on that part of the world they're called typhoons so what i'm now going to do is show you whether main rainfall occurs in these regions so here's the strongest rainfall these are all where this there's a scale down here in millimeters per day so this is four and a half millimeters per day but never mind this is where the heaviest rains occur in the world and so this is the monsoon in south africa south america this is the monsoon in in in south africa and and this is in in in the monsoon in northern australia and so the rains are into the southern hemisphere and very active down through here and then in july the rains are also over the warm water and over southeast asia and this is the asian monsoon that is occurring at this time and in south america the the rains have moved up into the northern part and into central america and even into mexico and so let me jog back and forwards here whoops uh go the other way so we can see where the sea surface temperatures are and the rains and this is very important because if we then change the sea surface temperatures which is what happens during el nino events the rains in turn tend to follow and change as well and when the rains change that affects also the heating patterns of the atmosphere which has consequences it turns out all around the world so the part of the lesson here is that the high sea surface temperatures sort of determine where the main action is in terms of especially thunderstorms and tropical storms all of the rain that is occurring and the low sea surface temperatures tend to determine where the action isn't the low sea surface temperatures tend to be where there's large anti cyclones large high pressure systems and relatively fine weather here's a picture now of the precipitation and what i'm going to do is click on this little link here and go through the annual cycle and so here it is we're starting in the top left up here is the calendar and you can actually see the migration of these rains going across the equator with the monsoons where the land is occurring but there's almost no migration out here in the central and eastern pacific and actually that's a key part of the phenomenon because it partly enables the el nino phenomenon to occur this region here is called the inter tropical convergence zone and it is called that because that's where the trade winds from the two hemispheres come together so there's the northeast trades and the southeast trades come together in this region and uh and they're uh this is a little bit like the monsoon circulations except this is occurring over the over the oceans so there's a famous poem with many many verses and this is just an excerpt from it from from samuel taylor colleridge uh the rhyme of the ancient mariner and i'm going to read this because it it's all about what's going on with the weather in this particular neck of the woods the fair breeze blew the white foam flew the furrow followed free and we were the first that ever burst into that silent sea so let me activate here on the right this is where the trade winds are very very steady trade winds and of course this is a time when they were sailing but then down dropped the breeze the sails dropped down towards sadder sad could be and we did speak only to break the silence of the sea and so they're in the region that that time was called the doldrums now we call it the itcz the inter tropical convergence zone all in a hot hot and copper sky the bloody sun at noon right up above the masted stand no bigger than the moon so think about that for a second the bloody sun at noon was right up above the mast and so they're right in the vicinity of the equator and the hot and copper sky means that the air is just full of moisture there's a tremendous amount of moisture as occurs in these regions and then day after day day after day we stuck nor breath nor motion as idle as a painted ship upon the paint a painted ocean and so they were in this region between the trade winds where there was essentially no wind for them to to go out of it and of course they're in a sailing ship but this I hope this will give you some meaning because this is where the the El Nino phenomenon has its origins and it's very much related to these phenomena so this is a map now of the southern oscillation and you can see perhaps that it has one core which is here in the western tropical pacific and and in this case centered not far from Darwin which is in northern Australia but it has connections all the way across into Africa and all the way around into the Atlantic and across into even north the northeast part of Brazil and then on the opposite sign is this large connected region in the eastern side of the pacific extending well into the north into the into the extra tropics and down south of New Zealand and so this is remarkable it's a it's a global scale pattern and what happens is that we get high pressure here under El Nino conditions and low pressure here so this means this is where all the rain is occurring and there's high pressure droughts and dry conditions here but it extends across into Africa and across into the northeast part of Brazil and meanwhile there's all kinds of activity going on out here and in La Nina conditions this is where the high pressure exists out here and then there's low pressure over here and that's when there are a lot of rains in maybe even in the desert in Australia and over here more active southeast asian monsoons and so on and so tracking this this pattern has been able to account for a lot of what happens from one year to the next in terms of the weather patterns now there's Darwin and in the in the southeast pacific there's Tahiti you'll notice they're very close to the centers of action of this pattern called the southern oscillation and so one way we keep track of this is simply by tracking what's going on with the Darwin sea level pressure and the Tahiti sea level pressure and we take the difference between them and form an index called the southern oscillation index and actually this map is a map that corresponds to the southern oscillation index now another key part of the setting is what goes on in the ocean so here we're going look at the bottom here from indonesia on the western side of the pacific and we're on the equator going across the date line to south america on the eastern side over here and this is the vertical structure within the ocean so this is going down 100 meters 200 meters 300 meters 500 meters and the bottom of the ocean is somewhere around 4000 to 5000 meters down now you can see that there are big differences between the western tropical pacific and the eastern tropical pacific there is quite a striking temperature gradient here a temperature contrast between the warm what is often referred to as the mixed layer that's connected to the surface so this is where the warm water has all been piled up and so let me introduce here the the term the thermocline this is the region in the ocean called the thermocline which really means temperature gradient temperature contrast and it's the region between the region of the ocean which is connected to the surface and the deep ocean which is very cold and doesn't change very much down below the thermocline but the thermocline comes up and is very close to the surface in the eastern pacific so the temperature gradients are very close to the surface here but there's a very very deep warm layer in the western pacific which goes down about 150 meters and so this plays a key role in in this overall phenomenon and here's where the trade winds are occurring and so they're blowing in this direction and so they're skimming off the warm water and piling it up over here and as a result sea level over this side of the pacific is about 40 inches higher than sea level is over here and it's it's held up in that region in the western pacific by the fact that the winds are always blowing in that direction and as a result these winds also skim off the warm water and pile it up over here so there's a deep pull of warm water here now this pattern could continue and this could get warmer and warmer and warmer over in the western pacific this is the warmest part of the global ocean but at some point the system says i can't stand all of this warm water there's too much i'm going to have an El Nino event and so it takes this takes this warm water and sloshes it around and moves it across to the other side of the ocean and it completely changes with it all of the winds and the uh and the rainfall in the atmosphere associated with that and so that's now what we're going to talk about so a key part of this then is that we have sea surface temperatures at the top here let me activate this there's the sea surface temperatures ssts we we refer to them so they're a key part of this thing they very much affect the precipitation the rainfall in the tropics and that in turn affects the surface winds and and vice versa for that matter and the surface winds are connected to the global atmospheric circulation including what happens to the weather patterns across north america and then the surface winds are further connected to the ocean currents this is a little schematic here of the main ocean currents that occur around the world and the ocean currents then change the sea surface temperatures and so there's this feedback this circle that goes around and when there's an El Nino event it turns out they all affect one another in a way that tends to reinforce the original changes and that's what gives rise to this El Nino event and so the El Nino event itself lasts for about a year to 18 months before it runs out of all of this warm water that's been piled up in the western tropical pacific so here's a more complete schematic now of the sort of normal conditions here in the western tropical pacific we have this warm pool of water there's a lot of rainfall thunderstorms tropical storms that go on over in this region australia is here in southeast asia is up over here there's this very deep thermocline here with the warm water extending well below the surface there are trade winds indicated by these arrows here that are blowing in this direction and causing upwelling to occur pulling cold water up from below along the equator in particular and then given that that's happening the winds have to go somewhere the winds are going up in these thunderstorms and then there is this loop where the the air is subsiding in the eastern pacific coming down and creating anticyclones in that region fine settled weather in this region here and this loop now is actually called the walker circulation after sir gullbert walker so that's sort of the average conditions in the tropics to the extent that the average is meaningful and then this is what happens during an el nino event so the warm water sloshes across here because the winds weaken or the warm water sloshes across and causes the winds to weaken because these two things are very much interactive with one another the thermocline the warm water has gone from the western pacific and so the thermocline is much shallower here but the thermocline goes down in the eastern pacific so there's a lot more warm water on the eastern side of the pacific and the thermocline has gone down the action in the atmosphere has shifted into the central pacific and the walker circulation has reversed in the in the western pacific and and maybe it's there's still some remnant of it in the eastern pacific so this is the picture that happens with el nino events but there's more there are all these these things that the the scientists call tally connections so this is just a different schematic of some of the interactions and the things that are going on the interactions between the surface winds the ocean currents the warm pool the tremendous amount of evaporation that goes into precipitation in these tropical rains but then these tropical rains cause heating in the atmosphere because the heat that went into evaporating the moisture in the first place is given back to the atmosphere and that then heats the atmosphere so the atmosphere tends to rise and it has to adjust to that and it causes things called tally connections and i'm going to try to show you how that works a little bit so one example maybe not a perfect analog but this is some sort of an example is the sort of thing that happens with the flow of wind the wind is arrow is given given down here and this happens to be in the caribbean and this is guadalupe island and the wind is flowing past it and you can see it's set up a series of waves fascinating waves quite some distance much much greater than the the size of the island itself downstream from there and in some sense this is what happens with el nino events except instead of a rock in the in the stream it's this large amount of heating that occurs in the atmosphere associated with all of these storms that acts a little bit like a rock in a stream and it creates waves downstream and i'm going to show you an example of that or try to show you an example of that before i do that this is sort of the summary of of what actually happens with el nino events and it turns out that el nino events and la nino events are the main cause of droughts and and very wet regions and potentially floods around the world so during el nino there's a there's a list here of you know where droughts tend to occur and there's a schematic picture here in december january february you can see it's very dry over in the west and pacific dry in australia and southeast asia and also quite warm over here it's also very dry in parts of parts of africa and then later on it can get wet this is it's sort of at the tail end and it can also dry in the northeast part of brazil and at the same time it's very wet out here and in peru and ecuador and also tends to be wet in the southern parts of the united states and and can be quite warm up into the northern plains of west northwest of canada and up into alaska in june july august the action is much more focused in the southern hemisphere and again it tends to be very dry over in the in the australian region and so there are these big effects not just in the tropics but in other places around the world so how does that happen well i'm going to try to illustrate it by looking at a particular case it just so happens this is the one where i where i have a little movie that i developed in association with nhk television in in japan and this relates to the drought that occurred in california along the west coast prior to actually in in 2013 14 more than anything so in the winter of 2013 14 this is where's my where's my thing here there it is so here's the the picture in california very very strong drought but out in the tropical pacific in december january february there was very intense rains out here in fact this was the beginning of the el nino in some sense and the rains here were averaging over 10 inches a month above normal and normally there's quite a lot of rains out here there was just a tremendous amount of rains going on here and quite a dry zone in here and so around the world this is where the strongest heating patterns in the atmosphere were occurring and what that did was to set up some waves that are illustrated here and the first thing that it does is that when you have all of these rains the air comes in at low levels and then it rises and then spirals out at the top and and it forms this anti cyclone in the northern hemisphere which is sort of indicated here and once that forms it starts to affect the jet stream and the wave patterns and you can see this downstream and what i'm going to show you now actually it set up this thing called the ridiculously resilient ridge along the west coast which is responsible for the drought and during this time it also set up this very very cold winter in the in the central and eastern parts of the united states if you remember back one winter and so uh and so it had its origins back in the tropical pacific so here's the movie they didn't quite get it right they didn't put the the the anti cyclonic startup of this in quite the right spot but it gives you the idea anyway and so here's the jet stream and the high and low pressure systems that are normally migrating along in the northern hemisphere i haven't got the southern hemisphere shown here and here's all of this here's all of this heating that's occurring in this region here and as the air flows out it starts to feel the rotation of the earth and so it spins up this anti cyclonic circulation and then gradually that has an influence further north and it starts to set up this low pressure system here and that spins up a low pressure system and then it spins up this ridge further downstream this is what the yellow is really indicating the consequences and then it spins up another low pressure system and so there's this wave that occurs downstream for thousands of miles more it can in fact go all the way around the world and it takes about five days to a week for this to set up once once this thing really gets strong with really strong heating in the atmosphere this whole thing sets up in on the time scale of about a week something like that so this is how teleconnections occur and this is how something that's going on on the tropical west and pacific can affect the ridge the the drought in in california and even the very cold conditions in the eastern part of the pacific the eastern part of north america so this is what happens in the northern hemisphere in winter the the activity has moved out into the central pacific here it pulls the jet stream down and it tends to pull it down into perhaps southern california uh at the moment there's one little branch that's going down into mexico and there's another branch which is sort of going into northern uh colorado at the moment but it brings a lot more weather more directly uh into the united states and and across into potentially into colorado so what about the timing and the frequency of these things and how long do they last well the el nino events tend to peak around december which goes along with the name that it occurs around christmas time but the that's really true for the sea surface temperature anomalies and the anomalies refer to departures from normal here but the peak anomalies the peak unusual aspects of the weather are often delayed somewhat into january and february and even into march and so we still have some of that to look forward to and then also in the latter stages of of the el nino there is a mini global warming because there was heat coming out of the ocean into the atmosphere and as a result the overall temperatures warm up in the atmosphere and some of that's already happening so this is the actual pattern of el nino events and la nino events since 1950 and you can see that in fact here's the zero line here uh this actually refers to a region of the tropical pacific near the equator it's actually from five degrees north to five degrees south over a whole great big chunk of the pacific in the middle i'll show you where it is on a on a later slide but you can see that it it's almost never normal there's some periods in here where it wanders around zero for a little bit but for the most part the weather in the tropics is going from an el nino event to a la nino event then to an el nino event to a la nino event and so on and these things can be as short as two years apart sometimes they're a bit longer and there are three major events on here that get into the very strong category so the category is once it gets to this index in the tropical pacific gets above about one degree fahrenheit this is actually 0.5 degrees celsius we call it a weak event then once when once it goes beyond one degree celsius it's a moderate event then strong and then very strong and there have been three events that are in the very strong category one was 1982-83 one was 97-98 and one was is this year 2015-16 and the latest value for this index is actually at 2.3 which puts it at the same level as the 97-98 event on the la la nino side you can see that often they last a bit longer but they don't have the same degree of extreme in the other direction and so there's a little bit of asymmetry between these two things but my summary of this el ninos are red la ninos are blue they follow in sequence every year or two and here's a cartoon which illustrates this that indeed it's like a roller coaster in the tropics you're you're going from one extreme to the other and it depends where you are whether you're in rain or you're in drought but this is the nature of the weather in the tropics there's not a strong there's not strong seasons in the tropics there is is in the monsoon regions we have a wet season and a dry season but the main source of variability in the tropics is actually the El Nino phenomenon and and this is a good depiction of a lot of aspects of it so one of our challenges here at NCAR is to model this and to simulate it and to understand it in all of its detail in the tropical pacific this is the region that I was referring to as the region that makes up that El Nino index and if we simply do correlations the and establish the relationships in terms of the sea surface temperatures around the world when it's very warm in that region it tends to be warm all through this region and tends to be cold over in the western pacific tends to be warm in the indian ocean and it gets warm in the atlantic ocean in the subtropics uh although these these are a little bit more in the later stages of the El Nino so this is the observations here at the top and this is what happens in uh one version of our climate model here at NCAR and you can see a lot of this is actually quite good but there's some errors over here especially in the western tropical pacific and in the in parts of the indian ocean and so this is something that we're trying to improve in the NCAR models and there's been some quite good progress over time but maybe we're not completely there yet at this point and one of the troubles we we do know is that it's very sensitive to very small scale structures which we have great difficulty including in the global climate models that we run here at NCAR so now I'm going to talk about the 2015 event this is a movie that was put together by Matt Reem at NCAR showing the 1997 event and the 2005 event as we're going through the year you can see the calendar there showing the warming initially the warming has been quite a bit more in the in the north pacific in particular in the 2015 event and it's very comparable in terms of the overall magnitude quite striking overall you would say that these are actually quite similar to each other in many respects but here we are at the end of the year in 2015 and you can see here's the warm water it's maybe not quite as warm as this part here but it's quite a bit warmer out here and it turns out that's one of the key differences between these two events the fact that it's cooler out here means the contrast is greater between the eastern and western pacific and that means that the reversal of the trade winds is stronger in the 1997 event than it is in the 2015 event and so the 2015 event is not producing quite the same weather patterns as a result of that so this is what the actual sea surface temperature departures from normal the anomalies look like from the 8th of November to the through to the 5th of December and this is actually the the peak of this current event and these are in degrees Celsius so here's three degrees here or this is three and a half degrees actually right here so three and a half degrees Celsius is 6.3 degrees Fahrenheit and so this is four degrees Celsius this little little thing in here very very warm unusually warm water mostly the kinds of departures from normal that we see in the ocean in the extra tropics very seldom gets above one degree Celsius so these this is an outstanding event from the standpoint of the overall climate system so the peak was around about the month of November and I'll show you that in just a minute this is backing off now this is the same nearly the same thing this is actually the month of December looking at the sea surface temperatures but now we're looking at it globally we're not just looking at the tropical pacific and you can see yes it's very warm here but we don't have a very cold region over here that you may recall I showed you before it's often accompanying El Nino events it's warm over in the tropical Indian Ocean already and it's quite warm in parts of the Atlantic already and it's exceptionally warm in parts of the extra tropics of the northern hemisphere and this is not characteristic of El Nino events this is unique to this particular event I wanted to show this though so that I could also show you the corresponding sea level anomaly this is sea surface height is what it refers to and one of the amazing things that we have are instruments on satellites that are altimeters that are looking down and measuring the global ocean to millimeter accuracy the latest in the series of these called Jason three was just launched two days ago and that was the rocket you probably saw on the news that didn't quite manage to to stay up but that launched this latest satellite with an altimeter on it that can continue to make these wonderful measurements of the sea surface height and so in terms of sea surface height you can see let me let me activate this and say that this is around about eight inches above average here in the central and eastern pacific in association with the El Nino and also this eight inches above normal extends along the coast of the Americas up into southern california well a year ago these values here were about four inches below normal and so the sea level has actually gone up by about a foot in the central and eastern pacific remember what I said earlier that across the pacific under normal conditions the sea level is higher by about 40 inches over here than it is over here and so during El Nino events a lot of the water has sloshed over in this direction and now sea level has gone up by about eight inches over here but of course that water had to come from somewhere and it's fallen over here it's fallen by about five inches below normal here but before this event occurred around the philippines it was about a foot above average that was what it was in november of 2013 when the super typhoon high end went through and that's why the damage was so great because the sea level was so much higher because all of the trade winds had piled up all this warm water that is now participating in the sel nino event in the philippines and so the sea level has dropped over here and it's risen there and in 1997 98 in early about january 1998 along the coast of california sea level actually got about a foot above average so when sea level is that high and you have storms and waves and winds on top of it there's a tremendous amount of coastal erosion and that certainly happened in 1998 and there's a potential for that to happen along the west coast there's been a little bit of that's happening already in washington and oregon so far this year now what i'm showing you is a is a brief sequence it's animated going from late september through into mid december and so this is the development of the sea surface temperature anomalies down below and this is what is used to characterize this as an el nino event but i also wanted to show you the total sea surface temperature field so this is where we add back on the climatology because it turns out you cannot account for what's going on simply by looking at this you have to also look at the total sea surface temperature field and you can see the warmest water is sort of hanging around out here between 150 west and the dateline out here so this is new zealand is down below here and so this is where the warmest water is actually residing so this has some consequences as it as it turns out that i want i want to show you now because remember what i said when we went through the rhyme of the ancient mariner it's um it relates to where the warmest water is is where the action is it's not where the warmest anomalies are it's where the warmest water is and so that matters this is the sea surface temperature anomaly sequence these are averages along the equator from five degrees north to five degrees south uh over time from january of 2015 time is running in this direction through to december of 2015 and you can see even in january it was relatively warm out here but just by one degree celsius and then as time went on this warming built but also there was warming that developed along the west coast of south america and that built as well and so this is the traditional el nino region off the coast of peru and ecuador where this is occurring and this was occurring already in june of 2015 and then both of these sort of came together and built and the maximum are occurring here is occurring here in november of 2015 and then by the by the time we get to december things have cooled off a little bit already so maybe this event has gone past its peak that remains to be seen whether there's another surge or not so let's look also below the surface i showed you before what this looks like here's indonesia over here here's south america here this is the little mark showing the date line and this is what it looked like below the surface of the tropical ocean in the 18th of january it was generally warm here but a lot of the warm water was to the north and to the south off the equator and it was a little bit cool over here on the eastern side of the pacific not a lot to write home about but by the fourth of march we can see that the warm water is is now come into the trope into the equatorial region and it's pushing down the thermocline and starting to move across the pacific and then by the may it's moved further across and the thermocline is getting shallower in the western pacific and it gets shallower and shallower still and then this warm water has become more and more intense until by the 29th of november it's very near the surface and this is near the peak phase of the sea surface temperatures but you can see that there's this cold water relatively coming in behind it and this is what actually accounts for the demise of the El Nino phenomenon and uh and so when this gets here when this gets to the eastern pacific the El Nino is over and done with so this is through november and then this is a little animation looking at from the beginning of november uh up until uh the third of january showing what is actually happening here and you can see this warm water here whoa it's it's being depleted it's actually quite a lot less at the moment than it was uh in november so again this is an indication along with the sea surface temperatures that the El Nino may have gone past its peak and instead this cold water is is coming across and the and the thermocline is beginning to uh become shallower again so here's the sea surface temperatures now i'm looking at a 90 day period from late september uh into into late december through the peak of this El Nino event so this is where the warmest water was overall but the generally this warm water all through here and and up here uh into central american region this is the corresponding precipitation anomalies and you can see that the strongest precipitation anomalies are out near the dateline actually between the dateline and and about 160 degrees west they're sort of over this region here and so they correspond more to where this warmest water is rather than the eastern pacific there is some in the eastern pacific that that certainly matters out here and these numbers are quite large these are tremendous rainfalls if you are under them and then there's very dry region back in here and so there's major drought in indonesia and there's been some big consequences of that and then what i've also shown you down the bottom here are the winds at the jet stream level in the in the upper troposphere at around 40 000 feet also referred to as the 200 hectopascal level and if you just stand back and look at this you would say well all of the big numbers in terms of the departures from normal are in the eastern hemisphere here over here so we can we can sort of highlight oops we can highlight where the main action is here but let me go back just a second because remember what i said before that when you have something like this in heavy rains that it tends to spin up an anti cyclone in each hemisphere actually in both northern hemisphere and in the southern hemisphere and so here we've got it this is the anti cyclone here's the anti cyclone in the northern hemisphere here's the anti cyclone in the southern hemisphere and so this has made a big difference to where the jet stream is over north america and also across the southern hemisphere into south america there's one branch that goes north there's one bit that goes down right into central america and so this has some big consequences then and in fact this is what led to the major flooding in missouri uh in in december in association with this and so so this is where the action is where the tally connections are in association with this particular event but there's other things going on what about global warming there's climate change occurring and so we can ask these kinds of questions and then this is up to date today the 2015 values for the for the global mean surface temperature were released and they're on this figure here showing that 2015 is by far the warmest year on record the climate is indeed warming and i've also got on here the pre-industrial value the zero line on here corresponds to the average of the 20th century and and here this is 0.9 degrees celsius above that average but it's well over one degree celsius above the pre-industrial value and so this means we're more than halfway to the two degrees celsius that has been talked about as being a limit for what nations around the world should try to restrict the the climate change too um so i've now added the annual values of carbon dioxide after uh 1958 this is from monolow from the measurements that were that were made there started by dave keeling and prior to that it's from uh ice core measurements and bubbles of air that have been trapped in ice in greenland and Antarctica and we have really good confidence in this but this is the overall changes in the carbon dioxide now put these together in a way to suggest that there's a relationship between them because we think at NCAR we can clearly prove that they are related to one another and so that the the trapping of the greenhouse gases in the atmosphere are responsible for the overall picture of of a warming climate here and the fact that 2015 is warmer so this is also potentially affecting um the the weather and climate that we see around the world however it's it's not completely independent from El Nino events what i've done here is to show you here's the El Nino and La Nino sequences down below this is the 97 98 El Nino and so it's carried up here and then at the end of an El Nino event there's a warming and this is what happened in 1997 98 1998 was the warmest year in the 20th century as a result in part of that big El Nino event and there tends to be a warming at the end of many of these other uh El Nino events and so El Nino itself because heat comes out of the ocean into the atmosphere at the end of an El Nino event also affects the global mean surface temperature and so that is responsible for some of these fluctuations from one year to the next and one of the effects of this is that warmer air can hold more moisture and the rule of thumb if you remember one thing out of this talk it's that four percent more moisture per degree Fahrenheit thereabouts and so some of the consequences of this are that with global warming there's a little bit of extra heat available that firstly can go into evaporating moisture it creates more drying there's more evaporation and there's more moisture in the atmosphere because the atmosphere can hold more moisture and so the consequence of this is that there's more rain where it is raining and there's more drought where there's drought and so what I told you before is that the El Nino phenomenon is responsible for where the droughts and the floods or the heavy rains occur and then what global warming does is it exacerbates those it makes the rains where they are occurring rain even a little bit more and the drought set in a little quicker and increase the risk of wildfire and so the combination of these two things is then very much responsible for a lot of the devastation that has occurred around the world in the past year and I'm going to go into that very shortly and I need to try and move a little faster I guess so with regard to El Nino it's it's not altogether clear how the phenomenon itself will change with climate change the the changes certainly seem to be relatively small compared with the large fluctuations that we see but it is clear that the consequences become greater the droughts become more severe the heavy rains become more severe in where they occur so now let's look and see what's happened around the world in the past year and what we're what I'm the reason I've done it this way is because what we're seeing is not just El Nino and it's not just climate change it's the combination of both so one example that clearly would not have happened without the El Nino was this major cyclone it was a category five storm in Vanuatu if you don't know where Vanuatu is his Australia here and it's down here off the east coast of of Australia in this in the south Pacific and here's this major category five storm that caused absolute devastation there in March of this year there was a tremendous flooding in in Texas and Oklahoma here's the here's the rainfall is the amount of the rainfalls that occurred and and you may remember living in Colorado it was actually very wet in May of Colorado here so we got a bit of this as well but it was much worse in Oklahoma and Texas and you can see some of the pictures shown down below and the reason we think this is very much related to El Nino show is shown here this is actually corresponding to what is called the outgoing long wave radiation anomaly don't worry about that it just means that where the blue is is where there's a lot more rainfall and you can see the rainfall at that time was very much out around the dateline but extending to the east and right up into the southern parts of the United States there was a very clear connection into the United States that was responsible for that pattern in the summer of 2015 there was a tremendous number of thunder of thunderstorms tropical storms hurricanes and also typhoons and so this is a spectacular picture where there were three storms very unusual to see this one over here is kilo there's a another version of kilo here and this one actually crossed the dateline and so it went from being a hurricane to being a typhoon because once it crosses the dateline it's given a different a different category and and there was some tremendous damage in the Philippines and China and Taiwan and Japan is some of the flooding that occurred in Japan on these pictures on the right here so more category four and five storms and ever before on record a combination of global warming and El Mino of course we also saw all of these wildfires along the west coast starting earlier in California but also in Alaska even and then in Canada northwest part of Canada and then later on developing further in California and also Washington and Oregon at this stage here in August tremendous amount number of wildfires and and part of this is because all of the action was out over the pacific and so well as you know it never rains in southern California according to the beach boys at least in summertime and and so 2015 has been the costliest on record and it's very much related to to some of these patterns that developed um there was major flooding in in south Carolina in particular that relates to sort of the tail end of some of the storm tracks that can occur and we're seeing a little bit of that in the next few days as well but tremendous numbers amounts of rainfall record breaking rains in in that region of the country and then over on the western side of the pacific there's been major drought in indonesia i referred to that before but this is a picture actually showing all of the wildfires that were that were occurring tremendous number of wildfires and damage as a result this is actually in Borneo and there's been tremendous drought in in south africa this was a headline from Reuters and not very long ago south africa's worst drought in memory adds to the economic gloom there's a graph here showing indeed that it's one of the worst droughts in in many places and it's also been very droughty in in places like ethiopia but there's been major flooding in the southeast part of india in Chennai in particular Chennai used to be called madras and this was throughout the month of november and then into the first week of december this is in this region here just tremendous amount of rain falls and it was because the bay of Bengal was so warm and and the reason it was so warm is because all of the action was out in the pacific and so there is sunny skies and light winds over the indian ocean the indian ocean warms up and the atlantic ocean warms up in a similar fashion so it's in the latter stages of the El Nino and you know we're getting to that although the indian ocean's running a little bit ahead of where normally would be and as a result there has been tremendous action in that region and then there was the Missouri flooding that I referred to earlier so this occurred in late december this is a partial map for just a few days showing the swath of of heavy rains this is a satellite picture at the peak of them here and then a little bit later you'll recall there was some major tornado outbreaks in this region down here and for them for the state of Missouri as a whole in 2015 for november-december there was three times the normal rainfall the normal rainfall is about five inches and there was over 15 inches in the month of in these months in 2015 the previous record was roughly double or between what 11 and 12 inches in 1982 and 1992 and both of those were El Nino years but you know given the first part of this record if you're a statistician you look at the first part of this record you would never possibly think that you could get a value this high I don't know what the number is but it looks like a thousand-year event or something like that but all too many of these have been happening along the Mississippi and at the same time in the southern hemisphere in Paraguay in particular there was some major storms different character with tremendous flooding that was occurring down in there and this is the southern part of that anticyclone going into South America and so turning to the forecast what we expect in the future this is the forecast that was made by Noah on the 17th of September 2015 suggesting that the precipitation would be above normal in the south and below normal in the north and the temperature would be above normal in the north and below normal in the south and so what I'm going to show you in the next next graph is the actual what actually happened for this and so this will give you some sense perhaps of how much reliability you can place on the forecast and so has October November December of 2015 you can see it was very wet down here in Texas and and across in here but there was also wetter in the northern plains it wasn't really drier up there the storm track didn't stay away from there entirely and of course it was extremely warm in the eastern half and you know temperatures above 70s along the east coast around Christmas time no white Christmas for them and and so I don't know I'll go back that's what they were forecasting and that's what happened so how would you grade that I mean there's some things there's some things there that you know maybe have the right idea but you know it's not it's not exactly a match so this is the forecast for the next three months January February March all right and it's very similar a lot of this relates to the statistics it's wetter in the south the expectation is the storm track is more active across the south that's not what is happening right at the moment but maybe it can happen and and then it stays away from here at the moment the storms are still barreling into northern California and making it feel the wet up in here and then above normal here and below normal in the south and Colorado you'll notice right in the middle very little in the way of expectations even here it suggests that maybe there's a chance for it to be a little bit wetter but Colorado tends to be between this these two regions of above and below normal and so there's not a huge amount to be said for what actually goes on in Colorado the actual character what we call the different flavors of El Nino matter so other small subtle more subtle effects can play an important role so here's a picture now of what has happened in this key region in the tropical pacific in past El Nino events there's some weak ones here and then the red one is is 1997-98 the blue one is 1982-83 and so the sea temperatures went up and they peaked in December or or January in 1982-83 here's the 2015 event here and you can see in this graphic it's actually showing a little bit higher than 1997-98 but there's a hint here that maybe it's already peaked and and is on its way down and so the forecast is that it looks something like that returning to basically zero or or neutral conditions by about May or June of this year so El Nino will still have some strong influences in the next few months and maybe into the spring and in the spring sometimes there are good prospects for some heavy rains in the Mississippi region as we saw in in December well I should say this is the actual forecast the strong El Nino is expected to gradually weaken through the spring of 2016 and a transition to Enso neutral during late spring or early summer that's the official NOAA statement that was released earlier this week so my summary is that El Nino's occur naturally and with better understanding of El Nino we can predict the risks and facilitate planning and turn it to our advantage so this means you know there I think there are prospects that we can make better forecasts global climate change is also occurring though and that is human made we know which direction that's going and we need to slow the rates of change so that we can adapt to the changes as they occur and plan for the consequences so this is one thing that you might take away from here next time your spouse tells you to do something here's your answer and I wrote an article related to this which is available and what I did was to put that all of the words from that article into this thing called a wordle and create this word cloud and this is these are the words that I hope you've heard me talk about here and the things that are actually important in the El Nino phenomenon so you can spend quite a bit of time studying this and so here's the contact information for me this is this article that I just referred to it was published in a in a place called the conversation and here's my contact information there's a bunch of cards out there if I click on this it will actually take me to that website for the conversation and this is available on the NCAR website you can click on it there you don't have to necessarily write it down but this was the actual article that was that came out earlier in December there's this figure that I showed you here and some pictures and why does it happen and so and there's this figure that you saw before as well and so it's a it's a short readable article if you weren't taking notes this is where you can get your notes from all right and so we can go back to this and um I think that's it thank you well thank you very much Kevin we still have time for questions the only thing we ask you is that we speak to a mic so our listeners on the webcast can also hear the questions hello thank you very much for your talk this evening you'll have to bear with me as I read my scribbles as I was listening to you my question is how does NCAR and vision apply so related modeling to maturing predictive effects modeling that might enable a government or industrial response to take preventive or protective action in advance of a very strong event I have one slide that's hidden here that may help I went to a meeting that was held at Columbia University at the International Research Institute in Columbia that was taking stock of the state of knowledge and the capabilities for forecasting of El Nino events but it was looking a lot more at all of the capabilities for dealing with that information how we can actually use that information in different sectors of society and so this these are some of the some of the summary information that have occurred and and the contrast was was what happened in 1998 1998 was when the term El Nino really came into the American vernacular but before that it really was just a scientific term I think and so you know the suggestions were that the models in the forecast have improved my comment is that you know not as much as they they should have I think we've lost sight of some of the need to focus on this and we can do better but there have been a lot of institutions both private and in the government that are more adept at using the El Nino information for and and the forecast for planning and for prevention and for preparation and and building resilience of different kinds and there's certainly places in the tropics and perhaps Australia is one of the best places where they where they try to put out warnings in the farmers in particular are taking advantage of this and they cut down the risk of wildfire and they they move stock around and and and and do various things to prepare for either El Nino or El Nino conditions the same is happening in South America with regard to hydropower and things like that and so the general sense is that there's a quite a lot greater awareness about El Nino and its impacts and also what to do about it there and so there are places like in Peru where where they switch crops and have even grown rice under El Nino conditions where normally they would never be able to to grow rice and so you can actually completely change the crops if you know that it's going to be a lot wetter than normal and and take advantage of things like this and so this is the this might very short summary statement is that if you can forecast this reliably and provide some kind of a warning even if it's not a detailed day-to-day weather forecast then you can be much better prepared for this I think there is considerable scope to do better this partly relates to monitoring and tracking and observations and and satellite measurements tailoring some of the products that come out of this and and then there's the social science aspects and communication on how you use this information and and build resilience and and make yourself less prone to be affected by these kinds of extreme so having the expectations that these kind of things will occur can help you be prepared for them I hope that helps but if you can do all these things and you said that there's not a real good understanding of how climate change overlays on El Nino then the effects are much might be much stronger than you could predict from this is that correct yes well it's you know the climate system and and the atmosphere and the ocean are very complicated systems the way I think about El Nino is that as I sort of described here is that in La Nina events there's a tendency for heat to build up in the ocean and the ocean actually stores heat and some of that heat gets stored well below the surface but during El Nino events some of that heat spreads across the Pacific and comes back into the atmosphere so it it comes back to haunt us not all of it can can do that but to the extent that it it does that and it moves heat around then it makes sense that with global warming which is also dealing with with heat extra heat that there should be some change in the character of El Nino events and and so one of the questions is given that there are three super El Ninos in 1982 83 97 98 2015 16 and not 100 years before then our super El Ninos one of the symptoms of climate change to do to to really have confidence in the answer to that question we would like to be able to simulate these events more reliably in our climate model so this means understanding all of the aspects of it in detail and it deals especially with the complex processes of rainfall and thunderstorms and the interactions among with with typhoons and tropical storms and so on and so this is a major challenge because you're dealing with individual events that are a mile across dealing with a thunderstorm to thousands of miles across and even now the supercomputers that we have are not good enough that we can cover all of that huge range of scales altogether so we have to cover the global scales we can get down to maybe 50 miles or something like that but the thunderstorms and the smaller scale phenomena are not treated as well as they need to be in our climate models and this always gives us some questions then about can you trust the outcome from the climate models so this is one of the things we're working on here at NCAR in order to improve the the climate models and improve the representation of the things that we can't actually simulate all of the details of in terms of rainfall and you know ideally we need to get right down to the individual raindrops in the micro physics it's a very complex problem and in that respect it's very challenging mother nature can do it but we're not quite able to do it here at NCAR yet yes I think we had a storm called Goliath before Christmas was that read the right name and it seems to me that to have a storm go all the way from the west coast to the east coast I don't just don't remember that and I watched the weather pretty carefully how how is there enough water to last that long to cross the whole country and still flood the east coast well moisture in the atmosphere molecule of moisture in the atmosphere has an average lifetime of about eight or nine days something like that it depends a little bit on on where it is but this is what enables monsoons to happen the moisture that gets rained out over southeast Asia comes actually a thousand from a thousand to two thousand miles away it gets transported by by the atmosphere over those kind of distances but so the water is continually cycling through but it has to keep having a supply of moisture through the winds and so you know if you have a big storm over Ohio say the moisture that's flowing into that storm is coming out of the Gulf of Mexico and out of the tropical Atlantic it's coming from 1500 miles away and it's flowing into that storm if something happens to shut off that flow of moisture then indeed the storm will peter out but a lot of it relates to the the storm circulation itself and so the the key ingredient is indeed the larger scale winds that are consistently supplying moisture to the storm hurricanes are an excellent case in point maybe this is off the subject a little bit but if you ever thought that it's amazing you can look down from the satellite from a satellite and you can see the hurricane you can see the edge of it how how come it's not always blurry and mixed up with all kinds of other stuff well it relates to the hurricane circulation there's the hurricane itself where all of the rising air is occurring but then their air flows out at the top of the hurricane and it subsides in the region around and so the air around the hurricane is clear because the air is subsiding in that region and so it turns out the circuit the average radius of a hurricane is about 400 kilometers 250 miles but the the circulation of a hurricane is about four times that it's about a thousand miles and so the moisture spirals into that hurricane from about as far away as a thousand miles away even though the visible picture of the hurricane is only 250 miles across and so it sort of indicates the important nature of the overall region the environment that is feeding in this case the moisture into the storm and that's exactly the sort of thing that we're talking about thank you for your presentation my question is not about El Nino but about your specific graph on the climate change CO2 and temperature and in the context of the disbelieveability or whatever of climate change is that the form of the presentation with the CO2 overlaid on there I would have expected a noticeable lag between increase in CO2 and the increase in the temperatures that just the result of the way this is presented or what that's what's partly the way this this is presented yes there they've been set up to more or less align with one another so I can move one up and down or or and effectively by moving it up and down you're you're also moving it a little bit to the left and the right and you know carbon dioxide has a long lifetime and so the effects indeed continue into the future but but not into the past and so it's not symmetric in that regard okay yes I we we are all here on by choice we are eager we're to varying degrees informed and interested but there's a large amount of skepticism and lack of education in the public schools about this and I'm wondering if you have a vision or ideas on how best to bring education to public schools how to inform so this ceases being what it is the a political opinion rather than a scientific fact well there I mean the thing about climate change is that there is a tremendous number of observations this these these two graphs here are based upon information observations and there is a tremendous amount of other pieces of information sea level I mentioned before that we have new measurements of sea level sea level is going up at an average rate since 1992 when we've had these altimeters in space at a rate of 3.2 millimeters per year so 3.2 millimeters you go to a century that's 32 centimeters so it's a little over a foot per century in other words that's the rate of rise of sea level how does that happen it happens because of melting of glaciers put small water into the ocean and it happens because the oceans are warming and we can measure that separately and the oceans are warming and expanding there is unequivocal evidence that the planet is warming and and there are multiple lines of evidence and so the role of scientists here at NCAR and elsewhere is to assemble this information to synthesize it as best we can try to say what is happening and why and what we then expect the future will look like so that's the role of scientists the role of you and the the general public is to say what you do about this if we tell you that the planet is warming and that we expect that as a result there will be more intense hurricanes and heavier rains and stronger droughts and and other things like that one of the options is that you can live with the consequences and that's partly what we're doing at the moment another option is to as we discussed before try to build resilience adapt to it in in various ways not build in flood plains or or take away the houses that are in flood plains and take various other kinds of actions but you know one of the best things we can do also would be perhaps to slow down the rates of climate change the rates of increase of carbon dioxide in the atmosphere that are responsible for this so that's another option that's not for us scientists to say what that is we can certainly try to provide guidance as to what we think the actions would be and this is what the incremental panel on climate change actually tries to do there's one group that deals with assembling all the information and and trying to model it and understand what's going on and make projections of the future there's another group which deals with the impacts of everything and and the adaptation and how you can actually go about and better build resilience but then there's another group which deals with the so-called mitigation what options can we take in order to slow down or change the change the outcomes in the in the future relating and this relates very much to what happened in Paris what was it a month ago now with the international agreement to try to reduce emissions of carbon dioxide into the atmosphere and therefore slow the process down and at least if that happens it gives us a better chance to plan for it and adapt to it as as the climate change occurs so I agree with you that there's probably a need for much better education at many levels and especially in in the high schools this is an important topic and unfortunately because of the political aspects of it and and the vested interest there's a tremendous amount of money which has been spent to carry out the disinformation campaigns so it's probably going to be an issue in the current election I suspect but that's that's over to you guys if we add to Kevin's answer so we do have some programs here to educate the public we have climate voices which is a program where you can ask for a speaker to come to your community and the schools are open to doing that that's climatevoices.org we also have the UCAR Center for Science Education and they work quite a bit with teachers they train the teacher so then they can take the information to the schools and there's larger organizations like American Geophysical Union and American Meteorological Society so every year at those meetings we host educational sessions for teachers primarily so we hope by educating the teacher that trickles down to the schools. I'll pass it to Terry because you have a question. I have a question about the chart that showed the overlays of the last few El Niños I'm back here Dr. Trenbev I really like that chart it was showing how they peaked right in December and I thought that the changing of the tilt of the earth and the sun would lower the temperatures and cause that cold water to come across and sort of short circuit the El Niño so there's no question that El Niño was a one-year event it doesn't it could never go on for more than one year code it. Well in some sense you run out of warm water but this relates what I started with and it relates a little bit to the setting and and so along the equator the trade winds are strongest and the water in the eastern Pacific is coldest around September, October and it's warmest around March, April, May and so that's when the winds tend to be weakest as a whole and so there's a very distinct annual cycle to the winds and the sea surface temperatures in the tropics and so this what this means as it turns out is that March, April, May is the time when it's easiest for the El Niño to switch from being an El Niño to a La Niña or vice versa this is when most of these events tend to kick off and you can see that on this particular particular graph here that all of these El Niño events which are peaking around Christmas time had their origins back in the northern spring and then they're also ending in the in the subsequent spring they tend to so they have this overall cycle of about a year but it's very much related to this overall evolution of the total sea surface temperature field and then these anomalies are built on top of it so I mentioned to you before that the sea surface temperatures anomalies the departures from normal tend to peak around December but the total sea surface temperatures actually peak a little bit later and that's one of the reasons why some of the biggest effects are not in December but rather in January and February and in fact in October, November and even part of December some of the biggest effects are still occurring in the southern hemisphere and the seasons are still evolving a little bit and transitioning to where the biggest effects are in the northern hemisphere so all of these kinds of things are are going on as well but that's sort of a part of an accounting for the interaction between El Niño and the and the mean annual cycle. Kevin I have one from a sixth grade teacher speaking of education and she's actually teaching El Niño right now I'm not sure if she is in Colorado she doesn't say but she wants to know how El Niño is likely to affect the snowpack in the mountains of Colorado this year. Yes so we have go back to the beginning here where I showed you some slides in fact let me show you the latest slide I didn't actually show this one but this is today this is the satellite picture today this is the next storm that's coming into the west coast and you can see there's not much going on down here in the south which is where it's forecast to the action is forecast to occur by NOAA but anyway there are no prospects of that in the next week or so and and this storm as it goes across is expected to develop and cause a big storm on the on the east coast region. Up till now the snowpack is I think I mentioned before about a hundred percent of normal in the northern parts of Colorado but it's 110 up 110 115 maybe 120 percent in southern Colorado so because these storms have been tracking a little bit further to the north they've been coming across and actually dumping quite good amounts of snow in the mountains this year but that's not actually one of the characteristics we would normally expect with El Nino events and in fact if you look at El Nino events overall there's a there's a slight deficit I think in the mountains. I have two questions which are not related one is to what extent does salinity change in the water of the ocean come in because it's bound to come in the temperature change that's the first question second question is on your graph with CO2 if you added methane which occurs is a more effective greenhouse gas by the shorter lifetime but also one worries about its amplification due to the permafrost and everything else how that will influence it. Well methane is a greenhouse gas as you say its lifetime is about 10 years there are natural sources of methane which are being realized as the permafrost thaws and more of the vegetation matter can generate methane so those of you who have a compost heap if you've ever had a compost heap if the basic idea is to get the vegetation matter to decay and if the compost heat is wet it decays rather slowly with a certain kind of microbial activity and generates methane it's a methane is also called marsh gas and so a wet environment is apt to create methane but if you can dry it out and make a more healthy compost heap it will generate the different kind of bacterial action will work at a much faster rate and it will actually generate carbon dioxide and and so that's where the the compost heat remains dry and so what happens as to whether you get methane or not depends upon how whether the bogs actually dry out or not and and what kind of bacterial activity prevails but it really depends mostly on whether it's wet or dry but there are indeed prospects for more greenhouse gases coming out of the ground because of the vegetation matter which is buried in the ground that that can produce produce these things but on a time scale of about 10 years the methane actually ends up as carbon dioxide so it gets oxidized it gets burned or something like that i don't know whether that quite answered answered your question in that regard but it's one of the greenhouse gases that contribute somewhat to global warming but certainly the big one because of its long lifetime is carbon dioxide and because of its volume the the first question relating to salinity salinity is certainly important in the ocean the density of the ocean depends upon both its temperature and the salinity and i didn't go in into salinity but obviously in the tropical pacific where you've got heavy rains you've got fresh water coming down it does alter the salinity and it's only in the last five years or something like that we would have actually had salinity measurements from satellite of the of the near surface that have been we've been able to map salinity reliably and subsurface salinity has been mapped by so-called argofloats reliably on a global basis since about 2005 so about 10 years something like that so in in terms of oceanography and the effects of this on the on the ocean currents that's been one of the things which has been lacking and which scientists are just beginning to understand and grapple with and and as a result this helps us build better models but salinity is certainly an issue for us and we need longer periods of good observations in order to help build full understanding of that it'll take just last question back there thank you very much in the paper i had i had two uh two questions the first was in the paper yesterday there was an article that said there was a research study that said in the last 18 years 150 zeta joules of heat energy went into the ocean and that from 1885 to 1997 same amount 150 zeta joules of heat went into the ocean so it seems like things are accelerating rather rapidly how fluid is the is the heat energy going back and forth from the atmosphere to the to the ocean it seems like from the article it goes in there and pretty much stays there and then my second question was just an anecdote um when i i've been living here since the 70s and it seemed to me that the uh that were many more sustained wind storms you know of higher peak velocity at least on my farm throughout the 70s than there are now it seems like it's much more pleasant in fact one of my colleagues left here for Nebraska because the wind was too much for him here but i stuck it out and it seems like everything's okay now i think you're probably right i i i don't have those statistics at my fingertips but my own impression is somewhat similar but back in the 1970s there were a number of cases where houses lost their roofs and there were a number of downslope winds so-called chinook wind uh chinooks that that occurred and we haven't seen as many of those in in recent times um they have their worst effects in winter and they rely very much on the right kind of setup of of storms across the mountains the pressure gradients being being set up and we often get those in the spring but we've had those in the spring but they haven't they don't produce quite such strong winds as they might in january say so i i don't know the full answer to to that question but i think your impression is probably correct um the first question with regard to burying heat in the ocean uh it's mostly a one-way process because if the climate is warming as a whole and the atmosphere is warming the oceans gradually have to warm as well and and so heat overall is is actually mixing into the ocean and some of that is what scientists call irreversible mixing it can't come back very easily el nino is a unique circumstance where a lot of warm water piles up in the western pacific and and some of it is available to come back and that's but it's a it's a only a fraction of the total amount of heat that's going into the ocean and uh we have some new analyses here at encar which actually suggests that the study you referred to underestimates the amount of heat that's gone into the ocean we find that there's there's even more heat going into the ocean and of course this is what is responsible in part for the sea level rise and we can reconcile our values much better with the actual values of sea level rise than they can in that particular study we find also that about 44 percent of the of the heat is going below about 700 meters into the ocean 44 percent that's quite a lot and uh and the sea level the rate of warming of the ocean is certainly accelerating and it's much greater after the mid 1990s than it was from say 1970 to 1990 and in turn that was much greater than the first 70 years of the 20th century okay so it's almost 8 50 p.m so I will end the official q and a period but if you still have questions for Kevin he's going to be around for the next 20 minutes or so so feel free coming up as you leave if you could leave your evaluations with Teresa or we have a person outside on the other side that's feedback would be really valuable to us so thank you again for coming there's pencils out there and have a wonderful evening