 So, next one hour I am going to talk about the monsoon, monsoon and scale interactions. All the monsoon is global. I think I have not enough time to cover everything. So, mostly I will focus on like Indian monsoon, South Asian monsoon, South East Asian monsoon, and probably I will slightly touch on the African monsoon and South American monsoon. So, talking about the Indian monsoon, mostly South Asian monsoon, we have like summer time wind coming to the Indian subcontinent, South Asia and bringing moisture and rainfall to India and South East Asia. However, during winter time the winds are reversed and that is why it is called monsoon because winds reversed and then northeasterly wind come in from like Siberian region and northern high light shoots and then when they come over Bengal pick up some moisture and that is why you get rain over eastern part of India and this year it is substantially higher. So, most part of Chennai and this part of India is flooded. The monsoons are linked with several processes. I have put some processes here and also climate modes. I just presented about the climate modes this morning also we talked about it yesterday. Cyclones are not directly related to the monsoons because during monsoon time we have strong winds here between low level and high level. So, the winds here does not allow cyclones to develop. That is why cyclones are not directly related to monsoons in the Indian Ocean. However, many studies have linked cyclones in Pacific like if you have more number of typhoons in northwest Pacific that diverts moisture from Indian Ocean. So, that is why monsoon become weak sometimes due to high frequency variability in typhoons in the northwest Pacific. Of course, we have the MGO and the intracellular oscillations and then the active phase those are related actually MGO, ISO and active and break phases of the monsoon and then of course, we have the climate modes, Indian Ocean dipole, the subtropical dipole, Ningalurino is not so much related, Elino-Modoki, Elino and the Indonesian through flow. The through flow affects the heat content of the basin Indian Ocean and in that way it can influence the monsoon on several timescales from inter-annual, multi-annual to decadal timescales. Let me start with Indian monsoon and so IOD connections because ENSO has been thought to be the dominant influencer on the Indian monsoon. Basically, the Southern Oscillation was discovered while Gilbert Walker was trying to understand why monsoon failed in late 19th century and early 20th century. He was the Director General of India Meteorological Department in early 20th century and he was under pressure from the British government because British government was criticized for not managing the droughts in India in late 19th century and there are several droughts and turning into famines and mass mortality and then while trying to relate the Indian summer monsoon index with several indices because he was able to get all the data, meteorological data from many stations all over the world, so at that time he tried to correlate the Indian monsoon index with all those atmospheric data he had and at that time he discovered that when there is a sea oscillation between eastern Pacific and western Pacific like the difference between Tahiti and Darwin, that index could be related to monsoon and then he found that Southern Oscillation can explain some of the droughts in India. Of course that time he also discovered NaO but NaO was not so much linked to the monsoon and later I think we have many studies which also try to understand the ENSO monsoon relationship using paleoproxidate records. Like in this study Cook et al. 2010 try to understand the monsoon variability in relation to ENSO using tree ring data. So they extended because we have limited number of observations and the record is not so long so they used those proxy data to identify some of the mega droughts in 19th and 20th century like they extended the record to 1400 to 1200 and then they found that most of those droughts and floods are actually related to either lanina phase of the ENSO or the lanina phase of the ENSO. And if you look at the present days like these two are Indian monsoon rainfall patterns for 2006 and 2009 both of them are lanino years 2006 was an lanino year 2009 also was an lanino year. If you look at those two rainfall diagrams you can see that 2006 the most of the regions in India received quite normal rainfall or sometimes even above normal rainfall. And the overall deficit for the whole India was only 1% which is not much considering that it is an lanino year and considering that historically we know that lanino has strong influence and whenever we have lanino India suffers from a drought however 2006 was not so bad. Now compare that with 2009 another lanino year 2009 was slightly different 2009 we had lanino as well as lanomodoki kind of blended lanino and lanomodoki year and you can see here the whole India rainfall was minus 22% of normal so very dry year in last 15 to 20 years. Although both are lanino years one year was severe drought the other one was not so bad and then compare that I am coming to that building it up and then compare that with this year 2015. In 2015 initially we almost all models were predicting a very strong lanino and some people even saying that it will exceed the 1997 event and called it a Godzilla event Godzilla lanino however if you look at the deficiency the all India rainfall was minus 16% less than it is of course it was dry but less than 2009 event and again it was a strong lanino quite comparable to 1997 although it is not as strong as 1997 and then this is the time series of all Indian rainfall from 1870 to 2010 taken from India meteorological department sorry IITM homogeneous India Indian Monterey rainfall index and here the red circle means those are the lanino year so basically you can see all the deficit years below normal years are related to lanos all are red circles here except for few events here and mostly happening up to 1980s so these three events although it was those were lanino years the rainfall was not so below so much below normal and that as you are asking is related to the Indian ocean this is the Indian summer mountain index in black line early 20th century first 10 years of the 20th century and the blue line is the southern oscillation index discovered by Gilbert Walker and he was the director general at that time you can see that the correlation is almost one between them the Indian summer mountain rainfall and southern oscillation index correlation is almost one when he was the director general we don't know whether he played with the data which is mostly unlikely because pressure from the government and then correlate the same thing for the last 10 years of the 20th century 1990 to 1999 in this case the correlation becomes 0.1 in significant negligible so that means the NSO the southern oscillation influence on monsoon is not so strong in the last part of the 20th century and at that time during here around 1999 we discovered that Indian ocean also has its own oscillation which we call the Indian ocean dipole and whenever we have Indian ocean dipole we also have a kind of sea so oscillation between eastern Indian ocean and western Indian ocean and when you have a positive Indian ocean dipole it will like divert the moisture from eastern Indian ocean converts that to eastern Indian ocean and also India so that's why the NSO influence which used to be like subsidence over India was reduced by this kind of dipole in the Indian ocean and the correlation between the dipole index in the Indian ocean and the Indian summer monsoon is 0.5 and schematically it can explain that like if you don't have Indian ocean dipole the Darwin high pressure becomes very widespread and covers parts of India so that's why we have subsidence over India and less rainfall however if you have a dipole in the Indian ocean then that will reduce the impact of the Darwin pressure high pressure here high pressure anomalies and then help the Indian summer monsoons to revive even with the ellenose and this is again the same story once we have a divergence from here because of the cold anomalies the convection over maritime continent will be suppressed and the divergence of moisture from that area will converge to western Indian ocean as well as Indian monsoon trough so that's why you get more rain during positive Indian ocean dipole and that explains when the Indian summer monsoon rainfall and ellenone correlation has decreased the Indian summer monsoon rainfall and the IOD correlation has increased became significant. We also observed that in proxy data in this case we are using the coral records coral IOD index the index taken from Victoria lake corals of Victoria lake in Kenya because Kenya gets more rain during positive Indian ocean dipoles and get less rain during negative Indian ocean dipoles so that's why we have a dipole index taken from the coral records we can extend the time series to 1880 1890 and we see that when the Nino 3 and Indian summer monsoon rainfall index less than it decreased the coral IOD and monsoon rainfall correlation has increased it was not that strong before 1940s and 50s and we attribute that to the more ships or the decadal variability within the Indian ocean dipole like before 1940s and 50s the dipole used to have a pentadal time scales and before 1930s it used to have like a decadal time scale so it was not occurring so frequently before 1950s but if you see after 1980s we have kind of biennial oscillations the IOD became more biennial so you almost expect every alternate years a positive Indian ocean dipole and even if that happens even if there is an Lino the Indian monsoon doesn't suffer so much so that's why the relationship between Indian monsoon and the dipole index became stronger after 1980s then how do you explain that behavior in the Indian ocean dipole why we have so frequent Indian ocean dipole in present decades to some extent we can explain that through the warming of the Indian ocean the whole Indian ocean is warming because of the global warming however the western side of the Indian ocean is warming stronger or more than the eastern side and that is creating some kind of background gradient between east and west favoring more number of positive Indian ocean dipoles and that's why we start observing consecutive positive Indian ocean dipole years in recent time which was not so much actually we didn't see any consecutive positive Indian ocean dipole in instrumental records from like early 20th century to almost end of 20th century only recently like 2006, 2007 and 2008 all three years were positive Indian ocean dipole so here we are now experiencing a situation where we have we have a background state which favors more positive Indian ocean dipoles this is also this is also observed by another study done by Abram et al from coral records taken from Sicilis as well as Sumatra region so they made a dipole index using coral records from Sicilis and Sumatra and from that index they also found that the positive Indian ocean dipoles are intensified in present times and looking at the projections also some studies like Chai et al from Australia they also used the CMIF5 model results to find that we expect more number of extreme this they explain as extreme UF1 as their extreme events extreme Indian ocean dipole events and this is moderate Indian ocean dipole events note that these are UF so you can always turn around the patterns and then they observed that compared to 20th century the extreme number of dipole events can be seen in the 21st century actually more number of extreme events can be expected in the 21st century based on those CMIF5 model experiments so all those are indicating that we are in a state which is supporting more number of Indian ocean dipole particularly positive Indian ocean dipoles so why we are so concerned about Indian ocean dipole because of the not only the interlink with monsoon but also because of its teleconnections to several parts of the world in this case I am showing you how the positive Indian ocean dipole could be linked to like the European summer conditions heat waves in Europe. In 2003 we had a positive Indian ocean dipole which only lasted for a couple of months it started in around end of July and almost died by end of August and that happened because of M0 I will show you that later but at that time what we observed when the Indian ocean dipole came to a peak the heat wave conditions over Europe were intensified so the blocking high in Europe and Indian ocean dipole were somehow linked on those high frequency time scales not on seasonal time scales and then of course at that time we submitted a paper to nature and it was immediately rejected we came to know why because after sometime one paper was published saying that it is related to global warming however what we found later is that whenever we have a positive Indian ocean dipole as I said eastern side become dry we have subsidence and less convection on the western side we have higher convection and more rainfall particularly over the western Indian ocean India and Pakistan and that rainfall once we have that rainfall the diabetic heating caused by that rainfall can be projected on to the middle-actured jet stream so once we have a diabetic heating and that can generate anomalies in the vorticity and that can be projected on to the jet stream which will then act as a kind of anchor to carry that signal all the way around to Europe through that jet stream which we call the waveguide I think we just heard this morning about the rugby waves and these are the long rugby waves they propagate eastward and the jet stream here usually we have a jet stream here usually the jet stream is not elongated and not like Sarkoong global but some years they become quite strong and can be Sarkoong global and that provides the anchor for the signal to propagate eastward once we have a diabetic heating here that will project on to the jet stream here and then propagate around the globe to reach the the eastern and western Europe and and like support that blocking blocking high this is one of the reasons of course there are several other reasons why you have a strong blocking high during those heat wave years over Europe and one part of that stream that jet stream also goes like to Arctic and also some people link that to Arctic sea ice melting now to support that hypothesis I'm correlating the Indian Ocean dipole index with the European dipole index so what we what we did is like because whenever we have blocking high you also have a low system here so we took a dive we took an index by taking difference between Eastern Europe and Western Europe and then correlate that with the IOD index for March April May July August and September October November so we can see that the dipole is highly correlated 0.51 and 0.45 for the European dipole index and the Western Europe it's not so much related to the Eastern European index and compared to that the Nino 3 index correlation is not so high sorry the the see yes the Nino 3 and so influence is not so high for the European dipole index and the Western Europe index although it is quite high for the Eastern Europe index and compared to those two tropical climate modes NO is not so well related so it's quite I think logical to think that Nino has not so significant influence during summer time because Nino is basically a strong phenomenon during winter time as I was mentioning you the one part of that jet stream like wave train goes all the way to the to the Arctic and in one paper recently said that this pathway can be related to rapid Arctic ice melting so recent ice melting in the in the Arctic could be related to Monson activities strong Monson activities and probably those are where those were related to the Indian Ocean dipoles the wave train also can be seen in southern hemisphere and we find that the Indian Ocean dipole related to the Monson activity over the tropical Indian Ocean can be traced to Laplata region like we have whenever we have positive Indian Ocean dipole we get depth sea terrain in southern Brazil but enhance rain in northern Argentina and that also verified in the syntax of simulations the the the coupled model we presented yesterday that also simulated the same phenomenon ok besides teleconnections we also have direct influence of Monson on the on the rainfall of southeast Asia in one of the studies recently showed that the March April May and September October November rainfall of Indochina Peninsula here Myanmar Thailand Cambodia in that region that rainfall is more related to the Monson activities over the bare Bengal and Indian Ocean compared to La Nina or Elina in the tropical Pacific and that sometimes explains like like if you have a strong westerlies in the bare Bengal that can charge the Monson and also charge the also produce rainfall and charge all the fields so whenever you have a kind of cyclone followed by that Monson event we expect this kind of floods like what we saw in 2011 Thai Thai flood coming to the predictability like we showed yesterday most of the predictability in coupled model simulations can be seen in surface temperature rather than rainfall the predictability is higher in surface temperature compared to rainfall so that's why we have trouble to get high predictability in Monson rainfall as you can see here just I'll flip those two again and again you can see that the anomaly correlations of the skills are pretty high for all the seasons December January February March April May June July August and September October November you can see that the skill is pretty high for the tropical temperatures but it's not so high for the rainfall it's remains quite high for the December January February rainfall in tropical Pacific but not so high for the June July August particularly it's not so high in the Indian Ocean sector it's the skill score from our model and we can see the same thing in the multi-model ensembles like the study done by Binwan again the June July August skills for precipitation is not so high in the Indian Ocean region although it's somewhat high for the December January February when you do the multi-model ensembles now Kulkarni at all did one study in which they try to compare the predictability skills of Monson rainfall from several models this is the syntax frontier model from Jamstek and then they come here and some other models what we can see here is that most of the models were doing somewhat okay for the rainfall of the foothills of Himalaya like the northern provinces of India most models were doing okay mainly because those rainfalls are related to large scale Monson drop activity so because it is large scale the models coupled models with 100 kilometer resolutions were able to capture the rainfall variability in that region and the predictability was quite okay although not so high 0.4 to 0.5 however you can see that there was no predictability skill in the middle part of India central India and those part of India they get most of their rainfall from Monson disturbances Monson disturbances Monson low pressure systems and also the transient variability in the drop itself and most of those disturbances come from bare Bengal and travel across the central India and sometimes they go also to Pakistan so those high frequency variabilities are not captured by the model prediction so that's why the the skill score of model predictions were low over central India compared to northern part and southern part which were mostly related to large scale climate variations this is one of the examples where the syntax frontier model which we are using in down state failed to capture the Monson rainfall over India this is the case in 2013 we had a negative Indian ocean dipole which is somewhat okay with the observation this is observation and these two are model predictions and model was capturing quite well that negative Indian ocean dipole and whenever we expect a negative Indian ocean dipole the Monson rainfall is not so high it's below normal but it's also modulated by lanina conditions if you have a lanina with a negative Indian ocean dipole the Monson tends to be normal although the model was capturing those assistive anomalies well including the lanina condition in the tropical Pacific the rainfall was not well captured actually it was getting a negative anomalies for June-July August whereas it was observed that we had positive rain and above normal rain actually during that year and that's again related to the teleconnexions coming from tropical Indian and Pacific oceans because sometime model is not capturing the right phase and right space of the tropical convection so that's why the teleconnexions sometime get wrong okay so these are the challenges to improve the regional rainfall predictions the most important thing is to get those high frequency variabilities in the model predictions and then the intracisional oscillations in addition to that we also have some variations on decayed all time scales like the Indian ocean is warming and because of that we have some changes in the in the in the walker circulation and also in the Pacific decayed all conditions so we have more like lanina conditions now because of the Indian ocean warming and also because of the extra tropical variabilities and those things need to be captured by the model in order to get in order to get those monsoon rainfall predictability correct okay so next is the MGO interactions so this morning I presented you MGO so I don't have to tell you the basics of MGO already have that and we find that MGOs also interact with Indian ocean dipole and directly and indirectly with the monsoon and this is one of the studies where Rao and Amagata showed that the Indian ocean dipoles were terminated in the years which were not associated with Elinos 1961 1967 1994 and 2003 all those four Indian ocean dipole years were not related to Enso and in those years as you are asking yesterday in those years the the dipole was terminated by a MGO phase in the Indian ocean so whenever we have MGO that will kick in the downwelling Kelvin waves because you have strong westerlies which causes convergence in the tropical equatorial Indian ocean and that converging pattern which will cause high heat content because of because of depending on the thermocline and that high heat will move to Sumatra coast and will kill the positive Indian ocean dipole. During positive Indian ocean dipole the Sumatra coast we have upwelling and cold anomalies so if you have warm anomalies coming from the west because of the MGOs that will terminate the positive Indian ocean dipole and that is what is observed during 1961 1967 1994 2003 all those years were not related to Elino years. Significant one is the 2003 usually we don't see MGO during June, July, August MGO is very active during December, January, February and March, April may basically however some years we do get MGOs in June, July, August and 2003 is one of the years actually it was a good news for Europe because of that MGO the dipole got killed and the heat wave suddenly subsided after that event. We also see the same kind of thing in the model simulations like I forgot to tell you one thing during the years when the dipoles are accompanied or concurrent with Elinos like 1982 and 1997 we don't see MGO activities so those years the IODs get terminated because of the change in the monsoon wind in the maritime continent. When the winter monsoon sets in that will like kill the upwelling zone in Sumatra region and will help downwelling so the dipole will get terminated during those years so indirectly you can see that Elino and MGO are also linked so usually during Elino years we don't see much MGO activities in the Indian Ocean during November, December. This was also seen in the model simulations these are the model years not necessarily related to the calendar years and you can see all those years which were not related to model Elinos also were terminated by the MGOs in the model simulations. So how MGO influences monsoon rains one example here this is unpublished work so I am not going into the details of this one of our colleagues from Malaysia found that the phase of MGOs are somehow linked to the peninsular Malaysian rainfall their monsoon in November, December. And particularly they found that phase 4 and phase 5 after phase 3 when the MGO moves into peninsular Malaysia here during phase 4 and phase 5 particularly their west coast get more rain during those MGO phases. The Indian monsoon is not so much linked directly to MGO but it's linked to what we call boreal summer intracisional oscillations which move northward as you can see MGO move eastward but these ISOs in the Indian Ocean move northward and that influence the rainfall Indian monsoon rainfall and also south Asian monsoon rainfall. So here is a comparison given in the MGO working group in WMO MGO versus boreal summer intracisional oscillations also called as monsoon intracisional oscillations MISO. Comparing MGO usually MGO move eastward and they are 30 to 60 day modes whereas boreal summer monsoon boreal summer intracisional oscillations move northward like once we have some anomaly here they move northward northward or north westward and then help the rainfall active phase of the rainfall over India. There are two types of boreal summer intracisional oscillations and some of them are also 30 to 60 day and the other ones were bi-weekly and they move northward or north westward and they affect the monsoon onsets active and break phases as well as the whole seasons rainfall and the possible source for those seasonal climate predictability can be investigated by making an index like the RMM for the MGOs. This is the BIOSO-1 which is usually 30 to 60 days more and related to the UF-1 and UF-2 which explains like 7.2 percent of variability and 4.9 percent of variability. They are kind of statistically separated 7.2 and 4.9 they are statistically separated however can be considered as kind of a single mode with two different phases. One is a kind of dipole like structure the other one is quadrupole like structure and the first UF mode is more related to the Indian ocean trough here whereas the second mode is more related to the Indian ocean and north west Pacific and both of them move northward or north eastward that's why they are more related to the Indian monsoon. Maybe they are also kind of manifestations of rosby waves in this case short rosby waves moving westward and then we have the BIOSO-2 which is more like 10 to 30 days mode or bi-weekly mode and they are mostly related to like pre-monsoon and monsoon onset also sometimes they are related to extreme rainfall event over India and south east Asia. It's again like front like things so the UF-3 and UF-4 they are not so well separated so I think they are both kind of same thing. UF-3 is more related to south east Asia and UF-4 is more related to east Asia so UF-3 has kind of influence over south China and probably Malaysia and Philippines and UF-4 is more related to China and Japan monsoon rainfall during June, July, August and in one of the studies they found that 68% of the onset dates for the Indian monsoon can be explained by phase 2 to 4 of BIOSO-2 and 70% of the onset dates can be explained for the south China sea by this phase 3 to phase 2 to 4 like these phases BIOSO-2 and some of the BIOSOs are also related to extreme rainfall events like you see here over southern China and Vietnam we have extreme rainfalls associated with 5 to 7 days BIOSO modes. Coming to the predictability, this is one of the work where Avilas is involved, Don in IITM and in this study they try to find out the predictability skill in CFS simulations for 2001, 2003, 2007 and 2009. You can see that skill score above 0.6, up to 15 days skill score is above 0.6 for the MISO-1 and MISO-2 they call the BIOSO and BIOSO-1 and BIOSO-2 as MISO-1, MISO-2 those are basically similar, monsoon intracisional oscillations past mode and second mode and both modes you can see here the model has some skills to predict both modes up to 15 to 20 days ahead and that's about the predictability of the MJOS and the monsoons. Coming to the African monsoon, I am not an expert in African monsoon so I am trying to explain please correct me if I am wrong. We have the East African monsoon which is related to the sift in the ITCG in the Indian Ocean whereas the West African monsoon is related to the ITCG in the Atlantic and this part of the monsoon is somewhat well understood because there are several studies which try to link the ITCG movement here, the sub-tropical high in the Indian Ocean and the dipole in the Indian Ocean so what we observe is that whenever we have a dipole here East Africa gets more rain so the monsoon becomes strong on this side and whenever we have a sub-tropical high move slightly southward the ITCG also become active and we get more rain on the eastern side. The western side is less understood and as Adrian was telling this morning in 2007 although it was La Nina year the monsoon was delayed and that was related to the regional patterns of rainfall here sorry the SST here, the SST, the Meridional mode of the SST in the tropical Atlantic seems to be more related to the onset and the seasonal rainfall over West Africa but some of those years are also related to Elina and La Nina but the regional pattern cannot be neglected and without that I think the predictions goes wrong, even this year they had a problem even though it's an Elina year and many models were affecting very dry West African monsoon but it was not so dry mainly because of the regional patterns yes, yes it's mainly because the SST anomalies of Africa were quite warm and that retained the monsoon in that area and then coming to South America here we also have a monsoon but this is again in January, notice that the West African monsoon is in July whereas East African monsoon is in January because it is removed southward during southern summer and similarly for the South American monsoon it's also in January in southern hemisphere summertime and again that is related more to the subtropical high variability in the southern Atlantic compared to Elina, most people think Elina influenced that it's quite possible through the teleconnexions but the subtropical high also cannot be neglected, the trough is very much related to the subtropical high in southern Atlantic now studies are not so much for that reason mainly because the models are not doing well for the Atlantic, most of the models have trouble to find the east-west journal gradient in the tropical Atlantic this black line here is showing you the east-west SST gradient, annual SST gradient as you can see the western side is warm and the eastern side is cold with slight deep in the central Atlantic, most of the model we have given you a few examples but most of the models do it just opposite, western side is warm so most of the model have bias on the eastern side and that affects the monsoon as well as the meridional mode which influence again the monsoon and also the south American monsoon here and the Amazon and that is a big issue and we don't know yet what are the reasons, some people say that it's related to the convection over Amazon, some people say that it's related to the ocean dynamics which is not well captured in those models and my experience says that it's also related to the subtropical high the St. Helena high is very much related to that because most of the model is not capturing that well or they're putting it more towards north and that's why we have warm anomalies on African coast okay to summarize the SN monsoons are interlinked with basin scale climate such as Enso Indian Ocean Dipole, I didn't have time to go into the subtropical Indian Ocean Dipole and there is also a dipole in the southern Indian Ocean and that also influence the monsoon through mascarine high because the high over the southern Indian ocean is also linked to the monsoon through the hardly circulation and the subtropical dipole in the southern Indian ocean also influence that mascarine high and influence the monsoon indirectly and also there is some link I think you are asking this morning there are some studies which shows NAO also could be linked to the Indian monsoon through that mid-luritude and in turn monsoon influences Europe, Arctic, South America and many other places and the interlink seems to be affected by Indian Ocean warming which we saw slightly in the proxy data and the monsoons are affected by MJO and MISO and biosauce so again we need to improve the model predictability for MISO and biosauce model source promises in capturing the source of influences like models are almost doing well to predict Elino Indian Ocean Dipoles but the teleconnections are still not up to the mark so we have to improve the teleconnections and also improve the right place for the connections in the tropical Indian and Pacific oceans the East African monsoon is better simulated by models however they are not so well simulated for the West African and South American monsoon mainly because of the model biases in the tropical Atlantic I will stop there thank you if you have any questions