 I'm delighted to introduce another talk by Shui. Shui also gave a lecture at last week's Colloquium. Thank you so much. And today she's going to talk about can rain and wind from MJL help starting El Nino. And this is work she has done together with Jaglyn. Oh, I missed it. And who was one of the Colloquium participants? Shui, welcome. And thanks for your talk. Well, thank you, Judas. And thank you, Anish. And Judas, it has been a great program and workshop. And thank you for the invitation. So we have opportunity to discuss a little more in-depth about this particular work. And mostly is Jaglyn's work of her PhD thesis. This just part of a PhD thesis, but she's going to be continue on quite this. And a lot of these results are still kind of in the early stage, but the goal in this particular study is really try to understand the physical processes and especially the multi-scale characteristics that from the rain and wind from very high-frequency phenomena. And that organized it into the MGO timescale, which is intracisional and upscaling to Enso timescale. So without further ado, let me just start this process. I'm going to turn off the video just to save the bandwidth, see if I can order screen. So somehow, okay, all right. So what is MGO, right? So we often wanted to check how simple can we get? So this is kind of a thing that both lots of the current website put up for explaining this. So as you can see this person says, well, it's rain tomorrow, MGO is in phase one. And then they say, are you sure? So let's check, blah, blah, blah. So, you know, you can see the MGO getting into this sort of a common space of science. I'm having a hard time to advance my, okay. What is Enso? This is the NOAA's website and talking about Enso. He's a suite, it's another Oninu. And Oninu is a weather pattern that occurs in the West Pacific Ocean, but it is so big that it affect global weather all over the world. So there's a common theme here. These two cartoons link something that we are talking about this phenomenon, that's rain. So somehow these rains seem to be a common theme in this, but we haven't really studied what's the rain in the air sea coupled system that contribute to this multi-scale air sea interaction that actually help transfer scale from the high frequency to low frequency. But seriously, so this is kind of a things you can sort of look up and has been showing many times before. So MGO is this East War propagating system with strong westerly windburst. And it's on the intracesional time scale. It's a 30 to 90 days. And then if you look at Enso again, you see these rains that are from West Pacific toward the Central Pacific, eventually moving on to the West, the East Pacific. And during this much longer time scales in annual two to seven years, but it certainly have this ocean basin scale property of rain, SST and the upper ocean thermal client and so on and so on. So MGO has not been drawn this type of things on the ocean counter apart until I saw this figure on a website that it was drawn by the, I think it's a national weather surfacing boulder. And I have to say that I was really impressed by this cartoon and I was to find it also who the actual person drawn this. But this is a depiction of MGO in the tropical Pacific ocean. And you can sort of see the way they draw based on MGO active phase, surprise phase and ahead of MGO. So the important things I want to draw your attention is also the ocean part by the upper ocean, they're looking at temperature anomaly. So looking at a warm ocean anomaly underneath MGO. And the same time they're drawing these propagation of a Kevin wave and so on and so on. There's quite a lot to it. But the important thing is really connection to this part that MGO connection to INSO and this is the Minio 3 and 4. But the question in this diagram, obviously this is a very nice depiction. But in fact, these phenomena do not occur simultaneously as this thing is drawing. In fact, MGO when you see the ocean warming, MGO already passed to its active phase. So this is where this study is examining the period time when the MGO is active or was specific. How does in time that influence the upper ocean warming that eventually pushing quite a bit of warm water toward the central Pacific. So keep that in mind and you can see the currents that they're drawing there. And I will address this because this part is actually different than we find recently from both observations and the modeling work. So this is the way that we track MGO because in order to study the detailed MGO impact, we need to look at the MGO rain which I presented this in the lecture and just repeating this, that we are tracking the precipitation associated with winds, surface winds. So clearly there's enhanced the precipitation associated with MGO and also wedged winds. These have really sort of a strong impact on the ocean part. And then produce something very interesting that kind of induce this multi-scale sea interaction process. So using this method, this is based on observations. So we are looking at the observational data to see how much of this MGO in observations you can associate with the insole or this outside of a oninu in the central Pacific. So in this paper, Jacqueline and I put together for using over 20 years of data, well, first we kind of looking at particular each events. So this is to the left corner here. Can you see my cursor? Yeah, we can see each. Right, so you can see the multi-MGO event that this particular year 2018 that associated with strong winds and it's this warming toward the central Pacific. So basically this, we call it the warm pool eastward extension is a coincide with this turn of the oninu to oninu phase. So this is where we refer to as onset. So looking at this warming, maximum warming occurs after MGO. So that's really a key factor you should keep in mind. Then if you look at the 20 years data that this 20 years and then you can see the six oninu event, right? It's all preceded by a very strong and a persistent MGO event marked by this, right? We've done statistics in this particular paper and the really convinced that MGO has quite to do with this eastward pushing of the warm pool, which is this magenta color and that's the actual SST compared to climatology. It really is a significant. So a key finding in that, which remember I mentioned the timing of this. So if you look at MGO induce the warming spatial space, then during the MGO, there's kind of warming there because certain process I'll get to a second. And then you will see the central Pacific warming is the largest. If you subtract the two, you get to see the projection of the MGO warming that getting into the in, so the oninu three and four space. So that really tells you the post-MGO warming is actually play a central role to this. So just quickly as review, the MGO induce our pro-ocean dynamics, both introduce the westerly winters, induce the cabin wave, which has been documented this study a long time ago. And also a long time ago during total core, we actually observed MGO induce precipitation and wind can actually induce a pro-ocean barrier layer that actually kind of blocking the thermal upwelling and the wind influence to the up-ocean that help the warming and that you get the maximized surface solar heating during this phase. So this is all well-known effect. So then we start using a model, couple of model to examine the physical processes. So what is going on in terms of MGO and warming, right? So this particular model that we have coupled the atom sphere, which is a wharf and the ocean as ocean, it's a high calm circulation model. That's our model domain. We have done experiment. I don't want to go through any of the details so you can read these later on. And we assimilated this over many months of this year up to several MGO event up to the onsite of the ENSO. In this particular study, we actually conduct experiment. We want to know what's the influence of the precipitation and coupling to salinity that have impact on this particular mechanism that we're talking about here. So just quickly, if you look these period of time that our couple model simulation of ocean temperature and the salinity, you will find this warm pool. This is the temperature. The warm pool has this eastward propagating properties and is associated with the cabin wave usually induce this steepening of thermal climb. And if you look at the salinity is clearly showing the fresh pool propagating eastward. And this fresh pool actually contributed quite a bit to this barrier formation as well. So again, there's a lot of details on the figure. So not to worry too much except to say that these colors now is looking at a difference between the control simulation and the one we removed the precipitation and the vibration coupling. So clearly the impact of a rain has a very large impact on the salinity which means the fresh water and warming of the ocean. And it's very clear physical mechanism that tells us that the fresh water pool is definitely play a central role here. Then if you follow a particular NGO event in the middle part that you will see this very strong fresh water pool propagating eastward with a positive velocity which means this water itself is moving against wind. This is a new result because prior to this we haven't realized that this big fresh water pool is propagating against the wind which means this is really driven by uproaching dynamics. And then it also accompanied with these very strong warming, the eastward propagating warming. So in order to really see this multi-scale process that you will have to look at a detailed process in terms of we separate the west Pacific, central Pacific and east Pacific. So not worry about too much about the details except to say if you look at the temperature the red is the one from a control simulation minus one without the salinity coupling. And then you can see the one in control simulation with fresh water definitely have this warming effect and the diurnal cycle heating during the warming process that actually have all these large warming kind of associated with this shallower of the mix layer, shallower of the barrier layer, ocean barrier layer. And this warming is actually under these cities not under MGO, it's really post-MGO. So if you look at the central Pacific, east Pacific that warming definitely occurs that the MGO didn't reach this far but it's through the uproaching process itself. So I don't think that, huh? You can wrap up in two minutes or so. Sure, I hope so. Let's not worry about this. All I want to tell you that we did a detailed budget calculation try to figure out what's driving this occurrence, westerly currents against the wind, right? So basically Yakhlin has did all the calculations. So we will find this one particular term in the uproach that drives the ocean current is a pressure gradient. Okay, so these each terms that are displayed here but I want to come to this particular slides to show you that. So first of all, we want to check is the model actually be validated by observations? Sure enough, we have a particular moring at 165. So this is a time series during this event. So basically, as you can see we don't have detailed measurements of freshwater but enough to tell us the suppression over this period of time and warming during this period of time. And very importantly, that there is observed jet and this particular jet has very strong speed this as a centimeter per second which is very similar with what model showing and model shows you the mechanism that is really driving through, not through wind stress or anything else but the pressure gradient of the freshwater versus the salty water in that region. So basically this is come to the summary of that. So the things I've mentioned before so from the Central Pacific, the West Pacific we have these kind of a physical mechanism of rain in those freshwater. And then this thing will propagate eastward and during this time, the MGO kind of subsided the precipitation part but then under the easterly wind this water part become very much on its own moving eastward and driven by ocean, upper ocean dynamics. So during this time, as soon as we're moving the SSD gradient toward the Central Pacific the treat winds start relaxed. And then at a later stage after months, several MGO events you will see this, the warming over the region where the annual started getting onset. So with that and some of the results are summarizing some manuscripts that we've been writing. So in summary, I guess we answered that question we did convince ourselves the rain and winds from that MGO can help start a new event. So this, the coupling precipitation and the evaporation and salinity it really play a very, very important role for Earth's system modeling people that I think you really want to make sure this part it's resolved in the model then in combination of the many things that we can I guess I'll end this last show, right? I don't know, say sorry. Then the combination of high fruits, currency phenomena and then our portion dynamics like deepening of a mixed layer and the shoaling of the barrier layer all play a very important role after several weeks and then several events can accumulate over months to leading to the warming. So if we can do this well then we believe Angio is a source of predictability can really bridging the weather and climate from the high frequency to low frequency phenomena. So Yaqui is going to be doing her future work using CSM2 to looking at a multi-year event. So thank you, that's all I have. Thanks very much, Shui. Thank you for this comprehensive talk. I learned something new each time I listened to it. So we have the first question from Pemi. Pemi, go ahead and unmute yourself. Yeah, Shui, thank you very much for the great talk. My question is about the MGO dipole structure. So the MGO in a normal sense it has also active and the suppressed phase and suppressed phase may have the opposite wind direction and rain. So how does the suppressed phase play a role in this mechanism? So that's a good question. So if you can think of MGO kind of always like preceded by a suppressed phase and also after MGO is a suppressed phase. So in fact, during that suppressed phase it's the most warming occur. So we call the post-MGO warming. And then that process is describing this particular study. So MGO suppressed phase is very important in that way for Central Pacific, the West Pacific, Central Pacific because that's time when we have a large warming and the post-MGO suppressed phase, the freshwater inject into ocean can stay alive by itself for another several weeks and two months. So I do think that it's a part of this whole dynamic system. It's a part of the air-sint action process that it has not been examined before. So certainly has this important role. Thank you. Thanks. Any other questions? So I had one. Sure. Thanks Shui, a great talk. I was wondering about the 2014-15 failed El Nino versus 2015-16 where we had the big El Nino event and was there this pre-precipitation of operation salinity coupling that actually happened in 2015-16 and did not happen in 2014-15 when we had the failed El Nino? I guess how important is this event for like the big El Nino events like the 97, 98 and the 82, 83? Yeah, that's an excellent question. And I don't think these sort of a totality of the in-sole El Nino events can be explained by one particular phenomenon either so basically if you can think of an in-sole itself is a dynamic system can exist on its own independently of MGO, MGO also exists, right? So independently they are interacting in the real world as we heard that sometime model having problem is how to superimpose of the two dynamic system. So I do believe a lot of times we have a failed MGO in-sole or not perhaps have something to do with this trigger mechanism. This is a large scale, maybe ready to go but we're lacking of a trigger mechanism and we sort of start looking at the high frequency phenomena MGO like several months before the in-sole onsite they do have a different frequency and intensity. So indication is that this trigger mechanism is very important and how that two dynamic system interacting in time and space and I think it's important and certainly hoping that community pay attention to we can use much more sort of longer time scale to look at the entire two decades and see what happens. Thanks. Thank you. Thanks so much, Shui. So now we're gonna go to