 The Nolahemisphere is something that I've seen through the week and previous workshops. I thought maybe I put together a bit of the most recent and the history and evolution of the intracisional viability studies in the Southern Hemisphere and in South America. So as I say, I will first point out some non-hemisphere climatological features that we may need to keep in mind when analyzing the Southern Hemisphere circulation patterns on intracisional time scales. Those would be mainly the Southern manual model Antarctic oscillation and then also the Pacific South American pattern. Then we'll discuss a bit about the Rosary wave source and meridional propagation in the Southern Hemisphere with respect to different seasons. And then we'll just focus on South America, mention a bit of the South American monsoon circulation, and then the intracisional viability of South America. So one of the things that I wanted to point out before we start was the seasonality of the Southern Hemisphere jet streams. This is from the ERA Atlas, taken from the 200-electropascal jet level. And then you see that during the Southern Hemisphere summer, which is DJF, we got this, this smaller jet stream mostly over the Southern Atlantic and Southern Indian Oceans. And then moving towards the Southern Hemisphere winter, we also get this very intensive tropical jet in this level, mostly covering the Southern Indian Ocean, Australia and the Eastern Pacific Ocean. And we also get this subpolar wave drain here most to the South. And this feature of the splitting of the wave drains in this region is going to be very important to analyze the propagation of Rosary wave drains there. And you can also see that during the autumn season and spring season, you still get the signal of the subtropical jet stream. So the other feature that I want you to keep in mind is that in the Southern Hemisphere, we get these conversion zones, the South Pacific conversion zone, South Atlantic conversion zone, and also the South Indian conversion zone. They are mostly present during the Southern summer. And here you see the South Atlantic conversion zone using the OLR for the summer. And you see this diagonal band of conversions in the South America, also in the South Pacific zone crossing the Eastern Pacific Ocean. And the South Indian conversion zone is located here. It's a bit more weak and not as intense as the other two conversion zones. And during winter, you see that there is no South Atlantic conversion zone in South America. And you still see some signal of the South Pacific conversion zone that is mostly there throughout the year. And also you can see a conversion zone in the Indian Ocean. So about the Southern Hemisphere circulation patterns in video to highlight it, you first get the, as the leading pattern, the Southern annual mode, also known as Antarctic Oscillation. This is computed as the leading UF of a 700 kPa geopotential height. And you see that there is a negative anomaly of geopotential height in Antarctic region and positive anomalies to the north with three different centers. One is the South Atlantic, another in the South Indian Ocean, another in the Eastern Pacific Ocean. This is known as a positive phase of the Southern annual mode. And it will enhance the Westerlies in this region. So a positive phase, you get an anti-cyclonic anomaly here, and then the Westerlies in the region will be weakened. If you project the daily data over this of this UF, you can get the daily AAO or daily SAM index as it's, sorry, I lost my, as you can see here, and it is, this is for the, around the last three months, and you see that there are some slow variation there, maybe in the intracisimal time scale, that you can also see if you do a power spectrum of the index that you get some peaks of variability around 57 days, 57 days, and also around the 30 or 40 day band of variability. So this can be one important mode of intracisional variability in the Southern Hemisphere. The, the Southern animal is known as seen, is seen across seasons and also across time scales and in the vertical levels. It's mostly a virochropic structure. This is an example for Southern Hemisphere winter. And you, if you perform the UF analysis over the 700, the past eight days, what we've seen in the last slide, you can also do it in upper levels and the lowest stratosphere and you still get this type of annular mode with a bit of differences in intensity of the centers, but you still get this annular mode signal, not only when you do it on unfiltered data, but also when you do it in intracisional band and also in larger intranural time scales. So there has been studies that have related this Southern annular mode to the intracisional variability. In this case, this is a work by Leila Carvalho from 2005. And she studied for the Southern Hemisphere summer the positive and negative phases of the SAM index and they, they performed a composite anomalies, composites using filtrate or well anomalies in the band between 20 and 70 days and they identified positive and negative Southern annular mode phases using this daily index and using the days when the index surpassed one standard deviation for more than four days. So then they defined the onset of some negative phase or positive phase, which is stated here as day zero, and they did perform this like composites. And what they said to found was this evolution of negative or anomalies in the tropics related to the onset of a SAM phase, a negative phase in this case, and a different pattern when they get a positive SAM phase, but also seeing a signal of convection there in the tropical oceans. And they also pointed out in this work that the phases of the Southern annular mode, they changed the latitude along which the cyclones propagate. This is because of this westerly enhancement of weekend, depending on the phase of the SAM pattern. There has also been studies, I think it was from Paul in 2010 that they didn't find a relation between the Southern annular mode and the MJO, but then these other studies said that that was mainly because they used the whole year data together. And in this case, what they did in this study from 2013 is that they related the SEM index with the MJO phases, but separating the analysis in the two seasons of the Southern hemisphere, some extend the winter and then one extended summer. And they saw that here in this figure, see the fraction of days per phase of the positive AO index in red and a negative AO index in black. This is for the Southern winter. And they found that there was a more frequency of days of positive index during the MJO phases, maybe one and two, three, and then there was a less activity of the positive phases during the MJO phases four to eight, which is actually opposite to what they found in the extended summer season when they see that MJO phases six to eight maybe have more frequency of positive AO indexes than this one to four phases. And you see that this relation is opposite and that might be cancelling down the effects if you take the whole season, the whole year together. One other thing that they found is that there was a significant contribution of MJO to the SEM tendency, which would be the change over the day of the index on the intracisional time scale and especially for strong MJO episodes. So the next two circulation patterns in the Southern Hemisphere is this one were mentioned before, are the PSA patterns or Pacific South American patterns. They are the UF2 and 3 of circulation. In this case, they are taking using the 200 kPa string function. This is the work of Mohan Higgins in 1998 for offshore winter. And you see that these patterns are mostly wave frames with wave number three structure that they are around the South Pacific Ocean and then move towards the northeast in South America. And during winter, there's a particular feature that you get this also subtropical signal, which is opposite at the same longitude for the subpolar region. They also say that these patterns were found when you take the low frequency band from 10 days on larger periods and also when restricting it to the intracisional band. So they have been related also in terranial time scales to answer features and the intracisional time scale in this case, they analyzed it and related to tropical convection. They also pointed out that the main periods are around 36 to 40 days, but they also seen around 17 days in this type of patterns. And they also show the classical evolution of these wave frames that this propagation will be coming from a positive PSA1, then a positive PSA2, then a negative PSA1. So they show it like a propagation of the waves. A couple of years later in this study of 2001, they computed the PSA but pulling all systems together. And this would be the EOF using also the string function in 200 opascals. And in this case, they took only the DJF season of the principal component associated to this pattern and they perform a composite using the intracisional filter OLR and the 200 opascal string function. So in this case, they define the onset of a PSA event using the PC1 and when the PC1 surpasses the 1.2 standard deviations or the net it was below negative 1.2 standard deviations. So here in this composite, this would be for the OLR and this for the string function. The onset of the event would be around this lags. This is from day minus two to day plus two. You can see here in the string function that it should be similar to this PSA1 pattern with positive anomalies here in the region of Australia, the negative positive, sorry, anti-cyclonic anomalies here, then cyclonic, anti-cyclonic, and cyclonic anomalies here. So this should be the circulation and this type of pattern you see that they affect not only the South Asian South America region but also further to the North. And when they perform like composites, they also found that there was a region of enhanced convection in the tropical oceans that was moving from the Indian oceans towards the Pacific oceans related to the evolution of this pattern. So they linked in some areas of this pattern to tropical convection. And particularly I see that the equator is here in this figure and then here in this figure. So it could be related that the convection here through this anti-cyclonic circulation at the same longitude and then the Pacific South American weight train extended to South America. So we've already seen quite a bit about this in the lectures about the Rossby wave source. And as the lectures pointed out, when you divide the source, the source term of the Rossby waves into these diversions component and the abjection components by the divergent wind, then you can extend this Rossby wave source into the extra tropics when the propagation is more, when the propagation extends and it's easy for the wave to propagate. So this is the term that I was talking about. This would be the abjection by the divergent wind of the absolute vorticity and what it is divided between the mean state and the perturbations. And in this case, this was worked, I think, from Greenman, I think, Silva Diaz in 1995, I was recalled here in this other study. And what they did was they computed the source term of the Rossby wave source when they only considered conversions and diversions in the tropics from the diversions term only. In that case, you see that the Rossby wave source is most located near the tropics. But then when they use this whole expression for the Rossby wave source, you see that the Rossby waves are extended to the extra tropic regions when they can also propagate. So this is a work from 2011 of Simiso and Cavalcanti and they computed the averages of in each season for the Rossby wave source term, in this case taking less the diversion of the product between the divergent wind and the absolute vorticity. And so that allowed us to see the main mean Rossby wave sources in the southern hemisphere across the seasons. Focusing first in South America, you see that here in the SACS region or the South Atlantic Conversion South region is a region of Rossby wave source during the summer. And this region has been related to exciting Rossby wave trends that move towards the African region and then modulate precipitation there in interest on all time scales. I won't be talking about that in my lectures, but there were several studies relating convection here to impacts of precipitation in the African region. You can see that there is no wave source in the South Atlantic Conversion South in winter when it's not there, then it's really reduced during the autumn and spring. I also see that the South Pacific Conversion South region might be a region of generation of Rossby wave trends during the whole seasons. Okay, but we don't only need a source of the Rossby wave, but we also need a proper condition for them to propagate. So in this case, what I'm showing is again the sun and wind mean for each of the four seasons and also the gradient of absolute vorticity as using the barotropic theory of three waves. Here you have the total stationary Rossby wave number. That stationary if you consider that no, there's no velocity of the waves. And then if you, for the wave to propagate, this should be greater than zero and particularly this should be, this coefficient should be positive. So in these figures, we get this, we see that mostly the wind is positive here. So here's the case of violet values, purple values are all positive. But then you have some regions mostly in winter when you get a negative, maybe the gradient of absolute vorticity in the atmosphere and related to this is picking up the jet region. So propagation can be produced across this region in winter and it's still there during the autumn and spring season, but really reduced. So this is another important feature for the sun and hemisphere winter about the propagation of the Rossby wave trends in the region. This is also a word from 1995 that Nicholas has given us a really updated version using the influence functions that are used to detect where the diversion signal in the winds may be influencing a certain region. In this case, it was a barotropic model and using a target point in the South Atlantic conversion zone region, they found that the region where it could be exciting those wave trends might be coming from the central Pacific region or ESPCC region slightly displaced to the east. So he gave a lot of updates in the previous talk. So following this circulation characterization of the solar hemisphere, now we're going to focus in South America. This is the continent and the colors show that the population density as they show before in the first talk. And so this will be the South East and South America region that we mentioned in the future. The South Atlantic conversion zone region and also the Northeast Brazil region that we also have some talks in the previous days. So the main countries involved here are Argentina, where I came from. So here would be Buenos Aires, which is my city. Then Uruguay, Brazil, Paraguay and Bolivia. And why is this important? Because in this South East and South America region, there is the major river basin, which is La Plata River basin. This is the La Plata River here. And not only is this one of the most highly populated region in eastern South America, but it's also the largest food and crop producers in the region. Agriculture, livestock, fishing are also important activities here. And also they have 75 dams for hydropower generation in all the rivers contributing to this basin. So not only analyzing the positional variability of rainfall in this region is important, but also they are really pushing us to analyze the subsistional forecast for the region and monitoring also not only prediction, but also monitoring tools for the intracisional variability of precipitation here. So the rainy season is mainly modulated by the South America monsoon system. Here you can see the with the winter in the middle, the vast showing the precipitation multi-cycle in South America. This figure is taken from a region around here. And in this region, you can see precipitation covering this broadband in the tropical South American region. And as you can see, there is mostly a rainy season between October or November and a March or April. So here you see the maximum precipitation centred in southern hemisphere summer. And you can also see that the variability here moving more closer to the equator, you see from October to April, that is the maximum rainfall virality time. And just to illustrate this, here is an animation of the OLR and 200 kPa streamlines showing the evolution across the year of convection. So you start in the spring and moving into summer, you get this convection move towards the center of the south hemisphere continent with this sort of anti-conversion sound here. It's also characterized by an anti-cyclonic circulation that is here seen over Bolivia is here, that moves again with this enhanced convection during summer. And then during the summer hemisphere winter, this convection moves to the northern hemisphere. So the main features of the South American monsoon system, here you have the DJF precipitation and low-level winds and the upper-level winds with precipitation that's taken from the trim for the DJF season and the JGA season, summer and winter. And you see here the South Atlantic conversion sounds showed by the precipitation. And in the upper-level winds, you can also see this anti-cyclonic circulation that was mentioned is called the Bolivian high associated with this pattern. And you also see here the Northeast Brazil low or the Northeast Brazil drop, that one of the main features of the South American monsoon system. The main driver of this monsoon system is the differential heating between the South American and the Atlantic oceans. And you also have the Andes College here at the west portion of the continent that always also contributes to this monsoon system. So with all that in mind, I'll start discussing a bit about the intracisional viability in South America. This was one of the first studies by Noguespegel and Mohr in 1997. And in this case, they applied a rotated EOF analysis for intracisional filtrate over anomalies. In this case, they can intracisional band as 10 to 90 days. And in this number five EOF for the Southern Hemisphere summer, they found this dipole between the viability in the South Atlantic conversion sound region and the South Eastern South America region. And also using the principal component as the daily time series, they perform composites that relate these solar anomalies here in the actually to the EOF five to tropical convection. So this was one of the first studies pointed that out. It was mentioned previously, this study by Leib and others in 1999 for the Southern Hemisphere summer. In this case, they analyzed the sub monthly viability taken from two to 30 days. And they perform also composites using the SACS activity taken from the OLR. And what they found is that for in the evolution of this SACS region, here you can see from today before a wave train coming from the extra tropics towards the North East region in South America. And in the leading edge of this cyclonic circulation, then you get this enhanced convection that points out to the SACS activity. So this would be for the zero when convection is mostly enhanced here. The cyclonic circulation is most intense and the wave train propagates to the North. In this case, they found that the disturbances coming from the extra tropics are molecular and barotropic in the West of South America by the westward with height in the region close to the SACS. And when they perform composites using the Hohle Hemisphere, they could see that there was some path of frosty wave energy coming from the mid latitudes here is the New Zealand region towards South America. So they might be affecting the mid latitudes generating this SACS activity during Southern Hemisphere summer. Most recent study by Van Der Beel et al. in 2015 that was also mentioned before. In this case, they studied the time scale of periods below 20 days and they perform a new analysis in this region covering mostly the SACS region. They found that the leading pattern was otherwise dipole between the South American region and the SACS region. In this case, you have the Ovala anomalies shaded, the vector wind and also this would point the contours are vorticity. And what they found out in this study when they performed this light composite also was this extra tropical wave trains coming from the Southwest Pacific towards South America. And what they wanted to study was how does this authentic conversion zone diagonal features form. And what they found was that using the Rossby wave barotropic dynamics and ray tracing techniques, they can find the appropriate deformation of a center of vorticity here in the Western South Pacific Ocean. And then if they trace along all these lines, they could form these elongated centers within West Southeast still. So they could attribute this deformation of the wave train toward the Northeast. And they finally conclude this conceptual model when the vector ratio is almost circular in the South Pacific Ocean and then they start to get this major elongation of West Southeast still as they advance towards the Northeast. And also in the leading edge of this draft, you get the convection associated with the SACS, which is something similar to what Lee Mann had found before. So for some hemisphere summer, then this conceptual model focusing mostly in South America would be that we can have two phases of this dipole pattern, one phase where we have a weakened tax and enhanced precipitation in the South American region. As we focus mostly here, we will call this a positive phase of the pattern. So one precipitation is enhanced in the South American region at the leading edge of this draft that is located in the southern tip of the continent. And then you have a weakened tax also with characterization of an intensified low-level jet coming from here towards the central region of Argentina. And this type of pattern has been associated with being delivered for events here at the South Pacific. And as opposed to that, we have a negative phase of the pattern when the start is the one that is in the leading edge of the draft that is located in the South Pacific of the South American region and then here in the South American region. In this case, this type of pattern was related to the higher frequency of deep waves and extreme daily temperature events. And the mechanism that was proposed by the president of the SACS here in the SACS region will produce compensatory tax here in the South tropical region. So it was coming from outside. So this type of heating produced by the compensatory subsidence here and the clear skies would produce when it's persistent the heat waves here in the region of the eastern and northern Argentina. So when we moved to the southern hemisphere winter that was not as studied as the southern hemisphere summer by analogy, we tried to also analyze the this intracisional variability of all our during winter as a proxy to the this intracisional variability of precipitation. And we took the first of the of the analysis in this region. And what we got in this case, you can see an intense dipole, but only one intense center following this region in the distance of America, northern Paraguay and southern Brazil. And we could relate that this center of activity was it had main periods of variability between 17 and 30 to 40 days, which was similar to the BSA patterns. And also we could relate this region as the region where the cold fronts that they come from the southwestern region, like from this region, they advance towards here, and then they tend to become stationary in this region. So that also can be affecting the variability of this region. We then perform like a linear lag regressions using the principal component associated to this pattern to analyze how the convection involved the tropical convection evolves in this season and also the southern hemisphere circulation. So these are not these lag regression are computed from day zero backwards up to day 10 I'm showing. And then on day zero what you see is this is upper level geopotential height a cyclonic anomaly here in the northern Argentina, UI and southern Brazil, which would be a bit a bit upstream of this convection center that you could locate here in associated to the first TOF, which would be this one. And then if you see upstream, then you can see these wavelengths coming from the extra tropics and also from the subpolar regions, which are similar to the winter BSA patterns that I've shown before. So if you are six days before or eight days before, you can see also this tropical wave train in the opposite phase of the subpolar wave train, which is divided in this region because of the splitting of the jet. So those are just waveguides in the winter, and then you get this propagation toward the northeastern South America. As you can see, there's not a clear signal of the Madem Julial activity or the tropical convective activity here in the tropics, as it's not the, this is June, July, August, it's not the main season of viability related in the solar hemisphere. So if you want to look at the full seasonal cycle of this viability, here I'm showing in the contours the mean OLR for the season. So here is for DJF, you see the strongest contours showing the mean position of the South Atlantic conversion zone. Then you can see it here in June, July, August, and in this transition season since September, October, November, it's coming from the north. And then in during the Austral Spring, it's moving toward the Nova Hemisphere. And in shaded, you can see the standard deviation of the filter in transitional filter OLR anomalies. And you can see that during summer, even though the mean viability, the mean sex position is here, the viability is located a bit to the north of that region and also in location here in the South East and South America. The viability is less intense during autumn and spring and a bit also during spring season. But you can see also the location of the higher viability in the main region of the UF here. And also during March, April, May, you can see quite extended here in the subtropical region. So if we perform the first UF of this intracinational filter OLR anomalies, you can see that they're mostly dipoles during the DJF autumn and spring seasons with seasonal differences there. We are taking the 10 to 90 days viability. And during winter, then you can see only one center of action located here, as we pointed out before. We call this the seasonal intracinational patterns. We could relate this to the precipitation in the South East and South America region in the following way using the first principle components. So focus here first. This would be called the SIS index or it's the standardized PC1 index following DCOF. So when it's positive, we name it like a wet phase of the pattern from the southeastern South America point of view. So a positive index would mean that you have a negative OLR anomalies here and positive in the SACs. So the SACs would be inhibited in summer and then the convection will be enhanced more to the south. And the opposite in the dry phase, the dry phase would be when the convection is enhancing the region of more variability associated to the South Atlantic conversion zone and then it would be inhibited in the SISA region. So we took a couple of grid points in the center of action of the South East and South America region for each of the seasons. And I'm sorry that these figures are in Spanish, but you can still see the point I guess. This will be the frequency and this is the duration in days of consecutive days of precipitation observed in the region here pointed by the cross. So you get two days of consecutive rainfall above the 75th percentile in the region, three days, four days, five days and up to six days. And what we try to associate this occurrence of wet spells to the sign of this index that shows the activity of these patterns. What we can mostly see was that as these wet spells last longer, then they all tend to occur in the wet phase of this pattern. And this was more evident in the intense wet spells. So this is what it leads us to use this index that monitors these patterns to analyze the intracisional variability in the rainfall in the region. So the take home messages of all this talk would be that the leading patterns intensify the southern hemisphere circulation and which have an influence on intracisional time scales as the southern annual mode on one hand. And then we have the two Pacific South American patterns that have this wave train like features that propagate in the South Pacific towards South America. Then the meridian appropriation condition for the rosby wave trains change across the seasons and the mostly different in the austral winter when we have this forbidden region for propagation around the Australian New Zealand region associated to the speed of the wave, the jet, and then the speed of the wave trains there. The most the biggest driver of South American precipitation is the South American monsoon system which may features of the South Atlantic conversion zone and this upper level Bolivian high in upper levels. Then the intracisional variability of convection rainfall in South America is associated with the dipole pattern in summer or the wet season and then the monopole in winter. The activity of these patterns is related to the propagation of rosby wave train across the Pacific. We show different seasonal features and mostly during winter we've seen that they relate to the PSA patterns. And it was the activity of these patterns that could be related to the currents of intense wet spells in the South Asian South America region and that is why we're going to be monitoring this activity to to infer about the possibility of occurrence of these wet spells. So I left after a couple references of all the points that I mentioned. So thank you for your time and your invitation here to the HDP mostly to Fred and David that organized this. Thank you.