Jin-Yi Yu: In this talk, I'm going to show that the transition complexity in El Nino is different from your transition compress the in that arena.
Jin-Yi Yu: And we'll explain what's the reason for this difference and how they may change in the future, my calls so away from also from UC Irvine.
Jin-Yi Yu: So he had his termination complexity. We talked about is referring to the fact that there's three different event to event transmission pattern that can be observed.
Jin-Yi Yu: The first part in his secret transition where an El Nino is followed by Latino or Latina is followed by El Nino
Jin-Yi Yu: The second pattern is the episodic television pattern where the El Nino La Nina is preceded by a new so condition in the previous years.
Jin-Yi Yu: And the search donation pattern is the multi year tradition pattern where ninos followed by another El Nino or La Nina is followed by another man. He now.
Jin-Yi Yu: He's going to get the observation event during the 1948 to 2016 we noticed that the transmission pattern in the arena in La Nina ability
Jin-Yi Yu: For the El Nino. It is mostly dominated by episodic followed by cyclic tradition and there's a very small percentage of El Nino event showing this multi years evolution pattern.
Jin-Yi Yu: However, in contrast, we noticed that the law, not even observed during the same period of time is mostly dominated
Jin-Yi Yu: By this multi transmission pattern 42% of Los lamanna even is showing this Danny not followed by Donna. And then secondly, and this amongst episodic so this tradition.
Jin-Yi Yu: Tradition compress the is completely reverse between El Nino and now Nina blue here to become a minimum and multi year here minima to become maximum in La Nina.
Jin-Yi Yu: So the question we want to ask is why they are more quality Ronnie, not even then multi El Nino event you need observation. What is the reason for this El Nino now Nina a symmetric. So in our
Jin-Yi Yu: 2016 1718 paper we already find out that these which transmission pattern can occur is actually controlled by how the El Nino and 99 even
Jin-Yi Yu: Trigger by the same mechanism. So if the alien on Amina even is onset by the tropical Pacific process, such as those that described by the charge discharge fascinator theory we noticed that
Jin-Yi Yu: The El Nino upset by this mechanism is preceded by an army knife in the previous year.
Jin-Yi Yu: And now I mean I'm said by such a tropical Pacific process is preceded by a Nino condition in the previous years. So the tropical I'm saying mechanism. Always try to produce a secret.
Jin-Yi Yu: And so transmission make a Nino fellow Nina. Nina, followed by arena, instead of if we El Nino nanny event is on set, or triggered by a subtropical Pacific process. Then we noticed that the El Nino I'm set by such a
Jin-Yi Yu: Subtropical process can be perceived by El Nino to become to put this movie alien or Mina can be perceived by an add on enough to put this multi year
Jin-Yi Yu: Now, Nina. So the subtropical Pacific I'm same mechanism is a key sauce to produce more the El Nino a multi year now. Nina and human speaker, which I did an experiment detail.
Jin-Yi Yu: How this feature show, but basically the speaker. Tell us about 20 to 30% of El Nino event that is upset by the subtropical passivity process, we noticed that
Jin-Yi Yu: About 20 or 30% of them show the multi years evolution pattern, but for the last for the new not even that triggered by these subtropical I'm safe mechanism we notice that
Jin-Yi Yu: Close to 40 or 50% of those events were showing a multi year now. Nina evolution pattern. So this result here is that the
Jin-Yi Yu: More multi and Amina demo mode El Nino this a symmetry actually can be extreme if we focus on this subtropical Pacific. I'm saying mechanism. So now let's look at the subtropical Pacific I'm semiconductor to see what how this mechanism operate.
Jin-Yi Yu: So here are we showing this series of a temperature when I normally associate with this multi with this subtropical answer mechanism in this path and is Hopkin by performing this multi variable.
Jin-Yi Yu: Analysis and this E F innocence, tell us that the key feature of these subtropical answer mechanism is that this mechanism is
Jin-Yi Yu: Is associated with these trailing anomaly in the north eastern Pacific region. So what happened is that when we have these trailing and normally
Jin-Yi Yu: That is against the penguin tree when it is particular phase of the subtropical on same mechanism, then this window nominees going to reduce wind speed in the region.
Jin-Yi Yu: And we use wind speeds going to reduce survey. He frogs and our warm up the SST right outside is North North American coast and this
Jin-Yi Yu: Initial warming is going to compare me excited Commission on the sodden end of this wall and no money and this
Jin-Yi Yu: Anomalous big commercial is against is going to accompany with the new center of this trailing anomaly and this new trailer nominee is going to reduce he flashed
Jin-Yi Yu: On the southern end of this initial SST nominee. And again, we're going to form a new SSD anomaly. To the south western corner of this initial
Jin-Yi Yu: SSP warming. And so these when the population SSD feedback. We can argue that this woman nominee right outside the North American coast will continue to extend Southwest war and eventually reach the equatorial region to treat
Jin-Yi Yu: El Nino or an event event. And that's why we call this process is subtropical Pacific answer mechanism so
Jin-Yi Yu: In this this discussion, the most important element of this subtropical same mechanism is that we need to produce this tray when anomaly. So we need to focus on how those tray. When I normally get per deal can be produced.
Jin-Yi Yu: And we find out that there are three way to produce these trembling I nominate to turn on this subtropical Pacific on same mechanism. The first one is well known and these it is
Jin-Yi Yu: Most of most of the, we can see that up this traveling or nominee is associated with the uttermost spray called disturbance in the subtropical
Jin-Yi Yu: Extra tropical region, and we actually believe that this is mostly related to the North Pacific oxidation and this MPL is relate to other face.
Jin-Yi Yu: variation between our new symbol and subtropical high when these notes perceive as an agent happen. For example, in this particular phase, we have a weakened subtropical high we produce a psychotic second anomaly here this iconic anomaly is going to produce
Jin-Yi Yu: One anomaly that try to we kind of travel and and and then we'll turn on these when the population SSD feedback to produce an El Nino event.
Jin-Yi Yu: And this area, not even produced by this process in the previous year he was only relate to most personalization, which is not
Jin-Yi Yu: Nina. Nina. So this solution patent is episodic and so transmission pattern and this year and pattern also tell us that this trailer and Noemi may be related to this call SST or no me in this
Jin-Yi Yu: Cold can region. So what happened is that if we have a caller normally if this call Noemi can produce anomalous cooling. But for some reason, then this anomalous coding is going to excite to tire response and pull the northwestern corner of his Cooley, we should produce
Jin-Yi Yu: Trey when I normally similar to this one, we see here. And so this in this particular phase. If we have an army and I in the eastern Pacific region is going to come on this.
Jin-Yi Yu: Past the face of subtropical Pacific on some mechanism sewer killed her response.
Jin-Yi Yu: In this positive face of these tropical and semi colon is going to give rise to an El Nino in the second years so through this process. This subtropical Pacific mechanism.
Jin-Yi Yu: Allow Davina to be followed by El Nino or alien or to be followed by running. So we will produce the satanic secret and so transmission
Jin-Yi Yu: And this part and also tell us if we have SST anomaly in the Central Pacific
Jin-Yi Yu: For example, in this particular example, if we have warming here because we have strong West anyway in this region. So, to carry response will be more immediately to the north of is
Jin-Yi Yu: warming or cooling. And so now we're also producer when a nominee, similar to the trailing anomaly. We need to activate this subtropical answer mechanism. But in this case, if we have what a nominee here is going to produce
Jin-Yi Yu: Psychotic when a nominee that will turn on the positive face or sub topic on some mechanism. And in the second year. The next year.
Jin-Yi Yu: This room is going to come down to produce the second El Nino. So now, a lot. El Nino to be followed by El Nino nanny.
Jin-Yi Yu: To be followed by now. Nina to produce multi year and so transition
Jin-Yi Yu: So there's three ways to turn on the subtropical on some occasion. Explain why subtropical pursue answer mechanism is particularly important to control the transmission complexity because these different families.
Jin-Yi Yu: Charge this chatting mechanism which all tend to produce the SEC separate transmission pattern. This subtropical answer mechanism can produce
Jin-Yi Yu: All three episodic psychotic and multi year transmission pattern. So now let's focus on this multi transmission pattern on this relate to this Central Pacific region.
Jin-Yi Yu: So as we explained early on that, if we are warming here. We're going to produce
Jin-Yi Yu: Filter response. Turn on the positives subtropical on some mechanism.
Jin-Yi Yu: And in the following season. This woman is can extend Southwest into equator to produce the second
Jin-Yi Yu: Woman and a multi year seminary, we are calling here. We're going to produce the strengths and traveling and produce the cooling and it's cold. It's cold coming down in the second year produce a second will
Jin-Yi Yu: Quoting event. So now the question is why nature choose to produce more more de El Nino them multi year Amina so to explain
Jin-Yi Yu: This question to answer this question, we need to focus on our original argument argument is that in order for this woman according in the Central Pacific to cannot activate this subtropical
Jin-Yi Yu: Same mechanism. This woman, including has to be able to excite to impact the deep compassion in this region to produce anomalous who cooling or warming to produce killed her response.
Jin-Yi Yu: So the key thing is that warming and cooling in this region has to be able to affect the deep compassion.
Jin-Yi Yu: So now we know that the threshold value to produce a deep compassion is at a present a comment is 28 degrees east
Jin-Yi Yu: So you look at the background temperature in this Central Pacific region, we realized that the Central Pacific region is located on the
Jin-Yi Yu: Western Eastern Asia of this into personal home pool where the temperature is just slightly above the 28 degrees. See here.
Jin-Yi Yu: So this slide is about 28 degrees. He is the reason why the nature this mechanism oil produce more multi running and then multi year El Nino. Let me explain why. How this walk
Jin-Yi Yu: So basically, because the temperature is just slightly different temperature is slightly above
Jin-Yi Yu: The greasy and that we already in a normal condition we already produced the conversion. So now if we put a El Nino condition warming in this sense of passive
Jin-Yi Yu: Past. This woman is going to increase the commercial and produce positive anomalous roaming
Jin-Yi Yu: But we know that most of the arrow, not in a Central Pacific tend to be weak El Nino. So this anomalous heating, we introduced introduced in the region is going to be small.
Jin-Yi Yu: However, in the same location we introduce a La Nina which you are Clinton, the temperature to below these thresholds 28 degrees C. And that means banner with any
Jin-Yi Yu: Intensity is easy can shut down this deep compassion and to produce a large a normal is cooling and this match anomalous coding is going to activate a strong subtropical some mechanism is easier to produce a multi year now. Nina and so it is due to this man SST in is
Jin-Yi Yu: Actually this up Eastern age of the Indo personal info.