 I'm going to turn the gear a little bit and I'm not going to talk about prediction per say, but talk about a very important component of S2S prediction that is errors interaction. I hope at the end of my talk, I will convince you that whatever you know about errors interaction to this point can be updated a little bit. I also hope I don't have to convince you how important errors interaction is to S2S availability, including prediction. So let me just jump start and this cartoon illustrated what we know about errors interaction to this point. That is errors interaction is about exchanges of energy, momentum and material through the errors interface. We have a sensible heat flux. We have a latent heat flux or evaporation fresh freshwater input. We have momentum flux and fluxes of different gases. Over the centuries, most of the studies of errors interaction focus on errors in fluxes. And we still have not fully resolved this problem yet. For example, the fluxes of gas is still a ongoing research. We still need to make accurate measurement of variables near the surface to accurate estimate errors in fluxes. And even after Togo Core, we have this wonderful core algorithm, flux algorithm, and there's still room to improve. And we still do not have a global observations of errors in fluxes. So there's still a lot of a blind spot over the ocean where we do not have direct observations of errors in fluxes. We have to rely on estimate from numerical models and sidelight and then we know they're not accurate. So this traditional errors interaction problem has not been solved. However, we cannot stay at the ocean surface forever. Let me point two things to you about errors interaction. First, from atmospheric point of view, once we have the energy or gas from the sea surface into atmosphere, it does not uniformly distribute in the boundary layer. And we know that the temperature profiles and humidity profiles and you can guess the gas profile has very rich structure within the boundary layer, within the lowest one kilometer, for example. And also for the error sea interaction or the error sea fluxes to influence local and global weather and climate, the energy, the gases has to propagate or spread from the ocean surface to the entire atmosphere. And that usually is done through deep convection, for example, moisture. But in order for the water vapor, for example, evaporated from the ocean surface to affect deep convection in the tropics, we have to consider many processes such as convective downdraft, entrainment and vertical eddy transport. So to fully realize the impact of error sea interaction or error sea fluxes to weather and climate, we have to understand how the energy momentum and the gas being distributed through atmosphere boundary layer above the ocean surface. And this is just an example of observations and I'm just cut the lowest part of the sounding observations from a ship. And in the lowest one kilometer that's marked by the white line, and you can see relatively humidity in the upper panel, vertically it's not very well mixed and sometimes they have pretty good vertical profiles. And the vertical eddy flux of moist static energy also has a very rich variability within the boundary layer. So to all point out that we have to relate the boundary layer to error sea fluxes in order to fully understand how error sea fluxes influence the weather and climate locally and globally. Now if you go to the ocean and it has been several decades since we realized that the ocean mix layer also has very rich vertical structures. The salinity and the temperature profiles can vary based on the wind forcing based on freshwater input based on based on the solar energy input. It can create the different layers. You can have a mix layer, you can have a barrier layer and until you reach thermal collide and all those virtual structures influence the, how a sea surface temperature varies, and that would directly affect surface fluxes. And this is an example of field observations from a ship. And I don't want to go to detail. I just point out the upper two panels represent the momentum flux and the heat flux. And then the colored panel represent all different variables such as a zoom away in temperature salinity and turbulence and from surface down to about 150 meters, and you can see those very rich variability vertically and time wise in the upper part of the ocean. And those, all those variabilities would influence the surface temperature and influence surface fluxes. So you put everything together, you'll find out there's a many interesting variables at both sides of the air sea interface in the atmosphere, we have the wind shear, we have cold pools, and we have diagonal variability in the boundary layer, we have updraft, downdraft, and those all influence air sea fluxes. And then on the other side below the air sea interface, we have ocean eddies, we have the internal waves, and we have buoyancy driven vertical convection and shear driven turbulence, and many, many other things that all help distribute energy momentum and gas from the air sea interface downward to the upper part of the ocean. And those all think together from the upper layer through from the upper ocean through air sea interface to the atmosphere and boundary layer form an air sea transition zone, and air sea interaction should not happen just at the air sea interface, but through the entire transition zone. That's my point. And I recommend, we think differently about air sea interaction from now on, not just the focus on air sea interface, but include the operation interface and the atmosphere and boundary layer as a single identity that we call air sea transition zone. And we study air sea interaction through this transition zone. This has been done to a different extent in the past studies, but I want to emphasize that to fully understand this, we will have to have simultaneous and co-locate observations of these air sea transitions. This means we have to observe the atmosphere boundary or ocean surface and the upper ocean simultaneous. Technology wise, at this point, ship is still the best way to do such observations because we can install all kinds of observations of the atmosphere and ocean and surface. For example, the other one possibility is airplane drop sounds and airplane can launch the drop sounds, measure the vertical profile of the atmosphere, then go into the ocean to measure the ocean. This is just an example of ship measurement of both atmosphere and ocean for temperature and the wind. This is the example of airplane measurement of upper ocean and the atmosphere through a transaction. Both of them are pretty good with one exception that both of them are expensive and logistically challenging. You have to arrange the ship, you have to arrange airplane and the coverage of their observations are still limited. The future observations probably will depend on the new technology, especially the technology of autonomous uncrewed devices. We have many of them, from left to right is kind of a time span, left is what do we have and to the right is in the future. We can have a different type of advanced technology to observe the atmosphere, the air sea interface and upper ocean simultaneous. I'll just give you one example that is currently feasible and we have uncrewed surface vehicles such as sail dream and you can see the red sailboat. And we have ocean gliders in the upper ocean can profile the ocean temperature 70 and current. And we can fly an air drone above that and all the three together can give us a continuous profile of the upper ocean air sea interface and the atmosphere boundary layer. And this is technology speaking, this is feasible. And at this moment that we are trying to practice the sail drone and the glider coordination to see how what's the best way to coordinate them to measure the upper ocean and air sea interface together. And in the near future we'll add the air drone above it and so we can have the entire profile through the air sea transition zone and to help to study the air sea interaction in a new way. I'll stop here so basically the bottom line is that we probably will think differently at sea interaction and go beyond the air sea interface to both sides. And the take air sea transition zone as the place where air sea interaction takes place. I'll stop here and take questions. Thank you. Thanks. Yeah, it's a really good redefinition and revolutionary. Any questions for Chidang on this? While we wait for questions Chidang, could you comment briefly on this redefinition or rethinking of the transition layer, how you would foresee this being improving our earth system models, specifically like improving S to S predictions, right. So who should we change our modeling of this transition layer in addition to observing it should be modeled this as a transition zone component of the earth system or should we still be having an atmospheric model and an ocean model but have this transition zone model then as a coupling component of the two. Yeah, that's an excellent question. You know, I'm not a model based my based on my limited knowledge right now. In most cases people develop atmosphere model and ocean model separately and develop the coupler so called a coupler so put them together and I think at least if we develop a comprehensive coupler based on this new definition of direction probably the coupler should not cover only the interface should probably extend to the to the upper ocean boundary I don't know exactly how to do that yet. But most importantly is, you know, if you really want to study the earth system as a as a integrated component. And then when you develop model it should start start develop a couple of model simultaneous rather than atmosphere model and ocean model separately and then couple them together. I think that that has been the 2020 century practice and in 21st century, we should think differently in terms of model development. Thanks. Any other questions for children. So, are you envisioning this like a observation process study or a campaign in any specific region around the globe. Right now, yes, right now I mentioned that we are trying to coordinate the children's with the gliders we tried that once in the north Pacific winter storm and currently we're practice we're practicing that in the tropical Atlantic during hurricane season. And in the future, potentially actually in this hurricane season we should have air drone but the development of that particular drone was delayed so we didn't have that. But yes, in the near future, that's that's what we want to do we want to find opportunity to put all three together just to see to what extent we can measure the opera the entire transition zone simultaneously using the coordinated types of vehicles. Yeah. Last chance one final question put you down. Okay. Thanks a lot. I don't see other questions for now. We might have more questions during the break that we have. Thank you for joining us. The networking session for the next 15 minutes.