ECS event #31

This symposium was Feb 26, 2024

recording of the event

09:18:02 From Paulo Ceppi : Do we understand what drives the wind decrease? (Sorry if I missed it)

09:18:03 From Deirdre Des Jardins : Could this be related to the early warming of the tropical Atlantic this year?

09:18:17 From Deirdre Des Jardins : I mean in 2023?

09:19:48 From Jonah Bloch-Johnson : Replying to "Do we understand wha..."


As in, “why would wind waver?”

09:19:58 From Andrew Williams (he/him) : Reacted to "As in, “why would wi..." with 🤣

09:20:03 From Paulo Ceppi : Reacted to "As in, “why would wi..." with ❤️

09:20:07 From Deirdre Des Jardins : Reacted to "As in, “why would wi..." with ❤️

09:20:12 From Clare Singer (she/her) : Reacted to "As in, “why would wi..." with 🤣

09:20:25 From Matthew Henry : Reacted to "As in, “why would wi..." with 🤣

09:20:41 From Allison Hogikyan : Replying to "Do we understand wha..."


Paolo, thanks for the question; I’d like to flesh this out more clearly in fact. All I’ve seen so far is that it’s accounted for primarily by the zonal wind (trades) . But since this convective regime is  2D and not 1D, I suspect there is more to the story.

09:20:52 From Allison Hogikyan : Reacted to "As in, “why would wi..." with ❤️

09:21:10 From Paulo Ceppi : Reacted to "Paolo, thanks for th..." with 👍

09:21:17 From Deirdre Des Jardins : Reacted to "Paolo, thanks for th..." with 👍

09:21:29 From Florian Roemer : Reacted to "As in, “why would wi..." with 🤣

09:24:08 From Zhihong Tan : Great work! Is your mechanism more related to meridional shift of ITCZ, or to the change in Walker circulation strength (both may affect the strength of the near-equatorial easterlies). Also, is it related to the wind-evaporation-SST feedback (e.g., Xie and Philander 1994)?

09:25:00 From Allison Hogikyan : Replying to "Could this be relate..."


Certainly, since we are in an El Nino now, I would expect that these feedbacks are in play in the Pacific. My understanding, however, is that the temperature anomaly last year emerged before the el nino driven anomaly would have showed up.


there is a broader question of whether this mechanism shows up on longer time scales with global warming, but it’s a bit tougher to tease out for a variety of reasons: relatively uniform warming (relative to ENSO) and strong changes in the sfc energy budget associated with forcing which needs to be separated from ‘feedbacks’

09:26:35 From Allison Hogikyan : Replying to "Great work! Is your ..."


Thanks, Zhihong. so the WES and WISHE feedbacks are particular applications of this fact that LH flux depends on wind speed. I’m not sure the shift in ITCZ and change in Walker are really two different things…?

09:27:04 From Andrew Williams (he/him) : Reacted to "Paolo, thanks for th..." with 👍

09:27:24 From Allison Hogikyan : Replying to "Great work! Is your ..."


Note WES is focused on the southeast Pacific, whereas the convective regime is almost never there. so this really is a different application

09:28:40 From Deirdre Des Jardins : Replying to "Could this be relate..."


There was a record 2.4 C anomaly at 250 hPA over the tropical Atlantic in Oct 2023, 0.7 C higher than the previous record in Sept 2015.  Sept & Oct 2023 had 5 std temp anomalies at 250 hPA.

09:29:12 From Deirdre Des Jardins : Replying to "Could this be relate..."


Compared to the 1971-2000 climatology.

09:31:05 From Zhihong Tan : Replying to "Great work! Is your ..."


Sure, I agree that the ITCZ and Walker responses are coupled. Nevertheless, there has been some work on decomposing the tropical circulation response to a local Hadley response (meridional shift of the local ITCZ and change in overturning strength) and a Walker response (e.g., Raiter et al 2020), which may help clarifying the mechanism you proposed.

09:32:35 From Deirdre Des Jardins : Reacted to "Sure, I agree that t..." with 👍

09:53:11 From Daniel Feldman : @Timothy Cronin (he/him) Thanks for the great presentation. Since stratospheric masking is found to be significant Planck feedbacks, what are the implications your work for feedback analysis for transient events including stratospheric warming associated with stratovolcanic eruptions (or other aerosols in the stratosphere)?

09:53:31 From Deirdre Des Jardins : Hunga Tonga

09:55:13 From Deirdre Des Jardins : The water vapor from Hunga Tonga took awhile to move to the Northern Hemisphere?

09:58:24 From Jonah Bloch-Johnson : @Allison Hogikyan - have you looked at whether the “patchiness” of a given el nino affects the intensity of the wind change? just thinking of heng quan’s work on circulation/convective aggregation associated with tropical warming be nonlinear based on patchiness

09:58:34 From Deirdre Des Jardins : Reacted to "@Allison Hogikyan - ..." with 👍

09:58:35 From Clare Singer (she/her) : 📢📢 CFMIP 2024 deadline! 📢📢


Abstract submission deadline is this FRIDAY (Mar 1).


The conference will take place June 3-6 at Boston College. More details and abstract submission link on the website: 


https://sites.bc.edu/cfmip2024/


We'll have sessions on:

- Convective organization

- Cloud processes (phase, precipitation, radiative effects)

- Cloud, circulation, and teleconnection

- Climate feedback and sensitivity

- Tropical warming pattern formation mechanisms

- Energy imbalance

09:58:56 From Jonah Bloch-Johnson : Reacted to "📢📢 CFMIP 2024 dead..." with ☁️

09:59:08 From Zhihong Tan : Reacted to "📢📢 CFMIP 2024 dead..." with 👍🏽

09:59:18 From Steve Klein : Reacted to "@Allison Hogikyan - ..." with 👍

09:59:19 From Steve Klein : Removed a 👍 reaction from "@Allison Hogikyan - ..."

09:59:29 From Andrew Williams (he/him) : Reacted to "📢📢 CFMIP 2024 dead..." with ☁️