Marysa Lague (Univ. of Utah): "Half-land, half-water planets: continental configuration & the water vapour greenhouse effect"
Cristian Proistosescu (UIUC): "Can we learn spatial radiative feedbacks from a short satellite record? Insights from a hierarchical approach"
Kezhou Lu (Georgia Tech): "Mechanisms of Fast Walker Circulation Responses to CO2 Forcing"
12:21:30 From Paulo Ceppi To Everyone:
Is the air-sea coupling feedback estimated from control runs? And are the values averaged over a specific region?
12:22:21 From Zhihong Tan To Everyone:
How good is the correlation between air-sea coupling and ENSO response across models? Can we use the observation to develop an emergent constraint?
12:23:38 From Allegra N. LeGrande To Everyone:
Can you check your results wrt fast response using the VolMIP ensemble
12:25:16 From Michela Biasutti To Everyone:
Is it a linear relation between the feedback intensity and the fast cooling?
12:28:09 From Thorsten Mauritsen To Everyone:
Just for info, in the MPI model we tuned the ENSO frequency with the convection scheme. I tend to think it is about right for mostly the wrong reasons, though.
12:28:10 From Karsten Haustein (he/him) To Everyone:
Great talk! Immense amount of super interesting work!
iirc, ENSO temporal variability between CMIP models is huge (i.e. El Nino can occur way more frequent than observed). I’m wondering whether this might be linked to the air-sea coupling strength as well?
12:28:31 From Kezhou Lu To Everyone:
Replying to "Is it a linear relat..."
Hi Michela, thank you for your question! I see a postive relationship between FB and fast cooling, but I can’t say it is strictly linear.
12:30:06 From Kezhou Lu To Everyone:
Replying to "Great talk! Immense ..."
Hi Karsten, thank you for your question! Yes, I think they are relevant but I haven’t got a good framework to quantify the ENSO yet.
12:31:03 From Kezhou Lu To Everyone:
Replying to "Just for info, in th..."
Huh, good to know! I will definitely ask you more questions later if I need. Haha
12:32:22 From Karsten Haustein (he/him) To Everyone:
Replying to "Great talk! Immense ..."
Thanks Kezhou! I remember an obscure paper that looked at Pacific EOFs in CMIP5. But not sure that helps to quantify things in a systematic way.
12:33:48 From Kezhou Lu To Everyone:
Replying to "Great talk! Immense ..."
@Karsten Haustein (he/him) Interesting! I have to search and read it. I also remembered reading one about Pacific EOFs of cold tongue, and that one seems relevant to my paper.
12:33:55 From Kezhou Lu To Everyone:
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12:34:46 From Thorsten Mauritsen To Everyone:
Replying to "Just for info, in th..."
No problem, let me know if you have any questions. You can start here, around Figure 9, https://doi.org/10.1029/2012MS000154
12:35:04 From Kezhou Lu To Everyone:
Replying to "Just for info, in th..."
Thank you so much!! 🙂
12:41:09 From Karsten Haustein (he/him) To Everyone:
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12:41:34 From Zhihong Tan To Everyone:
Very impressive work! It would be interesting to repeat these experiments with a GCM with clouds because the cloud radiative effects can compensate partly the water vapor effect (drier planet has fewer low clouds and SWCRE, but may still have abundant high clouds and LWCRE).
12:42:21 From Gavin Schmidt To Everyone:
was the ocean model dynamic?
12:42:23 From Angel Peinado To Everyone:
Very nice presentation! I was wondering how much is the change in the general circulation between these experiments.
12:42:34 From Karsten Haustein (he/him) To Everyone:
Replying to "Great talk! Immense ..."
@Kezhou Lu The link to the paper doesn’t work anymore. Z Fang et al (2014) … mostly written in Chinese. No idea how I found it back then 😄
12:42:55 From Allegra N. LeGrande To Everyone:
Anything to be learned about earth configurations like the Eocene (w super warm NP) from the polar land experiment?
12:45:55 From Marysa Lague To Everyone:
Replying to "was the ocean model ..."
All slab ocean runs, with 20m slabs and no imposed heat transport (for the Isca runs; the CESM runs briefly shown at the start have pre-industrial, seasonally varying heat transport, still in slab ocean)
12:46:24 From Gavin Schmidt To Everyone:
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12:47:15 From Marysa Lague To Everyone:
Replying to "Very nice presentati..."
HUGE! The Hadley Circulation of LandWorld and TropicsLand is hilarious. They’re so dry that the Hadley cell isn’t driven by latent heat flux, just by sensible heat flux, so the upwards motion in the tropics only gets a few hundred hPa above the surface before it “runs out of steam”, then you get a “backwards” overturning cell above those super stubby tropical “Hadley” cells!
12:49:19 From Angel Peinado To Everyone:
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12:49:49 From Marysa Lague To Everyone:
Replying to "Anything to be learn..."
Probably - this I think ties in to the last spoken question, about how much these kinds of feedbacks might be at play in the modern Arctic, too. I think we don’t know (a) how big it is now or (b) if it might have been important during the Eocene, but I’ve wanted to run these with actual paleo continental configurations to see if these same things were indeed at play. I ran them for the last 600 mya every 100 years a couple of months ago, so I have 100 mya which is the closest one to the Eocene I think, I just haven’t looked at the results yet.
12:51:32 From Allegra N. LeGrande To Everyone:
Replying to "Anything to be learn..."
Neat! But might be cool to do finer slices in the tertiary when earth has such a huge change in base temp
12:52:08 From Marysa Lague To Everyone:
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12:52:39 From Marysa Lague To Everyone:
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Yeah, did the 600 mya simulations for very different reasons :p
12:56:16 From Angel Peinado To Everyone:
Replying to "Very nice presentati..."
Fun experiments!! Thanks for the plot! It puzzles me tropical land cause it seems to have an anti-Hadley cell or so, but then I got the feeling that the moisture transport and zonal distribution play a major role, which is entangled with the land configuration haha
12:56:46 From Allegra N. LeGrande To Everyone:
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12:57:07 From Angel Peinado To Everyone:
Replying to "Very nice presentati..."
Have you checked the zonal energy budget?
12:58:12 From Marysa Lague To Everyone:
Replying to "Very nice presentati..."
Yeah; the EastLand plot above is hiding a lot of the cool stuff that actually happens (superrotational winds in the tropics). The TropicsLand case is the one where the Hadley circulation is totally dry which is why it is so weak, then has the anti-Hadley cell above it.
12:58:47 From Marysa Lague To Everyone:
Replying to "Very nice presentati..."
I have looked at zonal energy budgets… what in particular?
12:59:03 From Marysa Lague To Everyone:
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(Pretty big spread in atmospheric heat transport across these runs, too)
12:59:23 From Marysa Lague To Everyone:
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(Which isn’t in the paper; will write it up eventually...)
13:00:26 From Angel Peinado To Everyone:
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I wonder how much it can provide a hint of the circulation and how the energy at the surface varies.
13:00:41 From Angel Peinado To Everyone:
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Writing papers is the hard part haha. The fun part are the experiments 😄
13:00:58 From Marysa Lague To Everyone:
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13:01:00 From Marysa Lague To Everyone:
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AGREE
13:03:36 From Angel Peinado To Everyone:
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I will be waiting for your paper! I wonder how will you disentangle land to circulation and water vapor distribution
13:04:16 From Deirdre Des Jardins To Everyone:
Precip in California. 🤩
13:04:25 From Marysa Lague To Everyone:
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13:05:04 From Thorsten Mauritsen To Everyone:
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Did you consider how possible model bias in your prior can reflect on the result?