Kris Karnauskas (CU Boulder): "How Fast is the Mean Upwelling in the Equatorial Pacific Ocean?"
Tess Wei-Ping Jacobson (NASA GISS): "Pacific Decadal Variability and Its Hydroclimate Teleconnections in CMIP6 Models"
PJ Tuckman (UChicago): "ENSO and West Pacific Seasonality Driven by the South Asian Monsoon"
00:23:11 Vincent Cooper: I have a Q but can’t find the raise hand button on my fancy zoom update
00:24:41 Steve Klein: For TJ, this is a basic question. How can the aquaplanet have an ENSO? What forces a maximum of SST variability at 270E in the model?
00:28:32 Radley Horton: Curious if you can see a kind of stepwise progression, say week by week of convection to the east and perhaps south, say between July-and Oct. I have an intuition, possibly wrong, that there is quite a bit of southwesterly (not just westerly) ‘pull’ by September and October of convection through Western and eventually central Indonesia (arguably a bit south of the region you are describing). Maybe this is a separate phenomenon though
00:31:32 Sujatra Bhattacharyya: I have a question for PJ, during summer monsoon, in reanalysis, low level winds are westerlies only upto maritime continent, it doesn't go to west pacific (the defined domain) because of the pacific anticyclone which drive easterlies. Although in the model, the westerlies continues all the way to central pacific. Have you seen this part?
00:43:36 Eric: Any thoughts on what causes the bimodality?
00:46:48 Alex Parsells: Hey Tess, nice talk, I just was wondering — do you have any ideas/guesses about what causes the models to underestimate the decadal variability?
00:46:50 PJ Tuckman: Replying to "Curious if you can s..."
This is worth looking into, our simplified model probably does not the details of winds over Indonesia correct so we would need to use a more complete model
00:47:34 Radley Horton: I wonder if, at longish time scales, Bering Sea ice could influence Aleutian low strength and location (certainly Aleutian low would have more power in explaining Bering sea ice at shorter/~ annual timescales)
00:47:40 PJ Tuckman: Replying to "I have a question fo..."
Good question, the figure I showed with September winds was from reanalysis, there are westerlies extending into the West Pacific in that month. It does depend strongly on latitude and month
00:49:06 Radley Horton: Replying to "Curious if you can s..."
FWIW I believe the rainy season progression from NW Sumatra down through Have and points east is delayed by multiple weeks typically during El Niño years
00:49:22 Radley Horton: Replying to "Curious if you can s..."
Java
00:54:34 Tess Jacobson: Replying to "Any thoughts on what..."
I * think * (from some really simple tests we did with synthetic noise timeseries) that the bimodality in trends can arise directly from observations being redder (more low freq variability) than models, with some dependence on trend length
00:56:57 Tess Jacobson: Replying to "Hey Tess, nice talk,..."
Thanks, Alex! We have some guesses, but ultimately the processes involved in setting the decadal timescales of PDV are multiple and complex… one possibility is that it could be due to an insufficient coupling between the North Pacific and tropical Pacific.
00:57:33 Alex Parsells: Reacted to "Thanks, Alex! We hav..." with 👍
00:57:58 Eric: Replying to "Any thoughts on what..."
Thanks, that's reasonable.