Polar Processes, Sea-Level Rise and Coastal Impacts Group Breakouts: 2023-06
First Breakout (Tues., June 27, 9:40 am MDT)
Plenary Room, Vail/Steamboat
| topic | leads | time | notes (e.g., what material would be useful to lead discussion?) |
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9:40 | Tropical-to-Polar Teleconnections: Does E3SM produce verifiable teleconnections in ice sheet and sea ice mass balance, or our best representation of them, in both hemispheres? | @Carolyn Begeman @Shixuan Zhang
| 10 min intro + 10 min discussion |
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10:00 | Exclusion Experiments: Can we devise a series of physics exclusion experiments to help pinpoint relevant problems to polar bias and skill? Exclusion experiments test the response of the system to changes in inputs. Examples include: A. Starting from a spun up state, and then: 1) turning off all fluxes in individual components (flywheel isolation), 2) turning off the sun (system spin down), 3) turning off individual incoming fluxes for the ocean, sea ice, land etc (component spin down). B. Starting from rest: 1) Running the whole model without solar input (system stay-at-rest), 2) Running with all component fluxes turned off (component stay-at-rest type 1), 3) Running individual components with no flux input (component stay-at-rest type 2). | @Andrew Roberts @Wuyin Lin | 10 min intro + 10 min discussion |
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10:20 | Infrastructure Needs: What infrastructure improvements, including changes to model output, coupled testing, are needed to help reach our science objectives? | @Alice Barthel @Xylar Asay-Davis | 10 min intro + 10 min discussion |
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Second Breakout (Wed., June 28, 8:00 am MDT)
Breakout Room 2, Telluride
| topic | leads | time | notes (e.g., what material would be useful to lead discussion?) |
---|---|---|---|---|
8:00 | Towards Improved Model Skill and Reduced Bias: What new physics are candidates for reducing polar biases and improving polar skill? | @Elizabeth Hunke @Stephen Price | 10 min intro + 10 min discussion |
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8:20 | Resolution vs. Numerics & Physics: What aspects of the numerics are known to need improvement, and where is there no substitute for, and dependence on, resolution? | @Darin Comeau @Xylar Asay-Davis | 10 min intro + 10 min discussion |
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8:40 | Polar Contributions to V3: How are we contributing to the V3 release and the large ensemble? How do these efforts mesh with the polar simulation campaign.
| @Andrew Roberts , @Stephen Price | 10 min intro + 10 min discussion | https://acme-climate.atlassian.net/wiki/spaces/PSC/pages/3664576543 |
Notes from 1st Breakout session:
Carolyn: Teleconnections
Which teleconnection should we look at?
[Renu] Atmospheric Rivers over the Antarctic (RGMA portfolio)
[Andrew R] the Stratosphere sees sea ice (polar vortex + atm patterns - do depend on sea ice —> impact on jet stream location/water resources over continental US)
[Renu] Arctic Atm rivers - work by Hailong
[Wieslaw] Phase 3 Hilat-Rassm looks at the Arctic to US precipitation teleconnections. Already working with E3SM people to set up E3SM-Arctic. [Carolyn] How to best collaborate? [W] any way we can
[Andrew R] useful to look at the impact of regional refinement on teleconnections.
[Steve] Difficult to publish SORRM results (given global climate biases) but teleconnections seem promising.
[Wuyin] maybe also modes of variability - looking ahead to v3: better tropical variability in atmv3. May look at polar impacts from that. Caveat: teleconnections seem worse in v3.
[Carolyn] has anyone looked at teleconnections in NARRM? [Renu] some university projects.
[Hailong] Hilat: sea ice changes impact fire risk in US. Current phase: focus on Arctic amplification. Will assess variability in Arctic-RRM? Open to looking at SORRM and sharing data from Arctic-RRM
Anyone has comments about ensemble design?
[Wieslaw] Arctic teleconnections seem to require 200+ ensemble members (cf. paper). Maybe not good news
[Steve] same said by “NCAR guy” (Fasullo?) - maybe better to focus on the SO than the Arctic.
Andrew R: Exclusion experiments
[Steve] how easy are these things? Turning the sun off might be easy but others? Andrews: depends. For sea ice, stresses are easy, fluxes are hard.
[Mark] we do that in a single component (term by term; spin-down experiments) but not in the coupled framework.
[Shixuan] How long would we need to do it for, given the ocean? [Andrew] Atm paper - sun off = spin down in 6 weeks. Ocean may be similar from spin-up timescales.
[Wuyijn] same concern about cost/timescales; and how would that actually inform the source of the bias in the coupled run?
[Luke] did some in the AMOC working group.
[Mark] need to have a theoretical answer, else it looks different but tells us nothing specific
[Andrew] could turn off the sea ice dynamics. To avoid the ice bias (sea ice going everywhere) and impacting