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

 

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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

  • Present SORRM teleconnections analysis and discussion questions

  • Angles to explore:

    • Impact of regional refinement on teleconnection representation

    • Connection with ozone changes

  • Teleconnections to explore:

    • IPO and connection with atmospheric rivers

      • Renu brought up ARPA project on atmospheric rivers that we could connect with to see how they relate to Arctic teleconnections

      • CMIP models generally do not represent IPO phase well. E3SM may have an advantage there

    • Arctic polar vortex, stratospheric conditions impact on the jet stream

      • Wieslaw suggested working with HiLAT RASM folks (Hilong Wang). Possibility of attending the HiLAT Phase 3 meeting in September (contact Wieslaw if interested)

      • Connect with wildfire researchers on the E3SM team that are looking at the relationship with Arctic sea ice

  • Ensemble design:

    • Some modes of variability may require 100s of ensemble members to characterize (e.g., 200 ensemble members for some Arctic teleconnections)

    • However, the number of ensemble members needed is in relation to our particular configuration’s signal to noise ratio. Thus, the prior estimates may not be a good indication for E3SM. Contact Wieslaw for more details about his work in prep.

  • Other considerations:

    • v3 appears to have higher fidelity tropical modes of variability but v2 appears to have better tropical to South Polar teleconnections

    • Renu also indicated that there will be more teleconnections-related projects down the line but they are not funded yet

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

 

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

  • On polar campaign needs from Omega:

    • Xylar: we may need GM in polar regions even at ~2-5 km resolution Omega

    • Luke: we do plan to add GM and other eddy parameterizations in 2026

    • There is a need for more conversation between polar group and Omega to ensure effective transition from MPAS-Ocean

  • On model output needs:

    • Luke: don’t cut polar output too much because the “light“ I/O configuration may become standard

    • Elizabeth: we don’t need more sea ice output, just more sea ice analysis in MPAS-Analysis

    • Andrew: consider high-frequency output to understand model behavior better

  • On testing:

    • The polar group’s needs should be better represented in E3SM ocean developer’s test suite

Second Breakout (Wed., June 28, 8:00 am MDT)

Breakout Room 2, Telluride

 

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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

 

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

 

 

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