O02: Implementing Scale-Aware Sea Ice Ridging in E3SM

Full Title

Implementing Scale-Aware Sea Ice Ridging in E3SM

First Author

  • @Andrew Roberts

    • afroberts@lanl.gov

All Authors

@Elizabeth Hunke

Topic

Ocean - Ice

Project

E3SM

Abstract

For some time, is has been apparent that a core state-space descriptor of sea ice models, the thickness distribution, g(h), insufficiently describes pack morphology necessary for representing features integral to coupled modeling:  snow-on-sea-ice, melt ponds, oceanic and atmospheric drag, land fast ice, and sea ice strength.  A significant problem with g(h) is that it offers only a glimpse of the much richer morphological sea ice state describing sub-grid scale ice roughness and porosity seen in the real world. g(h) itself relies on a constant dynamic density of ice through the thickness, h, when in reality, macro-porosity, 𝜙, is non-uniform in ice rubble build-up during ridging, and can result in as much as 30% reduction in local pack density. We are implementing a new variational approach to ridging in E3SM that tackles this problem, and extends the thickness state space to include macro-porosity with a distribution g(h,𝜙) to replace g(h).  This work builds upon three publications that established the theory of variational ridging, verified idealized results against a discrete element model of ridges, and evaluated a column implementation of the new ridging model against a large dataset of deformed Arctic sea ice. The method has also been favorably assessed against sea ice topography detected by ICESat-2 in an independent study. Based on these developments, we outline here the implementation and evaluation plan using orbital emulators to be completed during E3SM Phase III.

In-person

We are at the meeting, but the poster is virtual

Poster

 

Discussion Link

https://acme-climate.atlassian.net/wiki/spaces/ICE/pages/3833365075