GC31A-1165
Regional Arctic System Model (RASM): A Tool to Address the U.S. Priorities and Advance Capabilities for Arctic Climate Modeling and Prediction

Wednesday, 16 December 2015
Poster Hall (Moscone South)
Wieslaw Maslowski1, Andrew Roberts1, John J Cassano2, William J Gutowski Jr3, Bart Nijssen4, Robert Osinski5, Xubin Zeng6, Michael Brunke6, Alice Duvivier7, Joseph Hamman8, Saffia Hossainzadeh9, Mimi Hughes2 and Mark W Seefeldt2, (1)Naval Postgraduate School, Monterey, CA, United States, (2)University of Colorado at Boulder, Boulder, CO, United States, (3)Iowa State University, Ames, IA, United States, (4)University of Washington Seattle Campus, Seattle, WA, United States, (5)The Institute of Oceanology Polish Academy of Sciences, Sopot, Poland, (6)University of Arizona, Tucson, AZ, United States, (7)CIRES, Boulder, CO, United States, (8)Applied Physics Laboratory University of Washington, Seattle, WA, United States, (9)University of California Santa Cruz, Santa Cruz, CA, United States
Abstract:
The Arctic is undergoing some of the most coordinated rapid climatic changes currently occurring anywhere on Earth, including the retreat of the perennial sea ice cover, which integrates forcing by, exchanges with and feedbacks between atmosphere, ocean and land. While historical reconstructions from Earth System Models (ESMs) are in broad agreement with these changes, the rate of change in ESMs generally remains outpaced by observations. Reasons for that relate to a combination of coarse resolution, inadequate parameterizations, under-represented processes and a limited knowledge of physical interactions.

We demonstrate the capability of the Regional Arctic System Model (RASM) in addressing some of the ESM limitations in simulating observed variability and trends in arctic surface climate. RASM is a high resolution, pan-Arctic coupled climate model with the sea ice and ocean model components configured at an eddy-permitting resolution of 1/12o and the atmosphere and land hydrology model components at 50 km resolution, which are all coupled at 20-minute intervals. RASM is an example of limited-area, process-resolving, fully coupled ESM, which due to the constraints from boundary conditions facilitates detailed comparisons with observational statistics that are not possible with ESMs. The overall goal of RASM is to address key requirements published in the Navy Arctic Roadmap: 2014-2030 and in the Implementation Plan for the National Strategy for the Arctic Region, regarding the need for advanced modeling capabilities for operational forecasting and strategic climate predictions through 2030. The main science objectives of RASM are to advance understanding and model representation of critical physical processes and feedbacks of importance to sea ice thickness and area distribution. RASM results are presented to quantify relative contributions by (i) resolved processes and feedbacks as well as (ii) sensitivity to space dependent sub-grid parameterizations to better understand their importance in reducing uncertainty and improving prediction of arctic climate change.

<< Previous Abstract | Next Abstract >>