Wieslaw Maslowski, Department of Oceanography, Naval Postgraduate School, Monterey, California, USA


Dynamical downscaling using the Regional Arctic System Model to advance predictive understanding of the Arctic climate system


We have developed and used the Regional Arctic System Model (RASM) for dynamical downscaling of global atmospheric reanalyses and future projections.  RASM is a fully coupled limited-domain ice-ocean-atmosphere-land model developed to better understand the linkages and coupling channels within the Arctic System at a process scale and to improve prediction of its change at a spectrum of timescales. Its domain is pan-Arctic, with the atmosphere and land components configured on a 50-km or 25-km grid. The ocean and sea ice components are configured on rotated sphere meshes with four configuration options: 1/12o (~9.3km) or 1/48o (~2.4km) in the horizontal space and with 45 or 60 vertical layers.

We use RASM to investigate critical processes controlling the Arctic sea ice thickness distribution, its oceanic and atmospheric forcing and air-sea interactions under a diminishing sea ice cover. Our focus and the long-term objectives are to improve the representation of feedbacks and to quantify some of the key uncertainties of the Arctic surface energy budget, to improve model predictive skill and advance predictability of Arctic climate change at time scales from synoptic to decadal.

In this talk, I’ll present several examples of key process and feedbacks, which improve model simulation of the past and present. I’ll also discuss progress with, challenges of and observational needs for advanced arctic climate prediction at sub-seasonal to intra-annual time scales.


Tuesday November 27, 11:15 am


Rossbysalen C609, Arrhenius laboratory, Svante Arrhenius väg 16C, 6th floor