Multi-decadal variability in the Bering Sea: a synthesis of model results and observations from 1948 to the present

Abstract

The northern Pacific Ocean is a highly dynamic region characterized by strong decadal signals, as evident in climate regime shifts. A regime shift marks when the climate exhibits an abrupt modification from one physical environment to another. The mesoscale variability seen in regime shifts is poorly represented in earth system models. To best understand the changes in the Arctic Ocean, we must analyze the Pacific Oceans influence on the Arctic through regional models. This study synthesizes multi-decadal results in the Pacific Ocean from the regional Arctic system model (RASM); a high-resolution, pan-Arctic, coupled model forced with atmospheric data from the Common Ocean Reference Experiment, version 2 (CORE2), 19482009 reanalysis to identify climate regime shifts. Analyzed results are validated with observational data and compared to output from the, community climate system model, version 4 (CCSM4). RASM demonstrated skill in identifying climate regime shifts. RASM-based correlations with the Pacific decadal oscillation (PDO) can explain 4060 percent of the total variability in the northern North Pacific and Bering Sea region. Limited comparisons of RASM to CCSM4 suggest there is added value in regional climate simulations and better understanding of climate regime shifts.