Impact of atmospheric waves on the Arctic Oscillation over the Northern Oceans.

Characterized by North-South vacillation of the eastward Jet (between 40 [degrees] N and 60 [degrees] N) over the oceans, the Arctic Oscillation (AO) is a dominant mode of Northern Hemisphere climate variability, governing global weather and temperature distribution. In this study, the role of atmospheric waves in maintaining this climate mode is investigated using composite techniques based on the monthly time series of the AO amplitude. Given the National Center for Environmental Prediction and National Center for Atmospheric Research (NCEP/NCAR) Re-analyses, daily winds, temperature, and Geopotential heights around the globe will be analyzed to elucidate heat and momentum fluxes due to waves. The wave forcing of the basic circulations will be examined particularly over the northern oceans where the Jet fluctuation is strongest. The hypothesis is that while synoptic-scale wave (related to storms) and planetary-scale waves are both important in accelerating the eastward wind, their relative contribution differs over the North Pacific and North Atlantic oceans. Knowledge about the AO-related forcing mechanism by atmospheric waves is essential to our understanding of the climate, of how anthropogenic influence will modify future climate and of forecasting in the 10-15 day range.

Jamie Wirth
Department of Physics
Coastal Carolina University