The 5th Conference on Polar Meteorology and Oceanography

P1.15
ARCTIC OSCILLATIONS

Andrey Proshutinsky, University of Alaska, Fairbanks, AK; and M. Johnson and I. Polyakov

The primary goal of this poster is to show robust variations of the Arctic System and major factors maintained variability and interdependence of hydrologic and meteorologic processes occurring in oceanic and terrestrial regions of the Arctic. Recently observed changes in the Arctic Ocean's hydrography have highlighted the need for a better understanding of the arctic system dynamics. This research is also motivated by: - recent finding of two regimes of Arctic ice-ocean circulation described by Proshutinsky and Johnson (1997), and - the Arctic Oscillation (AO) recently identified by Thompson and Wallace (1998) in the first EOF of monthly-mean winter atmospheric pressure records. The present analysis extends our previous research for period 1899-1998 based on monthly mean sea level atmospheric pressure gridded data. Missing data (1899-1939) for polar region were reconstructed. The oscillating behavior (period is 10-15 years) of the model Arctic Ocean is evident throughout our imulations. We call this an Arctic Ocean Oscillation (AOO), and the atmospheric fields, sorted into the multi-year regimes of the AOO, reveal an Arctic Atmosphere Oscillation (AAO) which differs from AO described by Thompson and Wallace (1998).
Recent sea level pressure data suggests that the arctic
ocean-atmosphere system will shift, or has already shifted, from its
present cyclonic state to an anticyclonic state similar to that seen
previously. Further, we speculate that the recent and unusually strong
cyclonic state of the arctic system may have forced a new salinity anomaly
in the GIN seas as it was observed in late 1960s (Great Salinity Anomaly).
Analysis of long term changes in the high-latitude climate
should account for these oscillations in order to avoid aliasing the decadal
signal.

The 5th Conference on Polar Meteorology and Oceanography