11th Conference on Atmospheric Radiation and the 11th Conference on Cloud Physics

Tuesday, 4 June 2002
Relationship of the Arctic and Antarctic Oscillation to the Outgoing Longwave Radiation
A. J. Miller, NOAA/NWS/NCEP, Camp Springs, MD; and S. Zhou and S. K. Yang
Poster PDF (202.0 kB)
Utilizing a combined data set of broadband outgoing longwave radiation data derived by NASA, (Wielicki et al., 2001) we show that the relationships of the Arctic and Antarctic Oscillation (AO/AAO) to the outgoing longwave radiation are well defined on the monthly time scale. Recent work by Limpasuvan and Hartmann(2000) (L&H) utilizing the NCEP/NCAR reanalyses indicate that the AO/AAO high phase minus low phase difference depicts downward motion in the mid-latitudes of each hemisphere. While it is usually very difficult to test attributes of the reanalysis, this downward motion suggests that this would be associated with a decrease of clouds and an increase in the outgoing longwave radiation (OLR). Thus, the independent OLR data provide a test of the data and results. Through both correlation analysis and composite analysis we demonstrate that a positive AO/AAO signal is, indeed, strongly associated with an increase in OLR in the mid-latitudes and vice-versa. These results also compare very well with the OLR computed within the reanalyses. This leads to conjecture as to how we may improve the current forecast system at time-scales beyond about a week.

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