Analysis on Wintertime Atmosphere Activities in the Northern Hemisphere

The purpose of this paper is to describe the large- scale atmosphere activities in the northern hemisphere by predigesting the model. Based on NCAR/NCEP reanalysis data, the oscillation of atmosphere circulation between Arctic and middle latitude are validated on EOF, and the wintertime planetary wave activities in the northern hemisphere are examined on 2D FFT and spectral analysis with focus on their spatial distribution and temporal-spatial characters respectively. The objective variables include sea level pressure (SLP) and anomaly stream function at 850 hPa, 500 hPa and 200 hPa. The analysis reveals that the wave numbers 1~2,1~3, and the wave numbers 1~4 dominate the perturbation pattern at 70deg~80degN, 60deg~70degN and 50deg~60degN zonal belt respectively. The results accord fairly well with Rossby´s classical trough formula and are of potential use for understanding the northern hemisphere large-scale oscillations.