Time Series Analysis of Natural Variability in Barotropic Energy of the Atmosphere with ECMWF Global Analysis

[摘要] In this study, we conducted time series analyses of barotropic energy of the atmosphere using a ten-year period of ECMWF global analysis. The spectral features are compared with the idealized model simulation spectrum of Tanaka et al. (1996).We find a regime transition over the frequency domain from red to white noise in eddy barotropic energy. The red noise spectral slope at high-frequency is approximately -3. The red noise spectrum changes to white noise at low-frequency as predicted by the model simulation. The transition from red to white noise occurs, however, at the frequency 1/20 (day-1) in the observed atmosphere, compared with 1/50 (day-1) in the model atmosphere. The difference results from the higher energy level of white noise in the model atmosphere.

[学科分类] 大气科学