V. V. Efimov and M. V. Shokurov
Marine Hydrophysical Institute, National Academy of Sciences of Ukraine, ul. Lenina 28, Sevastopol, 335000 Ukraine
Received February 3, 1999
Abstract—Bispectral analysis of time series, i.e., spectral expansion of third moments, is used to analyze vari-
ations in the geopotential at the 500-mb pressure surface. The real and imaginary parts of bispectra are calcu-
lated from data obtained during a 43-year period. The patterns of the bispectra in the Northern Hemisphere are
considered in the low–low and low–high frequency regions. It is shown that a low-frequency component, which
reaches a maximum in the region of storm tracks, arises from high-frequency interactions (synoptic scales). Its
phase shift relative to the envelope of groups of high-frequency fluctuations is considered. It is noted that vari-
ations in the intensity of synoptic fluctuations play the determining role in the generation of low-frequency
intraannual anomalies of atmospheric circulation.
Pleiades Publishing home page | journal home page | top
If you have any problems with this server, contact webmaster.