Information communication of the northern hemisphere on intra-seasonal and over inter-annual oscillation signals

Abstract

Basic characteristics and form of intra-seasonal and over inter-annual variations were extracted through filtering using the reanalysis data of monthly geopotential height from NCEP/NCAR. Then information theory was applied to the filtered data to analyze the communication among the intra-systems between the low and mid-high latitudes. The results were found that the information loss rate of intra-seasonal oscillation signal is higher than that of over inter-annual signal, and the directions of two signals’ communication are opposite in particular regions. The information loss rate at low latitudes is higher than that at mid-high latitudes for both time scale signals, and it is distinct between the lands and the oceans in meridional average. With respect to the altitudes, the information loss rate of over inter-annual oscillation signal at low latitudes is rather high, but it is low at mid-high latitudes over all troposphere and bottom of stratosphere. For the intra-seasonal oscillation signal, the information loss rate is high at low altitude but low at high altitude. The study of communication between the low latitude and mid-high latitude of the circulation system on the two time scales provides a new way to understand the predictability and interaction of different parts in the climate system.