Effect of certain geo-and heliophysical factors on the variability of ozone and UV irradiance fields in the tropics

The variability of the fields of the total ozone content (TOC) and UV erythemal irradiance in the tropical region (30°S–30°N) is studied. The fields of monthly means of the TOC and erythemal irradiance that are based on the TOMS 8 and SBUV 8 satellite observations over the period from 1979 through 2003, with preliminarily eliminated the linear trend and the seasonal cycle, were used as the initial data. The application of the method of empirical orthogonal functions (EOFs) to analysis of initial series made it possible to identify the characteristic spatial and temporal patterns in the fields of TOC and UV-irradiance anomalies that are closely related to solar activity and elements of the atmospheric general circulation, such as the quasi-biennial oscillation and El Niño (La Niña) phenomena. Quantitative estimates and analysis of the fields of TOC and UV-irradiance variations are presented in the study. The revealed spatial, temporal, and phase relations of the fields of ozone variations to some geo-and heliophysical factors are used in the regression model proposed for estimating monthly means of TOC in the tropics and based on the EOF decomposition.