Temporal-Spatial Distribution of Tropospheric NO_2 in China Using OMI Satellite Remote Sensing Data

Information on monthly and yearly mean tropospheric NO_2 vertical column densities over China from November 2004 to January 2008 were reported based on remote sensing data from an OMI satellite.The information on NO_2 vertical column densities were divided into eight natural regions for the further analysis.A linear sine model was established to fit the time series from November 2004 to January 2008 for these regions.The model was used to simulate the change trends,variation periods and fluctuation ranges of tropospheric NO_2 vertical column densities through out the eight geographical regions of China.The results showed that the variation of these regions can be well simulated by the model.The results also proved that human activities play a key role in the variation of tropospheric NO_2 vertical column densities.This influence was mainly reflected in impacts on dose concentration,periodicity,and increasing trend of tropospheric NO_2 vertical column densities.