Retrieval Experiment Of Total Atmospheric O₃from OMI Data

ABSTRACT:Ozone (O3) is an important trace gas in the atmosphere. The concentration distribution and changing of atmospheric O3affects not only the changing of climate and environment, but also the health, life and production activities of human. So the research of atmospheric O3owns the vital significance. Satellite remote sensing technology has the advantage of widely, periodic observation and well spatial continuity. So it can be widely applied to the detection of atmospheric O3. With the satellite remote sensing technology, we can measure the total distribution and vertical distribution of atmospheric O3, which can make up for a lack of observation of surface-based observing stations in spatial scale. In this paper, we used back-scattered ultraviolet method for obtaining total amount of atmospheric O3, focused on the properties of backscattered ultraviolet radiation, analyzed the basic principle of TOMRAD which is a forward model as well as a retrieval model, established a meteorological database, selected appropriate ultraviolet band region, retrieved total atmospheric O3from the level1top-of-atmosphere radiation and pre-computed radiance tables. The main work is below:(1) Introduced the status of satellite observations of atmospheric O3in ultraviolet band and back-scattered ultraviolet method at home and abroad.(2) Focused on the properties of backscattered ultraviolet radiation, analyzed the effects of molecular-scattered, absorption of trace gas, cloud-scattered, aerosol-scattered and surface reflection on back-scattered ultraviolet radiation.(3) Analyzed the basic principle of TOMRAD, established meteorological database, selected appropriate input parameters, ran forward model to obtaining output data, then finished pre-computed radiance tables which were used for retrieval.(4) Analyzed the algorithm of retrieval, then designed process of retrieval, mainly including:Initial total ozone estimation, O3and temperature climatology correction and correction of errors due to episodic events.(5) According to the process of retrieval, we developed programming system of retrieval, including the following functions:download system of top-of-atmosphere radiation product of OMI level1, download system of effective cloud pressure product of OMI level2, download system of surface pressure data, system of retrieval of total atmospheric O3, system of image clipping and mosaic. (6) Evaluated the accuracy of retrieval briefly, and simplified analyzed error of retrieval.By analyzing programming system and the results of retrieval, it showed that the programming system of retrieval conformed to the requirement of producing in speed and quantity, the results of retrieval were in good precision, and which can well reflected the changing trends of total O3distribution with latitude or season.