An improved retrieval of tropospheric nitrogen dioxide from GOME

摘要: [1] We present a retrieval of tropospheric nitrogen dioxide (NO2) columns from the Global Ozone Monitoring Experiment (GOME) satellite instrument that improves in several ways over previous retrievals, especially accounting Rayleigh and cloud scattering. Slant columns, which are directly fitted without low-pass filtering or spectral smoothing, corrected for an artificial offset likely induced by structure on diffuser plate GOME instrument. The stratospheric column is determined NO2 remote Pacific Ocean to minimize contamination NO2. air mass factor (AMF) used convert slant vertical calculated integral relative distribution global 3-D model chemistry driven assimilated meteorological data (Global Earth Observing System (GEOS)-CHEM), weighted altitude-dependent scattering weights computed with radiative transfer (Linearized Discrete Ordinate Radiative Transfer), using local surface albedos observations at wavelengths. AMF calculation accounts fraction, top pressure, optical thickness algorithm (GOME Cloud Retrieval Algorithm). Over continental regions high emissions, clouds decrease 20– 30% clear sky. almost twice as sensitive ocean than land. Comparison retrieved July 1996 GEOS-CHEM values tests both oxide radical