Observations of Tropospheric Ozone Profiles Using Simultaneously Measured UV and IR Radiances from OMI and TES

Abstract

Ozone is a radiativelly and chemically important trace gas in the atmosphere. Accurate monitoring of ozone vertical distributions is crucial for a better understanding of air quality and climate change. The Geostationary Coastal and Air Pollution Events (GEO-CAPE) mission, an Earth Science Decadal Survey mission that has been recommended for launch in the 2013-2016 time frame by National Research Council, will measure tropospheric ozone and its precursors relating to air quality over the Americas. To improve current capability of tropospheric ozone sounding in terms of spatial and temporal resolution, GEO-CAPE mission calls for an instrument(s) that is sensitive over multiple spectral regions. Prior to the launch of GEO-CAPE satellite, using simultaneous measurements of multiple sensors of an ongoing satellite mission provide an alternative way to improve tropospheric ozone sounding and help in the evaluations of suitable spectral regions for the GEO-CAPE mission. The Ozone Monitoring Instrument (OMI) and the Tropospheric Emission Spectrometer (TES) are both on the Earth Observing System Aura satellite in orbit. They are providing ozone concentration profiles measurements respectively. OMI is a nadir-viewing pushbroom ultraviolet-visible (UV-VIS) imaging spectrograph that measures backscattered radiances covering the 270-500 nm wavelength range. TES is a Fourier transform spectrometer that measures the thermal infrared (TIR) light radiances emitted by Earth's surface and by gases and particles in spectral range 650 - 3050 cm-1. We present an approach to combine simultaneously measured OMI UV and TES TIR radiances to improve the tropospheric ozone sounding. The results from combination of these measurements are presented and discussed. The improvements on tropospheric ozone profiles from the UV+TIR joint retrievals, as compared with either spectral region alone, are charterized using the ozonesonde measurements.