Surface ozone observation from Aura satellite using multispectral (TIR and UV) retrievals

Using spectral radiances simultaneously measured by the TES (thermal infrared) and OMI (ultraviolet) instruments on EOS-Aura satellite, we demonstrate the first coincident multispectral retrievals of ozone from space. We evaluate the ozone concentration from multiple spectral retrievals against ozonesonde data that were measured during the time period spanning from 2004 to 2008 and the Environmental Protection Agency Air Quality System (EPA-AQS) surface measurements in August 2006. We present sample retrievals for locations with matching ozone sondes and show improvements in both error characteristics and vertical resolution compared to the measurements using UV or TIR alone. Examining retrieval diagnostics such as degrees of freedom for signal and averaging kernels for the multispectral retrievals, we see substantial improvement in the lowest tropospheric and total tropospheric sensitivity. Comparison with EPA-AQS's surface monitoring data indicates that multispectral observations capture the variation of ozone concentration at the lowest troposphere (surface to 700 hPa) due to the enhanced sensitivity.