Science objectives of EOS-Aura's Ozone Monitoring Instrument (OMI)

The Ozone Monitoring Instrument (OMI) will fly on NASA's satellite EOS-Aura, which is scheduled for launch in June 2003. The EOS-Aura satellite is focussed on atmospheric chemistry and climate issues. The main science objectives of the EOS-Aura mission are: (I) Is the ozone layer recovering as expected? (II) What are the sources of tropospheric pollutants, their chemical transformation and their transport? (III) What are the roles of upper-tropospheric water vapor, aerosols and ozone in climate change? The EOS-Aura satellite consists of 4 instruments, which are the Microwave Limb Sounder (MLS), the High Resolution Dynamics Limb Sounder (HIRDLS), the Tropospheric Emission Spectrometer (TES), which is a nadir and limb sounder, and OMI. OMI is a UV/VIS nadir solar backscatter spectrograph, which reaches global coverage in one day with a 13 × 24 km² footprint. OMI is derived from the European satellite instruments GOME and SCIAMACHY. OMI is capable of measuring (ir)radiances of the sun and earth in the wavelength range of 270 to 500 nm, from which ozone column and profile, NO₂, SO ₂ and BrO as well as aerosols, cloud coverage and cloud top pressure can be derived. OCIO and HCHO are in principle also possible data products of OMI. OMI's unique capability in measuring column amounts of ozone, NO ₂ etc. with a small footprint and daily global coverage will enable EOS-Aura to monitor tropospheric pollution on a regional scale. The design and capability of OMI will be explained. The contribution of OMI to answer the above mentioned science questions and the resulting science requirements of the instrument will be discussed.