Air Quality Applications Based on Space Observations: The Role of the 11 Years OMI Data Record and the Potentials for TROPOMI

Abstract:

In the last three decades the capabilities of measuring the atmospheric composition from space did grow tremendously with ESA’s ENVISAT and NASA’s Eos-Aura satellite programmes. The potential to operationally monitor the atmospheric composition, like the meteorological community is doing for the physical parameters, is now within reach. At the same time, the importance for society of operational environmental monitoring, related to the ozone layer, air quality and climate change, became apparent.

The Ozone Monitoring Instrument (OMI), launched on board of NASA’s EOS-Aura spacecraft in on July 15, 2004, provides unique contributions to air quality monitoring from Space. The combination of urban scale resolution (13 x 24 km² in nadir) and daily global coverage proved to be key features for the air quality community. The OMI data is currently used for improving the air quality forecasts, for inverting high-resolution emission maps, for UV forecast and for volcanic plume warning systems for aviation. Due to its 11 year continuous operation OMI now provides the longest NO₂ record from space, which is essential to understand the changes in emissions globally.

In 2016 Tropospheric Monitoring Instrument (TROPOMI), will be launched on board ESA’s Sentinel 5 Precursor satellite. TROPOMI will have a spatial resolution of 7x7 km² in nadir; a more than 6 times improvement over OMI. The high spatial resolution serves two goals: (1) emissions sources can be detected with even better accuracy and (2) the number of cloud-free ground pixels will increase substantially. TROPOMI also adds additional spectral bands that allow for better cloud corrections, as well as the retrieval of carbon monoxide and methane. TROPOMI will be an important satellite mission for the Copernicus atmosphere service.

TROPOMI will play a key role in the Air Quality Constellation, being the polar instruments that can link the 3 GEO UVN instruments, Sentinel 4, TEMPO and GEMS. Thus, TROPOMI can serve as a travelling standard that allows intercomparison of the calibration of the geostationary instruments.

An overview of air quality applications, emission inversions and trend analyses will be presented, based on the 11 years of OMI data. An outlook will be presented on the potentials of TROPOMI, including its role in the Air Quality Constellation.