Atmospheric Chemistry Program Seminar

OMI and TROPOMI: towards high resolution Air Quality and Emission monitoring by Pieternel Levelt,
KNMI and University of Technology Delft
"The Ozone Monitoring Instrument (OMI), launched on board of NASA’s EOS-Aura spacecraft on July 15, 2004, provides unique contributions to air quality monitoring from Space. The combination of urban scale resolution (13 x 24 km 2 in nadir) and daily global coverage proved to be key features for the air quality community. The OMI data is currently used operationally for improving the air quality forecasts, for inverting high-resolution emission maps, UV forecast and volcanic plume warning systems for aviation. Due to its almost 14 year continuous operation OMI provides the longest NO2 and SO2 record from space, which is essential to understand the changes to emissions globally.
In 2017 Tropospheric Monitoring Instrument (TROPOMI), was launched on board ESA’s Sentinel 5 Precursor satellite in October 2017. TROPOMI has a spatial resolution of 3,5x7 km2 in nadir; a more than 12 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 will continue OMI’s ozone and air quality trace gas records. Added to that TROPOMI will measure the O2 A band for better cloud detection, as well as CO and the second most important greenhouse gas CH4. TROPOMI will therefore be an important satellite mission for the EU Copernicus atmosphere service and will be followed by ESA’s sentinel 4 and 5 satellites. The first measurements of TROPOMI turn out to be above expectation.
In the coming decades air pollution in megacities will continue to be a major area of concern and the need for timely, high resolution information on emissions will increase, preferably to a level where sources can be isolated on the < 1 x 1 km2 scale. Currently we are working on new follow-on satellite instrumentation with which we envisage to improve emission monitoring to the < 1 x 1 km2 spatial resolution level (TROPOLITE).
An overview of air quality applications, emission inventories, and trend analyses will be given, based on the excellent OMI data record, followed by first measurements and results of the TROPOMI instrument. An outlook will be presented on the potentials of the TROPOMI and what new satellite instrumentation with a 1 x 1 km2 spatial resolution can bring in the air quality and climate domain."