OPERATIONAL ATMOSPHERIC CHEMISTRY MONITORING MISSIONS CAPACITY

1. OPERATIONAL ATMOSPHERIC CHEMISTRY MONITORING MISSIONSCAPACITY Summary and Recommendations Hennie Kelder, project coordinator Final presentation June 2, 2005

2. Summary • There is overwhelming evidence ,support and initatives for Earth System Monitoring and hence for continuation of atmospheric composition sounding from space, inclusive the troposphere, in an integrated approach • Sufficiently mature techniques exist to make the move from research missions to an operational system for monitoring and operational applications • Three main missing space system elements have been identified in the existing and planned operational missions: • Geometrical: spatial sampling in nadir; limb view • Spectral: nadir view using short-wave infrared (SWIR) • Temporal: diurnal variations and afternoon observations

3. Recommendations (1) • To enhance spatio-temporal sampling of the planetary boundary layer in the 2010-2020 time period and afterwards for operational Air Quality applications by a combination of space elements in Geostationary Orbit (GEO) and Low-Earth Orbit (LEO): • user needs for regional Air Quality applications in Europe are served best by frequent sampling at high horizontal resolution to include information on the diurnal variations of pollutants and to enhance the number of observations into the boundary layer • Global coverage is required for the monitoring and assessment of global Air Quality, the oxidising capacity, and the quantification of continental in/outflow. • The global (LEO) and regional (GEO) missions are of equal importance.

4. Recommendations (2) • A LEO mission with a UV-VIS-SWIR nadir viewing spectrometer with small ground pixel size and daily global coverage in an afternoon polar orbit to complement on MetOp and NPOESS observations in the post-Envisat/post-EOS-Aura time period and to maximize cloud-free sampling of the boundary layer. • A GEO mission with a UV-VIS-SWIR spectrometer with small ground pixel size to cover diurnal variations in Air Quality and to further improve upon the cloud-free sampling of the planetary boundary layer over Europe from less than once a day to a few times daily on average. • Taking into account maturity, cost and risk issues, it is recognised that a LEO mission could have a shorter lead time, even though it will only partially fulfil requirements of European Air Quality users

5. Recommendations (3) • Planned operational missions offer insufficient vertical resolution in the upper troposphere and stratosphere with respect to O3, H2O and other compounds for Stratospheric Ozone and Climate. Limb MIR and limb MM techniques are two available mature options as operational limb-sounding. • To efficiently extend the Air Quality Monitoring Mission (LEO and GEO) to include Climate Protocol Monitoring for CH4, CO emissions and aerosols by addition of SWIR channels • Given the very stringent uncertainty requirements on CO2 the implementation of operational monitoring of CO2 for emission monitoring is not recommended until useful capability has been shown by the planned OCO (NASA) and GOSAT (JAXA) research missions.

6. Recommendations (4) • For the Air Quality application in the post-EPS time frame to combine the UV-VIS-SWIR spectrometers with a high spectral resolution thermal IR sounder on the LEO and GEO platforms for: • tropospheric profiling of O3 and CO • performing measurements at day and night, and • to provide additional trace gases. • To investigate as an alternative to the combination of GEO and LEO for Air Quality in the post-EPS time frame a constellation of satellites in low inclination orbits. • To move incrementally towards an operational monitoring system for atmospheric composition, in line with the GMES overall concept.