Does the early bird catch the plume?
Julia Marshall, DLR (Deutsches Zentrum für Luft- und Raumfahrt), julia.marshall@dlr.de (Presenter)
Luca Bugliaro Goggia, DLR (Deutsches Zentrum für Luft- und Raumfahrt), luca.bugliaro@dlr.de
André Butz, Heidelberg University, andre.butz@iup.uni-heidelberg.depatrick.joeckel@dlr.de
Klaus-Dirk Gottschaldt, DLR (Deutsches Zentrum für Luft- und Raumfahrt), klaus-dirk.gottschaldt@dlr.de
Patrick Jöckel, DLR (Deutsches Zentrum für Luft- und Raumfahrt), patrick.joeckel@dlr.de
Bastian Kern, DLR (Deutsches Zentrum für Luft- und Raumfahrt), bastian.kern@dlr.de
Anke Roiger, DLR (Deutsches Zentrum für Luft- und Raumfahrt), anke.roiger@dlr.de
A number of current and upcoming missions are targeting the plumes resulting from large point sources of greenhouse gases in order to monitor anthropogenic emissions from space. These include different measurements strategies that can be roughly divided into wide-swath pushbroom imagers (like CO2M or TROPOMI) and targeted approaches (such as OCO-3's snapshot mode, GHGSat, MethaneSAT, or CO2Image). Common to these missions is the need to capture optimally cloud-free scenes of "well-behaved", i.e. easy to interpret, plumes.
This raises the question of how the observation strategy can be adapted to maximize the number of good scenes. One aspect of this is the overpass time. For passive sensors the sunlight dependence places a clear constraint of a few hours on either side of local solar noon, but within this window there may be some opportunity for optimization. Most current missions in sun-synchronous low-earth orbit have daytime overpasses close to 13:00 local time but both experience from flight campaigns and comparison of MODIS cloud cover from Aqua and Terra suggest that an earlier overpass time may result in more cloud-free scenes. On the other hand, earlier overpass times run the risk of a less established planetary boundary layer, with a residual layer confounding the interpretation of the total column measurements.
This study addresses this question in the context of the CO2Image mission concept: a high-resolution imager to be flown within the DLR CompactSatellite program, targeting facility-scale emissions down to source strengths of 1 MtCO2/year. (For more information on CO2Image, see the overview presentation by Butz et al.) The problem is considered from multiple perspectives: an analysis of diurnal cloud cover relying on geostationary cloud imagers, the diurnal development of urban plumes from large-eddy simulations over Indianapolis, and an assessment of the impact of land-sea-breeze circulation for CO2 plumes from sources near the coast. Retrieved OCO-3 scenes measured in snapshot mode are analyzed as a function of local time as well. The assessment aims to objectively weight the benefit and drawbacks of different overpass times in the context of the CO2Image mission.
Poster: Poster_Marshall_0_126_25.pdf
Presentation Type: Poster
Session: 1.2b Results expected from future missions
Session Date: Monday (6/14) 9:45 AM