NEW ORGANIC MOLECULES FROM ACE SATELLITE OBSERVATIONS

摘要

The primary aim of the Atmospheric ChemistryrnExperiment (ACE), an ESA third-party mission, is thernstudy of ozone chemistry in the stratosphere, howeverrnACE is capable of measuring the vertical distributionsrnof over 30 trace gases in the atmosphere, more than anyrnother satellite instrument. Profiles of new organicrnmolecules continue to be retrieved from almost ninernyears’ worth of ACE spectra, often using newrnquantitative laboratory spectroscopic measurements.rnTwo of the latest molecules to be retrieved arernacetonitrile (CH3CN) and trifluoromethane (CHF3;rnHFC-23), for which these are the first infrared satelliternremote-sensing observations. Acetonitrile is principallyrnemitted into the atmosphere from biomass burning. Thernlifetime of acetonitrile is of the order of 6 months,rnmaking this molecule a useful tracer for biomassrnburning. Trifluoromethane, which has a very longrnlifetime of 222 years, is the second most abundant HFCrnin the atmosphere, and its atmospheric concentrationrncontinues to increase.