Spatial distributions of trace organic species: Results from the TORERO and CONTRAST airborne campaigns with the interpretation aided by the CAM-Chem 3D chemistry climate model
Tuesday, 16 December 2014
A wide range of trace volatile organic compounds (VOCs) were measured during the Tropical Ocean Troposphere Exchange of Reactive Halogen Species and Oxygenated VOC (TORERO), and Convective Transport of Active Species in the Tropics (CONTRAST). The NCAR Trace Organic Gas Analyzer (TOGA) measured VOCs on board the NSF GV aircraft during both of these experiments. Complementary VOC measurements were made by the UM AWAS on board the GV during CONTRAST. The relatively rapid TOGA measurements (30 second data every 2 minutes) coupled with the very high sensitivity of the instrument allows for tracking signatures of pollution in an otherwise near pristine environment (CONTRAST, TORERO) and for mapping out gradients in the VOC distributions in the northern and southern hemispheres. Because of the wide range of solubilities and reactivities the suite of measured VOCs encompasses, these species provide critical information on the transport and chemical and/or physical processing during and following convective events (CONTRAST). In this study, we use the CAM-Chem 3D chemistry climate model driven with MERRA meteorological fields to provide context to our observational data. The model has a detailed representation of tropospheric and stratospheric chemistry. Its scope has recently been extended to include halogen sources, reactive halogen chemistry, and related atmospheric processes.