This project involves the measurement of a wide range of organic trace gases collected from the HAIS Advanced Whole Air Sampler (AWAS) on the NCAR GV aircraft as part of the Convective Transport of Active Species in the Tropics (CONTRAST) experiment proposed to take place during January and February 2014 from the island of Guam. CONTRAST is designed to measure the chemistry and transport of reactive chemical species into the tropical Tropopause Transition Layer (TTL) over the Western Pacific warm pool area. The trace gases to be measured consist of a range of organic molecules, including a both short-lived and long-lived halocarbon compounds, as well as non-methane hydrocarbons, organic nitrates, and selected sulfur species. These gases will provide information to diagnose halogen transformations and budget of the TTL, to estimate relative age of air in the UT/LS, and to distinguish air mass sources in the region.
The sources, chemistry, and transport of trace gases and their degradation products into the lower stratosphere in the tropical Pacific during the boreal winter season can substantially impact the chemistry of the lower stratosphere. This project will improve process-oriented chemistry/climate models and their validation by providing a unique suite of benchmark measurements, especially in the characterization of active halogen chemistry.
