Photochemical Modeling in Support of CONTRAST (CONvective TRansport of Active Species in the Tropics)

University Of Maryland, College Park, College Park MD

Investigators

Abstract

This project is an important part of the Convective Transport of Active Species in the Tropics (CONTRAST) experiment scheduled for January and February 2014, with NSF/NCAR GV flights based out of the island of Guam. This effort includes flight planning and photochemical modeling to provide near real time interpretation of data during the campaign, and post-mission modeling and data interpretation afterward. 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 sources, chemistry, and transport of trace gases and their degradation products into the lower stratosphere in this region during the boreal winter season can substantially impact the chemistry of the lower stratosphere. The CONTRAST mission is organized in collaboration with two partner projects: ATTREX (the Airborne Tropical Tropopause Experiment--a NASA project utilizing the high altitude Global Hawk (GH), and CAST (Coordinated Airborne Studies of the Tropics)--a project sponsored by the British National Environment Research Council using a BAe-146 aircraft. The research objectives of CONTRAST are to: (1) Characterize the chemical composition at the level of convective outflow over the Western Pacific during the deep convective season; (2) Evaluate the budget of organic and inorganic bromine and iodine in the TTL; and (3) Investigate transport pathways from the oceanic surface to the tropopause. The results of this effort will increase understanding of halogen budgets and impacts on stratospheric ozone depletion. It will also improve the development of process-oriented chemistry/climate models and their validation.