On June 26, 2012, NASA cancelled the SEAC4RS mission, which was scheduled to begin in August 2012, due to the absence of necessary approvals by regional authorities in the timeframe necessary to support the mission’s planned deployment and scientific observation window.
Southeast Asia Composition, Cloud, Climate Coupling Regional Study (SEAC4RS) will take place in August and September of 2012. This deployment will address key questions regarding the influence of Asian emissions on clouds, climate, and air quality as well as fundamental satellite observability of the system. Science observations will focus specifically on the role of the Asian monsoon circulation and convective redistribution in governing upper atmospheric composition and chemistry. Satellite observations suggest a strong impact of the Asian Summer Monsoon on Tropopause Transition Layer (TTL) composition and a direct relationship to surface sources including pollution, biogenic emissions, and biomass burning. Attention will also be given to the influence of biomass burning and pollution, their temporal evolution, and ultimately impacts on meteorological processes which in turn feed back into regional air quality. With respect to meteorological feedbacks, the opportunity to examine the impact of polluting aerosols on cloud properties and ultimately dynamics will be of particular interest.
To accomplish the goals of SEAC4RS, multiple aircraft are required. The NASA DC-8 will provide observations from near the surface to 12 km, and the NASA ER-2 will provide high altitude observations reaching into the lower stratosphere as well as important remote sensing observations connecting satellites with observations from lower flying aircraft and surface sites. A critical third aircraft needed to sample convective outflow and slow ascent of air above the main convective outflow level (~12 km) has been identified as the NSF/NCAR GV (HIAPER). Participation by the GV will be through a collaboration in which the DC-8 will participate in the NSF-sponsored DC3 mission.
Basing the aircraft in Thailand is optimal for achieving science objectives with a preferred base in U-Tapao, Thailand.