HR: 14:30h
AN: A53B-03    [Abstracts]
TI: Sensitivity of AOT calculation to relative humidity
AU: * Bian, H
EM: bian@code916.gsfc.nasa.gov
AF: UMBC Goddard Earth Science and Technology Center, NASA Goddard Space Flight Center, mail stop 613.3, Greenbelt, MD 20771, United States
AU: Chin, M
EM: chin@code916.gsfc.nasa.gov
AF: NASA Goddard Space Flight Center, NASA Goddard Space Flight Center, mail stop 613.3, Greenbelt, MD 20771, United States
AU: Rodriguez, J
EM: jrodriguez@pop600.gsfc.nasa.gov
AF: NASA Goddard Space Flight Center, NASA Goddard Space Flight Center, mail stop 613.3, Greenbelt, MD 20771, United States
AU: Strahan, S
EM: sstrahan@pop600.gsfc.nasa.gov
AF: UMBC Goddard Earth Science and Technology Center, NASA Goddard Space Flight Center, mail stop 613.3, Greenbelt, MD 20771, United States
AB: The importance of relative humidity (RH) on aerosol optical thickness (AOT) is strongly amplified in a nearly water vapor-saturated atmosphere because mass extinction efficiency (MEE) of hygroscopic aerosols increases very rapidly under these conditions. The RH-MEE relationship presents a challenge for AOT calculation because at high RH (>90%) there is a large range of MEE possible for a given RH, and a small change in RH creates very large uncertainty in MEE. In this work, we present a sensitivity experiment that explores the AOT uncertainty in a global chemistry transport model simulation that is derived from the representation of RH used in the AOT calculation. We will particularly focus on the following questions: 1. What is the optimal time step for the AOT calculation in terms of RH variation over high RH regions? 2. Where and when is the AOT most sensitive to changes in RH?
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
DE: 4801 Aerosols (0305, 4906)
DE: 4906 Aerosols (0305, 4801)
SC: Atmospheric Sciences [A]
MN: 2007 Joint Assembly