HR: 1340h
AN: A53C-1340    [Abstracts]
TI: Does the Madden-Julian Oscillation Influence Aerosol Variability?
AU: * Tian, B
EM: baijun.tian@jpl.nasa.gov
AF: Jet Propulsion Laboratory, California Institute of Technology, M/S 183-501 4800 Oak Grove Drive, Pasadena, CA 91109, United States
AU: Waliser, D E
EM: duane.waliser@jpl.nasa.gov
AF: Jet Propulsion Laboratory, California Institute of Technology, M/S 183-501 4800 Oak Grove Drive, Pasadena, CA 91109, United States
AU: Kahn, R A
EM: ralph.kahn@jpl.nasa.gov
AF: Jet Propulsion Laboratory, California Institute of Technology, M/S 183-501 4800 Oak Grove Drive, Pasadena, CA 91109, United States
AU: Li, Q
EM: qinbin.li@jpl.nasa.gov
AF: Jet Propulsion Laboratory, California Institute of Technology, M/S 183-501 4800 Oak Grove Drive, Pasadena, CA 91109, United States
AU: Yung, Y L
EM: yly@gps.caltech.edu
AF: Division of Geological and Planetary Sciences, California Institute of Technology, MC 170- 25 1200 E. California Blvd., Pasadena, CA 91125, United States
AU: Tyranowski, T
EM: tom@gps.caltech.edu
AF: Division of Geological and Planetary Sciences, California Institute of Technology, MC 170- 25 1200 E. California Blvd., Pasadena, CA 91125, United States
AU: Geogdzhayev, I V
EM: ipor@giss.nasa.gov
AF: NASA Goddard Institute for Space Studies, 2880 Broadway, New York, NY 10025, United States
AU: Mishchenko, M I
EM: mmishchenko@giss.nasa.gov
AF: NASA Goddard Institute for Space Studies, 2880 Broadway, New York, NY 10025, United States
AU: Torres, O
EM: torres@qhearts.gsfc.nasa.gov
AF: Joint Center for Earth Systems Technology, University of Maryland Baltimore County, Suite 320 5523 Research Park Drive, Baltimore, MD 21228, United States
AU: Smirnov, A
EM: asmirnov@aeronet.gsfc.nasa.gov
AF: Goddard Earth Sciences & Technology Center, University of Maryland Baltimore County, Suite 320 5523 Research Park Drive, Baltimore, MA 21228, United States
AB: We investigate the modulation of aerosols by the Madden-Julian Oscillation (MJO) using satellite-based global aerosol products, including aerosol index (AI) from the Total Ozone Mapping Spectrometer (TOMS) on Nimbus-7, and aerosol optical thickness (AOT) from the Moderate Resolution Imaging Spectroradiometer (MODIS) on Terra and Aqua and the Advanced Very High Resolution Radiometer (AVHRR) on NOAA satellites. A composite analysis is performed for boreal winter, and the global pentad rainfall data from the NOAA Climate Prediction Center (CPC) Merged Analysis of Precipitation (CMAP) are used to identify MJO events. The MJO composites exhibit large variations in the TOMS AI and MODIS/AVHRR AOT over the equatorial Indian and western Pacific Oceans where MJO convection is active, as well as the tropical Africa and Atlantic Ocean where MJO convection is relatively weak but the background aerosol level is relatively high. A strong inverse linear relationship between the TOMS AI and rainfall anomalies, but a weaker, less coherent positive correlation between the MODIS/AVHRR AOT and rainfall anomalies, were found. The Aerosol Robotic Network AOT pattern at Kaashidoo (73.5°E, 4.9°N) and Nauru (167°E, 0.5°S) is more consistent with MODIS and AVHRR. These results indicate a connection between the MJO, its associated rainfall and circulation variability, and the observed aerosol variations. Several physical and non-physical factors that may contribute to the observed aerosol-rainfall relationship, such as aerosol humidification effect, wet deposition, surface wind speed, phytoplankton, different sensor sensitivities (absorbing versus non-absorbing aerosols and upper versus lower tropospheric aerosols), sampling issue, and cloud contamination, are discussed. However, a clear causal explanation for the observed patterns remains elusive. Further investigation is needed to unravel this complex aerosol-rainfall relationship.
DE: 0365 Troposphere: composition and chemistry
DE: 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
DE: 1620 Climate dynamics (0429, 3309)
DE: 1640 Remote sensing (1855)
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting