ACPD Atmospheric Chemistry and Physics Discussions ACPD 1680-7375 Copernicus GmbH Göttingen, Germany 10.5194/acpd-11-31159-2011 Satellite climatology of cloud liquid water path over the Southeast Pacific between 2002 and 2009 O'Neill L. W. 1 3 Wang S. 2 Jiang Q. 2 Naval Research Laboratory/National Research Council, Monterey, CA, USA Marine Meteorology Division, Naval Research Laboratory, Monterey, CA, USA now at: College of Oceanic and Atmospheric Sciences, Oregon State University, Corvallis, OR, USA 25 11 2011 11 11 31159 31206 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.atmos-chem-phys-discuss.net/11/31159/2011/acpd-11-31159-2011.html The full text article is available as a PDF file from http://www.atmos-chem-phys-discuss.net/11/31159/2011/acpd-11-31159-2011.pdf

Spatial and temporal variability of liquid water path (LWP) over the southeast Pacific is described using LWP observations made by four satellite microwave radiometers (Advanced Microwave Scanning Radiometer on EOS-Aqua (AMSR-E), Tropical Rainfall Measuring Mission Microwave Imager (TMI), and the Special Sensor Microwave Imager (SSM/I) F13 and F15 satellites) for the 7-yr period June 2002–May 2009. This study quantifies seasonal and interannual variability of the LWP and LWP diurnal and semi-diurnal cycles at 30-day intervals during the 7-yr analysis period. The LWP field shows considerable spatial and seasonal variability throughout the southeast Pacific, particularly associated with the southern branch of the Intertropical Convergence Zone (SITCZ) and the Southeast Pacific Convergence Zone (SPCZ). Two distinct annual cycles of LWP are apparent, both of which peak during the austral autumn. One is associated with an active phase of the SITCZ, while the other is associated with increased LWP in the SITCZ, SPCZ, and near coastal zones, and decreased LWP elsewhere. Consistent with previous observations, the LWP diurnal cycle peaks during the early morning and has the largest amplitude in a broad region near 85° W, 20° S. The amplitude of the LWP diurnal cycle exhibits a strong annual cycle which peaks during the austral summer. A secondary annual cycle in the LWP diurnal cycle amplitude peaks during the austral autumn south of 20° S and is a minimum within a zonal band between 8° S and 20° S. Finally, although this satellite combination barely resolves semi-diurnal LWP variability, it is shown that a statistically significant semi-diurnal cycle of LWP occurs off Peru and northern Chile, consistent with previous analyses. The amplitude of the LWP semidiurnal cycle tends to peak during the austral spring.

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