Summary: Effect of clouds on the calculated vertical distribution
of shortwave absorption in the tropics
Sally A. McFarlane,1
James H. Mather,1
Thomas P. Ackerman,2
and Zheng Liu3
Received 5 December 2007; revised 29 May 2008; accepted 26 June 2008; published 23 September 2008.
 High vertical resolution profiles of cloud properties were obtained from cloud radars
operated by the Atmospheric Radiation Measurement (ARM) program on the islands of
Nauru and Manus in the Tropical Western Pacific (TWP). Broadband flux calculations
using a correlated k-distribution model were performed to estimate the effect of clouds on
the total column and vertical distribution of shortwave absorption at these tropical sites.
Sensitivity studies were performed to examine the role of precipitable water vapor,
cloud vertical location, optical depth, and particle size on the shortwave (SW) column
absorption. On average, observed clouds had little impact on the calculated total SW
column absorption at the two sites, but a significant impact on the vertical distribution of
SW absorption. Differences in the column amount, vertical profiles, and diurnal cycle of
SW absorption at the two sites were due primarily to differences in cirrus cloud frequency.
Citation: McFarlane, S. A., J. H. Mather, T. P. Ackerman, and Z. Liu (2008), Effect of clouds on the calculated vertical distribution
of shortwave absorption in the tropics, J. Geophys. Res., 113, D18203, doi:10.1029/2008JD009791.