13 January 2011
CSD scientist Sean Davis is a coauthor on a paper that has won a 2010 Alan Berman Research Publication Award at the Naval Research Laboratory. The award recognizes the best publications from each Division within NRL.
The paper titled "Directly Measured heating rates of a tropical subvisible cirrus cloud" was authored by Anthony Bucholtz (NRL), Dennis L. Hlavka (Science Systems and Applications), Matthew J. McGill (NASA Goddard), K. Sebastian Schmidt (University of Colorado), Peter Pilewskie (University of Colorado), Sean M. Davis (NOAA ESRL CSD), Elizabeth A. Reid (NRL), and Annette L. Walker (NRL). It appeared in volume 115 of the Journal of Geophysical Research in 2010.
Davis will receive a certificate and will be invited to the Alan Berman Research Publication Award Dinner on March 25 in Washington, DC.
Bucholtz, A., D.L. Hlavka, M.J. McGill, K.S. Schmidt, P. Pilewskie, S.M. Davis, E.A. Reid, and A.L. Walker, Directly measured heating rates of a tropical subvisible cirrus cloud, Journal of Geophysical Research, doi:10.1029/2009JD013128, 2010.
We present the first direct measurements of the infrared and solar heating rates of a tropical subvisible cirrus (SVC) cloud sampled off the east coast of Nicaragua on 25 July 2007 by the NASA ER-2 aircraft during the Tropical Composition, Cloud and Climate Coupling Experiment (TC4). On this day a persistent thin cirrus layer, with mostly clear skies underneath, was detected in real time by the cloud lidar on the ER-2, and the aircraft was directed to profile down through the SVC. Measurements of the net broadband infrared irradiance and spectrally integrated solar irradiance above, below, and through the SVC are used to determine the infrared and solar heating rates of the cloud. The lidar measurements show that the variable SVC layer was located between ~13 and 15 km. Its midvisible optical depth varied from 0.01 to 0.10 with a mean of 0.034 ± 0.033. Its depolarization ratio was approximately 0.4, indicative of ice clouds. From the divergence of the measured net irradiances the infrared heating rate of the SVC was determined to be ~2.50–3.24 K d-1 and the solar heating rate was found to be negligible. These values are consistent with previous indirect observations of other SVC and with model-generated heating rates of SVC with similar optical depths. This study illustrates the utility and potential of the profiling sampling strategy employed here. A more fully instrumented high-altitude aircraft that also included in situ cloud and aerosol probes would provide a comprehensive data set for characterizing both the radiative and microphysical properties of these ubiquitous tropical clouds.