Shortwave Forcing by Shallow Cumuli over the Southern Great Plains
Abstract
Shallow cumuli are ubiquitous over large areas of the globe, including both the interior of continents and the trade wind regions over the oceans. Measurements made at the Atmospheric Radiation Measurement (ARM) Climate Research Facility (ACRF) Southern Great Plains site provide a unique long-term data set that can be used to investigate the influence that these clouds have on the shortwave energy budget at a continental location. Using data collected for the summers of 2000 through 2007, inclusive, over 900 hours with fair- weather cumuli were identified using data from a cloud radar, lidar, ceilometer and Total Sky Imager. The ARM Shortwave Flux Analysis data product was used to determine the shortwave forcing on a range of time scales. This work shows that the hourly-average shortwave forcing is on the order of -60 W m-2. When the data is adjusted to account for times without shallow clouds, the shortwave forcing over the entire summer (defined as May through August) is still significant, -2 W m-2. Additional analysis provides insight into the annual variability of the forcing, as well as examining the frequency of positive shortwave forcing.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2008
- Bibcode:
- 2008AGUFM.A11D0165M
- Keywords:
-
- 0321 Cloud/radiation interaction