Office of Biological and Environmental Research Weekly Report

February 2, 2009

ARM Data Used to Evaluate Advanced Climate Modeling Framework. Scientists in DOE’s Atmospheric Radiation Measurement (ARM) program evaluated the diurnal cycle of predicted deep clouds and differences in their behavior over land and sea using the Multi-scale Modeling Framework (MMF). The MMF is a new climate modeling tool with an ability to resolve clouds and convection at their native spatial scales in global climate models (GCMs). Preliminary results indicate that precipitation and upper-atmospheric humidity predicted by the MMF are closer to long-term ARM observations and satellite data than values predicted by standard GCMs. However, MMF does have difficulty representing the complete diurnal evolution of deep clouds due to excessive (spurious) high-altitude clouds. The frequency of deep clouds over the ocean predicted by MMF is greater than the frequency observed by satellite data and ARM studies which show that intense deep convection is more often found over land than over oceans. These results provide guidance to the next generation of improvements for MMF.

Reference:

Zhang, Y., S. A. Klein, C. Liu, B. Tian, R. Marchand, J. Haynes, R. McCoy, Y. Zhang, and T. P. Ackerman, 2008: On the diurnal cycle of deep convection, high clouds and the upper troposphere water vapor in the Multi-scale Modeling Framework. J. Geophys. Res., 113, D16105, doi:10.1029/2008JD009905.

Media Interest: No

Contact: Kiran Alapaty, SC-23.1, (301) 903-3175