Improving the Representationof Low-level Marine Clouds in Climate Models


Scientists in the DOE Atmospheric Radiation Measurement (ARM) Program developed a “fix” or an approach for climate models enabling these models to more accurately simulate low level clouds that occur over oceans. These clouds are poorly simulated in present generation of climate models because the delicate interactions among several climate processes are missing in the present models. This new approach greatly improves our confidence in the model’s ability to represent the impact of these clouds on climate change. The methodology is based on a combination of ground based ARM data as well as satellite data that revealed the physical processes controlling seasonal variation of low-altitude marine clouds. Because of their shallowness, previous studies have not been able to pinpoint the seasonal characteristics of these clouds. Though these clouds are shallow in thickness, they are abundant in water content and as a result can strongly regulate the energy budget of the earth system.


Lin W, M Zhang, and N Loeb. 2009. “Seasonal variation of the physical properties of marine boundary layer clouds off the California coast.” Journal of Climate, 22, doi:10.1175/2008JCLI2478.1.