Cloud Land Surface Interaction Campaign (CLASIC)

Cumulus clouds and their development are important components of the atmospheric radiation budget and water cycle of the U.S. Southern Great Plains, especially during the summer growing season.

The Cloud Land Surface Interaction Campaign (CLASIC), organized by the Department of Energy's Atmospheric Radiation Measurement program, will use the Southern Great Plains Climate Research User Facility in Oklahoma during summer 2007 to closely examine cumulus convection and associated thunderstorm formation. Both processes are strongly controlled by land surface conditions but also influence the land surface itself through rain-induced changes in soil moisture and photosynthesis. Land surface characteristics also affect the timing and evolution of cumulus convection.

Three "supersites" across Oklahoma will be heavily instrumented to obtain ground-based measurements to link observed carbon fluxes to atmospheric structure. Seven aircraft—including NASA's Twin Otter—will fly over the region at various altitudes, while satellites carrying active sensors, such NASA's CloudSat and CALIPSO, will provide spaceborne measurements of surface albedo, surface fluxes, soil moisture, vegetation indices and terrestrial hydrology.

Research will begin in earnest in June, following the winter wheat harvest when changes in land surface cover lead to large changes in the surface albedo, latent heat flux, and sensible heat flux. Data collected will allow researchers to better understand the relationship between land surface processes and observed cloud cover, and vice versa.

Ultimately, mission findings will be used to advance computer models that help scientists better understand our climate. The campaign will also help realize the potential of new instrument capabilities, provide significant validation data for NASA’s new satellite sensors, and enhance cross-disciplinary research.

Contacts:

Mark Miller
Brookhaven National Laboratory
miller@bnl.gov

Mission Website:

http://science.arm.gov/clasic/

Science Goals:

• Study the roles of cumulus convection and spatial variations in land cover in depleting low-level water vapor
• Examine the relationships between cumulus clouds and aerosols and the soil-plant-atmosphere exchange of energy, carbon, and water
• Evaluate how land cover changes impact surface energy, carbon and water fluxes, and affect local and regional cumulus cloud formation
• Determine whether land surface processes affect atmospheric aerosol loading and chemistry
• Assess the roles of plant transpiration and surface evaporation from soil in latent and sensible heat flux and cumulus cloud formation

Partners:

Scientists from the Department of Energy and several agencies and universities will participate in this campaign, including NASA, Brookhaven National Laboratory, NOAA, U.S. Department of Agriculture, Duke University, Oklahoma University, University of Illinois, University of Wisconsin, and others.

When:

June - August 2007

Where:

Oklahoma

Links:

CALIPSO satellite:
http://www.nasa.gov/mission_pages/calipso/main/index.html

CloudSat mission:
http://www.nasa.gov/mission_pages/cloudsat/main/index.html

Climate Change Science Program:
http://www.climatescience.gov/