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United States Department of Agriculture

Agricultural Research Service

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SGP Cloud and Land Surface interaction Campaign


Land Surface States and Fluxes



Cumulus convection is an important component of the atmospheric radiation budget and hydrologic cycle of the Southern Great Plains (SGP) region of the U.S., particularly during the summertime growing season. Continental cumulus convection is strongly modulated by land surface conditions; while at the same time influencing the land surface through rain- induced changes in soil moisture and through its impact on photosynthesis. Land surface conditions determine whether the partitioning of surface available energy is dominated by the sensible heat flux or by the latent heat flux, which is an important factor in the evolution of the convective boundary layer. Consequently, land surface characteristics can influence the timing and evolution of cumulus convection, in particular the cloud base height, cloud depth, and convective available potential energy.


A project called Cloud and Land Surface Interaction Campaign (CLASIC) will be conducted in this region to better understand these issues. This was initiated by the Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) proposal led by Mark Miller. This is a broad project that focuses on the ARM Climate Research Facility (ACRF) located in the Southern Great Plains (SGP) of the U.S. It will include an Intensive Observing Period (IOP) that will cover a period of several months centering on June 2007. The purpose of this IOP is to advance our understanding of cumulus convection and its controls, particularly those associated with land surface processes. The study period will straddle the winter wheat harvest when dramatic changes in the land surface occur that could lead to large changes in the surface albedo, latent heat flux, and sensible heat flux.


The CLASIC Land Team was formed from interested groups and will attempt to characterize land surface states and fluxes throughout the IOP. These include surface soil moisture, water and energy fluxes, carbon flux, surface temperature, land cover and vegetation indices. These will be provided through a combination of insitu, aircraft and satellite observations.


Current Version of the Experiment Plan for CLASIC Land can be found HERE


The Official CLASIC Webpage



Last Modified: 12/13/2016
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