MIDLATCLOUD

Midlatitude Continental Convective Clouds Experiment (MC3E)

22 April 2011 - 6 June 2011

Lead Scientist: Michael Jensen

Observatory: SGP

Convective processes play a critical role in the Earth's energy balance through the redistribution of heat and moisture in the atmosphere and their link to the hydrological cycle. Accurate representation of convective processes in numerical models is vital towards improving current and future simulations of Earth’s climate system. Despite improvements in computing power, current operational weather and global climate models are unable to resolve the natural temporal and spatial scales important to convective processes and therefore must turn to parameterization schemes to represent these processes. In turn, parameterization schemes in cloud-resolving models need to be evaluated for their generality and application to a variety of atmospheric conditions. Data from field campaigns with appropriate forcing descriptors have been traditionally used by modelers for evaluating and improving parameterization schemes. To this end, the Midlatitude Continental Convective Cloud Experiment (MC3E), a joint field program involving NASA Global Precipitation Measurement Program and ARM investigators, was conducted in south-central Oklahoma during the April to May 2011 period. The experiment leveraged from the unprecedented observing infrastructure available in the central United States, combined with an extensive sounding array. Our goal was to provide the most complete characterization of convective cloud systems and their environment that had ever been obtained, providing constraints for model cumulus parameterizations that had never before been available. Several different components of convective processes tangible to the convective parameterization problem were targeted, such as pre-convective environment and convective initiation, updraft/downdraft dynamics, condensate transport and detrainment, precipitation and cloud microphysics, influence on the environment and radiation, and a detailed description of the large-scale forcing. This intensive observation period used a new multi-scale observing strategy with the participation of a network of distributed sensors (both passive and active). The approach was to document in 3D not only precipitation, but also clouds, winds, and moisture in an attempt to provide a holistic view of convective clouds and their feedback with the environment. A goal was to measure cloud and precipitation transitions and environmental quantities that are important for convective parameterization in large-scale models and cloud-resolving model simulations. With unprecedented observing capabilities comes a greater responsibility to develop synthesis data products suitable for model studies and evaluation. Thus, special emphasis was given to the development of a systematic dialogue with the ASR modeling group for the development of such 3D data products. This experiment seeks to use a multi-scale, multi-frequency, multi-platform observational strategy to provide unprecedented detail in characterizing convection and its environment, providing constraints for model cumulus parameterizations and spaceborne measurements of precipitation over land that have never before been available. The key goals are to:

Advance the understanding of the different components of convective simulation and microphysical parameterization
Improve the fidelity of rainfall estimates over land