Scientists Convene at SGP Site for Complex Convective Cloud Experiment

Published: 31 May 2010

In early May, scientists involved in the Midlatitude Continental Convective Cloud Experiment (MC3E), a joint field program involving NASA Global Precipitation Measurement Program and ARM investigators, held their first onsite planning meeting to begin pinpointing the details for this major effort. Planned for April–May 2011 at the ARM Southern Great Plains site, the campaign is highly complex, involving five remote radiosonde sites, supplemental radars, coordinated aircraft, and a dense network of dozens of rain gauges and disdrometers. By heavily supplementing the routine measurements from the SGP site, the goal of MC3E is to provide the most complete characterization of convective cloud systems and their environment that has ever been obtained, providing details for the representation of cumulus clouds in computer models that have never before been available.

Gathering at the SGP site for the first day of the meeting, they reviewed the site’s capabilities and additional equipment required for the campaign, focusing mainly on radar system operations. These include the existing ARM radars, the new ARM radar systems to be deployed later this year through the American Recovery and Reinvestment Act of 2009, and several additional NASA radar systems to be deployed for the campaign. They discussed siting logistics, scanning strategies, and how to best use all the systems together to accomplish the science goals of the campaign. The day ended with a visit to the future site of one of the ARM X-band radar systems that will play an important role in observing storm-scale dynamics during MC3E.

The next day, the group met in nearby Ponca City to further refine plans for the experiment. Discussions focused on the details and logistics of the radiosonde array and planning for aircraft instrumentation and operations. This included finalizing locations for radiosonde launch sites and staffing these sites, locations for aircraft weather briefings, and flight plans and updates on the aircraft instrument payloads. For purposes of personnel safety in the field, they also initiated a plan for forecasting the presence of the convective storms—the target of MC3E operations—and more severe weather events.

Prior to this meeting, NASA technicians visited the SGP site to scout out locations for a network of 20–40 rain gauges and approximately 25 disdrometers. A list of candidate sites was prepared, all located within approximately 10 kilometers of the SGP Central Facility. This dense network is designed to give important information on the variability of rain rates and rain drop-size distributions on the spatial scale of a space-based precipitation radar footprint. Testing of the instruments for this network is currently underway while leases with local landowners are being worked out.