CloudSat made a nighttime overpass (approximately 0630 UTC) of the thunderstorms responsible for the tornadic outbreak over Kentucky, Tennessee, and Mississippi on Tuesday, 5 Februrary 2008. This extensive tornado outbreak, which is responsible for more than 50 fatalities and billions of dollars in damage, occurred in the late evening and throughout the night of the 5th into the 6th of February.

The upper image is a nighttime color infrared image from GOES with an overlay of CloudSat's descending track. CloudSat transited the region from north to south, and captured the convective outbreaks over Kentucky and Tennessee, then observed the convection over eastern Mississippi. The lower image combines CloudSat QuickLook images from segments 28 and 29 taken from CloudSat granule number 9450. The intensity of the convection is particularly evident in the CloudSat image - large regions of radar attenuation are seen (represented by a lack of surface signal return in the radar image) as well as evidence of multiple scattering (seen in the radar image as a sub-surface return) due to the large hail present in these systems.

Storm reports from this outbreak are available online from NOAA-SPC: http://www.spc.noaa.gov/climo/reports/080205_rpts.html

CloudSat is providing unique information about recent storms in Texas and Oklahoma (see CNN coverage of Texas flooding here). The images above were taken at 2000 UTC (3:00 PM CDT) on 26 June 2007. In the first image an obvious storm hangs over the middle of the United States. The second image is CloudSat data looking, in profile, at the clouds in this storm. The vertical axis represents the altitude from the ground to the top of the atmosphere. The variations of color intensity are differences in reflectivity and an indication of the differing amounts of water and ice in the storm clouds. The bright line at the bottom of the panel is the ground return from the radar. This indicates that the radar penetrated to the ground most of the time, even through heavy rainfall. Where the ground return disappears is an indication that the radar was attenuated by heavy precipitation, likely exceeding 30 mm/hr, based on previous studies. From one side to the other, the bottom panel is approximately 800 km, and the vertical scale from top to bottom is approximately 30 km. The CloudSat data provide analysts and forecasters with a view of storms never before available. Cross-sections like these provide a view of the internal structure of these storms, giving information about the intensity, rainfall rates, and cloud organization.

CloudSat's Cloud Profiling Radar collected a number of cross-sectional profiles of recent heavy tropical rains over China's southern coast. During the week of 4-11 June 2007, large areas on and near China's southern coast received up to 200 mm (8 inches) of rain, with some areas topping 500 mm (20 inches). (See article and rain map at NASA's Earth Observatory. The three images above (click to enlarge) show the evolution of the rain and cloud field, with the CloudSat ground track overlain on infrared satellite imagery on the left, together with a CloudSat Quicklook image (corresponding to the green segment of the displayed ground track) on the right. CloudSat Quicklook images are available here. The images show daytime segments of the orbit on 4, 9, and 11 June, with the satellite traveling northwest along the track on each day (right to left in the quicklook image). The coastline is marked by the transition of the topography plot from blue to brown (just above the text in the quicklook images).

CloudSat's Cloud Profiling Radar captured a profile across Tropical Storm Andrea on Wednesday, 9 May 2007 near the SC/GA/FL Atlantic coast. The upper image shows an infrared view of TS Andrea from the MODIS instrument on the Aqua satellite, with CloudSat's ground track from 0718-0720 UTC (3:18-3:20 EDT) shown as a red line. The lower image is the vertical cross section of radar reflectivity along this path, where the colors indicate the intensity of the reflected radar energy. CloudSat orbits approximately one minute behind Aqua in a satellite formation known as the A-Train. [Images courtesy of the Naval Research Laboratory-Monterey]

CloudSat is an experimental satellite that uses radar to observe clouds and precipitation from space. CloudSat orbits in formation as part of the A-Train constellation of satellites (Aqua, CloudSat, CALIPSO, PARASOL, and Aura).

Orbital elements (two-line elements or TLEs) for CloudSat are available here (CloudSat DPC). CloudSat ground tracks may be predicted using tools located on this NASA LaRC page. Orbital elements at the LaRC page are updated regularly, but use the DPC link for the very latest TLEs.

For an overview document (PDF) of science and research themes, click here. The BAMS 2002 article (PDF) describing the CloudSat mission is available here.