Temporal Experiment for Storms and Tropical Systems (TEMPEST) CubeSat Constellation

Tuesday, 16 December 2014: 10:44 AM
Steven C Reising1, Gaier Todd2, Sharmila Padmanabhan2, Shannon Thomas Brown2, Boon Lim2, Christian D Kummerow1, Chandrasekar V Chandra1, Susan C van den Heever1, Tristan S L'Ecuyer3, Zhengzhao Johnny Luo4, Ziad S Haddad2, Stephen J Munchak5, Christopher S Ruf6, Greg Berg7, Timothy Koch2 and Sid Ahmed Boukabara8, (1)Colorado State University, Fort Collins, CO, United States, (2)NASA Jet Propulsion Laboratory, Pasadena, CA, United States, (3)University of Wisconsin Madison, Madison, WI, United States, (4)City College of New York, New York, NY, United States, (5)NASA Goddard Space Flight Center, Greenbelt, MD, United States, (6)University of Michigan, Ann Arbor, MI, United States, (7)Boeing Company Huntington Beach, Huntington Beach, CA, United States, (8)NOAA NESDIS, Camp Springs, MD, United States
TEMPEST addresses key science needs related to cloud and precipitation processes using a constellation of five CubeSats with identical five-frequency millimeter-wave radiometers spaced 5-10 minutes apart in orbit. The deployment of CubeSat constellations on satellite launches of opportunity allows Earth system observations to be accomplished with greater robustness, shorter repeat times and at a small fraction of the cost of typical Earth Science missions. The current suite of Earth-observing satellites is capable of measuring precipitation parameters using radar or radiometric observations. However, these low Earth-orbiting satellites provide only a snapshot of each storm, due to their repeat-pass times of many hours to days. With typical convective events lasting 1-2 hours, it is highly unlikely that the time evolution of clouds through the onset of precipitation will be observed with current assets.

The TEMPEST CubeSat constellation directly observes the time evolution of clouds and identifies changes in time to detect the moment of the onset of precipitation. The TEMPEST millimeter-wave radiometers penetrate into the cloud to directly observe changes as the cloud begins to precipitate or ice accumulates inside the storm. The evolution of ice formation in clouds is important for climate prediction because it largely drives Earth’s radiation budget. TEMPEST improves understanding of cloud processes and helps to constrain one of the largest sources of uncertainty in climate models.

TEMPEST provides observations at five millimeter-wave frequencies from 90 to 183 GHz using a single compact instrument that is well suited for a 6U CubeSat architecture and fits well within the NASA CubeSat Launch Initiative (CSLI) capabilities. Five identical CubeSats deployed in the same orbital plane with 5-10 minute spacing at 390-450 km altitude and 50-65 degree inclination capture 3 million observations of precipitation, including 100,000 deep convective events in a one-year mission. TEMPEST provides critical information on the time evolution of cloud and precipitation microphysics, thereby yielding a first-order understanding of how assumptions in current cloud-model parameterizations behave in diverse climate regimes.