Scientific Overview of Temporal Experiment for Storms and Tropical Systems (TEMPEST) Program

Tuesday, 16 December 2014
Chandrasekar V Chandra1, Steven C Reising2, Christian D Kummerow3, Susan C van den Heever2, Gaier Todd4, Sharmila Padmanabhan4, Shannon Thomas Brown4, Boon Lim4, Ziad S Haddad4, Timothy Koch4, Greg Berg5, Tristian L'Ecuyer6, Stephen J Munchak7, Zhengzhao Johnny Luo8, Sid Ahmed Boukabara9 and Christopher S Ruf10, (1)Colorado State University, 1373 Campus, Fort Collins, CO, United States, (2)Colorado State University, Fort Collins, CO, United States, (3)Colorado State Univ, Fort Collins, CO, United States, (4)NASA Jet Propulsion Laboratory, Pasadena, CA, United States, (5)Boeing Company Huntington Beach, Huntington Beach, CA, United States, (6)University of Wisconsin Madison, Madison, WI, United States, (7)NASA Goddard Space Flight Center, Greenbelt, MD, United States, (8)CUNY-NOAA CREST, New York, NY, United States, (9)NOAA NESDIS, Camp Springs, MD, United States, (10)University of Michigan, Ann Arbor, MI, United States
Over the past decade and a half, we have gained a better understanding of the role of clouds and precipitation on Earth's water cycle, energy budget and climate, from focused Earth science observational satellite missions. However, these missions provide only a snapshot at one point in time of the cloud’s development. Processes that govern cloud system development occur primarily on time scales of the order of 5-30 minutes that are generally not observable from low Earth orbiting satellites. Geostationary satellites, in contrast, have higher temporal resolution but at present are limited to visible and infrared wavelengths that observe only the tops of clouds. This observing gap was noted by the National Research Council’s Earth Science Decadal Survey in 2007.

Uncertainties in global climate models are significantly affected by processes that govern the formation and dissipation of clouds that largely control the global water and energy budgets. Current uncertainties in cloud parameterization within climate models lead to drastically different climate outcomes. With all evidence suggesting that the precipitation onset may be governed by factors such atmospheric stability, it becomes critical to have at least first-order observations globally in diverse climate regimes. Similar arguments are valid for ice processes where more efficient ice formation and precipitation have a tendency to leave fewer ice clouds behind that have different but equally important impacts on the Earth’s energy budget and resulting temperature trends.

TEMPEST is a unique program that will provide a small constellation of inexpensive CubeSats with millimeter-wave radiometers to address key science needs related to cloud and precipitation processes. Because these processes are most critical in the development of climate models that will soon run at scales that explicitly resolve clouds, the TEMPEST program will directly focus on examining, validating and improving the parameterizations currently used in cloud scale models. The time evolution of cloud and precipitation microphysics is dependent upon parameterized process rates. The outcome of TEMPEST will provide a first-order understanding of how individual assumptions in current cloud model parameterizations behave in diverse climate regimes.