Title: Enabling Observations of Temperature and Humidity Profiles and Cloud Ice Particle Size Distribution in the Upper-Troposphere/Lower-Stratosphere from 6U-Class Satellites: Tropospheric Water and Cloud ICE (TWICE)
Presenting Author: Steven C. Reising
Organization: Colorado State University
Co-Author(s): Pekka Kangaslahti, Erich Schlecht, Jonathan Jiang, Xavier Bosch-Lluis, Mehmet Ogut, Yuriy Goncharenko, Braxton Kilmer, Sharmila Padmanabhan, Richard Cofield, Nacer Chahat, Shannon T. Brown, William Deal, Alex Zamora, Kevin Leong, Sean Shih, and Gerry Mei

Abstract:
Ice clouds cover more than 33% of Earth’s surface and play a significant role in the hydrological cycle by affecting atmospheric dynamics, precipitation and cloud processes. Global measurements of cloud ice particle size distribution and total ice water content, along with associated temperature and water vapor profiles, in the upper troposphere/lower stratosphere (UTLS) are critically needed to improve knowledge of the role of ice clouds in Earth’s climate, precipitation and cloud processes. Such observations will enable improvement in cloud and moisture models including precipitation forecasting. Measurements at a range of frequencies in the millimeter- and submillimeter-wave frequency range provide sensitivity to ice particle size distribution in the range of tens to hundreds of micrometers. To perform such observations on a global basis, a new millimeter- and submillimeter-wave instrument is currently under development with suitable mass, power and volume to be deployed on 6U-Class nanosatellites. The Tropospheric Water and Cloud ICE (TWICE) instrument is a wide-band millimeter- and sub-millimeter wave radiometer measuring at 15 frequencies from 118 GHz to 670 GHz. The TWICE instrument is designed to provide observations of upper tropospheric water vapor and ice particle size distribution in clouds on a global basis at a variety of local times. TWICE will use 25-nm InP High Electron Mobility Transistor (HEMT) low-noise amplifier-based (LNA) receiver front-ends to provide low-noise and low-power operation in a small form factor at millimeter- and sub-millimeter-wave frequencies. TWICE radiometers will perform end-to-end calibration once each conical scan by viewing both cold space (2.7 K) and an ambient calibration target at a known thermodynamic temperature. TWICE will meet the requirements for operation in a 6U-Class satellite (6U CubeSat) with dimensions of 34 cm x 20 cm x 10 cm and mass up to 12 kg.