The Polarized Submillimeter Ice-Cloud Radiometer (PolSIR): Observing the diurnal cycle of ice clouds in the tropics and sub-tropics
- 1Vanderbilt University, Earth & Environmental Sciences, Nashville, United States of America (ralf.bennartz@vanderbilt.edu)
- *A full list of authors appears at the end of the abstract
The Polarized Submillimeter Ice-Cloud Radiometer (PolSIR): Observing the diurnal cycle of ice clouds in the tropics and sub-tropics
In May 2023 NASA has selected PolSIR as the latest addition to its Earth Venture Instrument class missions. PolSIR addresses key research priorities related to uncertainties in our current understanding in high clouds and cloud feedbacks as formulated in NASA’s latest Decadal Survey and in the latest Intergovernmental Panel on Climate Change (IPCC) Assessment. In this context, PolSIR will address the following objectives:
- Constrain the seasonally influenced diurnal cycle amplitude, form, and timing of the ice water path (IWP) and particle diameter in tropical and sub-tropical ice clouds
- Determine the diurnal variability of ice clouds in the convective outflow areas and understand relation to deep convection
- Determine the relationship between shortwave and longwave radiative fluxes and the diurnal variability of ice clouds
- Enable improvement of climate models by providing novel observations of the diurnal cycle of ice clouds, ultimately leading to improved climate modeling skills and increased fidelity of climate forecasts in support of critical decision-making.
The PolSIR mission consists of two 12U CubeSats, each equipped with a cross-track scanning polarized submillimeter radiometer in the spectral range of 325–680 GHz. The two PolSIR satellites fly in separate, 52-degree inclination, non-sun-synchronous orbits, taking science measurements between ±35 degrees latitude enabling monthly sampling of the diurnal cycle of ice clouds and their microphysical properties in the tropics and sub-tropics. PolSIR’s observation concept provides significant benefits over the Program of Record (PoR) as well as synergies with future missions which will either be in sun-synchronous orbits, thus not sampling the diurnal cycle, or lack the observation frequencies needed to fully observe ice water path (IWP).
Ralf Bennartz1, Dong Wu2, Ian Adams2, Donifan Barahona2, Emily Berndt3, Helene Brogniez4, Negar Ehsan2, Greg Elsaesser5,6, Jie Gong2, Ben Johnson7, Bryan Karpowicz8, Rachael Kroodsma2,9, Daniel Loveless10, Aronne Merrelli11, Claire Pettersen11, Paul Racette2, Anita D. Rapp12, Chris Vanags1, 1: Vanderbilt University 2: NASA GSFC 3: NASA MSFC 4: Paris Saclay University 5: Columbia University 6: NASA GISS 7: UCAR 8: GMAO 9: University of Maryland, College Park 10: Indiana University 11: University of Michigan 12: Texas A&M University
How to cite: Bennartz, R. and Wu, D. and the PolSIR Science Team: The Polarized Submillimeter Ice-Cloud Radiometer (PolSIR): Observing the diurnal cycle of ice clouds in the tropics and sub-tropics, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-5886, https://doi.org/10.5194/egusphere-egu24-5886, 2024.
