AIRBORNE CAMPAIGN OBSERVATIONS AND ANALYSIS FOR THE CONFIGURABLE SCANNING SUBMILLIMETER-WAVE INSTRUMENT/RADIOMETER (COSSIR)

I. Adams¹, R. Kroodsma¹, J. Gong¹, S. Ringerud¹, Y. Liu², L. Milani^3,1

¹NASA Goddard Space Flight Center, ²Goddard Earth Science Technology and Research (GESTAR) II, University of Maryland – Baltimore County, ³Earth System Science Interdisciplinary Center (ESSIC), University of Maryland College Park

Submillimeter-wave radiometers are an emerging technology for monitoring weather. Early measurements from the Millimeter-wave Imaging Radiometer (MIR) captured the first observations of the water vapor transition at 325.15 GHz, and the ability to observe and quantify ice-phase clouds and precipitation was demonstrated during CRYSTAL-FACE with the first generation of CoSSIR. Subsequent campaigns with both CoSSIR and the UK Met Office’s International Sub Millimeter-wave Airborne Radiometer (ISMAR) have paved the way for the current and imminent submillimeter-wave spaceflight instruments: the Arctic Weather Satellite (AWS), the Ice Cloud Imager (ICI) on MetOp-SG B, the Polarized Submillimeter Ice cloud Radiometer (PolSIR), and the Convective Core Observations through MicrOwave Derivatives in the trOpics (C2OMODO). After recent upgrades, including a new scanning mechanism and a frequency plan comprising three bands at 325.15 GHz, three corresponding bands at 183.31 GHz, and window bands at 170 and 684 GHz, CoSSIR collected observations of winter storms during the Investigation of Microphysics and Precipitation from Atlantic Coast-Threatening Storms (IMPACTS) and deep convection associated gamma ray flashes during the Airborne Lightning Observatory for FEGS and TGFs (ALOFT), establishing the instrument as a reliable sensor for airborne science. Now, in preparation for the North American Upstream Feature-Resolving and Tropopause Uncertainty Reconnaissance Experiment (NURTURE), we are revising the CoSSIR frequency plan at 325.15 GHz to match both ICI and PolSIR and adjusting the frequency plan at 183.31 GHz to match altitude sensitivity.

To showcase the valuable science achieved with submillimeter-wave radiometry, our presentation will cover cases observed by CoSSIR during IMPACTS and ALOFT. Our team’s analysis will further demonstrate the strong relationship between submillimeter-wave brightness temperature and ice clouds. We will also provide results on the tomography experiments we have conducted using CoSSIR’s configurable scanning capability. Finally, we will discuss the new frequency plan in the context of NURTURE and CoSSIR’s sibling sensor, the Conically Scanning Millimeter-Wave Imaging Radiometer – Hyperspectral (CoSMIR-H), and in the context of the PolSIR mission.