C014-0017
Wideband Microwave Radiometry for the Retrieval of Arctic Sea Ice Physical Properties in the MOSAiC Campaign

Tuesday, 8 December 2020
Poster
Oguz Demir1, Mark Andrews2, Kenneth Ayotte3, Kenneth C Jezek4, Gunnar Spreen5, Stefan Hendricks6, Julienne Stroeve7, Marcus Huntemann5, Rasmus T Tonboe8, Vishnu Nandan9, Lars Kaleschke6 and Joel T Johnson2, (1)Ohio State University Main Campus, Department of Electrical and Computer Engineering, Columbus, OH, United States, (2)Ohio State University Main Campus, Department of Electrical and Computer Enginneering, Columbus, OH, United States, (3)Ohio State University Main Campus, ElectroScience Laboratory, Columbus, OH, United States, (4)Byrd Polar and Climate Research Center, The Ohio State University, Columbus, OH, United States, (5)University of Bremen, Bremen, Germany, (6)Alfred Wegener Institute Helmholtz-Center for Polar and Marine Research Bremerhaven, Bremerhaven, Germany, (7)University College London, London, United Kingdom, (8)Danish Meteorological Institute, Copenhagen, Denmark, (9)University of Manitoba, Winnipeg, MB, Canada
Abstract:
Microwave radiometry has been used by the SMAP and SMOS missions for remotely sensing the thickness of sea ice. However, the maximum thickness sensitivity of these L-band systems is limited to 1 m or less due to limits on the penetration through sea ice of the 1.4 GHz signals used. The Ultra-Wideband Microwave Radiometer (UWBRAD) was developed to extend this thickness limit by monitoring ice microwave emissions over a wider spectrum of 0.5 – 2 GHz. The UWBRAD utilizes advanced RFI detection and mitigation to enable its operation outside the protected 1400-1427 MHz frequency band.

A four channel UWBRAD (540, 900, 1380, 1740 MHz) was deployed on an Arctic sea ice floe in December 2019 as a part of the MOSAiC expedition (www.mosaic-expedition.org). The radiometer was designed to observe ice emissions continuously from a stationary mast at an oblique angle. The instrument periodically performed observations of the sky to assist with radiometric calibration.

Sea ice thickness retrievals are performed by matchups with a forward model that predicts sea ice brightness temperatures as a function of thickness, salinity, temperature, and snow cover properties. The forward model describes sea ice as a multilayer structure of snow, ice and ocean. The radiative transfer equations are applied to predict emissions for the oblique angles at which the instrument was operated during the campaign. The forward model also incorporates the effects of the antenna beam pattern. As a first step toward ice property retrievals, ice properties from in-situ measurements were used in the model to compare forward model predictions with observed brightness temperatures.

The meaningful correlation between model predictions and measurements obtained demonstrates that the simultaneous retrieval of multiple ice parameters such as ice thickness, ice salinity, and even the average ice temperature should be feasible. These results confirm the utility of wideband 0.5-2 GHz brightness temperature measurements for the remote sensing of sea ice properties.

Data used in this manuscript was produced as part of the international Multidisciplinary drifting Observatory for the Study of the Arctic Climate (MOSAiC) with the tag MOSAiC20192020. The project ID is AWI_PS122_00.

<< Previous Abstract | Next Abstract >>