Open AccessInfluence of surface snow properties on a 89 GHz brightness temperature extreme event at Dome Fuji, Antarctica
Author(s) -
Claudio Stefanini,
Giovanni Macelloni,
Marion Leduc-Leballeur,
Ghislain Picard
Publication year - 2024
Publication title -
ieee geoscience and remote sensing letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.372
H-Index - 114
eISSN - 1558-0571
pISSN - 1545-598X
DOI - 10.1109/lgrs.2024.3367111
Subject(s) - geoscience , power, energy and industry applications , communication, networking and broadcast technologies , components, circuits, devices and systems , computing and processing , signal processing and analysis
Microwave brightness temperatures observed in Antarctica at 89 GHz from the Advanced Microwave Sounding Unit B (AMSU-B) point out an exceptional decrease of 57K at Dome Fuji (77.31° S, 39.70° E) during the 2019-2020 summer. The grain size index based on 89 and 150GHz from AMSU-B and independent observations at 89 GHz from the Advanced Microwave Scanning Radiometer 2 (AMSR-2) also show concurrent unusual values. To explain such event, a theoretical analysis was carried out by means of a radiative transfer model. We explore the sensitivity of brightness temperature to surface snow properties focusing on December, just before the decrease, and April, at its end. Results confirm that this variation is mainly related to an increase in snow grain size. A decrease in snow density is also involved as suggested by the increase in brightness temperature at 1.4 GHz from Soil Moisture and Ocean Salinity (SMOS) and in the polarization ratio at 36GHz from AMSR-2. Extreme values observed at multiple frequencies, as well as peculiar atmospheric conditions explored in a previous study, confirm the uniqueness of this event at least on decennial scale.