Optimal configuration of a far-infrared radiometer to the study the Arctic winter atmosphere

• Published in: Journal of Geophysical Research: Atmospheres
• Main Authors: Coursol, Laurence, Libois, Quentin, Gauthier, Pierre, Blanchet, Jean-Pierre
• Other Authors: Centre ESCER, Université du Québec à Montréal = University of Québec in Montréal (UQAM), Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2020
• Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; [SDU.STU.ME]Sciences of the Universe [physics]/Earth Sciences/Meteorology; polar night
• Online Access: https://hal.science/hal-03080133; https://hal.science/hal-03080133/document; https://hal.science/hal-03080133/file/Preprint_Final.pdf; https://doi.org/10.1029/2019JD031773

International audience Several FIR satellite missions are planned for the next decade, with a special interest for the Arctic region. A theoretical study is performed to help about the design of a FIR radiometer, whose configuration in terms of channels number and frequencies is optimized based on information content analysis. The problem is cast in a context of vertical column experiments (1D) to determine the optimal configuration of a FIR radiometer to study the Arctic polar night. If only observations of the FIR radiometer were assimilated, the results show that for humidity, 90 % of the total information content is obtained with 4 bands whereas for temperature 10 bands are needed. When the FIR measurements are assimilated on top of those from the Advanced Infrared Sounder (AIRS), the former bring in additional information between the surface and 850 hPa and from 550 hPa to 250 hPa for humidity. Moreover, between 400 hPa and 200 hPa, the FIR radiometer is better than AIRS at reducing the analysis error variance for humidity. This indicates the potential of FIR observations for improving water vapor analysis in the Arctic.