Impact of recent climate change in the Arctic on snow physical parameters retrieval using SAR data (Svalbard)

• Main Authors: Dedieu, Jean-Pierre, Negrello, Charlène, Jacobi, Hans-Werner, Baladima, Foteini, Duguay, Yannick, Bernard, Eric, Boike, Julia, Gallet, Jean-Charles, Westermann, Sebastian, Wendleder, Anna
• Other Authors: Institut des Géosciences de l’Environnement (IGE), Institut de Recherche pour le Développement (IRD)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes 2016-2019 (UGA 2016-2019 ), Laboratoire Géomatique et foncier (GeF), Conservatoire National des Arts et Métiers CNAM (CNAM), HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)-HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM), Centre de géomatique du Québec (CGQ), Cegep de chicoutimi, Théoriser et modéliser pour aménager (UMR 6049) (ThéMA), Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté COMUE (UBFC)-Université Bourgogne Franche-Comté COMUE (UBFC), Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung = Alfred Wegener Institute for Polar and Marine Research = Institut Alfred-Wegener pour la recherche polaire et marine (AWI), Helmholtz-Gemeinschaft = Helmholtz Association, Norwegian Polar Institute, Department of Geosciences Oslo, Faculty of Mathematics and Natural Sciences Oslo, University of Oslo (UiO)-University of Oslo (UiO), Deutsches Zentrum für Luft- und Raumfahrt Oberpfaffenhofen-Wessling (DLR)
• Format: Conference Object
• Language: English
• Published: HAL CCSD 2019
• Subjects: [SHS.GEO]Humanities and Social Sciences/Geography; [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology; [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph]; Arctic; Norway; Ny-Ålesund; Svalbard; Climate change; Ny Ålesund; polar night
• Online Access: https://hal.science/hal-02158032

International audience Arctic snow cover dynamics exhibit strong changes in terms of extent and duration due to recent climate changeconditions (Mudryk et al., 2018; Lemke & Jacobi, 2011). In this context, innovative observation methods arehelpful for a better comprehension of the role of the snow for climate research and hydrology. The spatialvariability of snow properties is here addressed for the Ny-Ålesund area, Svalbard (N 78◦55’ / E 11◦55’) usingsatellite radar images in the X-band. This remote sensing method removes the limitations and ambiguities ofoptical imaging limited by the polar night and cloud cover.This study contributes to the “Precip-A2” project (OSUG@2020, Grenoble, France), focusing on snow and itsinteraction with the atmosphere: chemistry, radiative processes, and precipitation. One sub-task of the projectis dedicated to X-band active radar measurements (SAR) to retrieve physical properties of arctic snow (spatialvariability, depth estimation), involving consistent ground network including a large international partnership(France, Germany, Norway, Italy).1. Climatology context: for Ny-Alesund area, a change in the occurrence frequency of source region of air masseshas been identified. Consequently, an increase in temperature and water vapour content was detected (Dahlkeand Maturilli, 2016). Temperature time series since 1969 were analyzed and an increase in annual temperature of∼0.07 C per year was found. This increase is mainly driven by a positive seasonal trend in winter (DJF); thus,influencing the fraction of annual precipitation falling as snow / rain.2. Remote sensing application: a set of ten SAR images was provided by the DLR during winter 2017 from theTerraSAR-X sensor (3.1 cm, 9.6 GHz) in dual co-pol HH, VV (2.5 m resolution). Descending and ascending orbitswere combined at 35-38◦incidence angles to avoid topographic constraints. The data were processed with theESA “SNAP” toolbox. Output products: non-polarimetric analysis providing regular snow mapping from Marchto June 2017 ...