Atmospheric River Climatology in Antarctica

• Main Authors: Wille, Jonathan, Favier, Vincent, Codron, Francis, Dufour, Ambroise
• 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 ), Océan et variabilité du climat (VARCLIM), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), AGU
• Format: Conference Object
• Language: English
• Published: HAL CCSD 2018
• Subjects: 3305 Climate change and variability; ATMOSPHERIC PROCESSESDE: 3339 Ocean/atmosphere interactions; ATMOSPHERIC PROCESSESDE: 3364 Synoptic-scale meteorology; ATMOSPHERIC PROCESSESDE: 1621 Cryospheric change; GLOBAL CHANGE; [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph]; Antarc*; Antarctic; Antarctica; Bellingshausen Sea; Dronning Maud Land; East Antarctica; Wilkes Land
• Online Access: https://hal.science/hal-02402511

International audience To properly understand the future Antarctic surface mass balance (SMB) requires a complete understanding of the factors that influence SMB today. Atmospheric rivers, broadly defined as a narrow yet long bands of high precipitable water, provide a sub-tropical connection to the Antarctic continent and are observed to significantly impact the affected region's SMB over short, extreme events. Over coastal Dronning Maud Land, East Antarctica, Gorodetskaya et al. (2013) observed that 4-5 atmospheric rivers contributed to 74-80% of the region's SMB during 2009 and 2011. When an atmospheric river reaches the Antarctic continent, their signature is clearly observed in increased downward longwave radiation, upward vertical motion, temperature, snowfall, surface melt, and moisture transport. Using an atmospheric river detection algorithm designed for Antarctica and applied to ERA-Interim reanalysis data, we assess the frequency of atmospheric rivers and estimate their impact on total snowfall from 1979-2017 over the Antarctic continent. We also found that atmospheric rivers are associated with positive temperature anomalies and have consequences on surface melt, like in interior locations of Adélie Land. There is a weak seasonal trend in atmospheric river activity that is location dependent like in the Wilkes Land region where maximum activity occurs in July. Whether an atmospheric river reaches the Antarctic continent is dependent on the degree of upper-level atmospheric blocking. Atmospheric rivers are associated with significant positive geopotential height anomalies across all regions of Antarctica with the highest anomalies occurring around the Amundsen-Bellingshausen Sea and Adélie Land. Our results suggest that atmospheric rivers should play a significant role in the Antarctic SMB, and that any future changes in atmospheric blocking or tropical-polar teleconnections may have significant impacts on future SMB projections.