Chemical cycling and deposition of atmospheric mercury in polar regions: review of recent measurements and comparison with models

• Published in: Atmospheric Chemistry and Physics
• Main Authors: Angot, Hélène, Dastoor, Ashu, de Simone, Francesco, Gårdfeldt, Katarina, Gencarelli, Christian, Hedgecock, Ian, Langer, Sarka, Magand, Olivier, Mastromonaco, Michelle, Nordstrøm, Claus, Pfaffhuber, Katrine, Pirrone, Nicola, Ryjkov, Andrei, Selin, Noelle, Skov, Henrik, Song, Shaojie, Sprovieri, Francesca, Steffen, Alexandra, Toyota, Kenjiro, Travnikov, Oleg, Yang, Xin, Dommergue, Aurélien
• Other Authors: Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes 2016-2019 (UGA 2016-2019 )-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes 2016-2019 (UGA 2016-2019 ), Environment and Climate Change Canada, Institute of Atmospheric Pollution Research (IIA), Consiglio Nazionale delle Ricerche Roma (CNR), Department of Chemistry, University of Gothenburg (GU), Swedish Environmental Research Institute (IVL), National Environmental Research Institute Danmark (NERI), Norwegian Institute for Air Research (NILU), Massachusetts Institute of Technology (MIT), Air Quality Research Division Toronto, EMEP Meteorological Synthesizing Centre-West (MSC-W), European Monitoring and Evaluation Programme (EMEP), European Environment Agency (EEA)-European Environment Agency (EEA), British Antarctic Survey (BAS), Natural Environment Research Council (NERC)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2016
• Subjects: [SDE]Environmental Sciences; Antarctic; Arctic; East Antarctic Ice Sheet; Antarc*; Antarctica; Ice Sheet
• Online Access: https://hal-insu.archives-ouvertes.fr/insu-01389460; https://hal-insu.archives-ouvertes.fr/insu-01389460/document; https://hal-insu.archives-ouvertes.fr/insu-01389460/file/ATMOSPHERIC%20CHEMISTRY%20AND%20PHYSICS%20-%20Chemical%20cycling%20and%20deposition%20of%20atmospheric%20mercury%20in%20polar%20regions%20review%20of%20recent%20measurements%20and%20comparison%20with%20models.pdf; https://doi.org/10.5194/acp-16-10735-2016

International audience Mercury (Hg) is a worldwide contaminant that can cause adverse health effects to wildlife and humans. While atmospheric modeling traces the link from emissions to deposition of Hg onto environmental surfaces, large uncertainties arise from our incomplete understanding of atmospheric processes (oxidation pathways, deposition, and re-emission). Atmospheric Hg reactivity is exacerbated in high latitudes and there is still much to be learned from polar regions in terms of atmospheric processes. This paper provides a synthesis of the atmospheric Hg monitoring data available in recent years (2011–2015) in the Arctic and in Antarctica along with a comparison of these observations with numerical simulations using four cutting-edge global models. The cycle of atmospheric Hg in the Arctic and in Antarctica presents both similarities and differences. Coastal sites in the two regions are both influenced by springtime atmospheric Hg depletion events and by summertime snowpack re-emission and oceanic evasion of Hg. The cycle of atmospheric Hg differs between the two regions primarily because of their different geography. While Arctic sites are significantly influenced by northern hemispheric Hg emissions especially in winter, coastal Antarctic sites are significantly influenced by the reactivity observed on the East Antarctic ice sheet due to katabatic winds. Based on the comparison of multi-model simulations with observations, this paper discusses whether the processes that affect atmospheric Hg seasonality and interannual variability are appropriately represented in the models and identifies research gaps in our understanding of the atmospheric Hg cycling in high latitudes.