Atmospheric mercury speciation dynamics at the high-altitude Pic du Midi Observatory, southern France

• Main Authors: Fu, X., Marusczak, N., Heimbürger-Boavida, Lars-Eric, Sauvage, B., Gheusi, F., Prestbo, E., Sonke, E.
• Other Authors: IRT Saint Exupéry - Institut de Recherche Technologique, Institut méditerranéen d'océanologie (MIO), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'aérologie (LAERO), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-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)-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), Tekran Research and Development
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2016
• Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; Arctic; North Atlantic
• Online Access: https://hal.science/hal-02163095; https://hal.science/hal-02163095/document; https://hal.science/hal-02163095/file/acp-2015-842.pdf; https://doi.org/10.5194/acp-2015-842

International audience Continuous measurements of atmospheric gaseous elemental mercury (GEM), 16 particulate bound mercury (PBM) and gaseous oxidized mercury (GOM) at the high-altitude Pic 17 du Midi Observatory (PDM, 2877 m a.s.l) in southern France were made from Nov 2011 to Nov 18 2012. The mean GEM, PBM and GOM concentrations were 1.86 ng m-3, 14 pg m-3 and 27 pg m-3, 19 respectively and we observed 44 high PBM (up to 98 pg m-3) and 61 high GOM (up to 295 pg m-3) 20 events. The high PBM events occurred mainly in cold seasons (winter and spring) whereas high 21 GOM events were mainly observed in the warm seasons (summer and autumn). In cold seasons 22 the maximum air mass residence times (ARTs) associated with high PBM events were observed in 23 the upper troposphere over North America. The ratios of high PBM ARTs to total ARTs over North 24 America, Europe, the Arctic region and Atlantic Ocean were all elevated in the cold season 25 compared to the warm season, indicating that the middle and upper free troposphere of the 26 Northern Hemisphere may be more enriched in PBM in cold seasons. PBM concentrations and 27 PBM/GOM ratios during the high PBM events were significantly anti-correlated with atmospheric 28 aerosol concentrations, air temperature and solar radiation, suggesting in situ formation of PBM in 29 the middle and upper troposphere. We identified two distinct types of high GOM events with the 30 GOM concentrations positively and negatively correlated with atmospheric ozone concentrations, 31 respectively. High GOM events positively correlated with ozone were mainly related to air masses 32 from the upper troposphere over the Arctic region and middle troposphere over the temperate 33 North Atlantic Ocean, whereas high GOM events anti-correlated with ozone were mainly related 34 to air masses from the lower free troposphere over the subtropical North Atlantic Ocean. The 35 ARTs analysis demonstrates that the lower and middle free troposphere over the North Atlantic 36 Ocean was the largest source ...