Circumpolar transport and air-surface exchange of atmospheric mercury at Ny-Ålesund (79° N), Svalbard, spring 2002

• Main Authors: Sommar, J., Wängberg, I., Berg, T., Gårdfeldt, K., Munthe, J., Richter, A., Urba, A., Wittrock, F., Schroeder, W. H.
• Other Authors: Department of Chemistry, University of Gothenburg (GU), Swedish Environmental Research Institute (IVL), Norwegian Institute for Air Research (NILU), Institute of Environmental Physics Bremen (IUP), University of Bremen, Ecological Spectroscopy Laboratory, Czech Academy of Sciences Prague (CAS), Meteorological Service of Canada, Environment and Climate Change Canada
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2004
• Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; Svalbard; Ny-Ålesund; Ny Ålesund
• Online Access: https://hal.science/hal-00301168; https://hal.science/hal-00301168/document; https://hal.science/hal-00301168/file/acpd-4-1727-2004.pdf

International audience Mercury in different environmental compartments has been measured at Ny-Ålesund (78°54? N, 11°53? E) during an intensive campaign, 17 April to 14 May 2002. Time-resolved speciated determination of mercury in the atmosphere and snow was conducted at the Norwegian research station at the Zeppelin mountain, 474 m above the sea level, and at the Italian research facility Dirigibile Italia, 12 m above the sea level. Total Gaseous Mercury (TGM) was present in the range <0.1 to 2.2 ng m ?3 during the campaign. Three mercury depletion events, identified as periods with decreased TGM concentrations, were observed. At the lower altitude, TGM concentrations following such events were found to exhibit both higher magnitude and larger variability in comparison to results from the Zeppelin station. Oxidised mercury species in air and fall-out with snow as well as mercury attached to particles were also measured and their concentrations were found to be anti-correlated with TGM in air. The strongest modulation was observed for total mercury concentration (Hg-tot) in snow (range 1.5?76.5 ng L ?1 ). Solid evidence for photo-stimulated emissions of Hg 0 (g) from the snow pack in conjunction to depletion events were obtained from gradient measurements as well as from flux chamber measurements. Steep diurnal concentration variations of Hg 0 (aq) in surface seawater were also found to concur with changing solar radiation. The concentration of Hg 0 (aq) in seawater was found to be in the range 12.2?70.4 pg L ?1 , which corresponds to supersaturation. Hence, the seawater surface constituted a source emitting elemental mercury. The concentrations of the transient mercury forms RGM (Reactive Gaseous Mercury) and PM (Particulate Mercury) respectively and BrO column densities detected using a zenith and off-axis sky viewing DOAS instrument were very low except for a few individual samples during the major depletion event. An evaluation of trajectories for selected events and comparisons with BrO vertical column ...