Seasonal and spatial evasion of mercury from the western Mediterranean Sea
Journal article, 2017

Continuous measurements of gaseous elemental mercury (GEM) in air and dissolved gaseous mercury (DGM) in surface seawater were performed during two oceanographic campaigns (Fenice 2011 (25/10-11/11) and Fenice 2012 (11-29/8)), carried out in the Tyrrhenian Sea (Fenice 211), western Mediterranean Sea and the Atlantic Ocean (Fenice 2012) as part of the GMOS project (Global Mercury Observation System). Measured GEM and DGM were used to estimate the air-sea exchange of elemental mercury by using a two-thin film gas exchange model. Measured GEM concentrations showed significantly higher values in fall (1.7 +/- 0.4 ng m(-3)) compared to summer (1.5 +/- 03 ng m(-3), p < 0.05) and average DGM concentrations were significantly higher during the autumn campaign (29 +/- 5 pg L-1) than during the summer campaign (22 +/- 9 pg L-1, p < 0.05). Results obtained in this study and in the literature suggest seasonal, spatial and yearly variations of GEM, DGM and calculated mercury flux rates in the western Mediterranean Sea. Calculated mercury flux rates in this study ranged from -5.6 and 34 ng m(-2) h(-1), influenced by high variability in measured DGM concentrations and wind speeds. Significantly higher average evasion rates were found in summer (5.3 +/- 5.9 ng m(-2) h(-1)) compared to autumn (3.7 +/- 4.2 ng m(-2) h(-1), p < 0.05). Taking into account spatial and seasonal variations in the western Mediterranean Sea, the annual emission of elemental mercury from the 578,000 km(2) large area was estimated to be 13 tons. (C) 2017 Elsevier B.V. All rights reserved.

Elemental Mercury

Gas exchange model

Air

Temporal Trends

GEM

Gas-Exchange

Chloralkali Plant

Dissolved Gaseous Mercury

Natural-Waters

DGM

Mediterranean Sea

Exchange

Seawater

Wind-Speed

Mercury flux

Atmospheric Mercury

Seasonal variation

Author

Michelle Nerentorp

Chalmers, Chemistry and Chemical Engineering, Energy and Material

Katarina Gårdfeldt

Chalmers, Chemistry and Chemical Engineering, Energy and Material

I. Wangberg

IVL Swedish Environmental Research Institute

Marine Chemistry

0304-4203 (ISSN)

Vol. 193 34-43

Subject Categories

Environmental Sciences

DOI

10.1016/j.marchem.2017.02.003

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Latest update

3/7/2018 1