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Elemental mercury concentrations and fluxes in the tropical atmosphere and ocean.
Environ Sci Technol. 2014 Oct 07; 48(19):11312-9.ES

Abstract

Air-sea exchange of elemental mercury (Hg(0)) is a critical component of the global biogeochemical Hg cycle. To better understand variability in atmospheric and oceanic Hg(0), we collected high-resolution measurements across large gradients in seawater temperature, salinity, and productivity in the Pacific Ocean (20°N-15°S). We modeled surface ocean Hg inputs and losses using an ocean general circulation model (MITgcm) and an atmospheric chemical transport model (GEOS-Chem). Observed surface seawater Hg(0) was much more variable than atmospheric concentrations. Peak seawater Hg(0) concentrations (∼ 130 fM) observed in the Pacific intertropical convergence zone (ITCZ) were ∼ 3-fold greater than surrounding areas (∼ 50 fM). This is similar to observations from the Atlantic Ocean. Peak evasion in the northern Pacific ITCZ was four times higher than surrounding regions and located at the intersection of high wind speeds and elevated seawater Hg(0). Modeling results show that high Hg inputs from enhanced precipitation in the ITCZ combined with the shallow ocean mixed layer in this region drive elevated seawater Hg(0) concentrations. Modeled seawater Hg(0) concentrations reproduce observed peaks in the ITCZ of both the Atlantic and Pacific Oceans but underestimate its magnitude, likely due to insufficient deep convective scavenging of oxidized Hg from the upper troposphere. Our results demonstrate the importance of scavenging of reactive mercury in the upper atmosphere driving variability in seawater Hg(0) and net Hg inputs to biologically productive regions of the tropical ocean.

Authors+Show Affiliations

Department of Environmental Health, Harvard School of Public Health , Boston, Massachusetts 02215, United States.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

Language

eng

PubMed ID

25171182

Citation

Soerensen, Anne L., et al. "Elemental Mercury Concentrations and Fluxes in the Tropical Atmosphere and Ocean." Environmental Science & Technology, vol. 48, no. 19, 2014, pp. 11312-9.
Soerensen AL, Mason RP, Balcom PH, et al. Elemental mercury concentrations and fluxes in the tropical atmosphere and ocean. Environ Sci Technol. 2014;48(19):11312-9.
Soerensen, A. L., Mason, R. P., Balcom, P. H., Jacob, D. J., Zhang, Y., Kuss, J., & Sunderland, E. M. (2014). Elemental mercury concentrations and fluxes in the tropical atmosphere and ocean. Environmental Science & Technology, 48(19), 11312-9. https://doi.org/10.1021/es503109p
Soerensen AL, et al. Elemental Mercury Concentrations and Fluxes in the Tropical Atmosphere and Ocean. Environ Sci Technol. 2014 Oct 7;48(19):11312-9. PubMed PMID: 25171182.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Elemental mercury concentrations and fluxes in the tropical atmosphere and ocean. AU - Soerensen,Anne L, AU - Mason,Robert P, AU - Balcom,Prentiss H, AU - Jacob,Daniel J, AU - Zhang,Yanxu, AU - Kuss,Joachim, AU - Sunderland,Elsie M, Y1 - 2014/09/12/ PY - 2014/8/30/entrez PY - 2014/8/30/pubmed PY - 2015/12/15/medline SP - 11312 EP - 9 JF - Environmental science & technology JO - Environ Sci Technol VL - 48 IS - 19 N2 - Air-sea exchange of elemental mercury (Hg(0)) is a critical component of the global biogeochemical Hg cycle. To better understand variability in atmospheric and oceanic Hg(0), we collected high-resolution measurements across large gradients in seawater temperature, salinity, and productivity in the Pacific Ocean (20°N-15°S). We modeled surface ocean Hg inputs and losses using an ocean general circulation model (MITgcm) and an atmospheric chemical transport model (GEOS-Chem). Observed surface seawater Hg(0) was much more variable than atmospheric concentrations. Peak seawater Hg(0) concentrations (∼ 130 fM) observed in the Pacific intertropical convergence zone (ITCZ) were ∼ 3-fold greater than surrounding areas (∼ 50 fM). This is similar to observations from the Atlantic Ocean. Peak evasion in the northern Pacific ITCZ was four times higher than surrounding regions and located at the intersection of high wind speeds and elevated seawater Hg(0). Modeling results show that high Hg inputs from enhanced precipitation in the ITCZ combined with the shallow ocean mixed layer in this region drive elevated seawater Hg(0) concentrations. Modeled seawater Hg(0) concentrations reproduce observed peaks in the ITCZ of both the Atlantic and Pacific Oceans but underestimate its magnitude, likely due to insufficient deep convective scavenging of oxidized Hg from the upper troposphere. Our results demonstrate the importance of scavenging of reactive mercury in the upper atmosphere driving variability in seawater Hg(0) and net Hg inputs to biologically productive regions of the tropical ocean. SN - 1520-5851 UR - https://www.unboundmedicine.com/medline/citation/25171182/Elemental_mercury_concentrations_and_fluxes_in_the_tropical_atmosphere_and_ocean_ L2 - https://doi.org/10.1021/es503109p DB - PRIME DP - Unbound Medicine ER -