Elemental and reactive gaseous mercury deposition and diurnal cycles over terrestrial environments

The atmospheric component of the global biogeochemical mercury cycle was studied to determine the mechanisms behind diurnal trends and amplitudes in elemental and reactive gaseous mercury concentrations over terrestrial environments. This analysis was done using the 3D GEOS-Chem chemical transport model and the creation of a simple one-box model. Mercury is a significant neurotoxin for humans and other species that has been addressed in the policy realm on both national and international levels. Being able to model atmospheric mercury processes correctly is an important part of regulation and policy drafting. GEOS-Chem model results were compared with Weiss-Penzias et al. [2009] measurements for three Nevada, USA sites. The magnitude of elemental mercury concentrations differed by 0.07-0.2 ng/m3 , with GEOS-Chem underestimating concentrations due to an under-representation of mercury emissions at naturally enriched sites. The amplitude of reactive gaseous mercury diurnal variations differed by a factor of 3-4, with GEOS-Chem underestimating the diurnal trend. Based on the diurnal nature of this error, it is hypothesized that GEOS-Chem under represents the magnitude of elemental mercury emissions, the amount of oxidation occurring in the atmosphere, and the scale of entrainment from the free troposphere.

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2011

Author dc:creator

• Maheras, Anastasia Francis

Advisor dc:contributor.advisor

• Noelle E. Selin.

• Earth, Atmospheric, and Planetary Sciences.

Statement dc:rights

• MIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/114365

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/114365