Environmental Sciences Ph.D. Program

Katlin Bowman wins presentation award and scholarship

First year Ph.D. student, Katlin Bowman, who is advised by Chad Hammerschmidt in the Department of Earth and Environmental Sciences, won the outstanding student presentation award at the 2012 Ocean Sciences Meeting in Salt Lake City, Utah. Her presentation, entitled “Distribution of mercury across a major ocean basin: Results from the U.S. GEOTRACES North Atlantic Zonal section” was coauthored with Dr. Hammerschmidt and Carl Lamborg of the Woods Hole Oceanographic Institution. An abstract is below. In addition, Katlin was recently awarded a $2500 scholarship from the Great Lakes National Scholarship Program for her Ph.D. studies at Wright State University.

Congratulations to Katlin!

Mercury (Hg) speciation measurements were performed on board the R/V Knorr during the U.S. GEOTRACES North Atlantic Zonal section, a two-part cruise from Lisbon, Portugal to Praia, Cape Verde (2010) and from Woods Hole, Massachusetts to Sao Vicente, Cape Verde (2011). All four principal mercury species (monomethylmercury, dimethylmercury, elemental Hg and total Hg) were determined in high vertical and horizontal resolution through areas of upwelling, high atmospheric dust deposition, low-nutrient concentrations and over a hydrothermal vent field. Preliminary results suggest that in the northeast Atlantic, total Hg has both scavenging and nutrient-type distributions. Elemental Hg, in contrast, has strong nutrient like profiles along the west coast of Africa with deep water concentrations as much as 50% of total Hg. Elemental Hg distribution, however, begins to change moving away from the continent and towards open-ocean water. Monomethylmercury distributions have pronounced mid-water maxima associated with the oxygen minimum zone. Increased levels in the oxygen minimum likely result from either in situ methylation or isopycnal transport from the margin. High-quality speciation results from the international GEOTRACES program are important to understand the global distribution and cycling of Hg.