Thursday, August 19, 2010
Writer: Becky Stines
UT Space Institute Participates in Gulf of Mexico NOAA Atmospheric Mercury Study
In late summer 2010, The University of Tennessee Space Institute (UTSI) participated in an intensive field study to investigate the chemistry, transport, and deposition of mercury compounds in the atmosphere. Partners in this study included the National Oceanic and Atmospheric Administration’s (NOAA) Air Resources Laboratory (ARL), the Georgia Institute of Technology, Florida State University, the University of Miami, the Canaan Valley Institute, West Virginia, Florida A&M University, the Mississippi Department of Environmental Quality, NOAA’s National Centers for Coastal Ocean Science (NCCOS), and the UT Space Institute.
Scientists and engineers converged on the Grand Bay National Estuarine Research Reserve (NERR) in Moss Point, MS where they could take advantage of the existing NOAA ARL mercury measurement facility. Specifically, the scientists measured the mercury in the atmosphere, in specific rainfall episodes, and in dew to determine the origin of the measured compounds. The role played by halogen species (bromine and chlorine) in the marine environment as well as in the upper atmosphere was also investigated using a variety of techniques.
In partnership with NOAA ARL and the University of Miami, the UTSI Aviation Systems Piper Navajo airborne science research aircraft (N11UT) was used in the study to measure mercury and other pollutants at altitudes ranging from the 500 feet above the ocean surface to 15,500 feet in the Gulf of Mexico region. These airborne measurements of mercury are somewhat unique and ground breaking, as it is only the second or third time that these types of airborne measurements have ever been made. The UTSI aircraft was based at Trent-Lott International Airport, Pascagoula, MS during the study. Dr. Phil Swartzendruber, University of Miami atmospheric mercury scientist, flew with UTSI aircrews, making the airborne measurements of mercury. To support the aircraft measurements, NOAA/ARL scientists, Winston Luke and Paul Kelly, launched weather balloons from the NERR to measure the profiles of temperature, humidity, pressure, winds, and ozone concentrations from the surface to altitudes as high as 100,000 feet. Grand Bay NERR, Florida A&M University, and NOAA NCCOS scientists also measured mercury concentrations in biota and in water and sediment samples at various locations within the reserve.
Dr. Robert Moore, CEO for UT Space Institute is very intrigued with this on-going study. The joint effort of National Oceanic and Atmospheric Administration’s (NOAA) Air Resources Laboratory (ARL), the Georgia Institute of Technology, Florida State University, the University of Miami, the Canaan Valley Institute, West Virginia, Florida A&M University, the Mississippi Department of Environmental Quality, NOAA’s National Centers for Coastal Ocean Science (NCCOS), and the UT Space Institute lends itself to future opportunities/studies into atmospheric research. He says, “Stephen Corda is an asset to our Aviation Systems program in the research he brings and the solid program he oversees. I look forward to the compilation of data and future outcome.”
In most locations, mercury in aquatic ecosystems results from deposition from the atmosphere, but the mercury in the atmosphere arises from both natural and man-made sources. Data show that the Gulf of Mexico region is plagued by persistently high total mercury in precipitation. Once in the watershed, this mercury can enter the local
food chain. Human exposure to mercury is primarily from the consumption of contaminated fish and other aquatic organisms. Fish consumption in coastal areas is typically much higher than the national average, and every state along the Gulf of Mexico has widespread fish consumption advisories for mercury.
The study is intended to allow the scientists to better understand what is unique about the region and to address questions, such as: Are mercury concentrations high because of halogens in the marine boundary layer? Or, are mercury concentrations high because frequent and widespread convective activity and rainfall continually scrub the middle and upper troposphere of reactive gaseous mercury, which may arise from halogen chemistry in the troposphere and the stratosphere? What role is played by local and regional anthropogenic mercury sources? Also, address key issues in atmospheric mercury research including the importance of transport from the middle atmosphere to the surface; the role of halogen compounds in mercury transformations; the specific chemical identities of individual mercury species; the relative contributions of natural and anthropogenic (man-made) emissions sources; and the relationship between mercury concentrations in the air and in rainfall to the prevalence of mercury in the NERR ecosystem, including fish and other wildlife.