Grantee Research Project Results
Sensitivity of Heterogeneous Atmospheric Mercury Processes to Climate Change
EPA Grant Number: R833375Title: Sensitivity of Heterogeneous Atmospheric Mercury Processes to Climate Change
Investigators: Schauer, James J. , Griffin, Robert J. , Shafer, Martin M. , Holloway, Tracey
Institution: University of Wisconsin - Madison , University of New Hampshire
EPA Project Officer: Chung, Serena
Project Period: February 15, 2007 through February 14, 2010 (Extended to February 14, 2011)
Project Amount: $899,731
RFA: Consequences of Global Change For Air Quality (2006) RFA Text | Recipients Lists
Research Category: Climate Change , Air
Objective:
The overall goal of the project is to quantify the impact of climate change on key atmospheric processes that control the fate of mercury in transport from emissions to deposition. Efforts will be directed at building on the existing scientific understanding of atmospheric mercury processes by examining the incremental impact of climate change variables on heterogeneous atmospheric mercury oxidation and depositional processes.
The goal will be realized by achieving the following objectives:
1) Quantify the sensitivity of dry deposition of elemental mercury, reactive gaseous mercury (RGM) and particulate mercury to temperature, humidity, ozone, nitrogen oxides, and sunlight intensity.
2) Quantification of sensitivity of atmospheric mercury oxidation and reduction reaction in fog and cloud water to temperature, sunlight intensity, and the composition of these atmospheric waters.
3) Investigate the oxidation of elemental mercury in the presence of the complex atmospheric reactions that produce photochemical smog and secondary organic aerosols.
4) Investigate the sensitivity of mercury deposition to climate change variables using a regional chemical transport model that will be evaluated using a year long data set of hourly speciated atmospheric mercury and event based wet deposition data.
Approach:
An integrated laboratory and modeling approach is employed, building upon laboratory based low-level atmospheric mercury experiments developed under a prior EPA STAR project. Existing research expertise is applied to the following efforts:
1) Studies of mercury cycling to plant and soil surfaces at the UW-Madison Biotron controlled environment using on-line mercury instruments and mercury isotope spiking studies.
2) Laboratory studies of the chemical transformations of mercury with cloud and fog water collected using ultra-clean sampling methods along with parallel studies using artificial cloud and fog waters.
3) Smog chamber studies of mercury oxidation during controlled ozone and SOA formation studies using expertise at the University of New Hampshire.
4) Regional chemical transport modeling to study atmospheric mercury deposition sensitivity to temperature, precipitation, and atmospheric circulation patterns associated with climate change.
Expected Results:
These efforts will result in a better understanding of impact of climate change on atmospheric mercury processes, supporting the development of strategies to control mercury deposition in the present and future. These results will help understand the broader impact of climate change.
Publications and Presentations:
Publications have been submitted on this project: View all 4 publications for this projectJournal Articles:
Journal Articles have been submitted on this project: View all 4 journal articles for this projectSupplemental Keywords:
heavy metals, air toxics, oxidation,, RFA, Air, climate change, environmental monitoringProgress and Final Reports:
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.