Herman Sievering

Retired Professor
Ph.D., University of Illinois, 1971

Areas of Interest:

Atmospheric Science, Human Impacts on Ecosystems and the Earth system as a whole, exchange of atmospheric pollutants at the air-water interface (especially air-sea surface) and at air-landscape interfaces (especially air-forest ecosystem exchange)

Current Research

Global Cycling of Sulfur, funded by the National Science Foundation (NSF)

Ship and island sampling campaigns over the Atlantic Ocean and at shoreline sites in Australia and New Zealand have been a part of these studies. Future sampling will take place over the Pacific Ocean and at Korean shoreline sites. A major goal of these studies is to better understand the influence which atmospheric Sulfur aerosols have on Earth's climate system. These sampling campaigns also provide an important opportunity for student involvement in field environmental research, crucial to environmental science learning.

Pollutant Nitrogen Uptake and Distribution at Conifer Forest Areas, including the Smoky Mountains, the Harvard Forest, and CU's Mountain Research Station, funded by the U.S. EPA, the U.S. Forest Service and U.S. Dept. of Energy

One goal of these studies is to understand whether pollution Nitrogen inputs to forests are increasing tree growth, thereby enhancing Carbon storage of carbon dioxide taken up during photosynthesis. Alternatively, this pollution Nitrogen input may be causing nutrient imbalances and affecting the natural cycling of Nitrogen through the forest system, which may contribute to forest dieback.

Select Publications

Pryor, S., H. Sievering, E. Nemitz, M., Kulmala and 5 others, 2008, A review of measurement and modeling tools for quantifying particle atmosphere-surface exchange, Tellus v. 60B, 42-75.

Cainey, J., H. Sievering and G. Ayers, 2007, Where to now? A synthesis of current views of the CLAW hypothesis, Environmental Chemistry v. 4, 406-409.  

Sievering, H., J. Torizzo, and T. Tomaszewski, 2006, Canopy uptake of atmospheric nitrogen deposition at a conifer forest: photosynthesis efficiency and NEE, Tellus v. 59B, 483-492.

Sievering, H., 2000, Aerosols, in Encyclopedia of Environmental Sciences, D.E. Alexander (ed.), Chapman & August 14, 2008 H., 1999, Nitrogen deposition and Carbon storage, Nature, v. 400, 629-631.

Sievering, H., 1998, Atmospheric Chemistry and Deposition over Niwot Ridge: Relation to Alpine and Subalpine Ecology, in Ecology of Rocky Mountain Alpine Tundra, W. Bowman and T. Seastedt (eds.), Elsevier Press, NY

Sievering, H., D. Rusch, and L. Marquez, 1997, Nitric acid, particulate nitrate and ammonium in the continental free troposphere: nitrogen deposition to an alpine tundra ecosystem, Atmospheric Environment, v. 30, 2527-2538.

Sievering, H., Boatman, J., Gorman, E., Ley, T., Pszenny, A., and Kim, Y., 1996, Ozone oxidation of sulfur in sea-salt particles during the Azores Marine Aerosol and Gas Exchange Experiment, J. of Geophysical Research, v. 100, 23063-23078.

Sievering, H., Wilkinson, S., and Hicks, B., 1994, Trends in global marine cloudiness and anthropogenic sulfur, Journal of Climate, v. 4, 434-440.

Sievering, H., Boatman, J., Gorman, E., Kim, Y., Anderson, L., Ennis, G., Luria, M., and Pandis, S., 1992, Removal of sulfur from the Marine Boundary Layer by ozone oxidation in sea-salt aerosols, Nature, v. 360, 571-574.

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