Mike Bergin, PhDSCHOOL OF CIVIL AND ENVIRONMENTAL ENGINEERING and
SCHOOL OF EARTH AND ATMOSPHERIC SCIENCE
|
|
|
|
Research Interests: Aerosols are generated by a variety of natural and anthropogenic sources. I am interested in the processes that emit, transform and deposit particulate matter. A current focus of my research is how particles in the atmosphere directly modify the surface radiation balance of the Earth. This is of importance to the climate of the Earth, as well as plant growth and visibility. We have conducted studies at a variety of polluted urban sites as well as pristine remote sites to understand the contrast between clean and dirty locations. Another interest is the past impacts of aerosols on climate through interpretation of paleorecords archived in ice cores. My work involves a combination of lab and field studies as well as the development of relatively simple mathematical models. Some favorite projects: Click on the marked locations on the below map: 
Aerosol optical depth measured by NASA's MODIS instrument on the Terra satellite - January, 2001
The researchers sleeping area up at Summit Station on the Greenland Ice Sheet The Greenland Ice Sheet is a precious resource in the Northern Hemisphere, playing a role in regulating global climate, storing a large volume of fresh water (3000 m thick at the center of the ice sheet!), and preserving over 100,000 years of our planet's atmospheric history. Our research goal on the Greenland Ice Sheet was to study the magnitude and chemical stability of two major species that are commonly found in airborne particles: organic carbon and elemental carbon. The organic compounds are possibly important tracers of human pollution that is transported to the Greenland Ice Sheet -- possibly giving information on what types of sources are impacting the pristine Arctic environment. Elemental carbon, often also called "soot" or "black carbon", is of interest both for its linkage to combustion-related pollution and its ability to absorb sunlight. It is a concern that elemental carbon present in the air and snow on the Greenland Ice Sheet may absorb solar radiation and cause a local warming influence. To study both organic and elemental carbon, we joined with two other universities (University of New Hampshire and University of Wisconsin-Madison) in an NSF funded study to conduct field measurements during the summers of 2005 and 2006. We are currently For more on the project, please visit our project website. You can also take a photojourney from the coast of Greenland to Summit. Kevin McMahon, a teacher at Renfroe Middle School in Atlanta was with us at Summit during 2006 and you can view the online journal of his trip.
Lugging equipment to the sampling site near Niwot
Ridge, CO
The famed Star Ferry with a hazy backdrop over Hong Kong's business district The Pearl River Delta (PRD) region of China, which encompasses Hong Kong and Guangdong Province, is a highly populated and industrialized area of China. In fact it accounts for roughly 30% of all exported goods in China. Accompanying the intense growth taking place in the region is an extremely serious air quality problem. As part of a collaborative effort with our Chinese colleagues we conducted particulate sampling at several stations across the region during 2002-2003. Our focus was to determine the sources (e.g. coal burning, biomass burning, diesel and gasoline vehicles) of the haziness as well as the source regions within the PRD. More about the project can be found at our PRD Website. Also, an executive summary of the final project report is available from Hong Kong Civic Exchange. Publications from the project thus far include Hagler et al. (2006) and Hagler et al. (2007, in press).
A view of the Atlanta skyline on a hazy day Atlanta is a excellent place to study particulate matter given the many anthropogenic sources and meteorology that often favors high pollutant levels. As part of the EPA funded Supersite Study we measured a variety of aerosol chemical, physical and optical properties. Our overall goal was to characterize the climate relevant radiative properties of atmospheric aerosols in Atlanta. Not surprisingly, aerosols exert a significant direct influence on the radiation balance in and around Atlanta. The results are discussed in detail in Carrico et al. (2003). Chamonix and the Maurienne Valley, France:
A haze layer above Chamonix and a concerned Jean-Luc Jaffrezo of LGGE Grenoble Chamonix and the Maurienne valley are main roadways for transport of people and goods between France and Italy. The emissions from cars and trucks as well as from residential fires in winter generates air quality that is often unhealthy. This despite the fact that these locations have unsurpassed natural beauty. As part of the POVA project, with our involvement funded by NSF, we tested a new instrument designed to measure the size-resolved concentrations of water insoluble aerosols. Water insoluble aerosols are of importance in that they are harmful to human health and impact the ability of aerosols to take on water and hence impact the radiation balance of the atmosphere. More on our results can be found in Greenwald et al. (2006).
Mike and Jin Xu getting ready to sample at the Linan station in the YRD The Yangtze river delta (YRD), that encompasses a large region in the vicinity of Shanghai, is a major agricultural region of China. Intermingled with agricultural activites are a wide range of industries, and population centers that are significant pollution sources. The wide range of anthropogenic emissions have resulted in high levels of pollutants, such as fine particulate matter and ozone, that are harmful to human and environmental health. Our study, which was part of the NASA funded China-MAP project, focused in measuring fine particulate matter with an emphasis on the extent to which aerosols are modifying climate and crop production in the region by directly impacting the solar radiation balance. We found that aerosols have a tremendous impact on both the energy balance at the surface (Xu et al., 2002; Xu et al., 2003), as well as potentially the growth of plants (Chameides et al., 1999; Bergin et al., 2001).
A view of the Great Wall near from Zhenbeitai near the ACE-ASIA sampling station The Gobi desert is a major source of dust over much of China. In addition, dust from the Gobi has been found over much of the northern Hemisphere including Europe, North America, and Greenland. As part of the NSF funded ACE-ASIA field campaign we made measurements in Yulin, China located on the southern edge of the Gobi desert. Our objective was to measure the characteristics of desert dust near the source region. This information is important in assessing the influence of atmospheric processing on dust as it transported from the source region to downwind receptor sites. Our results are discussed in detail in Xu et al. (2004).
Kathmandu Valley from the air Radiative heating of the Himalaya are responsible to a large extent for the summer monsoon season that brings rainfall to India and its neighbors. Recent work suggests that the haze over much of the Indian subcontinent is significantly impacting the Asia monsoon by absorbing and scattering solar radiation. Our study measured the aerosol chemical composition and optical depth over a roughly one year period during 1999/2000. This time series yields a wealth of information on the seasonality of aerosol sources and source regions as well as the radiative impact of aerosols over the Himalaya. Are findings are summarized in Carrico et al. (2003). As part of a one week pilot study during June 1999 we conducted a field experiment in conjunction with Beijing University to determine aerosol chemical, physical, and optical properties in Beijing. The poor air in Beijing is from a combination of anthropogenic sources and is also influenced to a large extent by windblown dust and transport from regions outside of the greater Beijing area. More details on this study can be found in Bergin et al. (2001).
|
