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Meet the Geological Sciences Faculty!

September 2012

PROFESSOR AMANDA LYNCH

Amanda Lynch obtained her Ph.D. in Meteorology in 1993 from the University of Melbourne. From 1992-2003 she was in the United States, most recently at the University of Colorado. She was a Fellow of the NOAA Cooperative Institute for Research in Environmental Science, a Visiting Scientist at the National Center for Atmospheric Research (NCAR), and a consultant to Los Alamos National Laboratory. She returned to Australia in 2004 to take up a Federation Fellowship and head the Monash University Climate program. She was admitted as a Fellow of the Australian Academy of Technological Sciences and Engineering in 2008, and returned to the U.S. in 2011.

Lynch's interests lie in the application of climate and meteorological research to concrete problems of policy relevance. Her approaches include regional and global climate models of the contemporary and past climates, weather prediction models, statistical models, and quantitative and qualitative analysis. She has a strong interest in working with under-represented minorities, particularly indigenous people.

CURRENT RESEARCH:

The Murray-Darling Basin, which incorporates Australia's three longest rivers, covers 14% of the country's total area, and spans four States and one Territory. It is centrally important for an agricultural industry worth more than $9 billion per annum (around 40% of Australia’s agricultural GDP). The Basin is home to almost 11% of Australia's population but accounts for more than 52% of Australia’s water consumption, primarily for irrigated agriculture and hydroelectricity. All forms of irrigated agriculture have been actively encouraged throughout most of the 20th century by State governments in the form of land grants and subsidized infrastructure.

Persistent severe drought and extreme flooding episodes have presented new challenges in the region. The exceptionally wet conditions experienced in eastern Australia since the break of the “Millenium Drought” (1998 - 2010) beg the question as to whether the probability of key drought and flood characteristics (extent, severity, frequency) are changing due to human-induced climate change. 

The rivers are suffering from degradation, over-allocation, fire, drought and flood, but debates on sustainability often end in the streets or the courts. Indigenous ways of knowing can facilitate mutual respect and improved decisions. Through collaboration with the Yorta Yorta people, a team led by Amanda Lynch is conducting cultural and ecological data collection, integrated mapping and analysis, and detailed climate and economic modeling, to achieve better outcomes for rivers and residents alike.

 

August 2012

JOUKOWSKY FAMILY ASSISTANT PROFESSOR MEREDITH HASTINGS

Meredith Hastings graduated magna cum laude in 1998 with a B.Sc. in marine science and chemistry from the University of Miami in Coral Gables, FL. After a one-year stint working at the National Oceanic and Atmospheric Administration's Geophysical Fluid Dynamics Laboratory, she began graduate school in the Department of Geosciences at Princeton University. Graduating with a Ph.D. in 2004, she subsequently became a postdoctoral researcher at the University of Washington with a fellowship from the Joint Institute for Study of the Atmosphere and Ocean (JISAO). Meredith joined the faculty at Brown in 2008 in Geological Sciences and the Environmental Change Initiative, pursuing her varied research interests in the global N cycle, the biogeochemical record in ice cores, and global connections between atmospheric chemistry and climate. Professor Hastings teaches courses on the global nitrogen cycle and on weather and climate.

CURRENT RESEARCH:

Glaciers accumulate layers of snow and ice like trees accumulate layers of wood – one year at a time—creating records of temperature, productivity, fire, rainfall, air chemistry, and even plant cover—if you know how to look. But teasing out the information is a bit like trying to pick the sound of one violin out from an orchestra’s concerta.

The atmosphere is mostly nitrogen, but it’s the reactive form that is useful for plant growth and also implicated in smog formation and aquatic dead zones. Before industrialization, reactive nitrogen moved in modest – largely local – cycles. But fertilizer, global commodity trading, and ubiquitous fossil fuel use have more than doubled the amount of reactive nitrogen in circulation and redistributed it across the globe. Assistant Professor Meredith Hastings is using tracers of natural and human impacts on the nitrogen cycle through time using ice cores, and in the modern environment through studies of rain, snow, and particulate matter in the atmosphere.

Reactive nitrogen from North American fields, chimneys, and tailpipes is carried, on tiny particles and in water vapor, to Greenland, where it falls as snow and gets pressed into layers of ice.  The ratio of two kinds of nitrogen atoms in the ice—the lighter (and more common) 14N and the heavier (and rare) 15N—can tell Hastings whether a season’s nitrogen came from soil, coal, or vehicle emissions. Her first results (published in a 2009 paper in the journal Science) are promising, but she needs more information on the ratio of 15N to 14N in possible sources to use these tracers quantitatively.

Hastings’ group is making progress by developing a new method for analyzing source N and also studying the other components buried along with the nitrogen. For example, fine particles of black carbon suggest the source is burning, not soil microbes. Sulfur or thallium point to oil or coal, not wood.  Using historical records of industrial activity to understand variations in the recent ice, they are building a repertoire of correlations that will help them to interpret the deeper, older layers – before humans had a strong influence.  In time, they hope to be able to discern changes in wetland emissions during past rainy periods or increased forest and grassland fires during dry periods, offering further insight on the temperature and productivity profiles produced by other labs from ice and sediment records.  

 

July 2012

Assistant Professor Ralph milliken

Dr. Ralph Milliken's research focuses on the geologic evolution of planetary bodies, with an emphasis on the role of water, water-bearing minerals, and sedimentary processes.

His research group integrates laboratory techniques, theory, field work, and remote observations to understand how remote sensing techniques can be used to quantify mineral and chemical abundances on Earth and beyond.

Current projects include estimating the water content of the lunar surface by combining Moon Mineralogy Mapper reflectance data and laboratory experiments, deriving mineral abundances of lunar and meteorite samples using reflectance spectroscopy (a non-destructive method), and mapping the distribution of clay minerals on Mars. In addition, Dr. Milliken is a member of the science team for NASA's Mars Science Laboratory rover, Curiosity, which is schedule to begin its exploration of Mars in August. As a member of this team, he and his research group will help to map the geology of Gale Crater and participate in surface operations as the rover carries out its quest to search for habitable environments on Mars.