Environmental, Geographic, and Geological Sciences

becker-research\

Stefan Becker

Research

As a Physical Geographer, I have always been fascinated by our natural environment and the changes that humans have caused in it. I have been particularly interested in atmospheric processes and environmental change in various regions of our world. Pursuing these interests has allowed me to get to know fascinating cultures and environments. I have studied changes in rainfall patterns in Tibet and in the Yangzte River basin in China and their impact on flood events. I am collaborating with national and international colleagues on developing future scenarios and improving the forecast of severe flood events in the region. My research interests have also led to me to other regions: I have studied the distribution of air pollution from coal-fired power stations and their impact on humans in South Africa, heat-stress in Israel, regional impacts of climate change in Wisconsin, and wind energy potential in Germany. In recent years, I have contributed to the understanding and modeling of hurricane track and intensity changes in the Atlantic. I will pursue these and other (including local) research goals at Lehman College and I am looking forward to working together with students, who are interested in these projects.

Current Research Projects

Neural Network Based Analysis and Forecast of Hurricane Tracks in the Western Atlantic

Outline:

The forecast of a hurricane track is an important tool in preparing a region for an approaching tropical thunderstorm and thereby mitigating the potentially disastrous impacts. Numerous track forecast models have been developed and applied to achieve this goal. Hurricanes in the Western Pacific and Caribbean Region are analyzed in the United States chiefly by the National Hurricane Center (NHC) in Miami, Florida. With ever-increasing computational power for high-resolution numerical simulations, one could expect analogous improvement in accuracy for tropical cyclone track and intensity predictions. However, recent events, such as the significant uncertainty and inaccuracy of Hurricane Katrina and Ophelia’s track forecasts, as well as events during the 2004 hurricane season, have shown that hurricane track and intensity predictions still present great challenges. The purpose of this research project is to develop an alternative, neural network based method for hurricane track forecasting. A neural network is an advanced statistical procedure or a computer network designed to function in a similar way to natural neural structures such as a human brain. Numerous independent variables such as air pressure constellations and winds in the lower and upper atmosphere of the near and far field of a hurricane will be related to hurricane tracks of the past 50 years utilizing an advanced nonlinear neural network system. The expected outcome will be a combination of variables that contributes to the explanation of past hurricane tracks, and an additional short term forecast model based on the capability of a learning system that relates historical hurricane tracks to atmospheric dynamics.

Collaborators:

  • Prof. Dr. Marcus Buker, University of Western Illinois, Macomb, USA
  • Prof. Dr. Robert Rohli, Louisiana State University, Baton Rouge, USA
  • Prof. Dr. Corene J. Matyas, University of Florida, Gainesville, USA

Photo: Hurricane Katrina 2005 and upper air vorticity patterns

Precipitation Trends and Cycles in the Yangtze River Catchment, P.R. China

Daily precipitation data of 150 measuring stations in the Yangtze River catchment area are analyzed to detect trends and cycles in the frequency of occurrence of extreme precipitation events. The research project builds upon previous works on precipitation trends of monthly and annual precipitation totals (see publication list). In addition to incorporating daily data into the study we are currently focusing on explaining the observed trends and cycles based on teleconnections to pressure wind and SST patterns.

Collaborators:

  • Prof. Dr. Mamadou Coulibaly, Department of Geography and Urban Planning, University of Wisconsin Oshkosh, USA
  • Prof. Dr. Klaus Fraedrich, Meteorologisches Institut Universität Hamburg, Germany
  • Prof. Dr. Marco Gemmer, Chinese Meterological Administration, Beijing, China
  • Prof. Dr. Lorenz King, Institut für Geographie, Justus-Liebig Universität Giessen, Germany
  • Prof. Dr. Zhang Qiang and
  • Prof. Dr. Jiang Tong, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, People’s Republic of China
  • Prof. Dr. Wu Yijin, Huazhong Normal University, Wuhan, People’s Republic of China
Photos: China

At the Three Gorges Project

On the Great Wall

In Tibet

At the Mount Everest

Historical Changes in Lake Ice-Out Dates in Wisconsin as Indicators of Climate Change

100 years of ice-out data of the Lake Winnebago and other lakes in Wisconsin are analyzed as indicators of climate change. The time series show significant negative trends which are overlain by distinct long-term cycles and annual fluctuations. One aim of the research project is to explain the variability of the ice-out dates as a function of air temperature, precipitation and synoptic weather patterns. The function approximation will be achieved by an artificial learning system (Neural Network) and will ultimately enable the hind- and forecast of ice-out dates. A fine-tuning of the model will be based on the implementation of weekly measurements of the ice thickness from the Winter 2007/2008 season onward. A second aim of the project is to explain long-term trends and cycles of the ice-out dates as a function of regional climate change and atmospheric oscillation signals.

Collaborators:

  • Prof. Dr. Colin Long, Department of Geography and Urban Planning, University of Wisconsin Oshkosh, USA
  • Prof. Dr. Marcus Buker, University of Western Illinois, Macomb, USA
  • Prof. Dr. Mamadou Coulibaly, Department of Geography and Urban Planning, University of Wisconsin Oshkosh, USA
  • Prof. Dr. Robert Pillsbury, Department of Biology, University of Wisconsin Oshkosh, USA

Lake Winnebago

Atmospheric Boundary Layer Characteristics and Sulfur Dioxide Pollution Levels over the South African Mpumalanga Highveld

Research on air pollution with emphasis on sulfur dioxide on the South African Mpumalanga Highveld is highly relevant for this region because of the agglomeration of power stations and industry. The agglomeration is due to the industrial development of South Africa and the extensive coalfields, which are located in this region. Enormous amounts of sulfur dioxide are released into the atmosphere particularly by power generation and could possibly be detrimental e.g. to human health if they reached the ground level in highly populated areas. The research focuses on modeling the atmospheric parameters, which are relevant to the dispersion of the pollution, as well as on modeling near ground air pollution levels including their spatial distribution.

Photos: South Africa (2008)

Regional Impacts of Climate Change on Human Heat Stress in Israel

Collaborators:

  • Dr. Oded Potchter, Beit Berl College, Israel
  • Yaron Yaakov, Tel Aviv University, Israel

Photos: Israel 2010

 

Concluded Research Projects

  • Title: Heat Stress in Israel
    Time: 1992 – 1993
    Funded by: Minerva Committee (Germany/Israel)
    P.I.: Stefan Becker
    Sum: approx. 27,000 US$
  • Title: Evaluation of the Bioclimate of South African Cities and Resorts
    Time: 1996 – 1997
    Funded by: DAAD (Deutscher Akademischer Auslandsdienst)
    P.I.: Stefan Becker
    Sum: approx. 25,000 US$
  • Title: Geo-ecological Evaluation of various Holiday Resorts
    Time: 1994 – 1996
    Funded by: IFF (Institut für Freizeitanalysen) Bochum, Germany Verlag Milchstrasse, Hamburg, Germany
    P.I.: Stefan Becker
    Sum: approx. 20,000 US$
  • Title: Human Perception of Climate in Extremely Hot and Arid Environments
    Time: July 2001
    Funded by: Research Funds of the University of Gießen, Germany
    P.I.: Stefan Becker and Oded Potchter
    Sum: approx. 1,000 US$
  • Title: Climate Change and it’s Impacts on Flood Events in the Yangtze Catchment
    Time: 2001 – 2003
    Funded by: German Federal Ministry of Education and Research, International Bureau (BMBF-IB) and Chinese Academy of Sciences (CAS). The research program of Stefan Becker is funded as a part of the WTZ-Projekt CHN 01/105 with PIs Prof. Dr. L. King and Prof. Dr. T. Jiang
    Sum: approx. 15,000 US$
  • Title: Contribution of Teleconnections for the Explanation of Rainfall Variability in the Yangtze River Catchment
    Time: 2004 – 2006
    Funded by: German Research Association
    P.I.: Stefan Becker
    Sum: approx. 150,000 US$
  • Title: Neural Network Based Analysis and Forecast of Hurricane Tracks in the Western Atlantic
    Time: 2006
    Funded by: Faculty development program of the University of Wisconsin Oshkosh
    P.I.: Stefan Becker
    Sum: approx. 3,500 US$
  • Title: Neural Network Based Analysis and Forecast of Hurricane Tracks in the Western Atlantic
    Time: 2007
    Funded by: Faculty development program of the University of Wisconsin Oshkosh
    P.I.: Stefan Becker
    Sum: approx. 7,500 US$

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Last modified: Oct 13, 2011

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