Human-induced Climate Variations on Urban Areas: From Observations to Modeling



Dr. J. Marshall Shepherd
Science Communications Manager, Code Y
NASA Headquarters
Washington, D.C. 20546
V: (202) 358-1702
Marshall.Shepherd@nasa.gov

Dr. Menglin Jin
Department of Meteorology
University of Maryland, College Park, 20742
mjin@atmos.umd.edu
Phone: (301)-405-8833
fax: (301)-314-9482
Phone: (301)-405-8833

The goal of this section is to bring together the scientists from interdisciplinary background to discuss the data, scientific approaches and recent results on urbanization monitoring and simulation. This will identify our current stand and the future direction on this topic.

Urbanization is one of the extreme case of land use change. Most of population of the world has moved to the urban areas. By 1995, more than 70% of population of North America and Europe live in cities. Although currently only 1.2% of the land is urban areas, the spatial coverage and density of cities are expected to rapidly increase in the near future. Urban construction changes surface roughness, albedo, heat capacity and vegetation coverage. Traffic and industry increase atmosphere aerosol and thus modify urban rainfall through aerosol-cloud interactions and dynamic mechanism. However, our understanding of urbanization effect is incomplete becasue urban effect is affected by many factors including land cover, city's microscale features, population density, and people's living style. Better understanding of how the atmosphere-ocean-land-biosphere components interact as a coupled system and the influence of human activities on this system is critical.

An interdisciplinary effort combining remote sensing, boundary layer microphysics, GCM modeling, and human dimension study is desired to address questions such as:
  • (1) How does urbanization modify climate system and how can nature tolerate and respond to such disturbance?
  • (2) What would be the ranges and extremes of urban effect?
  • (3) How could we quantitatively generalize these modifications in GCM?
  • (4) How does urban area change local rainfall intensity and frequency?
  • (5) What are the changes on aerosol and clouds due to human activities?