Surface Levels of Ultraviolet-B Radiation Under Variable Conditions of Tropospheric Air Quality And Cloudiness

EPA Grant Number: R825248
Title: Surface Levels of Ultraviolet-B Radiation Under Variable Conditions of Tropospheric Air Quality And Cloudiness
Investigators: Saxena, Vinod K. , Frederick, John
Institution: North Carolina State University , University of Chicago
Current Institution: North Carolina State University , University of Chicago
EPA Project Officer: Shapiro, Paul
Project Period: October 1, 1996 through September 30, 1999
Project Amount: $374,702
RFA: Exploratory Research - Air Chemistry & Physics (1996) RFA Text |  Recipients Lists
Research Category: Air Quality and Air Toxics , Air , Engineering and Environmental Chemistry

Description:

Using strategic locations at a mountain-top which frequently stays in the free troposphere, and in the valley which is invaded by air masses with contrasting physic-chemical characteristics, it is proposed to: (1) measure UV-B irradiance at the mountain-top and in the valley when the contents in the boundary layer are influenced by (a) clean maritime air mass, (b) continental air mass, and (c) polluted urban-industrial air mass; (2) characterize the physic-chemical properties of the aerosol transported to the experimental site by the three different and contrasting air masses; (3) digitize the cloud cover using a high resolution video camera; (4) analyze the field measurements for a comprehensive evaluation of the impact of aerosols, cloud cover, and solar zenith angle on the tropospheric UV-B transmission; (5) determine the degree to which the measured irradiances deviate from expectations for a clear unpolluted atmosphere; and (6) interpret the deviations in object (5) in terms of cause and effect. The mountain-top location is a site in the Mount Mitchell State Park home of the highest peak (6,684 ft or 2,038 m MSL) in eastern U.S. and a United Nations Biosphere Reserve, and the valley location is at an elevation of 900 m MSL in Black Mountain, close to the Asheville watershed. During the proposed three year study, our investigations will focus on answering the following question: How successfully can we detect a downward trend in stratospheric ozone by monitoring the surface UV-B irradiance from a network of ground-based stations in the U.S.? Our database will help decipher the trend by interpreting the UV-B measurements under variable conditions of tropospheric air quality and cloud cover.

Publications and Presentations:

Publications have been submitted on this project: View all 32 publications for this project

Journal Articles:

Journal Articles have been submitted on this project: View all 13 journal articles for this project

Supplemental Keywords:

troposphere, air quality, ozone, monitoring, aerosol, stratospheric ozone, measurement., RFA, Scientific Discipline, Air, Environmental Chemistry, climate change, tropospheric ozone, Atmospheric Sciences, urban air, environmental monitoring, ambient ozone data, boundry layer processes, climate variations, ozone, weather factors, aerosol/ cloud interactions, air pollution models, air quality data, aerosol sampling, atmospheric monitoring, ambient aerosol particles, UV-B radiation, climate variability

Relevant Websites:

http://www4.ncsu.edu/unity/users/s/saxena/public/cloud.html Exit EPA icon

Progress and Final Reports:

  • 1997 Progress Report
  • 1998 Progress Report
  • Final Report