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DATA FROM A SOLAR ULTRAVIOLET MONITORING NETWORK
Citation:
Shreffler, J H. DATA FROM A SOLAR ULTRAVIOLET MONITORING NETWORK. Presented at Department of Statistics, Chapel Hill, NC, January 22, 2001.
Impact/Purpose:
To understand and characterize the factors, including optical transmission properties of aerosols, which affect the intensity of UV-B radiation measured at the earth's surface in order to improve our estimates of ecosystem and human exposures to UV-B radiation; to understand the relationship between UV radiation and total column ozone; to model UV-B exposures at different locations, conditions, and times in order to estimate UV-B exposures throughout the US. This objective is achieved by maintaining a strict quality assurance program for both the Brewer Spectrophotometers in the network and the UV data obtained from the Brewers.
Description:
The U.S. Environmental Protection Agency, in conjunction with the National Park Service, operates a network of 21 spectrophotometers, measuring spectrally-resolved, surface UV radiation of wavelengths 290-363 nanometers. Fourteen of the measurement sites are in National Parks, and the other seven are in urban areas.
A thin layer of ozone, principally in the stratosphere, absorbs much of the short wavelength UV (<320 nm) from the sun and protects life on the surface of the earth. Some very stable man-made chlorine compounds (e.g. refrigerants) have the potential to erode the ozone layer, and this deleterious effect may have been seen most dramatically over Antarctica (the "ozone hole").
This presentation will introduce fundamental concepts concerning ultraviolet radiation and the earth's ozone layer (with potential application to your next beach vacation). Data from the UV network will be presented, as well as measurements of column ozone from satellites. The calibration and operational characteristics of the spectrophotometer will be discussed. An intended objective is to show the wisdom of fully understanding instruments and measurements before launching into a statistical analysis. The possibility of detection of a trend in UV will be addressed.
This abstract covers an invited talk by the author to be given January 22, 2001 at the Department of Statistics, University of North Carolina, Chapel Hill. The material in the abstract may be used in the announcement material at UNC.