Research Title: Polar Ozone Depletion and Ultraviolet Radiation Effects
Funding Level (millions of dollars):
Committee on Environment and Natural Resources (CENR) Component:
(a) Subcommittee: Global Change Research Subcommittee (100%) NSTC Committee on Fundamental Science
(b) Environmental Issue: Chemically Induced Changes (100%)
(c) Research Activity: Impacts and Adaptations: Ecosystems
Office of Polar Programs
National Science Foundation
4201 Wilson Boulevard
Arlington, VA 22230
Point of Contact:
Polly A. Penhale
To determine the mechanisms and causes of the "Antarctic Ozone Hole" and the differences between the Arctic and the Antarctic, to measure and predict the increased levels of ultraviolet (UV) radiation reaching the Earth's surface due to stratospheric ozone depletion in polar regions, and to understand the biological consequences of those increases.
The Polar Ozone Depletion and Ultraviolet Radiation Effects activity is a focused atmospheric and biology program designed to better understand how stratospheric ozone is depleted and its consequences (via increased UV radiation) on ecosystem structure and function, and how to better predict the levels of UV radiation penetrating to the Earth's surface. It is very important to understand fully the causes of stratosphere ozone depletion, because stratospheric ozone filters out biologically damaging solar ultraviolet (UV) radiation, and because the polar chemical and dynamic processes that cause it are harbingers of future similar ozone depletion at more temperate latitudes. It is known that the chemical processes which destroy the ozone are driven mainly by chlorine from chlorofluorocarbons, but there is still much to be learned. This requires laboratory studies of detailed chemical processes, field observation of concentrations and distribution of chemical species, and improvements in modeling of stratospheric chemistry and dynamics. The stratospheric "ozone hole" has allowed increased penetration of UV radiation to the earth's surface in polar regions where it has been historically low. Research is focused on understanding the effects of enhanced UV radiation on marine, freshwater and terrestrial biota and on ecosystem structure and function. Efforts are directed towards measurements and modeling efforts to predict UV penetration through the atmosphere to the Earth's surface and into aquatic systems. The NSF supported and operated polar UV monitoring network that is located at several permanent stations in Arctic, Antarctic and sub- Antarctic regions provides high resolution surface data which facilitates research in several disciplines. This program has established a (polar) UV data base that for the first time has calibrated long-term stability. Data from the last few years is readily available in CD-format. This has been used to demonstrate (i) the increase in biologically active UV dosages in spring (20%) due to a reduction of ozone (-8%), (ii) a reduction in phytoplankton photosynthesis of 6-12% in the "ozone hole", and (iii) marine organism defense mechanisms. However, CFC residence times are ten years or more, and therefore, this program must continue for at least a decade to reduce the uncertainty and map the future reductions and recoveries.
The study of polar ozone depletion is of interagency interest with NOAA and NASA playing a major role, along with NSF. The study of UV radiation and its effects in polar regions has been concentrated within NSF, with increasing interest in other agencies. The general world-wide interest in UV radiation-related research has resulted in plans to establish a US Interagency In-situ UV Monitoring Network, a national UV instrument calibration facility and national data network. This involves USDA, DOE, EPA, DOI, NASA, NOAA, NIST and NSF. International cooperation includes joint efforts in both ozone depletion and UV radiation research.
1994: Provided logistical support related to NASA-sponsored aircraft and satellite missions, and supported a high-resolution polar UV radiation monitoring network in the southern hemisphere. 1995-1998: Conduct research projects on Antarctic stratospheric trace gases and aerosols and their relationship to the ozone hole and on the effects of UV radiation on organisms and ecosystems; and develop and validate models that more accurately depict the penetration of UV radiation through the atmosphere; 1996: Establish a high-resolution national UV radiation monitoring network.
Field, laboratory, and theoretical/modeling efforts will aid understanding of the effects of human activity on global ecosystems. This research also continues to support policy decisions aimed at the control of the use of halocarbons. Recent public debate has emphasized the rapid phase-cut of CFC's and some have questioned the scope of the problem. This program is needed to assess these issues and to monitor the impact of the Montreal Protocol.