An ultraviolet radiation monitoring and research program for agriculture

The United States Department of Agriculture (USDA) Ultraviolet-B Monitoring and Research Program (UVMRP) was initiated in 1992 through a grant to Colorado State University (Fort Collins, CO, USA), authorized by Congress under the USDA Cooperative State Research Education and Extension Service (CSREES) Special Research Grant authority, to provide the agricultural science research community with the information necessary to determine if changing levels of UV-B radiation would threaten food and fiber production in the United States. The UVMRP consists of three major components: (1) monitoring solar radiation with an emphasis on UV-B radiation; (2) research to determine the effects of UV radiation on specific plants and crops; and (3) crop growth and production assessment modeling to assess the impact of climate change scenarios on crop production. The monitoring network, consisting of UV and visible solar radiation measurement instrumentation installed at 37 climatological sites, is described in this chapter, along with the basic algorithms used to process the data and the calibration methods designed to provide accurate long term data records. Procedures developed to provide aerosol optical depth, columnar ozone, and enhanced products, such as integrated irradiances weighted with biological spectral weighting functions and summed over selected time periods, are also described. An updated, flexible web page interface that allows users to access various data products is documented. The UVMRP's role in UV-B agricultural effects studies is summarized, including contributions by scientists at several collaborating universities. The UVMRP's component that models agricultural sustainability by coupling a state of the science climate forecasting model to crop growth models in order to obtain the impact of climate change scenarios on crop yield is introduced. Future directions of UVMRP are also presented.