Abstract: Solar Ultraviolet (UV) radiation reaching the Earth’s surface has significant impacts on the environment including agriculture crops, rangeland grasses, and forests. Reductions in UV-absorbing stratospheric ozone resulting from climate change and the anthropogenic emission of ozone depleting substances raised concerns regarding future levels of surface UV radiation. Responding to this potential threat, the U.S. Department of Agriculture established the UV-B Monitoring and Research Program (UVMRP) in 1992. There are three primary goals in UVMRP: (1) to monitor surface-level solar UV and visible radiation across the U.S.; (2) to investigate the effects of UV and other environmental stressors on economically important crops through experiments; and (3) to provide science-informed decision support toward sustainable U.S. agriculture by developing the coupled Climate-Agroecosystem-UV Interactions and Economic impacts (CAIE) modelling framework. The UVMRP currently consists of 37 climatological monitoring sites, each is equipped with four primary irradiance instruments including: (1) UV MultiFilter Rotating Shadowband Radiometer (UV-MFRSR); (2) visible MFRSR; (3) UVB-1 broadband meter; (4) Photosynthetically Active Radiation (PAR) sensor. The irradiance measurements and the derived products are distributed through the UVMRP website. For effects research, the UVMRP and its collaborators in Mississippi State University conduct experiments using computer-controlled environmental chambers. In addition, UVMRP is collaborating with the University of Maryland to build/improve the component models of the CAIE framework and to couple these components. The core components of CAIE include the climate model (the regional Climate-Weather Research and Forecasting model, CWRF), the crop models (GOSSYM and DSSAT), the biogeochemical model (DayCent), and the economic models.
