The purpose of this project is to ensure continuation of UV observations at Barrow and Summit over the period 1-August 2012 ? 31-July 2015. These data include spectra of solar spectral irradiance between 280 and 600 nm, biologically effective dose-rates, total ozone, surface albedo, cloud optical depth, actinic flux, and photolysis rates for common reactions such as the photolysis of O3 and NO2. All data are made available via ACADIS, WOUDC, and NDACC. At Barrow, several key parameters affecting UV radiation such as snow cover and sea ice extent are changing rapidly. Extension of the climate data record (CDR) will provide a unique opportunity to study the effect of a changing environment on UV radiation. Measurements at Summit are ideally suited to probe the free troposphere and study the effects of long-range transport of pollutants and aerosols on UV radiation. The key intellectual merit of the proposed project centers on acquiring data that can be used to advance knowledge (1) of the present and future solar radiation climate of the Arctic and (2) of the factors that drive changes in the UV radiation. For example, by combining UV data with other measurements and modeling, parameterizations can be developed to predict future UV intensities and improve climate models (e.g., CCMs). Analysis of the long UV data record from Barrow will also help answering the ?SEARCH Question? whether the Arctic is moving to a new state. UV data are of importance for other AON projects and augment their intellectual merit. The broader impacts of this activity are to provide data to researchers in various disciplines, including satellite ground truthing, and to educators for use in science courses and curricula. The PIs intend to continue contributing to the NOAA Arctic Report Card and integrating the data into non-major courses at the university.
