MONITORING UV-B AT THE EARTHS SURFACE

High skin cancer rates, stratospheric ozone depletion and increased pu blic interest and concern have resulted in a strong demand for solar u ltraviolet radiation measurements and information, The Australian Radi ation Laboratory (ARL) has been involved since the mid-1980s in the me asurement of solar ultraviolet radiation (UVR) using spectroradiometer s and a network of broadband detectors at 18 sites in Australia and An tarctica, Measurement locations range from tropical (Darwin, 12.4 degr ees S) to polar (Mawson, 67.6 degrees S) and as a result there are man y difficulties associated with maintenance and calibration of the netw ork detectors and transfer of data to ensure an accurate and reliable data collection, Calibration procedures for the various detectors invo lve the comparison with simultaneous spectral measurements using a por table spectroradiometer incorporating a double monochromator, calibrat ed against traceable standard lamps, Some laboratory measurements of c osine response and responsivity are also made, Detector-datalogger sys tems are intercompared at the Yallambie site for a number of months be fore installation at another location, As an additional check on the c alibrations, computer models of solar UVR at the earth's surface for d ays with clear sky and known ozone are compared with the UV radiometer measurements.