Ultraviolet radiation measurements at Pune

Results of measurements of global solar ultraviolet radiation in the -wave length range 290-390 nm received from the sun and sky on a horizontal surface (OUVR) using an Eppley ultraviolet radiometer at Pune (18 N, 73 E) during 1972-73 are presented.   During the year on an average about 16 cal/cm2 are received daily as GUVR, the daily values ranging from 12-20 cal/cm2/day with lower values in winter, due to the lower solar- elevation angles at this time. The proportion of GUVR to global solar radiation (OR) is about 4 per cent with lower values, again in winter. This ratio also varies during the day, being a maximum at noon.   The mean hourly values of GUVR is about 3.9 cal/cm2/hour at noon in summer and about 2.0 cal/cm2/hour in winter. In general more GUVR is received in the forenoon than in the afternoon.   No marked influence of turbidity on the OUVR has been observed. However, the hourly values around noon show a decreasing trend with increasing turbidity.