Impact of biomass burning aerosols on UV erythema-a case study from northeast region of India

Total spectral solar irradiance and biologically active solar ultraviolet radiation (UV_ery, 280-315nm) have been monitored during biomass burning period of moist deciduous forests in the Northeastern India. Aerosol optical depth values varied from 0.5 to 4.2 during different stages of burning. Total solar irradiance measurements suggested decrease in direct solar irradiance during burning with increase in diffused radiation. A statistical fit of AOD (500nm) through UV_ery shows negative gradient and for every 0.1 increase in aerosol optical depth during biomass burning period 0.01Wm^-2 reduction in the ground reaching UV_ery has been observed.