Full Length Research Paper

Estimation of different biologically effective irradiances at Visakhapatnam (17.7°N, 83.3°E) from standard action spectra

Narasipuram V. K. Prasad¹*, K. Niranjan² and N. Madhavi³

¹Department of BSH (Physics), GITAM Institute of Technology, Gitam University, Visakhapatnam, India.

²Department of Physics, Andhra University, Visakhapatnam, India.

³Department of Statistics, Andhra University, Visakhapatnam, India.

*Corresponding author. E-mail: krishna_narasipuram@yahoo. co.in.

Accepted 8 October, 2009.

   Abstract

Measurements of solar ultraviolet radiation in the biological band (280 - 320 nm) using a ground based UV-B Photometer at VISAKHAPATNAM have been used to estimate the biological effects of the incoming radiation on various species like human, animals, plants etc. with the help of standard action spectra. A comparison is made with TOMS ozone data to find the dependence on column ozone at a subtropical Indian station Visakhapatnam (17.7°N, 83.3°E). It is found that there is no significant change in the incoming biological effective radiation in the latitude (10 - 20° North) which corresponds to very less change in the columnar ozone content for this latitude. A bilinear regression model developed for this station was used to find the RAF (Radiation Amplification Factor) which indicates the change in the biological effect with respect to the corresponding change in ozone. The values of RAF for different biological effects were evaluated and are presented in this paper.

Key words: UV-B irradiance, TOMS ozone, RAF, regression model, solar zenith angle, action spectrum.