PALANCAR GUSTAVO GERARDO
Congresos y reuniones científicas
Título:
Evolution of erythemal solar radiation in Córdoba, Argentina: Effects of atmospheric factors
Autor/es:
MARIANA ACHAD; M. LAURA LÓPEZ; GUSTAVO G. PALANCAR; BEATRIZ M. TOSELLI
Lugar:
Córdoba
Reunión:
Congreso; 16th International Congress on Photobiology; 2014
Resumen:
rchange-newline">The most energetic solar radiation (the shortest wavelengths) reaching the Earth?s surface is in the UV
range. This interval is responsible of producing measurable effects on biological systems affecting
aquatic life and human health [1]. Different action spectrums are used to quantify these effects. For
example, McKinlay and Diffey (1987) [2] established the erythemal action spectrum, which
represents the spectral response of human skin to sunburn. The solar radiation weighted with this
spectrum is so called erythemal radiation (EUV, 280?400nm) and is affected by different factors such
as solar zenith angle (SZA), clouds, aerosol optical depth (AOD) and total ozone column (TOC).
Erythemal ultraviolet irradiance was recorded from 2000 to 2012 in Córdoba, Argentina. EUV values
under cloudless conditions are simulated by a radiative transfer (TUV4.1) model [3]. These model
estimations are tested against experimental measurements showing an excellent agreement (root mean
square error around 10%). EUV radiation and TOC temporal evolutions show a negative relationship.
The influence on EUV irradiance from clouds and SZA variability are the prevailing effects.
However, for a given SZA and clear-sky conditions, the total ozone and AOD are the main factors. In
order to quantify these effects, the radiation amplification factor (RAF) concept is introduced. The
overall mean radiation amplification factor due to total ozone (O3) (RAFO3) shows that 1% decrease in
total ozone results in an increase of 1.16±0.23% in the EUV irradiance. A similar analysis of the RAF
due to AOD (RAFAOD) shows that on average, a 1% decrease in AOD forces an increase of
0.082±0.012% in the EUV irradiance. Thus, overall sensitivity of UV to ozone was estimated to be
about thirteen times higher than to the aerosol.
Acknowledgments The author thanks CONICET and SECYT (UNC) for partial finantial support and
Mariana Achad thanks CONICET for a graduate fellowship.
[1] Diffey, B.L., 1991. Solar ultraviolet radiation effects on biological systems. Phys. Med. Biol. 36,
299?328.
[2] McKinlay, A.F., Diffey, B.L., 1987. A reference action spectrum for ultraviolet induced erythema
in human skin. Commission Internationale de l? Eclairage (CIE) 6, 17?22.
[3] Madronich, S., Flocke, S., 1997. Theoretical estimation of biologically effective UV radiation at
the Earth?s surface. In: Zerefos, C.S., et al. (Eds.), Solar Ultraviolet Radiation Modeling,
Measurements and Effects, NATO ASI Series. Springer, Berlin, pp. 23?48.
range. This interval is responsible of producing measurable effects on biological systems affecting
aquatic life and human health [1]. Different action spectrums are used to quantify these effects. For
example, McKinlay and Diffey (1987) [2] established the erythemal action spectrum, which
represents the spectral response of human skin to sunburn. The solar radiation weighted with this
spectrum is so called erythemal radiation (EUV, 280?400nm) and is affected by different factors such
as solar zenith angle (SZA), clouds, aerosol optical depth (AOD) and total ozone column (TOC).
Erythemal ultraviolet irradiance was recorded from 2000 to 2012 in Córdoba, Argentina. EUV values
under cloudless conditions are simulated by a radiative transfer (TUV4.1) model [3]. These model
estimations are tested against experimental measurements showing an excellent agreement (root mean
square error around 10%). EUV radiation and TOC temporal evolutions show a negative relationship.
The influence on EUV irradiance from clouds and SZA variability are the prevailing effects.
However, for a given SZA and clear-sky conditions, the total ozone and AOD are the main factors. In
order to quantify these effects, the radiation amplification factor (RAF) concept is introduced. The
overall mean radiation amplification factor due to total ozone (O3) (RAFO3) shows that 1% decrease in
total ozone results in an increase of 1.16±0.23% in the EUV irradiance. A similar analysis of the RAF
due to AOD (RAFAOD) shows that on average, a 1% decrease in AOD forces an increase of
0.082±0.012% in the EUV irradiance. Thus, overall sensitivity of UV to ozone was estimated to be
about thirteen times higher than to the aerosol.
Acknowledgments The author thanks CONICET and SECYT (UNC) for partial finantial support and
Mariana Achad thanks CONICET for a graduate fellowship.
[1] Diffey, B.L., 1991. Solar ultraviolet radiation effects on biological systems. Phys. Med. Biol. 36,
299?328.
[2] McKinlay, A.F., Diffey, B.L., 1987. A reference action spectrum for ultraviolet induced erythema
in human skin. Commission Internationale de l? Eclairage (CIE) 6, 17?22.
[3] Madronich, S., Flocke, S., 1997. Theoretical estimation of biologically effective UV radiation at
the Earth?s surface. In: Zerefos, C.S., et al. (Eds.), Solar Ultraviolet Radiation Modeling,
Measurements and Effects, NATO ASI Series. Springer, Berlin, pp. 23?48.
