Estimation of the Solar Radiation Flux for an Arctic Surface

Abstract

<p> A previous study (Davies and Hay, 1978) described a method of calculating hourly and daily values of global solar radiation for cloudless and cloudy sky conditions. This scheme, requiring only upper air data from daily radiosonde ascents, and hourly surface weather observations, has been used successfully at a number of mid latitude sites (Davies et al., 1975; Suckling and Hay, 1976). In this investigation the extension of this method for use in an Arctic environment is presented. </p> <p> Solar radiation received at the earth's surface is the sum of direct and diffuse components. The flux in cloudless conditions is calculated as the residual after attenuation of solar irradiance by water vapour, ozone, Rayleigh scattering and aerosol. Cloudless sky values are then adjusted for cloud effects, using a cloud layer method similar to that used by Davies et al. in Southern Ontario, Canada. </p> </p> The computed values are compared with values measured at Resolute, N.W.T., Canada. Under cloudless sky conditions hourly and daily calculated values agree well with ·measurements. For days of cloud amount less than 4/10, model overestimates are observed. As cloud amounts increase varying degrees of model underestimation of measured values occur. This is linked with observer inability to adequately specify cloud amount, and the variation of cloud type transmission characteristics for Arctic areas. </p>