RADIATION CLIMATOLOGY: SOME ILLUSTRATIVE CASE STUDIES

A wide range of natural systems are responsive to temporal changes (e.g., diurnal, seasonal) in the flow of radiant heat energy generated by the Sun. The receipt of this energy at the Earth's surface is not simply a function of time, but is also strongly influenced by cloud cover and the orientation of the receiving surface relative to the Sun. While the ultimate objective in radiation climatology is to document and interpret the average radiant energy exchanges, much can be learned from an examination of appropriate instantaneous data (i.e., case studies). This paper provides a number of appropriate examples culled from 7 years of hourly observations of solar radiation incident on horizontal and inclined surfaces, from 4.5 years of data from a 12-station mesoscale network, and from published archives.

The examples show diurnal variations in the total, direct, and reflected short-wave and incoming and outgoing long-wave radiation for clear and overcast skies in both summer and winter; for the four seasons, typical clear sky diurnal variations in the solar energy incident on horizontal and inclined surfaces; and at both the meso and macro scales, the hour-by-hour and day-by-day changes in the attenuation of solar radiation associated with the passage of a frontal synoptic weather system.