The Radiation Balance of Alpine Tundra, Plateau Mountain, Alberta, Canada

Publisher Website
Google Scholar
Abstract
Measurements of radiation balance components made at an alpine tundra site in the Rocky Mountains of southwestern Alberta, Canada, during the summer of 1985 are reported. Measurements of global solar radiation and reflected solar radiation permitted the evaluation of half-hour and daily net solar radiation, albedo, and atmospheric transmissivity. These were coupled with net radiation and surface temperature measurements to evaluate half-hour and daily incoming outgoing, and net longwave radiation. Below-average cloud amounts resulted in high daily atmospheric transmissivities. Maximum daily transmissivity reached 80% on near cloudless days. Throughout the study period, daily albedo was nearly constant at 17%. When compared to net solar radiation, the variability in the daily trend of net longwave radiation was conservative. The magnitude of the radiation balance was principally controlled by atmospheric transmissivity. The amount and duration of cloud cover were the chief factors influencing daily atmospheric transmissivity. During cloudless and cloudy-bright conditions, transmissivity was high. During periods of overcast, the decreased transmissivity reduced all solar components. Surface control through albedo was minimal, except for the brief period following a snowfall. No seasonal impact on albedo as a result of surface drying was found. Atmospheric haze resulting from distant forest fires reduced all solar radiation balance components. As a consequence of the dominance of global solar radiation balance, both half-hour and daily radiation values were well correlated with global solar radiation.

This publication has 2 references indexed in Scilit: