Problems of determining snow albedo for the high arctic: Research note

Abstract

The measurement of radiation fluxes suffers from inaccuracies at low solar elevations and this poses a problem for determining the snow albedo at high latitudes. From the data of Resolute, NWT, three situations were observed: (1) an often‐reported situation when albedo decreases with increasing solar elevation, (2) an inverse situation when albedo increases with increasing solar elevation and (3) no obvious relationship. There were also cases when albedo exceeded 100%. The possible causes for such anomalous conditions or for erroneous albedos include instrument response deviating from the cosine law, instrument tilt, sensing of the sun by the inverted pyranometer and change in the spectral quality of incoming radiation with changing solar height. However, omission of the radiation values measured during the period of low solar elevation will not seriously affect the prediction of snowmelt. In this note, we have identified the anomalies and suggested possible causes; but further investigations are required to verify the causative mechanisms.