Measuring the vertical albedo profile of a subarctic boreal forest canopy
The validation of airborne and satellite-derived albedo measurements suffers from the fact that the surface albedo of forest is difficult to measure in-situ over large areas. The goal of this study is to examine whether or not the estimation of the surface albedo of a forest stand from ground level measurements is possible. In addition, knowledge about the vertical behavior of albedo, and therefore transmitted solar radiation, is important in the modeling of interactions of sunlight with the forest canopy. Such modeling is useful for forest growth estimations among other things. To achieve these goals, an albedometer set-up capable of vertical albedo profiling has been used to obtain data from a boreal forest stand in Northern Finland during periods in summer 2006 and winter 2007. The results show a strong relationship between the data and fitted power-law regression curves. Power-law regression fits best likely because of the radiation transmission characteristics of boreal forest.
Received 28 March 2008 Accepted 27 August 2008 Published 31 December 2008