radiation.heatl {asbio} | R Documentation |
The function radiation.heatl calculates annual incident solar radiation (MJ cm^2 yr^-1) and heatload (a radiation index based on the idea that highest amounts of radiation occur on southwest facing slopes in the northern hemisphere).
radiation.heatl(slope, aspect, lat)
slope |
slope (measured in degrees) |
aspect |
aspect (measured in degrees) |
lat |
latitude (measured in degrees) |
The function requires three types of data: slope
(measured in degrees), aspect
(measured in degrees), and northern latitude = lat
(measured in degree). The function is based on equations from a paper written by McCune and Keon (2002). Note that this function ignores climatic factors including cloudiness, and is therefore is probably best for relative comparisons of radiation and heatload within a region and not for absolute measurements.
radiation |
Annual incident radiation in (MJ cm^2 yr^-1) |
heatload |
A unitless measure of heatload, maximized on SW aspects. |
Ken Aho
McCune, B., and D. Keon (2002) Equations for potential annual direct radiation and heat load. Journal of Vegetation Science, 13: 603-606.
slope<-20 asp<-25 lat<-46 radiation.heatl(slope,asp,lat)