Integrated insolation over the part during which daily-mean insolation exceeds a threshold, expressed in W/m2
thrins(lat = 65 * pi/180, orbit, threshold = 400, ...)Time-integrated insolation in kJ/m2 . The quantity is calculated by brute-force integration with a 1-degree time-step in true solar longitude and this can be quite slow if long series are to be calculated.
latitude
Output from a solution, such as ber78, ber90 or
la04
threshold insolation ,in W/m2
other arguments to be passed to Insol
Michel Crucifix, U. catholique de Louvain, Belgium.
Algorithm is by M. Crucifix, but the idea of thresholded insolation is due to Huybers and Tziperman (2008), reference below.
P. Huybers and E. Tziperman (2008), Integrated summer insolation forcing and 40,000-year glacial cycles: The perspective from an ice-sheet/energy-balance model, Paleoceanography, 23.