Addition of mean solar zenith angle
Code added to calculate the mean solar zenith angle and lit fraction over a time period, for example a 3-hourly climate model output. Support exists for all calendars available in cftime
. This is useful for solar energy and UTCI applications as it enables us to estimate what the time-averaged direct normal irradiance from a climate model might be given the total horizontal (rsds) and diffuse horizontal (rsdsdiff).
One other change: twolayermodel
has default year length set to 365.24219 days, with option to specify it.