Duration of Vitamin D Synthesis in Human Skin

Version 1.0, Copyright © 2005 NILU, Ola Engelsen
Norwegian Institute for Air Research

Press here for more information on VitD and other model versions


Solar Geometry for Irradiance Calculations

Month Day

Latitude (degs N) Longitude (degs E)

When checked, use degrees for Solar Zenith Angle directly and ignore Date, Time, and Location


Cloudless sky: Visibility of km, Range [5-350] km. Ångström β of , Range [0.0-0.4] (AOD = βλµm-1.3).

Scattered clouds: Cloud fraction of %, Range [0-100]. Cloud liquid water column of g m-2, Range [0-5000].

Broken clouds (radiation enhancement): Cloud liquid water column of g m-2, Range [0-5000].

Overcast sky: Cloud liquid water path (LWP) of g m-2, Range [0-5000]. (Thin clouds: LWP < 50 g m-2; Thick clouds: LWP > 500 g m-2)


Total ozone column: Dobson Units (DU), Range [100-600]
Press here for total ozone column measurements from the satellite instruments (OMI).


Surface altitude km. Range [0.0-6.0] km

Surface albedo of Range [0.0-1.0].

Surface type:







This work has been funded by the European Commission (EC) and the Norwegian Research Council ( NFR) through the projects UV Radiation in the Arctic: Past, Present and Future (UVRAPPF) and European Database for UV Climatology and Evaluation (EDUCE).

Contact: nilu@nilu.no (Arve Kylling or Tove Svendby)
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