Service of monthly mean Linke turbidity and atmosphere parameters

This resource serves monthly climatological values of Linke turbidity for air mass 2, water vapour, Angstroem beta and stratosph. ozone on a global scale. It calculates the monthly mean values for any geographical location, any month and any elevation.

The altitude of the geographical site of simulation can be either extracted from the orography resource (if set to 0) or forced by the user by inputting a value greater than or equal to 1. Unit is meter. The orography resource has a grid cell of 5' of arc angle and uses the data base TerrainBase (TerrainBase, Worldwide Digital Terrain Data. Documentation Manual, CD-ROM Release 1.0, April 1995. NOAA, National Geophysical Data Center, Boulder, Colorado, USA).

The Linke turbidity presented here is based on several global information from satellites like global clear sky radiation (SRB), precipitable water vapour (NVAP), aerosol optical depth (pathfinder) and ground information about turbidity from radiation or aerosol measurements (AERONET). Turbidity has been calculated with beam or global radation measurements at the ground with help of the ESRA clear sky radiation model. Satellite and ground information have been fitted together. Accuracy: rmse = 0.7 TL units. The way of constructing the database is explained on the Web site HelioClim.

The other atmosphere parameters: Water vapour (WV) or total precipital water is taken from NVAP and corresponds to mean values of 1988-97 (maps unit=[cm]: January, February, March, April, May, June, July, August, September, October, November, December). Ozone (O3) is taken from GOME and corresponds to mean values of 1996-2000 (maps: January, February, March, April, May, June, July, August, September, October, November, December). The standard deviation of Ozone during the 5 years is shown for 4 months in the following maps: January, April, July, October. Angstroem beta (BE) is calculated with TL and water vapour.

The most important sources and references of data are:

Satellite:

Pathfinder: http://las.saa.noaa.gov/las-bin/climate_server/dset=AVHRR+PATHFINDER

Water vapour: http://www.cira.colostate.edu/climate/NVAP/bulletin.htm

Ground information:

Holben B.N., D.Tanré, A.Smirnov, T.F.Eck, I.Slutsker, N. Abuhassan, W.W. Newcomb, J.S. Schafer, B Chatenet, F. Lavenu, Y.J.Kaufman, J. Vande Castle, A.Setzer, B.Markham, D. Clark, R. Frouin, R. Halthore, A.Karneli, N. T. O'Neill, C. Pietras, R.T. Pinker, K. Voss, G. Zibordi : An emerging ground-based aerosol climatology. Aerosol optical depth from AERONET, submitted to J. Geophys. Res, 2000.

Rigollier, C., O. Bauer and L. Wald (2000): On the clear sky model of the ESRA with respect to the heliosat method. Solar Energy, Vol.68, No.1, pp.33-48, 2000.

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