Radiation group

A model derived UV climatology

Ali Akbar Sabziparvar

This page gives climatological daily integrated surface UV data for various biological integrations of UV irradiances. These data were produced by Ali-Akbar Sabziparvar for his PhD thesis in the Department of Meteorology at the University of Reading

Please could readers email Piers Forster (piers@met.rdg.ac.uk) or Ali (swsabzi@sadaf.basu.ac.ir) before using any of these data. Feedback and questions are most welcome.

The main reference to this work is :

Sabziparvar, A. A., K. P. Shine and P. M. de F. Forster (1999) A model-derived global climatology of ultraviolet irradiation at the Earth's surface, Photochemistry and Photobiology, 69, 193-202.

See also:

Sabziparvar, Ali-Akbar (1997) "A Model derived surface climatology of surface daily ultraviolet irradiance including an estimate of trends due to changes in atmospheric composition", PhD thesis, University of Reading, UK. and

Sabziparvar, A. A., P. M. de F. Forster and K. P. Shine (1998) Changes in ultraviolet radiation due to stratospheric and tropospheric ozone changes since pre-industrial times, Journal of Geophysical Research, 103, 26107-26113.

UV model used

The model in a 4 stream discrete-ordinate radiative transfer code based on Stamnes et al. (1988), described in Forster (1995). -read the paper!

Method

Four point Gaussian integration was used to compute the daily integrated UV reaching the surface for the 15th of January, April, July and October. UV irradiances were calculated at 1 nm resolution between 280-400nm. These irradiances were then weighted with the appropriate function. For the UVA and UVB this was simply the total integral; for cataracts, keratitis and erythema a biological action spectra was used - These can be found in the PhD thesis or elsewhere.

A 3-D climatology of ozone, temperature, cloud and aerosol as well as surface albedo and surface pressure information was used in these calculation. This climatology was compiled by Rebecca Freckleton and Piers Forster.

The climatological ozone concentrations were based on a combination of ozonesonde and satellite Solar Backscattered UltraViolet instrument data; cloud and albedo data were derived from the International Satellite Cloud Climatology Project; and the temperature profiles were based on European Centre for Medium range Weather Forecasts analyses. The reader is referred to the PhD thesis for more information.

Results

Doses of UVB, ERYTHEMA, CATARACTS, KERATITIS, UVA

These come in the form of files for either clear sky, or cloudy sky with a background aerosol present. data is at 5 degree latitude and longitude resolution for the 15th of January, April, July and October. Each file is 10 columns wide of the form:

LONG (degrees), LAT (degrees), [UVB, ERYTHEMA, CATARACTS, KERATITIS, UVA] ( all in units of KJ/(sq. m day)), OZONE (Dobson Units), BLANK, DAY OF YEAR

Clear sky - no clouds or aerosol

January clear sky

April clear sky

July clear sky

October clear sky

Annual average clear sky - ignore last 2 columns

All sky - clouds and background continental aerosol of optical depth 0.1

January all sky

April all sky

July all sky

October all sky

Annual average all sky - ignore last 2 columns

Plots

Here are some postscript plots of the above files -very interesting!

UVB

January clear sky , April clear sky , July clear sky , October clear sky , Annual average clear sky

January all sky , April all sky , July all sky , October all sky , Annual average all sky

UVA

January clear sky , April clear sky , July clear sky , October clear sky

January all sky , April all sky , July all sky , October all sky

ERYTHEMA

January clear sky , April clear sky , July clear sky , October clear sky , Annual average clear sky

January all sky , April all sky , July all sky , October all sky , Annual average all sky

CATARACTS

January clear sky , April clear sky , July clear sky , October clear sky

January all sky , April all sky , July all sky , October all sky

KERATITIS

January clear sky , April clear sky , July clear sky , October clear sky

January all sky , April all sky , July all sky , October all sky

References

Look at:

Sabziparvar, A. A., K. P. Shine and P. M. de F. Forster (1999) A model-derived global climatology of ultraviolet irradiation at the Earth's surface, Photochemistry and Photobiology, 69, 193-202.

Sabziparvar, A. A., P. M. de F. Forster and K. P. Shine (1998) Changes in ultraviolet radiation due to stratospheric and tropospheric ozone changes since pre-industrial times, Journal of Geophysical Research, 103, 26107-26113.

Forster, P. M. de F. (1995) Modelling ultraviolet irradiances at the Earth's surface. Part I:the sensitivity of ultraviolet irradiances to atmospheric changes, J. Applied Meteorology, 34, 2412-2425 and references therein.

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