UV index and UV dose: data product description
data version 2.x

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UV radiation
monitoring:

UV index
UV dose

Main data product description page
 

Introduction

The TEMIS UV index and UV dose data are computed from the assimilated global ozone field at local solar noon, i.e. at the moment the Sun is highest in the sky, which in case of the UV dose is combined with the daily variation of the position of the Sun above the horizon.

There are two UV data records, based on different ozone data:

Clear-sky UV index and clear-sky UV dose data is provided for both ozone records and covers the whole world. Cloud-modified UV dose data is provided only for the operational ozone record and covers the part of the world observed by the geostationary Meteosat Second Generation (MSG) satellites.

 

Details of the computation of the UV index and UV dose

 
===> Publications and references for the TEMIS UV data services and datasets.

 

Data files and plots

The UV index and UV dose data are given at a latitude-longitude grid of 0.25 by 0.25 degrees covering the whole world in HDF-4 files. UV index files contain the clear-sky local noon UV index data, whereas UV dose files contain both the clear-sky and cloud-modified UV dose data. All files also contain the local solar noon ozone data at the UV grid.

The structure of these files is described on a separate page.

The website shows plots of the UV index and UV dose data in four domains: World, Europe, Netherlands and Dutch Caribbean.

 

Data version 2.2 improvements w.r.t. version 2.1

This version contains an improvement in the cloud modification factor for the cloud-modified UV dose, due to an update of the input MSG CPP cloud data -- see here for some notes. The previous data has not been reprocessed.

At the same time the regional map of the "Dutch Caribbean" is extented to "Dutch Caribbean & Suriname"; the maps of previous data have not been reprocessed.

For the operational processing TEMIS operational record v2.2 is effective as of 22 March 2021, while for the Multi-Sensor Re-analysis (MSR-2) record v2.2 is effective as of 1 January 2020.

 

Data version 2.1 improvements w.r.t. version 2.0

This version contains an improvement of surface albedo climatology used in the UV index and UV dose data. The impact of this on the UV index and UV dose values are small -- see the upgrade notes on the surface albedo correction page -- and therefore the previous data has not been reprocessed.

For the operational processing TEMIS operational record v2.1 is effective as of 16 December 2020, while for the Multi-Sensor Re-analysis (MSR-2) record v2.1 is effective as of 1 January 2020.

 

Data version 2.0 improvements w.r.t. older versions

A first evaluation of the data has shown that the differences in the cloud-free UV index and UV dose data lie on the whole within the error on the v2.0 data, except for a few specific events.

The major improvements lie in the treatment of the attenuation of the UV radiation by clouds and the estimate of the error on the UV index and UV dose.

 
Overview of the main improvements of version 2.0 with respect to version 1.4:

 

Version information
version  date remarks
2.2 22 Mar. 2021   upgrade of the MSG CPP cloud data & extention of a regional map; no reprocessing of earlier data
2.1 15 Dec. 2020   minor upgrade of surface albedo correction; no reprocessing of earlier data
2.0 29 May 2017   major upgrade of the UV index & UV dose processing, with full data reprocessing
1.4 9 Jan. 2012 UV dose processing chain ported to new system
1.3 24 May 2009 UV dose processing updated to new MSG cloud cover area
1.2 April 2008 reprocessed GOME-1 data using GDP-4 ozone (was GDP-3)
1.2 June 2006 switch to Meteosat Second Generation cloud data
1.1 Feb. 2004 updated cloud modification
1.0 April 2003 first operational version

 

Data of versions prior to v2.0 is no longer made available

 


last modified: 24 March 2021
data product contact: Jos van Geffen & Michiel van Weele & Ronald van der A
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