UV index and UV dose: data file structure
data version 2.0

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UV radiation
monitoring:

UV index
Main data product description page

 

HDF data file structure

The data of UV index and UV dose fields is stored in HDF-4 data files.
Simply said, such a file has the following structure:

There are several tools around on the web for viewing and treating HDF files, notably at the The HDF Group Home Page. Software for viewing and reading HDF-4 files is available at the HDF(4) tools page, where you can find a binary distributions for several operating systems (UNIX, Linux, Windows). See in particular the HDF tools by catergory overview, and the HDFview program.

 
Daily UV index & UV dose data file structure

The following table gives as an overview of the HDF-4 file structure for daily UV index & UV dose data.
The first section lists the global attributes of the HDF-4 file,where multiple lines on the "Values" column list the different possibilities for that "Global attribute".
The second section lists the data sets and their attributes.
  * Entries with white background are UV index entries
  * Entries with green background are UV dose entries
  * Entries with page background are entries for both
Other data files, e.g. with monthly and yearly averages, essentially follow the same structure.

 
Global Attribute Value
Product Erythemal UV index
Product Erythemal UV dose (kJ/m2)
Vitamin-D UV dose (kJ/m2)
DNA-damage UV dose (kJ/m2)
Product_date 2012, 6, 16
Product_date_format year, month, day
Product_filename uvief20120616.hdf
Product_filename uvdec20120616.hdf
uvdvc20120616.hdf
uvddc20120616.hdf
Product_version 2.0
Cloud_info Cloud-free datasets only
Cloud_info Cloud-free & cloud-modified datasets
Cloud_modification Derived from MSG CPP surface downwelling solar radiation (SDS) data
No data available: cloud-modification datasets are empty
UV_data_website http://www.temis.nl/uvradiation/UVindex.html
UV_data_description http://www.temis.nl/uvradiation/product/
Authors M. van Weele  &  J. van Geffen
Affiliation KNMI (Royal Netherlands Meteorological Institute)
Email weelevm@knmi.nl  &  geffen@knmi.nl
Data_created_by TM3-DAM, version 4.3  &  temisuv, version 2.0
Ozone_data_source TEMIS operational ozone processing, started 01 July 2002
Number_of_longitudes 1440
Longitude_range -179.8750, 179.8750
Longitude_step 0.25
Number_of_latitudes 720
Latitude_range -89.87500,89.87500
Latitude_step 0.2500000
Earth-Sun_factor 0.9690452
AOD_368nm 0.3
Aerosol_ssa 0.9
UVI_field Erythemal UV index
UVI_error Error on the Erythemal UV index
UVI_units 1   [ 1 UV index unit equals 25 mW/m2 ]
UVI_scale_factor 0.001
UVD_cloud-free Cloud-free Erythemal UV dose
Cloud-free Vitamin-D UV dose
Cloud-free DNA-damage UV dose
UVD_cloud-free_error Error on the cloud-free Erythemal UV dose
Error on the cloud-free Vitamin-D UV dose
Error on the cloud-free DNA-damage UV dose
UVD_cloud-modified Cloud-modified Erythemal UV dose
Cloud-modified Vitamin-D UV dose
Cloud-modified DNA-damage UV dose
UVD_cloud-modified_error Error on the cloud-modified Erythemal UV dose
Error on the cloud-modified Vitamin-D UV dose
Error on the cloud-modified DNA-damage UV dose
UVD_units kJ/m2
UVD_scale_factor 0.001
Cloud_modification_factor Daily average of the cloud modification factor
Cloud_modification_units 1
Cloud_modification_scale_factor 0.001
Ozone_column Assimilated ozone field at local noon
Ozone_units Dobson units (DU)
Ozone_scale_factor 0.1
Surface_albedo GOME-2A based 0.25x0.25 degree surface albedo at 340nm,
                                            interpolated to Product_date
Surface_albedo_version Product algorithm version 2.1
Surface_albedo_data http://www.temis.nl/uvradiation/product/albedo.php
Surface_albedo_correction (1.0-0.25*0.09)/(1.0-0.25*albedo)   [ w.r.t De Bilt=0.09 ]
Surface_elevation GMTED2010 elevation data regridded at 0.250 degree resolution
Surface_elevation_data http://temis.nl/data/gmted2010/
Product_code tiefdv
Product_code tdecdv
tdvcdv
tddcdv
 
Data set
      Attribute
Rank --> dimensions
      Value
UVI_field
      Title
      Units
      Scale_factor
      No_data_value
2 --> 1440 x 720
      Erythemal UV index
      1   [ 1 UV index unit equals 25 mW/m2 ]
      0.001
      -1000 * scale_factor
UVI_error
      Title
      Units
      Scale_factor
      No_data_value
2 --> 1440 x 720
      Error on the Erythemal UV index
      1   [ 1 UV index unit equals 25 mW/m2 ]
      0.001
      -1000 * scale_factor
UVD_cloud-free
      Title
     
     
      Units
      Scale_factor
      No_data_value
2 --> 1440 x 720
      Cloud-free Erythemal UV index
      Cloud-free Vitamin-D UV index
      Cloud-free DNA-damage UV index
      kJ/m2
      0.001
      -1000 * scale_factor
UVD_cloud-free_error
      Title
     
     
      Units
      Scale_factor
      No_data_value
2 --> 1440 x 720
      Error on the cloud-free Erythemal UV index
      Error on the cloud-free Vitamin-D UV index
      Error on the cloud-free DNA-damage UV index
      kJ/m2
      0.001
      -1000 * scale_factor
UVD_cloud-modified
      Title
     
     
      Units
      Scale_factor
      No_data_value
2 --> 1440 x 720
      Cloud-modified Erythemal UV index
      Cloud-modified Vitamin-D UV index
      Cloud-modified DNA-damage UV index
      kJ/m2
      0.001
      -1000 * scale_factor
UVD_cloud-modified_error
      Title
     
     
      Units
      Scale_factor
      No_data_value
2 --> 1440 x 720
      Error on the cloud-modified Erythemal UV index
      Error on the cloud-modified Vitamin-D UV index
      Error on the cloud-modified DNA-damage UV index
      kJ/m2
      0.001
      -1000 * scale_factor
Cloud_modification_factor
      Title
      Units
      Scale_factor
      No_data_value
2 --> 1440 x 720
      Daily average of the cloud modification factor
      1
      0.001
      -1000 * scale_factor
Ozone_column
      Title
      Units
      Scale_factor
2 --> 1440 x 720
      Assimilated ozone field at local noon
      Dobson units (DU)
      0.1
Latitudes
      Title
      Units
      Step
1 --> 720
      Latitudes of grid cell centres
      degrees north
      0.25
Longitudes
      Title
      Units
      Step
1 --> 720
      Longitudes of grid cell centres
      degrees east
      0.25

 
Product code

The list of global attributes in the HDF-4 file contain an entry called product_code. This is a 6-character string introduced for easier post-processing of the data.

 
#char code meaning
1 o source of the ozone data: *
t= TEMIS operational ozone processing, started 01 July 2002
m= Multi-Sensor Re-analysis (MSR) ozone record
2 k kind of UV data product:
i= UV index
d= UV dose
3 a action spectrum:
e= Erythemal
v= Vitamin-D
d= DNA-damage
4 c cloud information:
f= clear-sky data only
c= cloud-modified & clear-sky data
5 t time period of the data: *
d= daily
m= monthly
t= 10-daily
s= seasonally
d= yearly
6 v type of data value: *
v= value
a= average
c= climatology
n= minimum
x= maximum
  *) not all entries listed are currently available

 


last modified: 26 June 2017
data product contact: Jos van Geffen & Michiel van Weele & Roanld van der A
Copyright © KNMI / TEMIS