UK Daily Temperature data - Columns in the TD table

Table Description - Columns in the TD table - How to start filtering the rows of data out

The surface observation data are in a simple ASCII format.

Table Description:

This entity contains maximum and minimum temperatures measured over a period of up to 24 hours. ob_end_time and ob_hour_count define the observation period. Attributes with different time-scales will not be compressed into a single row. For air temperatures, the observation period will usually be one of the following: 09-09Z, 09-21Z, 21-09Z. For minimum grass temperature and minimum concrete temperature ob_end_time is most usually 0900. Where the period of exposure is known to be 21-09Z, then ob_hour_count = 12. For some stations, the period of exposure is not known, but could be as much as 09-09Z, so a nominal ob_hour_count = 12 is used. MIDAS will store rows in this table using climatological station number, i.e. id_type = 'DCNN'. If the station does not have a DCNN, it will use WMO number, i.e. id_type = 'WMO'.

Please note that although observing practice "throws back" certain parameters to the previous day (e.g. maximum temperature) these are not thrown back within the MIDAS system, but are entered in the MIDAS system as the values recorded at the observation time for the record.

Columns in the TD table:

For the convenience of users, the TD file column headers are available for download in Excel or as a comma separated text file

PK Attribute Description / Units / Precision
* ob_end_time Date and time at end of observation
* id_type Identifier type
* id  
* ob_hour_count Observation hour count
* version_num Observation version number - Use the row with '1', as this has been quality checked by the Met Office
* met_domain_name Message type
  src_id Unique source identifier or station site number
  rec_st_ind State indicator for the record**
  max_air_temp Maximum air temperature
Unit=1 deg C to the nearest 0.1 deg C
  min_air_temp Minimum air temperature
Unit=1 deg C to the nearest 0.1 deg C
  min_grss_temp Minimum grass temperature
Unit=1 deg C to the nearest 0.1 deg C
  min_conc_temp Minimum concrete temperature
Unit=1 deg C to the nearest 0.1 deg C
  max_air_temp_q QC code - max air temperature**
  min_air_temp_q QC code - min air temperature**
  min_grss_temp_q QC code - min grass temp**
  min_conc_temp_q QC code - min concrete temp**
  meto_stmp_time Met Office receipt stamp time
  midas_stmp_etime Elapsed time to storage in MIDAS
  max_air_temp_j Descriptor - max air temp**
  min_air_temp_j Descriptor - min air temp**
  min_grss_temp_j Descriptor - min grass temp**
  min_conc_temp_j Descriptor - min concrete temp**

** Details available to registered users only.

More information about the Met Office surface data is available in the documentation provided by the Met Office.

How to start filtering the rows of data out:

  1. As the data arrive at the Met Office it undergoes quality control to check that the data are correct and consistent with the surrounding data points. Whether the process has occured or not is indicated by the version number (1 is the one to use as indicated in the table above).

  2. To show the progress of the data through the quality control the various variables will have an associated _q value (e.g. max_air_temp_q). This _q value will have different values for each record (see details in table above).

  3. While the Met Office MIDAS system overwrites the existing entry in their database the BADC's MIDAS entries do not as the BADC takes snapshots of the the MIDAS database from time to time leading to duplicate entries occuring in our archive. If duplicate records are found, check the associated meto_stmp_time to determine which record is the most recent one - this is the one to use and the other(s) can be ignored.