Dataset
Water tracer precipitation output from the Met Office Unified Model (GAL9.0) for 1985-2014
Abstract
This dataset contains global water tracer precipitation from a historical simulation of the Met Office Unified Model (UM) for the 30 year period, 1985 to 2014. The water tracer data can be used to track the source evaporative properties of the model's precipitation and is used in the following paper:
McLaren, A. J., Sime, L. C., Wilson, S., Ridley, J., Gao, Q., Gorguner, M., Line, G., Werner, M., and Valdes, P.: Implementation of water tracers in the Met Office Unified Model, Geosci. Model Dev., 18, 8129-8142, https://doi.org/10.5194/gmd-18-8129-2025, 2025.
The simulation is atmosphere only, with prescribed sea surface temperature and sea ice starting in 1979. The ‘N96’ horizontal resolution version of the UM is used which has 192 longitude points by 144 latitude points, with a mid-latitude resolution of 135km. There are 85 vertical levels with 50 levels below 18km and a fixed model lid at 85km above sea level. The scientific configuration is GAL9.0 and the UM version is 13.3.
In the dataset, the different water tracers have an associated 'water tracer number'. These are:
1 = Total precipitation
2 = Precipitation that has been sourced from Northern Hemisphere (NH) sea ice sublimation
3 = Precipitation that has been sourced from Southern Hemisphere (SH) sea ice sublimation
4 = Precipitation that has been sourced from NH open ocean evaporation
5 = Precipitation that has been sourced from SH open ocean evaporation
6 = Precipitation that has been sourced from NH land evapotranspiration
7 = Precipitation that has been sourced from SH (north of 60S) land evapotranspiration
8 = Precipitation that has been sourced from SH (south of 60S) land evapotranspiration
9-23 = Scaled flux water tracer precipitation (see McLaren et al. 2025 for details)
These are fully documented in McLaren et al. (2025).
Global climatological seasonal means for the 30 year period, 1985 - 2014, are provided.
Details
| Previous Info: |
No news update for this record
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| Previously used record identifiers: |
No related previous identifiers.
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| Access rules: |
Public data: access to these data is available to both registered and non-registered users.
Use of these data is covered by the following licence(s): http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/ When using these data you must cite them correctly using the citation given on the CEDA Data Catalogue record. |
| Data lineage: |
Monthly mean water tracer precipitation was output from the Met Office UM simulation. This was then used to calculate the 30-year seasonal mean data using the Python package Iris by the project team before uploading to CEDA. |
| Data Quality: |
No information provided - see McLaren et al. , 2025: Implementation of Water Tracers in the Met Office Unified Model
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| File Format: |
Data is NetCDF formatted
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Process overview
| Title | Met Office Unified Model version 13.3, configuration GAL9.0 |
| Abstract | The scientific configuration is GAL9.0 and the UM version is 13.3. The ‘N96’ horizontal resolution version of the UM is used which has 192 longitude points by 144 latitude points, with a mid-latitude resolution of 135km. There are 85 vertical levels with 50 levels below 18km and a fixed model lid at 85km above sea level. |
| Input Description | None |
| Output Description | None |
| Software Reference | None |
- units: 1
- var_id: pseudo_level
- long_name: Water_tracer_number
- units: kg m-2 s-1
- var_id: m01s33i176
- long_name: Water_tracer_precipitation_flux
- units: hours
- standard_name: forecast_period
- var_id: forecast_period
- var_id: forecast_period_bnds
- units: hours
- standard_name: forecast_reference_time
- var_id: forecast_reference_time
- var_id: latitude_longitude
- long_name: month
- var_id: month
- long_name: season
- var_id: season
- var_id: time_climatology
Co-ordinate Variables
- units: degrees_north
- standard_name: latitude
- var_id: latitude
- units: degrees_east
- standard_name: longitude
- var_id: longitude
- standard_name: time
- var_id: time
- units: hours
Temporal Range
1985-01-01T00:00:00
2014-12-30T00:00:00
Geographic Extent
90.0000° |
||
-180.0000° |
180.0000° |
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-90.0000° |