Dataset
CLASSnmat: monthly, global, gridded night marine air temperature data
Abstract
Climate Linked Atlantic Sector Science (CLASS)nmat is a global dataset of monthly mean night marine air temperature (NMAT) that is produced on a 5° latitude by 5° longitude regular grid and covers the period 1880 to 2019.
The temperature values are taken from version 3.0.0 of the International Comprehensive Ocean-Atmosphere Data Set (ICOADS) for the period 1880-2014 and from version 3.0.2 of ICOADS thereafter. The in situ air temperature readings recorded between one hour after sunset and one hour after sunrise have been extracted from ICOADS and the ship data have been adjusted to reduce the effects of varying thermometer heights. The data have been adjusted from their respective recording heights to each of three reference heights: 2m, 10m and 20m. The air temperature readings have been subjected to a quality-control procedure and values that fail these tests have been excluded. Duplicate values have also been excluded. Additional adjustments have been applied to the data during the Second World War to account for non-standard thermometer exposures on some ships.
The adjusted data have been aggregated into monthly mean values in each grid-cell; uncertainty estimates of these gridded values are also provided. The data have not been interpolated across missing grid boxes. In addition to the absolute temperature values, the gridded data also contain anomalies that are expressed with respect to three climatological averages (1961-90, 1971-2000 and 1981-2010).
Averages across three large-scale domains are provided and these have been calculated from the 10m gridded anomaly data fields and these data are provided in comma-separated values (CSV) files. Uncertainty estimates in these averages are also provided.
Dataset description:
Gridded data:
For each of the reference heights (2m, 10m and 20m) there are three files for each of the base periods. These files contain the absolute gridded data at the respective height, the anomaly values and the uncertainty estimates. The uncertainty estimates consist of three components (correlated, uncorrelated sampling) along with the total uncertainty estimates. Uncertainty values from the climatology estimates are also provided. The climatology files contain the smoothed climatology values along with the 200-member ensemble of climatology realizations, which are used to construct the climatology uncertainties. All uncertainties are 1-sigma values.
Time series data:
Monthly and annual anomaly averages across four regions are provided as CSV files: Global, northern/southern hemispheres and the tropics (30S-30N). These files also contain the corresponding uncertainty values.
Format:
The gridded files are available as NetCDF 4 files, and use a factor 6 compression level. The NetCDF files meet CF-compliance version 1.6. The time series data (large-scale averages) computed from the gridded data are available as comma-separated values (CSV).
Please note that the current public release of ICOADS for the period after 2015 (the near-real-time updates) is version 3.0.1. In CLASSnmat we have used version 3.0.2, which is currently a test version and is not yet publicly available.
Details
| Previous Info: |
2021-01-06 Please note that the current public release of ICOADS for the period after 2015 (the near-real-time updates) is version 3.0.1. … Show More 2021-01-06 Please note that the current public release of ICOADS for the period after 2015 (the near-real-time updates) is version 3.0.1. In CLASSnmat we have used version 3.0.2, which is currently a test version and is not yet publicly available. Show Less |
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| Previously used record identifiers: |
No related previous identifiers.
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| Access rules: |
Access to these data is available to any registered CEDA user. Please Login or Register for an account to gain access.
Use of these data is covered by the following licence: 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: |
Data were produced by the project team and supplied for archiving at the Centre for Environmental Data Analysis (CEDA). |
| Data Quality: |
Data are as given by the data provider, no quality control has been performed by the Centre for Environmental Data Analysis (CEDA)
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| File Format: |
Data are netCDF and BADC-CSV formatted.
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Related Documents
Process overview
| Title | CLASSnmat: a monthly, global, gridded night marine air temperature data |
| Abstract | The temperature values are taken from version 3.0.0 of the International Comprehensive Ocean-Atmosphere Data Set (ICOADS) for the period 1880-2014 and from version 3.0.2 of ICOADS thereafter. The in situ air temperature readings recorded between one hour after sunset and one hour after sunrise have been extracted from ICOADS and the ship data have been adjusted to reduce the effects of varying thermometer heights. The data have been adjusted from their respective recording heights to each of three reference heights: 2m, 10m and 20m. The air temperature readings have been subjected to a quality-control procedure and values that fail these tests have been excluded. Duplicate values have also been excluded. Additional adjustments have been applied to the data during the Second World War to account for non-standard thermometer exposures on some ships. |
| Input Description | None |
| Output Description | None |
| Software Reference | None |
- long_name: 1-sigma sampling uncertainty
- long_name: 1-sigma climatology uncertainty
- long_name: 1-sigma correlated uncertainty
- long_name: 1-sigma coverage uncertainty
- long_name: 1-sigma total uncertainty
- long_name: 1-sigma uncorrelated uncertainty
- long_name: air temperature anomaly
- units: degrees Celsius
- long_name: air temperature anomaly at 10m
- var_id: t10m_anomaly
- units: degrees Celsius
- long_name: air temperature anomaly at 20m
- var_id: t20m_anomaly
- units: degrees Celsius
- long_name: air temperature anomaly at 2m
- var_id: t2m_anomaly
- units: degrees Celsius
- long_name: air temperature at 10m
- var_id: t10m
- units: degrees Celsius
- long_name: air temperature at 10m normal
- var_id: t10m_climatology
- units: degrees Celsius
- long_name: air temperature at 10m simulation
- var_id: t10m_climatology_simulations
- units: degrees Celsius
- long_name: air temperature at 20m
- var_id: t20m
- units: degrees Celsius
- long_name: air temperature at 20m normal
- var_id: t20m_climatology
- units: degrees Celsius
- long_name: air temperature at 20m simulation
- var_id: t20m_climatology_simulations
- units: degrees Celsius
- var_id: t2m
- long_name: air temperature at 2m
- units: degrees Celsius
- long_name: air temperature at 2m normal
- var_id: t2m_climatology
- units: degrees Celsius
- long_name: air temperature at 2m simulation
- var_id: t2m_climatology_simulations
- var_id: bnds
- long_name: bnds
- units: degrees Celsius
- long_name: climatology uncertainty at 10m
- var_id: t10m_climatology_uncertainty
- units: degrees Celsius
- long_name: climatology uncertainty at 20m
- var_id: t20m_climatology_uncertainty
- units: degrees Celsius
- long_name: climatology uncertainty at 2m
- var_id: t2m_climatology_uncertainty
- units: degrees Celsius
- long_name: correlated uncertainty at 10m
- var_id: t10m_correlated_uncertainty
- units: degrees Celsius
- long_name: correlated uncertainty at 20m
- var_id: t20m_correlated_uncertainty
- units: degrees Celsius
- long_name: correlated uncertainty at 2m
- var_id: t2m_correlated_uncertainty
- units: degrees_north
- var_id: latitude
- long_name: latitude
- units: degrees_north
- var_id: latitude_bnds
- long_name: latitude axis boundaries
- units: degrees_north
- var_id: latitude_bnds
- units: degrees_north
- var_id: latitude_vector_1
- units: degrees_north
- var_id: latitude_vector_2
- long_name: location_index_1
- var_id: location_index_1
- long_name: location_index_2
- var_id: location_index_2
- units: degrees_east
- var_id: longitude
- long_name: longitude
- units: degrees_east
- var_id: longitude_bnds
- long_name: longitude axis boundaries
- units: degrees_east
- var_id: longitude_bnds
- units: degrees_east
- var_id: longitude_vector_1
- units: degrees_east
- var_id: longitude_vector_2
- units: month
- long_name: month
- var_id: month
- units: degrees Celsius
- long_name: sampling uncertainty at 10m
- var_id: t10m_sampling_uncertainty
- units: degrees Celsius
- long_name: sampling uncertainty at 20m
- var_id: t20m_sampling_uncertainty
- units: degrees Celsius
- long_name: sampling uncertainty at 2m
- var_id: t2m_sampling_uncertainty
- long_name: simulation
- var_id: simulation
- units: K2
- var_id: t10m_cov
- units: K2
- var_id: t20m_cov
- units: K2
- var_id: t2m_cov
- long_name: time
- var_id: time
- var_id: time_bnds
- units: degrees Celsius
- long_name: total air temperature anomaly uncertainty at 10m
- var_id: t10m_anomaly_uncertainty
- units: degrees Celsius
- long_name: total air temperature anomaly uncertainty at 20m
- var_id: t20m_anomaly_uncertainty
- units: degrees Celsius
- long_name: total air temperature anomaly uncertainty at 2m
- var_id: t2m_anomaly_uncertainty
- units: degrees Celsius
- long_name: total uncertainty at 10m
- var_id: t10m_total_uncertainty
- units: degrees Celsius
- long_name: total uncertainty at 20m
- var_id: t20m_total_uncertainty
- units: degrees Celsius
- long_name: total uncertainty at 2m
- var_id: t2m_total_uncertainty
- units: degrees Celsius
- long_name: uncorrelated uncertainty at 10m
- var_id: t10m_uncorrelated_uncertainty
- units: degrees Celsius
- long_name: uncorrelated uncertainty at 20m
- var_id: t20m_uncorrelated_uncertainty
- units: degrees Celsius
- long_name: uncorrelated uncertainty at 2m
- var_id: t2m_uncorrelated_uncertainty
- long_name: year
Co-ordinate Variables
Temporal Range
1880-01-01T00:00:00
2019-12-31T23:59:59
Geographic Extent
90.0000° |
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-180.0000° |
180.0000° |
|
-90.0000° |