The HADRT2.2 data are global monthly fields of radiosonde temperature anomalies at standard pressure levels on a 10 degree latitude by 20 degree longitude grid from 1958 to 2000. Anomalies are calculated with respect to 1971-1990 climatology. Anomalies are available for 9 standard levels (850, 700, 500, 300, 200, 150, 100, 50, 30hPa) as well as tropospheric (850 - 300hPa) and stratospheric (150 - 30hPa) averages. The data are degree Celsius anomalies from 1970-1990 means. Anomalies are calculated for each of about 200 sonde stations worldwide and grid values derived from these. HADRT2.2 is an eigenvector reconstructed grid data set from 1958 - 2000, on a 10 degree latitude by 20 degree longitude grid, created from HadRT2.1. The eigenvector reconstruction was used to infill missing seasons or years in boxes with 70% of seasonal or annual data available. This dataset has been superseded by the HadAT dataset also available from CEDA.

The HADRT2.3 data are global monthly fields of radiosonde temperature anomalies at standard pressure levels on a 5 degree latitude by 10 degree longitude grid from 1958 to 2000. Anomalies are calculated with respect to 1971-1990 climatology. Anomalies are available for 9 standard levels (850, 700, 500, 300, 200, 150, 100, 50, 30hPa) as well as tropospheric (850 - 300hPa) and stratospheric (150 - 30hPa) averages. The data are degree Celsius anomalies from 1970-1990 means. Anomalies are calculated for each of about 200 sonde stations worldwide and grid values derived from these. HADRT2.3 is a globally complete dataset based on HadRT2.1 1958-2000, but with gaps filled in by reference to the second derivative of the corresponding NCEP reanalysis temperature fields, using the Laplacian technique of Reynolds, 1988: A Real-Time Global Sea Surface Temperature Analysis. J. Climate (see docs for a link to this publication) This dataset has been superseded by the HadAT dataset also available from CEDA.

The HadAT1 data are global radiosonde gridded temperature anomalies at standard levels (850, 700, 500, 300, 200, 150, 100, 50, and 30hPa) in the troposphere and in the lower stratosphere from 1958 to December 2002. This monthly timeseries are available on a 10 degree longitude by 5 degree latitude basis. This dataset supersedes the HadRT dataset. All values are anomalies relative to the monthly 1966-95 climatology.

This dataset holds Northern Hemisphere (north of 15N) gridded (5° latitude by 10° longitude grid) series of monthly Mean Sea Level Pressure fields. The data are available for the period 1873 to 2005. The data was supplied by the Met Office, Hadley Centre.

The HADRT2.1 data are global monthly fields of radiosonde temperature anomalies at standard pressure levels on a 5 degree latitude by 10 degree longitude grid from 1958 to July 2004. Anomalies are calculated with respect to 1971-1990 climatology. Anomalies are available for 9 standard levels (850, 700, 500, 300, 200, 150, 100, 50, 30hPa) as well as tropospheric (850 - 300hPa) and stratospheric (150 - 30hPa) averages. The data are degree Celsius anomalies from 1970-1990 means. Anomalies are calculated for each of about 200 sonde stations worldwide and grid values derived from these. HADRT2.1 is as HadRT2.0 but with bias corrections made to many station time series world-wide. The adjustments were calculated by reference to MSU data products, but only for known changes in instrumental or operational procedures for the period post 1979. No data are available for the 30hPa level in this version. This dataset has been superseded by the HadAT dataset also available from CEDA.

The HADRT2.2u data are global monthly fields of radiosonde temperature anomalies at standard pressure levels on a 10 degree latitude by 20 degree longitude grid from 1958 to 2000. Anomalies are calculated with respect to 1971-1990 climatology. Anomalies are available for 9 standard levels (850, 700, 500, 300, 200, 150, 100, 50, 30hPa) as well as tropospheric (850 - 300hPa) and stratospheric (150 - 30hPa) averages. The data are degree Celsius anomalies from 1970-1990 means. Anomalies are calculated for each of about 200 sonde stations worldwide and grid values derived from these. HADRT2.2u are as HADRT2.2 but created from HADRT2.0. This dataset has been superseded by the HadAT dataset also available from CEDA.

The Met Office Hadley Centre's sea surface temperature data set, HadSST2, replaces the Met Office Historical Sea Surface Temperature dataset (MOHSST6) and is a monthly global field of SST (Sea Surface Temperature) on a 5 deg latitude by 5 deg longitude grid from 1850 to August 2013. The data are neither interpolated nor variance adjusted. The SST data are taken from the International Comprehensive Ocean-Atmosphere Data Set, ICOADS, from 1850 to 1997 and from the NCEP-GTS from 1998 to the present. HadSST2 is produced by taking in-situ measurements of SST from ships and buoys, rejecting measurements which which fail quality checks, converting the measurements to anomalies by subtracting climatological values from the measurements, and calculating a robust average of the resulting anomalies on a 5° by 5° degree monthly grid. After gridding the anomalies, bias corrections are applied to remove spurious trends caused by changes in SST measuring practices before 1942. The uncertainties due to under-sampling have been calculated for the gridded monthly data as have the uncertainties on the bias corrections. This dataset include: - SST anomaly data (HadSST2_SST_1850on.txt.gz) - 1961-1990 Climatology (HadSST2_climatology_5x5_1961_1990.txt) - numbers of observations used to calculate the average (HadSST2_nobs_1850on.txt.gz) - Estimates on the measurement and sampling errors on the SST data (HadSST2_m_and_s_errors_1850on.txt.gz) - bias-adjusted data using bias adjustments which represent the 97.5 percent and 2.5 percent confidence levels of the estimated errors on the adjustments (HadSST2_97.5_pct_bias_1850on.txt.gz and HadSST2_2.5_pct_bias_1850on.txt.gz). - Files showing the correction applied to the data e.g.: HadSST2_bucket_correction_median.txt.gz - the corrections applied to the data 1850-1941 HadSST2_bucket_correction_2.5pc.txt.gz - the lower bound of the 95% confidence range of the uncertainties 1850-1941 HadSST2_bucket_correction_97.5pc.txt.gz - the upper bound of the 95% confidence range of the uncertainties 1850-1941 A 1 degree version of HadSST2 is also available. Data were provided by the Met Office Hadley Centre. Dataset was produced by the Hadley Centre in collaboration with ICOADS.

MOHSST, (Met Office Historical Sea-Surface Temperature) is a gridded dataset of sea-surface temperature anomalies covering the period 1856-2006. MOHSST has now been superceeded by HadSST2. We now recommend use of HadSST2 instead of MOHSST for all purposes. MOHSST is only still available in case it is needed for direct comparison with earlier work where MOHSST was used. MOHSST is produced by taking in-situ measurements of SST from ships and buoys, rejecting measurements which which fail quality checks, converting the measurements to anomalies by subtracting climatological values from the measurements, and averaging the resulting anomalies on a 5 by 5 degree monthly grid. Up to 1996 the measurements used are those in the U.K. Marine Data Bank; more recent years use data coming in through the GTS. After gridding the anomalies, bias corrections are applied to remove spurious trends caused by changes in SST measuring practices, and the data are smoothed to reduce noise. The data were provided by the Met Office Hadley Centre.

The HadAT0 data are global radiosonde gridded temperature anomalies at standard levels (850, 700, 500, 300, 200, 150, 100, 50, and 30hPa) in the troposphere and in the lower stratosphere from 1958 to December 2002. This monthly timeseries are available on a 10 degree longitude by 5 degree latitude basis. This dataset supersedes the HadRT dataset. All values are anomalies relative to the monthly 1966-95 climatology.

CRUTEM (Climatic Research Unit TEMperature) is a gridded dataset of global historical near-surface air temperature anomalies over land at a monthly timescale. It is a collaborative product of the Climatic Research Unit at the University of East Anglia, the Met Office Hadley Centre and the National Centre for Atmospheric Science. CRUTEM also contributes the land air temperature station data to the global (land and ocean) temperature dataset called HadCRUT. CRUTEM5 is the fifth major version of the dataset, covering the time period from 1850, with a spatial resolution of 5° latitude by 5° longitude and a monthly-mean time resolution. The gridded temperature anomaly fields are based on a compilation of monthly-mean temperature observational records from weather stations. This compilation contains 10639 station records, but only 7983 records had the necessary coverage to be used for producing the gridded dataset. Anomalies are differences from average conditions in the 1961-1990 period. Hemispheric and global mean time series of land air temperature anomalies are also provided.