This dataset holds Northern Hemisphere (north of 15 deg. N) daily and monthly series of 1000-500hPa Geopotential Height Thickness Daily and Monthly Series. The data is gridded on a 5x10 degree grid. The data is available for the period 1945 to 2005. The geopotential thickness between pressure levels — difference of the 1000 hPa and 500 hPa geopotential heights for example — is proportional to mean virtual temperature in that layer. The data is supplied by the Met Office, Hadley Centre.

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 J. Climate (see docs for a link to this publication) This dataset has been superseded by the HadAT dataset also available from CEDA.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 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 This dataset has been superseded by the HadAT dataset also available from CEDA.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 Met Office Hadley Centre produced the HadSLP1 dataset which replaces the Global Mean Sea Level Pressure (GMSLP) data sets, and is a unique combination of monthly globally-complete fields of land and sea pressure observations a 5 degree latitude-longitude grid from 1871 to 1998. The advantages of HadSLP1 over GMSLP2 are an improved land station data base, new interpolation scheme and the incorporation of local detail while safeguarding against random errors. Like GMSLP2, HadSLP1 was developed by Tracy Basnett and David Parker, in collaboration with R.J. Allan (previously at CSIRO and now at the Met Office) and M.J. Salinger (NIWA). Marine observations were taken from the Met Office Marine Data Bank (MDB) and from the NOAA Comprehensive Ocean-Atmosphere Data Set (COADS) (Woodruff et al, 1987). The MDB data were given priority in the blend, which is described in Basnett and Parker (1997). Land observations are a combination of data obtained from CSIRO (Australia), NIWA (New Zealand), CRU (University of East Anglia), GHCN, and operationally-received "CLIMAT" messages. The latter were used mainly for updating station series and for the Arctic. HadSLP1 pressures are reconstructed using a reduced-space optimal interpolation procedure, followed by superposition of quality-improved gridded observations onto the reconstructions to restore local detail.

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.

MOHMAT, (Met Office Historical Marine Air Temperature) is a gridded dataset of marine air temperature anomalies covering the period 1856-2006. The current version of the dataset is MOHMAT4, which is described in reference below (under Doc tab). MOHMAT is produced by taking in-situ measurements of MAT from ships and buoys, rejecting measurements 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. Note that only night-time data are used, because day-time data are corrupted by heat island effects. 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. MOHMAT is no longer updated. After gridding the anomalies, bias corrections are applied to remove spurious trends caused by changes in ship deck heights and various unusual operational practices, and the data are smoothed to reduce noise. The data are provided by the Met Office.

The HADRT2.0 (unadjusted) 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. This dataset has been superseded by the HadAT dataset also available from CEDA.

The HADRT2.1s 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. HADRT2.1s is a combination of HadRT2.0 in the troposphere (up to and including 200hPa) and HadRT2.1 in the stratosphere (above 200hPa). This dataset has been superseded by the HadAT dataset also available from CEDA.

This dataset holds Northern Hemisphere (north of 15N) gridded (5° latitude by 10° longitude grid) series of daily Mean Sea Level Pressure fields. The data are available for the period 1881 to 2005. The data was supplied by the Met Office, Hadley Centre.

This dataset holds Northern Hemisphere (north of 15 deg. N) daily and monthly series of 500 hPa geopotential height fields. The data is gridded on a 5x10 degree grid. The data is available for the period 1945 to 2005. The data is supplied by the Met Office, Hadley Centre.