HadUK-Grid is a collection of gridded climate variables derived from the network of UK land surface observations. The data have been interpolated from meteorological station data onto a uniform grid to provide complete and consistent coverage across the UK. These data at 1 km resolution have been averaged across a set of discrete geographies defining UK river basins consistent with data from UKCP18 climate projections. The dataset spans the period from 1862 to 2019, but the start time is dependent on climate variable and temporal resolution. The gridded data are produced for daily, monthly, seasonal and annual timescales, as well as long term averages for a set of climatological reference periods. Variables include air temperature (maximum, minimum and mean), precipitation, sunshine, mean sea level pressure, wind speed, relative humidity, vapour pressure, days of snow lying, and days of ground frost. This data set supersedes the previous versions of this dataset which also superseded UKCP09 gridded observations. Subsequent versions may be released in due course and will follow the version numbering as outlined by Hollis et al. (2018, see linked documentation). For this version of note is that historical data recovery has improved monthly rainfall 1862-1910, daily rainfall 1883-1910, monthly temperature 1900-1909, and additional sunshine grids for 1919-1928 have been added. The primary purpose of these data are to facilitate monitoring of UK climate and research into climate change, impacts and adaptation. The datasets have been created by the Met Office with financial support from the Department for Business, Energy and Industrial Strategy (BEIS) and Department for Environment, Food and Rural Affairs (DEFRA) in order to support the Public Weather Service Customer Group (PWSCG), the Hadley Centre Climate Programme, and the UK Climate Projections (UKCP18) project. The data recovery activity to supplement 19th and early 20th Century data availability has also been funded by the Natural Environment Research Council (NERC grant ref: NE/L01016X/1) project "Analysis of historic drought and water scarcity in the UK". The dataset is provided under Open Government Licence.

These datasets contain total, non-fluorescent and bio-fluorescent aerosol particle concentrations and particle size distributions collected with University of Manchester WIBS-4M an MBS-M spectrometers during the Towards a UK Airborne Bioaerosol Climatology (BIOARC) project. Data was collected at the following ground sites: Cardington Meteorological Research Unit: MBS-M, 11/04/2019 - 09/06/2019 Chilbolton Observatory: WIBS-4D, 14/05/2019 - 14/06/2019 Weybourne Atmospheric Observatory: WIBS-4M, 03/06/2019 - 01/08/2019 Chilbolton Observatory: WIBS-4M, 10/09/2020 - 21/06/2021 Weybourne Atmospheric Observatory: MBS-M, 15/09/2020 - 03/11/2019 Weybourne Atmospheric Observatory: MBS-M, 15/04/2021 - 16/07/2021 NERC reference NE/S002049/1

This dataset contains the data used to plot results found in the Suppression of surface ozone by an aerosol-inhibited photochemical ozone regime journal article published in Nature Geoscience. The simulations were run using the GEOS-Chem V12.8 chemical transport model at 0.5-degree horizontal resolution over the domain 170W-170E, 10S-60N using 2017 meteorological data for 1750, 1970 and 2014 emissions scenarios. July 2017 GEOS-FP (forward-processing) meteorological fields were used for all simulations. Three experimental runs were performed using 1750 emissions; no sea salt, no dust and no biomass burning emissions. One experiment was run using 1970 emissions; no shipping emissions. Three experimental runs were performed using 2014 emissions with three different HO2 uptake coefficients; 0.1, 0.05 and 0 (no uptake). Surface data is archived for all simulations, additionally, data at pressure levels 200 hPa, and 500 hPa 800 hPa were archived for 2014.

HadUK-Grid is a collection of gridded climate variables derived from the network of UK land surface observations. The data have been interpolated from meteorological station data onto a uniform grid to provide complete and consistent coverage across the UK. The dataset at 12 km resolution is derived from the associated 1 km x 1 km resolution to allow for comparison to data from climate projections. The dataset spans the period from 1836 to 2021, but the start time is dependent on climate variable and temporal resolution. The gridded data are produced for daily, monthly, seasonal and annual timescales, as well as long term averages for a set of climatological reference periods. Variables include air temperature (maximum, minimum and mean), precipitation, sunshine, mean sea level pressure, wind speed, relative humidity, vapour pressure, days of snow lying, and days of ground frost. This data set supersedes the previous versions of this dataset which also superseded UKCP09 gridded observations. Subsequent versions may be released in due course and will follow the version numbering as outlined by Hollis et al. (2018, see linked documentation). The changes for v1.1.0.0 HadUK-Grid datasets are as follows: * The addition of data for calendar year 2021 * The addition of 30 year averages for the new reference period 1991-2020 * An update to 30 year averages for 1961-1990 and 1981-2010. This is an order of operation change. In this version 30 year averages have been calculated from the underlying monthly/seasonal/annual grids (grid-then-average) in previous version they were grids of interpolated station average (average-then-grid). This order of operation change results in small differences to the values, but provides improved consistency with the monthly/seasonal/annual series grids. However this order of operation change means that 1961-1990 averages are not included for sfcWind or snowlying variables due to the start date for these variables being 1969 and 1971 respectively. * A substantial new collection of monthly rainfall data have been added for the period before 1960. These data originate from the rainfall rescue project (Hawkins et al. 2022) and this source now accounts for 84% of pre-1960 monthly rainfall data, and the monthly rainfall series has been extended back to 1836. Net changes to the input station data used to generate this dataset: -Total of 122664065 observations -118464870 (96.5%) unchanged -4821 (0.004%) modified for this version -4194374 (3.4%) added in this version -5887 (0.005%) deleted from this version The primary purpose of these data are to facilitate monitoring of UK climate and research into climate change, impacts and adaptation. The datasets have been created by the Met Office with financial support from the Department for Business, Energy and Industrial Strategy (BEIS) and Department for Environment, Food and Rural Affairs (DEFRA) in order to support the Public Weather Service Customer Group (PWSCG), the Hadley Centre Climate Programme, and the UK Climate Projections (UKCP18) project. The output from a number of data recovery activities relating to 19th and early 20th Century data have been used in the creation of this dataset, these activities were supported by: the Met Office Hadley Centre Climate Programme; the Natural Environment Research Council project "Analysis of historic drought and water scarcity in the UK"; the UK Research & Innovation (UKRI) Strategic Priorities Fund UK Climate Resilience programme; The UK Natural Environment Research Council (NERC) Public Engagement programme; the National Centre for Atmospheric Science; National Centre for Atmospheric Science and the NERC GloSAT project; and the contribution of many thousands of public volunteers. The dataset is provided under Open Government Licence.

HadUK-Grid is a collection of gridded climate variables derived from the network of UK land surface observations. The data have been interpolated from meteorological station data onto a uniform grid to provide complete and consistent coverage across the UK. These data at 1 km resolution have been averaged across a set of discrete geographies defining UK countries consistent with data from UKCP18 climate projections. The dataset spans the period from 1836 to 2021, but the start time is dependent on climate variable and temporal resolution. The gridded data are produced for daily, monthly, seasonal and annual timescales, as well as long term averages for a set of climatological reference periods. Variables include air temperature (maximum, minimum and mean), precipitation, sunshine, mean sea level pressure, wind speed, relative humidity, vapour pressure, days of snow lying, and days of ground frost. This data set supersedes the previous versions of this dataset which also superseded UKCP09 gridded observations. Subsequent versions may be released in due course and will follow the version numbering as outlined by Hollis et al. (2018, see linked documentation). The changes for v1.1.0.0 HadUK-Grid datasets are as follows: * The addition of data for calendar year 2021 * The addition of 30 year averages for the new reference period 1991-2020 * An update to 30 year averages for 1961-1990 and 1981-2010. This is an order of operation change. In this version 30 year averages have been calculated from the underlying monthly/seasonal/annual grids (grid-then-average) in previous version they were grids of interpolated station average (average-then-grid). This order of operation change results in small differences to the values, but provides improved consistency with the monthly/seasonal/annual series grids. However this order of operation change means that 1961-1990 averages are not included for sfcWind or snowlying variables due to the start date for these variables being 1969 and 1971 respectively. * A substantial new collection of monthly rainfall data have been added for the period before 1960. These data originate from the rainfall rescue project (Hawkins et al. 2022) and this source now accounts for 84% of pre-1960 monthly rainfall data, and the monthly rainfall series has been extended back to 1836. Net changes to the input station data used to generate this dataset: -Total of 122664065 observations -118464870 (96.5%) unchanged -4821 (0.004%) modified for this version -4194374 (3.4%) added in this version -5887 (0.005%) deleted from this version The primary purpose of these data are to facilitate monitoring of UK climate and research into climate change, impacts and adaptation. The datasets have been created by the Met Office with financial support from the Department for Business, Energy and Industrial Strategy (BEIS) and Department for Environment, Food and Rural Affairs (DEFRA) in order to support the Public Weather Service Customer Group (PWSCG), the Hadley Centre Climate Programme, and the UK Climate Projections (UKCP18) project. The output from a number of data recovery activities relating to 19th and early 20th Century data have been used in the creation of this dataset, these activities were supported by: the Met Office Hadley Centre Climate Programme; the Natural Environment Research Council project "Analysis of historic drought and water scarcity in the UK"; the UK Research & Innovation (UKRI) Strategic Priorities Fund UK Climate Resilience programme; The UK Natural Environment Research Council (NERC) Public Engagement programme; the National Centre for Atmospheric Science; National Centre for Atmospheric Science and the NERC GloSAT project; and the contribution of many thousands of public volunteers. The dataset is provided under Open Government Licence.

This is the HadISDH marine 1.1.0.2020f version of the Met Office Hadley Centre Integrated Surface Dataset of Humidity (HadISDH). HadISDH-marine s a near-global gridded monthly mean marine surface humidity climate monitoring product. It is created from in situ observations of air temperature and dew point temperature from ships. The observations have been quality controlled and bias-adjusted. Uncertainty estimates for observation issues and gridbox sampling are provided (see data quality statement section below). The data are provided by the Met Office Hadley Centre and this version spans 1/1/1973 to 31/12/2020. The data are monthly gridded (5 degree by 5 degree) fields. Products are available for temperature and six humidity variables: specific humidity (q), relative humidity (RH), dew point temperature (Td), wet bulb temperature (Tw), vapour pressure (e), dew point depression (DPD). This version extends the 1.0.0.2019f version to the end of 2020 and constitutes a minor update to HadISDH due to change in method for calculating gridbox monthly means. All other processing steps for HadISDH remain identical. Users are advised to read the update document in the Docs section for full details. To keep informed about updates, news and announcements follow the HadOBS team on twitter @metofficeHadOBS. For more detailed information e.g bug fixes, routine updates and other exploratory analysis, see the HadISDH blog: http://hadisdh.blogspot.co.uk/ References: When using the dataset in a paper please cite the following papers (see Docs for link to the publications) and this dataset (using the "citable as" reference): Willett, K. M., Dunn, R. J. H., Kennedy, J. J. and Berry, D. I., 2020: Development of the HadISDH marine humidity climate monitoring dataset. Earth System Sciences Data, 12, 2853-2880, https://doi.org/10.5194/essd-12-2853-2020 Freeman, E., Woodruff, S. D., Worley, S. J., Lubker, S. J., Kent, E. C., Angel, W. E., Berry, D. I., Brohan, P., Eastman, R., Gates, L., Gloeden, W., Ji, Z., Lawrimore, J., Rayner, N. A., Rosenhagen, G. and Smith, S. R., ICOADS Release 3.0: A major update to the historical marine climate record. International Journal of Climatology. doi:10.1002/joc.4775.

This dataset contains water budget and Lagrangian analysis of the tropical tropopause from climate model simulations and Lagrangian trajectory calculations. This study was conducted to understand better the role of convection as water vapour enters the tropical stratosphere (above about 17.4km), in particular in future scenarios. The atmosphere component of HadGEM3, Global Atmosphere (GA) 7.0, was run for three different scenarios. Based on the SPARC Quasi-Biennial Oscillation initiative (QBOi) experiments 2,3,4, these force the atmosphere model with year 2002 conditions (e.g. of solar radiation and sea surface temperatures) every year for 21 years, so that each year experiences identical boundary conditions. The first scenario has no modifications (as a control), the second has doubled CO2 concentrations and sea surface temperatures (SSTs) are increased by 2K, andthe third has quadrupled CO2 concentrations and SSTs are increased by 4K. Simulations were allowed 10 years to stabilise to their modified forcing conditions and the final 11 years were analysed further. These simulations were chosen because they give a simplified indication of how the atmosphere might change in the 21st century. A second component to this dataset is estimates of water vapour entering the stratosphere with the available output. For this, climate model output was used for Lagrangian calculations which were conducted with the OFFLINE trajectory model. Records includes: -increments of all model processes that affect water vapour and ice (to get a full water budget) at grid points around the tropical tropopause (altitude of 17.4km and 18.0km, 40degS - 40degN and 180W - 180E) as monthly means of 6 hourly instantaneous values across the first two years after stabilisation. - locations and timing of model grid points above the minimum saturation mixing ratio in the vertical profile (the dry point) that exhibit convective ice injection (fast transport of ice by strong cloud processes) - monthly mean values of estimates of water vapour concentration above the tropical tropopause. These values include the HadGEM3 calculation, and proxies based on the dry point or on Lagrangian (trajectory-following) calculations of water vapour passing through the tropical tropopause. These records are analysed in: Smith, J. W., Bushell, A. C., Butchart.,N. , Haynes, P. H., Maycock, A. C., The effect of convective injection of ice on stratospheric water vapor in a changing climate, Geophysical Research Letters, submitted 12/21. Links for further information: HadGEM3: https://www.metoffice.gov.uk/research/approach/modelling-systems/unified-model/climate-models/hadgem3 QBOi experiment: Butchart, N., Anstey, J. A., Hamilton, K., Osprey, S., McLandress, C., Bushell, A. C., … Yukimoto, S. (2018). Overview of experiment design and comparison of models participating in phase 1 of the SPARC Quasi-Biennial Oscillation initiative (QBOi). Geoscientific Model Development, 11(3), 1009–1032. https://doi.org/10.5194/gmd-11-1009-2018 OFFLINE trajectory model: http://www.met.reading.ac.uk/~swrmethn/offline/

This dataset contains measurements taken from the Fourier Transform Infra-Red (FTIR instrument location at the Weybourne Atmospheric Observatory. The instrument measures CH4, N2O, CO and CO2. The Weybourne Atmospheric Observatory (WAO) is a Regional station in the Global Atmosphere Watch (GAW) programme of the World Meteorological Organization (WMO). It is situated on the North Norfolk coast (52°57’02’’N, 1°07’19’’E, 15 m asl).

HadUK-Grid is a collection of gridded climate variables derived from the network of UK land surface observations. The data have been interpolated from meteorological station data onto a uniform grid to provide complete and consistent coverage across the UK. These data at 1 km resolution have been averaged across a set of discrete geographies defining UK administrative regions consistent with data from UKCP18 climate projections. The dataset spans the period from 1862 to 2020, but the start time is dependent on climate variable and temporal resolution. The gridded data are produced for daily, monthly, seasonal and annual timescales, as well as long term averages for a set of climatological reference periods. Variables include air temperature (maximum, minimum and mean), precipitation, sunshine, mean sea level pressure, wind speed, relative humidity, vapour pressure, days of snow lying, and days of ground frost. This data set supersedes the previous versions of this dataset which also superseded UKCP09 gridded observations. Subsequent versions may be released in due course and will follow the version numbering as outlined by Hollis et al. (2018, see linked documentation). This release includes data for the calendar year 2020. Ongoing quality checks and data recovery to historical data results in changes to around 0.01% of the observational station data used as input to produce the gridded dataset. A correction to _FillValue assignment in the metadata for seasonal and annual grids has also been applied to be consistent with the rest of the dataset. The primary purpose of these data are to facilitate monitoring of UK climate and research into climate change, impacts and adaptation. The datasets have been created by the Met Office with financial support from the Department for Business, Energy and Industrial Strategy (BEIS) and Department for Environment, Food and Rural Affairs (DEFRA) in order to support the Public Weather Service Customer Group (PWSCG), the Hadley Centre Climate Programme, and the UK Climate Projections (UKCP18) project. The data recovery activity to supplement 19th and early 20th Century data availability has also been funded by the Natural Environment Research Council (NERC grant ref: NE/L01016X/1) project "Analysis of historic drought and water scarcity in the UK". The dataset is provided under Open Government Licence.

Characterising and Interpreting FLuxes Over Sea Ice (CANDIFLOS) is a data analysis project drawing upon data from multiple field campaigns. It aims to improve the parameterization of surface fluxes over sea ice. This data set consists of the processed surface heat fluxes and sea ice fractions from the Arctic Clouds Summer Experiment (ACSE) project (2014) conducted on icebreaker Oden. Matching data from the AO2016 cruise are provided as a separate data set.