The NERC-funded Microphysics of Antarctic Clouds (MAC) project was centred on an aircraft campaign measuring clouds, aerosols, and boundary layer properties over the Weddell Sea, Antarctica. These data are simulations of the Polar-optimised Weather Research and Forecasting (PWRF) model for 5 configurations of the model's Morrison microphysics scheme, produced for a case study of two separate flights over the same region during the campaign (British Antarctic Survey MASIN twin-otter aircraft flights 218 an 219 on 27th November 2015). Each simulation contains data from two domains - a parent domain with 5km grid size and a nest with a 1km grid size. The control simulation used default physics options in the PWRF model's Morrison microphysics scheme. For the no-threshold, 2xHM, 5xHM, 10xHM simulations, thresholds restricting Hallett-Mossop secondary ice production in the PWRF model's Morrison microphysics scheme were removed, and for the 2xHM, 5xHM, and 10xHM cases the corresponding ice multiplication factor was increased by a factor of 2, 5 or 10. In all simulations, an approximation of the DeMott et al., 2010 (PNAS) parametrization used for primary ice nucleation. Methodology and further details can be found in Young et al., 2019 (Geophysical Research Letters): Radiative effects of secondary ice enhancement in coastal Antarctic clouds.

This dataset contains all the UM-GA8.0 climate model output needed to reproduce Table 2 and Figures 7-10 in the paper Below-cloud scavenging of aerosol by rain: A review of numerical modelling approaches and sensitivity simulations with mineral dust by Anthony C. Jones, Adrian Hill, John Hemmings, Pascal Lemaitre, Arnaud Querel, Claire L. Ryder, and Stephanie Woodward, Submitted to Atmospheric Chemistry and Physics, May 2022, as well as Figures S7-S13 in the Supplementary material. UM-GA8.0 is the Met Office Unified Model General Atmosphere vn8.0 in a climate configuration (N96L85) and using AMIP protocol (see Jones et al., 2022 for more details). All files are CF-1.7 compliant and in NetCDF format with appropriate metadata. Each file contains monthly mean data for the 15 simulated years used in the paper (the 5 year spin up is not provided). The files are separated into folders by experiment name: Folder | Simulation name (Table 1 in Jones et al., 2022) ------------------------------------------------------------- Slinn | Slinn Slinnph | Slinn+ph Slinnphrc | Slinn+ph+rc Wang | Wang Laakso | Laakso SlinnPhRc1M | Slinn+ph+rc(1M) SlinnPhRcDm | Slinn+ph+rc(dm) LaaksoDm | Laakso(dm) The files use standard CMIP naming conventions with one slight modification: before the 'nc' suffix, the aerosol mode that the variable applies to is generally given (either coarse (cor) or accumulation (acc) mode). The STARTDATE and ENDDATES are the same for all files (12/1993 and 11/2008 respectively). As is the TIMEPERIOD (Amon, i.e., monthly mean data) and the MODEL (MetUM, else known as UM-GA8.0). VARIABLE_TIMEPERIOD_MODEL_EXPERIMENT_STARTDATE_ENDDATE.MODE.nc The variables comprise: Short name | Description (units, if any) ------------------------------------------------------------- conccn | Particle number concentration (m-3) concdust | Particle mass concentration (kg.m-3) diamdust | Modal median diameter (m) drydust | Dust dry deposition rate (kg.m-2.s-1) emidust | Dust surface emission rate (kg.m-2.s-1) loaddust | Vertically integrated dust load (kg.m-2) mmratedust | Dust mode-merging (cor->acc) rate (kg.m-3.s-1) od443dust | Dust optical depth at 443 nm od550dust | Dust optical depth at 443 nm orog | Surface Altitude (m) wetdust | Dust wet deposition rate (kg.m-2.s-1) zfull | Model altitude at the top of the gridcell (m) The mass concentration (concdust), number concentration (conccn), and mass burden (loaddust) were calculated from monthly-mean mass or number mixing ratios and monthly mean potential temperature, pressure, and specific humidity fields (not supplied). The mode mixing rate (mmratedust) is only available for the downard mode merging simulations (SlinnPhRcDm and LaaksoDm). All figures in the paper were produced using Python (3.6) and Iris scientific analysis software. All data is Crown Copyright, Met Office, and is made available under the terms of the Non-Commercial Government Licence: http://www.nationalarchives.gov.uk/doc/non-commercial-government-licence/version/2/

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 datasets cover the UK at 1 km x 1 km resolution. These 1 km x 1 km data have been used to provide a range of other resolutions and across countries, administrative regions and river basins to allow for comparison to 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.

This dataset contains monthly mean ozone output between 1979-2016 simulated by the TOMCAT/SLIMCAT model. The data contains ozone and a passive odd-oxygen tracer that is set equal to the modelled chemical Ox =O(3 P)+O(1 D)+ O3 concentration on the first day every year and then advected passively without chemistry. It was simulated using the TOMCAT/SLIMCAT three-dimensional offline chemical transport model, using σ-p vertical coordinates and identical stratospheric chemistry and aerosol loading, solar flux input and surface mixing ratios of long-lived source gases. The long-term simulation (1979-2016) was performed with a T42 horizontal resolution of approximately 2.8° latitude × 2.8° longitude and 32 levels from the surface to 60 km. The model uses horizontal winds and temperature from the reanalysis data of the European Centre for Medium-Range Weather Forecasts. The TOMCAT/SLIMCAT model contains a detailed description of the distribution of chemical species for the troposphere and stratosphere including heterogeneous reactions on sulfate aerosols and liquid/solid polar stratospheric clouds either with a simple or full microphysical PSC scheme, as well as chemistry reactions of the oxygen, nitrogen, hydrogen, chlorine and bromine families. The model uses a hybrid σ-p or σ-θ vertical coordinate and has an option to run at different horizontal resolution forced by different meteorological reanalysis. Tracer transport uses the conservation of the second order moments scheme of Prather. Vertical advection is calculated from the divergence of the horizontal mass flux.

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.

Starting in February 2017, a network of 14 Thies™ manufactured Laser Precipitation Monitors (LPMs) were installed at various locations around the United Kingdom to create the Disdrometer Verification Network (DiVeN). The instruments were installed for verification of radar hydrometeor classification algorithms but are valuable for much wider use in the scientific and operational meteorological community. Every Thies LPM is able to designate each observed hydrometeor into one of 20 diameter bins from >= 0.125 mm to > 8 mm, and one of 22 speed bins from > 0.0 m s-1 to > 20.0 m s-1. A laser and diode receiver operate in tandem; a falling particle will occlude the beam. The duration of the occlusion and the maximum extent (measured by diode voltage) determines the fall velocity and diameter respectively. Using empirically-derived relationships, the instrument classifies precipitation into one of 11 possible hydrometeor classes in the form of a 'present weather code', with an associated indicator of uncertainty. To provide immediate feedback to data users, the observations are plotted in near real time (NRT) and made publicly available on a website within 7 minutes (see linked documentation section). A 'present weather code' is a World Meteorological Organisation (WMO) code used to define the present observatory weather (see linked documentation for the WMO present weather code list). The instruments belonged to the Met Office but were loaned to the National Centre for Atmospheric Science (NCAS) for the duration of the project. NCAS handle the receiving server for real-time DiVeN data, which is the only route to this dataset. On-site collection of data are not guaranteed in all circumstances. Some of the sites rely on unreliable O2 3G dongles; whilst the Feshie instrument was solar and wind powered and the Coverhead instrument suffered from power / connectivity issues. Any missing data can be explained by these reasons, and are handled appropriately in the files. The data were collated into daily files of 1440 minutes. More information can be found in Pickering et al., 2018, see related documentation.

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

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 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. Additionally, this version has corrected the grid definition used for the 12 km grid product to match UKCP18 climate model products. 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.

Radio propagation measurements at 40 GHz at Chilton, Oxfordshire for the ESA funded Large Scale Assessment of KA/Q band atmospheric channel using the ALPHASAT TDP5 Propagation beacon signal.

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/