ERA5 (European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis) is the fifth generation ECMWF atmospheric reanalysis of the global climate covering the period from January 1940 to present. It is produced by the Copernicus Climate Change Service (C3S) at ECMWF and provides hourly estimates of a large number of atmospheric, land and oceanic climate variables. The data cover the Earth on a 31 kilometer (km) grid and resolve the atmosphere using 137 levels from the surface up to a height of 80 km. ERA5 includes an ensemble component at half the resolution to provide information on synoptic uncertainty of its products. ERA5.1 is a dedicated product with the same horizontal and vertical resolution that was produced for the years 2000 to 2006 inclusive to significantly improve a discontinuity in global-mean temperature in the stratosphere and uppermost troposphere that ERA5 suffers from during that period. Users that are interested in this part of the atmosphere in this era are advised to access ERA5.1 rather than ERA5. ERA5 and ERA5.1 use a state-of-the-art numerical weather prediction model to assimilate a variety of observations, including satellite and ground-based measurements, and produces a comprehensive and consistent view of the Earth's atmosphere. These products are widely used by researchers and practitioners in various fields, including climate science, weather forecasting, energy production and machine learning among others, to understand and analyse past and current weather and climate conditions.

ERA5 is the fifth generation ECMWF reanalysis for the global climate and weather for the past 8 decades. Data is available from 1940 onwards. ERA5 replaces the ERA-Interim reanalysis. Reanalysis combines model data with observations from across the world into a globally complete and consistent dataset using the laws of physics. This principle, called data assimilation, is based on the method used by numerical weather prediction centres, where every so many hours (12 hours at ECMWF) a previous forecast is combined with newly available observations in an optimal way to produce a new best estimate of the state of the atmosphere, called analysis, from which an updated, improved forecast is issued. Reanalysis works in the same way, but at reduced resolution to allow for the provision of a dataset spanning back several decades. Reanalysis does not have the constraint of issuing timely forecasts, so there is more time to collect observations, and when going further back in time, to allow for the ingestion of improved versions of the original observations, which all benefit the quality of the reanalysis product. This catalogue entry provides post-processed ERA5 hourly single-level data aggregated to daily time steps. In addition to the data selection options found on the hourly page, the following options can be selected for the daily statistic calculation:

The daily aggregation statistic (daily mean, daily max, daily min, daily sum*) The sub-daily frequency sampling of the original data (1 hour, 3 hours, 6 hours) The option to shift to any local time zone in UTC (no shift means the statistic is computed from UTC+00:00)

*The daily sum is only available for the accumulated variables (see ERA5 documentation for more details). Users should be aware that the daily aggregation is calculated during the retrieval process and is not part of a permanently archived dataset. For more details on how the daily statistics are calculated, including demonstrative code, please see the documentation. For more details on the hourly data used to calculate the daily statistics, please refer to the ERA5 hourly single-level data catalogue entry and the documentation found therein.

After many years of research and technical preparation, the production of a new ECMWF climate reanalysis to replace ERA-Interim is in progress. ERA5 is the fifth generation of ECMWF atmospheric reanalyses of the global climate, which started with the FGGE reanalyses produced in the 1980s, followed by ERA-15, ERA-40 and most recently ERA-Interim. ERA5 will cover the period January 1950 to near real time. ERA5 is produced using high-resolution forecasts (HRES) at 31 kilometer resolution (one fourth the spatial resolution of the operational model) and a 62 kilometer resolution ten member 4D-Var ensemble of data assimilation (EDA) in CY41r2 of ECMWF's Integrated Forecast System (IFS) with 137 hybrid sigma-pressure (model) levels in the vertical, up to a top level of 0.01 hPa. Atmospheric data on these levels are interpolated to 37 pressure levels (the same levels as in ERA-Interim). Surface or single level data are also available, containing 2D parameters such as precipitation, 2 meter temperature, top of atmosphere radiation and vertical integrals over the entire atmosphere. The IFS is coupled to a soil model, the parameters of which are also designated as surface parameters, and an ocean wave model. Generally, the data is available at an hourly frequency and consists of analyses and short (12 hour) forecasts, initialized twice daily from analyses at 06 and 18 UTC. Most analyses parameters are also available from the forecasts. There are a number of forecast parameters (for example, mean rates and accumulations) that are not available from the analyses. Improvements to ERA5, compared to ERA-Interim, include use of HadISST.2, reprocessed ECMWF climate data records (CDR), and implementation of RTTOV11 radiative transfer. Variational bias corrections have not only been applied to satellite radiances, but also ozone retrievals, aircraft observations, surface pressure, and radiosonde profiles.

ERA5-Land is a reanalysis dataset providing a consistent view of the evolution of land variables over several decades at an enhanced resolution compared to ERA5. ERA5-Land has been produced by replaying the land component of the ECMWF ERA5 climate reanalysis. Reanalysis combines model data with observations from across the world into a globally complete and consistent dataset using the laws of physics. Reanalysis produces data that goes several decades back in time, providing an accurate description of the climate of the past. ERA5-Land uses ERA5 atmospheric variables, such as air temperature and air humidity, as input to control the simulated land fields. This is called the atmospheric forcing. Without the constraint of the atmospheric forcing, the model-based estimates can rapidly deviate from reality. Therefore, while observations are not directly used in the production of ERA5-Land, they have an indirect influence through the atmospheric forcing used to run the simulation. In addition, the input air temperature, air humidity and pressure used to run ERA5-Land are corrected to account for the altitude difference between the grid of the forcing and the higher resolution grid of ERA5-Land. This correction is called 'lapse rate correction'. This catalogue entry provides post-processed ERA5-land hourly data aggregated to daily time steps. Note that the accumulated variables are omitted (e.g. total precipitation, runoff, etc - please refer to table 3 in the ERA5-Land online documentation for a full list of accumulated variables). In addition to the data selection options found on the hourly page, the following options can be selected for the daily statistic calculation:

The daily aggregation statistic (daily mean, daily max, daily min) The sub-daily frequency sampling of the original data (1 hour, 3 hours, 6 hours) The option to shift to any local time zone in UTC (no shift means the statistic is computed from UTC+00:00)

Users should be aware that the daily aggregation is calculated during the retrieval process and is not part of a permanently archived dataset. For more details on how the daily statistics are calculated, including demonstrative code and advice on how to return daily statistics for the accumulated variables, please see the documentation. For more details on the hourly data used to calculate the daily statistics, please refer to the ERA5-land hourly data catalogue entry and the documentation found therein.

Please note: Please use ds633.0 to access RDA maintained ERA-5 data, see ERA5 Reanalysis (0.25 Degree Latitude-Longitude Grid) [https://rda.ucar.edu/datasets/ds633.0], RDA dataset ds633.0. This dataset is no longer being updated, and web access has been removed. After many years of research and technical preparation, the production of a new ECMWF climate reanalysis to replace ERA-Interim is in progress. ERA5 is the fifth generation of ECMWF atmospheric reanalyses of the global climate, which started with the FGGE reanalyses produced in the 1980s, followed by ERA-15, ERA-40 and most recently ERA-Interim. ERA5 will cover the period January 1950 to near real time, though the first segment of data to be released will span the period 2010-2016. ERA5 is produced using high-resolution forecasts (HRES) at 31 kilometer resolution (one fourth the spatial resolution of the operational model) and a 62 kilometer resolution ten member 4D-Var ensemble of data assimilation (EDA) in CY41r2 of ECMWF's Integrated Forecast System (IFS) with 137 hybrid sigma-pressure (model) levels in the vertical, up to a top level of 0.01 hPa. Atmospheric data on these levels are interpolated to 37 pressure levels (the same levels as in ERA-Interim). Surface or single level data are also available, containing 2D parameters such as precipitation, 2 meter temperature, top of atmosphere radiation and vertical integrals over the entire atmosphere. The IFS is coupled to a soil model, the parameters of which are also designated as surface parameters, and an ocean wave model. Generally, the data is available at an hourly frequency and consists of analyses and short (18 hour) forecasts, initialized twice daily from analyses at 06 and 18 UTC. Most analyses parameters are also available from the forecasts. There are a number of forecast parameters, e.g. mean rates and accumulations, that are not available from the analyses. Improvements to ERA5, compared to ERA-Interim, include use of HadISST.2, reprocessed...

The North America Regional Reanalysis (NARR) Project is a reanalysis of historical observations using a 32-km version of the National Centers for Environmental Prediction (NCEP) 1993 operational ETA model and ETA data assimilation system (EDAS). The objective is to create a long-term set of consistent climate data on a regional scale for the North American domain. The domain of analyses includes North and Central America as well as small parts of the United Kingdom, Eastern Asia, South America, and areas of the Pacific and Atlantic Oceans. The period of the reanalyses is from October 1978 to the present and analyses were made 8 times daily (3 hour intervals). Horizontal boundary conditions are derived from the NCEP/DOE Global Reanalysis. Advantages over the widely used NCEP/NCAR Reanalysis (180 km) are its higher spatial and temporal resolutions (32 km grid, 45 vertical layers, every three hours) and better treatment of the land surface. This is achieved through the use of a better land-surface model (Noah LSM), the assimilation of more observational data (precipitation, upper air and surface winds), and through a better representation of the terrain (heights, vegetation, soil type). This data set contains "conventional" atmospheric analyses as well as model-derived fields that contain estimates of subsurface, surface, and radiative properties. This data set is encoded in WMO GRIB format version 1 using the NCEP GRIB table 131. The model used a native, "E-grid" for its calculations, however data were interpolated to a Lambert Conformal Conic projection, also known as NAM 221 AWIPS Grid - High Resolution North American Master Grid (32-km Resolution). All vector components are earth relative rather than grids relative which is the convention for operational NCEP model. The list of fields produced by the NARR ETA model differ from the operational ETA model. NARR data files that are compatible with the Grid Analysis and Display System (GrADS) are available.

Please note: Please use ds633.1 to access RDA maintained ERA-5 Monthly Mean data, see ERA5 Reanalysis (Monthly Mean 0.25 Degree Latitude-Longitude Grid), RDA dataset ds633.1. This dataset is no longer being updated, and web access has been removed. After many years of research and technical preparation, the production of a new ECMWF climate reanalysis to replace ERA-Interim is in progress. ERA5 is the fifth generation of ECMWF atmospheric reanalyses of the global climate, which started with the FGGE reanalyses produced in the 1980s, followed by ERA-15, ERA-40 and most recently ERA-Interim. ERA5 will cover the period January 1950 to near real time, though the first segment of data to be released will span the period 2010-2016. ERA5 is produced using high-resolution forecasts (HRES) at 31 kilometer resolution (one fourth the spatial resolution of the operational model) and a 62 kilometer resolution ten member 4D-Var ensemble of data assimilation (EDA) in CY41r2 of ECMWF's Integrated Forecast System (IFS) with 137 hybrid sigma-pressure (model) levels in the vertical, up to a top level of 0.01 hPa. Atmospheric data on these levels are interpolated to 37 pressure levels (the same levels as in ERA-Interim). Surface or single level data are also available, containing 2D parameters such as precipitation, 2 meter temperature, top of atmosphere radiation and vertical integrals over the entire atmosphere. The IFS is coupled to a soil model, the parameters of which are also designated as surface parameters, and an ocean wave model. Generally, the data is available at an hourly frequency and consists of analyses and short (18 hour) forecasts, initialized twice daily from analyses at 06 and 18 UTC. Most analyses parameters are also available from the forecasts. There are a number of forecast parameters, e.g. mean rates and accumulations, that are not available from the analyses. Together, the hourly analysis and twice daily forecast parameters form the basis of the monthly...

Products from NCEP/NCAR Reanalysis Project (NNRP or R1) are archived in this dataset. The resolution of the global Reanalysis Model is T62 (209 km) with 28 vertical sigma levels. Results are available at 6 hour intervals. Although the initial plan is to reanalyze the data for a 40-year period (1957-1996), production has gone back to 1948 and going forward continuously. Future plans call for rerunning the entire period as next generation models are ready. There are over 80 different variables, (including geopotential height, temperature, relative humidity, u- and v- wind components, etc.) in several different coordinate systems, such as 17 pressure level stack on 2.5 by 2.5 degree grids, 28 sigma level stack on 192 by 94 Gaussian grids, and 11 isentropic level stack on 2.5 by 2.5 degree grid. They are organized as different subgroups in the archive. In addition to analyses, diagnostic terms (for example: radiative heating, convective heating) and accumulative variables (like precipitation rate) are present. The input observations are archived with quality and usage flags in WMO BUFR format. Most of the project outputs are stored in WMO GRIB format. Other files, such as restart files and zonal statistics, are saved in IEEE format. Some special periods are analyzed more than once to provide data for special research studies. For example, a special run of 1979 was made excluding most satellite inputs. This run could be used for evaluating the impact of satellite data on the analysis. During the TOGA COARE experiment period, special runs of reanalysis model without experimental data are archived under the TOGA COARE directory. For details and problems, see NCEP/NCAR Reanalysis TOGA COARE [https://rda.ucar.edu/datasets/ds090.0/inventories/TOGA-COARE/]. Monthly means are on line at ds090.2 [https://rda.ucar.edu/datasets/ds090.2/]. The R1 forecasts are in ds090.1 [https://rda.ucar.edu/datasets/ds090.1/] dataset.

This repo contains converted ECMWF ERA5 reanalysis files for both hourly atmospheric and land variables from Jan 2014 to October 2022. The data has been converted from the downloaded NetCDF files into Zarr using Xarray. Each file is 1 day of reanalysis, and so has 24 timesteps at a 0.25 degree grid resolution. All variables in the reanalysis are included here.

Climate reanalysis is a systematic approach used to produce meteorological datasets for climate monitoring and research. They are created using a fixed version of a forecast model and a data assimilation system which utilises historical observations and they produce parameters that are physically consistent and often not routinely observed. Thus, climate reanalyses have the potential to extend the knowledge gained from current observation networks. Met Éireann has carried out a 35-year very high resolution (2.5 km horizontal grid) regional climate reanalysis for Ireland using the ALADIN-HIRLAM numerical weather prediction system (www.hirlam.org). This reanalysis spans the period 1981 to 2015 and includes surface, near-surface and atmospheric parameters and is the first of its kind for Ireland.

This dataset contains ERA5 model level analysis parameter data. ERA5 is the 5th generation reanalysis project from the European Centre for Medium-Range Weather Forecasts (ECWMF) - see linked documentation for further details. This dataset contains a limited selection of all available variables and have been converted to netCDF from the original GRIB files held on the ECMWF system. They have also been translated onto a regular latitude-longitude grid during the extraction process from the ECMWF holdings. For a fuller set of variables please see the linked Copernicus Data Store (CDS) data tool, linked to from this record.

Surface level analysis and forecast data to complement this dataset are also available. Data from a 10 member ensemble, run at lower spatial and temporal resolution, were also produced to provide an uncertainty estimate for the output from the single high resolution (hourly output at 31 km grid spacing) 'HRES' realisation producing data in this dataset.

The ERA5 global atmospheric reanalysis of the covers 1979 to 2 months behind the present month. This follows on from the ERA-15, ERA-40 rand ERA-interim re-analysis projects.

An initial release of ERA5 data (ERA5t) is made roughly 5 days behind the present date. These will be subsequently reviewed ahead of being released by ECMWF as quality assured data within 3 months. CEDA holds a 6 month rolling copy of the latest ERA5t data. See related datasets linked to from this record. However, for the period 2000-2006 the initial ERA5 release was found to suffer from stratospheric temperature biases and so new runs to address this issue were performed resulting in the ERA5.1 release (see linked datasets). Note, though, that Simmons et al. 2020 (technical memo 859) report that "ERA5.1 is very close to ERA5 in the lower and middle troposphere." but users of data from this period should read the technical memo 859 for further details.

Overview: ERA5-Land is a reanalysis dataset providing a consistent view of the evolution of land variables over several decades at an enhanced resolution compared to ERA5. ERA5-Land has been produced by replaying the land component of the ECMWF ERA5 climate reanalysis. Reanalysis combines model data with observations from across the world into a globally complete and consistent dataset using the laws of physics. Reanalysis produces data that goes several decades back in time, providing an accurate description of the climate of the past. Total precipitation: Accumulated liquid and frozen water, including rain and snow, that falls to the Earth's surface. It is the sum of large-scale precipitation (that precipitation which is generated by large-scale weather patterns, such as troughs and cold fronts) and convective precipitation (generated by convection which occurs when air at lower levels in the atmosphere is warmer and less dense than the air above, so it rises). Precipitation variables do not include fog, dew or the precipitation that evaporates in the atmosphere before it lands at the surface of the Earth. This variable is accumulated from the beginning of the forecast time to the end of the forecast step. The units of precipitation are depth in metres. It is the depth the water would have if it were spread evenly over the grid box. Care should be taken when comparing model variables with observations, because observations are often local to a particular point in space and time, rather than representing averages over a model grid box and model time step. The original ERA5-Land dataset (period: 2000 - 2020) has been reprocessed to: - aggregate ERA5-Land hourly data to daily data (minimum, mean, maximum) - while increasing the resolution from the native ERA5-Land resolution of 0.1 degree (~ 9 km) to 30 arc-sec (~ 1 km) by image fusion with CHELSA data (V1.2) (https://chelsa-climate.org/). For each day we used the corresponding monthly long-term average of CHELSA. The aim was to use the fine spatial detail of CHELSA and at the same time preserve the general regional pattern and fine temporal detail of ERA5-Land. The steps included aggregation and enhancement, specifically: 1. spatially aggregate CHELSA to the resolution of ERA5-Land 2. calculate proportion of ERA5-Land / aggregated CHELSA 3. interpolate proportion with a Gaussian filter to 30 arc seconds 4. multiply the interpolated proportions with CHELSA Using proportions ensures that areas without precipitation remain areas without precipitation. Only if there was actual precipitation in a given area, precipitation was redistributed according to the spatial detail of CHELSA. Data available is the daily sum of precipitation. Software used: GDAL 3.2.2 and GRASS GIS 8.0.0 (r.resamp.stats -w; r.relief) Original ERA5-Land dataset license: https://cds.climate.copernicus.eu/api/v2/terms/static/licence-to-use-copernicus-products.pdf CHELSA climatologies (V1.2): Data used: Karger D.N., Conrad, O., Böhner, J., Kawohl, T., Kreft, H., Soria-Auza, R.W., Zimmermann, N.E, Linder, H.P., Kessler, M. (2018): Data from: Climatologies at high resolution for the earth's land surface areas. Dryad digital repository. http://dx.doi.org/doi:10.5061/dryad.kd1d4 Original peer-reviewed publication: Karger, D.N., Conrad, O., Böhner, J., Kawohl, T., Kreft, H., Soria-Auza, R.W., Zimmermann, N.E., Linder, P., Kessler, M. (2017): Climatologies at high resolution for the Earth land surface areas. Scientific Data. 4 170122. https://doi.org/10.1038/sdata.2017.122

The 20th Century Reanalysis dataset provides 6 hourly analyses on a Global 2.0 degree latitude x 2.0 degree longitude global grid from 1871 to present produced from a series of 56-member ensemble runs. For each output time step ensemble means and associated spreads have been calculated and form a continuous dataset over the entire timespan of the dataset. The data contain fields at the surface and on pressure levels from 1000 hPa to 10 hPa. The dataset authors request that the following acknowledgment be included in all papers using the dataset: 'Support for the Twentieth Century Reanalysis Project dataset is provided by the U.S. Department of Energy, Office of Science Innovative and Novel Computational Impact on Theory and Experiment (DOE INCITE - http://www.doeleadershipcomputing.org/incite-program/ ) program, and Office of Biological and Environmental Research (BER - http://science.energy.gov/ber/ ), and by the National Oceanic and Atmospheric Administration Climate Program Office (http://www.climate.noaa.gov/).'

NOAA's Coastal Ocean Reanalysis (CORA) for the Gulf, East Coast/Atlantic, and Caribbean (GEC) is produced using verified hourly water levels from the National Ocean Service’s Center of Operational Oceanographic Products & Services (CO-OPS). ADvanced CIRCulation Model (ADCIRC) and Simulating WAves Nearshore (SWAN) models are coupled to model coastal water levels and nearshore waves. Hourly water level observations are used for data assimilation and validation to improve the accuracy of modeled water levels and wave datasets.

Additional Details:
Metadata associated with model domain and time span:

• Timeseries - 1979 to 2022
• Size - Approx. 44.6 TB
• Domain - Lat 5.8 to 45.8 ; Long -98.0 to -53.8
• Nodes - CORA Metadata Library
• Grid cells - CORA Metadata Library
• Spatial Resolution:
  • Centroids: 300-400 meters
  • Gridded: 500 meters
  • Projection: 1983 Contiguous USA Albers projection (EPSG:5070)
    
    

• fort.63.nc - Water level elevation
• fort.73.nc - Atmospheric pressure at sea level
• fort.74.nc - Wind Velocity - 10 m elevation
• maxele.63.nc - Maximum water elevation
• swan_DIR.63.nc - Spectral mean wave direction
• swan_TMM10.63.nc - Spectral mean wave period
• swan_TPS.63.nc - Spectral peak wave period
• swan_HS.63.nc - Spectral zeroth moment wave height
• swan_HS_max.63.nc - Maximum spectral zeroth moment wave height
  
  

• CORA-V1.1-fort.63: Hourly water levels
• CORA-V1.1-swan_DIR.63: Hourly mean wave direction
• CORA-V1.1-swan_TPS.63: Hourly peak wave periods
• CORA-V1.1-swan_HS.63: Hourly significant wave heights
• CORA-V1.1-Grid: Hourly water levels interpolated from model nodes to uniform 500-meter resolution grid
  
  

This data set for the ISLSCP Initiative II data collection provides near surface meteorological variables, fluxes of heat, moisture and momentum at the surface, and land surface state variables, all with a spatial resolution of 1 degree in both latitude and longitude. There are four temporal categories of data: time invariant and monthly mean annual cycle fields (together referred to as "fixed" fields), monthly mean fields, monthly 3-hourly diurnal, and 3-hourly fields. Two types of variables exist in this data; instantaneous fields (primarily state variables), and average fields (primarily flux fields expressed as a rate). The Center for Ocean-Land Atmosphere Studies (COLA) near-surface data set for ISLSCP II was derived from the National Centers for Environmental Prediction (NCEP)/Department of Energy (DOE) Atmospheric Model Inter-comparison Project (AMIP-II) reanalysis (http://www.cpc.ncep.noaa.gov/products/wesley/reanalysis2/), covering the years from 1979-2003. The data set for ISLSCP II covers the period from 1986 to 1995. The purpose of the reanalysis was to provide an improved version of the original NCEP/National Center for Atmospheric Research (NCAR) reanalysis for General Circulation Model (GCM) validation. To co-register the NCEP/DOE reanalysis on the ISLSCP 1-degree grid, the reanalysis data set was regridded from its native T62 Gaussian grid) resolution (192 x 94 grid boxes globally) to 1-degree ISLSCP II required resolution.There are 136 compressed (.tar.gz) data files with this data set. When extrapolated, the individual data files are in ASCII (.asc) format.

The 20th Century Reanalysis dataset provides 6 hourly analyses on a global grid from 1870 to present produced from a series of 56-member ensemble runs. These data are the from each of the 56 ensemble members from the run covering 1881 to 1885. These data were produced on a 2 degree latitude-longitude (180x91) global grid and include data both at the surface and on pressure levels.

The dataset authors request that the following acknowledgment be included in all papers using the dataset:

'Support for the Twentieth Century Reanalysis Project dataset is provided by the U.S. Department of Energy, Office of Science Innovative and Novel Computational Impact on Theory and Experiment (DOE INCITE - http://www.doeleadershipcomputing.org/incite-program/ ) program, and Office of Biological and Environmental Research (BER - http://science.energy.gov/ber/ ), and by the National Oceanic and Atmospheric Administration Climate Program Office (http://www.climate.noaa.gov/).'

The CRU JRA V2.5 dataset is a 6-hourly, land surface, gridded time series of ten meteorological variables produced by the Climatic Research Unit (CRU) at the University of East Anglia (UEA), and is intended to be used to drive models. The variables are provided on a 0.5 degree latitude x 0.5 degree longitude grid, the grid is near global but excludes Antarctica (this is the same as the CRU TS grid, though the set of variables is different). The data are available at a 6 hourly time-step from January 1901 to December 2023.

The dataset is constructed by regridding data from the Japanese Reanalysis data (JRA) produced by the Japanese Meteorological Agency (JMA), adjusting where possible to align with the CRU TS 4.08 data (see the Process section and the ReadMe file for full details).

The CRU JRA data consists of the following ten meteorological variables: 2-metre temperature, 2-metre maximum and minimum temperature, total precipitation, specific humidity, downward solar radiation flux, downward long wave radiation flux, pressure and the zonal and meridional components of wind speed (see the ReadMe file for further details).

The CRU JRA dataset is intended to be a replacement of the CRU NCEP forcing dataset. The CRU JRA dataset follows the style of Nicolas Viovy's original CRU NCEP dataset rather than that which is available from UCAR. A link to the CRU NCEP documentation for comparison is provided in the documentation section. This version of CRUJRA, v2.5 (1901-2023) is, where possible, adjusted to align with CRU TS monthly means or totals. A consequence of this is that, if CRU TS changes, then CRUJRA changes.

For this version, and version 4.07 of CRU TS, the CLD (cloud cover, %) variable is now actualised (converted from gridded anomalies) using the original CLD climatology and not the revised climatology introduced last year. This change/reversion is summarised here: https://crudata.uea.ac.uk/cru/data/hrg/cru_cl_1.1/Read_Me_CRU_CL_CLD_Reversion.txt

Since CLD is used to align DSWRF, CRUJRA Downward Short Wave Radiation Flux (DSWRF) will now be 'closer to' version 2.2 and earlier and should be used in preference to v2.3.

If this dataset is used in addition to citing the dataset as per the data citation string users must also cite the following:

Harris, I., Osborn, T.J., Jones, P. et al. Version 4 of the CRU TS monthly high-resolution gridded multivariate climate dataset. Sci Data 7, 109 (2020). https://doi.org/10.1038/s41597-020-0453-3

Harris, I., Jones, P.D., Osborn, T.J. and Lister, D.H. (2014), Updated high-resolution grids of monthly climatic observations - the CRU TS3.10 Dataset. International Journal of Climatology 34, 623-642.

Kobayashi, S., et. al., The JRA-55 Reanalysis: General Specifications and Basic Characteristics. J. Met. Soc. Jap., 93(1), 5-48 https://dx.doi.org/10.2151/jmsj.2015-001

This dataset provides a regional multivariate oceanographic state estimate from a global ocean numerical simulation with a focus on the Baltic Sea region. The global ocean simulation is based on the MIT general circulation model (MITgcm) with Lat-Lon-Cap grid (LLC) layout and 1/48-degree (2km at equator) nominal horizontal resolution. This simulation is often referred to as LLC4320 in the community and existing publications. The simulation has 90 vertical levels, with about 1-m vertical resolution at the surface and 30 m down to 500 m, for optimized resolution of the upper-ocean processes. The model has zero parameterized horizontal diffusivity. In the vertical direction, the K-Profile Parameterization (KPP) is used for boundary layer turbulent mixing. It is spun up progressively from the lower resolution MITgcm simulation from the Estimating the Circulation & Climate of the Ocean (ECCO), and forced by the 6-hourly ERA-Interim atmosphere reanalysis ( https://www.ecmwf.int/en/forecasts/datasets/reanalysis-datasets/era-interim ). A synthetic surface pressure field consisting of the 16 most dominant tidal constituents is used to dynamically mimic the tidal forcing. The dataset provides hourly oceanographic variables at native grid. Three-dimensional variables include temperature, salinity, and velocity. Two-dimensional variables include sea level anomaly, ocean mixed layer thickness, bottom pressure anomaly, net freshwater flux, net heat flux, shortwave radiative flux, net salt flux, and ocean surface stress.

This metadata record serves as documentation for the authoritative version of the CONUS404 atmospheric forcing dataset. CONUS404 is an abbreviated description for the original 40-year dataset: CONtiguous United States for 40 years at 4-kilometer grid spacing; however, the dataset has been revised to now include 43 years of data. This is a dataset of historical conditions (water years 1980-2022, October 1, 1979-September 30, 2022) and has sufficient temporal and spatial detail to resolve mesoscale atmospheric processes, making it appropriate for forcing hydrological models and conducting meteorological analyses. The dataset is the output of the Weather Research and Forecasting (WRF) v 3.9.1.1 model (Skamarock and others, 2008), forced with ERA5 reanalysis data (Hersbach and others, 2020), and consists of time series of nearly 200 2-dimensional variables and a wide range of 3-dimensional variables. Three sets of files were produced at different temporal resolutions: (1) 376,944 hourly files with all model outputs (files contained in wrfout directory), (2) 15,706 daily files containing data at 15-minute increments for precipitation and 2-meter temperature (files contained in auxhist24 directory), and (3) 15,706 daily files with minimum, maximum, and average values of a selection of surface variables (files contained in wrfxtrm directory). The Entity and Attribute element of the metadata record documents data dictionaries for all the variables in each of the three types of output files. These data dictionaries are attached to this data release. The output files are approximately one petabyte (1 PB) in volume and are being archived on the U.S. Geological Survey's Black Pearl tape drive system. The data can be accessed through a Globus access portal here: https://app.globus.org/file-manager?origin_id=12aeed7a-9693-4f99-9816-96911c1322d2&origin_path=%2F&two_pane=true. Please refer to the Supplemental Information element of this metadata record for further information on CONUS404.

The 20th Century Reanalysis dataset provides 6 hourly analyses on a global grid from 1870 to present produced from a series of 56-member ensemble runs. These data are the from each of the 56 ensemble members from the run covering 1886 to 1890. These data were produced on a 2 degree latitude-longitude (180x91) global grid and include data both at the surface and on pressure levels. The dataset authors request that the following acknowledgment be included in all papers using the dataset: 'Support for the Twentieth Century Reanalysis Project dataset is provided by the U.S. Department of Energy, Office of Science Innovative and Novel Computational Impact on Theory and Experiment (DOE INCITE - http://www.doeleadershipcomputing.org/incite-program/ ) program, and Office of Biological and Environmental Research (BER - http://science.energy.gov/ber/ ), and by the National Oceanic and Atmospheric Administration Climate Program Office (http://www.climate.noaa.gov/).'