Data were collected by the Chilbolton Facility for Atmospheric and Radio Research (CFARR) Infra-Red Radiometer from 10th of May 2001 to the present at Chilbolton, Hampshire. The dataset contains measurements for both sky and surface emitted infrared radiation, from 4.5 to 42 µm.

This dataset contains ERA5 surface level analysis parameter data ensemble means (see linked dataset for spreads). ERA5 is the 5th generation reanalysis project from the European Centre for Medium-Range Weather Forecasts (ECWMF) - see linked documentation for further details. The ensemble means and spreads are calculated from the ERA5 10 member ensemble, run at a reduced resolution compared with the single high resolution (hourly output at 31 km grid spacing) 'HRES' realisation, for which these data have been produced to provide an uncertainty estimate. 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. Note, ensemble standard deviation is often referred to as ensemble spread and is calculated as the standard deviation of the 10-members in the ensemble (i.e., including the control). It is not the sample standard deviation, and thus were calculated by dividing by 10 rather than 9 (N-1). See linked datasets for ensemble member and ensemble mean data. 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.

This dataset contains ERA5 surface level analysis parameter data from 10 ensemble runs. ERA5 is the 5th generation reanalysis project from the European Centre for Medium-Range Weather Forecasts (ECWMF) - see linked documentation for further details. The ensemble members were used to derive means and spread data (see linked datasets). Ensemble means and spreads were calculated from the ERA5t 10 member ensemble, run at a reduced resolution compared with the single high resolution (hourly output at 31 km grid spacing) 'HRES' realisation, for which these data have been produced to provide an uncertainty estimate. 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. Note, ensemble standard deviation is often referred to as ensemble spread and is calculated as the standard deviation of the 10-members in the ensemble (i.e., including the control). It is not the sample standard deviation, and thus were calculated by dividing by 10 rather than 9 (N-1). See linked datasets for ensemble member and ensemble mean data. 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.

A sonic anemometer and a gas analyser measuring water vapour and carbon dioxide are co-located within a compound dedicated to measuring fluxes using the eddy covariance method at Chilbolton Observatory. The eddy covariance technique is an atmospheric measurement method used to calculate vertical turbulent fluxes within the atmospheric boundary layer. This is the lowest region of the troposphere and is usually well mixed, particularly during daylight hours, due to convective heating from the sun. It is this motion in the lower troposphere that makes the technique possible. In order to properly measure the turbulent properties of the atmosphere the measurements must be made at a high frequency - 20 Hz for the Chilbolton Observatory system. A sonic anemometer measures the 3 orthogonal components of the wind velocity by measuring the changes in the time of flight of sonic pulses between 3 transmitter/receiver pairs as a result of the air velocity. A gas analyser measures the absorptance of radiation along a fixed path and uses this to determine the concentration of a gas in air. For each gas the absorptance at 2 wavelengths is measured 152 times per second, one affected by that gas and the other unaffected. There are more accurate instruments available for measuring water vapour and carbon dioxide (e.g. a relative humidity sensor for water vapour) but the benefit of the gas analyser is that it has a sufficiently fast response to resolve the rapid changes in concentration as a result of turbulence.

The UK mean wind data describes the mean wind speed and direction, and the direction, speed and time of the maximum gust, all during 1 or more hours, ending at the stated time and date. The data is collected by observation stations across the UK and transmitted within the following message types: SYNOP, HCM, AWSHRLY, DLY3208, HWNDAUTO and HWND6910. The data spans from 1949 to present.

The global marine meteorological observations data contains marine meteorological values, such as wave heights and periods, wind speed and direction, present weather, and air and sea temperature, measured during the hour ending at the stated date and time. The data is collected by worldwide observation stations and transmitted within the following message types: Ship SYNOP, which is also referred to as FM 13-IX SHIP, FM 18-X BUOY, Light Vessel, Marid, Marine logbooks, NAVY, OWS, PLAT/RIG, and VOF. In this dataset the different message types are all described by the SHIP message name. Data are available from 1854 to present. The data consist of: Offshore wind (speed and direction) Weather (present, past) Cloud (amount, type, base amount, base height) Pressure (mean sea level) Visibility Temperature (air, dew-point, wetbulb, sea) Relative humidity Wave (direction, period, height) Wind-wave (period, height) Swell (direction, -wave period, height) Ship direction and distance Maximum gust speed and period The wind speed is given to the nearest knot, direction to the nearest 10 degrees, and the time of the maximum gust is given to the nearest 0.1 hour. The wind direction from which the wind blows, is measured in Degrees (true). The entry for an east wind is 090, for a south wind it is 180 and so on clockwise. Note that zero values in both wind speed and wind direction fields indicate that there was no wind blowing at the time of observation. The temperature and dew point are given to the nearest 0.1 degree Celsius, the pressure is given to the nearest 0.1 hectopascal, the cloud base height and the visibility are given to the nearest decametre. Cloud amount is reported in oktas. The past weather is recorded as a number between 0-9 which details what the weather has been like in the last 6 hours for observations at 00, 06, 12, 1800 UTC, the last 3 hours for observations at 03, 09, 15, 2100 UTC and the previous hour at any other times. The past weather is only recorded when a manual observation is done at the station. Marine reports are defined by position (latitude and longitude) and by time. Duplicates can exist at a specified position and time, e.g. when ships are alongside for bunkering, so the identifier of the ship or buoy is part of the primary key of the entity. A great many ships do not include a valid call sign in their reports; the call sign may be missing or invalid. When this occurs, Midas will substitute the call sign value “SHIP”.

Atmospheric temperature observations from the Armagh Observatory, founded in 1790 by Archbishop Richard Robinson. As well as astronomical observations various meteorological parameters have been recorded since 1794. If users wish to find data from other areas of work undertaken by the observatory they should visit the Armagh Observatory website. This dataset contains monthly measurements and summaries of air temperature, air pressure, rainfall, wind speed, wind direction, total cloud and hours of sunshine from an automatic weather station.

The UK hourly weather observation data contain meteorological values measured on an hourly time scale. The measurements of the concrete state, wind speed and direction, cloud type and amount, visibility, and temperature were recorded by observation stations across the UK and transmitted within SYNOP, METAR, DLY3208, AWSHRLY and NCM messages. The sunshine duration measurements were transmitted in the HSUN3445 message. The data spans from 1875 to present. This dataset also contains data from a selection of overseas sites: SRC_ID STATION STATUS LAST DATA 1580 GUTERSLOH CLOSED 28/10/2013 13:00 1582 BRUGGEN CLOSED 29/09/2001 05:00 1584 LAARBRUCH CLOSED 14/05/1999 23:00 1585 GIBRALTAR, NORTH FRONT OPEN 03/02/2020 09:00 1588 AKROTIRI, CYPRUS OPEN 03/02/2020 09:00 1603 ASCENSION ISLAND AIRFIELD OPEN 02/02/2020 21:00 1605 BOTTOMS WOOD, ST HELENA OPEN 03/02/2020 09:00 1608 PORT STANLEY, FALKLAND IS CLOSED 31/12/1980 23:00 1609 MOUNT PLEASANT, FALKLAND IS OPEN 03/02/2020 09:00 56810 MOUNT OLYMPUS OPEN 16/04/2019 09:00 61737 MOUNT KENT, FALKLAND ISLANDS OPEN 03/02/2020 09:00 61743 MOUNT BYRON, FALKLAND ISLANDS OPEN 03/02/2020 09:00 61744 MOUNT ALICE, FALKLAND ISLANDS OPEN 02/02/2020 05:00

Continuous measurements are made using a Kipp & Zonen CNR4 net flux radiometer. It measures both downwelling and upwelling radiation in 2 wavelength bands which are common to many similar instruments. A shorter wavelength band measures radiation received from the sun. It encompasses the visible spectrum, together with near infrared and longer wavelength ultraviolet, over a wavelength range of approximately 0.29 - 2.8 µm. It shows a clear response to the day/night cycle. Clouds and other aerosols reduce the detected radiation. A longer wavelength band measures longer wavelength infrared radiation (approximately 4.5 - 32 µm) produced by emission from the atmosphere and earth's surface. It does not respond significantly to the day/night cycle but changes according to the time of year and degree of cloud cover.

Data from the British Geological Survey's GeoIndex Geophysics theme are made available for viewing here. GeoIndex is a website that allows users to search for information about BGS data collections covering the UK and other areas world wide. Access is free, the interface is easy to use, and it has been developed to enable users to check coverage of different types of data and find out some background information about the data. More detailed information can be obtained by further enquiry via the web site: www.bgs.ac.uk/geoindex.