Keyword

CFARR

43 record(s)
 
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  • Measurements from a LI-COR LI-7500 open path gas analyser operating at infra-red wavelengths deployed at the Chilbolton Facility for Atmospheric and Radio Research site in Chilbolton, Hampshire. The instrument measures the absorption due to carbon dioxide at specific wavelengths along its 0.125m measurement path. Internally-stored calibration data are used to convert these absorption values to a mole concentration for each gas. Carbon dioxde and water vapour mole concentrations from this instrument are also provided with sonic anemomenter data at a 20Hz data acquisition rate for eddy covariance calculations in another CFARR dataset. Measurements are taken at 10s intervals and are archived at this temporal resolution. Data are in netCDF.

  • Sky images collected by a JVC KYF55-BE digital camera over Sparsholt College, Hampshire. The data were collected from 5th of July 1996 to end of 1997 before the camera was relocated to the main Chilbolton Observatory, Hampshire. See the linked instrument details record (under the Process information) for subsequent data from this instrument.

  • Sky images collected by a sky camera replacing the earlier JVC KYF55-BE digital camera deployed at the Chilbolton Observatory, Hampshire. These differ from the previous camera imagery by the use of a fish-eye lens to give complete sky imagery. These images have been captured from mid-2016 to the present.

  • 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.

  • Sky images collected by a JVC KYF55-BE digital camera over Chilbolton, Hampshire. The data were collected from 5th of July 1996 to the present.

  • The Chilbolton Facility for Atmopsheric and Radio Research's aerosol particle concentration measurements are provided by a 164DM environmental dust monitor manufactured by Grimm Aerosol Technik. A Lufft WS500 weather station is incorporated into the instrument to provide co-located meteorological measurements. Alternatively, particle mass concentrations can be produced as PM1, PM2.5 and PM10 measurements. The instrument measures the size and number density of aerosol molecules by using a 0.5m vertical inlet to suck ambient air into a measurement chamber. The scattering of a laser beam transmitted through the chamber is used to deduce size and concentration information. It is operated continuously on the roof of a cabin at a height of 8m above ground at the Chilbolton Observatory site. Measurements are taken every 60s, providinga erosol particle concentration (counts/m3) in 31 size bins in the range 0.265-34.0 um, air temperature, relative humidity, air pressure, wind speed and wind direction. The instrument is calibrated every 18 months by the manufacturer

  • The Campbell Scientific PWS100 present weather sensor deployed at the Chilbolton Observatory, Hampshire, detects and classifies precipitation by observing the scattering of a laser beam 20 degrees off the forward direction in the horizontal and vertical planes. The detected signals depend on the size, shape, optical properties, concentration and velocity of the particles. The instrument is mounted approximately 10m above ground on the roof of a cabin at the Chilbolton Observatory site. It is operated continuously. Data include: counts as a function of size of hydrometeors in 300 bins from 0.1 to 30.0 mm, the number of hydrometeors in 9 type categories. visibility, air temperature, relative humidity, rainfall rate, rainfall accumulation, average hydrometeor velocity, average hydrometeor size and reports the World Meteorological Organisation (WMO) present weather code for the site. Data are archived as netCDF files.

  • Data are of sky images collected by an AXIS 2100 digital camera over Chilbolton, Hampshire. The data collected are from 21st of January 2005 to the present and are available in avi movie files and tar files of jpeg images. Images are taken every 15 seconds.

  • 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.

  • Data were collected from the 12th of September 2006 to the 30th of June 2011 by the HALO photonics Doppler lidar at Chilbolton Observatory, Hampshire. The dataset contains measurements attenuated backscatter coefficients of aerosols within the atmosphere, as well as the radial and Doppler velocity of these particles. Plots of the attenuated backscatter coefficient at different heights, and of the Doppler velocity of particles are also available.