3713e45f434e4e0bb5db6098dfba16e1 English 8-bit variable size UCS Transfer Format, based on ISO/IEC 10646 7cbc3fc19bfa037a48ba4cba4b93544d dataset NCAS British Atmospheric Data Centre (NCAS BADC) +44(0)1235 446432 British Atmospheric Data Centre STFC Rutherford Appleton Laboratory Harwell Oxford OX11 0QX UK badc@rl.ac.uk pointOfContact 2026-05-10T02:05:50 UK GEMINI 2.3 WGS 84 Chilbolton Facility for Atmospheric and Radio Research (CFARR): Gas analyser and Sonic anemometer data 2009-07-29T11:00:00 publication 2009-07-29T11:00:00 creation https://catalogue.ceda.ac.uk/uuid/3713e45f434e4e0bb5db6098dfba16e1 3713e45f434e4e0bb5db6098dfba16e1 NCAS British Atmospheric Data Centre (NCAS BADC) 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. Agnew, Judith Unavailable author Unavailable author NCAS British Atmospheric Data Centre (NCAS BADC) custodian +44(0)1235 446432 British Atmospheric Data Centre STFC Rutherford Appleton Laboratory Harwell Oxford OX11 0QX UK badc@rl.ac.uk custodian NCAS British Atmospheric Data Centre (NCAS BADC) distributor +44(0)1235 446432 British Atmospheric Data Centre STFC Rutherford Appleton Laboratory Harwell Oxford OX11 0QX UK badc@rl.ac.uk distributor Walden, Chris J. Unavailable principal_investigator Unavailable principalInvestigator NCAS British Atmospheric Data Centre (NCAS BADC) point_of_contact +44(0)1235 446432 British Atmospheric Data Centre STFC Rutherford Appleton Laboratory Harwell Oxford OX11 0QX UK badc@rl.ac.uk pointofContact NCAS British Atmospheric Data Centre (NCAS BADC) publisher +44(0)1235 446432 British Atmospheric Data Centre STFC Rutherford Appleton Laboratory Harwell Oxford OX11 0QX UK badc@rl.ac.uk publisher monthly dataset CFARR gas analyser anenometer atmospheric conditions theme GEMET - INSPIRE themes, version 1.0 2008-06-01 publication otherRestrictions Access to these data is available to any registered CEDA user. Please Login or Register for a CEDA account to gain access. otherRestrictions Under the following licence http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/, appropriate use of these data may fall under any use. This message is intended as guidance, always read the full licence. When using these data you must cite them correctly using the citation given on the CEDA Data Catalogue record. grid English climatologyMeteorologyAtmosphere -1.427 -1.427 51.145 51.145 2008-01-01T00:00:00 Data are netCDF formatted NCAS British Atmospheric Data Centre (NCAS BADC) Data Center Contact +44(0)1235 446432 British Atmospheric Data Centre STFC Rutherford Appleton Laboratory Harwell Oxford OX11 0QX UK badc@rl.ac.uk distributor https://catalogue.ceda.ac.uk/uuid/3713e45f434e4e0bb5db6098dfba16e1 CEDA Data Catalogue Page Detail and access information for the resource information http://data.ceda.ac.uk/badc/chilbolton/data/gas-analyser-sonic-anemometer/ DOWNLOAD Download Data download dataset Commission Regulation (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services 2010-12-08 Data are collected by the Chilbolton Facility for Atmospheric and Radio Research (CFARR) before being checked by the instrument scientist and then delivered for archiving with the data centre.