Chilbolton Facility for Atmospheric and Radio Research (CFARR): Gas analyser and Sonic anemometer data
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.
Default
Identification info
- Metadata Language
- English (en)
- Dataset Reference Date ()
- 2009-07-29T11:00:00
- Dataset Reference Date ()
- 2009-07-29T11:00:00
- Identifier
- NCAS British Atmospheric Data Centre (NCAS BADC) / 3713e45f434e4e0bb5db6098dfba16e1
- Maintenance and update frequency
- monthly
- Update scope
- dataset
- Keywords
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- CFARR
- gas analyser
- anenometer
- GEMET - INSPIRE themes, version 1.0 ()
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- atmospheric conditions
- Limitations on Public Access
- otherRestrictions
- Other constraints
- Access to these data is available to any registered CEDA user. Please Login or Register for an account to gain access.
- Use constraints
- otherRestrictions
- Spatial representation type
- grid
- Topic category
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- Climatology, meteorology, atmosphere
- Begin date
- 2008-01-01T00:00:00
- Code
- WGS 84
Distribution Information
- Data format
-
-
Data are netCDF formatted
()
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Data are netCDF formatted
()
- Resource Locator
-
CEDA Data Catalogue Page
Detail and access information for the resource
- Resource Locator
-
DOWNLOAD
Download Data
- Resource Locator
-
CEDA Data Catalogue Page
Detail and access information for the resource
- Resource Locator
-
DOWNLOAD
Download Data
- Quality Scope
- dataset
Report
- Dataset Reference Date ()
- 2010-12-08
- Statement
- 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.
Metadata
- File identifier
- 3713e45f434e4e0bb5db6098dfba16e1 XML
- Metadata Language
- English (en)
- Character set
- 8-bit variable size UCS Transfer Format, based on ISO/IEC 10646
- Parent identifier
- Chilbolton Facility for Atmospheric and Radio Research (CFARR): surface, radar and lidar measurements (1998-present) 7cbc3fc19bfa037a48ba4cba4b93544d
- Resource type
- dataset
- Metadata Date
- 2024-04-25T00:17:23
- Metadata standard name
- UK GEMINI
- Metadata standard version
- 2.3