Note sure what dataset you need? - This might help.
Last updated: 28.02.2018 by Roger Brugge, clarifying scalar wind speeds and vector wind directions
Variables from the following datasets are currently available for download - click on an entry for further information:
Data from this dataset are the raw values as logged by the METFiDAS observing system.
The variables have been converted from the measured voltages/currents into the appropriate
meteorological units. The observations are determined as intervals of 1 second.
Currently, these variables can be extracted:
- Stevenson screen variables at 1.2 metre height: Relative humidity, dry bulb temperature, wet bulb temperature
- Kipp-Zonen CSD instrument: sunshine duration every 1 second, direct beam radiation
- Ground surface temperatures: concrete, grass, bare soil
- Sub surface temperatures under a grass surface: at depths of 5, 10, 20, 30, 50 and 100 cm
- Solar radiation: direct beam, global, diffuse
- Data from Channel 28, Channel 32, Channel 33, R38
- Net radiative heat flux, ground heat flux
- Atmospheric electricity variables: potential gradient, corrugated plate current, flat plate current, point discharge
- Winds from the 10 metre mast: direction at 5 m and 10 m, speed at 2 m, 5 m and 10 m
- Rainfall: amounts falling every 1 second in 0.2 mm amounts
- Atmospheric pressure: at station level
- Upward and downward radiation: shortwave and longwave (the latter uncorrected for instrument (CNR4) temperature)
- Student boundary layer mast variables: winds at 0.56 m, 0.8 m, 1.12 m, 1.6 m, 2.24 m, 3.2 m, 4.48 m and 6.4 m; air temperatures at 0.56 m, 1.12 m, 2.24 m, 4.48 m
- Propellor U,V and W wind components from Gill fast response bi-directional propeller anemometers
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These data are 5-minute averages of the raw data measurements, the time of
each measurement being the end time of the 5-minute period. Currently,
these variables can be extracted:
- Stevenson screen variables at 1.2 metre height: Relative humidity, dry bulb temperature, wet bulb temperature
- Kipp-Zonen CSD instrument: sunshine duration over 5 minutes, direct beam radiation
- Ground surface temperatures: concrete, grass, bare soil
- Sub surface temperatures under a grass surface: at depths of 5, 10, 20, 30, 50 and 100 cm
- Solar radiation: direct beam, global, diffuse
- Data from Channel 28, Channel 32, Channel 33, R38
- Net radiative heat flux, ground heat flux
- Atmospheric electricity variables: potential gradient, corrugated plate current, flat plate current, point discharge
- Winds from the 10 metre mast: direction at 5 m and 10 m, speed at 2 m, 5 m and 10 m
- Rainfall: amounts falling every 5 minutes in 0.2 mm amounts
- Atmospheric pressure: at station level
- Upward and downward radiation: shortwave and longwave (the latter uncorrected for instrument (CNR4) temperature)
- Student boundary layer mast variables: winds at 0.56 m, 0.8 m, 1.12 m, 1.6 m, 2.24 m, 3.2 m, 4.48 m and 6.4 m; air temperatures at 0.56 m, 1.12 m, 2.24 m, 4.48 m
- Propellor U,V and W wind components from Gill fast response bi-directional propeller anemometers
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Data in this section are the highest and lowest values (and the times
of occurrence) of the 1-second measured values, the extremes being
determined over a 5-minute interval. The extremes are output with a
reference time of the end time of the 5-minute period. Currently,
the extreme values and occurrence times of the following variables
can be extracted:
- Stevenson screen variables at 1.2 metre height: Relative humidity, dry bulb temperature, wet bulb temperature
- Kipp-Zonen CSD instrument: sunshine duration over 5 minutes, direct beam radiation
- Ground surface temperatures: concrete, grass, bare soil
- Sub surface temperatures under a grass surface: at depths of 5, 10, 20, 30, 50 and 100 cm
- Solar radiation: direct beam, global, diffuse
- Data from Channel 28, Channel 32, Channel 33, R38
- Net radiative heat flux, ground heat flux
- Atmospheric electricity variables: potential gradient, corrugated plate current, flat plate current, point discharge
- Winds from the 10 metre mast: direction at 5 m and 10 m, speed at 2 m, 5 m and 10 m
- Rainfall: amounts falling every 1 second in 0.2 mm amounts
- Atmospheric pressure: at station level
- Upward and downward radiation: shortwave and longwave (the latter uncorrected for instrument (CNR4) temperature)
- Student boundary layer mast variables: winds at 0.56 m, 0.8 m, 1.12 m, 1.6 m, 2.24 m, 3.2 m, 4.48 m and 6.4 m; air temperatures at 0.56 m, 1.12 m, 2.24 m, 4.48 m
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The variables output in this category are those of measurements
at 1-second intervals converted to WMO-standardized values over
differing time intervals. The variables are output every
5 minutes with the time value assigned being that at the end
of the 5-minute period.
The following averaging periods are in use:
- Air temperature (and related variables), pressure - 1 minute
- Radiation variables - 10 seconds
- Wind - 10-minute scalar means for speed and vector means for direction; 3-second arithmetic means for gusts
Currently, these variables can be output:
- Stevenson screen variables at 1.2 metre height, averaged over 1 minute - dry bulb temperature, measured wet bulb temperature, measured relative humidity, derived wet bulb temperature (from dry bulb and relative humidity), derived vapour pressure (from dry bulb and relative humidity), derived dew point (from dry bulb and relative humidity). The derived values are calculated at 1-second intervals and then averaged over 1 minute
- Kipp-Zonen CSD instrument - 5-minute sunshine total, accumulated sunshine since 0000 UTC
- Ground surface temperatures averaged over 1 minute: concrete, grass, bare soil
- Sub surface temperatures under a grass surface averaged over 1 minute: at depths of 5, 10, 20, 30, 50 and 100 cm
- Solar radiation; 10-second averages are output every 5 minutes: direct beam, global, diffuse; also the direct beam radiation calculated from the CSD instrument
- Solar radiation - values are totalled over 5 minutes: accumulated global solar radiation since 0000 UTC
- Net radiative heat flux, ground heat flux; these are 10-second averages output every 5 minutes
- Rainfall - 5-minute rainfall total, accumulated rainfall since 0000 UTC
- Run of wind, output at 5-minute intervals - at heights of 2 m, 5 m, 10 m
- Pressure - averaged over 1 minute to compute the station level pressure; MSL pressure is then determined at 1 minute intervals from the station pressure and air temperature; values the output at 5 minute intervals
- Maximum wind gust - determined by averaging the 1-second wind speeds over 3-seconds; values then output at 5-minute intervals at heights of 5 m and 10 m
- Mean wind speed and direction - these are vector(scalar) means over 10 minutes for wind direction(speed) calculated using 1-second interval measurements; 5 m wind speed, 5 m wind direction, 10 m wind speed and 10 m wind direction are calculated and output at 5 minute intervals
- Radiation quantities; these are 10-second averages output every 5 minutes - CNR4 radiometer temperature, shortwave-downward radiation, shortwave-upward radiation, longwave-downward radiation (uncorrected), longwave-upward radiation (uncorrected), longwave-downward radiation (corrected for instrument temperature), longwave-upward radiation (uncorrected for instrument temperature)
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The variables output in this category are those of measurements at
1-second intervals converted to WMO-standardized values over differing
time intervals. Maximum and minimum values in each five minute period are output - these values being determined from values at 1-minute intervals.
Extremes of the following variables are output:
- dry bulb temperature, measured wet bulb temperature, measured relative humidity
- Ground surface temperatures: concrete, grass, bare soil
- Sub surface temperatures under a grass surface at depths of 5, 10, 20, 30, 50 and 100 cm
- Solar radiation: direct beam, global, diffuse
- Net radiative heat flux, ground heat flux
- Pressure and MSL pressure
- Radiation quantities: CNR4 radiometer temperature, shortwave-downward radiation, shortwave-upward radiation, longwave-downward radiation (uncorrected), longwave-upward radiation (uncorrected), longwave-downward radiation (corrected for instrument temperature), longwave-upward radiation (uncorrected for instrument temperature)
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The variables output in this category are those of measurements at
1-second intervals converted to WMO-standardized values over differing
time intervals. The variables are output every 60 minutes with the time
value assigned being that at the end of the 5-minute period.
The following averaging periods are in use:
- Air temperature (and related variables), pressure - 1 minute
- Radiation variables - 10 seconds
- Wind - 10-minute scalar means for speed and vector means for direction; 3-second arithmetic means for gusts
Currently, these variables can be output:
- Stevenson screen variables at 1.2 metre height, averaged over 1 minute - dry bulb temperature, measured wet bulb temperature, measured relative humidity, derived wet bulb temperature (from dry bulb and relative humidity), derived vapour pressure (from dry bulb and relative humidity), derived dew point (from dry bulb and relative humidity). The derived values are calculated at 1-second intervals and then averaged over 1 minute
- Kipp-Zonen CSD instrument - 60-minute sunshine total, accumulated sunshine since 0000 UTC
- Ground surface temperatures averaged over 1 minute: concrete, grass, bare soil
- Sub surface temperatures under a grass surface averaged over 1 minute: at depths of 5, 10, 20, 30, 50 and 100 cm
- Solar radiation; 10-second averages are output every 60 minutes: direct beam, global, diffuse; also the direct beam radiation calculated from the CSD instrument
- Solar radiation - values are totalled over 60 minutes: accumulated global solar radiation since 0000 UTC
- Net radiative heat flux, ground heat flux; these are 10-second averages output every 5 minutes
- Rainfall - 60-minute rainfall total, accumulated rainfall since 0000 UTC
- Run of wind, output at 5-minute intervals - at heights of 2 m, 5 m, 10 m
- Pressure - averaged over 1 minute to compute the station level pressure; MSL pressure is then determined at 1 minute intervals from the station pressure and air temperature; values the output at 60 minute intervals
- Maximum wind gust - determined by averaging the 1-second wind speeds over 3-seconds; values then output at 60-minute intervals at heights of 5 m and 10 m
- Mean wind speed and direction - these are vector(scalar) means over 10 minutes for wind direction(speed) calculated using 1-second interval measurements; 5 m wind speed, 5 m wind direction, 10 m wind speed and 10 m wind direction are calculated and output at 5 minute intervals
- Radiation quantities; these are 10-second averages output every 5 minutes - CNR4 radiometer temperature, shortwave-downward radiation, shortwave-upward radiation, longwave-downward radiation (uncorrected), longwave-upward radiation (uncorrected), longwave-downward radiation (corrected for instrument temperature), longwave-upward radiation (uncorrected for instrument temperature)
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The variables output in this category are those of measurements at
1-second intervals converted to WMO-standardized values over differing
time intervals. Maximum and minimum values in each five minute period
are output - these values being determined from values at 1-minute intervals.
Extremes of the following variables are output:
- dry bulb temperature, measured wet bulb temperature, measured relative humidity
- Ground surface temperatures: concrete, grass, bare soil
- Sub surface temperatures under a grass surface at depths of 5, 10, 20, 30, 50 and 100 cm
- Pressure and MSL pressure
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The variables output in this category are WMO-standard
derived values applicable at 0900 UTC (and can be compared directly to the
manual observations made at this time. The following are available:
- dry bulb temperature, derived wet bulb temperature, derived dew point, derived vapour pressure, relative humidity
- Maximum temperature for yesterday ending 0900 UTC today
- Minimum temperature ending 0900 UTC today
- Grass minimum/concrete/bare soil temperature ending 0900 UTC
- 0900 UTC soil temperatures under grass at depths of 5, 10, 20, 30, 50 and 100 cm
- 0900 UTC wind direction and wind speed at 10 m
- 0900 UTC MSL pressure
- Rainfall for yesterday ending 0900 UTC today
- Sunshine duration for yesterday, ending 2400 UTC last night
- Global solar radiation accumulation for yesterday, ending 2400 UTC last night
- 0000-2400 UTC maximum wind gust at 10 m for yesterday
- 2m run of wind for yesterday ending 0900 UTC today
- 10 m run of wind for yesterday ending 0900 UTC today
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The variables output at 0.1 second intervals are as follows:
- U - zonal wind component
- V - meridional wind component
- T - air temperature
- W - vertical wind component
- H2O - water vapour concentration
- CO2 - carbon dioxide concentration
- P - air pressure
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The variables output as 5-minute averages are as follows:
- Wind speed at heights of 0.56 m, 0.8 m, 1.12 m, 1.6 m, 2 m, 2.24 m, 3.2 m, 4.48 m, 5 m, 6.4m and 10 m
- Air temperature at heights of 0.56 m, 1.12 m, 2,24 m, 4.48 m
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The following are available, computed using observations at 0.1 second intervals:
- q - specific humidity
- WS - horizontal wind speed
- dir - wind direction
- zL - atmospheric stability parameter (z=3m)
- L - Monin-Obhukov length
- Tsonic - mean sonic temperature
- ustar - friction velocity
- nSamples - number of data samples in the results at the current time
- cov_uv - covariance of U and V wind components
- cov_uw - covariance of U and W wind components
- cov_vw - covariance of V and W wind components
- Q_H - turbulent sensible heat flux
- Q_E - turbulent latent heat flux
- C_CO2 - carbon dioxide concentration
- F_CO2 - turbulent carbon dioxide flux
- sd_Tsonic - standard deviation of sonic temperature
- sd_u - standard deviation of U wind component
- sd_v - standard deviation of V wind component
- sd_w - standard deviation of W wind component
- sd_C_CO2 - standard deviation of carbon dioxide concentration
- sd_q - standard deviation of specific humidity
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The following are available, computed using observations at 2-3 second intervals:
- Base1_mean - mean cloud base height of the lowest cloud layer
- Base1_sd - standard deviation of the cloud base height of the lowest cloud layer
- Base2_mean - mean cloud base height of the middle cloud layer (if present)
- Base2_sd - standard deviation of the cloud base height of the middle cloud layer (if present)
- Base3_mean - mean cloud base height of the third highest cloud layer (if present)
- Base3_sd - standard deviation of the cloud base height of the third highest cloud layer (if present)
- Base1_min - minimum height of the lowest cloud layer
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The following are available, computed using observations at 2-3 second intervals:
- Base1_mean - mean cloud base height of the lowest cloud layer
- Base1_sd - standard deviation of the cloud base height of the lowest cloud layer
- Base2_mean - mean cloud base height of the middle cloud layer (if present)
- Base2_sd - standard deviation of the cloud base height of the middle cloud layer (if present)
- Base3_mean - mean cloud base height of the third highest cloud layer (if present)
- Base3_sd - standard deviation of the cloud base height of the third highest cloud layer (if present)
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