Abstract: This data set contains time series of

surface pressure measured (at station level + 1 m) with a Vaisala PTB220A capacitive pressure sensor. [Basic meteorological data]
precipitation sum measured (at station level + 1 m) with an OTT Pluvio weighing rain gauge.[Basic meteorological data]
surface radiation flux densities (down-/upward, short-/longwave) and of the radiative surface temperature (at station level + 2 m) [Radiation data]
soil temperature and soil moisture measured at various depth levels down to – 1.5 m below short grass. [Soil data]
soil heat flux densities measured below short grass. [Soil data]
air temperature, relative humidity, and wind speed at various levels between 0.5 m and 10 m at the 10m-mast. [Tower data]
air temperature, relative humidity, wind speed, and wind direction at various levels between 10 m and 98 m at the 98m-tower. [Tower data]
mean values and variances of the wind components (u, v, w), sonic temperature, humidity and of the turbulent fluxes of momentum, sensible heat, and latent heat at three height levels (2.3 m, 50 m, 90 m). [Turbulence data]

All these data were measured at the boundary layer field site (GM) Falkenberg during the Field Experiment on Sub-mesoscale Spatio-Temporal Variability in Lindenberg (FESSTVaL) from May to August 2021. The Lindenberg Meteorological Observatory – Richard-Aßmann-Observatory supersite is operated by the German national meteorological service (Deutscher Wetterdienst, DWD). See also: Beyrich, F., W. Adam, 2007: Site and Data Report for the Lindenberg Reference Site in CEOP – Phase I. Offenbach a.M. - Selbstverlag des Deutschen Wetterdienstes: Berichte des Deutschen Wetterdienstes. Nr. 230, 55 pp. (ISSN 0072-4130)

Turbulence data are level-2 data as 30-minute statistics based on 20 Hz sampling organized in daily files. All other data are level-1 data as 10-minute averages (sums) based on 1 Hz sampling organized in daily files.

TableOfContents:

Basic Meteorological Data: rainfall amount; rainfall amount quality flag; air pressure; air pressure quality flag
Radiation Data: surface downwelling shortwave fllux; surface downwelling shortwave flux quality flag; surface upwelling shortwave flux; surface upwelling shortwave flux quality flag; surface downwelling longwave flux; surface downwelling longwave flux quality flag; surface upwelling longwave flux; surface upwelling longwave flux quality flag; surface temperature; surface temperature quality flag
Soil Data: volumetric soil moisture content; volumetric soil moisture content quality flag; soil temperature; soil temperature quality flag; downward heat flux in soil; downward heat flux in soil quality flag
Tower Data:

    10-m tower: air temperature; air temperature quality flag; relative humidity; relative humidity quality flag; wind speed; wind speed quality flag; wind direction; wind direction quality flag
    99-m tower: air temperature; air temperature quality flag; relative humidity; relative humidity quality flag; wind speed; wind speed quality flag; wind direction; wind direction quality flag


Turbulence Data: eastward wind u; northward wind v; upward air velocity w; standard deviation of u; standard deviation of v; standard deviation of w; sonic temperature; standard deviation of sonic temperature; wind speed; wind direction; friction velocity; friction velocity quality flag; upward momentum flux; tubulent kinetic energy; surface upward sensible heat flux; surface upward sensible heat flux quality flag; absolute humidity; surface upward water vapor flux; surface upward latent heat flux; surface upward latent heat flux quality flag; signal strength

Technical Info:

Basic Meteorological Data: dimension: 144 x 1; temporalExtent_startDate: 2021-05-01 00:10:00; temporalExtent_endDate: 2021-09-01 00:00:00; temporalResolution: 10; temporalResolutionUnit: minutes; spatialResolution: none; spatialResolutionUnit: none; horizontalResolutionXdirection: none; horizontalResolutionXdirectionUnit: none; horizontalResolutionYdirection: none; horizontalResolutionYdirectionUnit: none; verticalResolution: none; verticalResolutionUnit: meters; horizontalStart: 0; horizontalStartUnit: meters; horizontalEnd: 0; horizontalEndUnit: meters; instrumentNames: OTT Pluvio [precipitation], PTB220A [pressure]; instrumentType: weighing rain gauge [precipitation], capacitive pressure sensor [pressure]; instrumentLocation: both boundary layer field site (GM) Falkenberg (station level + 1 m); instrumentProvider: OTT Messtechnik GmbH [precipitation], Vaisala Oy [pressure]
Radiation Data: dimension: 144 x 1; temporalExtent_startDate: 2021-05-01 00:10:00; temporalExtent_endDate: 2021-09-01 00:00:00; temporalResolution: 1; temporalResolutionUnit: minutes; spatialResolution: none; spatialResolutionUnit: none; horizontalResolutionXdirection: none; horizontalResolutionXdirectionUnit: none; horizontalResolutionYdirection: none; horizontalResolutionYdirectionUnit: none; verticalResolution: none; verticalResolutionUnit: meters; horizontalStart: 0; horizontalStartUnit: meters; horizontalEnd: 0; horizontalEndUnit: meters; instrumentNames: CM24 (2 x CM21) [shortwave], DDPIR [longwave], KT15.82D [surface temperature]; instrumentType: precision pyranometer [shortwave], precision infrared radiometer [longwave], radiation pyrometer [surface temperature]; instrumentLocation: all boundary layer field site (GM) Falkenberg (station level + 2 m); instrumentProvider: Kipp&Zonen B.V. [shortwave], Eppley Lab Inc [longwave], Heitronics GmbH [surface temperature]
Soil Data: dimension: 144 x 9 [soil moisture], 144 x 11 [soil temperature], 144 x 3 [downward heatflux]; temporalExtent_startDate: 2021-05-01 00:10:00; temporalExtent_endDate: 2021-09-01 00:00:00; temporalResolution: 10; temporalResolutionUnit: minutes; spatialResolution: none; spatialResolutionUnit: none; horizontalResolutionXdirection: none; horizontalResolutionXdirectionUnit: none; horizontalResolutionYdirection: none; horizontalResolutionYdirectionUnit: none; verticalResolution: variable; verticalResolutionUnit: meters; horizontalStart: 0; horizontalStartUnit: meters; horizontalEnd: 0; horizontalEndUnit: meters; verticalStart: -0.05 [soil moisture], -0.02 [soil temperature], 0.0 [downward heatflux]; verticalStartUnit: meters; verticalEnd: 1.5 [soil moisture], -1.5 [soil temperature], -0.1 [downward heatflux]; verticalEndUnit: meters; instrumentNames: Trime-Pico-32/64 [soil moisture], WK 63.7 [soil temperature], HP3 [downward heatflux] ; instrumentType: TDR sonde [soil moisture], Platinum resistance thermometer [soil temperature], Soil heat flux plate [downward heatflux]; instrumentLocation: all boundary layer field site (GM) Falkenberg; instrumentProvider: IMKO GmbH [soil moisture], TMG GmbH [soil temperature], Rimco [downward heatflux]
Tower Data:

    10-m tower: dimension: 144 x 7 [all quantities except wind direction], 144 x 1 [wind direction]; temporalExtent_startDate: 2021-05-01 00:10:00; temporalExtent_endDate: 2021-09-01 00:00:00; temporalResolution: 10; temporalResolutionUnit: minutes; spatialResolution: none; spatialResolutionUnit: none; horizontalResolutionXdirection: none; horizontalResolutionXdirectionUnit: none; horizontalResolutionYdirection: none; horizontalResolutionYdirectionUnit: none; verticalResolution: variable; verticalResolutionUnit: meters; horizontalStart: 0; horizontalStartUnit: meters; horizontalEnd: 0; horizontalEndUnit: meters; verticalStart: 1.0 [all quantities except wind direction], 10.0 [wind direction]; verticalStartUnit: meters; verticalEnd: 10.0 [all quantities]; verticalEndUnit: meters; instrumentNames:  HMP45D [air temperature, humidity],  F460 [wind speed],  model 05103 [wind direction]; instrumentType: Psychrometer [air temperature, humidity], Cup anemometer [wind speed], Wind monitor [wind direction]; instrumentLocation: all boundary layer field site (GM) Falkenberg; instrumentProvider: Vaisala Oy [air temperature, humidity], Climatronics Corp. [wind speed], R.M. Young Company [wind direction]
    99-m tower: 144 x 6 [all quantities except wind direction], 144 x 2 [wind direction]; temporalExtent_startDate: 2021-05-01 00:10:00; temporalExtent_endDate: 2021-09-01 00:00:00; temporalResolution: 10; temporalResolutionUnit: minutes; spatialResolution: none; spatialResolutionUnit: none; horizontalResolutionXdirection: none; horizontalResolutionXdirectionUnit: none; horizontalResolutionYdirection: none; horizontalResolutionYdirectionUnit: none; verticalResolution: variable; verticalResolutionUnit: meters; horizontalStart: 0; horizontalStartUnit: meters; horizontalEnd: 0; horizontalEndUnit: meters; verticalStart: 10.0 [all quantities except wind direction], 40.0 [wind direction]; verticalStartUnit: meters; verticalEnd: 98.0 [all quantities]; verticalEndUnit: meters; instrumentNames: HMP45D [air temperature, humidity], 4.3303.22.000 [wind speed], 4.3121.32.000 [wind direction]; instrumentType: Psychrometer [air temperature, humidity], Cup anemometer [wind speed], Wind vane [wind direction]; instrumentLocation: all boundary layer field site (GM) Falkenberg; instrumentProvider: Vaisala Oy [air temperature, humidity], Thies Klima [wind speed], Thies Klima [wind direction]


Turbulence Data: dimension: 48 x 1 x 3 [turb00: 2.3 m, turb01: 50.0 m, turb02: 90.0 m]; temporalExtent_startDate: 2021-05-01 00:30:00; temporalExtent_endDate: 2021-09-01 00:00:00; temporalResolution: 30; temporalResolutionUnit: minutes; spatialResolution: none; spatialResolutionUnit: none; horizontalResolutionXdirection: none; horizontalResolutionXdirectionUnit: none; horizontalResolutionYdirection: none; horizontalResolutionYdirectionUnit: none; verticalResolution: variable; verticalResolutionUnit: meters; horizontalStart: 0; horizontalStartUnit: meters; horizontalEnd: 0; horizontalEndUnit: meters; verticalStart: 2.3; verticalStartUnit: meters; verticalEnd: 90.0; verticalEndUnit: meters; instrumentNames: USA-1 [wind and temperature fluctuations], LI-7500RS [water vapor fluctuations] ; instrumentType:  Sonic anemometer [wind and temperature fluctuations], Infrared gas analyser [water vapor fluctuations]; instrumentLocation: all boundary layer field site (GM) Falkenberg; instrumentProvider: Metek GmbH [wind and temperature fluctuations], LiCor Inc. [water vapor fluctuations]

Methods:

Basic Meteorological Data: Air pressure sensor accuracy is specified by the manufacturer with 0.1 hPa at 20 °C. Quality control includes range tests and an intercomparison versus a second independent pressure measurement. Precipitation sensor accuracy is specified by the manufacturer with 0.04 mm. Quality control includes intercomparison versus a second independent precipitation measurement at the same site using a Lambrecht rain[e] H3 sensor. Each measured value is accompanied by a quality flag where 0 = data value missing, 1 = good quality, 2 = interpolated or gap-filled by data from an alternative sensor, 3 = dubious quality, 4 = bad quality, 9 = no quality information available.
Radiation Data: Radiation flux sensors are operated in ventilated shields. The uncertainty is estimated from internal comparisons at ± 5 W/m2 (or 1.5 % - whichever is larger) for shortwave components. The longwave uncertainty is less than ± 5 W/m2. The radiation sensors operated at GM Falkenberg are regularly changed and compared versus reference sensors directly traceable to the World Radiometric Reference (WRR) and the World Infrared Standard Group (WISG) for shortwave and longwave radiation, respectively.
For the infrared thermometer, sensor accuracy is specified by the manufacturer with 0.5 K. Quality control follows the recommendations of the WMO baseline surface radiation network (BSRN). It includes absolute value and albedo range tests, intercomparison versus a second independent radiation flux measurement at the same site, cross-checks of the surface temperature derived from the outgoing longwave radiation versus the direct surface temperature measurement and of the shortwave radiation components vs. photosynthetically active radiation (PAR) measured with a LI190SZ photodiode sensor. Temperatures of the emitting surfaces derived from the longwave radiation components are checked for plausibility vs. surface and ambient air temperature. Each measured value is accompanied by a quality flag where 0 = data value missing, 1 = good quality, 2 = interpolated or gap-filled by data from an alternative sensor, 3 = dubious quality, 4 = bad quality, 9 = no quality information available.
Soil Data: Soil temperature and volumetric soil moisture content data are based on measurements with platinum resistance thermometers and TDR sondes buried at various depth levels below short grass. Up to four sensors are available at each depth. The values reported represent an average of all measurements at a given depth that do not deviate by more than 1 K for soil temperature (2 K at -0.05 m) and the maximum of either 5 Vol-% or 50 % of the mean value for the volumetric soil moisture content. Based on long-term inter-comparison experiments, the uncertainty of the volumetric soil moisture content values can be estimated less than 3 Vol-% in the upper 0.4 m and less then 5 Vol-% below 1 m. In the intermediate layer (0.4 m to 1 m) heterogeneity of the soil may cause local differences up to 10 Vol-%. Soil heat flux data are based on measurements with flux plates HP3 (Rimco) buried at -0.05 m and -0.1 m below short grass. The values reported represent an average of measurements with up to four sensors at each depth. Each measured value is accompanied by a quality flag where 0 = data value missing, 1 = good quality, 2 = interpolated or gap-filled by data from an alternative sensor, 3 = dubious quality, 4 = bad quality, 9 = no quality information available. Flag = 1 is assigned if the difference between the sensors is less than 10 W/m2 or 30 % of the mean value.
Tower Data: At the 10-m tower, air temperature and relative humidity are measured simultaneously by HMP45D and by an aspirated Frankenberger psychrometer in actively aspirated radiation shields. The accuracies of the sensors are specified by the manufacturers as follows: Air temperature: 1/3 DIN IEC 751 Class B // Relative humidity: 2 % (3 % above 90 % relative humidity) // Wind speed: 0.07 m/s or 1 % whichever is greater. An offset correction is applied to the HMP45D air temperature data based on a regular inter-comparison of the HMP45D temperature measurements against psychrometer temperature measurements during night-time. This offset correction typically is in the range 0.05 - 0.20 K, it has been found to be almost constant in time (variations of less than 0.05 K). A correction for the HMP45D was derived by minimising the rmsd when compared to the psychrometer data. The coefficients of the non-linear (polynomial) regression model for the FESSTVaL period were based on parallel measurements in April 2021 and in July 2021. Relative humidity values > 100% are set equal to 100%. Due to the construction of the 10m mast there are flow distortion effects on the wind speed measurements for winds from the sector between 35 degree and 85 degree, these data are flagged correspondingly. Wind speed values smaller than 0.13 m/s are interpreted as calm and set to zero. In this case corresponding wind direction is set equal to zero as well. Note that wind direction equal to zero marks calm conditions, while wind from North is indicated by a wind direction of 360 degree. Quality control includes a regular comparison of the air temperature and relative humidity differences of the HMP45D vs. the psychrometer measurements. For wind speed, an increase with height is assumed except for very low winds. Each measured value is accompanied by a quality where 0 = data value missing, 1 = good quality, 2 = interpolated or gap-filled by data from an alternative sensor, 3 = dubious quality, 4 = bad quality, 9 = no quality information available
At the 99-m tower air temperature and relative humidity are measured simultaneously in actively aspirated radiation shields  For humidity a HMP45D and a Thygan VTP06 dewpoint mirror are used. The accuracies of the sensors are specified by the manufacturers as follows: Air temperature: 1/3 DIN IEC 751 Class B // Relative humidity: 2 %  (3 % above 90 % relative humidity) // Wind speed: 0.3 ms-1 (or: 2 %) rms. An offset correction is applied to the HMP45D air temperature data based on a regular inter-comparison of the HMP45D temperature measurements against psychrometer temperature measurements during night-time. This offset correction typically is in the range 0.05 - 0.20 K, it has been found to be almost constant in time (variations of less than 0.05 K). A polynomial correction for the HMP45D was derived by minimising the rmsd when compared to the dewpoint mirror data. The coefficients of the non-linear (polynomial) regression model for the FESSTVaL period were based on parallel measurements in April 2021 and in July 2021. Relative humidity values > 100% are set equal to 100%. Wind measurements at the Falkenberg tower are performed on three booms roughly pointing towards N, S, and W, respectively, at each level. Wind direction is measured at the 40 m and 98 m levels only. The representative wind direction is determined from the measurements at the three booms by vector averaging of those measurements which differ by less than 10 degree - if all three measurements differ by > 10 degree, a comparison with the wind direction from the level below (40 m vs. 11 m at the 10m-mast, 98 m vs. 40 m) is performed and the wind direction closest to that is selected. Wind direction is linearly interpolated between 11 m and 40 m, and between 40 m and 98 m to obtain an estimate at the intermediate levels for wind speed sensor selection. The representative wind speed measurement is then selected in dependence on wind direction. For wind speeds < 2 m/s, the maximum of the three values at a given level is taken as the representative one. Wind speed values smaller than 0.3 m/s are interpreted as calm and set to zero. In this case corresponding wind direction is set equal to zero as well. Note that wind direction equal to zero marks calm conditions, while wind from North is indicated by a wind direction of 360 degree. Quality control includes a regular comparison of the air temperature and relative humidity differences of the HMP45D vs. the psychrometer temperature and dewpoint mirror humidity measurements. For wind speed, an increase with height is assumed except for low winds. Each measured value is accompanied by a quality flag where 0 = data value missing, 1 = good quality, 2 = interpolated or gap-filled by data from an alternative sensor, 3 = dubious quality, 4 = bad quality, 9 = no quality information available.

Turbulence Data: Two eddy-covariance (EC) systems at a measuring height of 2.3 m are mounted on top of thin pile masts, which are installed at the eastern and western sides of the GM Falkenberg, respectively. In dependence on the prevailing wind direction either the one or the other represents the characteristics of the grassland surface. The two EC systems at 50 m and 90 m on the 99m meteorological tower are each mounted at the tip of a boom pointing towards 190 degree at a distance of 5 m from the tower construction. The booms are fixed to the west side of the lattice tower which has a quadratic cross-section of 1.1 m side length. The measurements are disturbed by lee effects of the tower for wind directions between 0 degree and 55 degree. Weaker upstream effects cannot be ruled out for wind directions between 170 degree and 230 degree, but are difficult to prove. The accuracies of the sensors forming an eddy-covariance (EC) system are specified by the manufacturers as follows: wind vector components: 0.075 ms-1 or 1.5 % of reading // absolute humidity: <1 % of reading. The raw data from the sonic and from the infrared gas analyser (IRGA) based on 20 Hz sampling were processed using the EddyPro V7.0.9 software package provided by LiCor Inc. The following settings were applied:

    Double rotation of the sonic co-ordinate system acc. to Wilczak et al. (2001, Boundary-Layer Meteorol. 99, 127-150)
    Despiking and raw data statistical screening (excluding the test for angle of attack and steadiness of horizontal wind) acc. to Vickers and Mahrt (1997, J. Atmos. Ocean. Technol. 14, 512-526)
    Band pass spectral correction acc. to Moncrieff et al. (1997, J. Hydrol, 188-189, 589-611; 2004, in: Handbook of micrometeorology: a guide for surface flux measurements, eds. Lee, X., W. J. Massman and B. E. Law. Dordrecht: Kluwer Academic, 7-31)
    Buoyancy and crosswind correction acc. to Schotanus et al. (1983, Boundary-Layer Meteorol. 26, 81-93)
    Compensation of density fluctuations acc. to Webb et al. (1980, Quart. J. Roy. Meteorol. Soc. 106, 85-100)
    Quality control of the fluxes includes the stationarity and integral-turbulence-characteristics tests acc. to Mauder et al. (2013, Agric. Forest Meteorol. 169, 122-135), which are implemented in the EddyPro software. These tests are complemented by (i) climatologically-based value range tests, (ii) comparison of net radiation vs. energy fluxes, (iii) validation of ratio of wind speed and friction velocity, and (iv) tests to evaluate the sign of the measured fluxes using gradient measurements (finite differences of the mean variables) provided that both the gradients and the fluxes are not too small. The LI7500 RS signal strength (variable 19) may serve as an additional quality indicator of the IRGA measurement. To validate the quality of the sonic measurements, precipitation measurements are taken into account. All EC system measured quantities such as the wind speed, humidity and temperature are compared to other operational measuring systems in the surrounding area.
    Each derived flux value is accompanied by a quality flag where 0 = data value missing, 1 = bad quality, 2 = dubious quality, 3 = good quality.

Units: (see TableOfContents)

Basic Meteorological Data: kg m-2;1;pa;1
Radiation Data: W m-2;1;W m-2;1;W m-2;1;W m-2;1;K;1
Soil Data: Vol-%;1;K;1;W m-2;1
Tower Data [both towers]: K;1;1;1;m s-1;1;degrees;1
Turbulence Data: m s-1;m s-1;m s-1;m s-1;m s-1;m s-1;K;K;m s-1;degrees;m s-1;1;N m-2;J kg-1;W m-2;1;kg m-3;kg m-2s-1;W m-2;1;1

geoLocations:

BoundingBox:  westBoundLongitude: 14.1221 degrees East; eastBoundLongitude: 14.1223 degrees East; southBoundLatidude: 52.1664 degrees North; northBoundLatitude: 52.1666 degrees North; geoLocationPlace: Germany, UTM zone 33U
Locations:

    Basic Meteorological Data: 52.1665 °N, 14.1222 °E, 73 m above mean sea level, 1 m above ground
    Radiation Data: 52.1665 °N, 14.1222 °E, 73 m above mean sea level, 2.0 m above ground
    Soil Data: 52.1665 °N, 14.1222 °E, 73 m above mean sea level, 0.05 m to 1.5 m below ground
    Tower Data: 52.1665 °N, 14.1222 °E, 73 m above mean sea level, 0.5 m to 98.0 m above ground
    Turbulence Data: 52.1665 °N, 14.1222 °E, 73 m above mean sea level, 2.3 m to 90.0 m above ground

Size: Data (mostly level 1, Turbulence Data level 2) are packed into compressed tar-archives. Their sizes range between 0.2 Mbyte and 2.2 Mbyte.

Format: netCDF

DataSources: Single site ground-based instrument measurements, see "Technical Info" for instruments

Contact: claudia.becker (at) dwd.de; nadja.samtleben (at) dwd.de; frank.beyrich (at) dwd.de

Web page: https://www.cen.uni-hamburg.de/en/icdc/data/atmosphere/samd-st-datasets/samd-st-fesstval/sups-rao-falkenberg.html

see also: https://www.cen.uni-hamburg.de/en/icdc/research/samd/observational-data/short-term-observations/fesstval.html

FESSTVaL is funded by the Deutscher Wetterdienst within the Hans-Ertel Centre for Weather Research.

{"references": ["Beyrich, F., W. Adam, 2007: Site and Data Report for the Lindenberg Reference Site in CEOP \u2013 Phase I. Offenbach a.M. - Selbstverlag des Deutschen Wetterdienstes: Berichte des Deutschen Wetterdienstes. Nr. 230, 55 pp. (ISSN 0072-4130)"]}