Since 1972 the KNMI and partners have been operating a more than 200 m tall tower for boundary layer structure studies. This tower is located near Cabauw, The Netherlands, at 51.971° N, 4.927° E in a polder, 0.7 m above sea level. Besides the instruments mounted at the mast a number of additional instruments and sensor at the ground allow vertical sounding of atmosphere and clouds as well as the observation of the near surface radiation components. This is a list of the instruments currently in operation.
Besides measurements of the typical parameters like wind speed and direction, air and dew point temperature at the mast itself, there is an impressive suite of additional instruments at the surface: a wind profiler [since 1994], the Raman Lidar Caeli (Cesar Water Vapor, Aerosol, and Cloud Lidar) [since 2008], and surface radiation observation station as part of the BSRN [since 2005].
At the 213 m tall tower instruments are mounted at altitudes of 10, 20, 40, 80, 140 and 200 m allowing to measure the change of wind, temperature and humidity with altitude (see sample graphs of tower measurements from last 7 days).
Data of the Cesar Observatory are not available directly from ICDC. However the Cesar consortium is operating a web portal which allows easy access to the data of the Cesar observatory after registration: Cesar Data Portal.
The list of parameters following below contains just a small subset of the data measured. A good overview about the data that are actually available is given on the following web pages:
|air temperature [2m, 10m, 20m, 40m, 80m, 140m, 200m]||°C||1986*|
|dew point [2m, 10m, 20m, 40m, 80m, 140m 200m]||°C||1986*|
|wind speed [2m, 10m, 20m, 40m, 80m, 140m 200m]||m/s||1986*|
|wind direction [2m, 10m, 20m, 40m, 80m, 140m 200m]||deg||1986*|
|*) with gaps, since 05/2000 constant|
Period and temporal resolution:
- since year indicated in the table above or in the documentation
- temporal resolution: see documentation of the respective data set in the Cesar web portal
Coverage and spatial resolution:
- Local, Cabauw, The Netherlands
- Spatial resolution: none, vertical profiles
- Geographic longitude: 4.927°E
- Geographic latitude: 51.971°N
- Dimension: 1 column x 1 row x number of measurements vertically
- Altitude: (location itself is 0.7 m a.s.l.) 2 m, 10 m, 20 m, 40 m, 80 m, 140 m, and 200 m
- see documentation of the respective data set in the Cesar web portal.
Information about uncertainties and measurement errors can be taken from the documentations available via the Cesar data portal or requested directly from the responsible person.
People responsible for the data sets offered via the Cesar web portal can be found in the list of instruments currently in operation.
ICDC / CEN / University of Hamburg
email: stefan.kern (at) uni-hamburg.de
- Cesar DataBase Web Portal
- van Ulden, A. P., and J. Wieringa, 1996, Atmospheric boundary layer research at Cabauw. Bound. Lay. Meteorol., 78, 39-69.
- Beljaars, A. C. M., and F. C. Bosveld, 1997, Cabauw data for the validation of land surface parametrization schemes. J. Climate, 10, 1172-1193.
as requested via the Cesar web portal.