Since 1967 the Meteorological Institute at Universität Hamburg, close-partnered
with the Max Planck Institute for
Meteorology , operates a
scientific, meteorological measuring site in Billwerder, a suburb of
Hamburg, Germany. It is located on an area of the NDR (the North German
Broadcasting Company) and consists of devices at a 300 m tall broadcasting mast
as well as at our own 10 m mast nearby on a meadow. Additionally, several
ground-based devices are installed outside the operator's hut beneath the
tall mast. In 1994 completely new equipment was installed, since 1995 measurement
runs continuously until today.
Geographic position and surroundings
The Hamburg Weather Mast is located in Hamburg-Billwerder, about 8 km
south-east of the city centre.
The geographic coordinates of the tall mast are
53° 31' 09,0'' N and 10° 06' 10,3'' E,
and 53° 31' 11,7'' N and 10° 06' 18,5'' O
of the 10 m mast respectively.
The site is located only 30 cm above German reference surface, so a device's
height above ground is nearly identical to its height above mean sea level.
The surroundings of the area are characterised by a mixture of agricultural
land, fallow ground, spoil areas, and sparsely populated hamlets in the East,
and industrial sites with mostly low buildings in the West. So the site is
located directly in the transition region between rural and urban kinds of
The meteorological equipment
The tall 300 m mast
The tall mast has six walkable platforms in height levels 50, 70, 110, 175,
250, and 280 m that can be accessed by a lift inside the mast. On each platform
there is attached a south-oriented cantilever arm that holds the
instruments. The distance between mast and instruments is nearly 6 m, the
diameter of the mast is 2 m. Each platform, except that at 70 m, is
equipped with the same instruments: A ventilated thermometer (Pt100) for
measuring the air temperature, a (relative) humidity sensor (Humicap) and
a 3d-ultra-sonic anemometer (METEK USA-1) for wind speed and direction as well
as turbulence quantities like sensible heat flux and momentum flux. At 50
up to 250 m there are fast CO2/H2O analyzers added to
the anemometers for latent heat and carbon dioxide fluxes (see below).
On the 70 m level there is a thermometer only. On the 110 m level a
dew point sensor (VTP6) is installed as a reference device.
The 10 m mast
The 10 m mast on the meadow holds the following devices:
The instrumentation in the level at 10 m equals those ones on the platforms of
the tall 300 m mast (temperature, humidity, wind, turbulence). In the height
of 2 m temperature and humidity is measured, too. There is mounted an
infra-red thermometer that "watches" the ground for measuring the
surface temperature. On top of the 10 m mast there are two irradiation
sensors for downward short-wave and long-wave irradiation from the upper
hemisphere (Kipp & Zonen Pyranometer CMP21 and Pyrgeometer CGR4) and, since 2014,
a total sky camera for cloud observations (VIVOTEK FE8174V).
Measuring of turbulence
In 2000 the meteorological equipment on both masts was enhanced by five
ultra-sonic anemometers/thermometers (USAT). They are mounted on top
of the 10 m mast and on the platforms at 50, 110, 175, and 250 m. In the mid of
2010 we added a sixth USAT at the 280 m platform.
These devices do not only measure wind speed and direction, but also
the (virtual) temperature and the turbulent fluctuations
of the three-dimensional wind vector. From these, amongst others the turbulent
heat and momentum fluxes can be determined. Additionally, the fastest gust
in each minute is determined out of the wind speed, that is measured with
a 20 Hz sample rate. For that, we define the largest gust in a minute as the
largest mean value over 3 seconds.
The ultra-sonic anemometers have replaced the prior used cup anemometers
and wind vanes.
For measuring the latent heat flux, in addition to the sensible heat flux,
fast infra-red CO2/H2O analyzers
(Licor LI-7500) have been mounted directly at the 3d anemometers at 10 up to
250 m in 2013. These analyzers measure the concentration of water vapor
and carbon dioxide simultaneously with the anemometer's wind vector.
In co-operation with the Institute of Soil Science a ground station
was established in mid of 2014 downto a depth of 1.2 m. The station is located
on the meadow near the 10 m mast. In five depths we are measuring the soil temperature, the
volumetric water content, and the soil water tension.
A pressure sensor is located in the operator's hut (Vaisala PTB). Nearby there
are devices for measuring clouds and precipitation.
The tipping bucket rain gauge registers the amount of rain based on a
resolution of 0.1 mm. The gauge can be heated in winter, so snow can also
The duration of precipitation can be registered exactly by an infra-red rain
sensor (IRSS 88), a photoelectric relay counting the rain drops falling through
an aperture of 12 cm × 3 cm. For each minute this device gives a 1 in case of
rain and a 0 otherwise.
In the mid of 2008 we mounted a micro rain radar (METEK MRR-2). This device
measures the rain rate, the fluid water content and the falling velocity of
the rain drops in steps of 35 m up to 1000 m.
A ceilometer determines the height of the cloud base by measuring the
run duration of an infra-red laser beam reflected by fluid water in the
atmosphere up to 15000 m.
Data sampling and transmitting
All data is sampled by several computers inside the operator's hut.
Most devices are queried once a second, but only averaged values are
stored each minute. The ultra-sonic anemometers run on a sampling frequency
of 20 Hz, the turbulent variables are calculated based on intervals of 1 and
5 minutes. The sampled data will be uploaded via DSL to our
server in the Geomatikum every 15 minutes, where additional operations
are made for creating the graphics on this website and storing the data
in our archive.
The following tabular gives an overview over all height levels and measured
variables. Alltogether there are about 50 independent measuring devices.
Variable/Device Height (m)
Temperature 2 10 50 70 110 175 250 280
Relative humidity 2 10 50 110 175 250 280
Dew point 110
Wind and turbulence 10 50 110 175 250 280
CO2/H2O concentration 10 50 110 175 250
Short-wave irradiation 10
Long-wave irradiation 10
Zenith rad. temperature 1
Atmospheric pressure 2
Amount of rain 2
Duration of rain 1
Surface temperature 0
Soil temperature –0.05 –0.1 –0.4 –0.8 –1.2
Vol. water content –0.05 –0.1 –0.8 –1.2
Soil water tension –0.05 –0.1 -0.4 –0.8 –1.2
Ceilometer 30 to 15000
Micro rain radar 35 to 1050
Weather camera (webcam) 50
Cloud camera 10
Photos: Ingo Lange