Site description

The station is situated on the institute's roof at Heisenbergstraße 2.

Geographical latitude 51°58′09.34806” N
Geographical longitude 7°35'45.16282” E
Altitude AMSL 84 m

 

Measurand Instrument
Air temperature
Relative humidity		 Vaisala HMP155 (since 26.04.2022 15:30 CET)
Campbell HC2S3 (23.10.2015 15:00 to 26.04.2022 12:40 CET)
Young Type 41382VC (until 23.10.2015 12:00 CET)

Wind speed and
Wind direction

 Gill WindSonic (2D)
Young Wind Monitor 05103-45
Precipitation Tipping bucket
TRwS204
Air pressure

Vaisala PTB110A (since 2021-11-15, 14:00 CET)
Young 61302V (untIl 2021-11-15, 13:30 CET)
Shortwave radiation Kipp & Zonen Typ CMP6
Pyranometer
Visibility
Weather code		 Biral SWS100
Cloud base height
Total cloud cover		 Lufft Ceilometer
CHM 15k „Nimbus“

 

Information on the measuring devices

  • Temperature & Humidity

    The air temperature and the relative humidity are measured with a combined sensor. The sensor is housed in an instrument shelter (Gill) for protection against direct sunlight. The shelter and the sensor are installed at a height of 15 m above the institute's roof. Calibration is carried out by comparative measurements using a hand-operated aspiration psychrometer.

  • Wind Speed and Direction

    The wind is measured at a height of 15 m above the roof. The velocity is measured in m s-1. 1 m s-1 equals 3.6 km h-1 or 1.95 kn (knot ​​= 1 nautical mile per hour). The wind force according to Beaufort is determined by means of tables. The wind is measured at a height of 15 m above the roof. A wind direction of 90 ° means easterly wind (i.e. wind from east = E or O), 180 ° equals southerly wind = S, 270 ° is westerly wind = W, and 360 ° (as well 0 ° = N) represents northerly wind.

  • Precipitation

    The precipitation, the amount of water per time and area, is measured with a precipitation gauge (TRwS204). The inlet is mounted at 1.44 m above the institute's roof. A rainfall of 1 mm corresponds to one liter of water per square meter of soil surface. The precipitation is also measured with the Biral SWS100 (see Visibility), but not shown here. In the graphs, the cumulative precipitation for the time period of the display is shown.

  • Barometric Pressure

    The air pressure is measured with a conventional pressure sensor (Vaisala PTB110A). For a correction to "sea level" (for example for comparison with weather maps) approximately 9 hPa must be added.

  • Short-wave Radiation

    The short-wave radiation (incomming solar radiation) is measured with a pyranometer (Kipp & Zonen CMP 6). Nocturnal values ​​are zero, while during the course of the day the cloudcover can be concluded form the radiation. Reflected radiation and long-wave radiation (heat radiation of the surface and the atmosphere) are not recorded in the routine program.

  • Visibility & Weather Code

    The visibility is measured with a "Present Weather Sensor" (Biral SWS100) by scattering an infrared light signal. The detection of visibility is mainly used to detect the presence and density of fog. The maximum visibility captured is 2000 m. The SWS100 can also quantify precipitation and its type (rain, snow, etc.). This is used to characterize the weather according to WMO code 4680.

  • Cloud Base Height & Total Cloud Cover

    Cloud base height and total cloud cover are measured by a ceilometer (CHM 15k “Nimbus”, G. Lufft Mess- und Regeltechnik GmbH). It uses the Lidar technique (Lidar: light detection and ranging) to emit 5000-7000 short light pulses (wavelength 1064 nm) per second into the atmosphere. The receiver module registers the attenuated backscatter signal. Within an operating range of up to 15 kilometers, the ceilometer detects not only cloud base heights and cloud cover, but also penetration depths, vertical visibility, boundary layer height and the heights of aerosol layers.