Mitteilungen DMG 02 / 2008 - Deutsche Meteorologische ...

2.2.5 Precipitation
The MOMAA station network also provides information
about precipitation. They are equipped with
YOUNG tipping bucket rain gauges with a resolution
of 0.2 mm per tip. In addition, 5 of 10 rain gauges can
be heated which makes it possible to measure solid precipitation.
www.youngusa.com
2.3 Data Logger
All MOMAA stations are equipped with CR1000 data
loggers from Campbell Scientific. They work like a
computer which collect the sensor data, process them
if necessary and store them in the required file format.
Data can be downloaded via the serial port or via a digital
GSM modem. www.campbellsci.com
2.4 Other instruments
Besides the MOMAA automatic weather station, IMGI
contributed additional instruments to COPS.
• Six DAVIS rain gauges which were set up in
vicinity to some NCAS AWSs as they were not
equipped for precipitation measurement
• One OTT PLUVIO weighing rain gauge at site
Besenfeld; www.ott-hydrometrie.de
• Two Disdrometers from THIESclima at sites
Hornisgrinde and Besenfeld www.thiesclima.de
3 MOMAA Network at COPS
3.1 Pre-field phase comparison
As the stations had only been purchased recently, we
did not have much experience in using them in the field.
In order to test the stations beforehand and to get an
overview about their working character and difference
in data recording, the stations were set up on the roof of
the IMGI. Preliminary quick looks were produced for
the detection of possible technical problems.
3.2 Field phase
As one of the major interests lies in the better understanding
of thermally-driven orographic flows on slo-
studenten
Fig. 2: Setup of MOMAA station sensors prior to field phase (left); the joy of meteorological field work in the Black Forest (right).
pes and along valleys the combined station network of
IMGI and NCAS had to be set up accordingly. Roughly
speaking, the NCAS covered the western slopes of the
northern Black Forest between Achern and Bühl and
the Murg valley, while the MOMAA stations were set
up along the Enz valley and at various hilltops and plateaus
along these two valleys. The data was collected
manually on a weekly basis. It was considered to do
it via GSM transmission but as the GSM network coverage
was very weak throughout the Black Forest, we
had to download the data directly from the stations.
The stations were operational from the end of week
26 until the end of week 31. Fortunately, the worst problems
we encountered throughout the whole measurement
period were bird droppings and insects in the rain
gauge.
3.3 Post-field phase comparison
After we had returned from COPS, the stations were set
up again in the IMGI weather garden for further testing.
One important test was a comparison of the rain gauges
by using medical drips with a certain amount of water.
There the stations remained installed until the end
of September. Quicklooks of this second comparison
measurements should be available from the beginning
of October.
3.4 Post-field data processing
Now that COPS is over and we have all the MOMAA
station data on our IMGI data base there is still a lot of
work to do until the data can be uploaded to the `World
Data Center for Climate‘ (WDCC).
• It will have to be decide which parameters will be
put in the final data files
• Quality control of the data: detection of outliers
and questionable data
• Create a continuous time series of data by eliminating
double times and by filling up missing
times with error flags
• Converting output files to netCDF format
Mitteilungen 02/2008
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