Geoscience Reference
In-Depth Information
Figure 1.8.
Time series of outlier rates (left panels) and gap rates (right panels) in the
HISTALP series of (a) air pressure, (b) air temperature, and (c) precipitation.
Outlier and gap rates in percentage (in relation to the amount
of available data) (from [AUE 07])
Generally, methods listed under a) to e) are implemented in the standard
workflow of the climate data section of NMHs. However, these quality control
procedures are always a compromise between strength of regulations and
acceptance of outliers. Moreover, everyday practice in data handling and database
management still produces erroneous data after passing the quality control
procedures mentioned above. Therefore, additional efforts are necessary to improve
the data quality, especially for longer-term climate data series. Such efforts should
not only include a quality check according to a) to e) but also a validation against
independent data as, for example:
- measured discharge against discharge at catchment level from hydrological
model forced by meteorological observations;
- measured snow water equivalent or snow height against modeled data from a
snow cover model forced by precipitation and air temperature;
- measured glacier mass balance against modeled data from glacier mass balance
model forced by meteorological data.
