WG-ROUND and DAQUAMAP report

Inga Groehn 1) , Christian Häberli 1),2), and Reinhold Steinacker 1)
1) Dept. of Meteorology and Geophysics, University of Vienna, 1090 Vienna, Austria
2) MeteoSwiss, 8044 Zurich, Switzerland

Introduction and Motivation

Instead of organising a WGROUND-meeting during the last MAP-Meeting in Schliersee, Germany, a second workshop on quality control of meteorological data in MAP was planned and was finally held in Vienna, Austria on 21st -22nd of February 2002. 19 persons from 9 institutions in 6 countries participated.

As the DAQUAMAP-project is still going on until the end of this year, data providers and users of the quality control results had the opportunity during this workshop to express their needs and make comments. But also the possibility to exchange experience about the use of various quality control tools has been used. In the following a brief summary of the scientific presentations and the main results of the Working Group discussions will be presented.

Short summary of scientific presentations (in chronological order)

The first scientific presentation about MAP-SOP Alpine Precipitation Analysis (see for more information: FreiHaeller.pdf) was given by Esther Häller from the Institute for Atmospheric and Climate Science at the ETH in Zurich, Switzerland (MAP Data Centre). The daily precipitation observations 06-06 UTC from the MAP database in a high-resolution rain-gauge network (about 5000 stations) over the SOP were analysed and the results outlined. A new version of MAP-SOP Alpine Precipitation Analysis was announced and will be done again in the future by Christoph Frei and Esther Häller. Then e.g. ITAMAP2.0 1 and HZB 2 (about 880 stations more than in the present version) will be included.

An area quality control was presented by Radim Tolasz from the Czech Hydrometeorological Institute in Ostrava – Poruba. The tool used is CLIDATA and results are visualised on a GIS. The method itself (catchword: empirical probability) and its advantages were presented and examples were shown.

The spatial quality control method for temperature data in the Czech Republic 1961-2000 was described by Vít Kveton, Prague.

The focus of the whole afternoon session was on DAQUAMAP. At first, Christian Häberli gave a presentation about the method which is applied in DAQUAMAP (and VERA). Then, the two DAQUAMAP- homepages were presented. The two homepages are identical with two exceptions: The homepage at http://www.univie.ac.at/IMG-Wien/ daquamap/ includes information for the data providers. There they have the possibility to check the DAQUAMAP-results of their institute before they are published on the other DAQUAMAP-homepage in the password protected MAP area on the MDC (http://www.map.meteoswiss.ch/mm-doc/daquamap/daquamain.html). In some cases very helpful additional comments from the data providers are included. In the second half of the workshop, the participants checked out the DAQUAMAP-results of their institution. This was a good occasion to ask questions and discuss the results thoroughly.

In the following discussion it was proposed to have a special workshop about the interpretation of the DAQUAMAP results of the SOP for the regional weather services in Northern Italy.
Esther Häller from the MAP Data Centre gave a lecture on the status of the SOP data base. (For information see http://www.map.meteoswiss.ch/sop-doc/sop_info/sop_info.htm; ->Surface-Data). The data base contains a very large and heterogeneous collection of data from many different data providers. As a consequence there exists a high variation in the quality of the data. But only a superficial and formal quality check of the data is done by the staff at MDC. It was pointed out that it is not the objective of the MAP Data Centre to perform a quality control. For routine network data this is rather the task of DAQUAMAP. If a database user detects suspicious data she or he should contact the MDC rather than the data provider directly. The staff at MDC will forward the trouble report to the data provider and ask for remedy action. If a database user contacts the data provider directly, it is not assured that detected data problems will also be corrected in the MDC. Details of the procedure for error reporting will be documented by the MDC during the following weeks and will be made available on the internet.

As a preparatory work for the DAQUAMAP, Inga Groehn has performed a “data availability check” in January 2002. For each station the mean value of the SOP for station pressure, mean sea level pressure, station temperature and dew point was calculated. Based on these results, a “gross error test” revealed that e.g. for a couple of stations geopotential heights are stored in the mean sea level pressure field of the data base. Further on, a “number-of-measurements-“ and a “double-datasets“-test were performed. There are some stations which have only very few measurement data in the data base. In the meantime most of the errors have already been solved including a reload of GTS data from the MARS archive at ECMWF. Important to mention is that now all data of the SOP are in one single data base table which was not the case before.

A still open task of WGROUND is that the data providers check whether all data they delivered to the MDC are stored correctly in the MAP database. This work will be carried out during the next few months as soon as the “data availability check” is redone. For this purpose it is essential that data providers apply for a MAP password from the MAP program office (/map-doc/DataAccessPolicy.htm). Reinhold Steinacker gave a short overview of the latest developments of the applied methods in DAQUAMAP and VERA 3 . A replacement for the operational finite element 2D version for scalar and vector quantities by a regular grid version was outlined.

Summary of Working Group Discussion

One important objective of WGROUND is to maintain and complete the inventory of hydro-meteorological stations in the Alpine Region. A lot of work and time have already been into the inventory of hydrometeorological stations in the Alpine Region. Nevertheless, work is still ongoing (never ending?), e.g. missing heights, duplicates,…

The suggestion was made to add information about measuring systems during SOP, e.g. for rain gauges because this would be helpful for the interpretation of the analyses.
This would be possible for the German Weather Service (DWD), Environmental Agency of the Republic of Slovenia (HMIS), and the Austrian Central Institute of Meteorology and Geodynamics (ZAMG). For Italy it is only possible for the GTS stations. For the Czech Hydrometeorological Institute (CHMI) and for MeteoSwiss it is easy feasible. For the HZB 2 (Austria) the measurement systems are already known. As nobody from France attended this workshop it was not possible to make a statement for the French Weather Service.

Another topic was the quality control of rain gauges and how to mark suspicious data. There was agreement that it would be very valuable to have more information about the checking and correction practices. Before contacting the data providers again, it should be checked out, how much of this information is already available with other projects (e.g. GPCC).

It was part of the objectives of this workshop to discuss the future of WGROUND. The participants agreed that it will be helpful also in the future to have a platform to exchange experience and methods for quality control. On the WGROUND-Homepage there is an (incomplete) overview of all different quality control checks of the members (http://www.univie.ac.at/IMG-Wien/daquamap/qualres.htm)
It was recognized, that the results and experiences of this working group might be also helpful for future activities or projects. (e.g. MAC 4 , UNIDART 5 , ECSN 6 , …). For this purpose a representative of the WGROUND should act as a rapporteur between the members of WGROUND and the members of e.g. ECSN. It was pointed out that it is not necessary that all institutions participating in WGROUND are members of ECSN or EUMETNET 7 .

The project DAQUAMAP will end 2002. The final results will be:
A project DAQUAMAP II was created in order to correct the dry bias in the humidity measurements of the radiosoundings performed during the SOP. In the next weeks a more detailed report of the workshop will be put on the WGROUND-Homepage http://www.univie.ac.at/IMG-Wien/daquamap/wgroundmain.html.


1 The data set of non-GTS surface hourly gathered during the MAP field phase
2 Hydrographisches Zentralbüro, Austria
3 Vienna Enhanced Resolution Analysis: http://www.univie.ac.at/IMG-Wien/vera/
4 Mesoscale Alpine Climate
5 A Uniform Data Request Interface
6 European Climate Support Network
7 The network of European Meteorological Services




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