Baur's Climate Statistics:
Further Information about these Time Series

How to read the diagrams

There are two different kinds of time series here: the ones which display temperature anomalies and the ones which display precipitation anomalies. In both graphics, the vertical lines are the annual anomalies and the smooth curve is an 11-year running mean. On the left, you see the unit of the anomalies, on the right some statistical figures (see below). The time scale is located at the bottom of the diagram. The seasonal anomalies are three-monthly means.

Historical Aspects

The data used in these time series were largely collected by Prof. Dr. F. Baur (1887-1977). After his death the "Institut für Meteorologie der Freien Universität Berlin" (the meteorological branch of the university of Berlin) took over the task to collect and process the data. The transformation of the data into the diagrams was performed at the "Institut für Geophysik und Meteorologie der Universität zu Köln".

In General

Prof. Dr. Baur chose the stations in a way that they are distributed homogeneously over Central Europe. For each station, the anomalies from the long-term mean are calculated and averaged over the ensemble of stations. It arises from the use of such an extended observation period, that changes in instrumentation, in the location of the observation site, as well as in the observation interval cause inhomogeneities and trends in the data set. Therefore, Prof. Dr. Baur homogenized the time series. Nonetheless, it should be kept in mind that the accuracy of the data could decrease the further back in time you look in the diagrams. This could especially affect the temperature diagrams as the average only includes 4 stations here. The general trend should not be affected, though.

What are the percentages?

The percentage values on the left side of the diagram relate to the theory of statistics: suppose the anomalies are distributed in the way Gauss proposes, then the corresponding percentage of anomalies is lower than the equivalent value on the right side.

The four temperature stations

De Bilt, Potsdam, Basel, Wien

Central European monthly temperature means in degrees C averaged for the 210-year period 1761-1970

-0.7  1.0  3.9  8.6  13.2  16.5  18.1  17.6  14.2  9.2  4.2  0.7  8.9   

The fourteen precipitation stations

Emden, Kiel, Kleve, Gütersloh, Hannover, Berlin-Dahlem, Kassel, Erfurt, Dresden, Trier, Frankfurt am Main, Bayreuth, Karlsruhe, München-Nymphenburg

Monthly mean precipitation in mm for Germany averaged for the 120-year period 1851-1970

49   42   44.1  47.2  59.3  71.7  80.3  75.7  56.9  56.4  53.6  54.5  690.7  

From 1996 onward, there will be a new station distribution for the precipitation data. The time series can be continued with the long-term average of the "old" stations anyway, because the means of the new ensemble of stations are --- from the statistical point of view --- just as representative as the old stations for precipitation anomalies in Germany.

The new stations are:

Norderney, Schleswig, Warnemünde, Hannover, Potsdam, Essen, Cottbus, Trier, Frankfurt am Main, Gera, Nürnberg, Passau, Freiburg, München

Since 2003 the station Freiburg is omitted.

Authors: Andreas Fink, Thomas Becker (August 1996)