Background

1
Investigation of Time Space Representativity
ofGAW- Measuring Site Zugspitze/
Schneefernerhaus- Introduction of the project -
Ruhr-Universität Bochum, Geogr. Institut, AG
Klimaforschung Leitung Prof. Dr. H. Fleer ?
heribert.e.fleer_at_ruhr-uni-bochum.de Bearbeitung I
. Kürbis, Dipl.-Geogr. ? ilka.k.kuerbis_at_ruhr-uni
-bochum.de Laufzeit 01.04.99 -
31.07.01 Förderung Fraunhofer Gesellschaft,
aus Mitteln des Bundesministeriums für Bildung
und Forschung
Methods Fuzzy- Logic enables the modeling of
rule based knowledge by the use of fuzzy criteria
instead of exact measurement values or threshold
values. The Method contains three steps
fuzzification, Implementation and application of
a set of rules and defuzzification of the
results. 1. Fuzzification is the relation of
filter parameters to defined criteria which each
form an own fuzzy set. By the means of
statistical methods a value for the degree of
membership is determined for each measurement
value and trajectory dataset 2. The criteria and
processes of the project are organized as a set
of rules. 3. The link of the fuzzy input with
the set of rules happens in the defuzzification.
This creates a continuous value for the possible
influence of ground based air masses in the
measured time series. Abb.
Sceme for fuzzification of a measured time series
with the example of carbon dioxide.

• Background
• Im Rahmen des Global Atmosphere Watch (GAW) -
  Projektes wird am Standort Zugspitze/
  Schneefernerhaus eine Global-station zur Messung
  von klimawirksamen und reaktiven atmosphärischen
  Spurengasen vom Umweltbundesamt aufgebaut. Dazu
  werden vom Deutschen Wetterdienst die GAW-
  Komponentenklassen meteorologische Parameter,
  atmosphärische Radioaktivität und Aerosole
  gemessen.
• Die kontinuierliche Erfassung des luftchemischen
  Hintergrunds mit dem Ziel der Früherkennung
  atmosphärischer und klimatischer Veränderung ist
  eine Kernaufgabe des GAW- Programms. Um dieser
  Aufgabe zu entsprechen, ist die Kenntnis der
  Raumzeitlichen Repräsentanz des Standortes
  Zugspitze/ Schneefernerhaus von Bedeutung.
• Project
• The determination of the time space
  representativity at the measurement site requires
  the identification of locally influenced air
  masses. This results in development and
  application of filtering functions.
• The development of filter functions using fuzzy
  logic is a central topic of this project. The
  principal idea is based on a direct pattern
  recognition of a local influence from the
  measured air chemistry time series and the
  underlying meteorological influence. Information
  about trajectory data, criteria for atmospheric
  stability, tracer substances and typical patterns
  of ground related trace substances is used for
  filtering criteria.
• Also in order to resolve the problematics ot
  threshold criteria the continuous change of
  processes is modelled in an appropriate manner
  with the fuzzy logic method in the filtering
  methods.
• The project is targeting at the development of
  filtering functions for the identification of air
  masses influenced from ground layer processes.
  The results are integrated in an database
  oriented applicaiton.