IMP Institute of Meteorology and Physics
University of Natural Resources and Life Sciences, Vienna, Austria
Environmental Meteorology Group

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Project: Atmospheric trajectory calculation

Staff: Petra Seibert, Andreas Stohl, Gerhard Wotawa

Kathrin Baumann (ZAMG Wien)
and others


Trajectories have since long been a focus of the environmental meteorology group. They are an important tool in environmental meteorology and have been used in many of the group's research projects.

A number of studies have been carried out on the methods of trajectoy calculation and the uncertainties associated with them. One study investigated numerical aspects, while other studies looked at the errors caused by different interpolation methods for the wind fields. Different methods to compute trajectories were compared based on conservative meteorological quantities used as tracers, e.g. potential vorticity.

The trajectory model FLEXTRA has been developed by the group. It is a very efficient, accurate and flexible model which can easily be adapted to input fields from different sources and can calculated different kinds of trajectories (e.g., 3-dimensional, isentropic, or boundary-layer trajectories). It is freely available for noncommercial research applications. For more details, see Andreas Stohl's research home page. If you are a FLEXTRA user and if you have a user account at ECMWF, we can provide you with a programme to extract FLEXTRA input from the ECMWF MARS archive.


Seibert P. (1993): Convergence and accuracy of numerical schemes for trajectory calculations. J. Appl. Meteor., 32, 558-566.

Stohl, A., and G. Wotawa (1994): FLEXTRA - Version 1.0. Modelldokumentation, 47 p. Internal report. Institute of Meteorology and Physis, Univ. of Vienna. Download as Winword file (146 kB).

Stohl A., G. Wotawa, P. Seibert, H. Kromp-Kolb (1995): Interpolation errors in wind fields as a function of spatial and temporal resolution and their impact on different types of kinematic trajectories. J. Appl. Meteor., 34, 2149-2165.

Stohl A., und G. Wotawa (1995): A method for computing single trajectories representing boundary layer transport. Atmos.Environ. 29, 3235-3239.

Stohl, A., K. Baumann, G. Wotawa, M. Langer, B. Neininger, M. Piringer, and H. Formayer (1997): Diagnostic downscaling of large scale wind fields to compute local scale trajectories. J. Appl. Meteor. 36, 931-942.

Baumann, K., and A. Stohl (1997): Validation of a long-range trajectory model using gas balloon tracks from the Gordon Bennett Cup 95. J. Appl. Meteor. 36, 711-720.

Stohl, A., and P. Seibert (1998): Accuracy of trajectories as determined from the conservation of meteorological tracers. Q. J. R. Meteor. Soc. , 125, 1465-1484 (No. 549, July 1998 Part A),.

This list contains only work in which present working group members were involved, or work by Andreas Stohl before he went to Munich. He continues to work on the topic and you may wish to look into A. Stohl's publication list for additional references. An especially interesting paper is:

Stohl A. (1998): Computation, accuracy and applications of trajectories - a review and bibliography. Atmos. Environ., 32(6), 947-966.

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last update: 31 July 1998 by P. Seibert | URL of this page: