Workshop        Deutsche Version Deutsch

21 - 23 November 2003
DLR Oberpfaffenhofen, Germany

Summary

Programme

1. Responsibilities of the DLR
2. Lee waves
2.1. Research results
2.2. Mountain Wave Project
2.3. Forecasting waves
3. Atmospheric measurements
Vertical profile measurement using model aircraft
4. Convection
4.1. Projekt Lift
4.2. Dream "artificial thermals"
4.3. Soaring Index
4.4. Visions for soaring forecasts
5. OSTIV Handbook
6. Literature
7. Future activities
8. Any other business

 

1. The DLR's Agenda

The German Aerospace Center runs a broad research and development programme that involves both national and international co-operation. This work overlaps OSTIV's activities and goals in a symbiotic way. The DLR's invitation to hold our meeting in one of their rooms enabled an exchange of views in areas of common interest. In an introductory talk, Hans Volkert of the DLR gave an overview of the DLR's current agenda and projects in Oberpfaffenhofen.

Among many other projects, the physics and chemistry of the atmosphere is being researched with a specially equipped aircraft. This highly developed measurement platform is also made available to outside scientific teams worldwide.

2. Lee waves

2.1. Forschungsergebnisse

Following on from his introduction, Hans Volkert presented the latest research results from MAP (Mesoscale Alpine Project). The aircraft measurements for a Föhn event were compared with a high resolution numerical model calculation. What many glider pilots have more or less intuitively known was demonstrated here with a scientific precision that was impressive for the resolution with which the wave flows were included. (QJ paper to this presentation, 2.3 Mbyte).

In the second part of his lecture Hans Volkert showed measurements of wave flow in the arctic stratosphere above Scandinavia. The higher up we look, the smaller becomes the "nervousness" of the atmosphere in the wave structure. However, I believe that if in the future such systems are used by glider pilots, the nervousness of the pilots will increase with height.
http://www.pa.op.dlr.de/arctic

In connection with this fascinating exposition, Hermann Trimmel revealed the measurement results of two wave flights over the Pyranees in north Föhn, which were made during the last spring meeting of the OSTIV work group. The vertical and horizontal flows were recorded adjacent to the flight path using commercially available loggers. Knowing the positions of waves and rotors allowed a comparison with theory. For example, from the flights on the 6th of April 2003 an area of stagnation at a height of 20,000 ft, an indicator of breaking waves, could easily be recognised.

For 3D flow situations flying sailplanes could still have something to contribute towards verification of the model.

2.2. Mountain Wave Project

Rene Heise, the motor of the Mountain Wave Project, has the ambitious goal to understand waves globally. So he is very interested in wave reports and has created a wave report button for this on his web page http://www.mountain-wave-project.de

Was it a coincidence that in Argentina, during Rene's presentation, Klaus Ohlmann achieved Dr Joachim Kü's long awaited vision: a 2,000 km straight flight? Although nobody knew this at the time, even so the next programme point -

2.3. Forecasting waves

produced it as a premonition by the participants. The globally calculated wave forecast, the same as that found on Rene Heise's homepage, showed that the current situation provided good conditions for extensive waves over the Andes.

For these wave forecasts the Scorer parameter, the vertical wind components above the model orography and the resulting streamlines are calculated. The fact that the humidity is (still) not taken into consideration is important for the interpretation of the results.

3. Atmospheric measurements
Vertical profile measurements using model aircraft

Richard Heinrich reported on the deployment of a battery powered model for research projects in Nepal and Bolivia.

Specially developed battery powered models, a special method of landing with a cable braked capture net and special binoculars fitted with visual aids for aircraft recognition were outstandingly effective. Using a light (8 gm) temperature/humidity sensor, vertical profiles were recorded on a minilogger up to a record height of more than over 10,000 ft above ground! Furthermore, the measurements of this very inventive and creative group of experts were supplemented by film sequences from a small webcam mounted on the model aircraft. Naturally there is already the next vision: to achieve IFR-weather flight measurements using a mini-autopilot ...

4. Convection

4.1.Projekt LIFT

Christof Maul has taken the trouble to load the Online Competition flights onto a database and to develop a corresponding programme for selective data retrieval. 390,000 upcurrents from 2002 and 2003 are stored and can be retrieved according to date, time, height gain, climb rate etc. This project ˘LIFT÷ is continually being improved and is not yet publicly available.

The discussion showed that further filters would be of meteorological interest:
- Flight levels in relation to the time of day (important for the verification of convection)
- associate the synoptic situations with the flight days and correlate with the flight areas in a matrix
- sort by distance flown (e.g. over 500 km)
In any case, the evaluated results to date don't only show a confirmation of the well known good thermal areas ( Schwäbische Alb, Thüringer Wald etc.), but also that good thermals are to be found in lesser known areas. At the same time the limits of this data are revealed: unused thermally active areas are not covered. For this reason, glider pilots' preferences are over emphasised in these maps.

4.2. Dream "Artificial Thermals"

Markus Stracke, a long time glider pilot and inventor with numerous patents, put forward his idea for artificially influencing the weather.

With the aid of black areas convection could be so stimulated that the naturally available energy would be artificially released. So it might be possible to steer the naturally available latent potential energy of humidity somewhat nearer to the areas that urgently need it Perhaps just a dream ? or in the border areas of the tropic and subtropics even possible?

4.3. Soaring-Index

In the internet at http://www.wetter3.de there is a graphical illustration of the "Soaring Index". Also on Rene's homepage there is a link to this webpage. The experience of our group about the predictive power is: fronts and air mass borders are easily recognized; the quantitative statements do not allow any prediction of the thermal quality. So viewed is the description "Soaring Index" somewhat misleading, and might arouse too high an expectation in pilots.

4.4. Visions for soaring forecasts

The developer of Alptherm and Regtherm is looking abhead. Besides the well established forecasts of thermal strength he is planning the forecast of thermal lines. A first step are the forecasts of slope updraughts. The vision is the comprehensive forecast of the thermal density, convetion streets and thermal waves ...

5. OSTIV Handbook

After this activity coming to a complete stand still, perhaps there will still be a happy end?
Bernd gets the text as a pdf file from Martin, and the CD with the graphics from Rene. Bernd reformats the text with the latest version of Word and imports the pictures. Martin gets this end product and puts it onto the OSTIV webpage as a pdf file: goal achieved!

6. Literatur

Karl Heinz Hack Flugwetter ISBN 3-9522668-1-7
www.pilatus-aircraft.com
Robert F. Whelan Exploring the Monster ISBN 1-891118-32-3
Wind Canyon Books
Helmut Kraus Risiko Wetter ISBN 3-540-00184-0
www.springer.de
Peter Bains Topografic effects in stratified Flows ISBN 0-521-62923-3
Cambridge University Press
Roland Stull Meteorology for Scientists and Engineers ISBN 0-534-37214-7
www.brookscole.com
Frederic Vester Die Kunst vernetzt zu denken ISBN 3-540-00184-0
www.dtv.de

7. Future Activities

7.1. Next workshop

19th to 21st November 2004, again at the DLR in Oberpfaffenhofen Please note the dates!
The SSA has invited the next Meteorological Panel meeting to be held in Atlanta parallel with the SSA Convention. There was no concrete agreement from those present to take part. Hermann informed Bernald Smith , the OSTIV co-ordinator of this result.

7.2. Trainingspraktikum

There were several ideas:
- to glide cross-country with (motorisd) sailplanes to Ourzazate, and then to circle above the Atlas mountains for a while. (Dates still to be agreed with the French).
- A cross-country glide across central Europe, with the aim to of looking in on the European Championships in Lithuania (18th July to 9th August 2004).
Anyone who would like to participate should apply to Hermann, following the motto: using their own initiative.

8. Any other business

- Correction of the minutes from November 2002:
   The correct address for Marocco information is: http://volavoile.ouarzazate.free.fr

- The last edition of Technical Soaring is 2/2002. There are endeavours to eliminate this backlog

- Manfred took over writing the picture postcard in an exemplary and praiseworthy fashion.