The Hunt for Hector

A successful start for the mission flights into Australian tropical storms

[25. November 2005]

Jülich/ Darwin 25 November 2005 - The research aircraft, Geophysica and Falcon, successfully completed their first two measurement flights into the violent thunderclouds in North Australia. In the first few weeks of the international measurement campaign, SCOUT - 03, the scientists have already managed to gather important scientific data on the transport of trace gases into the upper atmosphere. Climate experts from Research Centre Jülich are coordinating the measurement campaign together with their colleagues from the German Aerospace Centre (DLR), Cambridge University and ETH Zürich (Swiss Federal Institute of Technology).

The weather was ideal: in the days prior to the first measurement flight, the Tiwi Islands off the north coast of Australia had already been hit by strong tropical thunderstorms. These thunderclouds, known as Hector, appear almost daily in the region at this time of year. "High altitude thunderstorms in the tropics are among the most important phenomena that we want to investigate in our experiment because they are capable of transporting huge air masses into the stratosphere in less than an hour ", explained Dr. Cornelius Schiller, physicist at Research Centre Jülich and coordinator of the aircraft campaign.

On 16 and 19 November, the Russian high-altitude aircraft, Geophysica, and the DLR's Falcon set off for the far-off thunderclouds reaching up to an altitude of 18 kilometres and their surroundings. Here, they measured water vapour, nitrogen oxides, ozone, cloud particles and many other trace gases. Despite the extreme conditions (moist heat on the ground, very cold temperatures at the flight altitudes) the scientific instruments and measuring probes functioned reliably. "A fantastic start to the campaign", said a delighted Cornelius Schiller. "The pilots brilliantly completed their difficult mission."

A first look at the data shows extremely low concentrations of water vapour at the transition between the troposphere and stratosphere, frequently in conjunction with very low temperatures and the appearance of cirrus clouds. The region thus works like a valve and determines how much of the greenhouse gas, water vapour, is transported into the upper atmosphere (stratosphere). Furthermore, ice clouds themselves have a strong influence on the radiative budget and thus the heat balance of the earth.

Six further flights have been planned by the scientists before the end of the measurement campaign in mid-December. With the results, they hope to explain how the ozone layer and the radiative budget in the stratosphere will change in the future.

Further information: http://www.fz-juelich.de/projects/scout/aktuelles

Geophysica shortly before its flight into the thunderclouds.

Photograph: Forschungszentrum Jülich

Last briefing between the scientists and the pilot before takeoff.

Photograph: Forschungszentrum Jülich

Contact for press:

Annette Stettien
Science Journalist
Forschungszentrum Jülich
52425 Jülich
Tel. 02461 61-2388, Fax 02461 61-4666
E-Mail: a.stettien@fz-juelich.de