Hunting down clouds in a spy jet

14 February 2013

Two of the most important factors influencing climate events are still a mystery: The clouds and the aerosols in the Earth's upper atmosphere. Professor Dr. Stephan Borrmann is tracking them both down. A new, large-scale project is ready to start in the skies above India. The European Union is providing EUR 2.75 million in financial support.
 

Professor Dr. Stephan Borrmann's main concern at present is the switch to the Bachelor's and Master's degree system. He is in the process of reconfiguring his lectures. "Everything else has more or less to be done on the side," says the meteorologist.

However, this "everything else" is about to get a lot more attention. A complex, five-year research project is in the offing. The professor of the Institute of Atmospheric Physics at Johannes Gutenberg University Mainz (JGU) and director at the Max Planck Institute for Chemistry in Mainz has just received an ERC Advanced Grant, which, with a value of EUR 2.75 million, is the highest endowed award given to individual researchers by the European Union.

Measurements at altitudes of 21 kilometers

Borrmann and his team have been visiting the upper Earth atmosphere for years to examine the composition of clouds and aerosols at altitudes in the region of 14 to 21 kilometers. Now they are going to India. The new project has the somewhat unwieldy title "In situ experiments on the chemical composition of high altitude aerosols and clouds in the tropical upper troposphere and lower stratosphere," abbreviated to EXCATRO.

Clouds and aerosols are among the most important factors that determine climatic events. "But they have only been measured sporadically," explains Borrmann. "Of course, climate models do take clouds into account but only in a highly simplified form. If this is to be changed, we need to do the necessary research."

And for this purpose, the researchers are using a former Russian spy plane, the Geophysica, which can reach altitudes of up to 21 kilometers. "There are only three such planes in the world that can be used for this type of research flight." Each flight costs EUR 4 million.

Better instruments needed

"It is difficult to take measurements up there," says Borrmann. Nevertheless, in situ measurements are absolutely essential. "The cloud particles cannot be brought back to the ground, as they vaporize at temperatures above minus 85 degrees Celsius. Up there it is 90 degrees Celsius." So the Geophysica uses the collection system in its nose and the instruments in the wings to capture air flows in the stratosphere and troposphere, which are instantly analyzed.

The Americans already began conducting research in this area in the 1980s. In the early 1990s, Mainz native Borrmann participated in research work as a postdoc at the American National Center for Atmospheric Research (NCAR) in Boulder, Colorado. "When I got back to Europe, it was starting here as well." His experience meant that Borrmann was frequently in demand. "And a chair in cloud physics had just been established in Mainz." Everything fell into place and the meteorologist returned to his home city in 2000. "Pure coincidence," he asserts.

The next aim was to catch up with the Americans. "Although we now have the better airplane, the Americans still have the better instruments," says Borrmann. The meteorologist will use the EUR 2.75 million from the Advanced Grant to rectify this and develop new instruments.

Important players in the climate system

But what is so important about taking measurements over India? "Clouds are vital players in our climate system as are the tropical regions. The powerful solar radiation in the tropics produces the highest energy input in the atmosphere. And the location of the greatest input is also the most sensitive."

It has become clear that human activity has had and is continuing to have an effect on our climate. However, almost no measurements have been made over Africa and India up to now. The goal is to answer important questions. Aerosols also occur naturally. Deserts, for example, release particles into the atmosphere. But which aerosols have been produced by humankind? When fossil fuels and biomass go up in smoke, the products of combustion have a tendency to hang around – and that quite literally.

Unfortunately it is not at all easy to determine which aerosols are man-made and which are not. "Fresh soot is easy to identify," says Borrmann, giving an example. "But after a few days it will be coated in a layer of sulfuric acid and various organic materials." It is then difficult to determine its source.

The engine room boys of climate research

Borrmann's project ultimately touches on many themes. It is concerned with climate change and the hole in the ozone layer but also the daily weather forecast. "Our models are constantly improving," says the meteorologist. And when he looks beyond the confines of his own discipline and compares his efforts to those of economic forecasts, he can state with confidence: "We are much more accurate. It is no longer all that difficult to simulate the effects of El Niño and the hole in the ozone layer. But what's happening in India?" What are the effects of the developments occurring there?

Due to his research, Borrmann has a natural tendency to contemplate how mankind treats the planet. "It took millions of years to produce fossil fuels that we are going to burn up in 100 or 200 years." However, he does not think his primary role as a researcher is to admonish others. "We are the engine room boys on board the 'climate research' ship. We're not up there on the bridge telling people that Hamburg will be sinking beneath the waves by such and such a year."

But what good would a ship's bridge be without an engine room? Borrmann and his colleagues will be beginning their work on the EXCATRO project this year. Their goal is to develop new equipment for the engine room and then they willll be flying high again. There are still plenty of mysteries up there in the clouds.