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Better Air Quality for Beijing

Researchers at Jülich hot on the trail of air pollution in China

[27. Juni 2006]

Jülich, 26 July 2006 - Jülich atmospheric researchers set off for China at the end of June in order to carry out two large measurement campaigns on air quality this summer. Together with Chinese colleagues and teams of scientists from around the world, they are investigating the most important causes of air pollution in the highly congested areas around Beijing and in the Pearl River Delta. An important goal: better air quality for the Olympic Games 2008 in Beijing.

The economy is booming in China's urban agglomerations, industrialisation and the transport sector are rapidly growing. This leads to an undesired side effect: air pollution is also dramatically increasing. For example, the lower layer of the atmosphere, the troposphere, over China contained 50 % more nitrogen dioxide in 2002 than it did in 1996. "The Chinese are have a passionate interest in ascertaining what individual pollutants are present in the atmosphere and what photochemical processes are occurring", explains Prof. Andreas Wahner, Director at the Institute of Chemistry and Dynamics of the Geosphere at Research Centre Jülich, shortly before he left for China. Under the influence of sunlight, exhaust gases from cars and industry can be turned into heavily polluted substances - for example, ozone, which is often talked about in this country as "summer smog". On the other hand, the concentration of what are known as hydroxyl radicals is interestingbecause they break down many pollutant gases and are therefore also referred to as "atmospheric detergents".

Researchers from Peking University, who are supervising the studies, are more than happy to rely upon the expertise of scientists at Jülich. "The fact that Research Centre Jülich has been maintaining close contact with Chinese universities for years is one of the reasons for this", says Andreas Wahner. Three PhD students from Peking University and Jiatong University in Shanghai, all of whom conducted a large part of their PhDs at Jülich, are also involved in the measurement campaigns and are thereby putting the know-how they gained to use in their native country. "Another factor is that virtually no other institute is in a position to measure different trace gases in the atmosphere in such a comprehensive manner as we are. Above all, Research Centre Jülich is a global pioneer in the determination of free radicals."

The Jülich scientists will collect data on the Pearl River Delta from 3 - 30 July. For example, they will determine the different aldehydes, look at how heavily trace gases decompose photochemically and measure the concentration of short-lived free radicals. The findings could be of important significance far beyond China. "There are indications that the enormous and increasing emissions of atmospheric pollutants in China could be causing photochemical by-products, such as ozone and aerosols, to be affecting the climate and air quality of the entire northern hemisphere. This could also lead to an increase in the ozone concentration in Europe, for example", emphasizes Andreas Wahner.

A second measurement campaign has been planned for the greater Beijing area from the middle of August to the middle of September. The aim here is to precisely evaluate the existing air pollution, to identify pollution sources and to measure how different pollutants - whether it be fine dusts or nitrogen oxides - are transported in the atmosphere. "This is a highly practically oriented project", explains Wahner. "The findings will be used to provide policy guidance. The Chinese have a particular interest in seeing a decisive improvement in air quality before the Olympic Games 2008."

At the same time, the measurements taken in China will also help us to gain a better theoretical understanding of the behaviour of atmospheric pollutants. Using the values measured, the Jülich researchers will simulate the exact conditions over Beijing and the Pearl River Delta in the SAPHIR atmosphere simulation chamber at Jülich. They will then be able to ascertain whether current theories on the behaviour of atmospheric pollutants are correct or whether they must be modified. The better these models, the more accurate their predictions on what regional and global climate impacts are to be expected and on what measures both make sense and are necessary if the air is to be clean once again.


The preparations for the campaign in motion: the arrival of the Jülich measuring instruments in Back Garden Guangzhou, 50 kilometres north west of the megacity.

Photo: Forschungszentrum Jülich


Downtown Guangzhou - source of the pollution

Press Contact:

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Wissenschaftsjournalistin, Öffentlichkeitsarbeit
Forschungszentrum Jülich
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