Air pollution is reducing the amount of rain in China

Aug 31, 2009

Air pollution in eastern China during the last 50 years has led to a reduction in the amount of light rainfall of almost a quarter. This is revealed by an international study conducted with support from the University of Gothenburg, Sweden. There is a risk that the consequences will be increased drought, reduced harvests and poorer public health.

China’s dramatic growth has also brought about an increase in environmental problems. At the same time as the population has more than doubled during the last century, emissions into the atmosphere have increased by 800 percent. The has been particularly pronounced in eastern , where most of the people live and where the emissions are greatest: it does not rain in the same way as it did before.

In some parts of eastern China the number of days with rain has diminished by 23 percent in 50 years. The consequences are increased drought and poorer harvests. A team of climate researchers from the USA, China and Sweden - including Deliang Chen, Professor of Physical Meteorology in the Department of Earth Sciences, University of Gothenburg - has now studied the problem and demonstrated that the reduced amounts of rainfall have a direct connection with high concentrations of air pollution. 

According to the researchers, the failure of rain to appear has a direct link to the concentrations of in the atmosphere. Researchers have long been aware that aerosol, which consists of small particles surrounded by gas and water, has the capacity to ”gather” raindrops around it in clouds. However, in the current study the researchers discovered that where there was a high aerosol content, the raindrops were considerably smaller - in some cases only half the normal size. As it is more difficult for smaller raindrops to coalesce into rain clouds that can release rain, the thus leads to the reduction in light (under 10 millimetres). 

The study, which is based on data from 162 weather stations, is published in the Journal of Geophysical Research

More information: Qian, Y., D. Gong, J. Fan, L. R. Leung, R. Bennartz, D. Chen, and W. Wang (2009), Heavy pollution suppresses light in China: Observations and modeling, J. Geophys. Res., 114, D00K02, doi:10.1029/2008JD011575

Provided by University of Gothenburg (news : web)

Explore further: NASA's HS3 looks Hurricane Edouard in the eye

add to favorites email to friend print save as pdf

Related Stories

Dirty air brings rain -- then again, maybe not

Sep 08, 2008

An international team of scientists, headed by Prof. Daniel Rosenfeld of the Institute of Earth Sciences at the Hebrew University of Jerusalem, has come up with a surprising finding to the disputed issue of ...

Aerosol pollution slows down winds and reduces rainfall

Jan 22, 2007

The winds that blow near the surface of the Earth have two beneficial effects: They provide a renewable source of clean energy and they evaporate water, helping rain clouds to build up. But aerosolized particles created from ...

China has its worst spell of acid rain

Sep 22, 2006

China had its worst spell of acid rain in August with Beijing among the hardest hit, the China Meteorological Administration said Friday.

Study says Chinese air quality standards not yet met

May 13, 2008

With the Olympic Games in sight, the Chinese Government is committed to improving the air quality in Beijing, and has had measures in place since 1998 which have already made a difference. However, there is still some way ...

Recommended for you

NASA's HS3 looks Hurricane Edouard in the eye

9 hours ago

NASA and NOAA scientists participating in NASA's Hurricane and Severe Storms Sentinel (HS3) mission used their expert skills, combined with a bit of serendipity on Sept. 17, 2014, to guide the remotely piloted ...

Tropical Storm Rachel dwarfed by developing system 90E

14 hours ago

Tropical Storm Rachel is spinning down west of Mexico's Baja California, and another tropical low pressure area developing off the coast of southwestern Mexico dwarfs the tropical storm. NOAA's GOES-West ...

NASA ocean data shows 'climate dance' of plankton

17 hours ago

The greens and blues of the ocean color from NASA satellite data have provided new insights into how climate and ecosystem processes affect the growth cycles of phytoplankton—microscopic aquatic plants ...

Glaciers in the grand canyon of Mars?

18 hours ago

For decades, planetary geologists have speculated that glaciers might once have crept through Valles Marineris, the 2000-mile-long chasm that constitutes the Grand Canyon of Mars. Using satellite images, ...

NASA support key to glacier mapping efforts

19 hours ago

Thanks in part to support from NASA and the National Science Foundation, scientists have produced the first-ever detailed maps of bedrock beneath glaciers in Greenland and Antarctica. This new data will help ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

NeilFarbstein
2.3 / 5 (3) Aug 31, 2009
its the greenhouse effect