Wind and cold carry dust to new heights

May 6, 2013
The Taklimakan Desert is a cold, isolated sand dune desert located in the shadow of the Himalayas in China. Credit: Wikimedia Commons

(Phys.org) —Scientists at China's Lanzhou University and Pacific Northwest National Laboratory found that dust lifted from the Taklimakan Desert during a dust storm had a significant effect on the regional climate. The 2006 storm was aggravated by a cold front that pushed the dust to the highest level of the atmosphere over the northern Tibetan Plateau in China, affecting the balance of heat in the region's atmosphere. The ability to accurately model such storms will help in understanding the climatic impact of dust.

The Tibetan Plateau in China's has one of the world's largest stores of ice. As increasing ice melt over the plateau swells rivers and lakes, it also increases the amount of land in the region. The additional land mass acts as a heat pump drawing heat out of the atmosphere, increasing the intensity and duration of regional monsoons. Worldwide, monsoons provide half the Earth's population with fresh water. They also impact the world's climate via the .

The addition of dust blowing over the plateau heats the lower atmosphere, fueling the heat pump effect. In addition, when dust falls on the plateau's snow and ice, it absorbs the sun's energy and stimulates melting. In this study, results show that increasing dust over the region points to significant change the and the climate.

The researchers studied the effects of a large dust storm from the Taklimakan Desert (TD) that occurred July 21-30 in 2006. The dust swept over the northern slope of the (TP), the world's third largest ice mass. The collaborators used the and Forecasting model with chemistry (WRF-Chem) to simulate the event.

A MODIS satellite view of dust blowing across the Taklimakan Desert with the area of a cold front marked. Credit: NASA

They examined the synoptic and dust transport pathway during the dust storm and estimated the shortwave and longwave radiative forcings of TD dust transported over the TP. During a typical summer, the heat radiating from the TP and weak East Asian westerly winds ripens conditions for a dust event. During the event in 2006, the conditions were further pushed by a strong cold front system over the TD. The dust broke through the planetary boundary layer and extended to the upper troposphere over the northern slope of the TP.

This study shows that the dust radiative forcing modified the surface and TOA energy budget and atmospheric heating profile, which can modulate the stability of the atmosphere as well as surface sensible and latent heating to increase the role of the TP as a heat pump.

Researchers want to understand the worldwide climatic influence of the Taklimakan Desert, a major source of dust that ultimately travels long distances. Scientists plan to characterize the seasonal aspect of dust emissions and transport. Further, they will investigate how dust interacts with and changes clouds in its path, and how dust landing on snow changes the .

Explore further: Massive dust storm in China circled the world in 13 days: study

More information: Chen, S. et al. 2013. Modeling the transport and radiative forcing of Taklimakan dust over the Tibetan Plateau: A case study in the summer of 2006, Journal of Geophysical Research 118(2) 797-812. DOI:10.1002/jgrd.50122.

Related Stories

Soot packs a punch on Tibetan Plateau's climate

March 3, 2011

(PhysOrg.com) -- In some cases, soot – the fine, black carbon silt that is released from stoves, cars and manufacturing plants – can pack more of a climatic punch than greenhouse gases, according to a paper published ...

Saharan dust impacts West African monsoon precipitation

March 21, 2011

(PhysOrg.com) -- Africa's Saharan Desert is the largest source of mineral dust in the world, covering more than 3 million square miles and causing dust particles to blanket African skies. According to Pacific Northwest National ...

Desert dust intensifies summer rainfall in U.S. southwest

May 21, 2012

(Phys.org) -- Dust is more than something to be brushed off the furniture. Scientists at Pacific Northwest National Laboratory found that dust kicked up from the desert floor acts like a heat pump in the atmosphere, fueling ...

Recommended for you

Clues from ancient Maya reveal lasting impact on environment

September 3, 2015

Evidence from the tropical lowlands of Central America reveals how Maya activity more than 2,000 years ago not only contributed to the decline of their environment but continues to influence today's environmental conditions, ...

Ice sheets may be more resilient than thought

September 3, 2015

Sea level rise poses one of the biggest threats to human systems in a globally warming world, potentially causing trillions of dollars' worth of damages to flooded cities around the world. As surface temperatures rise, ice ...

Climate ups odds of 'grey swan' superstorms

August 31, 2015

Climate change will boost the odds up to 14-fold for extremely rare, hard-to-predict tropical cyclones for parts of Australia, the United States and Dubai by 2100, researchers said Monday.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.