Sandstorm Seen from Space
Over the weekend, images of a massive sand and dust storm in China were captured from space. A strong storm system swept sand and dust from the arid terrain of Inner Mongolia thousands of miles. Visibility was reduced and the air quality was poor in Beijing, Hong Kong, and Taiwan as the yellow dust rolled through the area. These spring storms are common in this part of Asia, but in the past few years the severity of the storms has increased.
Sandstorm over China on March 20, 2010. Image: NASA/Earth Observatory/Terra satellite
The above satellite image captures the dust as it wraps around in a comma shape. Mid-latitude cyclones are often associated with the giant comma-shaped clouds that reveal how air from a very wide area gets drawn in toward the low-pressure center. Scientists say desertification, or the extreme deterioration of land in arid and dry sub-humid areas due to loss of vegetation and soil moisture, is to blame for one of the worst storms in recent history. Air pollution levels reached record highs in Hong Kong and Taiwan in the wake of this weekend’s sandstorm that swept across northern China.
Beijingers stroll at Tiananmen Square during the strong sandstorm that hit on March 20. Image: Hei Jianjun/ChinaFotoPress
Desert-dust storms whip up and disperse an estimated 2.4 billion tons of soil and dried sediment throughout the Earth’s atmosphere annually. In recent years, scientists have recognized that dust storms do have a global impact.
China isn’t the only place dust storms occur. During the African dust storm season, strong winds in the Sahara Desert kick up major clouds of dusts that can move across the Atlantic Ocean in just a few days. Although some of the dust settles in the Atlantic Ocean, a large amount of it is dumped on the Caribbean Islands and southeastern U.S., which makes sunrises and sunsets redder than normal. Africa’s dust storm season runs from May to October each year.
A satellite image of a dust storm off West Africa. Image: NASA
On another note, studies have show that dust storms in Africa have a significant impact on the temperature of the Atlantic Ocean, which plays a large role in hurricane activity. In years with a lot of African dust storms, typically the Atlantic Hurricane season isn’t as active due to the cooler ocean temperatures brought on by the dust storms. High levels of airborne dust reduce the amount of sunlight that reaches the ocean, which lowers sea surface temperatures.