Massive duststorms suffocate China
Massive duststorms swept through China over the weekend, bringing record air pollution and near-zero visibility to large regions of eastern China, Hong Kong, and Taiwan. The dust will reach South Korea on Tuesday. The dust was kicked up by the strong winds of a cold front that crossed China on Saturday. The winds passed over regions of Mongolia and northwest China that have been suffering from an extended drought. Overgrazing, deforestation, and urban sprawl have combined with the drought to create large regions of new desert with loose soil that was the source of dust for this weekend's duststorm. Heavy duststorms have brought increasing amounts of dangerous particulate matter to Beijing and much of eastern China in recent years, due to the worsening desertification. Beijing issued its highest level of air pollution alert, Level 5, on Saturday.During the height of the duststorm, winds were sustained at 34 mph, gusting to 45 mph, with visibility 1 - 2 miles in heavy dust. Conditions have improved slightly to Level 4 pollution today.
Figure 1. This natural-color image from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite shows the dust storm on Saturday, March 20, 2010. Few landmarks or topographic features are recognizable beneath the dust, which covers the lower half of the image and wraps around the right-hand side in a comma shape that terminates in a large ball of dust near image center. The head of the comma marks a center of low pressure of a mid-latitude cyclone crossing the country. Image credit: NASA.
Figure 2. Drought conditions based on a 2-year deficit of precipitation, using the Standard Precipitation Index (SPI). Image credit: UK Global Drought Monitor.
Record air pollution in Hong Kong
The dust storms have brought extremely hazardous air quality to Hong Kong, which has recorded is worst air pollution levels since monitoring began in 1995. Pollution levels Monday were 12 to 14 times the amount recommended by the World Health Organization, and topped out at 400 points. An index of 100 points is considered "very high", 200 is "severe", and can lead to coughing, phlegm and sore throats. The previous record highest pollution level was 202, set in July 2008.
I'll have a new post Wednesday or Thursday.