Worst is over for sandstorms
More sandstorms are likely to hit southern parts of Northwest China's Xinjiang Uygur Autonomous Region though the worst period is over.
"As for Beijing, a city under the shadow of North China's frequent sandstorms, the worst period will also to be gone with the spring," a weather official said Thursday in Beijing.
However, Zhang Guocai, director of the department of disaster reduction and prediction under China Meteorological Administration (CMA), said such disasters remain "an issue darkening the spring skyline in North China."
So far this year, China has experienced 17 sand drifting or flowing weather systems including one strong sandstorm, five average ones and 11 drifting or flowing sand phenomena, said Zhang
A sandstorm between March 26-30, the worst in this spring, delayed more than 1,200 flights including 130 flights in Beijing Capital International Airport with 20 others forced to land at airports in Tianjin, Zhengzhou, Taiyuan and Dalian.
Another duststorm between March 9 to 11, the largest this spring, swept more than 19 provinces, autonomous regions and major cities in North China and areas along the middle and lower reaches of the Yangtze River.
Reviewing the frequency, feature, intensity and impact of sandstorms in China experienced this year, Zhang said, more such disasters occurred than that in the same period of last year.
Recent studies on sunspots found that solar activity affects the ratio of sandstorms in China.
Sandstorms are likely to enter a new relatively active period around 2030 as solar activity changes, Chinese scientists predicted.
Since 2,000, there have been 67 sand drifting or sandstorm weather phenomena with an annual average frequency of 13.4, according to CMA's statistics .
So far this year, 14 such phenomena have occurred in North, Northwest and Northeast China with less intensity and duration than the previous year.
Most of them were recorded in March temperatures climbing fast in North China, up 1 C or 2 C over the average.
This led to an earlier thaw of the frozen surface layer earth there.
On top of that, prolonged dry spell days in early spring and cyclones from the Inner Mongolia caused by frequent cold air currents set the groundwork for loose surface earth and dust.
To mitigate damage, CMA started daily sandstorm forecasting in 2001, with early warnings issued through TV, radio and other media across China.
CMA can forecast sandstorms three days in advance, Zhang said.
A national early warning system for last-scale dust and sandstorms began trial operation this year.
Such forecasting system consists of 24-hour observation by ground meteorological stations and remote sensing and data transmission by satellites in space including China's Fengyun-1 meteorological satellite and the United States' NOAA satellite.
In 2002, CMA started tracking storms across the country.
This year, CMA successfully forecasted all sandstorms between January and April.