日韩午夜精品视频,欧美私密网站,国产一区二区三区四区,国产主播一区二区三区四区

China's northwestern, northern and northeastern areas have experienced the most evident climate warming in the country for the past century, which, in turn, has worsened the aridity in northern China.

On this year's World Meteorological Day, which falls on March 23, Chinese meteorologists held in-depth discussions on the theme of "Our Future Climate."

According to professor Ding Yihui, special advisor on climate change with the China Meteorological Administration (CMA), the climate warmed most distinctly in the country's northwestern, northern and northeastern areas. Shaanxi and Gansu provinces as well as Ningxia Hui Autonomous Region and Xinjiang Uygur Autonomous Region have a higher warming intensity than the national average.

However, this climate warming has shown no signs in areas to the south of the Yangtze River, Ding said.

Zhang Jiacheng, former vice president of the Academy of Meteorology, said that a lessening temperature difference between China's northern and southern areas will weaken airflow and thus reduce the amount of vapor carried from oceans to the land.

Meanwhile, the temperature rise will intensify evaporation. Therefore, it is speculated that the populous middle-latitude areas may experience increasingly dry weather, Zhang added.

North China entered an arid period in 1956. Though interrupted by several years with comparatively rich rainfalls, the warming and drying trend has not been changed.

Zhu Changhan, chief researcher on climactic effects with the National Climate Center, noted that if no effective response measures are taken, the trend will lead local areas into a vicious circle with more serious droughts and a shortage of water resources.

According to the CMA's statistics, though rainy and snowy weather have swept across most of China from last winter to this spring, the precipitation in the central and southern region of north China as well as the southwestern areas in northeast China is lower than the national average by 50 to 90 percent. Some parts in China's northern and northeastern areas have seen droughts of various degrees.

Ding Yihui also pointed out that a warm winter is an obvious feature in China's climate change.

Beginning in 1985, the whole country experienced warm winters for 16 successive years, among which the winter of 1998 was warmest, followed by the winter of 2001.

Meteorologists said a warm winter should be partially responsible for the occurrence of the decade's strongest sandstorm that overwhelmed half of China's territory in the spring of 2002.

Research results show that China's temperature has increased by0.4 to 0.5 degree Celsius in the last century, slightly lower than the global average of 0.6 degree Celsius. The 1990s was one of the country's warmest periods in the past 100 years.

(Xinhua News Agency March 23, 2003)