Fog is an important indicator of weather. Long-term variations of fog and mist were studied byanalyzing the meteorological data from 743 surface weather stations in China's Mainland during 1951-2005.In climatology...Fog is an important indicator of weather. Long-term variations of fog and mist were studied byanalyzing the meteorological data from 743 surface weather stations in China's Mainland during 1951-2005.In climatology, there are more foggy days in the southeast than in the northwest China and more in thewinter half of the year than in the summer half. The decadal change of foggy days shows regional variation.Southwest China is the region with the most foggy days, and more than 20 foggy days occur in SichuanBasin in one year. Persistent heavy fog usually appears in winter and spring over the North China Plain andNortheast China Plain. Misty days are much more frequent in the provinces south of the Yangtze River thanin the regions north of it, and there is an obvious increase of misty days after the 1980s. Southwest China isthe area with the most number of misty days, and more than 100 misty days occur in Sichuan Basin in ayear.展开更多
基金Natural Science Foundation of China(U0733004,40375002,40418008,40775011)"863"Project(2006AA06A306,2006AA06A308)
文摘Fog is an important indicator of weather. Long-term variations of fog and mist were studied byanalyzing the meteorological data from 743 surface weather stations in China's Mainland during 1951-2005.In climatology, there are more foggy days in the southeast than in the northwest China and more in thewinter half of the year than in the summer half. The decadal change of foggy days shows regional variation.Southwest China is the region with the most foggy days, and more than 20 foggy days occur in SichuanBasin in one year. Persistent heavy fog usually appears in winter and spring over the North China Plain andNortheast China Plain. Misty days are much more frequent in the provinces south of the Yangtze River thanin the regions north of it, and there is an obvious increase of misty days after the 1980s. Southwest China isthe area with the most number of misty days, and more than 100 misty days occur in Sichuan Basin in ayear.
文摘夏季是深对流多发的季节,深对流在STE(Stratosphere Troposphere Exchange,对流层—平流层交换)过程中起着重要作用。对2005—2012年夏季我国及周边地区的深对流统计发现,2009年深对流发生的次数较少,2010年深对流发生的次数较多。通过拉格朗日输送模式对2009年和2010年夏季的大气运动状态进行模拟并统计分析,发现30°N以南和以北的地区具有明显不同的平流层—对流层交换特征,30°N以北我国及周边地区TST(Troposphere to Stratosphere Transport,对流层向平流层输送)和STT(Stratosphere to Troposphere Transport,平流层向对流层输送)较为活跃,30°N以南远没有30°N以北地区活跃,但其净输送量却大致相当。在30°N以南,6—8月净输送是对流层向平流层输送。在30°N以北,6月净输送是平流层向对流层输送,7—8月净输送是对流层向平流层输送。比较深对流出现较少的2009年夏季和深对流出现较多的2010年夏季的TST和TST-STT,发现2010年6—8月这3个月的TST和TST-STT总量都超过2009年,表明2010年夏季我国及周边地区对流层向平流层的输送和净输送都强于2009年,与深对流活动的多少可能表现出正相关。
