Study on Processes of Persistent Rainy or Snowy Events in Ningxia
Using daily precipitation and total cloud amount data from main weather station of Ningxia province since 1961,we defined the concept of persistent rainy or snowy events and analyzed their distribution characteristics and the evolution rule in recent 50 years.The frequency of persistent rainy or snowy events in Ningxia declined since 1961,especially the persistent rainy or snowy events lasting 5 to 7 days.The frequency of persistent rainy or snowy events in winter rose,and the variation degree of persistent rainy or snowy events in winter increased obviously in recent years,while the frequencies of persistent rainy or snowy events in the other seasons declined,especially in spring.The frequency of persistent rainy or snowy events was still few in the 21st century,but it obviously increased,especially in autumn and winter,compared to 1990s.The frequency of the persistent rainy or snowy events lasting more than 8 days increased obviously,and the annual,autumn and winter frequency was the most in different decades since 1961.In recent 50 years,the precipitation and lasting time of persistent rainy or snowy events decreased,but it obviously increased since 2001.The total times and the process precipitation remarkably increased in 21st century compared to 1980s and 1990s.The total frequency of persistent rainy or snowy events lasting above 10 days and the proportion of process precipitation between 50 to 99.9 mm in 21st century were the most.The reduction of frequency of persistent rainy events led to the reduction of precipitation and the increase of drought.
persistent rainy or snowy eventslasting timeprecipitationdrought
NETL
NSTL
万方数据
维普
