Abstract:
By using the monthly averaged temperatures(1951~1995) at observatories in 6provinces in Southern China,the characteristics of chilling damage in spring in the regions are studied.Seven chilling damage years including 1957,1968,1969,1970,1984,1985 and 1988 in spring are recognized and the most serious chilling damage years are 1968 and 1988. The severe chilling damages happen mainly in March or April. And the severe chillingdamages appear most frequently in southern part of the south of Yangtze River valley. The inter-annual variation of chilling damage in spring in Southern China is characterized by phase and extensive space synchronization. The southern spring chilling damage occurs most frequently in the 80's,more in the 50's,much less in 60's and 70's,and hardly happen in the earlier 90's. The differences of some physical components including the atmospheric index,anomalous height at 500 hPa geopotential in Northern Hemisphere and anomalous SSTs for Spring(February~April),between typical spring chilling years and typical spring warm years are obvious. Especially,
t-test shows that significance of the Asia polar vortex,zonalcirculation index,the most northern extension edge of subtropical high of Northern WestPacific and the warm pool of Pacific Ocean,are at 95%(90%).