Potential Impact of the Northeastern Atlantic-Western Mediterranean Sea Surface Temperature on the Dry-hot Wind in Henan Province
Henan Province is the main producing area of winter wheat in China,and it is also susceptible to dry-hot wind.At present,the research and forecast of dry-hot wind both are on the weather scale,it is of great signif-icance to study whether the dry-hot wind is predictable from the perspective of climate.This study analyzed the relationship between dry-hot wind days in Henan Province and preceding sea surface temperatures(SST)from 1980 to 2022,as well as potential influencing pathways,based on the dry-hot wind data from Henan Province,NCEP/NCAR reanalysis data,and SST data from the Hadley Centre.The results show that:(1)The mean annu-al dry-hot wind days in northern,northwestern and central Henan Province is more than that in other regions.The probability of dry-hot wind occurrence in the day gradually increases from south to north,and from late May to early June.The average number of dry-hot wind days in the province has a significant increasing trend.(2)There is a close correlation between the number of dry-hot wind days in Henan and the March-April SST in the northeastern Atlantic-western Mediterranean(key region)on both decadal and interannual scales.The corre-lations between the above two and the 500 hPa geopotential height during dry-hot wind periods,before and after detrending,indicate significant positive correlation areas in mid-latitude East Asia,located from northern Xinji-ang to north of the Lake Baikal,and significant negative correlation areas located from northeastern China to the Japanese archipelago,respectively.Correlations with 850 hPa wind fields show anticyclonic and cyclonic distri-butions in these significant correlation areas,respectively.There is significant correlation of northerly wind in the rear of cyclone,That is,in years with high SST in the key region in March-April,the dry-hot wind weather in Henan Province was formed under the influence of the Mongolian high pressure ridge and the East Asian trough.The correlations between the key region SST index and the circulation fields exhibits a more obvious zon-al teleconnection wave-train from the northeastern Atlantic across Eurasia to northeastern Asia in the middle-lati-tudes.(3)When the western Pacific subtropical high(WPSH)shifts southward(northward),the dry-hot wind days are more(fewer),while the high(low)SST in the key region in March-April can lead to a southward(northward)shift of the WPSH.(4)The differences of meridional mean vortex at 30°N-55°N during dry-hot wind period between years with more dry-hot wind days and years with less days,years with key region high SST index in March-April and years with low SST index,composites of 500 hPa quasi-geostrophic stream func-tion anomalies and wave activity flux during dry-hot wind period in years with high and low SST index all show that there is a zonal wave-train from the northeastern Atlantic to the western Pacific.This indicates that March-April SST in the key region can generate a similar wave train during subsequent dry-hot wind periods,propagat-ing across the Eurasian continent to northeastern Asia,with the circulation pattern in high SST years causing dry-hot wind weather in Henan Province.
万方数据
维普
