热带海温对珠江三角洲春季灰霾日数年际变化的影响OA北大核心CSTPCD

The present study analyzed the impact of sea surface temperature(SST)on the interannual variability of spring haze in the Pearl River Delta(SHDPRD)by using daily ground-based observational data from 86 stations of the Guangdong Meteorological Service,along with reanalysis data from the National Centers for Environmental Prediction and the Extended Reconstructed Sea Surface Temperature dataset from the National Centers for Environmental Information for the period 1979-2018.The results show that the SST of the Southeast Pacific(ISSTSEP)played a leading role in the modulation of SHDPRD.Negative(positive)ISSTSEP anomalies stimulated the eastward propagation of cold(warm)Kelvin waves through the Gill forced response,causing Ekman convergence(divergence)in the Western Pacific Ocean and inducing abnormal cyclonic(anticyclonic)circulation.It was closely linked with the positive(negative)Eurasian-Asian teleconnection pattern,which resulted in the temperature and precipitation enhancement(reduction)in the Pearl River Delta and provided favorable local meteorological conditions that were conducive(not conducive)to haze occurrence.The main meteorological conditions playing a role in modulating the SHDPRD were precipitation,vertical velocity,and convective stability,followed by boundary layer thickness and low-level northeasterly winds,and finally moisture.The El Niño-Southern Oscillation in spring had a limited modulating effect on the variation of haze days in the PRD region.During El Niño(La Niña)springs,the fewer(more)haze occurrences were related to increased(decreased)moisture,intensified vertical upward(downward)movement,and enhanced(reduced)precipitation.