近60年华北地区夏季降水与亚洲-太平洋涛动的联系

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关键词华北地区;夏季降水;时空特征;亚洲-太平洋涛动(APO);大气环流中图分类号:P461.2文献标志码:A 文章编号:2096-3599(2025)03-0072-12DOI:10.19513/j.cnki.hyqxxb.20240508001
AbstractBased on the daily gridded precipitation dataset (CNO5.1),NCEP/NCAR reanalysis data and HadISST monthly data,the linear regression and wavelet analysis,as well as the linear baroclinic model (LBM),are employed to examine the spatial-temporal variability of the summer precipitation in NorthChina from 1961 to 2O2O and its relationship with Asian-Pacific Oscilation (APO). The results are as follows.(1)The summer precipitation in North China exhibits aspatial pattern of higher values in the southeast and lower values in the northwest,and there is notable interannual variability.(2)The APO modulates the summer precipitation in North China by altering the East Asian atmospheric circulation.More specifically,the intensified APO correlates with a stronger South Asia high,a stronger and northward western Pacific subtropical high and an enhancement of low pressre across the Asian continent,thereby intensifying the East Asian and South Asian summer monsoons.This leads to the enhanced transfer of water vapor towards North China,fostering convergence and ultimately higher summer precipitation in North China,and vice versa.(3)The APO also modifies the sea surface temperature (SST) gradient between the eastern and western Pacific regions via wind fields,inducing an ENSO(El Nino-Southern Oscilation)-like SST anomaly in the Pacific Ocean, which,in turn,impacts the Walker circulation and indirectly modulates the summer precipitation in North China.(4) The numerical simulations employing the LBM further validate that the anomalous heat sources over the Qinghai-Tibet Plateau elicit a response in the upper tropospheric geopotential height,which fosters APO development and consequently a stronger South Asia high.Simultaneously,the middle and lower troposphere exhibits an anomalous cyclonic circulation,which bolsters the East Asian and South Asian summer monsoons,thereby enhancing the transfer of water vapor towards North China and the summer precipitation there.
Keywords North China; summer precipitation; spatial-temporal characteristics; Asian-PacificOscillation(APO);atmospheric circulation
0 引言
华北地处东亚大陆季风区北部,不仅是中国最重要的粮食生产区之一,也是中国最重要的重工业基地之一。(剩余14458字)