热带气象学报2017，Vol.33Issue(2)：155-166,12.DOI:10.16032/j.issn.1004-4965.2017.02.002
2010年华南前汛期持续性降水异常与准双周振荡
PERSISTENT PRECIPITATION ANOMALIES AND QUASI-BIWEEKLY OSCILLATION DURING THE ANNUALLY FIRST RAINY SEASON OVER SOUTH CHINA IN 2010
摘要
Abstract
Based on the in-situ daily precipitation from Chinese Meteorological Administration(CMA) and the National Centers for Environmental Prediction-Department of Energy(NCEP-DOE) daily reanalysis data,the low-frequency characteristics of precipitation anomalies and the impact of atmospheric circulation during the rainy seasons of South China in 2010 are investigated.The results show that the precipitation anomalies during this period have obvious low-frequency characteristics.Specifically,the annually first rainy season is controlled by a 10～20-day oscillation (quasi-biweekly oscillation),while the annually second rainy season is controlled by a 20 ～50-day oscillation (intraseasonal oscillation).With focus on the quasi-biweekly oscillation,the relationship between the persistent precipitation anomalies and the atmospheric low-frequency oscillation at mid-high latitude and tropical zone during the annually first season is discussed.The low-frequency circulation at the mid-high latitude can influence the low-frequency circulation over South China by the dispersion of Rossby wave along the low-frequency wave train.The analysis of wave activity flux indicates that the wave energy originated from West Siberia disperses toward the eastern China along the low-frequency teleconnection wave train which stretches across the Eurasian continent,leading to the strengthening of the disturbance over eastern China and the precipitation anomalies by changing the low-frequency circulation and vertical movement over South China.The quasi-biweekly oscillation over the tropical eastern Indian Ocean (IO) is another low-frequency origin influencing the annually first season of South China.When the convection over the eastern equatorial IO is strong (inhibited),there are strong ascending (descending) movements in this region accompanied with convergence (divergence) at lower layer and convergence (divergence) at upper atmosphere.At the same time,descending (ascending) wind prevails over South China,suppressing (promoting) the precipitation.The superposition of low-frequency signals from mid-high and low latitude,along with the transportation of anomalous moisture,determined the low-frequency variations of circulation anomalies over South China,causing the low-frequency precipitation anomalies and favoring the persistent rain anomalies.关键词
华南前汛期/降水异常/准双周振荡/遥相关波列/热带低频对流活动Key words
annually first rainy season over South China/precipitation anomalies/quasi-biweekly oscillation/teleconnection wave train/low-frequency oscillation of tropical convection分类
天文与地球科学引用本文复制引用
苗芮,温敏,张人禾..2010年华南前汛期持续性降水异常与准双周振荡[J].热带气象学报,2017,33(2):155-166,12.基金项目
国家重点基础研究发展项目规划“973”(2012CB417205) （2012CB417205）
国家自然科学基金项目(41221064)中国气象科学研究院基本科研经费(2015Z001)共同资助 （41221064）
