The Rossby wave train patterns forced by shallower and deeper Tibetan Plateau atmospheric heat-source in summer in a linear baroclinic model

观测结果表明,在夏季青藏高原高层大气热源(TPUHS)的发展和衰减阶段(高原热源由浅向深发展),北半球的环流异常表现出不同的Rossby波列型。本研究利用线性斜压模式LBM来探究深浅TPUHS的波列效应。模拟结果表明,深浅TPUHS能强迫出不同的Rossby波列型,而且波列型与观测结果相似。对应浅的TPUHS,Rossby波列型从青藏高原延伸至美国西海岸;而对应深的TPUHS,Rossby波列型从青藏高原延伸至阿拉斯加。

By using a linear baroclinic model(LBM),this study investigates the different Rossby wave train(RWT)patterns associated with the Tibetan Plateau(TP)upper-atmospheric heat source(TPUHS)that is anomalously shallower and deeper in boreal summer.Observational results indicate the different RWT patterns between the developing and decaying periods of synoptic TPUHS events,when the anomalous TPUHS develops from a relatively shallower to a deeper TP heat source.Based on the different vertical heating profiles between these two periods in observation,this study forces the LBM with prescribed TPUHS profiles to mimic a shallower and deeper summer TP heat source.The results show that the atmospheric responses to a shallower and deeper TPUHS do exhibit different RWT patterns that largely resemble those in observation.Namely,corresponding RWT pattern to a shallower TPUHS stretches from the TP to the west coast of America,while that to a deeper TPUHS extends from the TP region to Alaska.