A Climatology of the Surface Heat Source on the Tibetan Plateau in Summer and Its Impacts on the Formation of the Tibetan Plateau Vortex
A Climatology of the Surface Heat Source on the Tibetan Plateau in Summer and Its Impacts on the Formation of the Tibetan Plateau Vortex
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发表时间：
2016
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通讯作者：
Liu Guopin
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作者：
Liu Guopin
利用NCEP/DOE(国家环境预报中心/能源部)青藏高原地面感热和潜热通量再分析资料和MICAPS(气象信息综合分析处理系统)天气图识别的青藏高原低涡资料，研究了近30年(1981-2010年)夏季青藏高原地面加热和低涡发生频率的气候特征，分析了青藏高原地面加热与TPV统计的时间相关性及其物理成因。结果表明：夏季TP地面感热通量的气候平均值为58Wm-2，近30年总体呈弱下降趋势。S在1980年初和21世纪头十年的大部分时间里有明显的上升趋势，但之间有波动下降的趋势。地面加热呈现准三年周期振荡，1996年前后开始出现气候突变。夏季地表潜热通量的气候平均值为62Wm-2，近30年来呈波动变化，并有增加的趋势。地面潜热呈现准四年周期振荡，2004年前后开始急剧增加。夏季地表热源的气候平均值为120Wm-2，地面感热和潜热对夏季TP地表热源的贡献相当。地表热源总体呈温和减弱趋势，1990年S至1980年S为强相，21世纪前6年为明显弱相，之后又变强。地表热源在1997年前后表现出三年的周期振荡和由强变弱的突变。根据MICAPS天气图的识别，近30年来夏季热带气旋的线性频率呈一定程度的下降，较高的频率主要集中在1980年的S至1990年的S。夏季热带气旋的发生频率呈现出7年的周期振荡，并在1998年前后出现突变。同期热带气旋的产生频率与感热呈高度正相关，与潜热呈弱负相关，但与TP上的地表热源相比，仍呈显著正相关。因此，在气候尺度上，TP地面加热，特别是地面感热的较强周期对应于TPVs的有利形成。从气候统计的时间相关性角度，揭示了TP地面加热对热带气旋和对流活动的促进作用。
Based on NCEP/DOE(National Centers for Environmental Prediction/Department of Energy) reanalysis data of surface sensible heat and latent heat fluxes on the Tibetan Plateau(TP) and datasets of the Tibetan Plateau Vortex(TPV) recognized from MICAPS(Meteorological Information Comprehensive Analysis and Process System) weather maps, this paper studies the near 30-year(1981–2010) climatological characteristics of surface heating and generating frequency of TPVs over the TP in summer, and analyzes the temporal correlation between the TP surface heating and the TPV statistics and its physical cause. The following results are obtained: The climatic average of TP surface sensible heat fluxes in summer is 58 W m-2, showing an overall weak decreasing trend in the near 30-year period. An increasing trend is apparent in the early 1980 s and most of the first decade of the 21 st century, but a fluctuating decline between. Surface heating shows a quasi-three-year periodic oscillation, and an abrupt climate change starts around 1996. The climatic average of surface latent heat fluxes in summer is 62 W m-2, showing fluctuating changes accompanied by an increasing trend over the near 30-year period. The surface latent heat shows a quasi-four-year periodic oscillation, with an abrupt increase beginning around 2004. The climatic average of the surface heat source in summer is 120 W m-2; sensible heat and latent heat on the ground contributes the same to the surface heat source over the TP in summer. The surface heat source shows a modest weakening trend overall, with a strong phase between the 1990 s and 1980 s, an obvious weak phase in the first six years of the 21 st century, and then becomes strong again. The surface heat source shows a three-year periodic oscillation and an abrupt change from strong to weak around 1997. Based on identification using the MICAPS weather maps, the linear frequency of summer TPVs over the near 30-year period showed a certain degree of decline, with a higher frequency mainly concentrated in the 1980 s to 1990 s. The generating frequency of TPVs shows a 7-year periodic oscillation, and features an abrupt change around 1998. The generating frequency of TPVs over the same period is highly positively correlated to sensible heat but weakly negatively correlated to latent heat, but compared with the surface heat source over the TP, is still a significant positive correlation. On the climate scale, therefore, stronger periods of TP surface heating, especially surface sensible heating, correspond to the favorable formation of TPVs. From the perspective of the temporal correlation of climate statistics, this study reveals important impacts of the TP surface heating on promoting TPVs and convective activity.