| 摘要: |
| 本文运用Hoskins和Simmons的波流相互作用原理,分析1981—1982年冬、夏季对流层高层200hPa上纬向非对称基本流(时间平均流)的正压不稳定和30—50天振荡的关系。指出西风急流的出口区是30—50天振荡动能和基本流以及低频振荡相互作用的最强的区域,且低频振荡从基本流的正压不稳定中获得能量,并在一周内得到充分的发展。 另外还表明,由于基本流的正压不稳定作用,使40°N的亚洲大陆和沿海及45°N的大西洋中部附近成为夏季30—50天振荡的主要能源区,使30°N的中太平洋和40°N的北美东部附近成为冬季30—50天振荡的主要能源区。 |
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| 基金项目:国家自然科学基金资助 |
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| A DIAGNOSIS OF ZONALLY ASYMMETRIC BAROTROPY OF BASIC FLOW INFLUENCE ON 30-50 DAY OSCILLATION |
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Xu Jianjun1, Lin Chunyu2
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1.Nanjing Institute of Meteorology;2.Department of Atmoepheric Science Nanjing University
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| Abstract: |
| This paper applies the Hoskin's and Simmon's wave-flow interaction principle to analise the relationship between the zonally asymmetric barotropic instability in basic flows for 200 hPa and the 30 -50 day periodic oscillation from 1981 to 1982.It is pointed out that the jet stream exit is the strongest field of interaction between kinetic energy of 30-50 day oscillation, basic flows and low-frequency oscillation.The low-frequency oscillation acquires energy from basic flows and develops fully within a week.The Asian continent (40°N) and the middle part of the Atlantic (45°N) is a major energy source for 30-50 day summer oscillation, while the middle part of the Pacific (30°N) and Northern America coast (40°N) is a major energy source for 30-50 day winter oscillation. |
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