爆发性气旋的合成诊断及形成机制研究
RESEARCH ON COMPOSITE DIAGNOSIS AND MECHANISMS OF EXPLOSIVE CYCLONES
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摘要: 该文对发生在太平洋和大西洋的16个爆发性气旋作了合成分折, 对强弱爆发性气旋作了对比及诊断.研究发现, 基本场上存在不少明显的差异.分析得出, 强爆发性气旋的形成与高空急流的非纬向性以及反气旋性弯曲密切相关.非纬向高空急流为爆发性气旋提供了强的辐散、斜压性、斜压不稳定场.高层强爆发性气旋前部的反气旋曲率易造成重力惯性波在能量北传时发展, 促使气旋快速加深.暖平流及非绝热加热可使反气旋曲率加强.一般情况下, 当气旋西部位涡的大值区与北部位涡的大值区叠加下沉时, 有利于气旋爆发性发展.Abstract: In this paper, 16 explosive cyclones over Atlantic and Pacific oceans are analyzed. The "weak" and "strong" explosive cyclones are diagnosed and compared. It is found that the basic fields are different at many aspects. The formation of strong explosive cyclones is related to the non-zonal upper jet of anticyclonic curvature. The jet can cause the upper divergence fields and baroclinity and baroclinic instability as well as the development of internal gravity waves northward. The warm advection and diabatic heating can increase the curvature. In general, when the larger value centers of potential vorticity move toward the centers of explosive cyclones, it is advantageous to explosive cyclones.
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Key words:
- Pacific;
- Atlantic;
- Explosive cyclone;
- Composite diagnosis;
- Non-zonal upper jet
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表 1 16个爆发性气旋的强度和爆发时及其前后地面气旋的位置
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[1] Reed J, Albright M D.A case study of explosive cyclogenesis in the eastern Pacific.Mon.Wea.Rev., 1986, 114:2297~2319. doi: 10.1175/1520-0493(1986)114<2297:ACSOEC>2.0.CO;2 [2] Robert L M, Phillip R, Smith J.A diagnosis of a model-simulated explosively developing extratropical cyclone.Mon.Wea.Rev., 1996, 124 (5):875~904. doi: 10.1175/1520-0493(1996)124<0875:ADOAMS>2.0.CO;2 [3] Kuo Y H, Simon L N.Prediction of nine explosive cyclones over the western Atlantic ocean with a regional model.Mon.Wea.Rev., 1990, 118(1):3~25. doi: 10.1175/1520-0493(1990)118<0003:PONECO>2.0.CO;2 [4] 李长青, 丁一汇.北太平洋爆发性气旋的诊断分析.气象学报, 1989, 47(2):180~190. http://www.cnki.com.cn/Article/CJFDTOTAL-QXXB198902006.htm [5] 吕筱英, 孙淑清.气旋爆发性发展过程的动力特征及能量学研究.大气科学, 1996, 20(1):90~100. http://www.cnki.com.cn/Article/CJFDTOTAL-DQXK601.010.htm [6] 徐祥德, 丁一汇, 解以扬.不同垂直加热率对爆发性气旋发展的影响.气象学报, 1996, 54 (1):73~81. http://www.cnki.com.cn/Article/CJFDTOTAL-QXXB601.007.htm [7] Sanders, Gyakum.Synoptic-dynamic climatology of the "Bomb".Mon.Wea.Rev., 1980, 108 (10):1589~1606. doi: 10.1175/1520-0493(1980)108<1589:SDCOT>2.0.CO;2 [8] Murty T S, Mcbean G A, Mckee B.Explosive cyclogenesis over the northeast Pacific ocean.Mon.Wea.Rev., 1983, 111 (5):1131~1135. doi: 10.1175/1520-0493(1983)111<1131:ECOTNP>2.0.CO;2 [9] 李崇银.非纬向基本气流的斜压不稳定.气象学报, 1984, 42:148~155. http://www.cnki.com.cn/Article/CJFDTOTAL-QXXB198402002.htm [10] Uccellini L W, Kocon P J, Petersen R A, et al.The presidents' day cyclone of 18-19 February 1979:Synoptic overview and a nalysis of the subtropoical jet stream influencing the pre-cyclogenetic period.Mon.Wea.Rev., 1984, 112:31~55. doi: 10.1175/1520-0493(1984)112<0031:TPDCOF>2.0.CO;2 [11] 周伟灿, 陈久康.非平直基流中尺度扰动的对称发展.南京气象学院学报, 1996, 19 (4):419~425. http://www.cnki.com.cn/Article/CJFDTOTAL-NJQX604.005.htm [12] 丁一汇.天气动力学中的诊断分析方法.北京:科学出版社, 1989.177~180, 114~129. [13] Uccellini L W, Keyser D.The president's day cyclone of 18-19 February 1979:Influence of upstream trough amplification and associated tropopause flooding on rapid cycogenesis.Mon.Wea.Rev., 1985, 113:962~988. doi: 10.1175/1520-0493(1985)113<0962:TPDCOF>2.0.CO;2