| 海表温度异常对Madden－Julian振荡的影响 |
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| 引用本文： | 巢纪平,林永辉,王斌.海表温度异常对Madden－Julian振荡的影响[J].气象学报,1996,54(3):257-271. |
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| 作者姓名： | 巢纪平 林永辉 王斌 |
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| 作者单位： | 国家海洋环境预报研究中心，中国科学院大气物理研究所 |
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| 摘 要： | 在前文［１］的基础上，进一步研究当海表温度存在经圈方向不均匀分布或偏离气候状态（距平）时，改变水分收支平衡及边界层的湿度辐合这一物理过程对Ｍａｄｄｅｎ－Ｊｕｌｉａｎ振荡的可能影响。结果表明，它对修正的Ｋｅｌｖｉｎ波和Ｒｏｓｓｂｙ波的传播性质影响不大。但当海表温度为正距平时，修正后东传Ｋｅｌｖｉｎ波振幅不稳定增长到ｅ倍的时间约减小了１４．５％，其不稳定增长率随着热源特征宽度的增加而增加，当特征宽度为２倍Ｒｏｓｓｂｙ变形半径时，不稳定增长率达极大，但当特征宽度继续增大时，其不稳定增长率又将减小。当海表温度为负距平时，修正后东传Ｋｅｌｖｉｎ波振幅不稳定增长到ｅ倍的时间约增加２０％，其不稳定增长率随着冷源特征宽度的增加而减小，当特征宽度为２倍Ｒｏｓｓｂｙ变形半径时，其不稳定增长率达极小，此后；随着特征宽度的增加其不稳定增长率随之增加，但始终小于无海表温度异常的情形。经圈尺度较小的那支修正的Ｒｏｓｓｂｙ波除波长极长的波段外，波仍是阻尼的；而经圈尺度较大的那支修正的Ｒｏｓｓｂｙ波，在短的波段内仍是不稳定增长的。
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| 关 键 词： | Madden－Julian振荡，边界层辐合，海表温度异常，色散性和不稳定性 |
| 收稿时间： | 1994/9/12 0:00:00 |
| 修稿时间： | 1995/5/18 0:00:00 |
THE INFLUENCE OF SEA-SURFACE-TEMPERATURE ANOMALY ON MADDEN-JULIAN OSCILLATION |
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| Chao Jiping,Lin Yonghui and Wang Bin.THE INFLUENCE OF SEA-SURFACE-TEMPERATURE ANOMALY ON MADDEN-JULIAN OSCILLATION[J].Acta Meteorologica Sinica,1996,54(3):257-271. |
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| Authors: | Chao Jiping Lin Yonghui and Wang Bin |
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| Institution: | National Research Center for Marine Environment Forecasts, Beijing, 100081;Institute of Atmospheric Physics, Acadmia Sinica, Beijing, 100029;Department of Meteorology, University of Hawaii, Hawaii |
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| Abstract: | Based on the previous paper, considering the non-uniformity in meridional directionand anomaly of sea surface temperature, the author continued to study the influence ofwater budget balance and moisture-convergence of boundary-layer on Madden-Julian oscillation. The results show that the influence on the propagating character of modifiedKelvin and Rossby waves is not important, but for the instability, when the sea surfacetemperature anomaly is positive, the e-folding time for the amplification of the modifiedKelvin wave reduced about 14. 5 %, the unstable growth increases with the characteristicscale of heating source.as the scale equals two times of Rossby deformation radius, theunstable growth reaches its maximum, when the scale continues to increase. the growthwill reduce. When the sea surface temperature anomaly is negative.the e-folding timefor the amplification of the modified Kelvin wave grows about 20%,the unstable growthreduces with the increase of the characteristic scale of cooling source.as the scale equalstwo times of Rossby deformation radius. the unstable growth reaches its minimum,when the scale continues to increase, the growth will increase, but it is always smallerthan the case unconsidering the sea surface temperature anomaly. For the two modifiedRossby waves,the wave with a smaller meridional scale decays except for extra-longwaves;another wave with a larger meridional scale grows in short-wave bands. |
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| Keywords: | Madden-Julian oscillation Boundary-layer convergence Sea surface temperature anomaly Dispersion and instability |
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