巢纪平,林永辉,王斌. 1996. 海表温度异常对Madden-Julian振荡的影响[J]. 气象学报, 54(3):257-271, doi:10.11676/qxxb1996.027
海表温度异常对Madden-Julian振荡的影响
THE INFLUENCE OF SEA-SURFACE-TEMPERATURE ANOMALY ON MADDEN-JULIAN OSCILLATION
投稿时间:1994-09-12  修订日期:1995-05-18
DOI:10.11676/qxxb1996.027
中文关键词:  Madden-Julian振荡  边界层辐合  海表温度异常  色散性和不稳定性
英文关键词:Madden-Julian oscillation  Boundary-layer convergence  Sea surface temperature anomaly  Dispersion and instability
基金项目:
作者单位
巢纪平 国家海洋环境预报研究中心, 北京, 100081 
林永辉 中国科学院大气物理研究所, 北京, 100029 
王斌 夏威夷大学气象系, 夏威夷 
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中文摘要:
      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。
英文摘要:
      Based on the previous paper, considering the non-uniformity in meridional direction and anomaly of sea surface temperature, the author continued to study the influence of water budget balance and moisture-convergence of boundary-layer on Madden-Julian oscillation. The results show that the influence on the propagating character of modified Kelvin and Rossby waves is not important, but for the instability. when the sea surface temperature anomaly is positive, the e-folding time for the amplification of the modified Kelvin wave reduced about 14.5%,the unstable growth increases with the characteristic scale of heating source, as the scale equals two times of Rossby deformation radius, the unstable growth reaches its maximum, when the scale continues to increase, the growth will reduce. When the sea surface temperature anomaly is negative, the e-folding time for the amplification of the modified Kelvin wave grows about 20%. the unstable growth reduces with the increase of the characteristic scale of cooling source, as the scale equals two 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 smaller than the case unconsidering the sea surface temperature anomaly. For the two modified Rossby 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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