Advanced Search
Article Contents

Some Aspects of the Characteristics of Monsoon Disturbances Using a Combined Barotropic-Baroclinic Model


doi: 10.1007/BF02657007

  • A standing Rossby wave of wavelength 30o longitude with a finite amplitude along the meridional direction is superimposed on the zonal mean component of the monsoon flow and the stability of such a flow is examined by a quasi-geostrophic barotropic, as well as by a quasi-geostrophic combined barotropic and baroclinic model on a beta plane centered at 18oN latitude. It is found that the growth of synoptic scale disturbance increases with the amplitude of the meridional wind. The barotropic stability analysis at 700 hPa pressure level shows that there is a critical value (Umax=11m/s) of the maximum mean zonal wind below which the computed disturbance moves to the west due to the wave-wave superposition. For maximum mean zonal wind greater that 11 m / s, the westerly wind dominates and the disturbance moves to the east. In another analysis the stability of the zonally asymmetric basic flow is studied with a combined barotropic-baroclinic model where cumulus heating is included. The growth rate, intensity, horizontal scale and the westward velocity of computed disturbances reasonably agree with those of observed monsoon disturb?ances. The fastest growing mode has a horizontal wavelength of 2000 kms and the e-folding time is about 3 days, when the meridional amplitude of the Rossby wave is 4 m / s at 700 hPa pressure level. When cumulus heating is in?cluded in the analysis the intensity of geopotential perturbation at 700 hPa disturbance is -304 m2 / s2. Energy calcu?lations show that the kinetic energy of the mean zonal flow is the main source of energy for the perturbation to grow. It is also found that the contribution of the kinetic energy of the basic Rossby wave to the growth of perturbation is more in comparison to the available potential energy.
  • [1] LI Rui, ZHANG Zuowei, WU Lixin, 2014: High-Resolution Modeling Study of the Kuroshio Path Variations South of Japan, ADVANCES IN ATMOSPHERIC SCIENCES, 31, 1233-1244.  doi: 10.1007/s00376-014-3230-4
    [2] LIU Yudi, WANG Bin, JI Zhongzhen, 2003: Research on Atmospheric Motion in Horizontal Discrete Grids, ADVANCES IN ATMOSPHERIC SCIENCES, 20, 139-148.  doi: 10.1007/BF03342058
    [3] LI Chun, SUN Jilin, 2015: Role of the Subtropical Westerly Jet Waveguide in a Southern China Heavy Rainstorm in December 2013, ADVANCES IN ATMOSPHERIC SCIENCES, 32, 601-612.  doi: 10.1007/s00376-014-4099-y
    [4] Hanying LI, Peng HU, Qiong ZHANG, Ashish SINHA, Hai CHENG, 2021: Understanding Interannual Variations of the Local Rainy Season over the Southwest Indian Ocean, ADVANCES IN ATMOSPHERIC SCIENCES, 38, 1852-1862.  doi: 10.1007/s00376-021-1065-3
    [5] Tong XIE, Liguang WU, Yecheng FENG, Jinghua YU, 2024: Alignment of Track Oscillations during Tropical Cyclone Rapid Intensification, ADVANCES IN ATMOSPHERIC SCIENCES, 41, 655-670.  doi: 10.1007/s00376-023-3073-y
    [6] Huang Ronghui, Zang Xiaoyun, Zhang Renhe, Chen Jilong, 1998: The Westerly Anomalies over the Tropical Pacific and Their Dynamical Effect on the ENSO Cycles during 1980-1994, ADVANCES IN ATMOSPHERIC SCIENCES, 15, 135-151.  doi: 10.1007/s00376-998-0035-3
    [7] WANG Yafei, Fujiyaoshi YASUSHI, Kato KURANOSHIN, 2003: A Teleconnection Pattern Related with the Development of the Okhotsk High and the Northward Progress of the Subtropical High in East Asian Summer, ADVANCES IN ATMOSPHERIC SCIENCES, 20, 237-244.  doi: 10.1007/s00376-003-0009-4
    [8] Luo Dehai, 1999: Nonlinear Three-Wave Interaction among Barotropic Rossby Waves in a Large-scale Forced Barotropic Flow, ADVANCES IN ATMOSPHERIC SCIENCES, 16, 451-466.  doi: 10.1007/s00376-999-0023-2
    [9] Yaokun LI, Jiping CHAO, Yanyan KANG, 2021: Variations in Wave Energy and Amplitudes along the Energy Dispersion Paths of Nonstationary Barotropic Rossby Waves, ADVANCES IN ATMOSPHERIC SCIENCES, 38, 49-64.  doi: 10.1007/s00376-020-0084-9
    [10] Yaokun LI, Jiping CHAO, Yanyan KANG, 2022: Variations in Amplitudes and Wave Energy along the Energy Dispersion Paths for Rossby Waves in the Quasigeostrophic Barotropic Model, ADVANCES IN ATMOSPHERIC SCIENCES, 39, 876-888.  doi: 10.1007/s00376-021-1244-2
    [11] Mu Mu, Xiang Jie, 1998: On the Evolution of Finite-amplitude Disturbance to the Barotropic and Baroclinic Quasigeostrophic Flows, ADVANCES IN ATMOSPHERIC SCIENCES, 15, 113-123.  doi: 10.1007/s00376-998-0023-7
    [12] Luo Dehai, 1998: Topographically Forced Three-Wave Quasi-Resonant and Non-Resonant Interactions among Barotropic Rossby Waves on an Infinite Beta-Plane, ADVANCES IN ATMOSPHERIC SCIENCES, 15, 83-98.  doi: 10.1007/s00376-998-0020-x
    [13] Luo Dehai, Ji Liren, 1988: ALGEBRAIC ROSSBY SOLITARY WAVE AND BLOCKING IN THE ATMOSPHERE, ADVANCES IN ATMOSPHERIC SCIENCES, 5, 445-454.  doi: 10.1007/BF02656790
    [14] Ren Shuzhan, 1991: New Approach to Study the Evolution of Rossby Wave Packet, ADVANCES IN ATMOSPHERIC SCIENCES, 8, 79-86.  doi: 10.1007/BF02657366
    [15] SHEN Xinyong, DING Yihui, ZHAO Nan, 2006: Properties and Stability of a Meso-Scale Line-Form Disturbance, ADVANCES IN ATMOSPHERIC SCIENCES, 23, 282-290.  doi: 10.1007/s00376-006-0282-0
    [16] Gao Shouting, 1988: NONLINEAR ROSSBY WAVE INDUCED BY LARGE-SCALE TOPOGRAPHY, ADVANCES IN ATMOSPHERIC SCIENCES, 5, 301-310.  doi: 10.1007/BF02656754
    [17] Luo Dehai, 1990: Topographically Forced Rossby Wave Instability and the Development of Blocking in the Atmosphere, ADVANCES IN ATMOSPHERIC SCIENCES, 7, 433-440.  doi: 10.1007/BF03008873
    [18] He Jianzhong, 1993: Topography and the Non-linear Rossby Wave in the Zonal Shear Basic Flow, ADVANCES IN ATMOSPHERIC SCIENCES, 10, 233-242.  doi: 10.1007/BF02919146
    [19] Lu Keli, Zhu Yongchun, 1994: Seasonal Variation of Stationary and Low-Frequency Rossby Wave Rays, ADVANCES IN ATMOSPHERIC SCIENCES, 11, 427-435.  doi: 10.1007/BF02658163
    [20] Liao Qinghai, Li Chongyin, 1995: CISK-rossby wave and the 30-60 Day Oscillation in the Tropics, ADVANCES IN ATMOSPHERIC SCIENCES, 12, 1-12.  doi: 10.1007/BF02661282

Get Citation+

Export:  

Share Article

Manuscript History

Manuscript received: 10 October 1995
Manuscript revised: 10 October 1995
通讯作者: 陈斌, bchen63@163.com
  • 1. 

    沈阳化工大学材料科学与工程学院 沈阳 110142

  1. 本站搜索
  2. 百度学术搜索
  3. 万方数据库搜索
  4. CNKI搜索

Some Aspects of the Characteristics of Monsoon Disturbances Using a Combined Barotropic-Baroclinic Model

  • 1. Centre for Atmospheric Sciences, Indian Institute of Technology, Hauz Khas, New Delhi-110016, India,Centre for Atmospheric Sciences, Indian Institute of Technology, Hauz Khas, New Delhi-110016, India

Abstract: A standing Rossby wave of wavelength 30o longitude with a finite amplitude along the meridional direction is superimposed on the zonal mean component of the monsoon flow and the stability of such a flow is examined by a quasi-geostrophic barotropic, as well as by a quasi-geostrophic combined barotropic and baroclinic model on a beta plane centered at 18oN latitude. It is found that the growth of synoptic scale disturbance increases with the amplitude of the meridional wind. The barotropic stability analysis at 700 hPa pressure level shows that there is a critical value (Umax=11m/s) of the maximum mean zonal wind below which the computed disturbance moves to the west due to the wave-wave superposition. For maximum mean zonal wind greater that 11 m / s, the westerly wind dominates and the disturbance moves to the east. In another analysis the stability of the zonally asymmetric basic flow is studied with a combined barotropic-baroclinic model where cumulus heating is included. The growth rate, intensity, horizontal scale and the westward velocity of computed disturbances reasonably agree with those of observed monsoon disturb?ances. The fastest growing mode has a horizontal wavelength of 2000 kms and the e-folding time is about 3 days, when the meridional amplitude of the Rossby wave is 4 m / s at 700 hPa pressure level. When cumulus heating is in?cluded in the analysis the intensity of geopotential perturbation at 700 hPa disturbance is -304 m2 / s2. Energy calcu?lations show that the kinetic energy of the mean zonal flow is the main source of energy for the perturbation to grow. It is also found that the contribution of the kinetic energy of the basic Rossby wave to the growth of perturbation is more in comparison to the available potential energy.

Catalog

    /

    DownLoad:  Full-Size Img  PowerPoint
    Return
    Return