Internal Feedbacks from Monsoon–Midlatitude Interactions during Droughts in the Indian Summer Monsoon

R. Krishnan Indian Institute of Tropical Meteorology, Pashan, Pune, India

Search for other papers by R. Krishnan in
Current site
Google Scholar
PubMed
Close
,
Vinay Kumar Indian Institute of Tropical Meteorology, Pashan, Pune, India

Search for other papers by Vinay Kumar in
Current site
Google Scholar
PubMed
Close
,
M. Sugi Meteorological Research Institute, Tsukuba, Japan

Search for other papers by M. Sugi in
Current site
Google Scholar
PubMed
Close
, and
J. Yoshimura Meteorological Research Institute, Tsukuba, Japan

Search for other papers by J. Yoshimura in
Current site
Google Scholar
PubMed
Close
Restricted access

Abstract

Results from a 20-yr simulation of a high-resolution AGCM forced with climatological SST, along with simplified model experiments and supplementary data diagnostics, are used to investigate internal feedbacks arising from monsoon–midlatitude interactions during droughts in the Indian summer monsoon. The AGCM simulation not only shows a fairly realistic mean monsoon rainfall distribution and large-scale circulation features but also exhibits remarkable interannual variations of precipitation over the subcontinent, with the 20-yr run showing incidence of four “monsoon droughts.”

The present findings indicate that the internally forced droughts in the AGCM emanate largely from prolonged “monsoon breaks” that occur on subseasonal time scales and involve dynamical feedbacks between monsoon convection and extratropical circulation anomalies. In this feedback, the suppressed monsoon convection is shown to induce Rossby wave dispersion in the summertime subtropical westerlies and to set up an anomalous quasi-stationary circulation pattern extending across continental Eurasia in the middle and upper troposphere. This pattern is composed of a cyclonic anomaly over west central Asia and the Indo-Pakistan region, a meridionally deep anticyclonic anomaly over East Asia (∼100°E), and a cyclonic anomaly over the Far East. The results suggest that the anchoring of the west central Asia cyclonic anomaly by the stagnant ridge located downstream over East Asia induces anomalous cooling in the middle and upper troposphere through cold-air advection, which reduces the meridional thermal contrast over the subcontinent. Additionally, the intrusion of the dry extratropical winds into northwest India can decrease the convective instability, so that the suppressed convection can in turn weaken the monsoon flow. The sustenance of monsoon breaks through such monsoon–midlatitude feedbacks can generate droughtlike conditions over India.

Corresponding author address: R. Krishnan, Climate and Global Modelling Division, Indian Institute of Tropical Meteorology, Pashan, Pune 411008, India. Email: krish@tropmet.res.in

Abstract

Results from a 20-yr simulation of a high-resolution AGCM forced with climatological SST, along with simplified model experiments and supplementary data diagnostics, are used to investigate internal feedbacks arising from monsoon–midlatitude interactions during droughts in the Indian summer monsoon. The AGCM simulation not only shows a fairly realistic mean monsoon rainfall distribution and large-scale circulation features but also exhibits remarkable interannual variations of precipitation over the subcontinent, with the 20-yr run showing incidence of four “monsoon droughts.”

The present findings indicate that the internally forced droughts in the AGCM emanate largely from prolonged “monsoon breaks” that occur on subseasonal time scales and involve dynamical feedbacks between monsoon convection and extratropical circulation anomalies. In this feedback, the suppressed monsoon convection is shown to induce Rossby wave dispersion in the summertime subtropical westerlies and to set up an anomalous quasi-stationary circulation pattern extending across continental Eurasia in the middle and upper troposphere. This pattern is composed of a cyclonic anomaly over west central Asia and the Indo-Pakistan region, a meridionally deep anticyclonic anomaly over East Asia (∼100°E), and a cyclonic anomaly over the Far East. The results suggest that the anchoring of the west central Asia cyclonic anomaly by the stagnant ridge located downstream over East Asia induces anomalous cooling in the middle and upper troposphere through cold-air advection, which reduces the meridional thermal contrast over the subcontinent. Additionally, the intrusion of the dry extratropical winds into northwest India can decrease the convective instability, so that the suppressed convection can in turn weaken the monsoon flow. The sustenance of monsoon breaks through such monsoon–midlatitude feedbacks can generate droughtlike conditions over India.

Corresponding author address: R. Krishnan, Climate and Global Modelling Division, Indian Institute of Tropical Meteorology, Pashan, Pune 411008, India. Email: krish@tropmet.res.in

Save
  • Ambrizzi, T., B. J. Hoskins, and H-H. Hsu, 1995: Rossby wave propagation and teleconnection patterns in the austral winter. J. Atmos. Sci., 52 , 36613672.

    • Search Google Scholar
    • Export Citation
  • Annamalai, H., and K. R. Sperber, 2005: Regional heat sources and the active and break phases of boreal summer intraseasonal (30–50 day) variability. J. Atmos. Sci., 62 , 27262748.

    • Search Google Scholar
    • Export Citation
  • Asnani, G. C., 1993: Tropical Meteorology. Vol. 1. Indian Institute of Tropical Meteorology, 603 pp.

  • Bhat, G. S., 2006: The Indian drought of 2002 – A sub-seasonal phenomenon? Quart. J. Roy. Meteor. Soc., 132 , 25832602.

  • Brown, R. G., and C. Zhang, 1997: Variability of midtropospheric moisture and its effect on cloud-top height distribution during TOGA COARE. J. Atmos. Sci., 54 , 27602774.

    • Search Google Scholar
    • Export Citation
  • Charney, J. G., and J. Shukla, 1981: Predictability of monsoons. Monsoon Dynamics, J. Lighthill and R. P. Pearce, Eds., Cambridge University Press, 99–109.

    • Search Google Scholar
    • Export Citation
  • Ding, Q., and B. Wang, 2005: Circumglobal teleconnection in the Northern Hemisphere summer. J. Climate, 18 , 34833505.

  • Ding, Q., and B. Wang, 2007: Intraseasonal teleconnection between the Eurasian wave train and the Indian monsoon. J. Climate, 20 , 37513767.

    • Search Google Scholar
    • Export Citation
  • Enomoto, T., B. J. Hoskins, and Y. Matsuda, 2003: The formation mechanism of the Bonin high in August. Quart. J. Roy. Meteor. Soc., 129 , 157178.

    • Search Google Scholar
    • Export Citation
  • Ferranti, L., J. M. Slingo, T. N. Palmer, and B. J. Hoskins, 1997: Relations between interannual and intraseasonal monsoon variability as diagnosed from AMIP integrations. Quart. J. Roy. Meteor. Soc., 123 , 13231357.

    • Search Google Scholar
    • Export Citation
  • Flohn, H., 1957: Large-scale aspects of the “summer monsoon” in South and East Asia. J. Meteor. Soc. Japan, 75 , 180186.

  • Gadgil, S., and S. Sajani, 1998: Monsoon precipitation in the AMIP runs. Climate Dyn., 14 , 659689.

  • Gadgil, S., and P. V. Joseph, 2003: On breaks of the Indian monsoon. J. Earth Syst. Sci., 112 , 529558.

  • Goswami, B. N., 1998: Interannual variations of Indian summer monsoon in a GCM: External conditions versus internal feedbacks. J. Climate, 11 , 501522.

    • Search Google Scholar
    • Export Citation
  • Goswami, B. N., and R. S. Ajaya Mohan, 2001: Intraseasonal oscillations and interannual variability of the Indian summer monsoon. J. Climate, 14 , 11801198.

    • Search Google Scholar
    • Export Citation
  • Goswami, B. N., and R. S. Ajaya Mohan, 2005: Dynamics of “internal” interannual variability of the Indian summer monsoon in a GCM. J. Geophys. Res., 110 , D24104. doi:10.1029/2005JD006042.

    • Search Google Scholar
    • Export Citation
  • Hahn, D. G., and S. Manabe, 1975: The role of mountains in the south Asian monsoon circulation. J. Atmos. Sci., 32 , 15151541.

  • Hoskins, B. J., and D. J. Karoly, 1981: The steady linear response of a spherical atmosphere to thermal and orographic forcing. J. Atmos. Sci., 38 , 11791196.

    • Search Google Scholar
    • Export Citation
  • JMA, 1993: Outline of operational numerical weather prediction at the Japan Meteorological Agency: Appendix to progress report on Numerical Weather Prediction. Japan Meteorological Agency, 128 pp.

    • Search Google Scholar
    • Export Citation
  • Joseph, P. V., and J. Srinivasan, 1999: Rossby waves in May and the Indian summer monsoon rainfall. Tellus, 51A , 854864.

  • Julian, P. R., 1984: Objective analysis in the tropics: A proposed scheme. Mon. Wea. Rev., 112 , 17521767.

  • Kalnay, E., and Coauthors, 1996: The NCEP/NCAR 40-Year Reanalysis Project. Bull. Amer. Meteor. Soc., 77 , 437471.

  • Kang, I-S., and Coauthors, 2002: Intercomparison of the climatological variations of Asian summer monsoon precipitation simulated by 10 GCMs. Climate Dyn., 19 , 383395.

    • Search Google Scholar
    • Export Citation
  • Kar, S. C., M. Sugi, and N. Sato, 1996: Simulation of the Indian summer monsoon and its variability using the JMA global model. Pap. Meteor. Geophys., 47 , 65101.

    • Search Google Scholar
    • Export Citation
  • Kar, S. C., M. Sugi, and N. Sato, 2001: Interannual variability of the Indian summer monsoon and internal variability in the JMA global model simulations. J. Meteor. Soc. Japan, 79 , 607623.

    • Search Google Scholar
    • Export Citation
  • Keshavamurty, R. N., and S. T. Awade, 1974: Dynamical abnormalities associated with drought in the Asiatic summer monsoon. Indian J. Meteor. Geophys., 25 , 257266.

    • Search Google Scholar
    • Export Citation
  • Koteswaram, P., 1958: The easterly jet stream in the tropics. Tellus, 10 , 4356.

  • Kripalani, R. H., A. Kulkarni, and S. V. Singh, 1997: Association of the Indian summer monsoon with the Northern Hemisphere midlatitude circulation. Int. J. Climatol., 17 , 10551067.

    • Search Google Scholar
    • Export Citation
  • Krishnamurti, T. N., 1973: Tibetan high and upper tropospheric tropical circulation during northern summer. Bull. Amer. Meteor. Soc., 54 , 12341249.

    • Search Google Scholar
    • Export Citation
  • Krishnamurti, T. N., H. S. Bedi, and M. Subramaniam, 1989: The summer monsoon of 1987. J. Climate, 2 , 321340.

  • Krishnan, R., and M. Mujumdar, 1999: Remotely and regionally forced pre-monsoon signals over northern India and neighbourhood. Quart. J. Roy. Meteor. Soc., 125 , 5578.

    • Search Google Scholar
    • Export Citation
  • Krishnan, R., and M. Sugi, 2001: Baiu rainfall variability and associated monsoon teleconnections. J. Meteor. Soc. Japan, 79 , 851860.

    • Search Google Scholar
    • Export Citation
  • Krishnan, R., C. Venkatesan, and R. N. Keshavamurty, 1998: Dynamics of upper tropospheric stationary wave anomalies induced by ENSO during the northern summer: A GCM study. Proc. Indian Acad. Sci. (Earth Planet. Sci.), 107 , 6590.

    • Search Google Scholar
    • Export Citation
  • Krishnan, R., C. Zhang, and M. Sugi, 2000: Dynamics of breaks in the Indian summer monsoon. J. Atmos. Sci., 57 , 13541372.

  • Krishnan, R., M. Mujumdar, V. Vaidya, K. V. Ramesh, and V. Satyan, 2003: The abnormal Indian summer monsoon of 2000. J. Climate, 16 , 11771194.

    • Search Google Scholar
    • Export Citation
  • Krishnan, R., K. V. Ramesh, B. K. Samala, G. Meyers, J. Slingo, and M. J. Fennessy, 2006: Indian Ocean–monsoon coupled interactions and impending monsoon droughts. Geophys. Res. Lett., 33 , L08711. doi:10.1029/2006GL025811.

    • Search Google Scholar
    • Export Citation
  • Lau, K-M., and P. Chan, 1986: Aspects of the 40–50-day oscillation during the northern summer as inferred from outgoing longwave radiation. Mon. Wea. Rev., 114 , 13541367.

    • Search Google Scholar
    • Export Citation
  • Lau, K-M., and L. Peng, 1992: Dynamics of atmospheric teleconnections during the northern summer. J. Climate, 5 , 140158.

  • Li, C., and M. Yanai, 1996: The onset and interannual variability of the Asian summer monsoon in relation to land–sea thermal contrast. J. Climate, 9 , 358375.

    • Search Google Scholar
    • Export Citation
  • Liu, Y., B. J. Hoskins, and M. Blackburn, 2007: Impact of Tibetan orography and heating on the summer flow over Asia. J. Meteor. Soc. Japan, 85B , 119.

    • Search Google Scholar
    • Export Citation
  • Luo, H., and M. Yanai, 1984: The large-scale circulation and heat sources over the Tibetan Plateau and surrounding area during the early summer of 1979. Part II: Heat and moisture budgets. Mon. Wea. Rev., 112 , 966989.

    • Search Google Scholar
    • Export Citation
  • Palmer, T. N., and D. L. T. Anderson, 1994: The prospects for seasonal forecasting—A review paper. Quart. J. Roy. Meteor. Soc., 120 , 755793.

    • Search Google Scholar
    • Export Citation
  • Parthasarthy, B., A. A. Munot, and D. R. Kothawale, 1995: Monthly and seasonal rainfall series for All-India homogenous regions and meteorological subdivisions 1871–1994. IITM Research Rep. RR-065, Indian Institute of Tropical Meteorology, 113 pp.

    • Search Google Scholar
    • Export Citation
  • Ramamurthy, K., 1969: Some aspects of “break” in the Indian southwest monsoon during July and August. India Meteorological Department Forecasting Manual, Part 4, section 18.3.

    • Search Google Scholar
    • Export Citation
  • Raman, C. R. V., and Y. P. Rao, 1981: Blocking highs over Asia and monsoon droughts over India. Nature, 289 , 271273.

  • Ramaswamy, C., 1962: Breaks in the Indian summer monsoon as a phenomenon of interaction between the easterly and the subtropical westerly jet streams. Tellus, 14A , 337349.

    • Search Google Scholar
    • Export Citation
  • Ramaswamy, C., and R. S. Pareek, 1978: The southwest monsoon over India and its teleconnections with the middle and upper tropospheric flow patterns over the Southern Hemisphere. Tellus, 30 , 126135.

    • Search Google Scholar
    • Export Citation
  • Rodwell, M. J., 1997: Breaks in the Asian monsoon: The influence of the Southern Hemisphere weather systems. J. Atmos. Sci., 54 , 25972611.

    • Search Google Scholar
    • Export Citation
  • Rodwell, M. J., and B. J. Hoskins, 1996: Monsoons and the dynamics of deserts. Quart. J. Roy. Meteor. Soc., 122 , 13851404.

  • Sardeshmukh, P. D., and B. J. Hoskins, 1988: The generation of global rotational flow by steady idealized tropical divergence. J. Atmos. Sci., 45 , 12281251.

    • Search Google Scholar
    • Export Citation
  • Sperber, K. R., and T. N. Palmer, 1996: Interannual tropical rainfall variability in general circulation model simulations associated with the atmospheric model intercomparison project. J. Climate, 9 , 27272750.

    • Search Google Scholar
    • Export Citation
  • Sperber, K. R., J. M. Slingo, and H. Annamalai, 2000: Predictability and the relationship between subseasonal and interannual variability during the Asian summer monsoon. Quart. J. Roy. Meteor. Soc., 126 , 25452574.

    • Search Google Scholar
    • Export Citation
  • Sugi, M., K. Kuma, K. Tada, K. Tamiya, N. Hasegawa, T. Iwasaki, S. Yamada, and T. Kitade, 1990: Description and performance of the JMA operational global spectral model (JMA-GSM88). Geophys. Mag., 43 , 105130.

    • Search Google Scholar
    • Export Citation
  • Sugi, M., R. Kawamura, and N. Sato, 1997: A study of SST-forced variability and potential predictability of seasonal mean fields using the JMA global model. J. Meteor. Soc. Japan, 75 , 717736.

    • Search Google Scholar
    • Export Citation
  • Terao, T., 1999: The zonal wavelength of the quasi-stationary Rossby waves trapped in the westerly jet. J. Meteor. Soc. Japan, 77 , 687699.

    • Search Google Scholar
    • Export Citation
  • Wang, B., I-S. Kang, and J-Y. Lee, 2004: Ensemble simulation of Asian–Australian monsoon variability by 11 AGCMs. J. Climate, 17 , 803818.

    • Search Google Scholar
    • Export Citation
  • Yanai, M., and G-X. Wu, 2006: Effects of the Tibetan Plateau. The Asian–Monsoon, B. Wang, Ed., Springer-Praxis, 513–549.

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 799 275 15
PDF Downloads 611 167 12