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Article Type:
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Interannual Variations of Summer Monsoons: Sensitivity to Cloud Radiative Forcing

O. P. Sharma Laboratoire de Météorologie Dynamique, Ecole Normale Supérieure, Paris, France

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H. Le Treut Laboratoire de Météorologie Dynamique, Ecole Normale Supérieure, Paris, France

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G. Sèze Laboratoire de Météorologie Dynamique, Ecole Normale Supérieure, Paris, France

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L. Fairhead Laboratoire de Météorologie Dynamique, Ecole Normale Supérieure, Paris, France

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R. Sadourny Laboratoire de Météorologie Dynamique, Ecole Normale Supérieure, Paris, France

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Print Publication:
01 Aug 1998
DOI:
https://doi.org/10.1175/1520-0442(1998)011<1883:IVOSMS>2.0.CO;2
Page(s):
1883–1905
Restricted access

Abstract

The sensitivity of the interannual variations of the summer monsoons to imposed cloudiness has been studied with a general circulation model using the initial conditions prepared from the European Centre for Medium-Range Forecasts analyses of 1 May 1987 and 1988. The cloud optical properties in this global model are calculated from prognostically computed cloud liquid water. The model successfully simulates the contrasting behavior of these two successive monsoons. However, when the optical properties of the observed clouds are specified in the model runs, the simulations show some degradation over India and its vicinity. The main cause of this degradation is the reduced land–sea temperature contrast resulting from the radiative effects of the observed clouds imposed in such simulations. It is argued that the high concentration of condensed water content of clouds over the Indian land areas will serve to limit heating of the land, thereby reducing the thermal contrast that gives rise to a weak Somali jet. A countermonsoon circulation is, therefore, simulated in the vector difference field of 850-hPa winds from the model runs with externally specified clouds. This countermonsoon circulation is associated with an equatorial heat source that is the response of the model to the radiative effects of the imposed clouds. Indeed, there are at least two clear points that can be made: 1) the cloud–SST patterns, together, affect the interannual variability; and 2) with both clouds and SST imposed, the model simulation is less sensitive to initial conditions. Additionally, the study emphasizes the importance of dynamically consistent clouds developing in response to the dynamical, thermal, and moist state of the atmosphere during model integrations.

Corresponding author address: Dr. O. P. Sharma, Centre for Atmospheric Sciences, Indian Institute of Technology, New Delhi 110016, India. E-mail: opsharma@henna.iitd.ernet.in

Abstract

The sensitivity of the interannual variations of the summer monsoons to imposed cloudiness has been studied with a general circulation model using the initial conditions prepared from the European Centre for Medium-Range Forecasts analyses of 1 May 1987 and 1988. The cloud optical properties in this global model are calculated from prognostically computed cloud liquid water. The model successfully simulates the contrasting behavior of these two successive monsoons. However, when the optical properties of the observed clouds are specified in the model runs, the simulations show some degradation over India and its vicinity. The main cause of this degradation is the reduced land–sea temperature contrast resulting from the radiative effects of the observed clouds imposed in such simulations. It is argued that the high concentration of condensed water content of clouds over the Indian land areas will serve to limit heating of the land, thereby reducing the thermal contrast that gives rise to a weak Somali jet. A countermonsoon circulation is, therefore, simulated in the vector difference field of 850-hPa winds from the model runs with externally specified clouds. This countermonsoon circulation is associated with an equatorial heat source that is the response of the model to the radiative effects of the imposed clouds. Indeed, there are at least two clear points that can be made: 1) the cloud–SST patterns, together, affect the interannual variability; and 2) with both clouds and SST imposed, the model simulation is less sensitive to initial conditions. Additionally, the study emphasizes the importance of dynamically consistent clouds developing in response to the dynamical, thermal, and moist state of the atmosphere during model integrations.

Corresponding author address: Dr. O. P. Sharma, Centre for Atmospheric Sciences, Indian Institute of Technology, New Delhi 110016, India. E-mail: opsharma@henna.iitd.ernet.in

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  • Atlas, R., N. Wolfson, and J. Terry, 1993: The effect of SST and soil moisture anomalies on GLA model simulations of the 1988 U.S. summer drought. J. Climate,6, 2034–2048.

  • Bony, S., H. Le Treut, J.-P. Duvel, and R. S. Kandel, 1992: Satellite validation of GCM simulated annual cycle of earth radiation budget and cloud forcing. J. Geophys. Res.,97, 18 061–18 081.

  • Boyle, J. S., 1993: Sensitivity of dynamical quantities to horizontal resolution for a climate simulation using the ECMWF (cycle 33) model. J. Climate,6, 796–815.

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

  • ——, W. J. Quirk, S.-H. Chow, and J. Kornfield, 1977: A comparative study of effects of albedo change on drought in semi-arid regions. J. Atmos. Sci.,34, 1366–1385.

  • Chen, T.-C., and M.-C. Yen, 1994: Interannual variation of the Indian monsoon simulated by the NCAR Community Climate Model: Effect of the tropical Pacific SST. J. Climate,7, 1403–1415.

  • Dakshinamurti, J., and R. N. Keshavamurty, 1976: An oscillation of period about one month in the Indian summer monsoon. Indian J. Meteor. Geophys.,27, 201–203.

  • Das, S. N., M. R. M. Rao, and N. C. Biswas, 1988: Monsoon season (June–September 1987). Mausam,39, 325–340.

  • ——, D. S. Desai, and N. C. Biswas, 1989: Monsoon season (June–September 1988). Mausam,40, 351–364.

  • Ducoudré, N., K. Laval, and A. Perrier, 1993: SECHIBA, a new set of parameterizations of the hydrologic exchanges at the land–atmosphere interface within the LMD atmospheric general circulation model. J. Climate,6, 248–273.

  • Flohn, H., 1960: Recent investigations on the mechanism of the“summer monsoon” of the southern and eastern Asia. Monsoons of the World, S. Basu et al., Eds., Hind Union Press, 75–88.

  • Fouquart, Y., J. C. Buriez, M. Herman, and R. S. Kandel, 1990: The influence of clouds on radiation: A climate modeling perspective. Rev. Geophys.,28, 145–166.

  • Gill, A., 1980: Some simple solutions of heat-induced tropical circulation. Quart. J. Roy. Meteor. Soc.,106, 447–462.

  • Hou, A. Y., and R. S. Lindzen, 1992: The influence of concentrated heating on Hadley circulation. J. Atmos. Sci.,49, 1233–1241.

  • Jaeger, L., 1976: Monatskarten des Niederschlages für die ganze Erde. Ber. Dtsch. Wetterdienstes,139, 1–38.

  • Koteswaram, P., 1958: Easterly jet stream in the tropics. Tellus,10, 407–410.

  • Krishnamurti, T. N., 1971: Observational study of the tropical upper tropospheric motion field during the Northern Hemisphere summer. J. Appl. Meteor.,10, 1066–1096.

  • ——, H. S. Bedi, and M. Subramaniam, 1989: The summer monsoon of 1987. J. Climate,2, 321–340.

  • ——, ——, and ——, 1990: The summer monsoon of 1988. Meteor. Atmos. Phys.,42, 19–37.

  • Laval, K., R. Raghava, R. Sadourny, and M. Forichon, 1996: Simulations of the 1987 and 1988 Indian monsoons using the LMD GCM. J. Climate,9, 3357–3372.

  • Legates, D. R., and C. J. Willmott, 1990: Mean seasonal and spatial variability in gauge-corrected, global precipitation. Int. J. Climatol.,10, 111–127.

  • Le Treut, H., Z. X. Li, and M. Forichon, 1994: Sensitivity of the LMD General Circulation Model to greenhouse forcing associated with two different cloud water parameterizations. J. Climate,7, 1827–1841.

  • Lindzen, R. S., and A. Y. Hou, 1988: Hadley circulations for zonally averaged heating centered off the equator. J. Atmos. Sci,45, 2416–2427.

  • Madden, R. A., and P. R. Julian, 1994: Observations of 40–50-day tropical oscillations—A review. Mon. Wea. Rev.,122, 814–836.

  • Meehl, G. A., 1994a: Influence of the land surface in the Asian summer monsoon: External conditions versus internal feedbacks. J. Climate,7, 1033–1049.

  • ——, 1994b: Coupled land–ocean–atmosphere processes and south Asian monsoon variability. Science,226, 263–267.

  • Pal, P. K., A. Kasahara, and A. P. Mizzi, 1993: Interannual variability in circulations and energetics of a climate model over Asian summer monsoon region. Tech. Rep. ISRO-SAC-TR-99-93, Indian Space Research Organisation, Bangalore, India, 48 pp. [Available from Publications and Public Relations Unit, ISRO Headquarters, Antariksh Bhavan, New BEL Road, Bangalore 560 027, India.].

  • Palmer, T. N., C. Branković, F. Molteni, and S. Tibaldi, 1990: Extended range predictions with ECMWF models: Interannual variability in operational model integrations. Quart. J. Roy. Meteor. Soc.,116, 799–834.

  • ——, ——, P. Viterbo, and M. J. Miller, 1992: Modeling interannual variations of monsoons. J. Climate,5, 399–417.

  • Paltridge, G. W., and C. M. R. Platt, 1976: Radiative Processes in Meteorology and Climatology. Elsevier, 318 pp.

  • Raghavan, K., 1973: Break-monsoon over India. Mon. Wea. Rev.,101, 33–43.

  • Rao, Y. P., 1976: Southwest monsoon. Synoptic Meteorology, Meteor. Monogr., No. 1, India Meteor. Dept., 1–367.

  • Rossow, W. B., and R. A. Schiffer, 1991: ISCCP cloud data products. Bull. Amer. Meteor. Soc.,72, 2–20.

  • ——, A. W. Walker, and L. C. Garder, 1993: Comparison of ISCCP and other cloud amounts. J. Climate,6, 2394–2418.

  • Sadler, J. C., 1975: The upper tropospheric circulation over the global tropics. UHMET-75-05, University of Hawaii, Honolulu, HI, 35 pp. [ Available from Dept. of Meteorology, University of Hawaii at Manoa, Honolulu, HI 96822.].

  • Sadourny, R., and K. Laval, 1984: January and July performances of LMD general circulation model. New Perspectives in Climate Modeling, A. Berger, Ed., Elsevier, 173–198.

  • Shukla, J., 1981: Dynamical predictability of monthly means. J. Atmos. Sci.,38, 2547–2572.

  • Sikka, D. R., and S. Gadgil, 1980: On the maximum cloud zone and the ITCZ over Indian longitudes during the southwest monsoon. Mon. Wea. Rev.,108, 1840–1853.

  • 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, 2727–2750.

  • ——, S. Hameed, G. L. Potter, and J. S. Boyle, 1994: Simulation of the northern summer monsoon in the ECMWF model: Sensitivity to horizontal resolution. Mon. Wea. Rev.,122, 2461–2481.

  • Stephens, G. L., S. Tsay, P. W. Stackhouse, and P. J. Flatau, 1990: The relevance of microphysical and radiative properties of cirrus clouds on climate and climate feedbacks. J. Atmos. Sci.,47, 1742–1753.

  • Tselioudis, G., W. B. Rossow, and D. Rind, 1992: Global patterns of cloud optical thickness variation with temperature. J. Climate,5, 1484–1495.

  • WCRP, 1992: Simulation of interannual and intraseasonal monsoon variability. WCRP-68, WMP/TD-470, WCRP, Geneva, Switzerland, 231 pp. [Available from Joint Planning Staff for WCRP, c/o World Meteorological Organization, Case Postale No. 2300, CH-1211 Geneva 20, Switzerland.].

  • ——, 1993: Simulation and prediction of monsoons, recent results. WCRP-80, WMP/TD-546, WCRP, Geneva, Switzerland, 82 pp. [Available from Joint Planning Staff for WCRP, c/o World Meteorological Organization, Case Postale No. 2300, CH-1211 Geneva 20, Switzerland.].

  • Weare, B. C., 1992: A comparison of ISCCP C1 cloud amounts with those derived from high resolution AVHRR images. Int. J. Remote Sens.,13, 1965–1980.

  • Yasunari, T., 1979: Cloudiness fluctuations associated with the Northern Hemisphere summer monsoon. J. Meteor. Soc. Japan,57, 227–242.

  • Yeh, T.-C., 1982: Some aspect of thermal influences of Quinghai-Tibetan Plateau on the atmospheric circulation. Arch. Meteor. Geophys. Bioklimatol.,31A, 205–220.

  • Zhang, Z., and T. N. Krishnamurti, 1996: A generalization of Gill’s heat-induced tropical circulation. J. Atmos. Sci.,53, 1045–1052.

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