A Time-Lagged Ensemble Simulation on the Modulation of Precipitation over West Java in January–February 2007

Nurjanna J. Trilaksono Department of Geophysics, Kyoto University, Kyoto, Japan

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Shigenori Otsuka Department of Geophysics, Kyoto University, Kyoto, Japan

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Shigeo Yoden Department of Geophysics, Kyoto University, Kyoto, Japan

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Abstract

A numerical experiment using a regional nonhydrostatic model is performed to investigate the synoptic condition related to the heavy precipitation event that occurred at Jakarta in West Java, Indonesia, in January–February 2007. A time-lagged ensemble forecast method is employed with nine ensemble members. The ensemble mean well reproduces the temporal modulation of the spatial distributions of precipitation obtained from the Tropical Rainfall Measuring Mission data.

During the simulated two months, several monsoon surges are observed, but only the surge event during which the Jakarta flood event occurred is associated with a cold anomaly. The top of the cold northerly is about 1.5 km. The cold surge event is preceded by the so-called Borneo vortex event, which is dominated by a cyclonic vortex around Borneo, Indonesia, with a horizontal scale of 1000 km and a vertical scale of 3 km.

An analysis of cumulative distribution functions in a pentad time scale shows the modulation of the probability of rainfall rate. In pentad 7 (31 January–4 February), which includes the heavy rainfall event, the fraction of the area with precipitation is the highest and the contribution of heavy rainfall to the total amount is one of the highest in the two-month period. The diurnal cycle of occurrence of heavy rainfall is also modulated; in pentad 7, semidiurnal variation becomes dominant, and the largest peak appears in the early morning.

Additional affiliation: Faculty of Earth Sciences and Technology, Institut Teknologi Bandung, Bandung, Indonesia.

Corresponding author address: Shigeo Yoden, Department of Geophysics, Kyoto University, Kyoto 606-8502, Japan. E-mail: yoden@kugi.kyoto-u.ac.jp

Abstract

A numerical experiment using a regional nonhydrostatic model is performed to investigate the synoptic condition related to the heavy precipitation event that occurred at Jakarta in West Java, Indonesia, in January–February 2007. A time-lagged ensemble forecast method is employed with nine ensemble members. The ensemble mean well reproduces the temporal modulation of the spatial distributions of precipitation obtained from the Tropical Rainfall Measuring Mission data.

During the simulated two months, several monsoon surges are observed, but only the surge event during which the Jakarta flood event occurred is associated with a cold anomaly. The top of the cold northerly is about 1.5 km. The cold surge event is preceded by the so-called Borneo vortex event, which is dominated by a cyclonic vortex around Borneo, Indonesia, with a horizontal scale of 1000 km and a vertical scale of 3 km.

An analysis of cumulative distribution functions in a pentad time scale shows the modulation of the probability of rainfall rate. In pentad 7 (31 January–4 February), which includes the heavy rainfall event, the fraction of the area with precipitation is the highest and the contribution of heavy rainfall to the total amount is one of the highest in the two-month period. The diurnal cycle of occurrence of heavy rainfall is also modulated; in pentad 7, semidiurnal variation becomes dominant, and the largest peak appears in the early morning.

Additional affiliation: Faculty of Earth Sciences and Technology, Institut Teknologi Bandung, Bandung, Indonesia.

Corresponding author address: Shigeo Yoden, Department of Geophysics, Kyoto University, Kyoto 606-8502, Japan. E-mail: yoden@kugi.kyoto-u.ac.jp
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  • Branković, Č., T. N. Palmer, F. Molteni, S. Tibaldi, and U. Cubasch, 1990: Extended-range predictions with ECMWF models: Time-lagged ensemble forecasting. Quart. J. Roy. Meteor. Soc., 116, 867912.

    • Search Google Scholar
    • Export Citation
  • Chang, C.-P., P. A. Harr, and H.-J. Chen, 2005: Synoptic disturbances over the equatorial South China Sea and western Maritime Continent during boreal winter. Mon. Wea. Rev., 133, 489503.

    • Search Google Scholar
    • Export Citation
  • Cheang, B. K., 1977: Synoptic features and structures of some equatorial vortices over the South China Sea in the Malaysian region during the winter monsoon of December 1973. Pure Appl. Geophys., 115, 13031333.

    • Search Google Scholar
    • Export Citation
  • Chelton, D. B., and M. H. Freilich, 2005: Scatterometer-based assessment of 10-m wind analyses from the operational ECMWF and NCEP numerical weather prediction models. Mon. Wea. Rev., 133, 409429.

    • Search Google Scholar
    • Export Citation
  • Compo, G. P., G. N. Kiladis, and P. J. Webster, 1999: The horizontal and vertical structure of east Asian winter monsoon pressure surges. Quart. J. Roy. Meteor. Soc., 125, 2954.

    • Search Google Scholar
    • Export Citation
  • Freilich, M. H., and R. S. Dunbar, 1999: The accuracy of the NSCAT 1 vector winds: Comparisons with National Data Buoy Center buoys. J. Geophys. Res., 104, 11 23111 246.

    • Search Google Scholar
    • Export Citation
  • Hayashi, S., K. Aranami, and K. Saito, 2008: Statistical verification of short term NWP by NHM and WRF-ARW with 20 km horizontal resolution around Japan and Southeast Asia. SOLA, 4, 133136.

    • Search Google Scholar
    • Export Citation
  • Hirose, M., and K. Nakamura, 2005: Spatial and diurnal variation of precipitation systems over Asia observed by the TRMM Precipitation Radar. J. Geophys. Res., 110, D05106, doi:10.1029/2004JD004815.

    • Search Google Scholar
    • Export Citation
  • Huffman, G. J., and Coauthors, 2007: The TRMM Multisatellite Precipitation Analysis (TMPA): Quasi-global, multiyear, combined-sensor precipitation estimates at fine scales. J. Hydrometeor., 8, 3855.

    • Search Google Scholar
    • Export Citation
  • Johnson, R. H., and R. A. Houze Jr., 1987: Precipitating cloud systems of the Asian monsoon. Monsoon Meteorology, C.-P. Chang and T. N. Krishnamurti, Eds., Oxford University Press, 298–353.

    • Search Google Scholar
    • Export Citation
  • Juneng, L., F. T. Tangang, and C. J. C. Reason, 2007: Numerical case study of an extreme rainfall event during 9–11 December 2004 over the east coast Peninsular Malaysia. Meteor. Atmos. Phys., 98, 8198.

    • Search Google Scholar
    • Export Citation
  • Mittermaier, M. P., 2007: Improving short-range high-resolution model precipitation forecast skill using time-lagged ensembles. Quart. J. Roy. Meteor. Soc., 133, 14871500.

    • Search Google Scholar
    • Export Citation
  • Mori, S., and Coauthors, 2004: Diurnal land–sea rainfall peak migration over Sumatera Island, Indonesian Maritime Continent, observed by TRMM satellite and intensive rawinsonde soundings. Mon. Wea. Rev., 132, 20212039.

    • Search Google Scholar
    • Export Citation
  • Nakanishi, M., and H. Niino, 2004: An improved Mellor-Yamada level 3 model with condensation physics: Its design and verification. Bound.-Layer Meteor., 112, 131.

    • Search Google Scholar
    • Export Citation
  • Nakanishi, M., and H. Niino, 2006: An improved Mellor-Yamada level-3 model: Its numerical stability and application to a regional prediction of advection fog. Bound.-Layer Meteor., 119, 397407.

    • Search Google Scholar
    • Export Citation
  • Otsuka, S., and S. Yoden, 2005: Numerical experiments on the layered structures in the mid-troposphere over the equatorial Pacific. SOLA, 1, 6972.

    • Search Google Scholar
    • Export Citation
  • Saito, K., and Coauthors, 2006: The operational JMA nonhydrostatic mesoscale model. Mon. Wea. Rev., 134, 12661298.

  • Saito, K., J. Ishida, K. Aranami, T. Hara, T. Segawa, M. Narita, and Y. Honda, 2007: Nonhydrostatic atmospheric models and operational development at JMA. J. Meteor. Soc. Japan, 85B, 271304.

    • Search Google Scholar
    • Export Citation
  • Seko, H., S. Hayashi, M. Kunii, and K. Saito, 2008: Structure of the regional heavy rainfall system that occurred in Mumbai, India, on 26 July 2005. SOLA, 4, 129132.

    • Search Google Scholar
    • Export Citation
  • Suppiah, R., and X. Wu, 1998: Surges, cross-equatorial flows and their links with the Australian summer monsoon circulation and rainfall. Aust. Meteor. Mag., 47, 113130.

    • Search Google Scholar
    • Export Citation
  • Tangang, F. T., L. Juneng, E. Salimun, P. N. Vinayachandran, Y. K. Seng, C. J. C. Reason, S. K. Behera, and T. Yasunari, 2008: On the roles of the northeast cold surge, the Borneo vortex, the Madden-Julian Oscillation, and the Indian Ocean Dipole during the extreme 2006/2007 flood in southern Peninsular Malaysia. Geophys. Res. Lett., 35, L14S07, doi:10.1029/2008GL033429.

    • Search Google Scholar
    • Export Citation
  • Wangwongchai, A., S. Zhao, and Q. Zeng, 2005: A case study on a strong tropical disturbance and record heavy rainfall in Hat Yai, Thailand during winter monsoon. Adv. Atmos. Sci., 20, 436450.

    • Search Google Scholar
    • Export Citation
  • Wu, P., M. Hara, H. Fudeyasu, M. D. Yamanaka, J. Matsumoto, F. Syamsudin, R. Sulistyowati, and Y. S. Djajadihardja, 2007: The impact of trans-equatorial monsoon flow on the formation of repeated torrential rains over Java Island. SOLA, 3, 9396.

    • Search Google Scholar
    • Export Citation
  • Yabu, S., S. Murai, and H. Kitagawa, 2005: Clear-sky radiation scheme (in Japanese). NPD Rep., Vol. 51, Numerical Prediction Division, JMA, 53–64.

    • Search Google Scholar
    • Export Citation
  • Yoden, S., 2007: Atmospheric predictability. J. Meteor. Soc. Japan, 85B, 77102.

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