1993年8月6日に起こった鹿児島豪雨を対象とした静水圧モデルと非静水圧モデルとの比較実験 Hydrostatic and Non-hydrostatic Simulations of the 6 August 1993 Kagoshima Torrential Rain

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Abstract

1993年8月6日に起こった鹿児島豪雨を対象として静水圧モデルと非静水圧モデルとで雨の降り方にどのような違いが生じるかについて調べてみた. 数値モデルとして気象庁の現業用日本域静水圧モデル(Japan Spectal Model)を親モデルとしてネスティングすることができる3次元非弾性非静水圧モデル(Saito, 1994)とそのモデルの静水圧バージョン(Kato and Saito, 1995)を用いた. 降水生成過程として雲水, 雨水を直接予報する雲物理過程と湿潤対流調節をそれぞれ単独にまたは併用して用いた. 雲物理過程を用いた5kmと10km格子の非静水圧モデルは観測とよく一致した連続的な集中豪雨を再現した. Kato and Saito (1995) が理想的な湿潤対流を対象とした比較実験で指摘した通り, 静水圧モデルは非静水圧モデルに比べ雨を過大に降らせ, 降雨域を過大に広げた. また, water loadingの効果が非静水圧の効果より対流の発達には重要であった. さらに, 5km格子の静水圧モデルはKato and Saito (1995) で取り扱った理想的な湿潤対流の場合に比べかなり過大に雨を降らした. 以上の結果より, 高分解能の数値予報モデルにはwater loadingを取り入れた非静水圧モデルを用いることが望まれる.

Comparative experiments with real data using hydrostatic and non-hydrostatic models are performed for the torrential rain which occurred on 6 August 1993 in Kagoshima, the southern Kyushu, Japan. A modified version of the three-dimensional anelastic model (Saito, 1994; Kato and Saito, 1995) is used, which is nested with the operational hydrostatic model (the Japan Spectral Model) of the Japan Meteorological Agency. An explicit warm rain process predicting cloud water and rainwater and the moist convective adjustment are individually or conjunctionally employed in the model. The non-hydrostatic simulations of 5 and 10 km horizontal-resolution with a warm rain scheme reproduce continuously heavy rain which corresponds well with the observation. As Kato and Saito (1995) pointed out in a previous comparative experiment of ideal moist convection, the hydrostatic simulation tends to overestimate and overexpand precipitation in comparison with the non-hydrostatic counterpart, and the drag effect of hydrostatic water loading is more significant for convective development than the non-hydrostatic effect. Furthermore, in the 5 km simulations, the hydrostatic approximation greatly overestimates the total precipitation, more than in the simulation of ideal moist convection (Kato and Saito, 1995). From these results, a non-hydrostatic model with hydrostatic water loading is recommended for a high-resolution numerical prediction model.

Journal

  • Journal of the Meteorological Society of Japan. Ser. II

    Journal of the Meteorological Society of Japan. Ser. II 74(3), 355-363, 1996-06-25

    Meteorological Society of Japan

References:  15

Cited by:  10

Codes

  • NII Article ID (NAID)
    110001807410
  • NII NACSIS-CAT ID (NCID)
    AA00702524
  • Text Lang
    ENG
  • Article Type
    Journal Article
  • ISSN
    00261165
  • NDL Article ID
    3974878
  • NDL Source Classification
    ZM43(科学技術--地球科学--気象)
  • NDL Call No.
    Z15-110
  • Data Source
    CJP  CJPref  NDL  NII-ELS  J-STAGE  NDL-Digital 
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