領域大気海洋結合モデルの不確実性の検証  [in Japanese] A VALIDATION OF REGIONAL ATMOSPHERE-OCEAN COUPLING MODEL  [in Japanese]

Access this Article

Author(s)

Abstract

領域大気海洋結合モデルRSM-ROMSの不確実性検証を目的とし,CORDEXアジア域で力学的ダウンスケーリングシミュレーション実験を行った.RSM-ROMSによる実験結果を領域大気モデルRSMによる実験結果や観測,再解析データと比較した.本研究の結果は以下のようにまとめられる.<br> 1) RSM-ROMSの海面温度は観測データに対し低温傾向を持つが,相関係数0.99で,観測データの年々変動や季節変動を捉えた.またパワースペクトルはRSMより詳細な構造を示した.<br> 2) RSMで現れた山間部の多雨傾向がRSM-ROMSで増加した一方で,海上降水量の誤差は減少した.<br> 3) RSM-ROMSは水深 100mの海水温に4℃以上の低温傾向を持つが,海面温度と同様に季節変動を捉えた.RSM-ROMSの海水温の誤差は季節変動より大きく,不確実性を示唆した.<br> 4) 熱帯域においてRSM-ROMSで海面の正味熱フラックス誤差が改善されたが,中緯度域では誤差が増加した.

 We conducted dynamical downscaling simulations for 20 years over the Asian CORDEX domain to validate uncertainty of RSM-ROMS, a regional atmosphere and ocean coupled climate model. We compared some surface quantities simulated by RSM-ROMS with observation data sets or simulated result by RSM, a regional atmosphere climate model. The results are summarized as follows.<br> 1) The coupled model had some systematic negative bias for observed sea surface temperature (SST), but the correlation coefficient was over 0.99 and the model reasonably captured the interannual and seasonal variations. In addition, power spectrum suggested a detailed SST structure.<br> 2) The ocean coupling increased a tendency to overestimate precipitation over the mountainous area. On the other hand, the coupled model more accurately reproduced precipitation over the oceans.<br> 3) Although there was cool bias of sea water temperature (SWT) more than 4 degrees Celsius at 100m depth, the coupled model captured interannual validations of SWT as similar as those of SST. This SWT bias is larger than seasonal variations, and it indicates there is uncertainty in the coupled model.<br> 4) Net heat flux was improved in the coupled model, especially in subtropical and tropical areas but got worse in middle latitude areas.

Journal

  • Journal of Japan Society of Civil Engineers, Ser. B1 (Hydraulic Engineering)

    Journal of Japan Society of Civil Engineers, Ser. B1 (Hydraulic Engineering) 74(4), I_157-I_162, 2018

    Japan Society of Civil Engineers

Codes

Page Top