第26回 ESCセミナー
High-resolution coupled air-sea modeling for short-term forecasting
- 日時
- 2007年7月11日 (水) 14:00-15:00
- 場所
- 横浜研究所 シミュレータ研究棟1階 大会議室
- 講演者
- Dr. Julie Pullen (Naval Research Laboratory - Monterey, California)
- 使用言語
- 英語
要旨
Research efforts to simulate coupled ocean/atmosphere dynamics using a globally-relocatable coupled modeling system, COAMPS, are presented For the Adriatic and Philippines regions.
High-resolution numerical simulations of the Adriatic Sea were conducted to examine the impact of the coupling strategy (one versus two way) on the ocean and atmosphere model skill, and to elucidate dynamical aspects of the coupled response. Simulations for 23 September-23 October 2002 utilized 2- and 4-km resolution grids for the ocean and atmosphere, respectively. During a strong wind and sea surface cooling event, cold water fringed the west and north coasts in the two-way coupled simulation (where the atmosphere interacted with SST generated by the ocean model) and attenuated by approximately 20% of the cross-basin extension of bora-driven upward heat fluxes relative to the one-way coupled simulation (where the atmosphere model was not influenced by the ocean model). An assessment of model results using remotely sensed and in situ measurements of ocean temperature along with overwater and coastal wind observations showed enhanced skill in the two-way coupled model. In particular, the two-way coupled model produced spatially complex SSTs after the cooling event that compared more favorably (using mean bias and rms error) with satellite multichannel SST (MCSST)and had a stabilizing effect onthe atmosphere. As a consequence, mean mixing was suppressed by over 20% in the atmospheric boundary layer and more realistic mean 10-m wind speeds were produced during The monthlong two-way coupled simulation.
Winter monsoon conditions during February 2005 around the Philippines region were simulated at 8 km resolution for the atmosphere and 3 km resolution for the ocean. The high-resolution COAMPS model produced intense wind jets associated with the mountain orography and gaps between islands. The structure of the simulated features agreed with contemporaneous QuikSCAT-derived wind stresses. The strong curl of these wind jets leads to a double gyre ocean circulation pattern near Mindoro Straits. Sensitivity simulations utilizing either global NCOM or global HYCOM (both data-assimilating) for initial and boundary ocean conditions produced the wind-driven ocean gyre structure although the general background circulation was very different between the two global ocean models. A two-way coupled test is also being run for the region.
問い合わせ先
地球シミュレータセンター大気・海洋シミュレーション研究グループ
佐々木 英治
Phone : 045-778-5843
Fax : 045-778-5493
e-mail :
