Seasonal Difference of the Deep Currents in the Luzon Strait during October 2008-January 2009 and July-August 2009

• 作者: Chenghao Yang Huiqun Wang Weibing Guan Yaochu Yuan Yu-Heng Tseng
• 来源期刊: 大气和气候科学(英文)
• 学科: 医学
• 关键词: LUZON STRAIT Long Measurement of DEEP CURRENTS SEASONAL DIFFERENCE Rectified Wavelet Power Spectra Analysis Dynamical Cause of Resulting DEEP Current Distribution
• 年，卷（期）: 2019,（3）
• 页码范围: 284-297
• 页数: 14页
• 分类号: R73

摘要

Based on direct current measurements from two separated cruises in October 2008-January 2009 and July-August 2009, we obtained a valuable deep current observation of the Luzon Strait (LS). Rectified wavelet power spectra analysis (RWPSA) and the geostrophic current calculation are used to study the deep current. We find that the deep current differs in different seasons. The current is strongest in autumn (October-November) and weaker in summer (July-August) and in winter (December-January). The cyclonic and anti-cyclonic meander with different subtidal current directions plays an important role in the seasonal difference of the deep current in the LS. The observed seasonal difference of the deep current in the LS is connected with the deep current observed at the western boundary of the northern Philippine Basin and is also linked with the overflow near the central Bashi Channel and Luzon Trough. The RWPSA of the long observation suggests the dominant periods of 8 d, 19 d in the deep current. The dynamical cause of the resulting velocity distribution at 1850 and 1760 m is the pressure field and bottom topography steering. The observed deep current agrees well with the geostrophic current calculation.