Intense Abyssal Flow Through the Yap‐Mariana Junction in the Western North Pacific
Chun Zhou, Hongzhou Xu, Xin Xiao, Wei Zhao, Jiayan Yang, Qingxuan Yang, Huichang Jiang, Qiang Xie, Tong Long, Tinghao Wang, Xiaodong Huang, Zhiwei Zhang, Shoude Guan, Jiwei Tian
Abstract
Abstract Water‐mass transports in the vast and seemingly quiescent abyssal ocean, basically along topographically‐guided pathways, play a pivotal role in the Earth's climate. The pulse of abyssal circulations can be taken with observations at topographic choke points. The Yap‐Mariana Junction (YMJ) is the exclusive choke point through which the Lower Circumpolar Deep Water (LCDW) enters the Philippine Sea. Here, we quantify the LCDW transport and its variability based on mooring observations at the YMJ and the Mariana Trench (MT). The LCDW flows northward toward the Philippine Sea as an intensified current on the western side of the YMJ, with maximum mean velocity reaching 7.6 cm/s. The mean LCDW transports through the MT and the YMJ are 2.2 ± 1.0 Sv and 2.1 ± 0.4 Sv, respectively. Reversal flow at autumn in both the YMJ and MT is captured, indicating seasonal variability of the abyssal flow.