Shang-Ping Xie, Scripps Institution of Oceanography, La Jolla, CA, United States, Sarah M Kang, Ulsan National Institute of Science and Technology, Ulsan, Korea, Republic of (South), Jiyeong Kim, Ulsan National Institute of Science and Technology, Ulsan, South Korea and Baoqiang Xiang, Geophysical Fluid Dynamics Laboratory, Princeton, NJ, United States