The Slow Coastal-Trapped Waves off Subei Bank in the Yellow Sea and Their Climatic Change in the Past Decades

Coastal-trapped waves (CTWs) are a class of subinertial signals in the weather frequency band that play a pivotal role in coastal air-sea interaction. However, this important topic seems to be missing in the heated debate in recent years on coastal environmental change and protection. In this chapter, a brief but self-contained introduction of the CTW theory is presented, in the hope of providing a reference for investigators in the relevant fields. Also presented is a numerical scheme for computing the wave properties. As a demonstration, we have conducted a preliminary study of the CTWs for a section across the Subei Bank in the Yellow Sea. By the results, all the computed slow modes, including a bottom-intensified one, seem to be slowing down since two decades ago. They have particularly slowed down in the event when a strong El Niño is followed by a strong La Niña, such as in the 97–98 and 09–10 El Niño events

Nuclear Pollution in the East China Sea from the Fukushima Disaster

Nuclear pollution has become a new form and perhaps more harmful type of pollution that obsesses coastal regions; it has been of increasing concern after the disastrous Fukushima nuclear leak on March 11, 2011. In order to assess the impact of the Fukushima accident on the East China Sea (ECS), a highly resolved model is set up to simulate the evolution of the 137Cs concentration. Different from previous studies in this regard, here we take into account the radionuclides originally existing in the ocean. It is found that the radionuclides from the Fukushima leak do have reached ECS, though with a concentration far below the harmful level. The major waterways that inlet the radionuclides are Taiwan Strait and the waterway east of Taiwan. The radioactive material tends to accumulate in the ECS until reaching its peak in 2019; afterward, the outflux through Tokara Strait and Tsushima exceeds the influx through the two southern waterways, and the material resumes in 2021 to its original state. The concentration is neither homogeneously nor stationarily distributed; for example, usually in summer, there is a high center over the Subei Bank in the Yellow Sea. This study is expected, should a similar accident happen again, to help decide where to monitor the ocean, and, hopefully, how to get the pollution under control

The Cyclogenesis and Decay of Typhoon Damrey

The cyclogenesis of typhoons has been a continuing challenge in dynamic meteorology. In this study, we use a recently developed methodology, namely, multiscale window transform (MWT), together with the MWT-based localized multiscale energy and vorticity analysis and the theory of canonical transfer, to investigate the formation, maintenance, and decay of the typhoon Damrey, a rarely seen tropical storm of higher-latitude origin. The atmospheric fields are first reconstructed onto three scale subspaces or scale windows: large-scale window, tropical cyclone-scale window, and cumulus convection-scale window. On the cyclone-scale window, Damrey is found right along the edge of the subtropical high. It is generated due to a strong barotropic instability in the lower troposphere, but its subsequent rapid amplification is, however, related to a baroclinic instability in the upper troposphere. Damrey begins to decay before landfall, right over East China Sea at the mouth of Yangtze River, where a strong inverse cascade center resides and transfers the cyclone-scale energy backward to the large-scale window