Two‐layer tidal modeling of the Yellow and East China Seas with application to seasonal variability of the M₂ tide

Abstract

[1] The baroclinic response of tide and tidal currents in the Yellow and East China Seas is investigated using a two-layer numerical model. Seasonal variability in the M 2 tide, especially the smaller summer amplitudes prevailing along the Korea/Tsushima Strait [Kang et al., 1995], is investigated by a series of numerical experiments with varying degrees of stratification specific to winter and summer. Model results show that the summer amplitudes of the M 2 tide around the southwestern tip of the Korean peninsula and Korea/Tsusima Strait decrease, with a peak decrease of about 14 cm off the southwestern tip of the Korean peninsula, while the summer amplitudes in other coastal regions tend to increase. This seasonal variability generally coincides with the observations. These models results indicate that seasonal stratification has several noticeable effects on the tides, including varying degrees of current shear, varying frictional dissipation, and varying barotropic energy flux. In particular, it drives complicated seasonal variability in the M 2 tide, with a peak amplitude modulation of nearly 5% off the southwestern tip of the Korean peninsula. The seasonal variation of barotropic M 2 energy flux through the eastern entrance of the Yellow Sea is thought to induce the corresponding variability in the M 2 amplitude in the Korea/Tsusima Strait, with smaller amplitudes found in the summer.

Temperature correction and usefulness of ocean bottom pressure data from cabled seafloor observatories around Japan for analyses of tsunamis, ocean tides, and low-frequency geophysical phenomena

“…However, tidal analyses have suggested that the TM1 and KPG2 data could be used to study temporal variations of tidal constituents in excess of 1 hPa, even though they are a little noisier than the Paros data. The tidal constituents are known to change seasonally (e.g., Kang et al, 2002), interannually (e.g., Munk et al, 1965), and secularly (e.g., Ray, 2006, and references therein) although their mechanisms are still poorly understood. Even the theoretically expected 18.6-year nodal modulation has recently been paid attention in relation to bi-decadal climate changes (e.g., Osafune and Yasuda, 2006;Ray, 2007).…”

“…Seasonal variations of ocean tides have been reported in terms of sea level by a number of studies (e.g., Tamura, 1985;Pugh, 1987;Kang et al, 1995Kang et al, , 2002Leeuwenburgh et al, 1999;Blanton et al, 2004) and, in spite of limited studies, in terms of OBP (e.g., Tamura et al, 1986;Blanton et al, 2004). Tamura et al (1986) used the OBTM data of JMA (Isozaki et al, 1980) and pointed to a seasonal variation of the M 2 constituent, without detailed discussions.…”

“…Blanton et al (2004) used sea level and OBP data, and noted a seasonal variation of the M 2 constituent of the sea level, but hardly described the seasonal variation of the OBP tide because of the short duration of the observations. Although the effects of stratification (Kang et al, 2002) and tide-surge interaction (e.g., Pugh, 1987;Leeuwenburgh et al, 1999;Bernier and Thompson, 2007) have been suggested as causes of the seasonal variation of ocean tides in coastal regions, critical mechanisms have not yet been proposed (Woodworth, 2010). Although, investigating the mechanism of the seasonal modulation of ocean tides is beyond the scope of the present study, we assume that the seasonal variations of the OBP tide should be observed ubiquitously and their detectability is regarded as a measure of the quality of the OBP data at the tidal frequency bands.…”

A survey of recent changes in the main components of the ocean tide

“…For example, the fact that tidal constants vary seasonally has been known for many years but the reasons for such variations, which occur especially in shallow waters (e.g. Pugh and Vassie, 1992;Kang et al, 2002) and at high latitudes (e.g. Prinsenberg, 1988;Kagan and Sofina, 2009), remain poorly understood.…”

Sea level rise impact in residual circulation in Tagus estuary and Ria de Aveiro lagoon

“…There have been many results about tide modeling in Chinese Sea ( Bao et al, 2001;Fang et al, 2004;Kang et al, 2002;Lefèvre et al, 2000;Song et al, 2013;Wang et al, 2014;Yao et al, 2012;Yu et al, 2003 ) . Some Chinese scientists have studied the effects of SLR on Chinese Sea ( Kuang et al, 2014;Yu et al, 2003Yu et al, , 2007 , but the conclusions were not consistent, especially the changes of tidal range and phase lags in local Bohai Sea.…”