Seasonal evolution of the Yellow Sea Cold Water Mass and its interactions with ambient hydrodynamic system

Abstract

The Yellow Sea Cold Water Mass (YSCWM) is an important component of the hydrodynamic system in the South Yellow Sea (SYS). However, its intricate interactions with the ambient flows over long time scales are not fully understood. This paper presents the analysis of the data set obtained from a seabed‐mounted Acoustic Doppler Current Profiler (ADCP) deployed for nearly 1 year in the western SYS. It allowed us to study the evolution of YSCWM, including the seasonal changes of tidal currents, near‐inertial oscillations (NIOs), and the wind‐driven currents due to typhoons and winter storms. Strong NIOs were found near the bottom of mixed layer and in the pycnocline with nearly opposite current directions, with maximum velocity of nearly 20 cm·s−1 in summer. The YSCWM can also inhibit the direct downward energy transport in the water column due to typhoons. Conversely, the hydrodynamic system also feeds back to influence the change of YSCWM. A large current shear (S) of 20 cm·s−1·m−1 is generated near the top of pycnocline. Generally, the intensity and depth of the pycnocline determine S's magnitude and vertical location, respectively. Based on the monthly averaged density profile data, the Richardson number and wavelet analysis, the NIOs are considered to be capable of inducing predominant shear instability around the pycnocline. However, the NIOs are not strong enough to influence the lower YSCWM. In addition, in autumn, each fortnightly spring tide corresponds with a bottom temperature increase of nearly 2°C, indicating that tidal currents are the leading hydrodynamic driving force to decline the YSCWM.

Influence of thermal stratification and storms on acoustic telemetry detection efficiency: a year-long test in the US Southern Mid-Atlantic Bight

“…As Cold Pool presence in the SMAB can be broadly represented by large differences between surface and bottom water temperatures [17,18], we utilized the difference between satellite-derived sea surface temperature and in-situ receiver-recorded bottom water temperature as an index of temperature strati cation associated with the Cold Pool. In addition to the SMAB, this metric, ΔT, has previously been used as an index of thermal strati cation in other systems [2,48]. Multi-scale Ultra-high Resolution Sea…”

Nitric oxide (NO) in the Bohai Sea and the Yellow Sea

“…Nitric oxide (NO) is a short-lived intermediate of the oceanic nitrogen cycle (Bange, 2008). It received limited attention so far because its determination in seawater is challenging (Zafiriou and McFarland, 1980;Lutterbeck and Bange, 2015;Liu et al, 2017). NO in surface seawater can be produced via the photolysis of nitrite (NO − 2 ) (Zafiriou and McFarland, 1981;Olasehinde et al, 2009Olasehinde et al, , 2010Liu et al, 2017):…”

“…The current understanding of the oceanic NO distribution is mainly limited to the ocean surface (Zafiriou and McFarland, 1981;Olasehinde at al., 2009Olasehinde at al., , 2010Liu et al, 2017) and oxygen minimum zones (OMZs; Ward and Zafiriou, 1988;Lutterbeck et al, 2018). Only recently have the distribution of NO as well as its seasonal variation in the Jiaozhou Bay and adjacent waters been studied (Feng et al, 2011;Xue et al, 2012;Tian et al, 2016).…”

Diurnal Forcing Induces Variations in Seasonal Temperature and Its Rectification Mechanism in the Eastern Shelf Seas of China

“…A comparison of the Diurnal and Daily Cases shows that a large deviation occurs in the summertime bottom temperature (Figure k) in the central Yellow Sea that overlaps with the area of the YSCWM. The YSCWM is a bottom water mass with relatively low temperature below the strong thermocline in the central Yellow Sea from May to November and is usually bordered by a 10 isotherm (Fei et al, ; Li et al, ; Zhang et al, ). The mean temperature of the YSCWM from May to November was 8.9 in the Diurnal Case but was 8.5 in the Daily Case (Table ).…”