Effects of the Yellow Sea Warm Current on the winter temperature distribution in a numerical model

Abstract

[1] The temperature distribution and circulation patterns in the Yellow Sea (YS) are examined by using a wave-tide-circulation coupled numerical model. This model sufficiently reproduces the variation of the warm tongue structure of the Yellow Sea Warm Current (YSWC) from the double branches flowing along the YS Trough and the western 60 m isobath in January to the single stream along the western temperature front in March. This is observed in both the long-term monthly climatology and the satellite-based sea surface temperature images in recent years. Examining the local heat balance in the numerical model during the entire cooling period, it is found that the YSWC has a very important influence on the YS warm tongue structure. Compared with the surface cooling, the influence of the advection is small in the coastal shallow area but large in the deep warm tongue area (up to 50% of the magnitude of heat flux). Although bathymetry is the essential factor which causes the temperature front, the YSWC is the key factor which positions, shapes, and maintains the warm tongue structure. This helps to affirm the existence of the YSWC, at least as a monthly mean flow. However, more high-resolution current observations in deeper layers west of Cheju Island and the western fork of the YS Trough are needed to confirm the existence of the YSWC and its characteristic timescale in the real YS.

Winter heat budget in the Huanghai Sea and the effect from Huanghai Warm Current (Yellow Sea Warm Current)

“…This horizontal distribution of net SHF from the above data sets is different from the work of Ma et al (2006) which showed the largest negative net SHF in the central HS. Their calculation was made by using a simple atmospheric feedback scheme (Harney, 1971), though their results were integrated from October to March.…”

“…Although there were some minor differences in their minimum value, all data sources from this study exhibited the same trend in the net SHF variation in the shallow water and warm tongue area, with the largest surface cooling occurred in December. However, according to Ma et al (2006), the lowest value in the shallow water described was in October (Fig. 13a in Ma et al, 2006), while in the warm tongue area, the net SHF reached a minimum value in January.…”

“…Huang et al (2005) pointed out that both surface cooling and advection of the current play an important role in the formation of the tongue in the winter. Ma et al (2006) concluded that the bathymetric effect was a large contributor in forming the temperature gradient, while the HWC was also an important factor in determining the warm tongue's structure and position.…”

Long-term variation in the salinity of the Southern Yellow Sea Cold Water Mass, 1976–2006

“…Lv et al (2009) found that the winter salinity of the northern YS at depths of 0, 10, and 20 m has shown an increase since the 1950s. Similarly, Ma et al (2006) reported that the mean salinity of the Dalian-Chengshantou section was increasing. Jiang et al (2007) analyzed the bottom salinity of a station at the center of the Dalian-Chengshantou section and found no clear salinity changes in the NYSCWM.…”

“…The salinity trend of the coastal area is positive and may be related to the coastal current from the northern YS. The salinity of the water (Lin et al 2001;Ma et al 2006;Lv et al 2009). Wu et al (2004) concluded that the sustained and rapid reduction in Yellow River runoff was a major reason for the increased salinity in the Bohai Sea.…”