Regime shift of the South China Sea SST in the late 1990s
Regime shift of the South China Sea SST in the late 1990s
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DOI：
10.1007/s00382-016-3178-4
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发表时间：
2016-05
期刊：
影响因子：
4.6
通讯作者：
B. Thompson;P. Tkalich;P. Malanotte‐Rizzoli
中科院分区：
文献类型：
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作者：
B. Thompson;P. Tkalich;P. Malanotte‐Rizzoli
利用观测资料和海洋再分析资料研究了1982-2014年中国南海海表温度的年代际变化。南海海温在20世纪90年代末出现了由冷到暖的突变。根据海温的长期变化，定义了冷暖两个时段，1982-1996年和2000-2014年，横跨1997-1999年南海变暖的两侧。尽管发生了强烈的厄尔尼诺增温事件，但海温异常在冷区趋于负值。相反，在暖区，正SST异常主导了拉尼娜驱动的冷却事件。冷(暖)海温状况以南海的净热量得(失)为标志。地面净热通量的长期变化主要受潜热通量异常的驱动，短波通量起次要作用。中国南海通海流的低频变化与南海海温的变化密切相关。南海夏季风在冷暖期表现出反转趋势。暖区减弱的南海热带气旋通过限制南海暖水向外流动，促进了南海变暖。同时，冷区海温增强是一种降温机制，导致持续的海温负距平。南海夏季风和海温的变化趋势与90年代末太平洋年代际振荡由暖位相向冷位相转换相吻合。
Decadal variability of the South China Sea (SCS) sea surface temperature (SST) during 1982–2014 is investigated using observations and ocean reanalysis datasets. The SCS SST shows an abrupt transition from a cold-to-warm regime in the late 1990s. Based on the long-term SST variability two epochs are defined, 1982–1996 and 2000–2014 as cold and warm regimes respectively, spanning on either side of the 1997–1999 SCS warming. Despite the occurrence of strong El Nino induced warming events, the SST anomalies tend to be negative in the cold regime. Conversely during the warm regime, the positive SST anomalies have dominated over the La Nina driven cooling events. The cold (warm) SST regime is marked by net heat gain (loss) by the SCS. The long-term variations of net surface heat flux are mainly driven by the latent heat flux anomalies while the short wave flux plays a secondary role. Low-frequency variability of the South China Sea throughflow (SCSTF) appears to be closely related to the SCS SST regime shift. The SCSTF shows reversing trends during the cold and warm epochs. The weakened SCSTF in the warm regime has promoted the SCS warming by limiting the outward flow of warm water from the SCS. Meanwhile, enhanced SCSTF during the cold regime acts as a cooling mechanism and lead to persistent negative SST anomalies. The change in trend of the SCSTF and SST regime shift coincides with the switching of pacific decadal oscillation from a warm to cold phase in the late 1990s.