摘要
就 1998年 2— 3月台湾海峡AVHRR表层水温和SeaWiFS叶绿素数据以及当年 2月 2 0日至 3月 8日在台湾海峡北部海区所实施的多学科现场调查资料进行综合分析 ,着重探讨暖水入侵的过程及其生态响应。结果表明 ,1998年冬季由澎湖水道北上进入台湾海峡的高温高盐黑潮入侵水强度大于往年 ,在 2月 8日— 3月 13日期间不断增强 ,直至侵占整个海峡东侧海域 ,迫使低温低盐且富含营养盐的闽浙沿岸水主流顺大陆沿岸南下。这一过程向海峡西侧海域输入营养盐并使之达到适宜的水温 ,极可能是西侧海域出现叶绿素高值区、呈现出与往年相反的叶绿素分布态势的主控机制。分析这一现象与 1997— 1998年的E1Nino事件可能存在着某种关联。
Taiwan Strait is a shallow shelf channel linking the East China Sea (ECS) and the South China Sea (SCS). During winter monsoon, cold Min-Zhe Coastal Water (hereafter MZCW) rich of nutrients generally dominates the northern Taiwan Strait; warm oligotrophic Kuroshio water (hereafter KW) and Soiuth China Sea Water (hereafter SCSW) from SCS intrude into the southern Taiwan Strait. Nevertheless, Kuroshio intrusion into the Taiwan Strait was found to be stronger than usual during winter monsoon of 1998, as observed by a satellite instrument, AVHRR, and a CTD in situ. In situ data were obtained in the northern Taiwan Strait during a winter cruise of 1998 from February 20th to March 8th, which suggested that warm streamer as indicated by 18℃ isotherm approached as north as 26°N. A series of AVHRR SST daily images covering the whole Taiwan Strait region, which were got on Feb.8th, Feb.25th and Mar.13th, respectively, confirmed that warm water mainly intruded into the Taiwan Strait from the southernmost tip of Taiwan, heading northeastward along the Penghu Channel. There were also some evidences hinting that warm water coming from the Kuroshio mainstream off Taiwan in the Pacific ocean, intermittently influenced the northern Taiwan Strait from the northernmost tip of Taiwan. This effect seemed to be weakening while the northeastward Kuroshio intrusion was strengthening from February to March. The mainstream of Min-Zhe Coastal Water was thus forced to go southwestward along the Mainland coast into the southern Taiwan Strait. This process probably heated Min-Zhe Coastal Water and led to the injection of nutrients into the southern Taiwan Strait, enabling unusual high winter Chla along the Mainland coast, especially in the southwestern Taiwan Strait, as shown by a single SeaWiFS Chla imagery on March 27th. Observation in situ from February to March also confirmed Chla enhancement in the northwestern Taiwan Strait. Chla content reached as high as ca. 5 mg/m+3, which were 4 times greater than that was observed in 1995. It was suspected that the unusual strong Kuroshio intrusion and the corresponded Chla enhancement in the Taiwan Strait during winter 1998 were probably related to the very strong tropic E1 Nino of 1997～1998.
出处
《遥感学报》
EI
CSCD
北大核心
2001年第5期383-387,T007,共6页
NATIONAL REMOTE SENSING BULLETIN
基金
国家自然科学基金重点项目 496362 2 0
国家自然科学基金 4990 60 0 8资助
