The Chemical Hydrography of the South China Sea West of Luzon and a Comparison with the West Philippine Sea

南海在呂宋西側之化學水文及其與西菲律賓海之比較

龔國慶(Gwo-Ching Gong) ； 劉康克(Kon Kee Liu) ； 劉倬騰(Cho-Teng Liu) ； 白書禎(Su-Cheng Pai)

《Terrestrial, Atmospheric and Oceanic Sciences》 3卷4期 (1992/12) Pp. 587-602

摘要

本文報導1990年12 月在呂宋島西側之南海化學水文觀測結果，並與西菲律賓海相比較，以了解菲律賓海水進入南海後之變化情形及改變之原因。南海海水具有鹽度極大和極小值，以及南海深層水與西菲律賓海之相似性都顯示西菲律賓海水對南海之影響。然而，二海域的1500公尺以上的水，有很明顯的差異。南海的次表層水(100-600m) 較西菲律賓海同層的水來得冷，其所合之溶氧較同一溫度之西菲律賓海水來得少，而營養鹽來得多。然而，在中層水中( 600-1500m) 這種關係顛倒過來了。這些差異可以用來區分在二海域相接的界面區內，互相混合的水圈。南海次表層水之所以較冷且富合營養鹽，而海水特性之所以變化較小，除了垂直混合之外，尚可歸因於海水向上的流動，這種湧升可能與南海的深層水相當快速的替換有關。

並列摘要

The Chemical hydrography of the South China Sea west of Luzon observed in December, 1990 is reported and compared with that observed in the West Philippine Sea in October, 1990. The purpose is to understand the difference between the SCS water and its precursor, and how such change could be attained. The existence of salinity maximum and minimum in the South China Sea and the resemblance between the deep waters of the two seas reflected the influence of water intrusion from the West Philippine Sea to the South China Sea. On the other hand, distinctions in the water properties above 1500 m were found between the two seas. The subsurface water (100-600 m) of the South China Sea west of Luzon was considerably colder than that of the West Philippine Sea, and more enriched in nutrients and depleted in oxygen relative to the water of the same temperature in the western Philippine Sea. The situation was reversed in the intermediate water (600-1500 m). The salient features of our observations were supported by historical data, The chemical distinction between the two seas could be used to distinguish water masses in the interfacial zone. The much colder and nutrient-richer subsurface water and the uniformity in water properties in the South China Sea may be attributed to vertical mixing as well as upward advection, which was possibly related to rather rapid turnover of the deep water.