| The South China Sea. is a marginal sea, largely surrounded by land, and possesses some characteristics of coastal and open sea. The topography and the physiognomy of the South China Sea are very complex such as continental slop, continental shelves, seamounts, sea basin, etc. The South China Sea lies between Qingzang plateau, which is as the main driver of the variety of climate, and the western part of the pacific, which is called warm pool, and is influenced by some current systems, such as coastal current, Kuroshi, etc. The South Sea has considerable species. All of these reasons as above affect the distribution, transportation and transference of biogenic elements in the South China Sea.A lot of data had been obtained during the two cruises of oceanographic research in the South China Sea (5 00 ' -23 00 ' N, 108 00 ' - 119 30 ' E) in June and Nov, 1998. On the base of investigation, some researches had been done in this report.1. Discussing the rules of horizona1 section and vertical distribution about DO,pH,NO3-.. NO2 NH-4 P043- and SiO32- , and making researches on the temporal and spacial distribution and characteristics of these biogenic elements in the South China Sea. 2. Statistical analyses used to classify the water mass in vertical direction and the characteristic values of these biogenic elements in different water mass obtained. 3. Some theories or means, such as box model, one-dimensional advection-difusion models, applied to study on the transportation and the relaionship of biogenic elements. The results show that:(1) The variational rules of these biogenic elements in the South China Sea had been summarized.(2) Surface (0-75m) , hyposurface (75-300m) , intermediate (300-1000m) and deep ( 1000-3000m) water mass can be classified in vertical direction.(3)Box model results indicate that the net flux of suface water, flowing into the South China Sea, is about 8.364X 106T/s and the net flux of water, which is under suface water, flows out of the South China Sea at about 8.229X 106T/s on annual average.The quantity of DIN, reactive phosphate or reactice silicate, which sinked into deep water in the form of particle matter, was about 78, 71 and 80 percent of total quantity of DIN, reactive phosphate and reactive silicate, which flowed into suface water in any ways. But in these particle matters, ahout2.9 percent of particle nitrogen, 2.0 percent of particle phosphor and 8.2 percent of particle silicon sinked into sediment.(4) the South China Sea can been view as the source of atmospheric oxygen, the flux of oxygen into atmosphere is about 0.048 mol m-2 d-1 in summer and about 0.015mol m-2 d-1 in winter, the value of annual average is about 0.032mol m-2 d-1(5) the ratio of △O,△Si,△N and AP is about 276:53:21:1.5 in summer and about276:47:18.5:1.2 in winter. The ratios are close to the Redfield ratio.(6) the supplement of oxygen,which was used during remineralization, was due to the mix of different water mass in vertical direction, and the gradient variation of nutrients resulted from the remineralization of organic matter in hyposurface and intermediate water mass.(7) the consumption rates of oxygen was about 0. 33 #0. 13$mol/dm3a in summer and about 0.26#0.08$mol/dm3-a in winter, and was about 0.30 # 0.08$mol/dm3-a on annual average, and the production rates of nitrate was about 0. 033 # 0. 024$mol/dm3-a in summer and about 031 # 0.015 $mol/dm3-a, and was about 0.032 # 0. 021$mol/dm3-a on annual average, and the production rates of phosphate was about 0.0026 # 0.0018 in summer and aout 0.0034 # 0. 0018$,mol/dm3-a, and was about 0.0030 # 0. 0018$mol/dm3-a on annual average in deep water, in 1998. The quantity of nitrate or phosphate produced during reminerlization was about 3.45 percent of total quantity of nitrate and 4.40 percent of total quantity of phosphate in deep water.These results can make us know the distribution and characteristics of biogenic elements in the South China Sea all-around, and of... |
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