摘要
夏季潜居于黄海深底层的冷水团(“黄海冷水团”),是我国近海水文特征中一个突出而重要的现象。有关这一冷水团的调查工作,日本学者早在1921年春就开始了;在北黄海的个别断面上,迄今已累积了一定数量而比较系统的资料。但就整个黄海而论,特别是南黄海,系统性的资料还很缺乏。
The cold water mass of the Yellow Sea and its circulation is an outstanding feature and constitutes one of the most important problems in the study of the oceanography of the China Sea.In this paper,the seasonal and secular temperature variations and the characteristics of the circulation are analyzed,using the historical hydrographical data of Dairen-C.Shantung Section,1928-1943.Its major topics are as follows:(1)The principal features of the seasonal variations of the temperature in the region of the cold water mass are investigated with the sectional distributions of temperature,its monthly deviation,and the amplitudes and phases of the annual temperature curves from ten years(1928-1937)averages.It is shown that the seasonal variations of the temperature mainly reflect the features of the thermal structure of the cold water mass in summer.(2)The secular variations of the temperature,the intensity of the front(main thermocline)in summer of the cold water mass,and their relations with the air temperature are studied using 13 years(1928-1931,1933-1940,1943)data.It is shown that the secular variations of the summer(Aug.)lowest temperature of the cold water mass are closely related to those of the winter(Jan.)mean air temperature in the neighbourhood area,while the secular variations of the intensity of the front in summer are related to those of the mean air temperature difference between summer and winter.These relations are helpful for the further study of the formation of the cold water mass as well as for the prediction of its temperature,and the latter has a practical significance for fisheries.(3)Simplefied formulas for calculations of the horizontal and vertical components of the velocity from temperature distribution are obtained.The formulas show that the distribution of the circulation of the cold water mass depends chiefly on the horizontal distribution of the vertically integrated temperature,it is,therefore,suggested that the summer circulation in the region of the cold water mass is largely due to thermal effect.Since the magnitude of the vertical velocity depends also on the value of the friction coefficient,if the magnitude of the latter is taken as the order of 10^(-5)sec^(-1),then the order of the vertical velocity is 10^(-3)cm sec^(-1),which agrees with the results obtained from the formula of Wyrtki.Furthermore,the relations between the circulation and the mass distribution of the cold water mass,the effect of the bottom friction and the vertical movement are briefly discussed in the light of Bjerknes’famous theory of the circular vortex.(4)Finally,the coefficient of the vertical eddy conductivity of cold water mass is determined by Fjelstad formula,the magnitudes obtained for the region near the main thermocline approximate to 1 cm^(2)sec^(-1),which agrees with the value generally accepted.
作者
管秉贤
KWAN PING-HSIEN(Institute of Oceanology,Academia Sinica)
出处
《海洋与湖沼》
1963年第4期255-284,共30页
Oceanologia Et Limnologia Sinica
