The article presents the studied results of Sub-project 2 of the cooperation between Vietnam and Russia in the survey and research of East sea, based on analysis of synchronous measurements of the physical and ecological environmental elements during the transfer season in the continental shelf waters of Khanh Hoa province. The results can be summarized as follows: From the maps of the spatial distribution of the, temperature and salinity at the depth layers, saw a clear division between the cold water and hot water masses. The dividing line between the water masses, also known as the front line is determined at the distance about 2030km from shore. The cold water is formed near the shore by the cold flow during the Northeast monsoon, with the low temperatures, high salinity and moves from North to South. During the period of April-May, in the waters of Khanh Hoa province, although this cold flow was weakened, but still influence in the surface layers to the depth of 25-30m. The hot water is formed in the off-shore by the flow of the warm, waters from the southern regions of East Sea, this water mass with the high temperature and low salinity. From the depth of 30 to 70m, the trend in the distribution of the temperature and salinity is complicated change, has demonstrated the clear disruption and strong dispute between the hot and cold water mass, this is the junction with a strong variation of the temperature and salinity. From the depth of 70m to the bottom, the distribution of temperature and salinity fields has the tend to reduce the temperatlire and increase the salinity in the direction from the shore out to sea; Turbidity of seawater in the survey area tended to decrease from the coast to the sea and increases from the surface to the bottom. In the area near the building works of the oil entrepot port at the mouth of Van Phong bay, sea turbidity strongly influenced and increased high; Depth of the fast changed layers of the temperature and salinity are likely that increases from the shore out to sea, from depths of 15m to 35m, while the thickness of their is about 30-35m. In the fast changed layers of the temperature and salinity, the eco-environmental factors, such as dissolved oxygen, chlorophill_a have the maximum value; At the depth of 80-90m, has the water layer with the minimum value of dissolved oxygen; As in the strong interaction of hot and cold water masses, the fine structures of the elements are formed fairly common, ie from the depth of 20-60m, formed the layers with the different small sizes, which causes by the stratosphere of hot and cold flows; Structure in the vertical distribution of the sound speed have the form of plus. refraction with type II, this the structure of sound transmission in the ocean based on the multiple reflections of the sound beam on the sea surface and boltom surface.
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21,978,154
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