东太平洋我国开辟区底层海流锚泊观测

MOORING OBSERVATION OF BOTTOM SEA CURRENT IN THE CHINA PIONEER AREA,EASTERN PACIFIC OCEAN

“海洋四号”在执行ＤＹ９５－７和ＤＹ９５－９航次调查任务期间，在东太平洋我国开辟区做了２个测站的底层海流观测。观测资料分析表明，底层流的流速在１．２～１２．０ｃｍ／ｓ之间；底层流有月际和日际变化，并发现底层流存在“不活动”期。

Mooring observation of bottom sea current was done at the 2 stations in the China pioneer area of East Pacific Ocean during “Haiyang 4”cruises DY95 7 and DY95 9.This report presents the analyzed and studied results of mooring observation of deep sea bottom current.Data analyses show that:the current velocity is 1 2～12 0 cm/s,among which,velocity 200 m from the seafloor is generally 1 3～12 0 cm/s,and 8 m from the seafloor generally between 1 2 and 10 0 cm/s.Bottom current not only has changes in months,days and low frequency period of 20～30 days,but also has an“unactive”period.In the layer 200 m from the seafloor,the“unactive”period of the current is taking 1 day as the shortest and 6 days as the longest;8 m from the seafloor,the shortest is 1 day and the longest 8 days.The largest velocity occurs in August,and the smallest in July.And the velocity changes most frequently in April and October.Except January and November,all the months see a larger velocity 200 m from the seafloor than that 8 m from it.The direction of the bottom current is nearly opposite in January to that in June.