南海西沙海域的表层流特征

Surface Currents Characteristic in Xisha Area of the South China Sea

采用地震拖缆偏移羽角计算西沙海域西北的表层流，结果表明，研究区表层流沿北西一南东向运动，运动方向与潮汐运动相关。但在研究区东北存在一个由北西向东南单向流动的海流F1，F1受潮汐的影响顺潮时流速增大、逆潮时流速变小，F1可能是“东沙群岛北侧的一支偏西向海流”向西的一个分支；在研究区西南存在一个由东南向北西单向流动的海流砣，可能是南海西南表层流的一部分。

Surface current can be calculated from seismic streamer feather angle. Most of surface currents in Xisha area of the South China Sea flowed along the northwest-southeast and in connection with tidal movement, but there are two exceptions. One exception is current F1, it is an oneway flow （ F1 ） in the northeast of the study area, this current flowed from northwest to southeast, the velocity of F1 increased with the tide and decreased against the tide, F1 may be the one of currents which flowed to west in the north of Dongsha Islands. Another exception is current F2, it is also an one-way flow （F2） in the northeast of the study area, this current flowed from southeast to northwest, P2 may be part of the surface currents in the southwest of South China Sea.