中文摘要：

基于2012年10月和12月两次南海北部走航ADCP和站位CTD等资料,分析了南海北部海流的流速结构和温盐特征。通过校正ADCP失准角,将ADCP流速测量精度控制在5 cm/s,并得到两个航次7个断面的流速数据。走航ADCP成功地观测到了南海西边界流和南海暖流,其中西边界流流幅和厚度分别为120 km和200 m,顺风流向西南,最大流速和流量范围分别为30～67 cm/s和0.74～9.70 Sv（1 Sv=106m3/s）;而暖流流幅和厚度分别为40 km和600 m,呈带状结构,逆风流向东北,最大流速和流量范围分别为12～18 cm/s和0.14～1.13 Sv。对海南岛东部同一断面不同时间的两次观测表明,海流的流速结构发生了一定的变化,10月观测时西边界流和暖流分别位于陆架附近的表层和陆坡附近200 m以深的次表层,而12月观测时暖流出现在陆架附近表层到800 m以深的全深度范围,西边界流则分布于暖流南北两侧。在海南岛南部17.1°N、109.9°E附近观测到有暖流通过,此暖流的位置是迄今为止所有报道中的最西侧。

英文摘要：

The characteristics of current velocity and structures of temperature and salinity were evaluated by the shipboard ADCP（ Acoustic Doppler Current Profiler） and CTD（ Conductivity Temperature Depth） data collected during two cruises in the northern South China Sea（ SCS） in October and December of 2012.The accuracy of shipboard ADCP velocity was controlled within 5 cm/s by the corrected misalignment angle,and current velocity data of were obtained at seven sections from the two cruises.The SCS western boundary current and warm current were successfully observed by the shipboard ADCP survey.The SCS western boundary current was flowing southwestward downwind with a width of 120 km and a vertical range of 200 m with the maximum velocity from 30 cm/s to 67cm/s and from 0.74 Sv to 9.70 Sv（ 1 Sv = 106m3/s）.The warm current,however,was flowing northeastward upwind with a horizontal and vertical ranges of 40 km and 600 m,with the maximum velocity of 12-18 cm/s and0.14-1.13 Sv.The two cruises revealed that there were some changes in the velocity structure in the same section of east Hainan Island.In October,the western boundary current and warm current were located in the surface layer near the shelf and below 200 m near the slope,while the western current was divided into northern and southern branches by the warm current which located in depth from surface to 800 m depth.Moreover,the warm current was found in south of Hainan Island near 17.1°N,109.9°E,and is until now the most westwards.