印度洋大眼金枪鱼和黄鳍金枪鱼渔场水温垂直结构的季节变化

摘要

In order to study the spatial distribution seasonal characteristic of the upper boundary depth, temperature of the thermocline and vertical temperature difference of the fishing ground of Thunnus obesus and Thunnus albacares in the Indian Ocean, the subsurface temperature and thermocline characteristics parameters were estimated based on temperature data of Argo profile floats from 2007 to 2010. Based on these basic work, the monthly distribution figures of the upper boundary depth, temperature of the thermocline and vertical temperature difference from 10 to 200 m were plotted. The topography of the upper boundary depth, temperature of the thermocline and vertical temperature difference from 10 to 200 m showed obvious seasonal variability. The variability of the upper boundary depth of the thermocline on the annual mode is very weak between the equator and 15°S zonal where the upper boundary depth of the thermocline is present very shallow throughout the year and large away from the equator in the Arabian Sea and the southern tropic Indian Ocean, there is a seasonal deep zonal of the upper boundary depth of the thermocline between 15°S and 25°S during May to September and a seasonal shallow zonal in the south of 20°S during December to April of next year. In generally, the upper boundary temperature of the thermocline is low where the upper boundary depth of the thermocline is deep. On the annual mode, the upper boundary temperature of the thermocline presents a warm-pool region in the southeastern of Arabian sea and the southwestern of Bay of Bengal during February to May and a lower temperature zonal in south of 20°S throughout year. The upper boundary depth of the thermocline is very deep between 15°S and 25°S during May to September so that the temperature variation between sea surface and the upper boundary depth of the thermocline is very large, the upper boundary temperature of the thermocline is very low. The variability of the upper boundary temperature of the thermocline topography is large in the south of 10°S and weak below the warm-pool region. The variability of temperature difference from 10 to 200 m, on the annual model is similar to the upper boundary temperature of the thermocline. The spatial distribution of vertical temperature difference is divided by 10°S longitude line. The temperature difference is lower than 10℃ in the south and it is greater than 10℃ in the north. The Analysis results reveal the spatial distribution seasonal characteristic of the upper boundary depth, temperature of the thermocline and vertical temperature difference in major tuna fishing ground of T. obesus and T. albacares in the Indian Ocean, which provide reference to long line production operation in sea of tuna.%为了解印度洋大眼金枪鱼(Thunnus obesus)和黄鳍金枪鱼(Thunnus albacares)主要作业渔场温跃层上界温度、深度和垂直温差时空变化特征,采用2007～2010年Argo温度剖面浮标资料,计算了印度洋大眼金枪鱼、黄鳍金枪鱼主要作业渔场次表层温度和温跃层特征参数.研究认为,温跃层上界深度、温度和10～200 m温差存在明显的季节性变化.5～9月在15°～25°S纬向区域存在一块季节性较深的温跃层上界深度区域;在20°S以南海域,12月至次年4月份温跃层上界深度非常浅;在15°S至赤道纬向区域,尤其是在西部,常年存在一块温跃层较浅的区域.总体而言,温跃层上界深度较深的地方温度相对较低,在2～5月期间,在阿拉伯海东南和孟加拉湾西南形成一块大面积的暖水区;7～9月期间,在15°～25°S,纬向区域因温跃层上界深度较深,从表层至温跃层上界深度温度变化相对较大,温跃层上界温度显著较低.在20°S以南,温跃层上界温度常年都很低.10°S经线方向将水下10 ～200 m垂直温度分成南北两部分,10°S以南部及以北部海区的垂直温差分别大于和小于10℃.分析结果初步揭示了金枪鱼主要作业渔场温跃层上界温度、深度和垂直温差分布特征,为金枪鱼实际生产作业提供理论参考.