Position messages from ALACE float DP21

Data have been checked by the WOCE Subsurface Float Data Assembly Center. See hdl:10013/epic.32931.d001 for further information.本数据集已由世界海洋环流实验（World Ocean Circulation Experiment）水下浮标数据组装中心完成质量核验。如需获取更多详细信息，请参见hdl:10013/epic.32931.d001。