利用南大洋漂流浮标数据评估AMSR-E SST

Evaluation of AMSR-E SST in the Southern Ocean using drifting buoy data

利用AOML(Atlantic Oceanographical and Meteorological Laboratory)SVP漂流浮标的海表面温度数据,针对30°S以南的南大洋海域,对目前主要使用的微波遥感产品(AMSR-E,Ad-vanced Microwave Scanning Radiometer for the Earth Observing System)反演的SST进行了较为系统的评估。结果表明,AMSR-E SST比浮标数据偏冷,偏差为-0.01℃,标准差为0.70℃。夏季的偏差为0.004℃,标准差为0.64℃;冬季的偏差为-0.06℃,标准差为0.75℃,冬季的偏差和标准差较大。温差ΔT受流速影响,随着流速的增大而减小,且这种趋势在夏季更为显著。具备托伞结构的浮标与总体情况基本一致,而无托伞结构的浮标受流速的影响要大一些。同时,温差ΔT受水汽的影响,随着水汽的增加而减小,且这种影响在冬季更大一些。进一步对4个穿极和绕极浮标的追踪分析表明,温差ΔT受大洋海流系统的影响显著。在海流大的大西洋边界流和南极绕极流中,温差ΔT的不确定性要明显大于总体情况。

This study evaluated the microwave remote sensing SST derived from AMSR-E（Advanced Microwave Scanning Radiometer for the Earth Observing System） using AOML（Atlantic Oceanographical and Meteorological Laboratory） SVP drifting buoy data,focusing on the Southern Ocean（south of 30°S）.Compared to the buoy data,AMSR-E has a mean bias of-0.01 ℃（0.004 ℃ for summer and-0.06 ℃ for winter） and standard deviation（STD） of 0.70 ℃（0.64 ℃ for summer,and 0.75 ℃ for winter）.The biases of AMSR-E SST（ΔT） are influenced by ocean surface velocity,particularly decreasing with the increasing velocity in summer.The drogued data shows similar results to that of all data,but the undrogued data is more significantly influenced by the velocity.Also,the biases of AMSR-E SST are influenced by water vapor,particularly decreasing with the increasing water vapor in winter.Further analyses of tracing four buoys crossing or following the Antarctic circumpolar current suggest that the SST bias is influenced by the ocean current systems.The SST uncertainty is much larger than that of overall circumstances.