A decade of acoustic thermometry in the North Pacific Ocean
A decade of acoustic thermometry in the North Pacific Ocean
复制标题
北太平洋声学测温十年
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
D. Menemenlis
中科院分区：
文献类型：
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作者：
B. Dushaw;P. Worcester;W. Munk;R. Spindel;J. Mercer;B. Howe;K. Metzger;T. Birdsall;R. Andrew;M. Dzieciuch;B. Cornuelle;D. Menemenlis
[1]在1996-2006年的十年间，位于加州中部（1996-1999年）和考艾岛北部（1997-1999年，2002-2006年）的声源传输到分布在整个东北和中北部太平洋的接收器。声波传播时间是固有的空间整合，抑制中尺度的变化，并提供了一个精确的测量射线平均温度。以4天为间隔的每日平均旅行时间提供了大规模热场的出色的时间分辨率。年际、季节和短期的变化很大，有时仅在几周内就发生重大变化。线性趋势估计在十年内是小的年际变化相比，路径路径不一致，一些声学路径略有升温，其他略有降温。将测得的传播时间与来自北太平洋四个独立估计的传播时间进行了比较：（1）气候学，如2005年世界海洋地图集（WOA 05）所示;（2）对来自卫星测高和现场剖面的上层海洋温度场的客观分析;（3）由喷气推进实验室实施的估算海洋环流和气候项目提供的分析（JPL-ECCO）;（4）并行海洋计划（POP）模式高分辨率配置的模拟结果。声学数据表明，WOA 05是一个更好的估计时间平均水文比JPL-ECCO或POP的估计，这两个被证明无法再现所观察到的声波到达模式。时间序列的比较提供了一个严格的测试模型中的大尺度温度变化。有时差异很大，表明声学测温数据可以为数值海洋模型提供重要的额外限制。
[1] Over the decade 1996–2006, acoustic sources located off central California (1996–1999) and north of Kauai (1997–1999, 2002–2006) transmitted to receivers distributed throughout the northeast and north central Pacific. The acoustic travel times are inherently spatially integrating, which suppresses mesoscale variability and provides a precise measure of ray-averaged temperature. Daily average travel times at 4-day intervals provide excellent temporal resolution of the large-scale thermal field. The interannual, seasonal, and shorter-period variability is large, with substantial changes sometimes occurring in only a few weeks. Linear trends estimated over the decade are small compared to the interannual variability and inconsistent from path to path, with some acoustic paths warming slightly and others cooling slightly. The measured travel times are compared with travel times derived from four independent estimates of the North Pacific: (1) climatology, as represented by the World Ocean Atlas 2005 (WOA05); (2) objective analysis of the upper-ocean temperature field derived from satellite altimetry and in situ profiles; (3) an analysis provided by the Estimating the Circulation and Climate of the Ocean project, as implemented at the Jet Propulsion Laboratory (JPL-ECCO); and (4) simulation results from a high-resolution configuration of the Parallel Ocean Program (POP) model. The acoustic data show that WOA05 is a better estimate of the time mean hydrography than either the JPL-ECCO or the POP estimates, both of which proved incapable of reproducing the observed acoustic arrival patterns. The comparisons of time series provide a stringent test of the large-scale temperature variability in the models. The differences are sometimes substantial, indicating that acoustic thermometry data can provide significant additional constraints for numerical ocean models.