Global and Full-Depth Ocean Temperature Trends during the Early Twenty-First Century from Argo and Repeat Hydrography
Global and Full-Depth Ocean Temperature Trends during the Early Twenty-First Century from Argo and Repeat Hydrography
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DOI：
10.1175/jcli-d-16-0396.1
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发表时间：
2017-03-01
影响因子：
4.9
通讯作者：
Thierry, Virginie
中科院分区：
文献类型：
--
作者：
Desbruyeres, Damien;Mcdonagh, Elaine L.;Thierry, Virginie
通过将Argo（顶部2000 m）分析和重复水文学结合到混合的全深度观测系统中，计算了21世纪初全球全深度海洋的变暖趋势。世纪初全球海洋的变暖趋势。在过去十年的持续观测中，地表到海底的温度变化相当于地球表面的0.71 +/- 0.09Wm（-2）的热吸收，其中90%在2000米以上的深度。作者将温度趋势逐点分解为等密度线深度（起伏）的变化和温度沿着等密度线（辣味）的变化，以描述控制变化的机制。垂荡分量在全球热含量增加中占主导地位，在南半球的热带外（0-2000米）发现的最大趋势突出了亚热带模式沃茨的体积增加。在北大西洋和南大洋深处（2000-4000米）也发现了与升沉有关的显著变暖，反映了深水质量更新率的潜在下降。辛辣成分在中层（700-2000米）显示出最强的贡献，在强烈垂直混合的区域（北大西洋和南大洋）具有显著的局部变暖信号。最后，在2000米的独立阿尔戈和重复水文温度变化之间的协议提供了一个整体良好的信心，在全球和海洋尺度上的混合热含量评估，但也突出了流域规模的差异，两个独立的估计。这些不匹配是最大的那些盆地最大的起伏签名（南大洋），并反映了时间和空间稀疏的水文采样。
The early twenty-first century's warming trend of the full-depth global ocean is calculated by combining the analysis of Argo (top 2000 m) and repeat hydrography into a blended full-depth observing system. The surface-to-bottom temperature change over the last decade of sustained observation is equivalent to a heat uptake of 0.71 +/- 0.09Wm(-2) applied over the surface of Earth, 90% of it being found above 2000-m depth. The authors decompose the temperature trend pointwise into changes in isopycnal depth (heave) and temperature changes along an isopycnal (spiciness) to describe the mechanisms controlling the variability. The heave component dominates the global heat content increase, with the largest trends found in the Southern Hemisphere's extratropics (0-2000 m) highlighting a volumetric increase of subtropical mode waters. Significant heave-related warming is also found in the deep North Atlantic and Southern Oceans (2000-4000 m), reflecting a potential decrease in deep water mass renewal rates. The spiciness component shows its strongest contribution at intermediate levels (700-2000 m), with striking localized warming signals in regions of intense vertical mixing (North Atlantic and Southern Oceans). Finally, the agreement between the independent Argo and repeat hydrography temperature changes at 2000m provides an overall good confidence in the blended heat content evaluation on global and ocean scales but also highlights basin-scale discrepancies between the two independent estimates. Those mismatches are largest in those basins with the largest heave signature (Southern Ocean) and reflect both the temporal and spatial sparseness of the hydrography sampling.