Revisiting the contemporary sea-level budget on global and regional scales
Revisiting the contemporary sea-level budget on global and regional scales
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DOI：
10.1073/pnas.1519132113
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发表时间：
2016-02-09
影响因子：
11.1
通讯作者：
Dahle, Christoph
中科院分区：
文献类型：
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作者：
Rietbroek, Roelof;Brunnabend, Sandra-Esther;Dahle, Christoph
将海平面预算划分为冰盖和冰川的贡献，水循环，空间扩张和地壳运动是具有挑战性的，特别是在区域尺度上。在这里，重力恢复和气候实验（GRACE）重力观测和测高的海平面异常被用于联合反演，确保全球和区域海平面上升预算的一致分解。在2002-2014年期间，我们发现全球平均空间趋势为1.38 +/- 0.16 mm/y，而总趋势为2.74 +/- 0.58 mm/y。这是显着大于从原位温度/盐度剖面和模型，从0.66 +/- 0.2至0.94 +/- 0.1毫米/年范围内得出的空间趋势。冰盖和冰川的质量贡献（1.37 +/- 0.09 mm/y，以0.03 +/- 0.02 mm/y加速（2））被负水文分量（-0.29 +/- 0.26 mm/y）抵消。综合质量速率（1.08 +/- 0.3 mm/y）小于GRACE之前的估计值（高达2 mm/y），但与文献中发现的单个贡献（冰盖，冰川和水文）的总和一致。高度海平面收支通过共估剩余分量0.22 +/- 0.26 mm/y来闭合。在菲律宾（14.7 +/- 4.39 mm/y）和印度尼西亚（8.3 +/- 4.7 mm/y）附近发现了远高于平均海平面的区域性上升，这主要是空间分量（分别为11.2 +/- 3.58 mm/y和6.4 +/- 3.18 mm/y）。相比之下，在太平洋中部和东部，检测到负空间趋势（降至-2.8 +/-1.53毫米/年）。发现了重要的区域成分，西北大西洋高达5.3 +/- 2.6毫米/年，这可能是由于洋底压力的变化。
Dividing the sea-level budget into contributions from ice sheets and glaciers, the water cycle, steric expansion, and crustal movement is challenging, especially on regional scales. Here, Gravity Recovery And Climate Experiment (GRACE) gravity observations and sea-level anomalies from altimetry are used in a joint inversion, ensuring a consistent decomposition of the global and regional sea -level rise budget. Over the years 2002-2014, we find a global mean steric trend of 1.38 +/- 0.16 mm/y, compared with a total trend of 2.74 +/- 0.58 mm/y. This is significantly larger than steric trends derived from in situ temperature/salinity profiles and models which range from 0.66 +/- 0.2 to 0.94 +/- 0.1 mm/y. Mass contributions from ice sheets and glaciers (1.37 +/- 0.09 mm/y, accelerating with 0.03 +/- 0.02 mm/y(2)) are offset by a negative hydrological component (-0.29 +/- 0.26 mm/y). The combined mass rate (1.08 +/- 0.3 mm/y) is smaller than previous GRACE estimates (up to 2 mm/y), but it is consistent with the sum of individual contributions (ice sheets, glaciers, and hydrology) found in literature. The altimetric sea -level budget is closed by coestimating a remaining component of 0.22 +/- 0.26 mm/y. Well above average sea -level rise is found regionally near the Philippines (14.7 +/- 4.39 mm/y) and Indonesia (8.3 +/- 4.7 mm/y) which is dominated by steric components (11.2 +/- 3.58 mm/y and 6.4 +/- 3.18 mm/y, respectively). In contrast, in the central and Eastern part of the Pacific, negative steric trends (down to -2.8 +/- 1.53 mm/y) are detected. Significant regional components are found, up to 5.3 +/- 2.6 mm/y in the northwest Atlantic, which are likely due to ocean bottom pressure variations.