Towards determining uncertainties in global oceanic mean values of heat, salt, and surface elevation
Towards determining uncertainties in global oceanic mean values of heat, salt, and surface elevation
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确定全球海洋热、盐和表面海拔平均值的不确定性
DOI：
10.1080/16000870.2018.1471911
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
C. Wunsch
中科院分区：
文献类型：
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作者：
C. Wunsch
摘要在1994-2013年的数据密集期内，计算了海洋数据和模型的不确定性下限，以及海洋温度、盐度和海面高度的20年时间平均值及其时间演变。通过抑制场的全局相关分量，探索了将场的随机性与系统性或确定性元素分离的重要步骤。理由在于物理学和相对于整个海洋调整时间的20年估计的简短性，以及推断的短时间间隔内的响应接近线性。反映状态估计的唯一随机元素的下限不确定性，然后从自助估计计算。趋势估计为海拔0.0011 ± 0.0001 °C/y，地表海拔、温度和盐量为（−2.825 ± 0.17）× 10−5，形式上有2个标准差的不确定性。温度变化对应于20年平均海洋加热率W/m2，其中0.1 W/m2来自地热强迫。系统误差必须单独确定。
Abstract Lower-bounds on uncertainties in oceanic data and a model are calculated for the 20-year time means and their temporal evolution for oceanic temperature, salinity, and sea surface height, during the data-dense interval 1994–2013. The essential step of separating stochastic from systematic or deterministic elements of the fields is explored by suppressing the globally correlated components of the fields. Justification lies in the physics and the brevity of a 20-year estimate relative to the full oceanic adjustment time, and the inferred near-linearity of response on short time intervals. Lower-bound uncertainties reflecting the only stochastic elements of the state estimate are then calculated from bootstrap estimates. Trends are estimated as in elevation, 0.0011 ± 0.0001 °C/y, and (−2.825 ± 0.17) × 10−5 for surface elevation, temperature and salt, with formal 2-standard deviation uncertainties. The temperature change corresponds to a 20-year average ocean heating rate of W/m2 of which 0.1 W/m2 arises from the geothermal forcing. Systematic errors must be determined separately.