Estimating Sea Surface Temperature Measurement Methods Using Characteristic Differences in the Diurnal Cycle
Estimating Sea Surface Temperature Measurement Methods Using Characteristic Differences in the Diurnal Cycle
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DOI：
10.1002/2017gl076475
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发表时间：
2018-01-16
影响因子：
5.2
通讯作者：
Kent, E. C.
中科院分区：
文献类型：
--
作者：
Carella, G.;Kennedy, J. J.;Kent, E. C.
缺乏可靠的观测元数据是理解海表温度（SST）测量偏差的一个关键障碍，这是全球表面记录不确定性的一个重要因素。我们提出了一种方法来确定SST测量实践中观察到的SST昼夜循环从个别船舶参考漂流浮标在风和太阳辐射的类似条件下进行比较。与现有的估计相比，我们发现了大量的发动机室进气道（ERI）的报告后，第二次世界大战和1960年至1980年期间。与以前的估计相比，推断的混合观测的差异导致从1980年开始的偏差调整SST异常的系统性暖移，同时减少了集合传播。桶和ERI SST异常在北方半球在1955年至1995年期间的平均场差异的变化可能是高达0.5摄氏度，并没有很好地再现当前的偏差调整models.Plain语言摘要海表温度（SST）是气候变化的一个重要指标，但它的不确定性影响我们的信心，在估计全球表面温度变化。SST不确定性（或偏差）的一个主要系统成分是由船上SST观测实践的变化引起的。从历史上看，SST测量要么使用水桶收集水样，要么记录用于冷却船舶发动机（发动机室进气口（ERI））的泵送海水的温度。由于SST观测偏差因测量方法而异，量化SST偏差的经验模型必须分别应用于桶和ERI SST。由于缺乏关于所采用的测量方法的可靠资料，这一办法受到阻碍。我们提出了一个独立的评估SST测量实践得出比较昼夜SST变化从个别船舶与漂流浮标在类似条件下计算。新推断的混合观测导致系统的偏置调整SST距平从1980年相比，以前的估计温暖的转变，同时减少了这些估计的不确定性。桶ERI平均SST异常差异的变化并没有完全重现目前的偏差调整模式。这些结果对估计SST趋势和变率变化的不确定性具有重要意义。
Lack of reliable observational metadata represents a key barrier to understanding sea surface temperature (SST) measurement biases, a large contributor to uncertainty in the global surface record. We present a method to identify SST measurement practice by comparing the observed SST diurnal cycle from individual ships with a reference from drifting buoys under similar conditions of wind and solar radiation. Compared to existing estimates, we found a larger number of engine room-intake (ERI) reports post-World War II and in the period 1960-1980. Differences in the inferred mixture of observations lead to a systematic warmer shift of the bias adjusted SST anomalies from 1980 compared to previous estimates, while reducing the ensemble spread. Changes in mean field differences between bucket and ERI SST anomalies in the Northern Hemisphere over the period 1955-1995 could be as large as 0.5 degrees C and are not well reproduced by current bias adjustment models.Plain Language Summary The sea surface temperature (SST) is an important indicator of climate change but its uncertainty affects our confidence in estimates of global surface temperature change. A main systematic component of SST uncertainty (or bias) is caused by changes in SST observational practice onboard ships. Historically, SST measurements have been made either using buckets to collect water samples or recording the temperature of pumped seawater used to cool the ship engines (engine room-intake (ERI)). Because SST observational biases vary by measurement method, empirical models to quantify SST biases must be applied separately to bucket and ERI SSTs. This approach is hampered by the lack of reliable information on the adopted measurement method. We present an independent assessment of SST measurement practice derived comparing diurnal SST variations from individual ships with those computed from drifting buoys under similar conditions. The newly inferred mixture of observations leads to a systematic warmer shift of the bias-adjusted SST anomalies from 1980 compared to previous estimates, while reducing the uncertainty in these estimates. Changes in bucket-ERI mean SST anomaly differences are not fully reproduced by current bias adjustment models. These results have important implications for estimates of uncertainty in SST trends and variability changes.