Measurements and models of the temperature change of water samples in sea-surface temperature buckets
Measurements and models of the temperature change of water samples in sea-surface temperature buckets
复制标题
海面温度桶中水样温度变化的测量和模型
DOI：
10.1002/qj.3078
复制
发表时间：
2017
影响因子：
8.9
通讯作者：
Carella G
中科院分区：
文献类型：
--
作者：
Carella G
使用桶进行的历史海表温度（SST）测量的偏差调整的不确定性被认为对全球表面温度趋势的不确定性贡献最大。将木桶和帆布桶中水样温度变化的测量结果与广泛使用的海温网格分析中用于估计偏差调整的模型的预测结果进行比较。结果表明，该模型能够较好地预测水的温度随时间变化对热强迫和桶形特征的依赖关系：体积和几何形状；结构和材料。模型和观测结果都表明，在历史水桶测量中，驱动温度偏差的最重要的环境参数是水和湿球温度之间的差异。然而，模型推导中固有的假设可能会影响其适用性。我们观察到，水样需要大力搅拌才能与模型的结果一致，该模型假设了良好的混合条件。模型结果与1951年在风洞中进行的测量结果不一致。该模型假设非湍流入射流，因此预测了与气流速度的近似平方根依赖关系。在大范围的气流中进行的风洞测量显示出更强的依赖性。湍流存在时，传热随湍流强度的增大而增大；对于在船上进行的测量，入射气流很可能是湍流的，而湍流的强度总是未知的。综上所述，湍流的影响和混合良好的水样假设造成的不确定性预计将是很大的，并且可能是直接应用这些模式来调整历史海温观测值的限制因素。
Uncertainty in the bias adjustments applied to historical sea‐surface temperature (SST) measurements made using buckets are thought to make the largest contribution to uncertainty in global surface temperature trends. Measurements of the change in temperature of water samples in wooden and canvas buckets are compared with the predictions of models that have been used to estimate bias adjustments applied in widely used gridded analyses of SST. The results show that the models are broadly able to predict the dependence of the temperature change of the water over time on the thermal forcing and the bucket characteristics: volume and geometry; structure and material. Both the models and the observations indicate that the most important environmental parameter driving temperature biases in historical bucket measurements is the difference between the water and wet‐bulb temperatures. However, assumptions inherent in the derivation of the models are likely to affect their applicability. We observed that the water sample needed to be vigorously stirred to agree with results from the model, which assumes well‐mixed conditions. There were inconsistencies between the model results and previous measurements made in a wind tunnel in 1951. The model assumes non‐turbulent incident flow and consequently predicts an approximately square‐root dependence on airflow speed. The wind tunnel measurements, taken over a wide range of airflows, showed a much stronger dependence. In the presence of turbulence the heat transfer will increase with the turbulent intensity; for measurements made on ships the incident airflow is likely to be turbulent and the intensity of the turbulence is always unknown. Taken together, uncertainties due to the effects of turbulence and the assumption of well‐mixed water samples are expected to be substantial and may represent the limiting factor for the direct application of these models to adjust historical SST observations.