Domingues Catia M, Church John A, White Neil J, Gleckler Peter J, Wijffels Susan E, Barker Paul M, Dunn Jeff R
Centre for Australian Weather and Climate Research, CSIRO Marine and Atmospheric Research, GPO Box 1538, Hobart, Tasmania 7001, Australia.
Nature. 2008 Jun 19;453(7198):1090-3. doi: 10.1038/nature07080.
Changes in the climate system's energy budget are predominantly revealed in ocean temperatures and the associated thermal expansion contribution to sea-level rise. Climate models, however, do not reproduce the large decadal variability in globally averaged ocean heat content inferred from the sparse observational database, even when volcanic and other variable climate forcings are included. The sum of the observed contributions has also not adequately explained the overall multi-decadal rise. Here we report improved estimates of near-global ocean heat content and thermal expansion for the upper 300 m and 700 m of the ocean for 1950-2003, using statistical techniques that allow for sparse data coverage and applying recent corrections to reduce systematic biases in the most common ocean temperature observations. Our ocean warming and thermal expansion trends for 1961-2003 are about 50 per cent larger than earlier estimates but about 40 per cent smaller for 1993-2003, which is consistent with the recognition that previously estimated rates for the 1990s had a positive bias as a result of instrumental errors. On average, the decadal variability of the climate models with volcanic forcing now agrees approximately with the observations, but the modelled multi-decadal trends are smaller than observed. We add our observational estimate of upper-ocean thermal expansion to other contributions to sea-level rise and find that the sum of contributions from 1961 to 2003 is about 1.5 +/- 0.4 mm yr(-1), in good agreement with our updated estimate of near-global mean sea-level rise (using techniques established in earlier studies) of 1.6 +/- 0.2 mm yr(-1).
气候系统能量平衡的变化主要体现在海洋温度以及与之相关的热膨胀对海平面上升的贡献上。然而，即便将火山活动及其他可变气候强迫因素考虑在内，气候模型仍无法再现从稀疏观测数据库推断出的全球平均海洋热含量的大幅年代际变化。观测到的各项贡献之和也未能充分解释海平面的总体年代际上升情况。在此，我们报告了对1950 - 2003年海洋上层300米和700米深度近全球海洋热含量及热膨胀的改进估算结果，采用了能适应稀疏数据覆盖的统计技术，并应用了最新校正方法以减少最常见海洋温度观测中的系统偏差。我们得出的1961 - 2003年海洋变暖及热膨胀趋势比早期估算值大约高50%，但在1993 - 2003年期间则比早期估算值小约40%，这与人们认识到的情况相符，即由于仪器误差，先前估算的20世纪90年代速率存在正偏差。平均而言，包含火山强迫因素的气候模型的年代际变化现在大致与观测结果相符，但模拟的年代际趋势小于观测值。我们将海洋上层热膨胀的观测估算值与海平面上升的其他贡献相加，发现1961年至2003年各项贡献之和约为1.5±0.4毫米/年，这与我们更新后的近全球平均海平面上升估算值（使用早期研究中确立的技术）1.6±0.2毫米/年高度吻合。
