Long-term persistence enhances uncertainty about anthropogenic warming of Antarctica
Long-term persistence enhances uncertainty about anthropogenic warming of Antarctica
复制标题
DOI：
10.1007/s00382-015-2582-5
复制
发表时间：
2016-01-01
期刊：
影响因子：
4.6
通讯作者：
Schellnhuber, Hans Joachim
中科院分区：
文献类型：
--
作者：
Ludescher, Josef;Bunde, Armin;Schellnhuber, Hans Joachim
以前对观测到的南极温度趋势的强度和不确定性的估计假设自然年温度波动可以用一阶自回归过程表示[AR（1）]。在这里，我们发现这个假设是不充分的。我们认为，在南极洲最长的观测温度记录，并表明，他们的变化是更好地代表了一个长期的持续过程，有一个大的和持久的自然偏移的平均倾向。因此，最近（推测是人为的）南极变暖趋势的统计意义低于迄今为止的报告，而其幅度的不确定性增加。事实上，除了一个（法拉第/Vernadsky）之外，所有的记录都没有显示出明显的趋势。当考虑适当的当地温度序列平均值以提高信噪比时，我们发现东南极和南极半岛的变暖趋势仍然不明显。然而，在南极洲西部，这一趋势的重要性超过97.4%，其幅度在每十年0.08至0.96摄氏度之间。我们认为，持续的温度波动不仅对区域变暖的不确定性有更大的影响比以前认为的，但也可能提供一个潜在的机制，了解短暂的减弱（“中断”）的区域和全球温度趋势。
Previous estimates of the strength and the uncertainty of the observed Antarctic temperature trends assumed that the natural annual temperature fluctuations can be represented by an auto-regressive process of first order [AR(1)]. Here we find that this hypothesis is inadequate. We consider the longest observational temperature records in Antarctica and show that their variability is better represented by a long-term persistent process that has a propensity of large and enduring natural excursions from the mean. As a consequence, the statistical significance of the recent (presumably anthropogenic) Antarctic warming trend is lower than hitherto reported, while the uncertainty about its magnitude is enhanced. Indeed, all records except for one (Faraday/Vernadsky) fail to show a significant trend. When increasing the signal-to-noise ratio by considering appropriate averages of the local temperature series, we find that the warming trend is still not significant in East Antarctica and the Antarctic Peninsula. In West Antarctica, however, the significance of the trend is above 97.4%, and its magnitude is between 0.08 and 0.96 degrees C per decade. We argue that the persistent temperature fluctuations not only have a larger impact on regional warming uncertainties than previously thought but also may provide a potential mechanism for understanding the transient weakening ("hiatus") of the regional and global temperature trends.