论文标题
弹性功能变更点检测气候影响的局部源
Elastic Functional Changepoint Detection of Climate Impacts from Localized Sources
论文作者
论文摘要
检测功能数据中的变更点已成为一个重要的问题，因为监测气候现象的兴趣增加了，而数据在本质上是有效的。观察到的数据通常包含振幅（$ y $轴）和阶段（$ x $轴）变异性。如果未正确考虑，则可能未发现真实的更改点，并且估计的基本平均更改功能将是不正确的。在本文中，开发了一种弹性功能更改方法，该方法适当说明了这些类型的可变性。该方法可以检测文献中当前方法没有的幅度和相变点，因为它们仅关注振幅更改点。可以直接使用功能轻松实现此方法，也可以通过功能主组件分析来计算以减轻计算负担。我们将该方法及其非弹性竞争对手应用于模拟数据和观察数据，以显示其在具有幅度和相变点的相变的数据方面的效率。我们使用该方法来评估1991年6月菲律宾\ pinatubo山的喷发引起的平流层温度的潜在变化。使用流行病更改点模型，我们发现了平流层温度升高的证据，其中包含\ pinatubo Mt. \ pinatubo的后果，最终检测到的变化点最为可预期。
Detecting changepoints in functional data has become an important problem as interest in monitoring of climate phenomenon has increased, where the data is functional in nature. The observed data often contains both amplitude ($y$-axis) and phase ($x$-axis) variability. If not accounted for properly, true changepoints may be undetected, and the estimated underlying mean change functions will be incorrect. In this paper, an elastic functional changepoint method is developed which properly accounts for these types of variability. The method can detect amplitude and phase changepoints which current methods in the literature do not, as they focus solely on the amplitude changepoint. This method can easily be implemented using the functions directly or can be computed via functional principal component analysis to ease the computational burden. We apply the method and its non-elastic competitors to both simulated data and observed data to show its efficiency in handling data with phase variation with both amplitude and phase changepoints. We use the method to evaluate potential changes in stratospheric temperature due to the eruption of Mt.\ Pinatubo in the Philippines in June 1991. Using an epidemic changepoint model, we find evidence of a increase in stratospheric temperature during a period that contains the immediate aftermath of Mt.\ Pinatubo, with most detected changepoints occurring in the tropics as expected.
