Volcanic cooling signal in tree ring temperature records for the past millennium
Volcanic cooling signal in tree ring temperature records for the past millennium
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DOI：
10.1002/jgrd.50692
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发表时间：
2013-08-27
影响因子：
4.4
通讯作者：
Anchukaitis, Kevin J.
中科院分区：
文献类型：
--
作者：
D'Arrigo, Rosanne;Wilson, Rob;Anchukaitis, Kevin J.
树木年轮是了解火山爆发的时间和环境后果的一个重要代用指标，因为它们是以年度分辨率精确测定日期的，特别是在世界上的树木线地区，对气候上重要的火山事件可能造成的极端寒冷敏感。火山信号已被检测到的年轮宽度和霜冻损坏的戒指的存在下，但往往是最清楚和定量表示内最大晚材密度系列。环的宽度和密度重建提供了定量信息，推断当地的半球尺度上的地球气候系统的变异性和敏感性。经过一个世纪的树木年代学研究，没有证据表明火山或其他不利事件导致纬度树线附近的严寒条件，以至于在火山年，给定地点的所有树木的年轮都可能丢失（全林年轮缺失），导致年表的日期错误。相反，根据实际的树木年轮观测和建模分析，即使在不利的寒冷条件下，在任何特定地点，至少有一些树木的年轮的精确测年和发展都有明确的迹象。大规模温度重建中火山冷却的无声证据至少部分基于环宽度，反映了几个与任何错定年代完全无关的因素。这些因素包括这些记录的生物持久性，以及气候系统对火山事件的不同空间响应模式，因此区域冷却，特别是环宽度而不是密度，可以在大规模重建平均值中被掩盖。
Tree rings are an important proxy for understanding the timing and environmental consequences of volcanic eruptions as they are precisely dated at annual resolution and, particularly in tree line regions of the world, sensitive to cold extremes that can result from climatically significant volcanic episodes. Volcanic signals have been detected in ring widths and by the presence of frost-damaged rings, yet are often most clearly and quantitatively represented within maximum latewood density series. Ring width and density reconstructions provide quantitative information for inferring the variability and sensitivity of the Earth's climate system on local to hemispheric scales. After a century of dendrochronological science, there is no evidence, as recently theorized, that volcanic or other adverse events cause such severely cold conditions near latitudinal tree line that rings might be missing in all trees at a given site in a volcanic year (stand-wide missing rings), resulting in misdating of the chronology. Rather, there is a clear indication of precise dating and development of rings in at least some trees at any given site, even under adverse cold conditions, based on both actual tree ring observations and modeling analyses. The muted evidence for volcanic cooling in large-scale temperature reconstructions based at least partly on ring widths reflects several factors that are completely unrelated to any misdating. These include biological persistence of such records, as well as varying spatial patterns of response of the climate system to volcanic events, such that regional cooling, particularly for ring widths rather than density, can be masked in the large-scale reconstruction average.