Extremes become routine in an emerging new Arctic
Extremes become routine in an emerging new Arctic
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DOI：
10.1038/s41558-020-0892-z
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发表时间：
2020-09-14
影响因子：
30.7
通讯作者：
Holland, Marika M.
中科院分区：
文献类型：
--
作者：
Landrum, Laura;Holland, Marika M.
北极正在迅速变暖，海冰、海洋和陆地区域正在发生巨大变化。由于缺乏长期的科学观测，很难评估北极的变化在统计上是否代表了“新北极”气候。在这里，我们使用五个耦合模型比对项目 5 类地球系统模型大型集合来展示北极如何从主要冰冻状态过渡，并量化海冰、气温和降水阶段（雨与雪）中新兴北极气候的性质和时间。我们的结果表明北极气候已经在海冰中出现。气温将在 21 世纪早期到中期出现在代表性浓度路径 8.5 情景下，随后出现降水相变化。尽管平均状态和强制响应存在差异，但这些模型在北极海冰内部变化、地表温度和降水阶段变化等人为强制出现方面表现出惊人的相似性。较短的观测记录使得很难判断最近北极变暖的程度是史无前例的。一个多模型大型集合估计，就海冰范围而言，新的北极气候已经出现。随着北极从主要冰冻状态转变，气温和降水会在几十年内发生变化。
The Arctic is rapidly warming and experiencing tremendous changes in sea ice, ocean and terrestrial regions. Lack of long-term scientific observations makes it difficult to assess whether Arctic changes statistically represent a 'new Arctic' climate. Here we use five Coupled Model Intercomparison Project 5 class Earth system model large ensembles to show how the Arctic is transitioning from a dominantly frozen state and to quantify the nature and timing of an emerging new Arctic climate in sea ice, air temperatures and precipitation phase (rain versus snow). Our results suggest that Arctic climate has already emerged in sea ice. Air temperatures will emerge under the representative concentration pathway 8.5 scenario in the early- to mid-twenty-first century, followed by precipitation-phase changes. Despite differences in mean state and forced response, these models show striking similarities in their anthropogenically forced emergence from internal variability in Arctic sea ice, surface temperatures and precipitation-phase changes.The short observational record makes it difficult to gauge how unprecedented recent Arctic warming is. A multi-model large ensemble estimates a new Arctic climate has emerged for sea-ice extent. As the Arctic shifts from a primarily frozen state, temperature and precipitation follow within decades.