Future Changes of Snow in Alaska and the Arctic under Stabilized Global Warming Scenarios
Future Changes of Snow in Alaska and the Arctic under Stabilized Global Warming Scenarios
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DOI：
10.3390/atmos13040541
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发表时间：
2022-04-01
期刊：
影响因子：
2.9
通讯作者：
Walsh, John E.
中科院分区：
文献类型：
--
作者：
Bigalke, Siiri;Walsh, John E.
全球变暖在北极的表现包括气温上升幅度扩大和降水量普遍增加。虽然地形使阿拉斯加等地区的这些变化模式复杂化，但观测数据已经明显显示出变暖和降水量普遍增加的现象。积雪的变化由于变暖和降水增加的相反影响而变得复杂。在这项研究中，分析了社区大气模型第5版模拟的高分辨率（0.25度）输出，以了解在1.5摄氏度、2.0摄氏度和3.0摄氏度的稳定全球变暖情景下雪的变化。未来降雪量变化的特点是阿拉斯加的南北梯度和欧亚大陆的东西梯度。预计阿拉斯加北方、加拿大北方和西伯利亚的降雪量将增加，而阿拉斯加南部和欧洲等温和地区在气候变暖的情况下降雪量将减少。总的来说，结果表明，北极55度以北的大部分土地面积将减少降雪。全球变暖的近似阈值为泛北极陆地面积50%以上的温度统计上显著增加1.5摄氏度。相应的降水阈值约为2.0摄氏度。阿拉斯加高海拔积雪损失的全球变暖阈值约为2.0摄氏度。研究结果表明，将全球变暖限制在巴黎协定的目标范围内是防止阿拉斯加和北极冬季气候发生重大变化的必要条件。
Manifestations of global warming in the Arctic include amplifications of temperature increases and a general increase in precipitation. Although topography complicates the pattern of these changes in regions such as Alaska, the amplified warming and general increase in precipitation are already apparent in observational data. Changes in snow cover are complicated by the opposing effects of warming and increased precipitation. In this study, high-resolution (0.25 degrees) outputs from simulations by the Community Atmosphere Model, version 5, were analyzed for changes in snow under stabilized global warming scenarios of 1.5 degrees C, 2.0 degrees C and 3.0 degrees C. Future changes in snowfall are characterized by a north-south gradient over Alaska and an east-west gradient over Eurasia. Increased snowfall is projected for northern Alaska, northern Canada and Siberia, while milder regions such as southern Alaska and Europe receive less snow in a warmer climate. Overall, the results indicate that the majority of the land area poleward of 55 degrees N will experience a reduction in snow. The approximate threshold of global warming for a statistically significant increase in temperature over 50% of the pan-Arctic land area is 1.5 degrees C. The corresponding threshold for precipitation is approximately 2.0 degrees C. The global warming threshold for the loss of high-elevation snow in Alaska is approximately 2.0 degrees C. The results imply that limiting global warming to the Paris Agreement target is necessary to prevent significant changes in winter climates in Alaska and the Arctic.