Key indicators of Arctic climate change: 1971-2017
Key indicators of Arctic climate change: 1971-2017
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DOI：
10.1088/1748-9326/aafc1b
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发表时间：
2019-04-01
影响因子：
6.7
通讯作者：
Olsen, Morten Skovgard
中科院分区：
文献类型：
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作者：
Box, Jason E.;Colgan, William T.;Olsen, Morten Skovgard
北极气候变化的主要观测指标，大部分跨越47年（1971-2017年），表明北极系统的九个关键要素发生了根本变化。我们发现，随着气温的升高，水文循环也在加剧，这可以从湿度、降水、河流流量、冰川平衡线高度和陆冰损耗的增加中看出。海冰厚度（和范围）、春雪覆盖范围和持续时间继续呈下降趋势，而近地表永久冻土继续变暖。若干气候指标显示出与气温或降水的显著统计相关性，强化了气温和降水增加是北极系统各组成部分发生重大变化的驱动因素这一概念。为了超越对北极物理气候变化的介绍，我们发现了气温与生物物理指标（如苔原生物量）之间的对应关系，并确定了在整个营养水平上具有级联效应的许多生物物理中断。这包括：向北极近海岸地区输送更多的有机物和营养物；缩短开花和授粉植物物种周期；植物开花与传粉者的时间不匹配；增加植物对昆虫干扰的脆弱性；灌木生物量增加；野火燃烧增加；生长季CO2吸收增加，平季和冬季CO2排放抵消增加；碳循环增加，受当地水文和永久冻土融化的调节；陆地和水生生态系统之间的转换；以及动物分布和人口结构的变化。北极的生物物理系统现在显然正在远离20世纪的状态，进入一个前所未有的状态，其影响不仅在北极内部，而且在北极之外。
Key observational indicators of climate change in the Arctic, most spanning a 47 year period (1971-2017) demonstrate fundamental changes among nine key elements of the Arctic system. We find that, coherent with increasing air temperature, there is an intensification of the hydrological cycle, evident from increases in humidity, precipitation, river discharge, glacier equilibrium line altitude and land ice wastage. Downward trends continue in sea ice thickness (and extent) and spring snow cover extent and duration, while near-surface permafrost continues to warm. Several of the climate indicators exhibit a significant statistical correlation with air temperature or precipitation, reinforcing the notion that increasing air temperatures and precipitation are drivers of major changes in various components of the Arctic system. To progress beyond a presentation of the Arctic physical climate changes, we find a correspondence between air temperature and biophysical indicators such as tundra biomass and identify numerous biophysical disruptions with cascading effects throughout the trophic levels. These include: increased delivery of organic matter and nutrients to Arctic near-coastal zones; condensed flowering and pollination plant species periods; timing mismatch between plant flowering and pollinators; increased plant vulnerability to insect disturbance; increased shrub biomass; increased ignition of wildfires; increased growing season CO2 uptake, with counterbalancing increases in shoulder season and winter CO2 emissions; increased carbon cycling, regulated by local hydrology and permafrost thaw; conversion between terrestrial and aquatic ecosystems; and shifting animal distribution and demographics. The Arctic biophysical system is now clearly trending away from its 20th Century state and into an unprecedented state, with implications not only within but beyond the Arctic.