Footprint of greenhouse forcing in daily temperature variability
Footprint of greenhouse forcing in daily temperature variability
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DOI：
10.1073/pnas.2103294118
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发表时间：
2021-08-10
影响因子：
11.1
通讯作者：
Levermann, Anders
中科院分区：
文献类型：
--
作者：
Kotz, Maximilian;Wenz, Leonie;Levermann, Anders
在持续的人为全球变暖下，平均气候条件的变化将对自然和社会系统产生深远影响。温度的高频变化带来了额外的压力，然而温室强迫对其的影响还没有在观测数据中得到充分的评估或确认。在这里，我们表明，随着温室气体浓度的增加，日地表温度的月内变率变化具有明显的全球模式。在对历史观测和最新预测的重新分析中，随着温室效应的加强，变化在中低纬度增加，在北部中高纬度减少。利用最近开发的信号音调最大化模式滤波技术，从内部气候变化中识别出这些纬向极化的日变化。对耦合模式相互比较项目第六阶段的多模式集合的分析表明，这些变化可归因于温室强迫的增强。到本世纪末，在商业正常排放的情况下，低纬度地区的日温度变率将继续增加高达100%，北部高纬度地区的日温度变率将减少40%。其他情景表明，这些变化将受到温室气体减排的限制。此外，全球日变率的变化与气候模型中的变暖表现出很强的协变性，这表明平衡的气候敏感性也将在决定未来变率变化的程度方面发挥作用。如果不采取缓解和保护措施，高频气候系统对温室压力增加的这种全球反应可能会对社会、经济和生态系统产生强烈和不平等的影响。
Changes in mean climatic conditions will affect natural and societal systems profoundly under continued anthropogenic global warming. Changes in the high-frequency variability of temperature exert additional pressures, yet the effect of greenhouse forcing thereon has not been fully assessed or identified in observational data. Here, we show that the intramonthly variability of daily surface temperature changes with distinct global patterns as greenhouse gas concentrations rise. In both reanalyses of historical observations and state-of-the-art projections, variability increases at low to mid latitudes and decreases at northern mid to high latitudes with enhanced greenhouse forcing. These latitudinally polarized daily variability changes are identified from internal climate variability using a recently developed signal-tonoise-maximizing pattern-filtering technique. Analysis of a multimodel ensemble from the Coupled Model Intercomparison Project Phase 6 shows that these changes are attributable to enhanced greenhouse forcing. By the end of the century under a businessas-usual emissions scenario, daily temperature variability would continue to increase by up to a further 100% at low latitudes and decrease by 40% at northern high latitudes. Alternative scenarios demonstrate that these changes would be limited by mitigation of greenhouse gases. Moreover, global changes in daily variability exhibit strong covariation with warming across climate models, suggesting that the equilibrium climate sensitivity will also play a role in determining the extent of future variability changes. This global response of the high-frequency climate system to enhanced greenhouse forcing is likely to have strong and unequal effects on societies, economies, and ecosystems if mitigation and protection measures are not taken.