Drivers and predictability of forest fire activity across the circumboreal zone of Northern Hemisphere (PREFIRE)

在月度、季节性和高于年度的时间尺度上预测森林火灾活动的能力对于减轻其影响至关重要，包括火灾驱动的生态系统动态和社会经济服务。火灾是北方森林生态系统动态的主要驱动因子，直接影响全球碳平衡和大气中微量气体（包括二氧化碳）的浓度。海洋-大气系统的弹性为提前探测即将到来的火灾季节强度提供了潜力。涉及世界海洋能量平衡和相关大气压力模式的大尺度异常已被反复证明影响干旱条件，指出湿度和能量输送的大尺度变化是区域火灾活动的重要驱动因素。早期的研究表明，海面温度（SST）的变化与相关的压力模式之间存在很强的联系，从而迫使陆地降水发生变化，进而影响区域火灾状况。可以合理地预期，海洋和大气之间的类似遥相关，控制着火情，扩展到整个环周区域。这种遥相关的一个可能来源是北极气候（如海冰状况）、厄尔尼诺-南方涛动（ENSO）和大西洋多年代际涛动（AMO）之间的相互作用。特别是，这种生物群系靠近寒冷和干燥的北极气团，使北方森林对持续的气候变化敏感，增加了长期极端天气事件的可能性，包括春季和夏季干旱。森林火灾活动增加背后的极端气候也可能是大气特征的全球特征的产物，例如行星波的放大。PREFIRE旨在：***(1)通过对现代和历史火灾活动和气候-海洋变率的多种代用物的分析，确定控制北方火灾活动的气候驱动因素及其在月、季和年时间尺度上的可预测性；***(2)提供未来火灾活动的年代际和世纪尺度预测，并将其转化为对生态系统服务（特别是森林生产力和碳储存能力）的影响。我认为，使用大量的树木年代学重建有很大的潜力来提高极端天气的可预测性，比如区域性火灾活动增加的时期。我建议，他们对独立获得的气候变率和植被覆盖代用物的分析，应该有助于更好地了解森林火灾的现代气候驱动因素，以及在多个时间尺度上火灾活动的可预测性。

The ability to predict forest fire activity at the monthly, seasonal, and above-annual time scales is critical to mitigate its impacts, including the fire-driven dynamics of the ecosystem and socio-economic services. Fire is the primary driving factor of ecosystem dynamics in the boreal forest, directly affecting global carbon balance and atmospheric concentrations of the trace gases, including carbon dioxide. The resilience of the ocean-atmosphere system provides the potential for the advanced detection of the upcoming fire season intensity. Large scale anomalies involving the energy balance of world oceans and the associated atmospheric pressure patterns have been repeatedly shown to affect drought conditions, pointing to the large-scale changes in humidity and energy transport as important drivers of regional fire activity. Earlier studies showed strong links between changes in sea surface temperatures (SST) and associated pressure patterns, forcing changes in land precipitation and, subsequently, regional fire regimes. It is reasonable to expect that similar teleconnections between ocean and atmosphere, controlling fire regimes, extend over the entire circumboreal region. A likely source of such teleconnections is interactions between the Arctic climate (such as the sea-ice conditions), El Nino Southern Oscillations (ENSO), and Atlantic Multi-decadal Oscillations (AMO). In particular, the proximity of this biome to cold and dry Arctic air masses makes the boreal forests sensitive to the ongoing climate change, increasing the probability of long-lasting extreme weather events, including spring and summer droughts. It is also possible that climate extremes behind the increase in forest fire activity may be a product of global features of atmospheric features, such as amplification of planetary waves. PREFIRE seeks: ***(1) to identify climatic drivers controlling boreal fire activity and its predictability at the monthly, seasonal and annual timescales by relying on analyses of multiple proxies of modern and historic fire activity and climate-ocean variability, and ***(2) to provide decadal and century-scale predictions of future fire activity and to translate them into impacts on ecosystem services (in particular forest productivity and C storage capacity). ***I argue that there is a strong potential in using a large body of dendrochronological reconstructions to improve the predictability of weather extremes, such as periods of regionally increased fire activity. I propose that their analyses with independently obtained proxies of climate variability and vegetation cover should contribute towards better knowledge of modern climate drivers of forest fires and the predictability of fire activity at multiple temporal scales.