近日，英国剑桥大学Strawson, Ivo和
在这项研究中，研究人员重建了1821年至1995年间南极冰芯CO的连续记录，以与直接大气观测重叠。记录显示，南半球的CO负荷([CO])比工业前的混合比例ca.35ppb增加了50%，到1995CE为ca.53ppb，比最先进的化学-气候模型所允许的可变性更大，这表明历史上的CO动力学没有得到充分的解释。研究使用6对流层箱模型，结果显示，南半球生物质燃烧排放减少40%至50%，与20世纪初早期人类活动引起的土地利用变化速率空前一致，该原因也被确定为这种不匹配的一个强有力的候选因素。
据介绍，生物质燃烧在气候作用力和大气化学中起着重要作用。然而，在过去的两个世纪里，火灾活动的驱动因素引起了激烈的争论，并且由于对热带雨林前火灾制度的规模和趋势的限制不足而更加激烈。作为生物质燃烧的有力示踪剂，古大气一氧化碳(CO)的重建可以为研究工业前向工业过渡期间的，火灾活动演化提供有价值的信息。然而，现有CO记录之间的重大分歧目前也允许对立的火灾历史。
附：英文原文
Title: Historical Southern Hemisphere biomass burning variability inferred from ice core carbon monoxide records
Author: Strawson, Ivo, Fan, Xavier, Bauska, Thomas K., Muschitiello, Francesco, Vladimirova, Diana O., Tetzner, Dieter R., Humby, Jack, Thomas, Elizabeth R., Liu, Pengfei, Zhang, Bingqing, Grilli, Roberto, Rhodes, Rachael H.
Issue&Volume: 2024-8-5
Abstract: Biomass burning plays an important role in climate-forcing and atmospheric chemistry. The drivers of fire activity over the past two centuries, however, are hotly debated and fueled by poor constraints on the magnitude and trends of preindustrial fire regimes. As a powerful tracer of biomass burning, reconstructions of paleoatmospheric carbon monoxide (CO) can provide valuable information on the evolution of fire activity across the preindustrial to industrial transition. Here too, however, significant disagreements between existing CO records currently allow for opposing fire histories. In this study, we reconstruct a continuous record of Antarctic ice core CO between 1821 and 1995 CE to overlap with direct atmospheric observations. Our record indicates that the Southern Hemisphere CO burden ([CO]) increased by 50% from a preindustrial mixing ratio of ca. 35 ppb to ca. 53 ppb by 1995 CE with more variability than allowed for by state-of-the-art chemistry-climate models, suggesting that historic CO dynamics have been not fully accounted for. Using a 6-troposphere box model, a 40 to 50% decrease in Southern Hemisphere biomass-burning emissions, coincident with unprecedented rates of early 20th century anthropogenic land-use change, is identified as a strong candidate for this mismatch.
DOI: 10.1073/pnas.2402868121
Source: https://www.pnas.org/doi/abs/10.1073/pnas.2402868121