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气候变化引发的野火导致浮游植物大量繁殖
2021-09-18 15:10

美国杜克大学尼古拉斯环境学院Nicolas Cassar和澳大利亚联邦科学与工业研究组织Richard Matear研究组合作取得最新进展。他们发现2019-2020 年澳大利亚野火引发广泛的浮游植物大量繁殖。2021年9月15日,国际知名学术期刊《自然》发表了这一成果。

他们使用卫星和自主生物地球化学 Argo 浮标数据来评估 2019-2020 年澳大利亚野火气溶胶沉积对浮游植物生产力的影响。他们发现从 2019 年 12 月到 2020 年 3 月在澳大利亚下风的南大洋异常广泛的浮游植物大量繁殖。源自澳大利亚野火的气溶胶样本含有高的铁含量,大气轨迹表明这些气溶胶很可能被输送到水华地区,这表明水华是由南大洋铁限制水域施肥造成的。

气候模型预测许多地区会出现更频繁和更严重的野火。更好地了解野火、热解气溶胶、养分循环和海洋光合作用之间的联系,可以提高人们对大气 CO2 和全球气候系统的当代和冰期-间冰期循环的理解。

据介绍,干旱和气候变化导致的变暖正在导致更频繁和更强烈的野火,可以说是导致 2019-2020 年澳大利亚严重野火的原因。火灾的环境和生态影响包括栖息地的丧失和大量大气气溶胶的排放。野火产生的气溶胶排放可导致常量营养素和生物必需微量金属(分别如氮和铁)的大气运输。有人提出,野火气溶胶的海洋沉积可以缓解营养限制,从而提高海洋生产力,但缺乏证据。

附:英文原文

Title: Widespread phytoplankton blooms triggered by 2019–2020 Australian wildfires

Author: Tang, Weiyi, Llort, Joan, Weis, Jakob, Perron, Morgane M. G., Basart, Sara, Li, Zuchuan, Sathyendranath, Shubha, Jackson, Thomas, Sanz Rodriguez, Estrella, Proemse, Bernadette C., Bowie, Andrew R., Schallenberg, Christina, Strutton, Peter G., Matear, Richard, Cassar, Nicolas

Issue&Volume: 2021-09-15

Abstract: Droughts and climate-change-driven warming are leading to more frequent and intense wildfires1,2,3, arguably contributing to the severe 2019–2020 Australian wildfires4. The environmental and ecological impacts of the fires include loss of habitats and the emission of substantial amounts of atmospheric aerosols5,6,7. Aerosol emissions from wildfires can lead to the atmospheric transport of macronutrients and bio-essential trace metals such as nitrogen and iron, respectively8,9,10. It has been suggested that the oceanic deposition of wildfire aerosols can relieve nutrient limitations and, consequently, enhance marine productivity11,12, but direct observations are lacking. Here we use satellite and autonomous biogeochemical Argo float data to evaluate the effect of 2019–2020 Australian wildfire aerosol deposition on phytoplankton productivity. We find anomalously widespread phytoplankton blooms from December 2019 to March 2020 in the Southern Ocean downwind of Australia. Aerosol samples originating from the Australian wildfires contained a high iron content and atmospheric trajectories show that these aerosols were likely to be transported to the bloom regions, suggesting that the blooms resulted from the fertilization of the iron-limited waters of the Southern Ocean. Climate models project more frequent and severe wildfires in many regions1,2,3. A greater appreciation of the links between wildfires, pyrogenic aerosols13, nutrient cycling and marine photosynthesis could improve our understanding of the contemporary and glacial–interglacial cycling of atmospheric CO2 and the global climate system.

DOI: 10.1038/s41586-021-03805-8

Source: https://www.nature.com/articles/s41586-021-03805-8

Nature:《自然》,创刊于1869年。隶属于施普林格·自然出版集团,最新IF:69.504
官方网址:http://www.nature.com/
投稿链接:http://www.nature.com/authors/submit_manuscript.html


本期文章:《自然》:Online/在线发表

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