High northern latitude forest fires and vegetation emissions over the last millennium inferred from the chemistry of a central Greenland ice core
High northern latitude forest fires and vegetation emissions over the last millennium inferred from the chemistry of a central Greenland ice core
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根据格陵兰岛中部冰芯的化学成分推断出过去千年的高北纬度森林火灾和植被排放
DOI：
10.1029/97jd03748
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发表时间：
1998
影响因子：
--
通讯作者：
M. Legrand
中科院分区：
文献类型：
--
作者：
J. Savarino;M. Legrand
我们分析了从公元1193年至今在萨米特（格陵兰中部）积累的固体沉淀中捕获的杂质的可溶性部分。73个冰层显示铵和甲酸盐浓度升高，这是由高纬度生物质燃烧碎片到达格陵兰造成的。虽然在这些冰层中通常观察到接近摩尔比的铵和甲酸盐的混合物，但在少数情况下发现甲酸盐相对于铵的大量消耗。这些层的化学组成表明存在铵、甲酸盐和硝酸盐的混合物，NH 4 +/（HCOO− +NO3−）摩尔比接近1。这些差异可能与火的类型（燃烧与阴燃）或在向格陵兰岛运输过程中遇到的羽流的气象条件。高分辨率的铵和甲酸盐剖面被用来重建自公元1193年以来到达格陵兰中部的高纬度生物质燃烧输入的频率和强度。格陵兰中部生物质燃烧输入增强的三个时期被确定为：公元1200-1350年，公元1830-1930年，公元1200 -1350年的时间段与中世纪温暖期的特征温暖和干燥的条件相吻合。在小冰期（公元1600-1850年）最冷的时期，生物质燃烧输入不频繁，频率在上个世纪之交增强，然后在整个上个世纪中降低。除了高纬度生物质燃烧，甲酸盐的背景水平在过去的800年中表现出轻微和持续的下降趋势，这可能反映了北美北方植被的恶化。
We have analyzed the soluble portion of impurities trapped in solid precipitation that accumulated at Summit (central Greenland) from 1193 A.D. to the present. Seventy-three ice layers show elevated concentrations of ammonium and formate, caused by high-latitude biomass burning debris reaching Greenland. While a mixture of ammonium and formate close to the molar ratio is generally observed in these ice layers, a large depletion of formate relative to ammonium is found in a few cases. The chemical composition of such layers indicates the presence of a mixture of ammonium, formate, and nitrate with a NH4+/(HCOO− +NO3−) molar ratio close to 1. These differences may be related to the fire type (flaming versus smoldering) or to meteorological conditions encountered by plumes during their transport toward Greenland. The high-resolution ammonium and formate profiles are used to reconstruct the frequency and the intensity of high-latitude biomass burning input having reached central Greenland since 1193 A.D. Three periods of enhanced biomass burning input over central Greenland are identified: 1200–1350 A.D., 1830–1930 A.D., and to a lesser extent 1500–1600 A.D. The 1200–1350 A.D. time period coincides with warm and dry conditions which characterized the Medieval Warm Period. After a period of infrequent biomass burning input during the coldest period of the Little Ice Age (1600–1850 A.D.), the frequency was enhanced at the turn of the last century and then decreased throughout this last century. Aside from high-latitude biomass burning, the background levels of formate show a slight and persistent decreasing trend over the last 800 years probably reflecting the deterioration of the boreal vegetation from North America.