High northern latitude forest fires and vegetation emissions over the last millennium inferred from the chemistry of a central Greenland ice core

• Published in: Journal of Geophysical Research: Atmospheres
• Main Authors: Savarino, Joel, Legrand, Michel
• Other Authors: Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 1998
• Subjects: [SDE]Environmental Sciences; Greenland; Greenland ice core; ice core
• Online Access: https://hal.science/hal-04418175; https://hal.science/hal-04418175/document; https://hal.science/hal-04418175/file/Journal%20of%20Geophysical%20Research%20Atmospheres%20-%201998%20-%20Savarino%20-%20High%20northern%20latitude%20forest%20fires%20and%20vegetation.pdf; https://doi.org/10.1029/97JD03748

International audience 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 NH 4 + /(HCOO − +NO 3 − ) 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.