气候变化领域集成服务门户(CCPortal): Simulation of ash clouds after a Laacher See-type eruption

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DOI	10.5194/cp-17-633-2021
	Simulation of ash clouds after a Laacher See-type eruption
	Niemeier U.; Riede F.; Timmreck C.
发表日期	2021
ISSN	1814-9324
起始页码	555
结束页码	573
卷号	17 期号:2
英文摘要	Dated to approximately 13 000 years ago, the Laacher See (East Eifel volcanic zone) eruption was one of the largest midlatitude Northern Hemisphere volcanic events of the Late Pleistocene. This eruptive event not only impacted local environments and human communities but probably also affected Northern Hemispheric climate. To better understand the impact of a Laacher See-type eruption on NH circulation and climate, we have simulated the evolution of its fine ash and sulfur cloud with an interactive stratospheric aerosol model. Our experiments are based around a central estimate for the Laacher See aerosol cloud of 15 Tg of sulfur dioxide (SO2) and 150 Tg of fine ash, across the main eruptive phases in May and a smaller one in June with 5 Tg SO2 and 50 Tg of fine ash. Additional sensitivity experiments reflect the estimated range of uncertainty of the injection rate and altitude and assess how the solar-absorptive heating from the fine ash emitted in the first eruptive phase changed the volcanic clouds dispersion. The chosen eruption dates were determined by the stratospheric wind fields to reflect the empirically observed ash lobes as derived from geological, paleoecological and archeological evidence linked directly to the prehistoric Laacher See eruption. Whilst our simulations are based on present-day conditions, and we do not seek to replicate the climate conditions that prevailed 13 000 years ago, we consider our experimental design to be a reasonable approximation of the transport pathways in the midlatitude stratosphere at this time of year. Our simulations suggest that the heating of the ash plays an important role for the transport of ash and sulfate. Depending on the altitude of the injection, the simulated volcanic cloud begins to rotate 1 to 3 d after the eruption. This mesocyclone, as well as the additional radiative heating of the fine ash, then changes the dispersion of the cloud itself to be more southward compared to dispersal estimated without fine ash heating. This ash-cloudgenerated southerly migration process may at least partially explain why, as yet, no Laacher See tephra has been found in Greenland ice cores. Sulfate transport is similarly impacted by the heating of the ash, resulting in stronger transport to low latitudes, later arrival of the volcanic cloud in the Arctic regions and a longer lifetime compared to cases without injection of fine ash. Our study offers new insights into the dispersion of volcanic clouds in midlatitudes and addresses a likely behavior of the ash cloud of the Laacher See eruption that darkened European skies at the end of the Pleistocene. In turn, this study can also serve as significant input for scenarios that consider the risks associated with re-awakened volcanism in the Eifel. © This work is distributed under the Creative Commons Attribution 4.0 License.
来源期刊	Climate of the Past
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/183594
作者单位	The Atmosphere in the Earth System, Max Planck Institute for Meteorology, Bundesstr. 53, Hamburg, 20146, Germany; Department of Archaeology and Heritage Studies, Aarhus University Moesgøard, 8270Højbjerg, Denmark
推荐引用方式 GB/T 7714	Niemeier U.,Riede F.,Timmreck C.. Simulation of ash clouds after a Laacher See-type eruption[J],2021,17(2).
APA	Niemeier U.,Riede F.,&Timmreck C..(2021).Simulation of ash clouds after a Laacher See-type eruption.Climate of the Past,17(2).
MLA	Niemeier U.,et al."Simulation of ash clouds after a Laacher See-type eruption".Climate of the Past 17.2(2021).