Could gradual changes in Holocene Saharan landscape have caused the observed abrupt shift in North Atlantic dust deposition
Could gradual changes in Holocene Saharan landscape have caused the observed abrupt shift in North Atlantic dust deposition
复制标题
全新世撒哈拉地貌的逐渐变化是否导致了观察到的北大西洋尘埃沉积的突然变化
DOI：
10.1016/j.epsl.2017.06.010
复制
发表时间：
2017
影响因子：
5.3
通讯作者：
T. Stanelle
中科院分区：
文献类型：
--
作者：
S. Egerer;M. Claussen;C. Reick;T. Stanelle
沉积物记录中发现的北大西洋尘埃沉积的突然变化与全新世撒哈拉景观的快速大规模转变有关。我们假设景观的逐渐变化可能导致灰尘沉积的突然变化，要么是因为灰尘激活的非线性，要么是因为主要灰尘源的不均匀分布。为了检验这一假设，我们使用气溶胶气候模型 ECHAM-HAM 研究北大西洋尘埃沉降对全新世期间北非植被和湖泊规定的 1）逐渐且空间均匀的减少和 2）逐渐向南退缩的响应。在我们的模拟中，我们没有发现西北非洲边缘海洋沉积物记录中观察到的灰尘沉积突然增加的证据。我们的结论是，景观的这种逐渐变化不足以解释在海洋沉积物记录中观察到的灰尘积累的突然变化。相反，我们的结果表明，在重要的沙尘源地区，植被和湖泊正在迅速大规模退缩。
The abrupt change in North Atlantic dust deposition found in sediment records has been associated with a rapid large scale transition of Holocene Saharan landscape. We hypothesize that gradual changes in the landscape may have caused this abrupt shift in dust deposition either because of the non-linearity in dust activation or because of the heterogeneous distribution of major dust sources. To test this hypothesis, we investigate the response of North Atlantic dust deposition to a prescribed 1)gradualand spatially homogeneous decrease and 2)gradualsouthward retreat of North African vegetation and lakes during the Holocene using the aerosol-climate model ECHAM-HAM. In our simulations, we do not find evidence of anabruptincrease in dust deposition as observed in marine sediment records along the Northwest African margin. We conclude that such gradual changes in landscape are not sufficient to explain the observedabruptchanges in dust accumulation in marine sediment records. Instead, our results point to arapidlarge-scale retreat of vegetation and lakes in the area of significant dust sources.
影响因子：
6.3
作者：
H. Huang;G. Thomas;R. Grainger
通讯作者：
H. Huang;G. Thomas;R. Grainger