首页> 外文OA文献 >A 45-year time series of dune mobility indicating constant windiness over the central Sahara
【2h】

A 45-year time series of dune mobility indicating constant windiness over the central Sahara

机译:沙丘活动的45年时间序列表明撒哈拉中部持续刮风

代理获取
本网站仅为用户提供外文OA文献查询和代理获取服务,本网站没有原文。下单后我们将采用程序或人工为您竭诚获取高质量的原文,但由于OA文献来源多样且变更频繁,仍可能出现获取不到、文献不完整或与标题不符等情况,如果获取不到我们将提供退款服务。请知悉。

摘要

Although evidence is mounting that links global warming to changes in atmospheric dynamics over the Atlantic realm, similar studies over the African continent are lacking. And even if such models would exist, it would be difficult to verify their validity due to the paucity of meteorological observations and anemometers in the central Sahara. A pragmatic way around this problem is to monitor barchan dune velocity as a proxy for the windiness of desert areas. Dune migration rates are a measure of the amount of work done by the wind which does not require field measurements but can be observed from space instead. This paper presents a novel application of the remote sensing tool COSI-Corr for the construction of time series of dune mobility from sequences of optical satellite imagery. The technique has been applied to the Bodélé Depression in northern Chad, to demonstrate that dune migration rates in the central Sahara have been remarkably constant for nearly half a century, leading us to conclude that wind velocities have not changed more than 0.2% per year over that period. It is therefore unlikely that the frequency and intensity of dust storms originating from this ‘hot spot’ has significantly changed over the past decades either.
机译:尽管越来越多的证据将全球变暖与大西洋地区的大气动力学变化联系起来,但在非洲大陆却缺乏类似的研究。而且即使存在这样的模型,由于撒哈拉中部的气象观测和风速计都很少,因此很难验证其有效性。解决此问题的一种实用方法是监视沙丘风速,以替代沙漠地区的大风。沙丘迁移率是风的功的量度,不需要实地测量,而是可以从太空观察到。本文介绍了遥感工具COSI-Corr在根据光学卫星图像序列构建沙丘移动性时间序列方面的新应用。该技术已应用于乍得北部的Bodélé洼地,以证明撒哈拉中部的沙丘迁移率在近半个世纪以来一直非常稳定,这使我们得出结论,在过去的一年中,风速变化不超过0.2%那个时期。因此,在过去的几十年中,源自“热点”的沙尘暴的频率和强度也不大可能发生显着变化。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
代理获取

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号