首页 | 本学科首页   官方微博 | 高级检索  
     


Control of wind strength and frequency in the Aral Sea basin during the late Holocene
Authors:Philippe Sorrel, Hedi Oberh  nsli, Nikolaus Boroffka, Danis Nourgaliev, Peter Dulski,Ursula R  hl
Affiliation:aSektion 3.3, GeoForschungsZentrum, Telegraphenberg, D-14473 Potsdam, Germany;bFaculty of Geology, Kazan State University, Kazan, Russia;cDFG Research Center for Ocean Margins (RCOM), Bremen University, Leobener Strasse, D-28359 Bremen, Germany
Abstract:Changing content of detrital input in laminated sediments traced by XRF scanning and microfacies analyses reflect prominent variations in sedimentation processes in the Aral Sea. A high-resolution record of titanium from a core retrieved in the northwestern Large Aral Sea allows a continuous reconstruction of wind strength and frequency in western Central Asia for the past 1500 yr. During AD 450–700, AD 1210–1265, AD 1350–1750 and AD 1800–1975, detrital inputs (bearing titanium) are high, documenting an enhanced early spring atmospheric circulation associated with an increase in intensity of the Siberian High pressure system over Central Asia. In contrast, lower titanium content during AD 1750–1800 and AD 1980–1985 reflects a diminished influence of the Siberian High during early spring with a reduced atmospheric circulation. A moderate circulation characterizes the time period AD 700–1150. Unprecedented weakened atmospheric circulation over western Central Asia are inferred during ca. AD 1180–1210 and AD 1265–1310 with a considerable decrease in dust storm frequency, sedimentation rates, lamination thickness and detrital inputs (screened at 40-μm resolution). Our results are concurrent with changes in the intensity of the Siberian High during the past 1400 yr as reported in the GISP2 Ice Core from Greenland.
Keywords:Chemical composition   Laminated sediments   Wind dynamics   Siberian High   Aral Sea   Late Holocene
本文献已被 ScienceDirect 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号