摘要
年代际尺度气候变化是地球气候系统的重要特征,受中纬西风环流控制的中亚西风区在该尺度的研究仍存在不足,尤其是全球变暖背景下其水文气候年代际变化机制尚不明确。因此,系统研究中亚西风区近数百年水文气候年代际演变特征,对于理解全球变暖背景下区域气候效应及其驱动机制具有重要意义。本文系统梳理中亚西风区东部树轮、冰芯、湖泊沉积、石笋等46条高分辨率地质记录,结合多窗谱分析等方法,综合探讨小冰期以来该区域水文气候年代际变化的时空特征与驱动机制。研究发现,中亚西风区东部小冰期水文气候变化存在10~35 a和45~82 a的年代际气候周期,现代暖期则以10~35 a周期为主,且区域内部呈现显著空间差异,现代暖期整体表现为暖湿化趋势。小冰期-现代暖期转换期(1800—1920 AD)普遍存在“干旱-湿润-干旱”的年代际转型过程,其中1910s极端干旱事件具有区域普遍性。太阳活动调控的北大西洋涛动相位变化和中纬西风环流南-北摆动对该区域水文气候年代际变化起了主导作用,火山活动对极端事件存在调制效应,而人类活动可能对现代暖湿化起了更重要贡献。本研究为理解中亚西风区气候对全球变化的响应机制提供了多载体证据,未来需结合更多高分辨率地质记录与数值模拟方法,进一步量化自然与人类活动对水文气候年代际变化的贡献。
The decadal-scale climate change represents a critical feature of the Earth’s climate system.However,investigations into the decadal hydroclimate dynamics in the westerlies-dominated Central Asia—governed by the mid-latitude westerly circulation—remain incomplete,particularly concerning the mechanistic shifts in decadal hydroclimate patterns under global warming.Therefore,systematically resolving the decadal hydroclimate evolution in the past several centuries in this region is pivotal for deciphering regional climate responses and underlying drivers in the context of global warming.We synthesized 46 high-resolution geological records from tree rings,ice cores,lake sediments,and stalagmites,in the eastern part of the westerlies-dominated Central Asia.By integrating multi-taper method(MTM)analysis and complementary methodologies,we comprehensively characterized the spatiotemporal signatures and the driving mechanisms of decadal hydroclimate variations since the Little Ice Age.Our findings reveal that decadal hydroclimate during the Little Ice Age exhibited dual cyclicities of 10~35 years and 45~82 years,whereas the Current Warm Period was dominated by 10~35-year cycle.Pronounced spatial heterogeneities were observed across the regions,with a consistent warm-wetting trend in the Current Warm Period.The transition(1800—1920 AD)was marked by an overall decadal“drought-wet-drought”transition process,with the 1910s extreme drought event showed regional universality.The solar activitymodulated the North Atlantic Oscillation(NAO)phase shifts and meridional excursions of the mid-latitude westerlies played a pivotal role in the decadal variations of the regional hydroclimate,while volcanic activities modulated extreme events.The warm-wetting trend in the Current Warm Period reflects enhanced human influences.This research provided multi-proxy evidence for understanding climate response mechanisms of the Central Asian westerlies under global change.Future efforts shall integrate high-resolution geological archives with numerical simulations to quantify the contributions of natural versus anthropogenic factors to decadal hydroclimate dynamics.
作者
李浩然
蓝江湖
程鹏
Kashif Hayat
吴小辉
王乐
田绒
李建森
郑艳红
LI Haoran;LAN Jianghu;CHENG Peng;Kashif Hayat;WU Xiaohui;WANG Le;TIAN Rong;LI Jiansen;ZHENG Yanhong(State Key Laboratory of Continental Evolution and Early Life,Department of Geology,Northwest University,Xi’an 710069,China;State Key Laboratory of Loess Science,Institute of Earth Environment,Chinese Academy of Sciences,Xi’an 710061,China;University of Chinese Academy of Sciences,Beijing 100049,China;Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources,Qinghai Institute of Salt Lakes,Chinese Academy of Sciences,Xining 810008,China)
出处
《海洋地质与第四纪地质》
北大核心
2025年第5期79-103,共25页
Marine Geology & Quaternary Geology
基金
国家自然科学基金资助项目“小冰期以来湖泊记录的我国西北地区水文气候年代际变化特征”(42273060)
陕西省杰出青年科学基金资助项目(2024JC-JCQN-36)
第二次青藏高原综合科学考察项目“末次间冰期以来西风-季风演化规律和机理”(2019QZKK0101)
中国科学院青年创新促进会会员项目(2021411)。
关键词
小冰期
现代暖期
水文气候
年代际
中亚西风区
Little Ice Age
current warm period
hydroclimate variation
decadal-scale
westerlies-dominated central Asia
