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The prolonged weak monsoon event in East Asia and the interhemispheric seesaw: implications for persistent AMOC forcing at the mid-late Holocene transition 东亚持续的弱季风事件和半球间的跷跷板:对全新世中晚期过渡时期持续的AMOC强迫的影响
IF 4 1区 地球科学
Global and Planetary Change Pub Date : 2025-09-24 DOI: 10.1016/j.gloplacha.2025.105091
Maoxia Li , Weihong Zhang , Shitao Chen , Jianshun Chen , Yifei Wang , Qingfeng Shao , Yongjin Wang
{"title":"The prolonged weak monsoon event in East Asia and the interhemispheric seesaw: implications for persistent AMOC forcing at the mid-late Holocene transition","authors":"Maoxia Li ,&nbsp;Weihong Zhang ,&nbsp;Shitao Chen ,&nbsp;Jianshun Chen ,&nbsp;Yifei Wang ,&nbsp;Qingfeng Shao ,&nbsp;Yongjin Wang","doi":"10.1016/j.gloplacha.2025.105091","DOIUrl":"10.1016/j.gloplacha.2025.105091","url":null,"abstract":"<div><div>The interhemispheric seesaw at lower latitudes is well established from the last glaciation to the early Holocene. This phenomenon is driven by variations in the Atlantic Meridional Overturning Circulation (AMOC) and the associated latitudinal migration of the Intertropical Convergence Zone (ITCZ). However, the persistence of this phenomenon and the mechanisms involved during the late Holocene, a period characterized by minimal and stable global ice volume, remain unclear. This study presents a new 5.3-year-resolution stalagmite δ<sup>18</sup>O record from central China spanning 4.4–3.0 ka BP. Our data reveal a multi-centennial weak Asian summer monsoon (ASM) event spanning 4.4–3.5 ka BP that is inversely correlated with intensified South American summer monsoon (SASM) activity. This antiphase relationship mirrors the pattern observed during the Little Ice Age (LIA), suggesting a consistent seesaw mechanism. Further analysis shows that an AMOC slowdown coupled with a southward shift in the ITCZ created this hemispheric antiphase during both events. El Niño-like conditions further strengthened the ASM–SASM antiphase relationship during both the 4.4–3.5 ka event and the LIA. Unlike the typical AMOC–solar correlation observed during the LIA, the weakened AMOC during the 4.4–3.5 ka event coincided with strong solar activity. Our results emphasize the persistent seesaw pattern during the mid-to-late Holocene transition, which is driven by changes in the AMOC and El Niño-Southern Oscillation (ENSO) rather than solar activity.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"255 ","pages":"Article 105091"},"PeriodicalIF":4.0,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145221197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Indian summer monsoon variability across the last 9000 years: New evidence from stalagmites of southwestern China 过去9000年来印度夏季风的变化:来自中国西南石笋的新证据
IF 4 1区 地球科学
Global and Planetary Change Pub Date : 2025-09-22 DOI: 10.1016/j.gloplacha.2025.105092
Yanzhen Li , Chunju Huang , Jianghu Lan , David B. Kemp , James G. Ogg , Ashish Sinha , Lvfan Chen , Xiqian Wang , Huiru Tang , Xu Lin , Khalaf H.M. Abdel-Raheem , Rui Zhang , Hai Cheng , R. Lawrence Edwards , Liangcheng Tan
{"title":"Indian summer monsoon variability across the last 9000 years: New evidence from stalagmites of southwestern China","authors":"Yanzhen Li ,&nbsp;Chunju Huang ,&nbsp;Jianghu Lan ,&nbsp;David B. Kemp ,&nbsp;James G. Ogg ,&nbsp;Ashish Sinha ,&nbsp;Lvfan Chen ,&nbsp;Xiqian Wang ,&nbsp;Huiru Tang ,&nbsp;Xu Lin ,&nbsp;Khalaf H.M. Abdel-Raheem ,&nbsp;Rui Zhang ,&nbsp;Hai Cheng ,&nbsp;R. Lawrence Edwards ,&nbsp;Liangcheng Tan","doi":"10.1016/j.gloplacha.2025.105092","DOIUrl":"10.1016/j.gloplacha.2025.105092","url":null,"abstract":"<div><div>The Indian Summer Monsoon (ISM) contains both the Arabian Sea branch (ISM<sub>AS</sub>) and the Bay of Bengal branch (ISM<sub>BOB</sub>), which may act differently during various timescales. Accurately dated, high-resolution climate records from different regions of the ISM domain are needed to fully understand the spatiotemporal variability and dynamic mechanisms of the ISM. Based on high-precision U<img>Th dating chronologies and oxygen isotope (δ<sup>18</sup>O) records of three stalagmites from Shenqi Cave (SQ) from southwestern China, we reconstructed a high-resolution history of the ISM<sub>BOB</sub> over the past 9000 years. Our SQ δ<sup>18</sup>O results demonstrate that the orbital-scale weakening of the Holocene ISM<sub>BOB</sub> was predominantly controlled by changes in Northern Hemisphere summer insolation (NHSI), consistent with the ISM<sub>AS</sub> and EASM record in the broad Asian summer monsoon region. However, in contrast to the strengthening of the ISM<sub>AS</sub> and EASM during the last 2000 years, our δ<sup>18</sup>O record indicates a long-tern weakening trend of the ISM<sub>BOB</sub> during this period. The ISM<sub>BOB</sub> was at its strongest during 9.0–7.5 ka BP, and a rapid weakening occurred between 7.2 and 5.0 ka BP. We propose that the abrupt ISM<sub>BOB</sub> weakening during 7.2–5.0 ka BP may have been linked to high-latitude Northern Hemisphere cooling, which enhanced the interhemispheric temperature gradient and drove a southward migration of the Intertropical Convergence Zone (ITCZ). During the 8.2 ka event, the SQ δ<sup>18</sup>O shows clear positive shifts, indicating transient ISM<sub>BOB</sub> weakening, which rapidly responded to the North Atlantic freshwater forcing. The ISM<sub>BOB</sub> was generally weak during the 4.2 ka event, with two decadal-scale monsoon strengthening intervals.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"255 ","pages":"Article 105092"},"PeriodicalIF":4.0,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145221098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Regional changes of tropical cyclone rainfall in the western North Pacific 北太平洋西部热带气旋降雨的区域变化
IF 4 1区 地球科学
Global and Planetary Change Pub Date : 2025-09-22 DOI: 10.1016/j.gloplacha.2025.105094
Aifang Chen , Yuxin Li , Hao Huang , Cesar Azorin-Molina , Mengqian Lu , Hui-Wen Lai , Penghan Chen , Hong Wang , Junguo Liu
{"title":"Regional changes of tropical cyclone rainfall in the western North Pacific","authors":"Aifang Chen ,&nbsp;Yuxin Li ,&nbsp;Hao Huang ,&nbsp;Cesar Azorin-Molina ,&nbsp;Mengqian Lu ,&nbsp;Hui-Wen Lai ,&nbsp;Penghan Chen ,&nbsp;Hong Wang ,&nbsp;Junguo Liu","doi":"10.1016/j.gloplacha.2025.105094","DOIUrl":"10.1016/j.gloplacha.2025.105094","url":null,"abstract":"<div><div>Tropical cyclones (TCs) in the Western North Pacific (WNP) are the most active globally, and their rainfall threatens lives, infrastructure, and natural ecosystems from oceanic to coastal regions. However, the changing patterns of TC rainfall and the driving mechanisms due to concurrent changes in TC duration and rain rate remain unknown. Here, we find an overall decreasing trend in WNP TC rainfall and contrasting changes between the south (decreases) and north (increases) of 20°N for 1979–2020. The TC duration dominates TC rainfall changes in 63 % of the WNP, mostly occurring in oceanic areas and associated with the poleward migration of TC tracks. In contrast, the TC rain rate dominates TC rainfall changes in the rest of the WNP, especially in northern coastal areas that are closely related to the changes in vertical velocity. Our findings reveal divergent changes in TC rainfall from south to north and systematically explore different controls from ocean to coastal, suggesting escalating regional TC risks in the northern coastal areas.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"255 ","pages":"Article 105094"},"PeriodicalIF":4.0,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145159425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
The 1907 Karatag earthquake doublet in Central Asia: Constraints from historic seismograms and surface rupture analysis 1907年中亚喀拉塔格地震双重波:来自历史地震记录和地表破裂分析的约束
IF 4 1区 地球科学
Global and Planetary Change Pub Date : 2025-09-19 DOI: 10.1016/j.gloplacha.2025.105090
Xiao Yang , Xuhua Shi , Qi Ou , Hanlin Chen , Jin Ge , Feng Li , Mustafo Gadoev , Pulod Aminzoda , Jie Chen , Tao Li , Yangfan Huang
{"title":"The 1907 Karatag earthquake doublet in Central Asia: Constraints from historic seismograms and surface rupture analysis","authors":"Xiao Yang ,&nbsp;Xuhua Shi ,&nbsp;Qi Ou ,&nbsp;Hanlin Chen ,&nbsp;Jin Ge ,&nbsp;Feng Li ,&nbsp;Mustafo Gadoev ,&nbsp;Pulod Aminzoda ,&nbsp;Jie Chen ,&nbsp;Tao Li ,&nbsp;Yangfan Huang","doi":"10.1016/j.gloplacha.2025.105090","DOIUrl":"10.1016/j.gloplacha.2025.105090","url":null,"abstract":"<div><div>Large historical earthquakes in intracontinental collision zones are fundamental for understanding rupture processes, fault interactions and seismic hazards. However, they remain poorly constrained due to the limited availability of instrumental data and inconsistencies in early records. Extracting reliable source parameters and reconstructing rupture dynamics of historical earthquakes therefore represent major challenges in these settings. Here, we re-examine the 1907 M<sub>s</sub> 7.6 Karatag earthquake sequence in Central Asia using an integrated approach that combines digitized analogue seismograms, high-resolution remote sensing and tectonic geomorphology. Our analysis constrains the earthquake epicenter at ∼38.310°N, 67.007°E, with a depth of ∼17 km, a moment magnitude of M<sub>w</sub> 7.3 ± 0.1, and strike–dip–rake angles of 190–210°, 40–60° and 80–160°, respectively. Seismograms from Japan capture two distinct surface waves separated by 21 minutes, confirming a doublet rupture. We interpret the first rupture as occurring on the NE-trending Derbent fault in the Uzbek Gissar, followed by eastward propagation onto the E-trending fault in the Tajik Gissar. The integration of waveform modeling and geomorphic evidence demonstrates how fault linkage and multi-segment rupture govern earthquake evolution in collision zones. Collectively, our results highlight the seismic hazards posed by active faults near densely populated valleys of the Gissar Mountains. Furthermore, this study shows that, when combined with modern geospatial datasets, historical seismograms can recover complex rupture processes and provide broad insights into earthquake dynamics, seismic hazard and fault kinematics in intracontinental orogens worldwide.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"255 ","pages":"Article 105090"},"PeriodicalIF":4.0,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145159424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Resilience of forests to past fire disturbance in the Changbai Mountains, Northeastern China 长白山森林对过去火灾干扰的恢复力
IF 4 1区 地球科学
Global and Planetary Change Pub Date : 2025-09-19 DOI: 10.1016/j.gloplacha.2025.105080
Yutong Qian , Meng Meng , Dongmei Jie , Guizai Gao , Honghao Niu , Zhuo Yang
{"title":"Resilience of forests to past fire disturbance in the Changbai Mountains, Northeastern China","authors":"Yutong Qian ,&nbsp;Meng Meng ,&nbsp;Dongmei Jie ,&nbsp;Guizai Gao ,&nbsp;Honghao Niu ,&nbsp;Zhuo Yang","doi":"10.1016/j.gloplacha.2025.105080","DOIUrl":"10.1016/j.gloplacha.2025.105080","url":null,"abstract":"<div><div>Recent increases in wildfire in many parts of the world have raised awareness of the need to understand what controls post-fire forest resilience. Palaeo-records of fire and vegetation can provide a much needed perspective on ecosystem resilience to fires. Here, we used simulations of forest biomass and tree numbers in response to climate changes and compare these simulations with a 13,000 year long record of fire and vegetation changes from Gushantun (GST) peatland in the Changbai Mountains, to examine the stability and resilience of forest trees after fires. Changes in the characteristics of the fire regime through time were used to explore the consequences of different fire regimes on ecosystems and address the question of which aspects of the fire regime have the highest impact on the degree of disturbance and the loss of forest resilience. Our analyses indicate that the severity and frequency of fires were much higher in the early Holocene than in other periods, and that the study area experienced different types of fire disturbances throughout the period. Fire severity and frequency have a similar impact on forest biomass in the Changbai Mountains, with the largest changes resulting during intervals of frequent severe fires. High severity fires were more destructive to forest openness and were closely related to forest recruitment, while the effect of frequency on openness is not reflected in this study. All species exhibited low stability following high severity fires. Frequent severe fires can cause a shift in forest community composition and loss of resilience.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"255 ","pages":"Article 105080"},"PeriodicalIF":4.0,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145221194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
The enigmatic Norian-Rhaetian boundary: Varying carbon cycle disturbances in continental and deep marine records 神秘的诺里亚-雷蒂亚边界:大陆和深海记录中变化的碳循环干扰
IF 4 1区 地球科学
Global and Planetary Change Pub Date : 2025-09-18 DOI: 10.1016/j.gloplacha.2025.105084
Xia Hua , David B. Kemp , Tenichi Cho , Masayuki Ikeda , Chunju Huang
{"title":"The enigmatic Norian-Rhaetian boundary: Varying carbon cycle disturbances in continental and deep marine records","authors":"Xia Hua ,&nbsp;David B. Kemp ,&nbsp;Tenichi Cho ,&nbsp;Masayuki Ikeda ,&nbsp;Chunju Huang","doi":"10.1016/j.gloplacha.2025.105084","DOIUrl":"10.1016/j.gloplacha.2025.105084","url":null,"abstract":"<div><div>The Norian-Rhaetian transition (late Sevatian through early Rhaetian) was associated with a series of faunal turnovers and a putative global carbon cycle perturbation, as evidenced by one or more negative carbon isotope excursions (NCIEs) that occur in locations around the world. Deciphering the pattern, timing and causes of these NCIEs is crucial for understanding the characteristics and causal mechanisms of environmental change across the Norian-Rhaetian boundary (NRB). Currently, however, there is no agreed position and definition of the NRB. Moreover, records of the Sevatian-early Rhaetian from terrestrial and deep marine sites are largely uninvestigated. Here we present organic carbon isotope (δ<sup>13</sup>C<sub>org</sub>) and associated geochemical data across upper Norian to lower Rhaetian strata from a non-marine section at St Audrie's Bay, UK (west European lacustrine basin) and a pelagic deep-marine section at Katsuyama, Japan (central Panthalassa Ocean). Both sites show putative NCIEs, but they were likely of different ages. At St. Audrie's Bay, a cluster of NCIEs (maximum magnitude of −3.5 ‰) likely span between ∼207.6 Ma and ∼ 206.6 Ma based on paleomagnetically-calibrated astronomical time constraints, whereas smaller magnitude NCIEs (maximum magnitude of −2 ‰) at Katsuyama were likely older (∼210 Ma). Our new data underline the probable multi-phased nature of Sevatian-early Rhaetian carbon cycle changes, and also help to demonstrate that differences in NCIE magnitudes in different locations were at least in part linked to varying relative amounts of terrestrial and marine organic matter. Hg enrichment within the NCIE interval at Katsuyama supports the emerging view that volcanism was a driver of carbon cycle disturbance near the base of the Rhaetian.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"255 ","pages":"Article 105084"},"PeriodicalIF":4.0,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145159423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
The stability of grassland spring phenology to extreme drought is modulated by radiation and biodiversity on the Tibetan Plateau
IF 4 1区 地球科学
Global and Planetary Change Pub Date : 2025-09-17 DOI: 10.1016/j.gloplacha.2025.105088
Wendu Rina , Yangjian Zhang , Xianzhou Zhang , Yunlong He , Ge Hou , Wenchao Wu , Wenyu Li , Lin Jiang , Juntao Zhu
{"title":"The stability of grassland spring phenology to extreme drought is modulated by radiation and biodiversity on the Tibetan Plateau","authors":"Wendu Rina ,&nbsp;Yangjian Zhang ,&nbsp;Xianzhou Zhang ,&nbsp;Yunlong He ,&nbsp;Ge Hou ,&nbsp;Wenchao Wu ,&nbsp;Wenyu Li ,&nbsp;Lin Jiang ,&nbsp;Juntao Zhu","doi":"10.1016/j.gloplacha.2025.105088","DOIUrl":"10.1016/j.gloplacha.2025.105088","url":null,"abstract":"<div><div>Long-term trends of vegetation spring phenology (i.e., start of season, SOS) under ongoing climate change have received widespread attention due to its implication for ecosystem carbon balance. However, the stability of SOS under short-term disturbance, such as extreme drought event, remains poorly understood. Here, we assessed the geographic patterns of SOS stability, encompassing multiple components (resistance, resilience, and temporal stability), in response to preseason extreme drought events using satellite-observed vegetation index and gridded drought index across the alpine grasslands of the Tibetan Plateau (TP). Higher resistance and temporal stability of SOS were generally observed in the meadow-dominated eastern TP, with declining westward along longitudinal gradients. Whereas, the resilience of SOS peaked in the semi-arid central plateau. The spatial coherence between resistance and temporal stability suggests that the consistency of SOS during drought periods (i.e., temporal stability) critically depends on its capacity to resist drought (i.e., resistance). The geographical detector model revealed that radiation and biodiversity were the primary drivers of the spatial distributions of SOS resistance and temporal stability, with higher resistance and temporal stability associated with lower radiation and greater biodiversity. In contrast, the contribution of environmental settings to SOS resilience was relatively lower than that of resistance, with a spatial trade-off between resistance and resilience across the TP, except in the western regions, where a distinct low resistance-low resilience pattern was observed. Overall, our findings provide novel insights into ecosystem stability under extreme droughts, and improve the representation of drought responses in alpine ecosystem within land surface models.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"255 ","pages":"Article 105088"},"PeriodicalIF":4.0,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145093914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Bottom water characteristics and paleoceanographic evolution of Central Southern Pacific Ocean across the Mid-Brunhes Transition 中-布伦什过渡带中南太平洋底水特征与古海洋学演化
IF 4 1区 地球科学
Global and Planetary Change Pub Date : 2025-09-16 DOI: 10.1016/j.gloplacha.2025.105087
N. Mahanta, B. Sahoo, Sunil K. Das, S. Datta, S. Rath, Raj K. Singh
{"title":"Bottom water characteristics and paleoceanographic evolution of Central Southern Pacific Ocean across the Mid-Brunhes Transition","authors":"N. Mahanta,&nbsp;B. Sahoo,&nbsp;Sunil K. Das,&nbsp;S. Datta,&nbsp;S. Rath,&nbsp;Raj K. Singh","doi":"10.1016/j.gloplacha.2025.105087","DOIUrl":"10.1016/j.gloplacha.2025.105087","url":null,"abstract":"<div><div>The varying strength and length of historical and forthcoming interglacial periods hold significant relevance for human society. The interglacials occurring after the Mid-Brunhes Transition (MBT; ∼430 kyr) displayed warmer temperatures and elevated CO<sub>2</sub> in the atmosphere compared to those preceding that period. However, the reason behind this climatic shift remains under debate. Here, we have analysed sediment core samples from International Ocean Discovery Program Site U1540 located in the Central South Pacific to study the assemblages of benthic and planktic foraminifera, as well as Iceberg-rafted debris (IRD), in order to understand the causes of increased atmospheric CO<sub>2</sub> during interglacial periods following the MBT. During the pre-MBT interglacials, CSP bottom water was more oxic, and corrosive marked by a higher abundance of highly oxic and corrosive-resistant Antarctic Bottom Water (AABW) indicator species <em>Nuttallides umbonifera</em> (%), which reduced significantly during and post-MBT interglacials. This study suggests that the influence of AABW decreases during MIS 11 and other interglacials after the MBT, which is marked by ∼10 % reduction in oxic benthic foraminifera species (%) and <em>N. umbonifera</em> (%) as compared to the pre-MBT interglacials. This reduction in AABW volume might have influenced the sequestration of atmospheric CO<sub>2</sub> in the deep ocean, leading to an increase of ∼30 ppm in atmospheric CO<sub>2</sub> during and after the MBT interglacials compared to levels before the MBT. During post-MBT interglacials, a significant reduction in sea-ice and icebergs shoaled the thermocline, which is marked by minimal IRD and abundance of <em>Globoconella inflata</em>. The oxygenated Lower Circumpolar Deep Water follows the Antarctic Circumpolar Current strength and shows 100 kyr periodicity in bottom water current strength.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"255 ","pages":"Article 105087"},"PeriodicalIF":4.0,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145093915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Circulation changes in the Mediterranean Sea over the last 30,000 years – Constraints from deep-water Nd isotopes 过去3万年地中海环流的变化——来自深水Nd同位素的限制
IF 4 1区 地球科学
Global and Planetary Change Pub Date : 2025-09-16 DOI: 10.1016/j.gloplacha.2025.105086
Yan Zhang , Jiawang Wu , Christophe Colin , Guohui Gao , Huang Huang , Marcus Gutjahr , Qiong Wu , Zhifei Liu , Katharina Pahnke , Gert J. de Lange
{"title":"Circulation changes in the Mediterranean Sea over the last 30,000 years – Constraints from deep-water Nd isotopes","authors":"Yan Zhang ,&nbsp;Jiawang Wu ,&nbsp;Christophe Colin ,&nbsp;Guohui Gao ,&nbsp;Huang Huang ,&nbsp;Marcus Gutjahr ,&nbsp;Qiong Wu ,&nbsp;Zhifei Liu ,&nbsp;Katharina Pahnke ,&nbsp;Gert J. de Lange","doi":"10.1016/j.gloplacha.2025.105086","DOIUrl":"10.1016/j.gloplacha.2025.105086","url":null,"abstract":"<div><div>The Mediterranean circulation is sensitive to ongoing climate change, and played a key role in the rhythmic deposition of organic-rich sedimentary layers, known as sapropels. These deposits represent periods of anoxic deep-water phases in the geologic past. However, many aspects of their interactions with climatic and oceanographic processes are unresolved. Here, we integrate a novel offshore record of Nd isotope composition (εNd) with authigenic εNd data from multiple Mediterranean sites and use a refined box model, to resolve mixing and advection of Mediterranean deep water over the last ∼30,000 years. During the Last Glacial Maximum, more unradiogenic εNd (−7.4 to −6.5) in the deep EMS corresponds to a 56 % ± 14 % decline in water exchange between the eastern and western Mediterranean Sea (EMS vs. WMS). This decline was caused by lower sea levels, which also led to distinct deep circulation modes in the two basins. Meanwhile, deep convection occurred in the Ionian Sea, implying a shift of EMS deep-water formation zone. The Heinrich Stadial 1 is characterized by increased εNd values, showing a strong intermediate-water outflow caused by deglacial sea-level rise, but the deep EMS circulation weakened. The more radiogenic and homogeneous εNd (−5.3 to −4.7) during sapropel S1 deposition suggest deep-water stagnation in the EMS. This was accompanied by enhanced Nile runoff and 44 % reduced EMS–WMS exchange that was limited to shallower depths, with weak but persistent outflow from the Adriatic Sea. Such basin-wide stagnation initiated ∼1000 years before the onset of S1 and terminated with full deep-water renewal during S1 ending.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"255 ","pages":"Article 105086"},"PeriodicalIF":4.0,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145093931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Global mapping of canopy conductance from TROPOMI solar-induced chlorophyll fluorescence after differentiating contributions of sunlit and shaded leaves 基于TROPOMI太阳诱导叶绿素荧光的冠层电导全球制图在区分光照和遮荫叶片的贡献后
IF 4 1区 地球科学
Global and Planetary Change Pub Date : 2025-09-16 DOI: 10.1016/j.gloplacha.2025.105089
Xiaoping Wang , Wei He
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