Pub Date : 2025-02-01DOI: 10.1016/j.gloplacha.2024.104669
Y. Nuñez-Bolaño , N. Hoyos , A. Correa-Metrio , C. Martínez , C. Pizano , J. Escobar , C. Huertas , C. Jaramillo
Disentangling the environmental determinants of tropical biomes is crucial for understanding their response to climate change. This study investigated the effect of climate and soil-related variables on biome transitions in the Caribbean region of Colombia and Panama, focusing on xerophytic forest (XF), tropical dry forest (TDF), and tropical rainforest (TRF). We analyzed the climatic variables at different time scales (daily, seasonal, and annual) and their interaction with soil properties. We performed an ordinal logistic regression to assess the combined effect of the most important variables in biome transitions. Our results showed that climate variables are major discriminators in our study region, particularly precipitation at a seasonal and annual scale. The ordinal logistic regression highlighted the significance of annual precipitation and dry-season length in biome transitions, with maximum temperature impacting TDF-TRF transitions. Soil differences, although present (e.g., higher sand content in XF), played a marginal role. Overall, our findings emphasize the dominance of climate over soil in shaping tropical biome distributions in the northern Caribbean part of South America. These findings contribute to a deeper understanding of tropical biome responses to climate change.
{"title":"Influence of climatic variables on biome transitions in the Colombian and Panamanian Caribbean region","authors":"Y. Nuñez-Bolaño , N. Hoyos , A. Correa-Metrio , C. Martínez , C. Pizano , J. Escobar , C. Huertas , C. Jaramillo","doi":"10.1016/j.gloplacha.2024.104669","DOIUrl":"10.1016/j.gloplacha.2024.104669","url":null,"abstract":"<div><div>Disentangling the environmental determinants of tropical biomes is crucial for understanding their response to climate change. This study investigated the effect of climate and soil-related variables on biome transitions in the Caribbean region of Colombia and Panama, focusing on xerophytic forest (XF), tropical dry forest (TDF), and tropical rainforest (TRF). We analyzed the climatic variables at different time scales (daily, seasonal, and annual) and their interaction with soil properties. We performed an ordinal logistic regression to assess the combined effect of the most important variables in biome transitions. Our results showed that climate variables are major discriminators in our study region, particularly precipitation at a seasonal and annual scale. The ordinal logistic regression highlighted the significance of annual precipitation and dry-season length in biome transitions, with maximum temperature impacting TDF-TRF transitions. Soil differences, although present (e.g., higher sand content in XF), played a marginal role. Overall, our findings emphasize the dominance of climate over soil in shaping tropical biome distributions in the northern Caribbean part of South America. These findings contribute to a deeper understanding of tropical biome responses to climate change.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"245 ","pages":"Article 104669"},"PeriodicalIF":4.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142797880","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}
Pub Date : 2025-02-01DOI: 10.1016/j.gloplacha.2024.104681
Jinlong Du , Jun Tian , Aixue Hu , Yongqiang Yu , Baohuang Su , Dabang Jiang
The presence of the Tibetan Plateau is believed to lower pCO2atm by stimulating weathering carbon sink, during which the global ocean is considered a passive carbon reservoir despite the tremendous marine carbon inventory. Yet, recent studies reveal that the orographic forcing of the Tibetan Plateau could lead to drastic changes in ocean circulation, which would substantially affect basin-scale carbon storage and hence pCO2atm. However, this connection between the presence of the Tibetan Plateau and changes in the oceanic carbon inventory remains insufficiently investigated. Here, by employing a state-of-the-art ocean-biogeochemical model, we explore the role of the Tibetan Plateau in determining basin-scale carbon storage patterns based on an idealized experimental design. We find that the presence of the Tibetan Plateau substantially enhances deep Pacific carbon storage and hence lowers pCO2atm via essential reorganization of the meridional overturning circulation, particularly associated with the development of the Pacific halocline. Moreover, the presence of the Tibetan Plateau greatly affects the oceanic carbon uptake in the Northern Hemisphere, which is likely controlled by the variations in surface alkalinity.
{"title":"The presence of the Tibetan Plateau lowers atmospheric CO2 levels via the Atlantic-Pacific carbon seesaw","authors":"Jinlong Du , Jun Tian , Aixue Hu , Yongqiang Yu , Baohuang Su , Dabang Jiang","doi":"10.1016/j.gloplacha.2024.104681","DOIUrl":"10.1016/j.gloplacha.2024.104681","url":null,"abstract":"<div><div>The presence of the Tibetan Plateau is believed to lower <em>p</em>CO<sub>2</sub><sup>atm</sup> by stimulating weathering carbon sink, during which the global ocean is considered a passive carbon reservoir despite the tremendous marine carbon inventory. Yet, recent studies reveal that the orographic forcing of the Tibetan Plateau could lead to drastic changes in ocean circulation, which would substantially affect basin-scale carbon storage and hence <em>p</em>CO<sub>2</sub><sup>atm</sup>. However, this connection between the presence of the Tibetan Plateau and changes in the oceanic carbon inventory remains insufficiently investigated. Here, by employing a state-of-the-art ocean-biogeochemical model, we explore the role of the Tibetan Plateau in determining basin-scale carbon storage patterns based on an idealized experimental design. We find that the presence of the Tibetan Plateau substantially enhances deep Pacific carbon storage and hence lowers <em>p</em>CO<sub>2</sub><sup>atm</sup> via essential reorganization of the meridional overturning circulation, particularly associated with the development of the Pacific halocline. Moreover, the presence of the Tibetan Plateau greatly affects the oceanic carbon uptake in the Northern Hemisphere, which is likely controlled by the variations in surface alkalinity.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"245 ","pages":"Article 104681"},"PeriodicalIF":4.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142884639","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}
Pub Date : 2025-02-01DOI: 10.1016/j.gloplacha.2025.104693
Tony Reimann , Christine Heim , Dietmar Quandt , Tibor J. Dunai , Martin Melles , Benedikt Ritter
The availability of water influences the evolution of life as well as the evolution of the Earth's land surface. Until recently, role of geomorphological and biological (geo-bio) processes including their interactions and inferred co-evolution have been poorly understood for extremely water-limited (hyper-arid) environments. This emerging field lies at the nexus of weathering, soil (crust) formation and erosion but also involves landform evolution, which creates barriers or corridors for life across varied geological time scales. To address the complex issues that arise from this field, the German Research Foundation (DFG) has funded Collaborative Research Centre CRC1211 (Earth–Evolution at the Dry Limit) through interdisciplinary research. The natural laboratories used for this work are the hyper-arid cores of the Atacama and Namib deserts, and the main objective has been to gain improved understanding of the evolution of the geosphere and biosphere in hyper-arid environments and to evaluate interactions between these spheres. We hypothesize that phases or events of higher water-availability (by fog, dew or rain) are the key drivers of geo-bio co-evolution. Furthermore, we hypothesize that barriers of geological, geomorphological, and climatic origin are the main controls on present-day biodiversity at various heirarchies including ecosystem dynamics. To test these hypotheses, the studies reported in this virtual special issue (VSI) combine expertise from the fields of population and (phylo-) genetics, molecular biology, biogeography, ecology, soil sciences, geomorphology, meteorology, (palaeo-) climatology, (isotope-) geochemistry and geochronology to shed new light on the trajectories and thresholds of the evolution and isolation of life. This article collection reports recent progress in the hope of motivating and inspiring scientists from all over the world to collaborate on a more comprehensive and quantitative understanding of dry-limited systems, with a view to implementing this understanding into overarching Earth system models.
{"title":"Editorial preface to special issue: Earth-evolution at the Dry Limit","authors":"Tony Reimann , Christine Heim , Dietmar Quandt , Tibor J. Dunai , Martin Melles , Benedikt Ritter","doi":"10.1016/j.gloplacha.2025.104693","DOIUrl":"10.1016/j.gloplacha.2025.104693","url":null,"abstract":"<div><div>The availability of water influences the evolution of life as well as the evolution of the Earth's land surface. Until recently, role of geomorphological and biological (geo-bio) processes including their interactions and inferred co-evolution have been poorly understood for extremely water-limited (hyper-arid) environments. This emerging field lies at the nexus of weathering, soil (crust) formation and erosion but also involves landform evolution, which creates barriers or corridors for life across varied geological time scales. To address the complex issues that arise from this field, the German Research Foundation (DFG) has funded Collaborative Research Centre CRC1211 (<em>Earth–Evolution at the Dry Limit</em>) through interdisciplinary research. The natural laboratories used for this work are the hyper-arid cores of the Atacama and Namib deserts, and the main objective has been to gain improved understanding of the evolution of the geosphere and biosphere in hyper-arid environments and to evaluate interactions between these spheres. We hypothesize that phases or events of higher water-availability (by fog, dew or rain) are the key drivers of geo-bio co-evolution. Furthermore, we hypothesize that barriers of geological, geomorphological, and climatic origin are the main controls on present-day biodiversity at various heirarchies including ecosystem dynamics. To test these hypotheses, the studies reported in this virtual special issue (VSI) combine expertise from the fields of population and (phylo-) genetics, molecular biology, biogeography, ecology, soil sciences, geomorphology, meteorology, (palaeo-) climatology, (isotope-) geochemistry and geochronology to shed new light on the trajectories and thresholds of the evolution and isolation of life. This article collection reports recent progress in the hope of motivating and inspiring scientists from all over the world to collaborate on a more comprehensive and quantitative understanding of dry-limited systems, with a view to implementing this understanding into overarching Earth system models.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"245 ","pages":"Article 104693"},"PeriodicalIF":4.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142975644","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}
Pub Date : 2025-02-01DOI: 10.1016/j.gloplacha.2024.104689
Reema Kasera, Vijay K. Minocha
The adverse impact of El Niño on Indian summer monsoon rainfall (ISMR) is well established, with documented physical mechanisms linking different flavors of El Niño and ISMR. However, few studies have discussed the pathways that connect different onsets of El Niño and ISMR. The present study identifies the two ENSO categories (spring and summer) depending on the occurrence time of positive sea surface temperature anomalies (SSTA) in the Niño-3.4 region of the Pacific Ocean. The distinct impacts of these El Niño types on ISMR were investigated by analyzing extensive composites of rainfall anomalies, Sea Surface Temperature (SST) patterns, and atmospheric circulation dynamics. It was found that the Indian region experiences a significant average negative deviation of 26 % from normal rainfall across 30 % of the country during spring El Niño (SPE) (February to May). Whereas a summer El Niño (SUE) (June to September) is distinguished by a significant negative deviation over 15 % of the Indian region with an average deviation of 22 % across the country. SPE events showed strong warmth with an average of 1.27 °C, while SUE events had milder warmth, averaging 0.84 °C. Further, a strong positive Indian Ocean dipole (IOD) phenomenon was observed during the SPE event, which was associated with a strong easterly wind. This positive IOD phenomenon was progressively developed from June to September, heading to the establishment of low pressure over Western Indian Ocean (WIO), resulting in altered or weakened Walker circulation. The study elucidates the intricate interaction between El Niño events and the Indian monsoon system, providing a vital understanding of the mechanisms that govern seasonal rainfall variability across the Indian subcontinent.
El Niño对印度夏季季风降雨（ISMR）的不利影响已得到证实，有文献记录的物理机制将不同类型的El Niño与ISMR联系起来。然而，很少有研究讨论连接El Niño和ISMR不同发病的途径。根据太平洋Niño-3.4区域正海温异常（SSTA）的发生时间，本研究确定了两个ENSO类别（春季和夏季）。通过分析降雨异常、海温模式和大气环流动力学的广泛组合，研究了这些El Niño类型对ISMR的不同影响。研究发现，在春季El Niño (SPE)（2月至5月）期间，印度地区与全国30%的地区的正常降雨量平均负偏差为26%。而夏季厄尔尼诺Niño (SUE)（6月至9月）在印度地区的显著负偏差超过15%，全国平均偏差为22%。SPE事件表现出较强的升温，平均为1.27°C，而SUE事件表现出较弱的升温，平均为0.84°C。此外，SPE事件期间观测到强烈的印度洋正偶极子（IOD）现象，该现象与强烈的东风有关。从6月到9月，这一正IOD现象逐渐发展，走向西印度洋（WIO）低压的建立，导致Walker环流改变或减弱。该研究阐明了El Niño事件与印度季风系统之间复杂的相互作用，为理解控制整个印度次大陆季节性降雨变化的机制提供了重要的理解。
{"title":"Impact of El Niño onset timing on Indian Monsoon Rainfall patterns","authors":"Reema Kasera, Vijay K. Minocha","doi":"10.1016/j.gloplacha.2024.104689","DOIUrl":"10.1016/j.gloplacha.2024.104689","url":null,"abstract":"<div><div>The adverse impact of El Niño on Indian summer monsoon rainfall (ISMR) is well established, with documented physical mechanisms linking different flavors of El Niño and ISMR. However, few studies have discussed the pathways that connect different onsets of El Niño and ISMR. The present study identifies the two ENSO categories (spring and summer) depending on the occurrence time of positive sea surface temperature anomalies (SSTA) in the Niño-3.4 region of the Pacific Ocean. The distinct impacts of these El Niño types on ISMR were investigated by analyzing extensive composites of rainfall anomalies, Sea Surface Temperature (SST) patterns, and atmospheric circulation dynamics. It was found that the Indian region experiences a significant average negative deviation of 26 % from normal rainfall across 30 % of the country during spring El Niño (SPE) (February to May). Whereas a summer El Niño (SUE) (June to September) is distinguished by a significant negative deviation over 15 % of the Indian region with an average deviation of 22 % across the country. SPE events showed strong warmth with an average of 1.27 °C, while SUE events had milder warmth, averaging 0.84 °C. Further, a strong positive Indian Ocean dipole (IOD) phenomenon was observed during the SPE event, which was associated with a strong easterly wind. This positive IOD phenomenon was progressively developed from June to September, heading to the establishment of low pressure over Western Indian Ocean (WIO), resulting in altered or weakened Walker circulation. The study elucidates the intricate interaction between El Niño events and the Indian monsoon system, providing a vital understanding of the mechanisms that govern seasonal rainfall variability across the Indian subcontinent.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"245 ","pages":"Article 104689"},"PeriodicalIF":4.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142905665","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}
Pub Date : 2025-02-01DOI: 10.1016/j.gloplacha.2024.104690
Wei Shang , Keqin Duan , Wei Yu , Li Xing , Peihong Shi
The freezing level height (FLH) reflects the thermal conditions in the troposphere and implies cryospheric changes on the Tibetan Plateau (TP). This study aims to understand whether variations in the FLH over the TP are linked to midlatitude and tropical signals, which is currently unknown. An empirical orthogonal function analysis is utilized to investigate the east-west dipole pattern of the summer FLH over the TP during the period of 1961–2019. The results show that the dipole pattern of the FLH is mainly associated with the circumglobal teleconnection (CGT) waves, propagating from the North Atlantic Ocean to East Asia. A pair of anomalous cyclone and anticyclone related to the CGT pattern is observed, in favor for cooling and warming over the western and eastern TP, respectively. The thermodynamic equation diagnosis demonstrate that the CGT-related upward and downward motions accompanied by adiabatic cooling and heating, primarily contribute to the decreases and increases of FLH. As the thermal effect of the east-west dipole FLH occurs, the CGT waves are strengthened downstream to North Pacific and North America. Meanwhile, the lower-level easterly anomalies and westerly anomalies winds appear over the Indian Ocean and tropical Pacific. From summer to the following winter, anomalous westerly winds persistently prevail over the tropical Pacific, weakening the Walker circulation and leading to subsequent El Niño–Southern Oscillation (ENSO) events. Without the dipole mode of the TP FLH impact, the CGT-ENSO relationship could be weakened. The results suggest that the dipole pattern of the TP FLH acts as a linking bridge between the CGT pattern and ENSO events, which also verify the key role of TP in connecting the midlatitude and tropical climate variabilities.
{"title":"Influence of the circumglobal teleconnection on the following ENSO: From the perspective of the freezing level height over the Tibetan Plateau","authors":"Wei Shang , Keqin Duan , Wei Yu , Li Xing , Peihong Shi","doi":"10.1016/j.gloplacha.2024.104690","DOIUrl":"10.1016/j.gloplacha.2024.104690","url":null,"abstract":"<div><div>The freezing level height (FLH) reflects the thermal conditions in the troposphere and implies cryospheric changes on the Tibetan Plateau (TP). This study aims to understand whether variations in the FLH over the TP are linked to midlatitude and tropical signals, which is currently unknown. An empirical orthogonal function analysis is utilized to investigate the east-west dipole pattern of the summer FLH over the TP during the period of 1961–2019. The results show that the dipole pattern of the FLH is mainly associated with the circumglobal teleconnection (CGT) waves, propagating from the North Atlantic Ocean to East Asia. A pair of anomalous cyclone and anticyclone related to the CGT pattern is observed, in favor for cooling and warming over the western and eastern TP, respectively. The thermodynamic equation diagnosis demonstrate that the CGT-related upward and downward motions accompanied by adiabatic cooling and heating, primarily contribute to the decreases and increases of FLH. As the thermal effect of the east-west dipole FLH occurs, the CGT waves are strengthened downstream to North Pacific and North America. Meanwhile, the lower-level easterly anomalies and westerly anomalies winds appear over the Indian Ocean and tropical Pacific. From summer to the following winter, anomalous westerly winds persistently prevail over the tropical Pacific, weakening the Walker circulation and leading to subsequent El Niño–Southern Oscillation (ENSO) events. Without the dipole mode of the TP FLH impact, the CGT-ENSO relationship could be weakened. The results suggest that the dipole pattern of the TP FLH acts as a linking bridge between the CGT pattern and ENSO events, which also verify the key role of TP in connecting the midlatitude and tropical climate variabilities.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"245 ","pages":"Article 104690"},"PeriodicalIF":4.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142935467","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}
Pub Date : 2025-02-01DOI: 10.1016/j.gloplacha.2024.104691
Jimin Sun , Weiguo Liu , Brian F. Windley , Longxiao Xu , Tongyan Lü
The Junggar Basin, located in mid-latitude Central Asia, is an inland basin that is one of the remotest area from any open seas on Earth. Knowledge about the paleoclimatic change and the relevant driving factors in this specific geographical region is critically important for understanding the Cenozoic aridification processes in the Asian hinterland. In this study, we focused on Miocene strata in the northwestern Junggar Basin, which consist of middle Miocene fluviolacustrine sediments and a late Miocene aeolian/reworked red clay. Our data of the paleoclimatic indices of color index, magnetic susceptibility and stable isotopes indicate a middle Miocene warm humid climate between 17.5 and 14 Ma, and a subsequent shift to an arid climate after 14 Ma. This paleoclimatic shift was synchronous with a biotic turnover marked by a transition from a high degree of mammal diversity dominated by large-sized mammals living in a humid forest grassland during the Middle Miocene Climatic Optimum to a late Miocene small-sized mammal-dominant fauna living in dry open steppe. The above correlations imply an intrinsic link between environmental change and biotic evolution. We suggest that a decrease in sea surface temperature and the westward retreat of Paratethys induced by global cooling were the key factors responsible for the enhanced aridity of the Asian inland after 14 Ma, which controlled the reduced water vapor transported by the Westerlies to the interior of Asia.
{"title":"Enhanced aridity in the interior of Asia after the Middle Miocene Climatic Optimum driven by global cooling","authors":"Jimin Sun , Weiguo Liu , Brian F. Windley , Longxiao Xu , Tongyan Lü","doi":"10.1016/j.gloplacha.2024.104691","DOIUrl":"10.1016/j.gloplacha.2024.104691","url":null,"abstract":"<div><div>The Junggar Basin, located in mid-latitude Central Asia, is an inland basin that is one of the remotest area from any open seas on Earth. Knowledge about the paleoclimatic change and the relevant driving factors in this specific geographical region is critically important for understanding the Cenozoic aridification processes in the Asian hinterland. In this study, we focused on Miocene strata in the northwestern Junggar Basin, which consist of middle Miocene fluviolacustrine sediments and a late Miocene aeolian/reworked red clay. Our data of the paleoclimatic indices of color index, magnetic susceptibility and stable isotopes indicate a middle Miocene warm humid climate between 17.5 and 14 Ma, and a subsequent shift to an arid climate after 14 Ma. This paleoclimatic shift was synchronous with a biotic turnover marked by a transition from a high degree of mammal diversity dominated by large-sized mammals living in a humid forest grassland during the Middle Miocene Climatic Optimum to a late Miocene small-sized mammal-dominant fauna living in dry open steppe. The above correlations imply an intrinsic link between environmental change and biotic evolution. We suggest that a decrease in sea surface temperature and the westward retreat of Paratethys induced by global cooling were the key factors responsible for the enhanced aridity of the Asian inland after 14 Ma, which controlled the reduced water vapor transported by the Westerlies to the interior of Asia.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"245 ","pages":"Article 104691"},"PeriodicalIF":4.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142935474","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}
Pub Date : 2025-02-01DOI: 10.1016/j.gloplacha.2025.104692
Dandan Wang , Qinghai Xu , Yuanhao Sun , Shengrui Zhang
Understanding the variability and forcing mechanisms of the East Asian summer monsoon (EASM) precipitation on different timescales is critically important given its potentially adverse influence on ecosystems and economic development in North China. We present a pollen-based, well-dated, ∼10 yr resolution quantitative precipitation reconstruction from an alpine lake in North China, which provides a detailed picture of EASM evolution during the past ∼11,860 years. Based on ensemble empirical mode decomposition (EEMD) method and spectral analysis, we have revealed the centennial to multidecadal scales variability of EASM precipitation and its possible driving mechanisms during the Holocene. Our results suggest that the mean annual precipitation (MAP) varied greatly during the Holocene, with the maximum precipitation (520 mm) occurring during 9500–5020 cal. yr BP, which was ∼20 % higher than present. On the centennial scale, EASM precipitation exhibited ∼500 yr, ∼200 yr, ∼130 yr, and ∼105 yr cycles. The amplitude of the ∼500 yr cycle varied greatly during the Holocene, being higher in the early and late Holocene and lower in the middle Holocene, which was possibly linked to changes in ocean circulation induced by freshwater influx to the North Atlantic. On the multidecadal scale, the EASM precipitation was dominated by a 70–90 yr cycle, which may be related to the solar activity cycle and ocean-atmosphere interactions at both high and low latitudes. Weaker (stronger) solar activity, combined with stronger El Niño-Southern Oscillation (ENSO) during the warm phase of the Pacific Interdecadal Oscillation (PDO) and a negative phase of the Atlantic Multidecadal Oscillation (AMO), caused lower (higher) sea surface temperatures (SSTs) in the Indo-West Pacific Warm Pool (IWPWP) region, resulted in weaker (stronger) EASM circulation and decreased (increased) precipitation in North China. Our findings provide significant enlightenment for distinguishing the contribution of natural factors to the changes in EASM precipitation under future global warming scenarios.
{"title":"Centennial to multidecadal scales variability of East Asian summer monsoon precipitation in North China during the Holocene","authors":"Dandan Wang , Qinghai Xu , Yuanhao Sun , Shengrui Zhang","doi":"10.1016/j.gloplacha.2025.104692","DOIUrl":"10.1016/j.gloplacha.2025.104692","url":null,"abstract":"<div><div>Understanding the variability and forcing mechanisms of the East Asian summer monsoon (EASM) precipitation on different timescales is critically important given its potentially adverse influence on ecosystems and economic development in North China. We present a pollen-based, well-dated, ∼10 yr resolution quantitative precipitation reconstruction from an alpine lake in North China, which provides a detailed picture of EASM evolution during the past ∼11,860 years. Based on ensemble empirical mode decomposition (EEMD) method and spectral analysis, we have revealed the centennial to multidecadal scales variability of EASM precipitation and its possible driving mechanisms during the Holocene. Our results suggest that the mean annual precipitation (MAP) varied greatly during the Holocene, with the maximum precipitation (520 mm) occurring during 9500–5020 cal. yr BP, which was ∼20 % higher than present. On the centennial scale, EASM precipitation exhibited ∼500 yr, ∼200 yr, ∼130 yr, and ∼105 yr cycles. The amplitude of the ∼500 yr cycle varied greatly during the Holocene, being higher in the early and late Holocene and lower in the middle Holocene, which was possibly linked to changes in ocean circulation induced by freshwater influx to the North Atlantic. On the multidecadal scale, the EASM precipitation was dominated by a 70–90 yr cycle, which may be related to the solar activity cycle and ocean-atmosphere interactions at both high and low latitudes. Weaker (stronger) solar activity, combined with stronger El Niño-Southern Oscillation (ENSO) during the warm phase of the Pacific Interdecadal Oscillation (PDO) and a negative phase of the Atlantic Multidecadal Oscillation (AMO), caused lower (higher) sea surface temperatures (SSTs) in the Indo-West Pacific Warm Pool (IWPWP) region, resulted in weaker (stronger) EASM circulation and decreased (increased) precipitation in North China. Our findings provide significant enlightenment for distinguishing the contribution of natural factors to the changes in EASM precipitation under future global warming scenarios.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"245 ","pages":"Article 104692"},"PeriodicalIF":4.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142975635","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}
Pub Date : 2025-02-01DOI: 10.1016/j.gloplacha.2024.104660
Mengna Chen , Chenglong Su , Shuang Wang , Da-Wei Li , Hailong Zhang , Li Li , Guangxue Li , Bingyuan Xu , Jishang Xu , Meixun Zhao
The burial of terrestrial organic carbon (OC) in marine sediments is a crucial process in the global carbon cycle, as it transfers carbon from relatively active to inactive reservoirs. However, there remains a limited understanding of the spatial and temporal variations in the source and age characteristics of terrestrial OC in marine sediments, which determine its ability to serve as a contemporary carbon sink. In this study, radiocarbon isotope (14C, expressed as F14C) analysis was conducted on bulk OC from a sediment core (M063–05) collected from the middle Okinawa Trough, with core depositional ages spanning 1.5–16.1 ka. A novel mathematical approach was developed to differentiate the carbon isotope signals of terrestrial OC from those of bulk OC properties, enabling the investigation of the source, age, and burial flux of terrestrial OC in the Okinawa Trough. Our results indicate that sedimentary OC in the Okinawa Trough was predominantly composed of marine OC (average proportion, 58 %), with terrestrial OC present to a lesser extent (average proportion, 42 %). Terrestrial OC in core M063–05 was found to be primarily a mixture of terrestrial OC from the Huanghe (Yellow River) and petrogenic OC from Taiwan Island, and the apparent initial ages of terrestrial OC (AIRterrestrial) exhibited higher values of 7933–8886 yr during the mid-late Holocene compared to 3062–7677 yr during the marine transgression stage. The elevated AIRterrestrial during sea level highstand was attributed to (1) increased petrogenic OC input from Taiwan Island due to the intensified Kuroshio Current, which transports material from Taiwan northward along the Okinawa Trough, and (2) vigorous hydrodynamic processes in the continental shelves of the East China marginal seas, leading to significant aging of terrestrial OC during lateral transport. This innovative dual carbon isotope-based approach (enumeration method) elucidates the temporal variations in terrestrial OC sources and age characteristics in a typical continental slope within the western Pacific Ocean, providing a framework for investigating the sources and fate of terrestrial OC in marginal seas, especially in scenarios where potential changes in carbon isotope endmembers occur in response to climate and environmental changes.
{"title":"Dual carbon isotopes constrain the sources and age variations of terrestrial organic carbon in the middle Okinawa Trough since the last deglaciation","authors":"Mengna Chen , Chenglong Su , Shuang Wang , Da-Wei Li , Hailong Zhang , Li Li , Guangxue Li , Bingyuan Xu , Jishang Xu , Meixun Zhao","doi":"10.1016/j.gloplacha.2024.104660","DOIUrl":"10.1016/j.gloplacha.2024.104660","url":null,"abstract":"<div><div>The burial of terrestrial organic carbon (OC) in marine sediments is a crucial process in the global carbon cycle, as it transfers carbon from relatively active to inactive reservoirs. However, there remains a limited understanding of the spatial and temporal variations in the source and age characteristics of terrestrial OC in marine sediments, which determine its ability to serve as a contemporary carbon sink. In this study, radiocarbon isotope (<sup>14</sup>C, expressed as F<sup>14</sup>C) analysis was conducted on bulk OC from a sediment core (M063–05) collected from the middle Okinawa Trough, with core depositional ages spanning 1.5–16.1 ka. A novel mathematical approach was developed to differentiate the carbon isotope signals of terrestrial OC from those of bulk OC properties, enabling the investigation of the source, age, and burial flux of terrestrial OC in the Okinawa Trough. Our results indicate that sedimentary OC in the Okinawa Trough was predominantly composed of marine OC (average proportion, 58 %), with terrestrial OC present to a lesser extent (average proportion, 42 %). Terrestrial OC in core M063–05 was found to be primarily a mixture of terrestrial OC from the Huanghe (Yellow River) and petrogenic OC from Taiwan Island, and the apparent initial ages of terrestrial OC (AIR<sub>terrestrial</sub>) exhibited higher values of 7933–8886 yr during the mid-late Holocene compared to 3062–7677 yr during the marine transgression stage. The elevated AIR<sub>terrestrial</sub> during sea level highstand was attributed to (1) increased petrogenic OC input from Taiwan Island due to the intensified Kuroshio Current, which transports material from Taiwan northward along the Okinawa Trough, and (2) vigorous hydrodynamic processes in the continental shelves of the East China marginal seas, leading to significant aging of terrestrial OC during lateral transport. This innovative dual carbon isotope-based approach (enumeration method) elucidates the temporal variations in terrestrial OC sources and age characteristics in a typical continental slope within the western Pacific Ocean, providing a framework for investigating the sources and fate of terrestrial OC in marginal seas, especially in scenarios where potential changes in carbon isotope endmembers occur in response to climate and environmental changes.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"245 ","pages":"Article 104660"},"PeriodicalIF":4.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142797882","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}
Pub Date : 2025-02-01DOI: 10.1016/j.gloplacha.2024.104659
Vivi Vajda , Susan Nehzati , Gavin Kenny , Hermann D. Bermúdez , Ashley Krüger , Alexander Björling , Adriana Ocampo , Ying Cui , Kajsa G.V. Sigfridsson Clauss
The Chicxulub asteroid that ended the Cretaceous Era ∼66.05 million years ago caused a prolonged time of global darkness – the impact winter – leading to mass extinctions. Elements from the asteroid, including the platinum group elements (PGEs) osmium, iridium and platinum are known from the globally distributed boundary clay but their carrier elements have so far been unknown. We identify, for the first time in detail, the presence of these PGEs within Chicxulub impact spherules and importantly, we identify their carrier elements. We show through synchrotron Nano-XRF how these PGEs occur in nanostructures as un-ordered cube- and/or needle-like crystals co-localizing with both siderophile and chalcophile elements including Co, Ni, Cu, Zn, and Pb, derived from the asteroid. These crystals are set within a matrix of iron-rich calcium and silica glass revealing the mix of vaporized target rock and the asteroid. The results provide insights into the combination of elements present in the spherules, indicating formation of new minerals. We argue that the nano-shards of unreactive elements such as platinum, iridium and copper acted as nuclei for aerosol formation and potentially contributed to a prolonged impact winter with darkness and cooling leading to a profound and long-term climate change.
{"title":"Nanoparticles of iridium and other platinum group elements identified in Chicxulub asteroid impact spherules – Implications for impact winter and profound climate change","authors":"Vivi Vajda , Susan Nehzati , Gavin Kenny , Hermann D. Bermúdez , Ashley Krüger , Alexander Björling , Adriana Ocampo , Ying Cui , Kajsa G.V. Sigfridsson Clauss","doi":"10.1016/j.gloplacha.2024.104659","DOIUrl":"10.1016/j.gloplacha.2024.104659","url":null,"abstract":"<div><div>The Chicxulub asteroid that ended the Cretaceous Era ∼66.05 million years ago caused a prolonged time of global darkness – the impact winter – leading to mass extinctions. Elements from the asteroid, including the platinum group elements (PGEs) osmium, iridium and platinum are known from the globally distributed boundary clay but their carrier elements have so far been unknown. We identify, for the first time in detail, the presence of these PGEs within Chicxulub impact spherules and importantly, we identify their carrier elements. We show through synchrotron Nano-XRF how these PGEs occur in nanostructures as un-ordered cube- and/or needle-like crystals co-localizing with both siderophile and chalcophile elements including Co, Ni, Cu, Zn, and Pb, derived from the asteroid. These crystals are set within a matrix of iron-rich calcium and silica glass revealing the mix of vaporized target rock and the asteroid. The results provide insights into the combination of elements present in the spherules, indicating formation of new minerals. We argue that the nano-shards of unreactive elements such as platinum, iridium and copper acted as nuclei for aerosol formation and potentially contributed to a prolonged impact winter with darkness and cooling leading to a profound and long-term climate change.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"245 ","pages":"Article 104659"},"PeriodicalIF":4.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142797885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The simultaneous occurrence of extremes (e.g., droughts) at multiple regions (usually termed as spatial compounding of extremes), such as croplands, may lead to large impacts on global food security. Recently, the concurrent droughts and hot extremes at a specific location, which are referred to as compound droughts and hot extremes (CDHEs), have garnered considerable attention due to the potentially amplified impacts of individual extremes. Though the spatial compounding of individual droughts or hot extremes has been assessed, the variability of the spatial compounding of CDHEs across multiple croplands in China has been lacking due to relatively short records or small sample sizes. In this study, we evaluated changes in the spatial compounding of CDHEs across multiple croplands in China, including Songnen Plain (SN), North China Plain (NC), and Sichuan Basin (SC), based on precipitation and temperature data from CN05.1 and large ensemble model (CESM1-CAM5). Results show that the frequency of CDHEs in each region will increase in future periods especially for the eastern SN, central NC, and northern SC (increase by more than 15 months), with more than 70 % of the 40 ensemble members showing a large increase. Projected changes of different cases of spatial compounding of CDHEs in three croplands (i.e., SN-NC, NC-SC, SN-SC, SN-NC-SC) showed increases from 1961–2010 to 2031–2080. In particular, higher increases in the spatial compounding of CDHEs in the NC-SC region are projected (from 0.58 to 3.73 months on average), with the ratio of non-zero event members increasing from 47.5 % to 95 %. These results underscore the high risk of the spatial compounding of extremes at multiple croplands in China in the future.
{"title":"Large ensemble simulations indicate increases in spatial compounding of droughts and hot extremes across multiple croplands in China","authors":"Boying Lv, Zengchao Hao, Yutong Jiang, Qian Ma, Yitong Zhang","doi":"10.1016/j.gloplacha.2024.104670","DOIUrl":"10.1016/j.gloplacha.2024.104670","url":null,"abstract":"<div><div>The simultaneous occurrence of extremes (e.g., droughts) at multiple regions (usually termed as spatial compounding of extremes), such as croplands, may lead to large impacts on global food security. Recently, the concurrent droughts and hot extremes at a specific location, which are referred to as compound droughts and hot extremes (CDHEs), have garnered considerable attention due to the potentially amplified impacts of individual extremes. Though the spatial compounding of individual droughts or hot extremes has been assessed, the variability of the spatial compounding of CDHEs across multiple croplands in China has been lacking due to relatively short records or small sample sizes. In this study, we evaluated changes in the spatial compounding of CDHEs across multiple croplands in China, including Songnen Plain (SN), North China Plain (NC), and Sichuan Basin (SC), based on precipitation and temperature data from CN05.1 and large ensemble model (CESM1-CAM5). Results show that the frequency of CDHEs in each region will increase in future periods especially for the eastern SN, central NC, and northern SC (increase by more than 15 months), with more than 70 % of the 40 ensemble members showing a large increase. Projected changes of different cases of spatial compounding of CDHEs in three croplands (i.e., SN-NC, NC-SC, SN-SC, SN-NC-SC) showed increases from 1961–2010 to 2031–2080. In particular, higher increases in the spatial compounding of CDHEs in the NC-SC region are projected (from 0.58 to 3.73 months on average), with the ratio of non-zero event members increasing from 47.5 % to 95 %. These results underscore the high risk of the spatial compounding of extremes at multiple croplands in China in the future.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"245 ","pages":"Article 104670"},"PeriodicalIF":4.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841260","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}
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