The chemical weathering of basalt rocks is crucial for stabilizing Earth's habitability and carbon cycle. Currently, the soil chemistry and weathering rates of basalt under significant aeolian influence are not fully understood. This study addresses this gap by investigating the U geochemistry and regolith production rates in a highly weathered basalt profile in Southern China. The εNd(0) values decrease from the bedrock sample (4.68) to the top soils (0.94), indicating aerosol input from the top. Dust accretion decrease downward and significantly affects the vertical distribution of U (R2 = 0.86), while the chemical mobilization of U is controlled by binding with Fe oxides-organic matter complexes (R2 = 0.33).
{"title":"U-series isotope constraints on the rates of aeolian-impacted basaltic weathering under tropical climate","authors":"Guodong Ming, Jingyi Huang, Jiaru Sheng, Yingzeng Gong, Jiye Guo, Huimin Yu, Wenhan Cheng, Craig C. Lundstrom, Fang Huang","doi":"10.1016/j.gloplacha.2024.104673","DOIUrl":"https://doi.org/10.1016/j.gloplacha.2024.104673","url":null,"abstract":"The chemical weathering of basalt rocks is crucial for stabilizing Earth's habitability and carbon cycle. Currently, the soil chemistry and weathering rates of basalt under significant aeolian influence are not fully understood. This study addresses this gap by investigating the U geochemistry and regolith production rates in a highly weathered basalt profile in Southern China. The ε<ce:inf loc=\"post\">Nd(0)</ce:inf> values decrease from the bedrock sample (4.68) to the top soils (0.94), indicating aerosol input from the top. Dust accretion decrease downward and significantly affects the vertical distribution of U (R<ce:sup loc=\"post\">2</ce:sup> = 0.86), while the chemical mobilization of U is controlled by binding with Fe oxides-organic matter complexes (R<ce:sup loc=\"post\">2</ce:sup> = 0.33).","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"54 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142884685","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}
Rapid climate change is reshaping the ecological dynamics of coral reefs, posing significant challenges in understanding the long-term effects of environmental disturbances on reef development. In the current study, we conducted a chronological analysis and regional review of Holocene massive Porites corals in the northern South China Sea, revealing a unique episodic growth pattern, including a 2500-year growth hiatus. The findings suggest that this collapse was driven by the coupling of intensified East Asian winter monsoon and broader-scale El Niño–Southern Oscillation variability. Regional environmental drivers significantly influenced spatiotemporal variations in coral growth stagnation across the Pan-Pacific region. While future sea level rise and warming may benefit nearshore corals, the projected intensification of El Niño–Southern Oscillation variability could undermine the potential of the northern South China Sea as a coral refuge. Effective coral management and environmental mitigation measures are crucial to preventing further collapse of regional coral reefs.
{"title":"Triggering of a 2500-year coral shutdown in northern South China Sea by coupled East Asian Monsoon and El Niño–Southern Oscillation","authors":"Fei Tan, Yunfeng Zhang, Guowei Fu, Qi Shi, Xiyang Zhang, Shengnan Zhou, Mingzhuang Wang, Guotao Zhang, Xiaoju Liu, Jian-xin Zhao, Hongqiang Yang","doi":"10.1016/j.gloplacha.2024.104672","DOIUrl":"https://doi.org/10.1016/j.gloplacha.2024.104672","url":null,"abstract":"Rapid climate change is reshaping the ecological dynamics of coral reefs, posing significant challenges in understanding the long-term effects of environmental disturbances on reef development. In the current study, we conducted a chronological analysis and regional review of Holocene massive <ce:italic>Porites</ce:italic> corals in the northern South China Sea, revealing a unique episodic growth pattern, including a 2500-year growth hiatus. The findings suggest that this collapse was driven by the coupling of intensified East Asian winter monsoon and broader-scale El Niño–Southern Oscillation variability. Regional environmental drivers significantly influenced spatiotemporal variations in coral growth stagnation across the Pan-Pacific region. While future sea level rise and warming may benefit nearshore corals, the projected intensification of El Niño–Southern Oscillation variability could undermine the potential of the northern South China Sea as a coral refuge. Effective coral management and environmental mitigation measures are crucial to preventing further collapse of regional coral reefs.","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"82 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841261","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 : 2024-12-09DOI: 10.1016/j.gloplacha.2024.104676
Yi Zhong, Yuxing Liu, Xiaojing Du, Xiaoxu Shi, Xing Xu, Zhengyao Lu, Stefanie Kaboth-Bahr, Mark J. Dekkers, Juan C. Larrasoaña, Keiji Horikawa, Chijun Sun, Liang Ning, André Bahr, Yanan Zhang, Debo Zhao, Jiabo Liu, Wenyue Xia, Jingyu Zhang, Sheng Yang, Hai Li, Xiaoyue Liang, Chenxi Hong, Zhengyang Dai, Yuanjie Li, Qingsong Liu
The millennial-scale hydroclimate variability in East Asia has been debated for a long time due to the lack of reliable precipitation records from southern China and inconsistent model simulations. Here, we reconstruct a 40-kyr rainfall record for southern China and Taiwan based on enviro-magnetic and clay mineral proxy parameters from a northern South China Sea marine sediment core. Both proxies suggest reduced East Asian Summer Monsoon (EASM) precipitation in the southern China-Taiwan region during North Atlantic cooling episodes. After integration with other EASM precipitation records and modeling results, we conclude that the spatial precipitation pattern across Southeast Asia is closely related to the strength of the Pacific Walker Circulation. This interpretation is supported by a model simulation that emphasizes the role of the Walker Circulation in transferring North Atlantic climate variability to the East Asian hydroclimate. Our findings contribute to resolving the disparities between precipitation proxies and model simulations in Southeast Asia.
{"title":"Pacific Walker Circulation modulated millennial-scale East Asian summer monsoon rainfall variability over the past 40 kyr","authors":"Yi Zhong, Yuxing Liu, Xiaojing Du, Xiaoxu Shi, Xing Xu, Zhengyao Lu, Stefanie Kaboth-Bahr, Mark J. Dekkers, Juan C. Larrasoaña, Keiji Horikawa, Chijun Sun, Liang Ning, André Bahr, Yanan Zhang, Debo Zhao, Jiabo Liu, Wenyue Xia, Jingyu Zhang, Sheng Yang, Hai Li, Xiaoyue Liang, Chenxi Hong, Zhengyang Dai, Yuanjie Li, Qingsong Liu","doi":"10.1016/j.gloplacha.2024.104676","DOIUrl":"https://doi.org/10.1016/j.gloplacha.2024.104676","url":null,"abstract":"The millennial-scale hydroclimate variability in East Asia has been debated for a long time due to the lack of reliable precipitation records from southern China and inconsistent model simulations. Here, we reconstruct a 40-kyr rainfall record for southern China and Taiwan based on enviro-magnetic and clay mineral proxy parameters from a northern South China Sea marine sediment core. Both proxies suggest reduced East Asian Summer Monsoon (EASM) precipitation in the southern China-Taiwan region during North Atlantic cooling episodes. After integration with other EASM precipitation records and modeling results, we conclude that the spatial precipitation pattern across Southeast Asia is closely related to the strength of the Pacific Walker Circulation. This interpretation is supported by a model simulation that emphasizes the role of the Walker Circulation in transferring North Atlantic climate variability to the East Asian hydroclimate. Our findings contribute to resolving the disparities between precipitation proxies and model simulations in Southeast Asia.","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"48 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841258","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 : 2024-12-09DOI: 10.1016/j.gloplacha.2024.104674
Carlie Mentzer, Carmala Garzione, Carlos Jaramillo, Luis Felipe Hinojosa, Jaime Escobar, Nataly Glade, Sebastian Gomez, Deepshikha Upadhyay, Aradhna Tripati, Kaustubh Thirumalai
The Miocene-Pliocene boundary (∼5.3 million years ago, Ma) represents a climate transition, where global warming resulted in a rise in sea surface temperatures from near modern values in the late Miocene, to sustained, warmer than modern values in the early Pliocene. Estimated atmospheric CO2 concentrations were within the range of anthropogenic values. Thus, this transition provides an opportunity to evaluate hydroclimate responses to warming, when the Earth system was in equilibrium with near modern atmospheric CO2 levels. Here, we utilize lacustrine carbonate stable and clumped isotope methods, and palynology, to investigate hydroclimate trends within the western Altiplano of Chile during the late Miocene and early Pliocene. The results provide observational support for a warmer and wetter-than-modern climate over these timeframes. However, increasing aridity across the Miocene-Pliocene boundary suggests a hydroclimate response to global climate forcing. Given the sensitivity of the region's climate to disturbances in tropical Pacific, ocean-atmospheric processes, we speculate that this aridification may reflect progressive weakening of the Pacific Walker Circulation, in response to global warming.
{"title":"Late Miocene-early Pliocene hydroclimate evolution of the western Altiplano, northern Chile: Implications for aridification trends under warming climate conditions","authors":"Carlie Mentzer, Carmala Garzione, Carlos Jaramillo, Luis Felipe Hinojosa, Jaime Escobar, Nataly Glade, Sebastian Gomez, Deepshikha Upadhyay, Aradhna Tripati, Kaustubh Thirumalai","doi":"10.1016/j.gloplacha.2024.104674","DOIUrl":"https://doi.org/10.1016/j.gloplacha.2024.104674","url":null,"abstract":"The Miocene-Pliocene boundary (∼5.3 million years ago, Ma) represents a climate transition, where global warming resulted in a rise in sea surface temperatures from near modern values in the late Miocene, to sustained, warmer than modern values in the early Pliocene. Estimated atmospheric CO<ce:inf loc=\"post\">2</ce:inf> concentrations were within the range of anthropogenic values. Thus, this transition provides an opportunity to evaluate hydroclimate responses to warming, when the Earth system was in equilibrium with near modern atmospheric CO<ce:inf loc=\"post\">2</ce:inf> levels. Here, we utilize lacustrine carbonate stable and clumped isotope methods, and palynology, to investigate hydroclimate trends within the western Altiplano of Chile during the late Miocene and early Pliocene. The results provide observational support for a warmer and wetter-than-modern climate over these timeframes. However, increasing aridity across the Miocene-Pliocene boundary suggests a hydroclimate response to global climate forcing. Given the sensitivity of the region's climate to disturbances in tropical Pacific, ocean-atmospheric processes, we speculate that this aridification may reflect progressive weakening of the Pacific Walker Circulation, in response to global warming.","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"70 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841207","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}
The terrigenous sediment source-to-sink processes in marginal seas are governed by intricate interactions among climate, sea level, and ocean currents. The continental slope of the northern South China Sea (SCS) provides an excellent setting to examine these processes due to its substantial terrigenous influx and continuous sedimentation. In this study, we present a high-resolution sedimentary record from the northern SCS continental slope covering the last deglaciation. Analyses of Rare Earth Elements (REEs) and Sr–Nd isotopic compositions in the NH07 core indicate that the predominant source of terrigenous sediment was Taiwan. Grain size-standard deviation analysis identified two sensitive grain size components, with the sensitive component 2 used as a marker of the Kuroshio intrusion into the northern SCS through Luzon Strait. The intensity of the Kuroshio intrusion into the northern SCS was found to be inversely related to that of the open Pacific. The Asian monsoon and El Niño-Southern Oscillation (ENSO) significantly influenced the variability of the Kuroshio Current throughout the deglaciation period. During the interval 16, 000–11, 700 cal yr BP, variations in terrigenous influx were collectively driven by sea level changes and the intensity of the Kuroshio intrusion, while chemical weathering intensity was affected by the reworking of previously exposed shelf sediments due to sea level fluctuations. During the Holocene, however, the East Asian summer monsoon intensity became the primary factor influencing variations in terrigenous influx and chemical weathering.
{"title":"Sedimentary responses to climatic variations and Kuroshio intrusion into the northern South China Sea since the last deglaciation","authors":"Chao Huang, Liyuan Wu, Jiansen Cheng, Xiaoxu Qu, Yongyi Luo, Huiling Zhang, Feng Ye, Gangjian Wei","doi":"10.1016/j.gloplacha.2024.104671","DOIUrl":"https://doi.org/10.1016/j.gloplacha.2024.104671","url":null,"abstract":"The terrigenous sediment source-to-sink processes in marginal seas are governed by intricate interactions among climate, sea level, and ocean currents. The continental slope of the northern South China Sea (SCS) provides an excellent setting to examine these processes due to its substantial terrigenous influx and continuous sedimentation. In this study, we present a high-resolution sedimentary record from the northern SCS continental slope covering the last deglaciation. Analyses of Rare Earth Elements (REEs) and Sr–Nd isotopic compositions in the NH07 core indicate that the predominant source of terrigenous sediment was Taiwan. Grain size-standard deviation analysis identified two sensitive grain size components, with the sensitive component 2 used as a marker of the Kuroshio intrusion into the northern SCS through Luzon Strait. The intensity of the Kuroshio intrusion into the northern SCS was found to be inversely related to that of the open Pacific. The Asian monsoon and El Niño-Southern Oscillation (ENSO) significantly influenced the variability of the Kuroshio Current throughout the deglaciation period. During the interval 16, 000–11, 700 cal yr BP, variations in terrigenous influx were collectively driven by sea level changes and the intensity of the Kuroshio intrusion, while chemical weathering intensity was affected by the reworking of previously exposed shelf sediments due to sea level fluctuations. During the Holocene, however, the East Asian summer monsoon intensity became the primary factor influencing variations in terrigenous influx and chemical weathering.","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"78 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841259","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 : 2024-12-06DOI: 10.1016/j.gloplacha.2024.104668
Zheng Gong, Iona Baillie, Lyle L. Nelson, Stacey H. Gerasimov, Catherine Rose, Emily F. Smith
The Nama Group in southern Namibia captures one of the best-preserved records of the last ∼10 million years of the Ediacaran Period, recording pivotal changes to Earth's biosphere and oceans. Within the Nama Group, the lower Schwarzrand Subgroup preserves early complex bilaterian trace fossils, but uncertainties surrounding the ages of their first occurrences hinder global correlation and the understanding of the rates at which critical biological changes occurred. This study presents magnetic susceptibility cyclostratigraphy of a recently acquired drill core that covers the Nudaus Formation and Nasep Member within the lower Schwarzrand Subgroup. Spectral analysis reveals a hierarchy of orbital cycles that could be responsible for the repeating depositional sequences at various length scales in the Schwarzrand Subgroup. Matching the wavelengths of the orbital cycles to their expected periodicities, we established sedimentation rates throughout the stratigraphy. Utilizing available UPb ages from correlative outcrop sections and the sedimentation rates from cyclostratigraphy, we refine the age-depth model for the lower Schwarzrand Subgroup. Our new age-depth model places tighter temporal constraints on the first appearances of complex trace fossils, thus constraining the earliest major radiation of bilaterian metazoans and contributing to a better-calibrated chronostratigraphy of the terminal Ediacaran Period.
{"title":"Magnetic susceptibility cyclostratigraphy of the lower Schwarzrand Subgroup in southern Namibia refines temporal calibration of late Ediacaran bilaterian radiation","authors":"Zheng Gong, Iona Baillie, Lyle L. Nelson, Stacey H. Gerasimov, Catherine Rose, Emily F. Smith","doi":"10.1016/j.gloplacha.2024.104668","DOIUrl":"https://doi.org/10.1016/j.gloplacha.2024.104668","url":null,"abstract":"The Nama Group in southern Namibia captures one of the best-preserved records of the last ∼10 million years of the Ediacaran Period, recording pivotal changes to Earth's biosphere and oceans. Within the Nama Group, the lower Schwarzrand Subgroup preserves early complex bilaterian trace fossils, but uncertainties surrounding the ages of their first occurrences hinder global correlation and the understanding of the rates at which critical biological changes occurred. This study presents magnetic susceptibility cyclostratigraphy of a recently acquired drill core that covers the Nudaus Formation and Nasep Member within the lower Schwarzrand Subgroup. Spectral analysis reveals a hierarchy of orbital cycles that could be responsible for the repeating depositional sequences at various length scales in the Schwarzrand Subgroup. Matching the wavelengths of the orbital cycles to their expected periodicities, we established sedimentation rates throughout the stratigraphy. Utilizing available U<ce:glyph name=\"sbnd\"></ce:glyph>Pb ages from correlative outcrop sections and the sedimentation rates from cyclostratigraphy, we refine the age-depth model for the lower Schwarzrand Subgroup. Our new age-depth model places tighter temporal constraints on the first appearances of complex trace fossils, thus constraining the earliest major radiation of bilaterian metazoans and contributing to a better-calibrated chronostratigraphy of the terminal Ediacaran Period.","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"7 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142797879","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 : 2024-12-04DOI: 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":"https://doi.org/10.1016/j.gloplacha.2024.104669","url":null,"abstract":"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.","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"41 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-12-04","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}
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":"https://doi.org/10.1016/j.gloplacha.2024.104670","url":null,"abstract":"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.","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"256 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-12-04","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}
Inland Asia is a major global source of dust and the dust transport from this region has global implications. However, the processes and forcing mechanisms of dust activity in inland Asia during the Holocene are still debated due to the lack of high-quality records with accurate dating, unambiguous dust signals, and a high resolution. Here we present a well-dated record of dust activity based on the Ti content of the sediments of Shuanghu Lake, in the southern Altai Mountains, with a ∼ 15-yr-resolution and covering the entire Holocene. This record shows a gradual decrease in dust intensity during ∼11.7–6 thousand years ago (ka), followed by a persistent increase since ∼6 ka. Frequent dust events are also evident, lasting hundreds of years, and are superimposed on the millennial-scale trend, corresponding to the nine North Atlantic Bond events. We propose that the millennial-scale trend of dust activity was primarily influenced by variations in the mid-latitude Westerlies, while the dust events on the centennial scale were driven primarily by a strengthened East Asian winter monsoon. Overall, this study provides a reliable, high-resolution record of Holocene dust activity in inland Asia, and it updates the previous view that dust activity in this region was solely controlled by the mid-latitude Westerlies or the Siberian High. Our findings contribute to an improved understanding of global dust transport with implications for predicting future dust activity in this region.
{"title":"Holocene dust activity in inland Asia driven by both the mid-latitude Westerlies and the East Asian winter monsoon","authors":"Haipeng Wang, Jianhui Chen, Yuanhao Sun, Ruijin Chen, Nasetay Aydenbek, Jianbao Liu","doi":"10.1016/j.gloplacha.2024.104661","DOIUrl":"https://doi.org/10.1016/j.gloplacha.2024.104661","url":null,"abstract":"Inland Asia is a major global source of dust and the dust transport from this region has global implications. However, the processes and forcing mechanisms of dust activity in inland Asia during the Holocene are still debated due to the lack of high-quality records with accurate dating, unambiguous dust signals, and a high resolution. Here we present a well-dated record of dust activity based on the Ti content of the sediments of Shuanghu Lake, in the southern Altai Mountains, with a ∼ 15-yr-resolution and covering the entire Holocene. This record shows a gradual decrease in dust intensity during ∼11.7–6 thousand years ago (ka), followed by a persistent increase since ∼6 ka. Frequent dust events are also evident, lasting hundreds of years, and are superimposed on the millennial-scale trend, corresponding to the nine North Atlantic Bond events. We propose that the millennial-scale trend of dust activity was primarily influenced by variations in the mid-latitude Westerlies, while the dust events on the centennial scale were driven primarily by a strengthened East Asian winter monsoon. Overall, this study provides a reliable, high-resolution record of Holocene dust activity in inland Asia, and it updates the previous view that dust activity in this region was solely controlled by the mid-latitude Westerlies or the Siberian High. Our findings contribute to an improved understanding of global dust transport with implications for predicting future dust activity in this region.","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"12 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142797881","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 : 2024-11-29DOI: 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.
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