Global and Planetary Change最新文献

{"title":"Half-day (daytime and nighttime) precipitation extremes in China: Changes and attribution from 1981 to 2022","authors":"Jiahao Han, Shibo Fang, Xiaomao Lin, Zhanhao Zhang, Man Li, Yanru Yu, Wen Zhuo, Xinyu Wang","doi":"10.1016/j.gloplacha.2025.104696","DOIUrl":"https://doi.org/10.1016/j.gloplacha.2025.104696","url":null,"abstract":"Increased atmospheric water vapor pressure due to the warming climate has led to more frequent and extreme precipitation events, which has resulted in incalculable losses. The hydrothermal circulation suggests that extreme daytime and nighttime precipitation patterns can have many distinct consequences,ranging from changes in various scale hydrological cycles to social security concerns. However, the spatio-temporal patterns of daytime and nighttime precipitation events remain underexplored, lacking quantitative analysis. Therefore, our study analyzed daily precipitation data (including 24-h, daytime, and nighttime) from 1981 to 2022 across China to investigate extreme precipitation patterns at a half-day scale (daytime and nighttime). Fourteen monthly extreme indices associated with atmospheric circulations and sea surface temperatures were examined to clarify precipitation distribution patterns using random forest and optimal fingerprinting techniques. The main findings are: (1) A clear upward trend was found in cumulative precipitation, intensifying the frequency of extreme precipitation events. Notably, the increase in both accumulated 24-h precipitation and the rate of nighttime precipitation exceeded the rate of daytime precipitation between 1981 and 2022. This trend became more pronounced as precipitation events became more extreme. (2) Most regions in China exhibited an increasing trend in both cumulative precipitation days and total precipitation, particularly in the North China Plain, although the Yunnan-Guizhou Plateau saw significant decreases in both variables. (3) Extreme precipitation events were primarily driven by changes in the different types of the Subtropical High (Western Pacific, South China Sea, and Northern Hemisphere Subtropical High), along with the typhoons southeast of the Hu Huanyong line. These findings enhance the understanding of hydrothermal exchange processes and extreme precipitation, providing a useful basis for climate change adaptations in China.","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"59 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142935463","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}

{"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":"https://doi.org/10.1016/j.gloplacha.2024.104691","url":null,"abstract":"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.","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"35 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-12-30","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}

{"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":"https://doi.org/10.1016/j.gloplacha.2024.104689","url":null,"abstract":"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.","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"60 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-12-29","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}

{"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":"https://doi.org/10.1016/j.gloplacha.2024.104690","url":null,"abstract":"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.","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"1 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-12-29","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}

{"title":"The origin of ferruginous concretions on the Sunda Shelf (SE Asia) and its environmental implications","authors":"Kaikai Wu, Xuefa Shi, Shengfa Liu, Franck Bassinot, Christophe Colin, Hui Zhang, Che Abd. Rahim Mohamed","doi":"10.1016/j.gloplacha.2024.104687","DOIUrl":"https://doi.org/10.1016/j.gloplacha.2024.104687","url":null,"abstract":"Marine concretions are an important source of information regarding resources, climate, and environment. However, the genesis of ferruginous concretions on the continental shelf remains unclear. In this study, we present the radiocarbon ages (AMS<ce:sup loc=\"post\">14</ce:sup>C), elemental compositions, and mineral compositions of ferruginous concretions obtained from a gravity core on the central Sunda Shelf. The results indicate that the formation ages of ferruginous concretions range from 10.5 to 7.5 cal ka BP from the bottom to the top of the core. The predominant mineral identified in these concretions is goethite, which cements clay and other minerals in colloidal form. Notably, Fe, Si, and Al display distinct ring-band rhythmic variations. Our study suggests that ferruginous concretions are formed in subaerial and aqueous environments, with a weathered stiff clay layer serving as the main stratum for concretion development. During periods of low sea levels (before 10.5 cal ka BP), paleo-channels likely provided fluctuating wet and dry conditions for the formation of light and dark concentric layers within ferruginous concretions. Between 10.5 and 7.5 cal ka BP, the Sunda Shelf was gradually inundated, leading to the partial transport of concretions from nearby channels. Subsequently, after 7.5 cal ka BP, the paleo-channels became completely submerged, halting the formation of ferruginous concretions on the Sunda Shelf. Meanwhile, ferruginous concretions on the seafloor became mixed with sediments and marine organisms due to hydrodynamic sorting. The presence of ferruginous concretions can serve as an indicator of paleo-channel locations, aiding in the reconstruction of paleo-channel systems during periods of low sea level on the shallow continental shelf.","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"180 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142905666","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}

{"title":"Marine productivity controlled by oceanic circulation in the Northwest Pacific over the last glacial cycle","authors":"Limin Hu, Hao Fang, Xuefa Shi, Yuying Zhang, Zhifei Duan, Chao Li, Jörg Lippold, Minoru Ikehara, Yiming Luo","doi":"10.1016/j.gloplacha.2024.104686","DOIUrl":"https://doi.org/10.1016/j.gloplacha.2024.104686","url":null,"abstract":"The oceanic carbon cycles have a significant effect on the climate transitions by influencing the atmospheric CO<ce:inf loc=\"post\">2</ce:inf> levels. As one of the largest carbon sinks, the Northwest Pacific is the key to understand how the carbon cycles react to past and future climate changes. In this study, the marine productivity in Northwest Pacific over the last 25,000 years has been comprehensively reconstructed using <ce:sup loc=\"post\">230</ce:sup>Th-normalized biogenic fluxes recorded in a series of sedimentary cores. Our results show contrasting onsets of productivity pulse between cores from the subarctic and the subtropical gyres, while both have been controlled by the nutrient supply related to ocean circulation. Specifically, the wind-driven southward shift of subarctic gyre combined with stronger East Asia winter monsoon during the Last Glacial Maximum and early deglaciation supplied more nutrients to the south and stimulated the subtropical productivity, while this process synchronously limited the subarctic productivity especially with downward extension of the North Pacific Intermediate Water (NPIW). The contraction of subarctic gyre associated with the collapse of the NPIW during the Bølling-Allerød generated the productivity pulse in subarctic region and lowered the subtropical productivity. Terrigenous inputs, reconstructed from <ce:sup loc=\"post\">232</ce:sup>Th fluxes, however, mainly affected the productivity in the subtropical gyre over the last glacial cycle, especially for the marginal region, in contrast to the pelagic subarctic gyre. Our findings reveal an interplay between subarctic and subtropical gyres and their integrated impacts on marine productivity, providing a paleoceanographic perspective to understand the carbon budget across different timescales in the Northwest Pacific.","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"23 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142905675","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}

{"title":"The Rowley Shoals atolls: Remnants of a Miocene great barrier reef on the north-west Australian margin","authors":"Jackson C. McCaffrey, Stephen J. Gallagher, Malcolm W. Wallace, Tanita Averes, Stanislaus G. Fabian, Katja Lindhorst, Lars Reuning, Sebastian Krastel","doi":"10.1016/j.gloplacha.2024.104688","DOIUrl":"https://doi.org/10.1016/j.gloplacha.2024.104688","url":null,"abstract":"The tropical North West Shelf of Australia hosts a diverse range of modern reefs. Six shelf edge isolated atolls are present north of 18°S including: Ashmore Reef, Scott Reef and Seringapatam Reef, and three Rowley Shoals. The Ningaloo Reef is a fringing reef around the North West Cape at 22°S. All of these reefs are the remnants of a vast 2000 km long barrier reef that drowned during the Late Miocene (∼10 Ma). Despite extensive hydrocarbon exploration in the region, the history of these isolated reefs is not well known. Seismic analyses combined with stratigraphic analyses of International Ocean Discovery Site U1464 near the Rowley Shoals has revealed that these modern isolated atolls have a complex evolution related to climate and tectonism as they managed to survive on their Miocene barrier reef foundation.","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"72 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142905669","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}

{"title":"Alternating dominance of Westerlies and East Asian winter monsoon on dust activities across the northeastern Qinghai-Tibet Plateau since 18.5 ka","authors":"Hao Long, Yun Cai, Jingran Zhang, Liangqing Cheng, Linhai Yang, Hongyi Cheng","doi":"10.1016/j.gloplacha.2024.104684","DOIUrl":"https://doi.org/10.1016/j.gloplacha.2024.104684","url":null,"abstract":"The mid-latitude Westerlies and the East Asian winter monsoon (EAWM) are two major atmospheric circulation systems influencing dust activities in the Northern Hemisphere (NH). However, the interplay between these wind systems and their effects on regional dust activities remain poorly understood. In this study, we present a well-dated aeolian sedimentary sequence from the loess section (ZES) on the southern slope of the Qilian Mountains in the northeastern Qinghai-Tibetan Plateau (NE-QTP). It provides insights into the response of dust activities to these wind systems for the last 18.5 ka. We developed a detailed chronology for ZES section based on luminescence dating of multiple signals from 29 samples (yielding a total of 87 ages). The luminescence sensitivities and element analysis of the sediments indicate a shift in dust source around 7.5 ka, contributed to a transition in the atmospheric circulation controls of the NE-QTP. Specially, our findings suggest that dust activity was likely dominated by EAWM from 18.5 ka to 7.5 ka and by the Westerlies after 7.5 ka across this area. We propose that increased NH ice volume (NHIV) significantly enhanced the EAWM via strengthening Siberian High, driving dust activities over the high mountains during the Last Deglaciation and Early Holocene. In contrast, as NHIV decreased during the middle-to-late Holocene, the EAWM weakened and retreated from this area, allowing the Westerlies to dominate dust activities. Additionally, grain-size parameters of sediments were used to infer variations in the intensities of these winds, revealing a gradual weakening of EAWM since the Last Deglaciation and a marked intensification of the Westerlies during the warm middle Holocene. Under the current global warming scenario, we predict that the Westerlies will continue to dominate dust activities across the NE-QTP, with a potential increase in dust activities if the Westerlies enhance.","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"11 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142884634","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}

{"title":"From holocene to anthropogenic impact: Surpassing coral's pH up-regulation capacity under ocean acidification","authors":"Huiling Kang, Xuefei Chen, Guangchao Deng, Jian-xin Zhao, Gangjian Wei","doi":"10.1016/j.gloplacha.2024.104683","DOIUrl":"https://doi.org/10.1016/j.gloplacha.2024.104683","url":null,"abstract":"Corals' regulation of internal calcifying fluid (CF or cf) chemistry is crucial for their extraordinary calcification capacity, endowing them with a certain ability to cope with environmental changes such as anthropogenic ocean acidification (OA) and warming. However, it remains unclear whether the impacts of these changes on corals have substantially surpassed their regulation capacity, particularly in comparison to the CF chemistry responses to natural climate variability with minor or no human perturbation. In this study, we reconstructed the pH, dissolved inorganic carbon, and carbonate ion concentrations in coral CF (pH<ce:inf loc=\"post\">cf</ce:inf>, DIC<ce:inf loc=\"post\">cf</ce:inf>, and [CO<ce:inf loc=\"post\">3</ce:inf><ce:sup loc=\"post\">2−</ce:sup>]<ce:inf loc=\"post\">cf</ce:inf>) during the Mid- to Late-Holocene, by analyzing the skeletal δ<ce:sup loc=\"post\">11</ce:sup>B and B/Ca of 80 <ce:italic>Porites</ce:italic> spp. from eastern Hainan Island in the South China Sea (SCS). Our records indicate considerable inter-colony variations in CF chemistry, with maximum disparities reaching 0.18 units for pH<ce:inf loc=\"post\">cf</ce:inf> and 1664 μmol/kg for DIC<ce:inf loc=\"post\">cf</ce:inf>. With this in mind, we found no clear responses of coral DIC<ce:inf loc=\"post\">cf</ce:inf> to the climate fluctuations during the past ∼5500 years, nor evident differences in pH<ce:inf loc=\"post\">cf</ce:inf> and [CO<ce:inf loc=\"post\">3</ce:inf><ce:sup loc=\"post\">2−</ce:sup>]<ce:inf loc=\"post\">cf</ce:inf> across pre-industrial natural epochs. However, pH<ce:inf loc=\"post\">cf</ce:inf> and [CO<ce:inf loc=\"post\">3</ce:inf><ce:sup loc=\"post\">2−</ce:sup>]<ce:inf loc=\"post\">cf</ce:inf> of modern corals have significantly declined compared to fossil corals. Further analyzes compiling global data on <ce:italic>Porites</ce:italic> spp. also confirm this pronounced pH<ce:inf loc=\"post\">cf</ce:inf> decrease in modern corals, suggesting the limitations of pantropical corals to counteract OA by up-regulating pH<ce:inf loc=\"post\">cf</ce:inf>. Importantly, these fossil and modern corals reveal a clear long-term pH<ce:inf loc=\"post\">cf</ce:inf> descending trend parallel to atmospheric CO<ce:inf loc=\"post\">2</ce:inf> changes, supporting the reliability of coral δ<ce:sup loc=\"post\">11</ce:sup>B in recording long-term changes in seawater pH (pH<ce:inf loc=\"post\">sw</ce:inf>).","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"3 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142905670","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}

{"title":"Nitrogen cycling and marine redox evolution during the Ediacaran–Cambrian transition","authors":"Chao Chang, Thomas J. Algeo","doi":"10.1016/j.gloplacha.2024.104679","DOIUrl":"https://doi.org/10.1016/j.gloplacha.2024.104679","url":null,"abstract":"The Cambrian Explosion was an unprecedented bioevolutionary event that witnessed rapid diversification of marine invertebrate phyla and establishment of metazoan-dominated marine ecosystems. Nitrogen is a critical nutrient element essential for all life on Earth, and its biogeochemical cycling in the ocean is tightly associated with marine redox conditions. Numerous nitrogen isotope investigations of the Ediacaran-Cambrian (<ce:italic>E</ce:italic>-C) transition have been undertaken, but an integrated analysis of contemporaneous nitrogen cycling has not been achieved yet. Here, we compile published nitrogen isotope data for the South China Craton over the interval from ∼550 Ma (late Ediacaran) to ∼514 Ma (late Stage 3 of early Cambrian) with the goals of identifying key changes in the nitrogen cycle and their relationship to marine redox evolution and the Cambrian Explosion. Combined with independent redox proxy data, our δ<ce:sup loc=\"post\">15</ce:sup>N dataset provides insights into spatio-temporal variation in rates of denitrification and N<ce:inf loc=\"post\">2</ce:inf> fixation induced by marine redox fluctuations, which constrains the distribution of suboxic environments and the relative position of the oceanic redoxcline. On this basis, we propose a new model of marine nitrogen-cycle evolution during the E–C transition in which (1) nitrate availability modulated the ecological development and distribution of eukaryotic primary producers, and (2) nitrate-replete ecological niches for eukaryotic primary producers, especially benthic algae expanded significantly during Cambrian Age 3, and (3) increasing biological pump efficiency promoted organic burial and net O<ce:inf loc=\"post\">2</ce:inf> release, thus contributing to oceanic oxygenation and the radiation of early animals.","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"25 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142884637","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}