Global and Planetary Change最新文献

{"title":"Consistency and environmental variability in mineral–organic interactions: The role of illite in organic carbon preservation in the northern South China Sea","authors":"Zhen Huang ,&nbsp;Chenyang Wang ,&nbsp;Zhaojie Yu ,&nbsp;Hongbao Qu ,&nbsp;Zhenzhen Zheng ,&nbsp;Li-Wei Zheng ,&nbsp;Shuh-Ji Kao","doi":"10.1016/j.gloplacha.2025.104983","DOIUrl":"10.1016/j.gloplacha.2025.104983","url":null,"abstract":"<div><div>Mineral–organic matter interactions are globally recognized as a primary control on the long-term preservation of sedimentary organic carbon (OC). By integrating new ramped pyrolysis/oxidation (RPO) data from the northern South China Sea (SCS) with datasets from global fjords, estuaries, and marine systems, we confirm a consistent inverse relationship between OC content and both mean activation energy (μ_E) and bond diversity (σ_E), reinforcing the thermodynamic signature of mineral-associated OC preservation. However, SCS sediments reveal a key deviation: σ_E in the SCS positively correlates with low-E OC fractions, in contrast to global patterns, suggesting that mineral interactions in this setting preferentially stabilize thermally labile components. We further show that illite, the dominant clay mineral in the SCS, correlates with broader σ_E and lower μ_E, consistent with its role in retaining OC across a thermally diverse spectrum. While smectite is often cited as more protective, it is scarce in this region and shows no significant correlation with RPO parameters. Spatial trends also highlight the importance of OC source: a unique terrestrial-influenced site (BC15) exhibits elevated thermal stability and low low-E OC fractions, likely due to the intrinsic recalcitrance of vascular plant-derived material rather than mineral protection. Our findings demonstrate that while mineral–OC interactions are globally consistent in their role, their expression is modulated by sediment mineralogy, OC sources, and depositional settings. This underscores the importance of combining thermal reactivity metrics with mineralogical context to resolve the mechanisms underpinning OC preservation.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"253 ","pages":"Article 104983"},"PeriodicalIF":4.0,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144661980","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":"Monsoon variability and high latitude climate signals in the Central Mediterranean at the Pliocene- Pleistocene transition: The Gelasian stratotype section (Monte San Nicola, Sicily) [Global and Planetary Change, volume 249, 104788]: Comment","authors":"Elena Zanola ,&nbsp;Sergio Bonomo ,&nbsp;Alessandro Incarbona ,&nbsp;Telemaco Tesei ,&nbsp;Agata Di Stefano ,&nbsp;Patrizia Ferretti ,&nbsp;Eliana Fornaciari ,&nbsp;Simone Galeotti ,&nbsp;Patrizia Macrì ,&nbsp;Isabella Raffi ,&nbsp;Teresa Rodrigues ,&nbsp;Fabio Speranza ,&nbsp;Enrico Di Stefano ,&nbsp;Rodolfo Sprovieri ,&nbsp;Domenico Rio ,&nbsp;Luca Capraro","doi":"10.1016/j.gloplacha.2025.104977","DOIUrl":"10.1016/j.gloplacha.2025.104977","url":null,"abstract":"<div><div>The stratigraphic record of Monte San Nicola (southern Sicily, Italy), where the Global Boundary Stratotype Section and Point (GSSP) for the Gelasian Stage (Lower Pleistocene) has been defined, has been studied by our research group for fifteen years. In 2021, another working group (GELSTRAT) started investigating the Monte San Nicola stratigraphy in a location close to the GSSP section, with results that differ significantly from those published by our team. In particular, major discrepancies in the alkenone-derived paleotemperature reconstructions led the GELSTRAT team to suggest that our age model is invalid, and they inferred that we had made a wrong interpretation of the physical stratigraphic record. In this comment, we demonstrate that our chronological model is correct, while the stratigraphic profile studied by the GELSTRAT team should be approached with care, due to the presence of tectonic displacements, truncations, and uncertain lithological evidence for critical marker beds, such as the sapropel layers below the Nicola bed.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"253 ","pages":"Article 104977"},"PeriodicalIF":4.0,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144655010","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":"Re-evaluation of the spatiotemporal patterns of Holocene precipitation in China","authors":"Zunyu Hu ,&nbsp;Haowen Fan ,&nbsp;Xin Dai ,&nbsp;Yuhui Liu ,&nbsp;Chaoyong Hu","doi":"10.1016/j.gloplacha.2025.104974","DOIUrl":"10.1016/j.gloplacha.2025.104974","url":null,"abstract":"<div><div>Investigating the spatiotemporal variability of past precipitation in China is essential for understanding the East Asian monsoon (EAM) dynamics. However, insufficient records of Holocene palaeo-precipitation with precise chronological constraints impedes the exploration of precipitation patterns in China, and obscures the holistic understanding of EAM evolution. In this study, we reconstruct Holocene precipitation variations across eastern China since the Holocene, using the precipitation index (PRI) derived from high-quality stalagmite δ¹⁸O records from 25 caves. Validation against other independent hydroclimatic records confirm the robustness of the PRI reconstructions. Integrating the reconstructed PRI and other proxy-based precipitation records, we systematically characterize the spatiotemporal patterns of Holocene precipitation in China. The results demonstrate a meridional and zonal time-transgressive pattern of the Holocene Optimum (HO) throughout China, initiating earliest occurrence in southwestern and northwestern China (9–8 ka BP), followed by central and northern China (7–6 ka BP), and culminating latest occurrence in southeastern and northeastern China (∼ 2 ka BP). Spatial correlation analysis reveals statistically significant relationships between the timing of HO and latitude/longitude. The TraCE-21 ka simulations exhibit congruent temporal-spatial patterns, thereby independently validating our reconstructions. We propose that the shift of the westerly jet stream modulated by Northern Hemisphere summer insolation and the movement of the Western Pacific Subtropical High constrained by the sea surface temperature across the tropical Indian Ocean-West Pacific Ocean jointly governed the spatiotemporal distribution of Holocene precipitation in China.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"253 ","pages":"Article 104974"},"PeriodicalIF":4.0,"publicationDate":"2025-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144613360","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":"Editorial preface to special issue: Life and environments in transition: The Neoproterozoic-early Paleozoic world","authors":"Meng Cheng ,&nbsp;Eva E. Stüeken ,&nbsp;Zongjun Yin ,&nbsp;Thomas J. Algeo ,&nbsp;Chao Li","doi":"10.1016/j.gloplacha.2025.104980","DOIUrl":"10.1016/j.gloplacha.2025.104980","url":null,"abstract":"<div><div>This Virtual Special Issue (VSI) presents insights from the Proterozoic-early Paleozoic world, a critical interval for the co-evolution of life and environments in Earth's history. The 16 papers in this VSI are broadly organized into three themes. The first theme presents new fossil discoveries within a refined geochronological framework, revealing limited biotic competition and a strong palaeoenvironmental control on the spatial distribution of life in the Ediacaran ocean. The second theme focuses on paleoenvironmental reconstruction. The results point to a complex, non-linear evolution of marine redox conditions, carbon cycling and continental weathering, challenging the idea of a simple environmental control on biological evolution. The third theme highlights the key role of oceanic redox conditions in the formation of phosphorus and manganese ores. Together, these studies suggest that understanding the co-evolution of life and environments during the Neoproterozoic-early Paleozoic requires a geosystems perspective incorporating a combination of interconnected tectonic, climatic, oceanic, ecological, and bioevolutionary drivers.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"253 ","pages":"Article 104980"},"PeriodicalIF":4.0,"publicationDate":"2025-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144613361","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":"Signal decomposition techniques for foF2 long-term ionospheric trend analysis","authors":"Bruno S. Zossi ,&nbsp;Franco D. Medina ,&nbsp;Trinidad Duran ,&nbsp;María A. Vega Caro ,&nbsp;Blas F. de Haro Barbas ,&nbsp;Ana G. Elias","doi":"10.1016/j.gloplacha.2025.104979","DOIUrl":"10.1016/j.gloplacha.2025.104979","url":null,"abstract":"<div><div>Four signal decomposition techniques were applied to the problem of estimating ionospheric long-term trends: a variant of Empirical Mode Decomposition (EMD), Seasonal and Trend decomposition using Loess (STL), Singular Spectrum Analysis (SSA), and Fourier Transform (FT). This is the first time these techniques have been used to estimate ionospheric trends. The results were compared with the classic double-step linear regression method, the most used method to filter the solar influence from the ionospheric foF2, and with atmospheric general circulation models. Since yearly average ionospheric data exhibit strong linear correlation with solar EUV proxies, we analyze five solar flux indices at radio wavelengths alongside ionospheric data from 9 stations covering the period 1976–2022. The decomposition models can be used independently on every time series to filter periodicities and trends. The proxies are scaled to ionospheric data range using a linear regression, and the residuals are subtracted in order to estimate trends. The results using solar flux F15 are in good agreement with trends predicted by atmospheric circulation models of 0.7 %/decade, STL and SSA result in −0.8 %/decade, and FT in −0.5 %/decade; most models and proxies result in a negative averaged trend. F10.7 trends are lower than expected, about −0.2 %/decade for SSA and STL, and − 0.1 %/decade using FT. Among the tested methods, the FT provides the most consistent results. CEEMDAN can also estimate reliable results, but only when solar and ionospheric data are filtered in the same number of steps. This work demonstrates how novel techniques can complement the study of long-term trends in the upper atmosphere. While recent studies have identified the F30 solar flux as the most suitable proxy for trend estimation, our analysis reveals that it consistently produces stronger negative trends than expected. In contrast, the F15 solar flux, an index that is rarely used, emerges as the most reliable proxy using the methodology presented in this work.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"253 ","pages":"Article 104979"},"PeriodicalIF":4.0,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144611625","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":"Transient modeling for ocean redox conditions during the mid-cretaceous Oceanic Anoxic Event 2","authors":"Qi Cui ,&nbsp;Jian Zhang ,&nbsp;Yongyun Hu ,&nbsp;Sascha Flögel ,&nbsp;Huifang Guo ,&nbsp;Yihui Chen","doi":"10.1016/j.gloplacha.2025.104976","DOIUrl":"10.1016/j.gloplacha.2025.104976","url":null,"abstract":"<div><div>Reconstructions of the mid-Cretaceous Oceanic Anoxic Event 2 (OAE2) indicate that the ocean redox state was temporally and spatially heterogeneous. Its evolution is considered to be induced by the variation of atmospheric carbon dioxide concentrations (<em>p</em>CO₂) due to the activities of large igneous provinces (LIPs) and associated changes in global meridional overturning circulation, nutrient input, and phosphorus recycling. However, their respective roles on the OAE2 are still under debate. Here, we conduct transient numerical simulations using an intermediate-complexity Earth system model with reconstructed <em>p</em>CO₂ values. In our simulations, bottom anoxia occurred in the equatorial Atlantic Ocean and the Tethyan rim before OAE2. This changed only slightly with varying <em>p</em>CO₂. In contrast, increasing nutrient concentrations due to increased continental weathering can lead to a marked increase in anoxic areas, which is further expanded by enhanced phosphorus recycling in the low-oxygen marine area. The North Atlantic, low-latitude South Atlantic, Southeast Pacific, and Western Tethys oceans are most prone to developing bottom water anoxia. The modeled anoxic areas exhibit distinctly different spatio-temporal patterns during OAE2 with varying weathering intensities. Comparison of the simulation results with newly assembled geological records suggests that anoxic bottom water only accounted for ∼20–40% of the global bottom area and that the continental phosphorus weathering intensity was increased by ∼40–60% compared to the pre-OAE2 level.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"253 ","pages":"Article 104976"},"PeriodicalIF":4.0,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144613373","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":"Sources, transport, age, and evolution of terrestrial organic carbon across the Chukchi Sea margin, Arctic Ocean","authors":"Peng Ren ,&nbsp;Claude Hillaire-Marcel ,&nbsp;Mengmeng Wang ,&nbsp;Sen Shan ,&nbsp;Song Zhao ,&nbsp;Tengfei Song ,&nbsp;Linsen Dong ,&nbsp;Xuchen Wang ,&nbsp;Yanguang Liu","doi":"10.1016/j.gloplacha.2025.104978","DOIUrl":"10.1016/j.gloplacha.2025.104978","url":null,"abstract":"<div><div>Global warming and permafrost thawing are expected to release substantial amounts of organic carbon (OC) into the Arctic Ocean, potentially intensifying climate warming through a positive feedback loop. In our study, we investigated the sources, transport, and evolution of terrestrial OC (terr-OC) across the Chukchi Sea margin in the Arctic Ocean, using carbon isotope (¹³C and ¹⁴C) and biomarker (<em>n</em>-alkanes and lignin) analyses. Our findings revealed that terr-OC from various sources, such as Ice Complex Deposits (ICD), topsoil, and high plants, was stored and evolved across the Chukchi continental marginal seas. A dual‑carbon-isotope mixing model indicated that ICD was the dominant terr-OC source (47 ± 21 %) in sediments, with its contribution increasing from the Chukchi shelf to the slope. While, the proportion of topsoil-OC (18 ± 7 %) decreased with distance and over time along the Chukchi slope. The enriched Δ¹⁴C values and higher molecular degradation proxies on the Chukchi shelf suggested that a large proportion of the exogenous terr-OC had undergone significant degradation before reaching the sediment-water interface. During transport, selective degradation occurred, with lignin and <em>n</em>-alkanes declining faster than TOC, and topsoil-OC degrading rapidly than ICD-OC. This prolonged transport likely intensified selective degradation, as changes in terr-OC across the Chukchi shelf to slope were more noticeable than in vertical sediment core profiles. This study emphasizes the Arctic Ocean as a critical sink for diverse forms of terr-OC and highlights the importance of lateral transport, deposition, and degradation in OC burial processes. Further research on precise temporal scales is needed to clarify whether the observed spatial differences stem from variations in sediment sources or from the combined effects of hydrodynamic sorting and selective degradation during lateral transport.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"253 ","pages":"Article 104978"},"PeriodicalIF":4.0,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144605867","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":"A Late Glacial and Holocene sugar biomarker-based δ18O paleoclimate record from the Afro-alpine Central Lake, Bale Mountains, Ethiopia","authors":"Samuel G. Chernet ,&nbsp;Lucas Bittner ,&nbsp;Graciela Gil-Romera ,&nbsp;Bruk Lemma ,&nbsp;Marcel Bliedtner ,&nbsp;Roland Zech ,&nbsp;Bruno Glaser ,&nbsp;Tobias Bromm ,&nbsp;Sönke Szidat ,&nbsp;Wolfgang Zech ,&nbsp;Michael Zech","doi":"10.1016/j.gloplacha.2025.104975","DOIUrl":"10.1016/j.gloplacha.2025.104975","url":null,"abstract":"<div><div>The Eastern African region is an amalgamation of complex climate systems nestled in contrasting topographic barriers. Although rift basins are prime targets for studying the climate of the past, high-altitude climate archives in the context of paleoclimate research also offer invaluable insight and have yet to be fully explored. Here, we present a 17 kyr hydroclimate history of the Afro-alpine (4121 m a.s.l) Central Lake using a δ¹⁸O record established by analyzing hemicellulose-derived sugar biomarkers. The sugar biomarker patterns with a dominance of fucose indicate the predominance of autochthonous sedimentary organic matter. Therefore, the oxygen isotopic variability of the sugar biomarkers in general and of fucose in particular (δ¹⁸O_fucose) reflects δ¹⁸O_{lake water} being controlled by climatic conditions, particularly lake water ¹⁸O enrichment by evaporation. Our δ¹⁸O_fucose record from Central Lake indicates strong enrichment during the Late Glacial. Around 15 cal kyr BP, the onset of more humid climate marks the beginning of the African Humid Period (AHP) in the Bale Mountains. The AHP was interrupted by an arid period during the Late Glacial – Holocene transition roughly coinciding with the Younger Dryas (YD). After the YD, humid climatic conditions prevailed again until the Late Holocene when a gradual shift towards drier climate started. Our δ¹⁸O_fucose record and interpretation agree well with the findings from adjacent low-altitude archives of Eastern Africa, the Indian Ocean paleoclimate records and the Asian Monsoon Domain, which suggests region-wide hydro-climatic teleconnections.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"253 ","pages":"Article 104975"},"PeriodicalIF":4.0,"publicationDate":"2025-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144587726","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":"Diapycnal fluxes of nutrients in the North Pacific Subtropical Gyre","authors":"Chuanjun Du ,&nbsp;Minhan Dai ,&nbsp;Zhiyu Liu ,&nbsp;Zhendong Hu ,&nbsp;Jin-Yu Terence Yang ,&nbsp;Kuanbo Zhou ,&nbsp;Hongyang Lin ,&nbsp;Zhongwei Yuan ,&nbsp;Lifang Wang ,&nbsp;Tao Huang ,&nbsp;Liguo Guo ,&nbsp;Zhe Wang ,&nbsp;Shuh-Ji Kao","doi":"10.1016/j.gloplacha.2025.104973","DOIUrl":"10.1016/j.gloplacha.2025.104973","url":null,"abstract":"&lt;div&gt;&lt;div&gt;The supply of nutrients via diapycnal processes from depth to the euphotic zone (EZ) is thought to be a main source sustaining new production in oligotrophic oceans. However, such diapycnal fluxes of nutrients remain insufficiently constrained due to limited observations and the dynamic nature of ocean turbulence. In this study, we present a comprehensive dataset of diapycnal fluxes of nutrients, including diapycnal diffusive (&lt;em&gt;F&lt;/em&gt;&lt;sub&gt;&lt;em&gt;diff_NOx&lt;/em&gt;&lt;/sub&gt;) and effective diapycnal fluxes (&lt;em&gt;F&lt;/em&gt;&lt;sub&gt;&lt;em&gt;e_NOx&lt;/em&gt;&lt;/sub&gt;, representing the net diapycnal influx to the upper water column) of NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt; + NO&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt; (NO&lt;sub&gt;x&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;), based on measurements of turbulence microstructure and nutrients with high vertical resolutions from two cruises conducted during summer and winter in the oligotrophic western North Pacific Subtropical Gyre (NPSG). The &lt;em&gt;F&lt;/em&gt;&lt;sub&gt;&lt;em&gt;diff_NOx&lt;/em&gt;&lt;/sub&gt; (&lt;em&gt;F&lt;/em&gt;&lt;sub&gt;&lt;em&gt;e_NOx&lt;/em&gt;&lt;/sub&gt;) exhibits evident spatial variations, with higher values observed at the south boundary of the NPSG near the North Equatorial Current and at the northern NPSG influenced by the North Pacific Tropical Subtropical Mode Water. In contrast, lower values are found in the central NPSG. These spatial variations are primarily attributable to the vertical concentration gradient of NO&lt;sub&gt;x&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;. At the base of the EZ, the cruise-averaged &lt;em&gt;F&lt;/em&gt;&lt;sub&gt;&lt;em&gt;diff_NOx&lt;/em&gt;&lt;/sub&gt; (&lt;em&gt;F&lt;/em&gt;&lt;sub&gt;&lt;em&gt;e_NOx&lt;/em&gt;&lt;/sub&gt;) are 11.7 ± 9.6 (11.9 ± 8.6) and 8.5 ± 6.1 (11.3 ± 9.3) μmol m&lt;sup&gt;−2&lt;/sup&gt; d&lt;sup&gt;−1&lt;/sup&gt; in summer and winter, respectively, displaying insignificant seasonal variations. Moreover, we observed significantly higher flux ratios of &lt;em&gt;F&lt;/em&gt;&lt;sub&gt;&lt;em&gt;diff_NOx&lt;/em&gt;&lt;/sub&gt; to diapycnal diffusive flux of phosphate (&lt;em&gt;F&lt;/em&gt;&lt;sub&gt;&lt;em&gt;diff&lt;/em&gt;_DIP&lt;/sub&gt;), which were 18.2 ± 2.0 and 13.9 ± 2.0, compared to the N/P concentration ratios of 10.4 ± 1.1 and 7.4 ± 1.2 at the base of the EZ during summer and winter cruises, respectively, suggesting that the diapycnal transport could relieve nitrogen limitation in the upper NPSG. Notably, we identified strong linear relationships between the logarithm of &lt;em&gt;F&lt;/em&gt;&lt;sub&gt;&lt;em&gt;diff_NOx&lt;/em&gt;&lt;/sub&gt; (&lt;em&gt;F&lt;/em&gt;&lt;sub&gt;&lt;em&gt;e_NOx&lt;/em&gt;&lt;/sub&gt;) and the NO&lt;sub&gt;x&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt; gradient. Leveraging these relationships, we estimate the climatological distributions of &lt;em&gt;F&lt;/em&gt;&lt;sub&gt;&lt;em&gt;diff_NOx&lt;/em&gt;&lt;/sub&gt; (&lt;em&gt;F&lt;/em&gt;&lt;sub&gt;&lt;em&gt;e_NOx&lt;/em&gt;&lt;/sub&gt;) utilizing nutrient data from the World Ocean Atlas (WOA23). The &lt;em&gt;F&lt;/em&gt;&lt;sub&gt;&lt;em&gt;e_NOx&lt;/em&gt;&lt;/sub&gt; is estimated to be 20.2 ± 16.6 μmol m&lt;sup&gt;−2&lt;/sup&gt; d&lt;sup&gt;−1&lt;/sup&gt; and contributes to 8.5 ± 8.3 % of the nitrogen required for new production in the NPSG. These estimates are slightly lower than previous studies, but highlight that diapycnal fluxes play a less important role on nitrogen budget compared to N&lt;sub&gt;2&lt;/sub&gt;-fixation and atmospheric deposition in the oligotrophic NPSG. In contrast, the ef","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"253 ","pages":"Article 104973"},"PeriodicalIF":4.0,"publicationDate":"2025-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144613369","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":"Spatio-temporal changes in interannual sea level along the world coastlines","authors":"Lancelot Leclercq, Habib B. Dieng, Anny Cazenave, Florence Birol, Julius Oelsmann, Marcello Passaro, Svetlana Jevrejeva, Erwin Bergsma, Sarah Connors","doi":"10.1016/j.gloplacha.2025.104972","DOIUrl":"https://doi.org/10.1016/j.gloplacha.2025.104972","url":null,"abstract":"To investigate how coastal sea level evolves at interannual time scales from one region to another, we perform an Empirical Orthogonal Function (EOF) decomposition of coastal sea level time series derived from reprocessed coastalaltimetry data over a 20-year long time span (2002−2021), at 1132 virtual coastal stations homogeneously distributed along the world coastlines. This analysis is first performed globally and then over selected coastal regions. Consistent with previous studies, the results show the dominant influence of internal climate modes, in particular ENSO (El Niño Southern Oscillation), on the interannual coastal sea level variability. But our study also reports novel findings in coastal sea level: (1) a regime shift between 2008 and 2012, with increased sea level rate after that date in many coastal regions, and (2) a 6-year cycle, notably along the northeast and northwest coasts of America (north of 40°) and along the Indian coast of Indonesia. Additional EOF analyses are done using both gridded altimetry sea level data from the Copernicus Climate Change Service and an ensemble mean of four ocean reanalyses, in three successive coastal bands: 0-50 km, 50-100 km and 100-500 km from land. They confirm the strong influence of internal climate modes at the coast but also show that results in the cross-shore direction towards the open ocean are similar to those at the coast. This study based on three different datasets shows that the strong influence of internal climate modes on sea level interannual variability in the world coastal zones is not limited to the open ocean but also dominates sea level changes very close to the coast It also shows evidence of a regime shift in the rate of change of coastal sea level between 2008 and 2012 and the presence of a 6-year oscillation in coastal sea level, possibly linked to the recent discovery of a 6-year cycle in the whole climate system.","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"275 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144613371","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}