Global and Planetary Change最新文献

{"title":"Late Paleozoic climate transition from a long-term carbon cycle modeling perspective","authors":"Chloé M. Marcilly ,&nbsp;Trond H. Torsvik ,&nbsp;Morgan T. Jones","doi":"10.1016/j.gloplacha.2025.104984","DOIUrl":"10.1016/j.gloplacha.2025.104984","url":null,"abstract":"<div><div>The Late Paleozoic ice age (LPIA) is the longest-lived Phanerozoic icehouse climate and the only recorded greenhouse–icehouse–greenhouse cycle on a vegetated Earth. Sedimentary archives partially detail the glaciation events, but the reasons and timing of the LPIA's onset (∼330 Ma) and end (∼260 Ma) remain debated. In many models, the shift to icehouse conditions is linked to enhanced CO₂ uptake through silicate weathering, but the causes of this increased carbon sink are unclear. Most carbon cycle models are limited by their non-dimensional nature, and spatially resolved models rely heavily on variables such as topography and bathymetry, which are difficult to constrain over time. This study investigates the influence of weatherability reconstructions in non-dimensional versus spatially resolved models in the context of the LPIA's onset and ending. We review constraints on simulated silicate weathering fluxes and test forcings affecting its rate. Our paleogeographic forcing review uses newly developed land-maps and reconstructed climatic belts to constrain weathering based on fossil paleo-indicators. Our findings suggest that increased land availability in the high weatherability zones (HWZ) led to enhanced weathering processes, likely contributing to the glaciation onset. However, when a high solid Earth degassing factor is included, the likelihood of an extensive glaciation diminishes, indicating the need for an intensified CO₂ sink driven by higher erosion rates and associated chemical weathering tied to topographic elevation to instigate widespread glaciation. A reduction in available land for weathering in the HWZ appears to have a determining role in the LPIA's termination.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"253 ","pages":"Article 104984"},"PeriodicalIF":4.0,"publicationDate":"2025-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144665145","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":"Differentiation between Fe and Sc in phyllosilicate clays as a proxy for redox state of weathering front","authors":"Shenghui Ouyang ,&nbsp;Mengnan Liu ,&nbsp;David William Hedding ,&nbsp;Gaojun Li","doi":"10.1016/j.gloplacha.2025.104985","DOIUrl":"10.1016/j.gloplacha.2025.104985","url":null,"abstract":"<div><div>The redox state of weathering front plays a critical role in determining the structure and functions of the Earth's critical zone. Characterizing the redox state of weathering front, however, is challenging due to the thick regolith coverage that generally prevents direct observation. The heterogeneity of parent rock lithology and development of macro fractures conducive to fluid/gas would also result in small scale changes in the redox state at weathering front. This work studies the differentiation between Fe and Sc in phyllosilicate clays as aproxy to assess the redox state of weathering front on catchment scale. The method is based on the fact that Fe released during weathering is rapidly oxidized into iron oxides and hydroxides while Sc is mainly incorporated into phyllosilicate clays in an oxidative weathering environment. In contrast, under a reductive weathering environment, the Fe²⁺ released by weathering is readily incorporated into the lattice of phyllosilicate clays together with Sc. Subsequent dissolution of phyllosilicate clays in the regolith would congruently release the Fe and Sc which eventually be incorporated into iron oxides and hydroxides. Thus, the Fe/Sc ratio of phyllosilicate clays would keep its initial value at the weathering front regardless of subsequent alteration. Catchments comprised of crystalline bedrock with contrasting lithologies in Hainan Island, China, were investigated to test the new proxy. The relatively thin regolith developed over mafic bedrocks compared to that developed over felsic bedrocks indicates lithological control on the redox state of weathering fronts. In catchments dominated by mafic bedrock, a substantial portion of Fe released by weathering is preserved into phyllosilicate clays. In contrast, only a small fraction of the Fe released by weathering retained in the autochthonous phyllosilicate clays in felsic catchments. The contrasting behavior of Fe between the mafic and felsic catchments indicates lithological control on the redox state of weathering fronts, and thus the partitioning of Fe between phyllosilicate clays and iron oxides/hydroxides. The new method provided by this study can be used to trace the redox state of weathering fronts for both the past and present-day conditions of critical zones of the Earth.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"253 ","pages":"Article 104985"},"PeriodicalIF":4.0,"publicationDate":"2025-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144665079","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":"Lithium isotopes as a chemical weathering proxy in lacustrine sediments: Implications from multiphase leaching analyses","authors":"Yudong Liu ,&nbsp;Yibo Yang ,&nbsp;Zhongyi Yan ,&nbsp;Zhangdong Jin ,&nbsp;Chengcheng Ye ,&nbsp;Philip A.E. Pogge von Strandmann ,&nbsp;Li Deng ,&nbsp;Xiaoming Liu ,&nbsp;Xiaomin Fang","doi":"10.1016/j.gloplacha.2025.104986","DOIUrl":"10.1016/j.gloplacha.2025.104986","url":null,"abstract":"<div><div>Reconstructing the history of continental silicate weathering is critical for understanding the mechanism that maintains Earth's habitability. Lithium (Li) isotopes have become a valuable indicator for tracing silicate weathering because of their negligible interference from carbonate and parent rock type. Although substantial effort has focused on the use of Li isotopes as a weathering proxy in marine settings, Li isotope distributions within terrestrial sediments remain largely unexplored. Here, we use a sequential leaching method to characterize Li isotopes across different phases of lacustrine sediments from the Qaidam Basin. The phases include the soluble salt, exchangeable, carbonate, silicate, and clay fractions. The results revealed that, compared with 0.05 M hydrochloric acid, 1 M acetic acid effectively extracted carbonates with minimal silicate contamination. The soluble salts and carbonates present similarly high and positively correlated δ⁷Li values, implying that these authigenic minerals reflect the dissolved Li isotopic composition of the palaeolake. The silicates in the whole rock and clay-size phases display similarly low δ⁷Li values and may capture trends in the Li isotopic compositions of weathering-related alteration products. However, both phases may overestimate the δ⁷Li value of the weathering-related alteration products by approximately 0.4–1.3 ‰ because of the presence of unweathered detrital minerals (e.g., quartz and feldspar). This study underscores the potential of multiphase Li isotope investigations in lacustrine sediments to yield integrated Li isotope signals from weathering solutions and alteration products, highlighting the importance of Li isotopes in terrestrial sediments for reconstructing catchment-scale silicate weathering histories.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"253 ","pages":"Article 104986"},"PeriodicalIF":4.0,"publicationDate":"2025-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144665077","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":"Climate-modulated paleoceanographic changes in the Alboran Basin triggered by tectonic restriction at the Atlantic–Mediterranean Seaway during the Tortonian–Messinian transition","authors":"F. Lanterna ,&nbsp;F. Bulian ,&nbsp;F.J. Sierro ,&nbsp;A. Mulch ,&nbsp;I. Vasiliev","doi":"10.1016/j.gloplacha.2025.104982","DOIUrl":"10.1016/j.gloplacha.2025.104982","url":null,"abstract":"<div><div>The evolution of restricted marine basins offers unique insights into the interplay between climatic variability and tectonic processes. This study focuses on the western Mediterranean Sea, which underwent progressive isolation beginning in the late Tortonian (∼8 Ma) and culminating with the Messinian Salinity Crisis (5.97–5.33 Ma), when the basin experienced quasi-disconnection from the Atlantic Ocean. Here, we present reconstructions of sea surface temperature and salinity derived from coupled analysis of organic biomarkers and oxygen isotopes on planktic foraminifera from the West Alboran Sea (ODP site 976B) for the 7.505 to 7.063 Ma time interval. The combined results show four phases with distinct paleoenvironmental conditions prevailing in this westernmost Mediterranean. During Phase 1 (7.505–7.369 Ma), the sea surface temperatures showed low-frequency, large-amplitude fluctuations (25.7 to 29.7 °C) accompanied by large sea surface salinity variations (37.1 to 43.3). In Phase 2 (7.369–7.241 Ma), the marine conditions shifted to low variability, high sea surface temperatures (27.9 to 29.6 °C) accompanied by stable and high salinities (42.7 to 43.7). In Phase 3 (7.241–7.177 Ma), stable hypersaline conditions (43.0 to 44.3) persisted alongside an even lower variability in sea surface temperatures (28.3 to 29.1 °C). Phase 4 (7.177–7.063 Ma) is marked by a pronounced cooling and unexpected freshening. During Phase 4, the large-amplitude, high-frequency sea surface temperature (25.3 to 29.8 °C) and sea surface salinity changes (35.9 to 44.0) were likely driven by the progressive closure of the Betic and Rifian gateways around 7.1 Ma, with a superimposed precession modulation. This study highlights the sensitivity of the Western Mediterranean Basin to gateway restrictions and provides a framework for understanding the broader climatic and oceanographic impacts of tectonically triggered restriction events. The system was highly sensitive to global climate variations, especially during the latest Tortonian, when the Alboran basin had a fully functional connection to the Atlantic. Starting with the earliest Messinian, changes in connectivity through the Atlantic–Mediterranean gateway likely played a pivotal role in regulating temperature and salinity of the western Mediterranean with consequences propagating further to the east, in the entire basin.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"253 ","pages":"Article 104982"},"PeriodicalIF":4.0,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144665080","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":"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":"Editorial preface to special issue: Applying palaeoenvironmental data to inform resource management and planning","authors":"Chris Gouramanis ,&nbsp;Kathryn J. Allen ,&nbsp;Dave Sauchyn","doi":"10.1016/j.gloplacha.2025.104981","DOIUrl":"10.1016/j.gloplacha.2025.104981","url":null,"abstract":"<div><div>The cornerstone of effective public policy and decision-making relies on robust, fit-for-purpose data that typically extend beyond recent, very short-term monitoring and observation. This is true in fields as diverse as pollution, climate change, climate and geophysical hazards, biodiversity conservation, and water and natural resource management. Accurate, time-stamped data is particularly important when considering the resilience or rates of change that our systems must absorb before thresholds for active intervention are crossed. Fortunately, analysis of palaeo-archives is providing longer-term information prior to observational or monitoring efforts. Longer-term data can be informative as standalone records or can be compiled into regional syntheses underpinning modelling exercises. In this Virtual Special Issue (VSI) entitled <em>Applying palaeoenvironmental data to inform resource management and planning</em>, we compile eight studies that reinforce the value of palaeo-knowledge for appropriate decision-making and policy development. The studies span very different time frames from historical through to deep time and across many different spheres of policy and decision-making. This VSI barely scratches the surface of the potential that palaeo-information can provide when considered with an application-focused lens, and demonstrates the critical importance of long-term datasets for decision-making.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"253 ","pages":"Article 104981"},"PeriodicalIF":4.0,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144665081","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}