{"title":"Why Does the Norwegian Sea-Barents Sea Region Have the Smallest Amount of Stratocumulus in Summer?","authors":"Ru Zhou, Yunyin Li, Zhiwei Zhang, Lei Zhu, Naifu Shao, Wenrong Bai, Chen Zhou, Chunsong Lu, Mengyu Huang, Ping Tian","doi":"10.1029/2025GL116907","DOIUrl":"10.1029/2025GL116907","url":null,"abstract":"<p>The melting of sea ice in the Arctic has sparked research into how clouds form in exposed ice-free zones. This study delves into the seasonal distribution of stratocumulus clouds over the Norwegian Sea-Barents Sea region and presents a conceptual model for the underlying mechanisms. In spring, autumn, and winter, increased surface water vapor flux provides water vapor from the sea surface. Concurrently, warm air enters the area through the southwest wind of the Norwegian Strait. Under conditions of unstable stratification, the water vapor is lifted to the condensation level, promoting the formation of stratocumulus clouds. Conversely, in summer, evaporation is suppressed due to stable stratification, which hinders vertical vapor transport. Enhanced dry advection reduces the transport of water vapor, leading to a decrease in the amount of stratocumulus clouds during summer. This research enriches our understanding of the physical mechanisms influencing cloud formation and cloud-climate feedbacks in the Arctic region.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 20","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025GL116907","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145306310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Reale, A. Raganato, F. D'Andrea, M. Adnan Abid, A. Hochman, N. R. Chowdhury, S. Salon, F. Kucharski
{"title":"Response of Early Winter Precipitation and Storm Activity in the North Atlantic–European–Mediterranean Region to Indian Ocean SST Variability","authors":"M. Reale, A. Raganato, F. D'Andrea, M. Adnan Abid, A. Hochman, N. R. Chowdhury, S. Salon, F. Kucharski","doi":"10.1029/2025GL116732","DOIUrl":"10.1029/2025GL116732","url":null,"abstract":"<p>We investigate the response of winter precipitation and storm activity in the North Atlantic–European–Mediterranean region (NAEM) to the Indian Ocean Dipole (IOD) from 1979 to 2024. We observe a positive NAO-like pattern over NAEM, which appears in December and shifts eastward through February. IOD further modulates precipitation by inducing changes in total precipitation, event frequency, and wet spell duration. The strength of the observed teleconnection is primarily significant in December. Additionally, we observe a reduction in cyclone activity in December over the East Atlantic and Western Mediterranean. These changes in cyclone track density are primarily driven by variations in the Eady Growth Rate, which are linked to enhanced vertical wind shear associated with a strengthened meridional temperature gradient over the NAEM. The results underscore a significant remote impact of the IOD on early winter hydro-climate variability over the NAEM region, offering a potential value for improving sub-seasonal to seasonal prediction.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 20","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025GL116732","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145295969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Mapping Basin Interfaces Using Single-Station Cross-Component Correlations: Application to the Central Vienna Basin (Austria)","authors":"C. Esteve, Y. Lu, G. Bokelmann","doi":"10.1029/2025GL116888","DOIUrl":"10.1029/2025GL116888","url":null,"abstract":"<p>We calculate cross-component correlations and receiver functions from teleseismic earthquakes recorded by a seismic nodal array deployed in the central Vienna Basin, Austria. The two methods show similar results. Those results highlight two main layer boundaries between the surface and 15 km depth. We attribute the first layer boundary to the Aderklaa Conglomerate Formation within the Neogene basin and the second layer boundary to the top of the crystalline basement in the area. A vertical offset along the profile potentially highlights two local tectonic faults. This study contributes to the understanding of the subsurface structure in the Vienna Basin, with implications for regional tectonic processes and resource exploration. The cross-component correlation method demonstrates strong potential for resolving interfaces in complex sedimentary environments.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 20","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025GL116888","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145306309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jinqiao Fan, Yasong S. Ge, Can Huang, Aimin Du, Xiaohua Fang, Tielong Zhang, Yingjuan Ma, Lei Wang, Ziyong Liu
{"title":"Magnetic Flux Ropes at Mars and Their Impacts on Heavy Ion Escape","authors":"Jinqiao Fan, Yasong S. Ge, Can Huang, Aimin Du, Xiaohua Fang, Tielong Zhang, Yingjuan Ma, Lei Wang, Ziyong Liu","doi":"10.1029/2025GL116027","DOIUrl":"10.1029/2025GL116027","url":null,"abstract":"<p>Flux ropes (FRs), ubiquitous helical magnetic structures in solar system plasmas, are important to energy and particle transport. At Mars, where global intrinsic magnetic fields are absent, FRs form through magnetic reconnection (MR) and magnetospheric or ionospheric boundary wave instabilities (BWIs), but their role in ion escape remains controversial. Here, we first present the global distribution of MR- and BWI-FRs from Martian ionosphere to magnetosheath, utilizing 4,012 FR events identified from 5-year observations by the Mars Atmosphere and Volatile EvolutioN (MAVEN) satellite. We find that the global occurrence rate of FRs associated with BWIs is comparable with those from MR. Enhanced oxygen ion outflow fluxes and densities within most nightside BWI-FRs suggest they predominantly originate from the dayside ionosphere/magnetosphere. These BWI-FRs have sufficient magnetic field intensity to carry oxygen ions beyond escape energies, suggesting their potential role in facilitating global ion escape from Mars via magnetotail transport.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 20","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025GL116027","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145295218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chandra Rupa Rajulapati, Alex Crawford, Simon Michael Papalexiou, Julienne Stroeve
{"title":"Prevailing Climate Patterns for Concurrent High Temperature and Low Precipitation Days in Canada","authors":"Chandra Rupa Rajulapati, Alex Crawford, Simon Michael Papalexiou, Julienne Stroeve","doi":"10.1029/2025GL118662","DOIUrl":"10.1029/2025GL118662","url":null,"abstract":"<p>In this work, we evaluated the changing frequency of concurrent daily High Temperature and Low Precipitation (HTLP) and its relationship with large-scale climate patterns across Canada. Our analysis showed a significant increase (up to 3 days/decade) in the Canadian Arctic and southern regions of British Columbia and an insignificant decrease in HTLP frequency in the Prairies of Saskatchewan and Manitoba during 1979–2018. We examined ten large-scale climate patterns influencing precipitation and temperature in Canada. Among these, four climate indices (the East Pacific-North Pacific Pattern, North Atlantic Oscillation, Oceanic Niño Index, and East Atlantic Pattern) were noted as significant influencers of HTLP frequency, ranked in descending order of influence. Our research holds significance in explaining the spatial dynamics of HTLP days and the role of large-scale climate patterns therein, providing valuable insights for future research on heatwaves and droughts, mitigation efforts, and policy changes tailored to vulnerable regions.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 20","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025GL118662","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145295221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Multi-Year Ice Dynamics at Køge Bugt Central Glacier Controlled by Bed Topography","authors":"H. J. Picton, P. W. Nienow","doi":"10.1029/2025GL116829","DOIUrl":"10.1029/2025GL116829","url":null,"abstract":"<p>Køge Bugt Central (KBC) is Greenland's fourth largest outlet glacier in terms of ice discharge. However, the drivers behind its substantial multi-year variations in ice dynamics remain unknown. In this study, we use remotely sensed data sets of ice surface velocity, ice surface elevation, ice discharge, and terminus position, in combination with modeled estimates of surface runoff and ocean thermal forcing, to explore variations in its ice dynamics between 2016 and 2024. Our results indicate that KBC functions as a self-organizing system, whereby an underlying bedrock ridge serves as a critical pinning point around which it oscillates. Terminus retreat occurs when the glacier reaches a <i>super</i>-<i>critical</i> state, with strong evidence for buoyancy-driven calving observed. Whilst KBC is currently stabilized by the bedrock ridge, sustained thinning will eventually remove this critical control on ice flow, likely initiating a fundamental shift in ice dynamics and rendering KBC more susceptible to future climatic change.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 20","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025GL116829","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145306085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Robin Guillaume-Castel, Paulo Ceppi, Joshua Dorrington, Benoit Meyssignac
{"title":"ENSO Diversity Explains Interannual Variability of the Pattern Effect","authors":"Robin Guillaume-Castel, Paulo Ceppi, Joshua Dorrington, Benoit Meyssignac","doi":"10.1029/2025GL116952","DOIUrl":"10.1029/2025GL116952","url":null,"abstract":"<p>The spatial pattern of sea surface temperature (SST) affects the global radiative budget through the “pattern effect.” While previous studies highlighted the role of El Niño–Southern Oscillation (ENSO) in unforced pattern effect, a systematic assessment of the dominant modes of SST variability for the top of atmosphere energy budget has been lacking. Using Partial Least Squares Regression, we identify Eastern Pacific and Modoki ENSO as the two leading modes most relevant to the pattern effect at interannual timescales. These ENSO variants exhibit distinct radiative signatures due to subtle shifts in the location of SST anomalies relative to the climatological warm pool. Furthermore, analysis of individual ENSO events indicates that each event has a unique radiative signature depending on its evolving spatial structure. These findings highlight the importance of accounting for ENSO diversity to accurately understand how modes of SST variability influence the global energy budget.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 20","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025GL116952","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145306312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Possible Mechanisms for the Record-Breaking Persistent Extreme Rainfall Event Over Southern China in April 2024: Synergistic Effects of Multiscale Systems","authors":"Wenqi Pan, Jianqi Sun, Jiehua Ma","doi":"10.1029/2025GL116189","DOIUrl":"10.1029/2025GL116189","url":null,"abstract":"<p>In April 2024, southern China suffered a record-breaking persistent extreme rainfall event (PERE), affecting 1.60 million people and causing direct economic losses of 11.98 billion RMB. This study reveals the synergistic effects of sea surface temperature (SST) and intraseasonal atmospheric circulation. Positive SST anomalies in tropical Indian Ocean (TIO) strengthen the western Pacific subtropical high (WPSH) via Gill-type response (basical theory describing the atmospheric response to external forces such as tropical SST), enhancing moisture transport to southern China. The 10–30-day intraseasonal oscillation (ISO) along the subtropical westerly jet initiates the event by inducing a low-pressure and ascending motion over southern China. The 30–90-day ISO along the polar front jet sustains the event by intensifying East Asian westerly jet and maintaining ascending motion over southern China. Furthermore, North Atlantic SST anomalies enhance North Atlantic jet stream, promoting downstream propagation of intraseasonal wave trains via energy conversion.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 20","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025GL116189","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145295880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Long-Term Trends of Ionospheric Day-to-Day Variability During the Past Century","authors":"Xu Zhou, Wenbo Li, Huixin Liu, Lianhuan Hu, Yi Li, Xinan Yue","doi":"10.1029/2025GL118640","DOIUrl":"10.1029/2025GL118640","url":null,"abstract":"<p>In this study, we explore the long-term trend of ionospheric day-to-day variability induced by atmospheric perturbations over the past century, using time-slice simulations by the whole atmospheric model. The main results show that the magnitude of the trends in the past century maximizes ∼±1% of the seasonal mean per decade. Analysis of the contributing factors reveals that geomagnetic secular variation primarily contributes to the trends over the American-Atlantic sector, while increasing greenhouse gases (GHG) explain most trend patterns over the Asia-Pacific region. Additional evidence by Wuhan ionosonde observations covering the period of 1947–2024, supports the simulated negative trend, and the magnitude agrees well with the simulations. Furthermore, our analysis of atmospheric tides revealed that the weakening of SE2 day-to-day variability due to increasing GHG levels is a plausible cause. Our findings thus indicate that ionospheric weather-like variability also undergoes long-term trends significantly under the climate change scenario.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 20","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025GL118640","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145295223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yuhei Takaya, Naresh G. Ganeshi, Yu Kosaka, X. San Liang, Tomonori Sato
{"title":"Influence of Soil Moisture on Surface Air Temperature in Monsoons","authors":"Yuhei Takaya, Naresh G. Ganeshi, Yu Kosaka, X. San Liang, Tomonori Sato","doi":"10.1029/2025GL115760","DOIUrl":"10.1029/2025GL115760","url":null,"abstract":"<p>Land plays a pivotal role in modulating weather and climate in monsoon regions, yet our understanding of land–atmosphere interactions remains incomplete. Here we present the information-theoretic causal analysis, the Liang-Kleeman information flow, for quantifying the strength of soil moisture (SM) influence on surface air temperature (SAT). We revealed that SM exerts significant influence on SAT across monsoon regions, intricately linked to the seasonal monsoon cycle. Notably, prominent influence of SM on SAT was found, even under typical wet conditions in the tropics when intense solar radiation is present. Furthermore, this study highlights a strong connection between land desiccation and the occurrence of hot days in pre-monsoon periods. The proposed measure of SM influence strength enhances our understanding of land–atmosphere interactions and provides new insights into seasonally evolving predictability arising from SM variability across monsoon systems.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 20","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025GL115760","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145305894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}