Climate Dynamics最新文献

{"title":"Influence of global climate modes on wildfire occurrence in the contiguous United States under recent and future climates.","authors":"Theodore R Keeping, Theodore G Shepherd, I Colin Prentice, Karin van der Wiel, Sandy P Harrison","doi":"10.1007/s00382-025-07998-w","DOIUrl":"10.1007/s00382-025-07998-w","url":null,"abstract":"<p><p>Predictable modes of climate variability, such as the El Niño Southern Oscillation (ENSO), have a major influence on regional weather patterns, an important control on wildfire occurrence. Although these global climate modes have been associated with historical variability in wildfire occurrence in the United States and are used to forecast seasonal wildfire risk, precise information about the spatial pattern and magnitude of their influence is lacking and the satellite record of wildfires is too short to address these issues. Here we use wildfire occurrence model with a large ensemble of 1600 simulated years from EC-Earth3 in a recent climate (2000-2009) and a future climate corresponding to + 2 °C global warming, to characterise the impact of specific climate modes on wildfire occurrence in the contiguous US. We show that ENSO, the Indian Ocean Dipole (IOD), and the 1-year lagged Tropical North Atlantic (TNA+1) have the greatest effect on annual fire occurrence-strongly contributed by the effect of these modes on hot, dry conditions in the Great Plains and precipitation in the southwestern US. El Niño is not significantly associated with wildfire occurrence in the northwestern US, contrary to expectation, but is associated with a later (earlier) wildfire season peak in the southwestern (southeastern) US. Under future warming, the AMO and PNA become a significant influence over most of the US, and the magnitude of impact of ENSO and TNA+1 increase strongly.</p><p><strong>Supplementary information: </strong>The online version contains supplementary material available at 10.1007/s00382-025-07998-w.</p>","PeriodicalId":10165,"journal":{"name":"Climate Dynamics","volume":"64 1","pages":"15"},"PeriodicalIF":3.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12717122/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145803390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Seasonal forecasting using the GenCast probabilistic machine learning model.","authors":"Bobby Antonio, Kristian Strommen, Hannah M Christensen","doi":"10.1007/s00382-026-08077-4","DOIUrl":"https://doi.org/10.1007/s00382-026-08077-4","url":null,"abstract":"<p><p>Machine-learnt weather prediction (MLWP) models are now well established as being competitive with conventional numerical weather prediction (NWP) models in the medium range. However, there is still much uncertainty as to how this performance extends to longer timescales, where interactions with slower components of the earth system become important. We take GenCast, a state-of-the-art probabilistic MLWP model, and apply it to the task of seasonal forecasting with prescribed sea surface temperature (SST), by providing anomalies persisted over climatology (GenCast-Persisted) or forcing with observed SSTs (GenCast-Forced). The forecasts are compared to the European Centre for Medium-Range Weather Forecasts seasonal forecasting system, SEAS5. Our results indicate that, despite being trained at short timescales, GenCast-Persisted produces much of the correct precipitation patterns in response to El Niño and La Niña events, with several erroneous patterns in GenCast-Persisted corrected with GenCast-Forced. The uncertainty in precipitation response, as represented by the ensemble, compares favourably to SEAS5. Whilst SEAS5 achieves superior skill in the tropics for 2-metre temperature and mean sea level pressure (MSLP), GenCast-Persisted achieves higher skill in some areas in higher latitudes, including mountainous areas, with notable improvements for MSLP in particular; this is reflected in a slightly higher correlation with the observed NAO index. Reliability diagrams indicate that GenCast-Persisted has little skill relative to climatology, whilst GenCast-Forced produces forecasts with reliability comparable to SEAS5. These results provide an indication of the potential of MLWP models similar to GenCast for the 'full' seasonal forecasting problem, where the atmospheric model is coupled to ocean, land and cryosphere models.</p>","PeriodicalId":10165,"journal":{"name":"Climate Dynamics","volume":"64 4","pages":"148"},"PeriodicalIF":3.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12992418/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147479878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Anatomy of moist heatwaves in India during the summer monsoon season.","authors":"Akshay Deoras, Andrew G Turner, S Lekshmi, Cathryn E Birch, Ambrogio Volonté, Arathy Menon, Reinhard K H Schiemann, Laura J Wilcox","doi":"10.1007/s00382-025-08023-w","DOIUrl":"10.1007/s00382-025-08023-w","url":null,"abstract":"<p><p>Moist heat impairs the human body's ability to cool through sweat-based evaporative cooling, posing a serious health risk. In India, this risk is especially acute, since the Indian summer monsoon (ISM) brings abundant moisture, and socio-economic conditions significantly increase the exposure and vulnerability to moist heat. However, there is a limited understanding of the characteristics and large-scale drivers of moist heatwaves during the ISM. This study uses the ERA5 reanalysis to analyse moist heatwaves and their relationship with active and break periods of the ISM during 1940-2023. An empirical orthogonal function analysis of daily maximum wet-bulb temperature (T_w) anomalies reveals that the first two principal components (PCs) explain key patterns of variability of moist heatwaves, with PC1 controlling their occurrence and PC2 controlling their spatial extent. Whilst breaks in the monsoon favour moist heatwaves in eastern and peninsular India, active rainfall events, corresponding to phases 5-7 of the Boreal Summer Intraseasonal Oscillation, favour moist heatwaves in northern and northwestern India. Specific humidity plays a larger role than dry-bulb temperature in controlling T_w variability in India. The results of this study reveal important characteristics of moist heatwaves during the ISM and offer potential for developing forecasting tools, which could ultimately benefit stakeholders in India.</p><p><strong>Supplementary information: </strong>The online version contains supplementary material available at 10.1007/s00382-025-08023-w.</p>","PeriodicalId":10165,"journal":{"name":"Climate Dynamics","volume":"64 3","pages":"103"},"PeriodicalIF":3.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12909335/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146218824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Mesoscale Convective Systems in Northeastern North America: identification and evaluation with the convection-permitting version of the Canadian Regional Climate Model.","authors":"Milena Alpizar, Alejandro Di Luca, Philippe Gachon, François Roberge","doi":"10.1007/s00382-026-08102-6","DOIUrl":"10.1007/s00382-026-08102-6","url":null,"abstract":"<p><p>Extreme precipitation events are often associated with mesoscale meteorological phenomena, such as mesoscale convective systems (MCS). Convection-permitting models (CPMs), which operate at high spatial resolution, have enhanced our ability to represent atmospheric processes associated with mesoscale phenomena. This study aims to identify and evaluate MCSs and associated precipitation events in northeastern North America over the 2015-2022 period using various observational and model-based products. A tracking algorithm is used to identify and characterize MCSs in the ERA5 reanalysis, satellite-based (IMERG) data, radar observations (STAGE-IV and MRMS), and two simulations performed with the sixth version of the Canadian Regional Climate Model (CRCM6). These simulations are performed at horizontal grid spacings of 12 km and 2.5 km (CRCM6-12 and CRCM6-2.5, respectively), with the higher-resolution (2.5 km) simulation operating in CPM mode. Radar observations indicate that MCSs occur most frequently from May to September and typically initiate in the early afternoon. The lower horizontal resolution products (IMERG, CRCM6-12, and ERA5) underestimate both the mean occurrence and interannual variability of MCSs compared to the reference dataset STAGE IV-MERGIR, with mean biases of - 17%, - 50%, and - 88% and standard deviations of 23, 17, and 5.8 MCSs per year, respectively (reference standard deviation = 32 systems per year). The CRCM6-2.5 CPM model configuration accurately reproduces key MCS characteristics, including their intra-annual occurrence, size, duration, intensity, diurnal cycle, and their contribution to total and extreme precipitation. Notably, MCSs contribute more to extreme precipitation events than to the total precipitation. The CRCM6-2.5 model significantly improves the representation of convective processes at finer scales compared to lower-resolution products, although it slightly overestimates precipitation in comparison to radar observations.</p><p><strong>Supplementary information: </strong>The online version contains supplementary material available at 10.1007/s00382-026-08102-6.</p>","PeriodicalId":10165,"journal":{"name":"Climate Dynamics","volume":"64 3","pages":"129"},"PeriodicalIF":3.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12953424/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147354026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Key drivers of large scale changes in North Atlantic atmospheric and oceanic circulations and their predictability.","authors":"Buwen Dong, Yevgeny Aksenov, Ioana Colfescu, Ben Harvey, Joël Hirschi, Simon Josey, Hua Lu, Jenny Mecking, Marilena Oltmanns, Scott Osprey, Jon Robson, Stefanie Rynders, Len Shaffrey, Bablu Sinha, Rowan Sutton, Antje Weisheimer","doi":"10.1007/s00382-025-07591-1","DOIUrl":"10.1007/s00382-025-07591-1","url":null,"abstract":"<p><p>Significant changes have occurred during the last few decades across the North Atlantic climate system, including in the atmosphere, ocean, and cryosphere. These large-scale changes play a vital role in shaping regional climate and extreme weather events across the UK and Western Europe. This review synthesizes the characteristics of observed large-scale changes in North Atlantic atmospheric and oceanic circulations during past decades, identifies the drivers and physical processes responsible for these changes, outlines projected changes due to anthropogenic warming, and discusses the predictability of these circulations. On multi-decadal time scales, internal variability, anthropogenic forcings (especially greenhouse gases), and natural forcings (such as solar variability and volcanic eruptions) are identified as key contributors to large-scale variability in North Atlantic atmospheric and oceanic circulations. However, there remain many uncertainties regarding the detailed characteristics of these various influences, and in some cases their relative importance. We therefore conclude that a better understanding of these drivers, and more accurate quantification of their relative roles, are crucial for more reliable decadal predictions and projections of regional climate for the North Atlantic and Europe.</p><p><strong>Supplementary information: </strong>The online version contains supplementary material available at 10.1007/s00382-025-07591-1.</p>","PeriodicalId":10165,"journal":{"name":"Climate Dynamics","volume":"63 2","pages":"113"},"PeriodicalIF":3.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11882673/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143584972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Effects of macro vs. micro initialization and ocean initial-condition memory on the evolution of ensemble spread in the CESM2 large ensemble.","authors":"Clara Deser, Who M Kim, Robert C J Wills, Isla R Simpson, Steve Yeager, Gokhan Danabasoglu, Keith Rodgers, Nan Rosenbloom","doi":"10.1007/s00382-024-07553-z","DOIUrl":"10.1007/s00382-024-07553-z","url":null,"abstract":"<p><p>\"Single Model initial-condition Large Ensembles\" (SMILEs) conducted with Earth system models have transformed our ability to quantify internal climate variability and forced climate change at local and regional scales. An important consideration in their experimental design is the choice of initialization procedure as this influences the duration of initial-condition memory, with implications for interpreting the temporal evolution of both the ensemble-mean and ensemble-spread. Here we leverage the strategic design of the 100-member Community Earth System Model version 2 (CESM2) SMILE to investigate the dependence of ensemble spread on the method of initialization (micro- vs. macro- perturbations) and the effects of ocean initial-condition memory. We find that the evolution of ensemble spread in 10-year low-pass filtered data is relatively insensitive to the method of initialization beyond the second decade, with the notable exception of the tropical Indo-Pacific in the 4th decade, when macro-initialization significantly enhances ensemble spread, possibly as a result of a state-dependent response to major volcanic activity. Initial-condition memory associated with the chosen Atlantic Meridional Overturning Circulation (AMOC) states unfolds in two stages: First, in the North Atlantic lasting 4-5 decades, and subsequently, in the Indo-Pacific sector of the Southern Ocean appearing 35-years after initialization and lasting 3-4 decades. Known AMOC dynamics explain the first stage, but the role of AMOC and the mechanisms responsible for the delayed appearance of initial-condition memory in the Southern Ocean remain to be fully elucidated. Implications and recommendations for the design of future SMILEs are provided.</p><p><strong>Supplementary information: </strong>The online version contains supplementary material available at 10.1007/s00382-024-07553-z.</p>","PeriodicalId":10165,"journal":{"name":"Climate Dynamics","volume":"63 1","pages":"62"},"PeriodicalIF":3.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11668834/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142892075","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"High-resolution climate models improve simulation of monsoon rainfall changes in the Ganga-Brahmaputra-Meghna basin.","authors":"Haider Ali, Hayley J Fowler, Andrew G Turner","doi":"10.1007/s00382-025-07716-6","DOIUrl":"10.1007/s00382-025-07716-6","url":null,"abstract":"<p><p>This study investigates the impact of model resolution on simulating South Asian monsoon rainfall, focusing on the Ganges-Brahmaputra-Meghna (GBM) basin. By comparing high- and low-resolution versions of four CMIP6 HighResMIP model families against reference datasets (MSWEP and ERA5), we emphasize the advantages of high-resolution models in accurately simulating key monsoon characteristics, including annual rainfall, timing, intensity, and duration. Our results show that the high-resolution models align more closely with observed data, outperforming their low-resolution counterparts. Between 1979 and 2014, the high-resolution model ensemble (HR-models) captures key shifts in monsoon timing, such as delayed onset and withdrawal, leading to a slight increase in monsoon duration. In contrast, the low-resolution ensemble (LR-models) showed more pronounced delays in onset. The observational datasets, MSWEP and ERA5, indicate earlier (7 ± 3 days) and later (3 ± 1.2 days) onsets, respectively, with both showing delays in withdrawal, indicating extended monsoon duration. Notably, the increase in monsoon duration is more pronounced in MSWEP observations than in the model simulations, particularly for LR-models. Regarding rainfall trends, the HR-models more accurately reflect observed changes in both total rainfall and extreme rainfall from 1979-2014 compared to LR-models. Future projections (2015-2050) indicate further delays in monsoon onset, with HR-models projecting larger increases in total rainfall and extreme events (up to 4.5%/decade for the 95th percentile of rainfall) compared to LR-models, which show smaller increases and higher variability in total and extreme rainfall. These findings highlight the critical role of model resolution in improving the accuracy of monsoon simulations, with HR models offering more reliable simulations of historical monsoon behaviour and therefore likely more robust projections of future monsoon behavior. These are essential for informed water management and agricultural decision-making over the complex topography of the GBM basin.</p><p><strong>Supplementary information: </strong>The online version contains supplementary material available at 10.1007/s00382-025-07716-6.</p>","PeriodicalId":10165,"journal":{"name":"Climate Dynamics","volume":"63 6","pages":"246"},"PeriodicalIF":3.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12144052/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144246726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Simulated millennial-scale climate variability driven by a convection-advection oscillator.","authors":"Yvan M Romé, Ruza F Ivanovic, Lauren J Gregoire, Didier Swingedouw, Sam Sherriff-Tadano, Reyk Börner","doi":"10.1007/s00382-025-07630-x","DOIUrl":"10.1007/s00382-025-07630-x","url":null,"abstract":"<p><p>The last glacial period, between around 115 and 12 thousand years before present, exhibited strong millennial-scale climate variability. This includes abrupt transitions between cold and warm climates, known as Dansgaard-Oeschger (D-O) cycles. D-O cycles have been linked to switches in dynamical regimes of the Atlantic Overturning Meridional Circulation (AMOC), but the exact mechanisms behind abrupt climate changes and AMOC regime shifts remain poorly understood. This paper introduces the convection-advection oscillator mechanism to explain the millennial-scale oscillations observed in a set of HadCM3 general circulation model simulations forced with snapshots of deglacial meltwater history. The oscillator can be separated into two components acting on different time scales. The fast convection component responds to changes in vertical stratification in the North Atlantic by activating or deactivating deep water formation sites. The slow advection component regulates the accumulation and depletion of salinity in the North Atlantic. This oscillator mechanism is triggered under specific background conditions and freshwater release patterns. The freshwater perturbation causes an instability that triggers a global salt reorganisation, modifying the North Atlantic stratification. For a given forcing pattern, the system oscillates if the salt transport can lead to an alternating reactivation and deactivation of the AMOC. Otherwise, the climate settles in a warm or cold steady state. This mechanism expands existing theories of millennial-scale variability and provides a general framework for understanding abrupt climate change in general circulation models.</p><p><strong>Supplementary information: </strong>The online version contains supplementary material available at 10.1007/s00382-025-07630-x.</p>","PeriodicalId":10165,"journal":{"name":"Climate Dynamics","volume":"63 3","pages":"150"},"PeriodicalIF":3.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11885369/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143584974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"<i>Taxus</i> tree-ring chronologies from southern England reveal western European hydroclimate changes over the past three centuries.","authors":"Tatiana Bebchuk, Andy K Moir, Tito Arosio, Alexander V Kirdyanov, Max C A Torbenson, Paul J Krusic, Toby R Hindson, Heidi Howard, Agata Buchwal, Charles A P Norman, Ulf Büntgen","doi":"10.1007/s00382-025-07601-2","DOIUrl":"10.1007/s00382-025-07601-2","url":null,"abstract":"<p><p>Heatwaves and summer droughts across Europe are likely to intensify under anthropogenic global warming thereby affecting ecological and societal systems. To place modern trends and extremes in the context of past natural variability, annually resolved and absolutely dated climate reconstructions are needed. Here, we present a network of 153 yew (<i>Taxus baccata</i> L.) tree-ring width (TRW) series from 22 sites in southern England that cover the past 310 years. Significant positive correlations were found between TRW chronologies and both April-July precipitation totals (r > 0.7) and July drought indices (r > 0.59) back to 1901 CE (<i>p</i> < 0.05). We used a suite of residual and standard TRW chronologies to reconstruct interannual to multi-decadal spring-summer precipitation and mid-summer drought variability over western Europe, respectively. Our yew hydroclimate reconstructions capture the majority of reported summer droughts and pluvials back to 1710 CE. Clusters of severe drought spells occurred in the second half of the 18th and mid-twentieth century. Our study suggests that the frequency and intensity of recent hydroclimate extremes over western Europe are likely still within the range of past natural variability.</p><p><strong>Supplementary information: </strong>The online version contains supplementary material available at 10.1007/s00382-025-07601-2.</p>","PeriodicalId":10165,"journal":{"name":"Climate Dynamics","volume":"63 2","pages":"108"},"PeriodicalIF":3.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11782366/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143078748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Systematic biases over the equatorial Indian Ocean and their influence on seasonal forecasts of the IOD.","authors":"Marimel Gler, Andrew G Turner, Linda C Hirons, Caroline M Wainwright, Charline Marzin","doi":"10.1007/s00382-025-07794-6","DOIUrl":"https://doi.org/10.1007/s00382-025-07794-6","url":null,"abstract":"<p><p>Accurate seasonal prediction of the Indian Ocean Dipole (IOD) is crucial given its socioeconomic impacts on countries surrounding the Indian Ocean. Using hindcasts from the Met Office Global Seasonal Forecasting System (GloSea6), coupled mean-state biases in the western and eastern equatorial Indian Ocean (WEIO and EEIO) and their impacts on IOD prediction are examined. Results show that GloSea6 exhibits a pronounced cold bias in the EEIO that rapidly develops after the monsoon onset in boreal summer (JJA, July-August) and persists into autumn (SON, September-November). This cold bias is linked to erroneous easterlies and a shallow thermocline, likely associated with the monsoon circulation. The seasonal evolution and relative timing of the precipitation biases, such that they develop through JJA in the EEIO but follow in the WEIO in SON, suggests that the EEIO plays the leading role in the development of coupled feedbacks that lead to the large dipole pattern of coupled biases. Analysis of skill metrics for the IOD shows that GloSea6 achieves a high anomaly correlation coefficient at short lead times, though it tends to overestimate IOD amplitude. This overestimation is larger in the eastern IOD pole than in the western pole and is likely linked to the poor representation of the evolution of the sea surface temperature anomalies in the EEIO during IOD events in SON. This study highlights the crucial role of regional biases, particularly in the EEIO, in shaping IOD variability and demonstrates that addressing such biases in GloSea6 could improve IOD prediction.</p>","PeriodicalId":10165,"journal":{"name":"Climate Dynamics","volume":"63 8","pages":"328"},"PeriodicalIF":3.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12361278/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144944995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}