Mike Kendon, Amy Doherty, Dan Hollis, Emily Carlisle, Stephen Packman, Svetlana Jevrejeva, Andrew Matthews, Joanne Williams, Judith Garforth, Tim Sparks
{"title":"State of the UK Climate in 2024","authors":"Mike Kendon, Amy Doherty, Dan Hollis, Emily Carlisle, Stephen Packman, Svetlana Jevrejeva, Andrew Matthews, Joanne Williams, Judith Garforth, Tim Sparks","doi":"10.1002/joc.70010","DOIUrl":"https://doi.org/10.1002/joc.70010","url":null,"abstract":"<p>This report provides a summary of the state of the UK's climate in 2024. It is one of a series of annual reports published in the <i>International Journal of Climatology</i> (IJC) since 2017. It provides the latest assessment of UK climate trends, variations, and extremes based on the most up to date observations and shows what has already happened to our climate.\u0000 <figure>\u0000 <div><picture>\u0000 <source></source></picture><p></p>\u0000 </div>\u0000 </figure></p>","PeriodicalId":13779,"journal":{"name":"International Journal of Climatology","volume":"45 S1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/joc.70010","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144615410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
José Carlos González-Hidalgo, Sergio M. Vicente-Serrano
{"title":"Is There a Precipitation Decline in the Mediterranean Region? An Assessment Based on the Scientific Literatured","authors":"José Carlos González-Hidalgo, Sergio M. Vicente-Serrano","doi":"10.1002/joc.8918","DOIUrl":"https://doi.org/10.1002/joc.8918","url":null,"abstract":"<p>We have compiled studies published since 1980 on annual precipitation trends in the Mediterranean region. The total number of publications reviewed amounts to 337 papers, sourced from various references, focusing exclusively on studies that have analysed observational series, both from meteorological stations and gridded databases. The goal is to provide a comprehensive overview of the available research and results regarding annual precipitation trends, rather than criticising the quality of the data, methods used, or interpretations made. In this context, we present a compilation of papers in which we select original excerpts from the abstract, main text, or conclusions related to annual precipitation trends, summarising each manuscript. We do not focus on seasonal or monthly trends in detail; however, to offer a broader understanding of the extreme spatial and temporal variability of total annual precipitation, we have included in the Supporting Information file a compendium of papers classified by trends at the monthly and seasonal scales. No generalised significant trends are identified across the entire basin. When a significant signal is found, it greatly depends on the length of the period, the specific selected period, and the region. Finally, we discuss some key unresolved issues that need to be addressed to improve future research.</p>","PeriodicalId":13779,"journal":{"name":"International Journal of Climatology","volume":"45 9","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/joc.8918","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144647856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"The Emergence of Near-Permanent Marine Heatwave State in the Tropical Indian Ocean During 2023–2024","authors":"Mohan Soumya","doi":"10.1002/joc.70014","DOIUrl":"https://doi.org/10.1002/joc.70014","url":null,"abstract":"<div>\u0000 \u0000 <p>In 2023/24, global mean surface temperatures exceeded 1.5°C above pre-industrial levels, and the Tropical Indian Ocean (TIO) experienced a record-breaking basin mean anomalous warming of 0.88°C. This unprecedented warming in the TIO is linked to the severe and long-lasting marine heatwave (MHW) events ever recorded in the region, reconciling with the ongoing long-term warming and internal climate variabilities. The MHW events of 2023/24 were primarily centred in the Arabian Sea (AS) and southwestern TIO regions, with mean intensities of 0.73°C and 0.89°C, respectively. The prolonged MHW event developed in the AS region in August 2023 and in the southwestern TIO in July 2023 due to increased oceanic heat gain associated with increased insolation and reduced latent heat loss. The MHW event in the AS was sustained throughout the remainder of the year and the following year by subsurface warming due to the convergence of surface winds in the AS and suppressed cooling by vertical processes. In the southwestern TIO, the event intensified and lasted till December 2024, driven by thermocline warming induced by downwelling Rossby waves, triggered by intensified easterlies associated with an anomalously westward extended cold tongue in the equatorial Indian Ocean, linked to the co-occurrence of strong El Niño and extreme equatorial positive Indian Ocean Dipole (PIOD) events. The extreme warming of the TIO during 2023/24 underscores the ongoing impact of climate change on global ocean surface warming.</p>\u0000 </div>","PeriodicalId":13779,"journal":{"name":"International Journal of Climatology","volume":"45 9","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144647774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yu-Chuan Tien, Mekonnen Gebremichael, Renato Carlos Zambon
{"title":"Evaluating Wet-Seasonal NMME Precipitation Forecasts Over Brazil's Itaipu and Sobradinho Basins","authors":"Yu-Chuan Tien, Mekonnen Gebremichael, Renato Carlos Zambon","doi":"10.1002/joc.8882","DOIUrl":"https://doi.org/10.1002/joc.8882","url":null,"abstract":"<div>\u0000 \u0000 <p>Reliable seasonal precipitation forecasts are vital for managing hydroelectric power plants, particularly in regions with variable climate conditions. This study evaluates the performance of North American Multi-Model Ensemble (NMME) wet-season precipitation forecasts over two hydroelectric basins in Brazil: Itaipu, characterised by a humid subtropical climate, and Sobradinho, located in a semi-arid region. By assessing six NMME models against Integrated Multi-satellitE Retrievals for GPM (IMERG) data and comparing them with statistical models based on atmospheric-oceanic indices, the study identifies significant spatial and model-dependent variations in forecast skill. NMME models struggle with regional anomalies and extreme events, exhibiting systematic biases and limited predictive capability, particularly in drought-prone Sobradinho. In contrast, statistical models leveraging El Niño–Southern Oscillation (ENSO), North Atlantic Oscillation (NAO), Tropical Northern Atlantic Index (TNA), and Tropical Southern Atlantic Index (TSA) indices demonstrate better predictive accuracy. Incorporating select NMME models as predictors improves statistical model performance, highlighting the potential of hybrid modelling approaches. The results emphasise the need for improved parameterisations, localised data integration, and machine learning-driven enhancements to refine seasonal precipitation forecasts for hydropower-critical regions.</p>\u0000 </div>","PeriodicalId":13779,"journal":{"name":"International Journal of Climatology","volume":"45 9","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144647640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Wintertime Trends in Directional Variability and Intensity of Westerly Air Flow in the Polar Jet Region","authors":"Jan Degirmendžić, Michał Marosz","doi":"10.1002/joc.8886","DOIUrl":"https://doi.org/10.1002/joc.8886","url":null,"abstract":"<div>\u0000 \u0000 <p>In the current scientific debate, considerable attention is given to identifying changes in the midlatitude upper-tropospheric wind field that may be associated with Arctic warming. The air flow patterns, such as waviness, blocking and splitting, are among the most frequently studied. In this paper, we analyse changes in both the geometry and intensity of the westerly flow within the polar front jet (PFJ) stream sector. For this purpose, we introduce zonally defined circular statistics. Significant changes in the wind field were detected in the northern flank of the PFJ, close to the Arctic border. In this region, the directional variability of the wind vector calculated in the latitudinal domain increases over a multi-year period, and the latitudinal series of wind vectors becomes increasingly deflected from the purely zonal West-to-East direction. The most significant deflection trend is observed for northerly winds. Wind rose diagrams constructed for the Arctic boundary latitude band complement the picture of these changes, indicating an increased frequency of wind vectors from the N-E-S semicircle during the period 2001–2022 relative to 1980–2000. Alongside changes in flow geometry, the entire sector also experiences PFJ dissipation. The sign of the trends reverses in the southern flank of the PFJ; however, wind directional changes do not reach statistical significance. Within this flank, the PFJ and the subtropical jet (STJ) occur more frequently, which is accompanied by the stabilisation of westerly flow directions. These results support the hypothesis that, in the era of Arctic Amplification, non-zonal or irregular flow patterns are intensifying in the upper-tropospheric polar latitudes.</p>\u0000 </div>","PeriodicalId":13779,"journal":{"name":"International Journal of Climatology","volume":"45 9","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144646955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Vincent Moron, Chalump Oonariya, Chaowat Siwapornchai, John L. McBride
{"title":"Predictability of the Onset of the Rainy Season Across Thailand: Mechanisms and Non-Stationary Behaviour","authors":"Vincent Moron, Chalump Oonariya, Chaowat Siwapornchai, John L. McBride","doi":"10.1002/joc.8884","DOIUrl":"https://doi.org/10.1002/joc.8884","url":null,"abstract":"<p>The onset of the rainy season across 36 stations of Thailand is analysed from 1951 to 2022. The country-scale mean onset occurs in late April with an interannual standard deviation of 11.5 days. It tends to be anomalously late (respectively, early) during decaying warm (respectively, cold) El Niño Southern Oscillation (ENSO) events. Warm ENSO events delay the onset through a deep anticyclonic anomaly over the western North Pacific, intensification of the southern margins of the subtropical westerly jet, sustained easterly low-level anomalies north of the equator and an anomalous anticyclonic circulation combined with in situ cold sea surface temperature (SST) anomalies over the tropical NW Pacific. The predictability of the country-scale onset from February or March SST is large and statistically significant from ~1980, suggesting a high level of confidence for operational forecasts. However, the analysis of 1950–1970s reveals a lack of stationarity to the extent that the SST–onset relationships were then hardly present. Consistently, the spatial coherence of the local-scale onset as well as its predictability and its interannual variability all increase from the start to the end of the period. This non-stationarity seems fundamentally due to a change in the seasonal structure of the decay of warm ENSO events themselves, that is, from ~1980 onwards, they last longer retaining warm equatorial Eastern Pacific SST anomalies through the boreal spring, while the decaying cold ENSO events have undergone no clear change in seasonality. In consequence, in recent decades, the warm ENSO events significantly impact the April–May atmospheric structure over South East Asia, thus delaying the rainy season onset across Thailand. A long-term significant warming SST has occurred over the tropical North West Pacific, which may potentially reduce the impact of warm ENSO events by reducing the in situ anticyclonic anomaly.</p>","PeriodicalId":13779,"journal":{"name":"International Journal of Climatology","volume":"45 9","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/joc.8884","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144646917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Extreme Cold Days and Spells in Northern Europe at 0.5°C–2.0°C Global Warming Levels","authors":"Kimmo Ruosteenoja, Kirsti Jylhä","doi":"10.1002/joc.8875","DOIUrl":"https://doi.org/10.1002/joc.8875","url":null,"abstract":"<p>Projections for cold days and spells in Northern Europe at global warming levels of 0.5°C–2.0°C are derived from bias-corrected output data from 60 runs performed with 25 global climate models. The threshold temperature of a cold day is defined as the 10th percentile of December–February daily mean temperatures at the 0.5°C warming level. A transition from the 0.5°C to the 2.0°C warming level reduces the multi-model mean annual number of cold days by 60%–80%. The total cold day extremity index, consisting of the sum of anomalies below the threshold temperature during the cold season, is reduced even more, by 70%–90%. The largest changes occur in the Kola Peninsula and regions surrounding the White and Baltic Seas. This pattern of change is consistent with the signal-to-noise ratio of the winter mean temperature increase. Nevertheless, inter-model differences in the response are substantial, being largely attributable to the manner in which global warming affects regional winter temperatures. To assess the occurrence of severe cold spells, a 1200-year sample was established by concatenating the bias-corrected output of all 60 model runs. From this extensive sample, it is feasible to robustly determine the return levels of even very extreme cold spells. A severe cold spell occurring once in 10 years on average at the 0.5°C warming level would be experienced approximately once in 30 (70) years at the 1.5°C (2.0°C) level. Correspondingly, a baseline-climate 100-year cold spell would occur at the 2°C warming level less frequently than once in a 1000 years.</p>","PeriodicalId":13779,"journal":{"name":"International Journal of Climatology","volume":"45 9","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/joc.8875","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144646866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Trend Analysis of Extreme Precipitation Indices and Climate Oscillations Over the Yucatan Peninsula for the Period 1980–2010","authors":"Marta Paola Rodríguez-González, Ruth Cerezo-Mota","doi":"10.1002/joc.8885","DOIUrl":"https://doi.org/10.1002/joc.8885","url":null,"abstract":"<p>Using daily precipitation data from 69 weather stations across the Yucatan Peninsula (YP), we analysed trends in extreme precipitation over 30 years at annual and seasonal scales. The analysis included total precipitation (PRCPTOT), intensity indices (R95p, R99p, SDII and Rx1day), frequency indices (R10mm, R20mm and R30mm), and persistence indices (consecutive dry days [CDD] and consecutive wet days [CWD]). Characterising rainfall distribution is crucial, as southeastern Mexico's YP lacks surface water bodies and relies solely on rainfall to recharge its aquifer. Our findings reveal significant spatial and temporal variability in precipitation across the region. Yucatan and northern Campeche exhibit positive trends in total precipitation and extreme rainfall, while Quintana Roo and southern Campeche show negative trends. Notably, Yucatan experiences more intense rainfall during spring and summer, whereas Quintana Roo shows a marked reduction in winter precipitation. In terms of persistence indices, the CDD index shows a significant positive trend, indicating an extension of dry periods in the region, especially in Quintana Roo. Conversely, the CWD index shows a negative trend, highlighting that rainfall is concentrated over fewer days each year. This study also examines the influence of four climate oscillations on YP rainfall. We found that La Niña particularly affects both winter and summer precipitation. Moreover, the positive phase of the North Atlantic Oscillation (NAO) increases the frequency of intense rainfall events in Yucatan during winter. These results highlight the complexity of regional climate dynamics. Additionally, we analysed intensity–duration–frequency (IDF) curves for three tropical cyclones that impacted the YP in 2020. These events caused flooding, infrastructure damage, and crop losses. Some extreme rainfall associated with these cyclones exceeded the 100-year return period, emphasising the urgent need for adaptive strategies to address changing precipitation patterns and mitigate the worst impacts of such events.</p>","PeriodicalId":13779,"journal":{"name":"International Journal of Climatology","volume":"45 9","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/joc.8885","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144646865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Consistency Assessment of CORDEX Multi-Domain Simulations Over the Tibetan Plateau Using REMO","authors":"Ping Li, Xiaorui Niu, Yanjin Mao, Xianchun Chen","doi":"10.1002/joc.8878","DOIUrl":"https://doi.org/10.1002/joc.8878","url":null,"abstract":"<div>\u0000 \u0000 <p>The Tibetan Plateau (TP), often referred to as the Water Tower of Asia and the Third Pole, is undergoing rapid warming and wetting, making it a key focus of contemporary Earth System Science Research. Three Coordinated Regional Downscaling Experiment (CORDEX) domains: CORDEX-EAS-II, CORDEX-CAS-II and CORDEX-SAS-II, overlap over the TP, providing an opportunity to assess the sensitivity of CORDEX simulations to the domain choice in this region. In this study, we analyse the similarities and differences in the latest version of Regional Model (REMO) simulation across the three CORDEX domains at a spatial resolution of 25 km, focusing on climatology and climate extremes. The results show that the choice of simulation domain has minimal impact on REMO's climate and extreme climate simulations over the TP. Three-dimensional indicators reveal that the choice of domains primarily influences the temporal evolution for temperature simulations over the TP, with minimal effects on magnitudes and spatial patterns. For precipitation simulations, the choice of domains has a more pronounced effect on magnitudes than on temporal variation or spatial patterns. Additionally, significant seasonal biases are observed in REMO's simulation of wet days, with negative biases in summer linked to a lower frequency of 1–7 mm precipitation, while positive biases in other seasons are associated with an overestimation of moderate-to-heavy rainfall frequencies.</p>\u0000 </div>","PeriodicalId":13779,"journal":{"name":"International Journal of Climatology","volume":"45 9","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144647756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Spring Rapid Temperature Variability in Southern China: Characteristics, Decadal Trend and Associated Climate Impacts on Crop Yield","authors":"Xianke Yang, Yixuan Zhang, Haosu Tang, Ping Huang, Xiaoxia Ling, Shaobing Peng, Dongliang Xiong","doi":"10.1002/joc.8880","DOIUrl":"https://doi.org/10.1002/joc.8880","url":null,"abstract":"<div>\u0000 \u0000 <p>Climate-related risks are shaped not only by changes in mean temperatures, but also by temperature variability, which raises the likelihood of extreme weather events with profound impacts on society and ecosystems. Previous studies have documented contrasting seasonal trend differences in summer and winter temperature variability across most land areas. However, spring—a phenologically sensitive season for agricultural systems—has received limited attention for its temperature variability. Focusing on the major rice-growing regions in southern China, this study employs three indices—daily temperature standard deviation (STD), day-to-day temperature variability (DTD) and rapid cooling events (RCE)—to analyse the decadal trends and causes of spring temperature variability and assess its climate effects on rice yield anomalies. Our results reveal decadal trends in the spatial distribution of temperature variability, with increasing frequency and intensity in the Yangtze River Basin and Yunnan Province, and a decreasing trend across much of South China, closely following regional climatological patterns. Overall, the frequency and intensity of RCE trend exhibit a “strong gets weaker, weak gets stronger” pattern, likely linked to increased STD trends caused by spatial non-uniformity of warming. Through a multiple regression statistical model employing dominance analysis, we find that climate factors, including both mean climate and climate variability, explained 19%–45% of the variance in provincial rice yield anomalies, with up to 13% of the explained variance attributable to spring climate factors related to temperature variability. This study underscores the critical role of spring temperature variability in climate resilience, highlights the urgent need to enhance the adaptability of agricultural systems to extreme climate events.</p>\u0000 </div>","PeriodicalId":13779,"journal":{"name":"International Journal of Climatology","volume":"45 9","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144647854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}