Atmospheric Research最新文献

{"title":"Enhancing summer atmospheric water cycle simulations in the Three-River Headwaters Region via dynamical downscaling","authors":"Xuan Liu ,&nbsp;Mingxiang Yang ,&nbsp;Tinghai Ou ,&nbsp;Hui-Wen Lai ,&nbsp;Fan Wen ,&nbsp;Ningpeng Dong ,&nbsp;Hao Wang ,&nbsp;Deliang Chen","doi":"10.1016/j.atmosres.2024.107810","DOIUrl":"10.1016/j.atmosres.2024.107810","url":null,"abstract":"<div><div>Characterizing and understanding the evolving water cycle in the Three-River Headwaters (TRH) region of the Tibetan Plateau, where data scarcity poses significant challenges to climate and atmospheric water cycle research, heavily depends on model simulations. However, advanced global climate models and reanalysis datasets frequently overestimate precipitation. To address this, we employ high-resolution (9 km) regional climate simulations (WRF9km) to examine atmospheric water cycle variables in the TRH region, comparing them with in-situ observations and ERA5 reanalysis. Our study demonstrates that WRF9km substantially reduces the overestimation of summer precipitation (by 24.0 %) and evapotranspiration (by 52.7 %) compared to ERA5, thereby improving its alignment with observational data. The reduced biases in precipitation are attributed to diminished moisture influx from the southern boundary and local evapotranspiration, coupled with increased moisture export from the eastern boundary. Summer precipitation recycling (PR) accounts for approximately 20 % of total precipitation in the TRH region. Despite divergent trends in PR between a water accounting model (WAM) and a bulk method, our findings support the reliability of WAM, indicating a slight decrease in summer PR (−0.4 %/10a for ERA5 and − 0.6 %/10a for WRF9km). While WRF9km accurately captures the spatial pattern of summer PR, ERA5 appears to overestimate it, likely due to biases in evapotranspiration and moisture inflow. In conclusion, WRF9km provides a more accurate representation of the atmospheric water cycle in the TRH region.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"314 ","pages":"Article 107810"},"PeriodicalIF":4.5,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142723844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The significant influence of the sea surface temperature anomalies over North Atlantic and the Maritime Continent on maize yield in Northeast China","authors":"Sichao Yan ,&nbsp;Huopo Chen","doi":"10.1016/j.atmosres.2024.107806","DOIUrl":"10.1016/j.atmosres.2024.107806","url":null,"abstract":"<div><div>Northeastern China (NEC) is the largest grain base in China. Improving understanding of the effect of climate change on grain production over NEC is conducive to providing immediate response strategies for grain production. In this study, the relationships of the maize production with the dry state during the different maize growth stage have been investigated using the year-to-year increment method. Results showed that the severe drought that occurred from the jointing to maturity period have exerted severe effects on the maize growth. Further analysis indicated that the sea surface temperature (SST) anomalies over North Atlantic and Maritime Continent in later spring are the important factors affecting the summer droughts over NEC. The late spring SST anomaly over North Atlantic can excite the Rossby waves from the western North Atlantic and propagate eastward to NEC. The snow anomaly over western Siberia in late spring and the soil moisture anomaly over NEC in summer are key factors linking the SST anomaly to drought over the NEC. On the other hand, the Maritime Continent SST anomaly in late spring can modulate the activity of the East Asian jet stream via the East Asia-Pacific (EAP) teleconnection, which can provide the favorable conditions for the soil moisture reduction over NEC. Eventually, a predictive model for maize yield over NEC is successfully developed by using the predictive indices of the North Atlantic and the Maritime Continental SST during late spring. Both the cross-validation and independent sample tests show that the calibrated prediction model is robust and exhibits high skill in predicting maize yield over NEC.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"314 ","pages":"Article 107806"},"PeriodicalIF":4.5,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142701211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Contrasting northward and southward propagations of intraseasonal precipitation under the southern China summer rainfall pattern","authors":"Hao Pan,&nbsp;Hong-Li Ren,&nbsp;Jieru Ma,&nbsp;Yuwen Wang","doi":"10.1016/j.atmosres.2024.107808","DOIUrl":"10.1016/j.atmosres.2024.107808","url":null,"abstract":"<div><div>Propagations of intraseasonal precipitation are essential for subseasonal prediction of East Asian summer rainbelt. In this study, under the background of the southern China summer rainfall pattern (SCSRP), the intraseasonal northward and southward propagation types are first identified and then their propagation characteristics and influencing factors on the 20–90-day intraseasonal timescale are deeply examined. Results show that the northward propagation type, being primary during the SCSRP in its most cases, features robust northward propagation of anomalous signals in the low-level southwesterly wind, outgoing longwave radiation, and 500-hPa geopotential height (Z500) towards the Yangtze River basin. For the southward propagation type, anomalous signals of Z500 with low-level northeasterly wind mainly exhibit a clear southward propagation from the northwest continental area, towards the precipitation anomaly center in southern China. We further reveal that the northward propagation type of intraseasonal precipitation is dynamically related to the first mode of boreal summer intraseasonal oscillation (BSISO) that exhibits significant precipitation anomalies over the southern China in its Phases 5 and 8, and to the intraseasonal oscillation in the East Asia-Western North Pacific (EAWNP ISO) that shows significant precipitation anomalies in its Phases 3 and 5. In contrast, the southward propagation type is primarily influenced by the wave trains of anomalous circulation over mid-to-high latitudes.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"314 ","pages":"Article 107808"},"PeriodicalIF":4.5,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142684198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"“Colder North Eurasia, warmer North America” pattern in December 2023 and its blocking precursor","authors":"Xinping Xu ,&nbsp;Shengping He ,&nbsp;Huijun Wang ,&nbsp;Jiapeng Miao","doi":"10.1016/j.atmosres.2024.107807","DOIUrl":"10.1016/j.atmosres.2024.107807","url":null,"abstract":"<div><div>A seesawing temperature pattern occurred over northern mid-latitudes in December 2023, with cold anomalies over northern parts of Eurasia and warm conditions over North America. The recurrent dipole temperature pattern in boreal winter has been revealed to be associated with concurrent changes in atmospheric variability (e.g., Siberian high and Alaska ridge) and boundary forcing (e.g., Arctic sea ice and North Atlantic sea surface temperature), whereas its precursor features remain less clear. Based on reanalysis data and two sets of coupled simulations, this study revealed that strong blocking activity over the Greenland-Eurasia sector in November was an important precursor to the remarkable “colder North Eurasia, warmer North America” pattern in December 2023. Increased tropospheric blocking frequency in November favored vertically propagating planetary waves to weaken the stratospheric polar vortex. The stratospheric response that persisted into December was characterized as the shift of polar vortex towards Eurasia and away from North America, linked to the enhanced zonal wavenumber-1 planetary waves. Downward propagation of the amplified wavenumber-1 component into the troposphere in December contributed to stronger continental high pressure over Eurasia and weaker ridge over Alaska, causing the “colder North Eurasia, warmer North America” pattern. High consistency between the results of observations and two sets of numerical simulations confirms the critical role of preceding tropospheric blocking, which is valuable for sub-seasonal prediction of the dipole temperature pattern across northern mid-latitudes.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"314 ","pages":"Article 107807"},"PeriodicalIF":4.5,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142684232","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":"Spatio-temporal patterns of compound dry-hot extremes in China","authors":"Chensi Zhou ,&nbsp;Guojie Wang ,&nbsp;Huiyan Jiang ,&nbsp;Shijie Li ,&nbsp;Xiao Shi ,&nbsp;Yifan Hu ,&nbsp;Pedro Cabral","doi":"10.1016/j.atmosres.2024.107795","DOIUrl":"10.1016/j.atmosres.2024.107795","url":null,"abstract":"<div><div>Under global warming, the simultaneous occurrence of drought and high temperature is raising growing concerns due to their detrimental impacts on ecosystems, water resources, and food security. Extensive studies have evaluated different characteristics (e.g., spatial extent and frequency) of such compound extremes using percentile-threshold methods based on historical records and climate model projections. Nevertheless, quantitative assessments of projected changes in compound dry-hot extremes based on the daily-scale compound dry-hot index which is constructed by copula theory and the latest CMIP6 downscaled projection outputs are rather rare. Based on the NASA Earth Exchange Global Daily Downscaled Projections (NEX-GDDP-CMIP6), the study first calculated the daily Standardized Compound Dry and Hot Index (SCDHI) by combining Standardized Antecedent Precipitation Evapotranspiration Index (SAPEI) and Standardized Temperature Index (STI) to identify compound dry-hot extremes while exploring its constraints for an accurate evaluation of its spatiotemporal evolution in China from 1961 to 2100. In this study, a reasonable threshold is determined to reduce some dry but no hot (hot but no dry) condition incorrectly identified as compound dry-hot condition. In terms of temporal variation, the study shows that all characteristics (i.e., occurrence, intensity, and area) are projected to increase over the next 80 years under the four Shared Socioeconomic Pathway scenarios (SSP1–2.6, SSP2–4.5, SSP3–7.0, SSP5–8.5). Particularly in the last 30 years of the 21st century, these features escalate significantly and rapidly, and the higher the emission scenario, the greater the escalation. From a spatial distribution perspective, we find that a more frequent occurrence of compound dry-hot days across China under the future SSPs compared to 1961–2020, with more so in Xinjiang, Tibet, Qinghai, Hainan, and Southwest China. These findings emphasize that policy makers should take relevant and timely measures to reduce social and economic losses caused by intensified projected compound dry-hot extremes.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"314 ","pages":"Article 107795"},"PeriodicalIF":4.5,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142684199","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"December 2022 north American bomb cyclone: Insights from perturbation energetics","authors":"Emerson DeLarme ,&nbsp;Jianping Li ,&nbsp;Hongyuan Zhao ,&nbsp;Yuan Liu ,&nbsp;Ruipeng Sun","doi":"10.1016/j.atmosres.2024.107794","DOIUrl":"10.1016/j.atmosres.2024.107794","url":null,"abstract":"<div><div>Explosive cyclone development has been shown to be a positive feedback process, however what causes this to end is an open question. We employ the perturbation potential energy (PPE) framework to investigate the evolution of the December 2022 North American bomb cyclone (NABC) as a case study. A layer with negative PPE anomaly separates the positive PPE anomaly generated by the December 2022 NABC from a positive PPE anomaly near the tropopause during the development phase. This layer of negative PPE anomalies acts as a barrier such that positive PV anomalies cannot pass through. At the start of the decay phase, this barrier breaks, allowing stratospheric intrusion. Here we propose a mechanism where the negative upper pole of the vertical PV dipole caused by atmospheric latent heating (the lower, positive pole is involved in the positive feedback loop of development) triggers a cascade of events, where this PV anomaly causes tropopause deformation, which causes circulation anomalies, which causes enhanced energy conversion, which causes the negative PPE anomaly barrier to break, allowing a positive PV anomaly airmass to descend (indicative of stratospheric intrusion) through the break, leading to the suppression of further atmospheric latent heat release, and therefore ending the development phase of this bomb cyclone, despite the non-depletion of moisture in the vicinity of the December 2022 NABC. While this process is shown for a specific case study, the improved understanding of the life cycle of explosive cyclones has the potential to improve forecasting of explosive cyclones in the future.</div></div><div><h3>Plain language summary</h3><div>Bomb cyclones over land can have large social and economic consequences. Bomb cyclones are known to get stronger in part due to a cycle involving the increased potential vorticity below a level where water vapor condenses. The reasons that explosive cyclones stop developing has yet to be determined, and finding this mechanism could improve forecasts and therefore improve preparedness. In this paper we conduct a case study on a bomb cyclone that happened over North America in late December 2022 using some traditional approaches combined with a newer energetics method focusing on the local perturbations of the potential and kinetic energies. We find that this bomb cyclone stopped getting stronger, not because it ran out of water, but because of a chain of events starting from the decreased potential vorticity above the same condensation. Further research is needed to see if this process exists in other bomb cyclones, and if it can be turned into a predictive tool for forecasting.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"314 ","pages":"Article 107794"},"PeriodicalIF":4.5,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142684200","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamics of a severe summer Shamal wind and its induced dust storm in the Middle East: A diagnostic study based on numerical simulation","authors":"Abbas Mofidi ,&nbsp;Azar Zarrin ,&nbsp;Samira Hassani ,&nbsp;Mohsen Soltani","doi":"10.1016/j.atmosres.2024.107800","DOIUrl":"10.1016/j.atmosres.2024.107800","url":null,"abstract":"<div><div>This study investigates the formation and dynamics of the Summer Shamal Wind (SSW) and its associated dust storms over the Middle East. A regional climate model, RegCM4, coupled with a dust module, is employed to simulate a severe dust storm event on June 12, 2006. To gain deeper insights, a novel dynamical mechanism is proposed. This mechanism highlights the crucial role of both mechanical and thermal forcing in shaping the regional atmospheric circulation. The vertical heat advection from the Zagros Mountains (ZAG), combined with the mechanical forcing from a shallow incident flow originating from the Turkmenistan anticyclone, triggers upward motion over the ZAG. This synergistic effect leads to the development of a mid-tropospheric anticyclone over the ZAG, which, in turn, induces a westward-propagating Rossby wave. The downward motion and descending air associated with this wave over Mesopotamia establish a terrain-induced local circulation. Consequently, the SSW emerges within a shallow layer at the null-vorticity zone of a coupling-pressure pattern formed by the Arabian anticyclone and the Zagros trough, which is itself a product of the terrain-induced circulation. The study concludes that the intensification and southward movement of the Turkmenistan anticyclone play a pivotal role in the formation of severe SSWs and subsequent dust storms over the Middle East.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"314 ","pages":"Article 107800"},"PeriodicalIF":4.5,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142701212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced understanding of warming and humidifying on ground heat flux in the Tibetan Plateau Hinterland","authors":"Jianan He ,&nbsp;Weiqiang Ma ,&nbsp;Zhipeng Xie ,&nbsp;Xi Qi ,&nbsp;Longtengfei Ma ,&nbsp;Weiyao Ma ,&nbsp;Xiangyu Guo ,&nbsp;Yaoming Ma","doi":"10.1016/j.atmosres.2024.107799","DOIUrl":"10.1016/j.atmosres.2024.107799","url":null,"abstract":"<div><div>The land surface layer is an important interface between the ground and atmosphere, and cross-surface ground heat flux (G₀) has a significant impact on land surface energy processes and associated cycles. Therefore, understanding dynamics in G₀ is critical for predicting climate changes and developing adaptation strategies. However, the harsh environment and geographic barriers of the Tibetan Plateau have led to a significant lack of observations and soil samples, ultimately limiting the accuracy and application of G₀ calculations. Here we investigated the changes in G₀ at the BJ station, a typical seasonally frozen ground region of the Tibetan Plateau, through soil sampling and long-term in-situ observations. We used the calorimetric method to minimize reliance on model assumptions, aiming to achieve consistent and broadly applicable results. During the freezing-to-thawing and thawing-to-freezing stages, daytime G₀ decreased while nighttime G₀ increased. Conversely, daytime G₀ increased while nighttime G₀ decreased in the completely thawed and completely frozen stages. In moist conditions, more energy was directed toward soil moisture evaporation and vegetation transpiration, whereas in dry conditions, net radiation primarily increased soil temperature, enhancing G₀. Our results revealed the dynamic changes in G₀ across different environmental conditions and their impact on land-atmosphere interactions, and that climate warming and humidifying will diminish the regulatory capacity of G₀. This study highlights the essential requirement for accurate G₀ to predict future climate changes accurately, emphasizing its importance for researchers focusing on land-atmosphere feedback mechanisms and climate modeling.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"314 ","pages":"Article 107799"},"PeriodicalIF":4.5,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142701310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sensitivity of localized heavy rainfall in Northern Japan to WRF physics parameterization schemes","authors":"Yusuke Hiraga,&nbsp;Ryotaro Tahara","doi":"10.1016/j.atmosres.2024.107802","DOIUrl":"10.1016/j.atmosres.2024.107802","url":null,"abstract":"<div><div>This study examined the sensitivity of cloud microphysics and planetary boundary layer (PBL) parameterization in the simulation of localized heavy rainfall in northern Japan such as the August 2022 event. Accurate simulation/forecast of such quasi-stationary line-shaped mesoscale convective systems is a pressing issue for the region. The sensitivities of 17 different cloud microphysics parameterization schemes, including single and double moments, and eight different PBL schemes, including nonlocal and local closure schemes, were investigated. Overall, the simulated heavy rainfall in August 2022 was notably sensitive to the microphysics and PBL schemes. Among the microphysical parameterization comparisons, the Goddard and Eta (Ferrier) schemes exhibited superior performance in simulating the magnitude and spatial distribution of heavy rainfall events, evaluated using various precipitation statistics and object-based measure (Structure-Amplitude-Location (SAL) method). Considering the sensitivity of the PBL schemes, the combination of the Goddard microphysics scheme and the Grenier–Bretherton–McCaa PBL scheme performed the best in the 48-h basin-average precipitation depth and spatial distribution RMSE. Ensemble correlation analysis revealed that a better representation of the strong water vapor flux convergence was the key to simulating localized heavy rainfall. The optimal combination of physical schemes reasonably simulated the July 2020 and July 2023 heavy rainfall events in the Tohoku region, suggesting their potential for future RCM studies in the region.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"314 ","pages":"Article 107802"},"PeriodicalIF":4.5,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142700360","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":"Interdecadal opposite variation of December–January blocking days between the eastern North Atlantic and Ural region around 2008","authors":"Yifan Xu ,&nbsp;Ke Fan ,&nbsp;Shengping He","doi":"10.1016/j.atmosres.2024.107805","DOIUrl":"10.1016/j.atmosres.2024.107805","url":null,"abstract":"<div><div>Based on observational datasets during 1980–2021 and the simulations from the PAMIP (Polar Amplification Model Intercomparison Project), this paper indicates that the eastern North Atlantic–Ural blocking days in December–January is characterized by a zonal dipole pattern which undergoes an interdecadal variation around 2008. Specifically, the blocking days in Ural (eastern North Atlantic–western Europe) regions increases (decreases) after 2008. Further research shows that the variation in the blocking days dipole (BDD) pattern is closely associated with the changes in the simultaneous background atmospheric circulation field including westerly winds, vertical shear of zonal winds, and meridional potential vorticity gradient over the eastern North Atlantic–Urals region. Moreover, after 2008, the positive North Atlantic Oscillation–like phase intensifies, a quasi-stationary eastward-propagating Rossby wave from the North Atlantic is excited, and a quasi-barotropic “−, +, −” tripole circulation anomaly in the eastern North Atlantic–Central Siberia is formed in the mid–upper troposphere. It is also found that, since 2008, there is a remarkable negative correlation between the Barents–Kara sea-ice concentration (SIC) and the BDD. After 2008, the rapid decrease in Barents–Kara SIC, dominated by newly formed SIC, is conducive to an increased local upward surface turbulent heat flux, further exciting Rossby waves and favoring the tripole circulation anomaly. Additionally, the atmospheric internal dynamical processes excited by the tripole circulation anomaly have positive feedback effects on it, contributing to strengthening (weakening) of the local background circulation field in the eastern North Atlantic–western Europe (Urals) region, thereby causing the blocking days to decrease (increase). The responses of the main physical processes to the Arctic sea ice reduction in the PAMIP models are roughly in agreement with the observations.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"314 ","pages":"Article 107805"},"PeriodicalIF":4.5,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142684196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}