Atmospheric Research最新文献

{"title":"The outstanding European and Mediterranean heatwave activity during summer 2022","authors":"R.M. Trigo ,&nbsp;D. Barriopedro ,&nbsp;J.M. Garrido-Perez ,&nbsp;A. Simon ,&nbsp;S.M. Plecha ,&nbsp;A. Teles-Machado ,&nbsp;A. Russo ,&nbsp;R. Garcia-Herrera","doi":"10.1016/j.atmosres.2025.108195","DOIUrl":"10.1016/j.atmosres.2025.108195","url":null,"abstract":"<div><div>The European summer of 2022 was exceptionally warm in the historical record (since mid-19th century). We show that it was a record-breaking summer at European scales since at least 1500 due to three large-scale atmospheric heatwaves, all concurring with a prolonged dry period over Europe and an intense marine heatwave over the Mediterranean. We evaluate the role of dynamical (atmospheric circulation) and thermodynamical (regional soil moisture and western Mediterranean sea surface temperatures) drivers. Flow analogues of the June 2022 heatwave are used to reconstruct the expected temperatures under different combinations of these thermodynamical drivers and assess their separate and combined influences on the intensity of the event. Results show a measurable intensification of the heatwave event (of ∼1 °C) by both dry land and warm sea conditions. We also report asymmetric responses to their combined effects: the influence of warm waters on heatwave intensity is larger when accompanied by dry soils than when soils are wet.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"323 ","pages":"Article 108195"},"PeriodicalIF":4.5,"publicationDate":"2025-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143924876","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":"Description of local features associated with wet and dry spell events over Guinea Coast of West Africa","authors":"Oluwaseun W. Ilori ,&nbsp;Debo Z. Adeyewa","doi":"10.1016/j.atmosres.2025.108181","DOIUrl":"10.1016/j.atmosres.2025.108181","url":null,"abstract":"<div><div>Understanding the variability of wet and dry spells in the West African Monsoon (WAM) is essential for improving climate prediction and resource management. Using in situ daily rainfall observations from five stations located within the Guinea Coast having at least 99.5 % data record and pass quality control checks. This study examines the characteristics, atmospheric precursors, and large-scale circulation patterns associated with wet and dry spells during the summer monsoon season (1982–2020). Results reveal significant spatial variability, with Port Harcourt recording the highest wet spell frequency (&gt;5 %), longest duration (53.38 days), and largest rainfall contribution (35.83 %). In contrast, Tabligbo experiences the highest dry spell frequency (10.92 %) and longest duration (76.23 days), contributing only 0.46 % to total monsoonal rainfall due to its location in the Dahomey Gap. Composite analysis of 841 wet and 2188 dry spell days shows a dipole-like structure, where wet spells are linked to enhanced southwesterly winds, cyclonic circulation, and increased moisture transport over the Guinea Coast, while dry spells exhibit anomalous westerlies, moisture divergence, and reduced convection. Lead-lag analysis from five days before to six days after spell onset reveals that wet spells are preceded by easterly anomalies at 850 hPa, followed by strengthening southwesterlies at onset, which peak after the onset before weakening. In contrast, dry spells develop under enhanced westerlies, inhibiting convection before onset, with intensified easterlies exporting moisture offshore from the onset. Vertical wind structures further show that wet spells weaken the African Easterly Jet (AEJ) while strengthening the Tropical Easterly Jet (TEJ), favoring deep convection, whereas dry spells is associated with deeper and stronger moisture depth that suppress convective development. These findings highlight the role of large-scale circulation in modulating regional wet and dry spells, emphasizing the need for long-term coordinated regional observations to improve monsoon forecasting, climate adaptation, and water resource management.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"323 ","pages":"Article 108181"},"PeriodicalIF":4.5,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143917936","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":"Improvements in the prediction of extreme rainfall events with nested high-resolution rapid refresh modelling system over the Indian Himalayan region","authors":"K.B.R.R. Hari Prasad,&nbsp;Ashish Routray,&nbsp;Greeshma M. Mohan,&nbsp;V.S. Prasad","doi":"10.1016/j.atmosres.2025.108191","DOIUrl":"10.1016/j.atmosres.2025.108191","url":null,"abstract":"<div><div>This study investigates the advantages of employing a nested High-Resolution Rapid Refresh (HRRR) model for simulating highly localized heavy rainfall events over the Indian Himalayan region, characterized by a complex terrain. Accurate weather prediction in such a region necessitates a model configuration that resolves the underlying terrain features, incorporates optimal physics combinations, and assimilates the most precise atmospheric state. A nested HRRR system with 5 km and 1 km resolutions was developed, incorporating all available quality observations through an hourly assimilation cycle. Three rainfall episodes from July–August 2023 were analyzed, focusing on spatial rainfall, diurnal variations, dynamic, thermodynamic, and microphysical properties. This nested HRRR system could effectively capture the rainfall intensity and location, as it is better tuned to the realistic atmospheric conditions through frequent assimilation of observations, and thereby, the dynamics and thermodynamics are modified. However, a lead or lag of 1–2 h is observed in the diurnal rainfall variation in both domains. The quantitative model evaluation for rainfall, using various statistical skill scores, demonstrates the better performance of the 1 km domain, emphasizing the impact of higher resolution and frequent updates to initial conditions on the high-impact weather simulation accuracy. The spatial verification with the Contiguous Rain Area (CRA) analysis method reveals that pattern errors dominate over displacement errors and highlights improved spatial accuracy. Overall, the comparison between the 5 km and 1 km domains underscores the importance of high-resolution models, combined with frequent updating of initial conditions, for accurately predicting highly localized, high-impact rainfall events over the Indian Himalayan region.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"323 ","pages":"Article 108191"},"PeriodicalIF":4.5,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143906128","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":"Numeral simulation of impacts of sea land breeze on the formation and dissipation of the Bohai Sea fog","authors":"Lihong Meng ,&nbsp;Lili Liu ,&nbsp;Meng Tian","doi":"10.1016/j.atmosres.2025.108190","DOIUrl":"10.1016/j.atmosres.2025.108190","url":null,"abstract":"<div><div>From 2019 to 2022, there were a total of 34 sea fog events in the Bohai Sea, among which sea land breezes (SLB) occurred 17 times (accounting for 50 %). The duration of fog in the presence of SLB ranged from 24 to 40 h, while fog without SLB lasted between 3 and 7 h. The SLB circulation significantly increased the duration of sea fog. Therefore it's necessity to study the impacts of SLB on fog formation and dissipation of the Bohai Sea. The Weather Research and Forecasting (WRF) model could simulate meteorological elements well, showing good reliability. Sensitivity experiments were carried out using the WRF model on two different types of SLB-fog. The numeral simulation results are showed as follows. Under the influence of land breeze, the vertical cloud liquid water (CLW) content increased 0.016–0.7 g kg⁻¹, the height of the boundary layer reduced 66.7 % ∼ 92.3 %, and temperature inversion layer was formed 0.5 km in the coastal and offshore areas of the Bohai Sea. Thus the sea fog was formed and the coastal fog intensity was enhanced affected by the land breeze. Under the influence of sea breeze, the height of the boundary layer increased 0.5–7 times and the temperature inversion layer disappeared or weakened in coastal cities. The influence of sea breeze on the transportation of CLW content was decreased 0.016–0.358 g kg⁻¹. Under the combined influence of factors such as CLW, temperature inversion, and boundary layer height, the sea breeze caused large-scale dissipation of sea fog in the Bohai Sea or hindered the expansion of the fog area. Numeral simulation of a typical case indicated that the increased CLW content (0.016–0.07 g kg⁻¹) under the influence of land breeze led to the formation of this sea fog. The intensity of the land breeze influenced the size of the fog area. In the near-surface layer of A Platform, the Richardson number (Ri) decreased 0.2–7.2 when affected by the sea breeze, which was conducive to the development of turbulence. The CLW content decreased by up to 0.71 g kg⁻¹. Therefore, the sea fog dissipated over a large area in the Bohai Sea under the influence of sea breeze. These findings suggest that the mesoscale circulation of SLB played an important role when the large-scale meteorological conditions were relatively weak.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"323 ","pages":"Article 108190"},"PeriodicalIF":4.5,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143924275","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 influence of cloud cover on elevation-dependent warming over the Tibetan Plateau from 1984 to 2022","authors":"Yuqing Wu ,&nbsp;Jing Gao","doi":"10.1016/j.atmosres.2025.108188","DOIUrl":"10.1016/j.atmosres.2025.108188","url":null,"abstract":"<div><div>Temperatures on the Tibetan Plateau (TP) have been increasing over the past 50 years, with the warming trend accelerating from +0.16 °C/decade between the mid-1980s and 1990s to +0.36 °C/decade from 2000 to 2022. However, the elevation-dependent warming (EDW) on the TP remains controversial, and the driving mechanisms are poorly understood. Utilizing the ERA5-Land dataset, we investigate EDW patterns across both the Endorheic and Exorheic basins on the TP, focusing on cloud cover characteristics and quantifying the influences of clouds at different levels on EDW through the Random Forest analysis. Our findings reveal distinct EDW patterns, with more pronounced warming occurring at night. Between 2000 and 2022, changes in cloud cover, particularly the increase in high cloud cover at night and middle cloud cover during the day, played a crucial role in modulating temperature trends. The effect of diurnal net cloud radiative forcing (CRF) from 1984 to 2022 is characterized by daytime heating in the western TP, cooling in the eastern TP, and uniform nighttime warming across the TP. The reduction in middle and high cloud cover from 1984 to 2000 was associated with overall warming, while from 2000 to 2022, albedo diminished from middle clouds and increased longwave radiation from high clouds contributed to continued warming, particularly at higher elevations. These findings highlight the role of CRF in amplifying EDW and emphasize the significance of cloud radiative processes in driving regional warming. The study provides valuable insights into the mechanism underlying the accelerated warming on the TP</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"323 ","pages":"Article 108188"},"PeriodicalIF":4.5,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143917934","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":"Numerical simulation of lightning channel reactivation in recoil leader process","authors":"D.I. Iudin ,&nbsp;N.L. Aleksandrov ,&nbsp;A.A. Syssoev ,&nbsp;A.A. Ponomarev","doi":"10.1016/j.atmosres.2025.108187","DOIUrl":"10.1016/j.atmosres.2025.108187","url":null,"abstract":"<div><div>Lightning development involves transient events that produce non-stationary, abrupt changes in lightning structure. The most prominent (and most studied) examples of reactivation of lightning side branches are recoil leaders that are initiated near the tips of previously decayed positive leader channels. This study proposes a numerical model that, among other things, takes into account evolution of channel temperature profile and is aimed at simulation the recoil leader inception. The model is based on the paradigm of reversal point meandering, which is a consequence of the macroscale asymmetry of development of positive and negative lightning poles. Simulation results allow one for the first time to formulate a physically-based and well-founded mechanism of a negative recoil leader initiation. In particular, it is shown that the channel reactivation is provided by the wave of electric field that starts from the branching point and propagates along a previously decayed (but still heated) leader channel when its per-unit-length resistance does not exceed several thousand Ohms per meter. This resistance corresponds to the channel temperature no less than <span><math><mo>∼</mo></math></span>3500 K under equilibrium conditions. It is shown that channel reactivation starts somewhere between the branching point and the previously decayed leader tip, in agreement with observations. Additionally, the plasma chemical aspects of the leader channel reactivation are discussed.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"323 ","pages":"Article 108187"},"PeriodicalIF":4.5,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143924204","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":"Strengths and limitations of the Gálvez-Davison Index in forecasting tropical and subtropical convection over South America","authors":"Augusto G.C. Pereira ,&nbsp;Davidson L. Melo ,&nbsp;Maria Isabel S. Dantas ,&nbsp;Luana O. Barros ,&nbsp;Ádria M. Pereira ,&nbsp;Nedilson S. Ferreira ,&nbsp;Rafaela S. Morais ,&nbsp;Marcelo E. Seluchi","doi":"10.1016/j.atmosres.2025.108184","DOIUrl":"10.1016/j.atmosres.2025.108184","url":null,"abstract":"<div><div>The Gálvez-Davison Index (GDI) was developed to enhance forecasting capabilities of tropical convection. This study evaluates the applicability of the GDI in forecasting deep tropical and subtropical convection, particularly in synoptic scale systems, such as the South Atlantic Convergence Zone (SACZ), and mesoscale phenomena like Mesoscale Convective Complexes (MCC). A hybrid methodology was applied, integrating retrospective and prospective analyses. Initially, a statistical evaluation of the GDI was conducted over the historical period from 1994 to 2024, using convection proxies including omega (vertical velocity) at 500 hPa and net longwave radiation flux (LWR). Subsequently, a brief diagnostic of SACZ and MCC events, which occurred respectively in January 2024 and October 2016, was performed. Based on these events, GDI forecasts derived from the Global Forecast System (GFS) model were compared against satellite observations and ERA5 reanalysis data within the affected regions. Key results demonstrated that, as expected, the GDI performed better in tropical than subtropical regions, showing stronger correlations with convection proxies. Statistical analysis for the SACZ (tropical region) indicated a strong negative correlation between the GDI and omega at 500 hPa (<span><math><mi>R</mi><mo>=</mo><mo>−</mo><mn>0.93</mn></math></span>). Conversely, the correlation between GDI and omega at 500 hPa was weaker for MCC events (subtropical region; <span><math><mi>R</mi><mo>=</mo><mo>−</mo><mn>0.21</mn></math></span>), highlighting a greater influence of dynamic factors in these systems. The GDI successfully identified regions prone to deep convection, particularly within the SACZ domain, where high GDI values coincided with regions of instability and intense precipitation. For MCC events, the index effectively captured convective intensification in subtropical regions. Forecasts of the GDI were reliable in regions where SACZ and MCC systems were active, as validated by satellite imagery. However, high index values were also recorded in areas without actual convection, indicating potential limitations. Comparison between GFS forecasts and ERA5 reanalysis revealed a systematic tendency of the global model to underestimate GDI values across all analyzed regions. The root mean square error (RMSE) varied regionally, reaching a maximum of 6.75 in the oceanic portion of the SACZ. Overall, the GDI proved valuable in forecasting deep convection, capturing both intensification and dissipation stages of convective systems. Its use as a complementary tool is promising, although systematic underestimation by the GFS highlights the need for model improvements. While originally designed for tropical regions, caution is advised when applying the GDI to subtropical areas due to its generally lower performance and weak correlations with convection proxies, particularly in the MCC domain, emphasizing the necessity for methodological refinements.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"323 ","pages":"Article 108184"},"PeriodicalIF":4.5,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143899151","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":"Modeling of poleward-moving tropical cyclones in the northern East China Sea: Intercomparison of WRF physical schemes","authors":"Yi Wu ,&nbsp;Luming Shi ,&nbsp;Bingchen Liang ,&nbsp;Xinying Pan ,&nbsp;Guoxiang Wu ,&nbsp;Zhenlu Wang ,&nbsp;Xuecheng Zhang","doi":"10.1016/j.atmosres.2025.108186","DOIUrl":"10.1016/j.atmosres.2025.108186","url":null,"abstract":"<div><div>Reliable tropical cyclone (TC) modeling and forecasting requires appropriate selection of physical parameterization schemes. This study focusses on the poleward-moving TCs in the northern East China Sea. Numerical experiments are carried out to examine the sensitivity of modeled TC parameters to different combinations of microphysics (MP), planetary boundary layer (PBL), and cumulus convection (CC) schemes. Model performance is evaluated against observations from China Meteorological Administration best-track dataset, satellite retrieved wind fields, and land-based meteorological stations. A composite evaluation metric is introduced to enable cross-variable model assessment and quantify the relative performance of each scheme combination. Results indicate that while MP schemes have a moderate impact on TC's minimum sea level pressure and maximum wind speed, they evidently influence surface wind field reproduction. Model performance across the PBL schemes is generally comparable, except for the University of Washington boundary layer scheme, which demonstrates strong forecasting skill for maximum wind speed but introduces substantial discrepancies in TC track, minimum sea level pressure, and surface wind fields. Moreover, model performance is highly sensitive to the choice of CC scheme. The Tiedtke scheme consistently yields the highest performance score across all datasets, particularly effective in reducing wind field discrepancies. This study underscores the necessity of considering multiple TC parameters and addressing spatial discrepancies in model calibration and performance evaluation. The findings provide insights into optimizing physical scheme combinations for TC modeling in the northern East China Sea, with broader implications for improving extreme weather forecasting. However, their applicability to other regions and TC types remains uncertain. Further investigation is needed to elucidate the physical mechanisms driving scheme-related differences in model performance.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"323 ","pages":"Article 108186"},"PeriodicalIF":4.5,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143911902","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":"Quantifying the drought-flood abrupt alternation events over Wei River Basin: Dynamic evolution characteristics, driving factors and inherent mechanism","authors":"Simin Wang ,&nbsp;Rengui Jiang ,&nbsp;Yong Zhao ,&nbsp;Jiancang Xie ,&nbsp;Shengdong Cheng ,&nbsp;Lingzi Wang ,&nbsp;Xixi Lu","doi":"10.1016/j.atmosres.2025.108185","DOIUrl":"10.1016/j.atmosres.2025.108185","url":null,"abstract":"<div><div>The acceleration of the global water cycle has led to a remarkable increase in the frequency of extreme disasters such as droughts and floods under changing environment. Drought-flood abrupt alternation (DFAA) events, as compound events more destructive than a single flood and drought event, pose severe threats to the sustainable development of ecosystem and society. This study applied the short-cycle drought-flood abrupt transition index (SDFAI) to identify extreme DFAA events in the Wei River Basin (WRB), the largest tributary of the Yellow River Basin of China, extracting their spatiotemporal evolution and non-stationary characteristics. By integrating meteorological factors and teleconnection indices, the drivers and inherent mechanism of DFAA events were ascertained. The results indicate that: (1) Flood-to-drought (FTD) were more severe than drought-to-flood (DTF) during the rainy season. DTF events are projected to dominate after 2016, and prominent mutations in the SDFAI, Min-FTD, and Max-DTF occurring around 1980 and 1995–2001, respectively. (2) Under the main oscillation period, the periods of extreme FTD and DTF events in the WRB were concentrated at 18–30 years and 10–30 years, respectively. (3) Both meteorological factors and teleconnection indices significantly affected the DFAA events. The teleconnection indices mainly associated with the sub-basins were Southern Oscillation Index, Arctic Oscillation, and North Atlantic Oscillation, which exhibited significant resonance periods with extreme FTD and DTF events. The combined contribution of meteorological factors to DFAA events was more susceptible, and the joint effects of teleconnection indices exerted a greater influence on the contribution rate of meteorological factors.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"323 ","pages":"Article 108185"},"PeriodicalIF":4.5,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143887119","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":"A dynamic critical relative humidity based on temperature in cloud parameterization to improve low cloud in an AGCM","authors":"Minghao Wang ,&nbsp;Lanning Wang ,&nbsp;Qizhong Wu ,&nbsp;Huaqiong Cheng ,&nbsp;Xiaoting Sun ,&nbsp;Yaqi Wang ,&nbsp;Qingquan Li","doi":"10.1016/j.atmosres.2025.108183","DOIUrl":"10.1016/j.atmosres.2025.108183","url":null,"abstract":"<div><div>Low clouds are essential to the energy budget and the hydrological cycle, but simulation of low clouds in most AGCMs (atmospheric general circulation models) remains a challenge. The critical relative humidity (RHc) has great significance for cloud parameterization. Based on diagnostic results of CloudSat/CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) satellite data, we propose a fourth-order curve-fitting formula for RHc with respect to temperature (coefficient of determination (<em>R</em>²) = 0.9659). The method was implemented in CAM6 (Community Atmosphere Model, version 6). Compared with the original scheme, the dynamic RHc significantly reduces the negative bias of low clouds over mid- and low-latitude oceans, increases the low cloud fraction by 20 %. Furthermore, the dynamic RHc has an impact on the vertical distribution of cloud amount, significantly increasing the cloud fraction below 700 hPa and reducing it above 400 hPa. The increase in low clouds is accompanied by an increase in liquid water path, which helps reduce the shortwave cloud forcing bias in the subtropics. Besides, the change in cloud fraction caused by the dynamic RHc has an impact on the simulation of precipitation. Finally, the simulation results at 1° and 2° indicate that the method is insensitive to the choice of model resolution.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"323 ","pages":"Article 108183"},"PeriodicalIF":4.5,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143899150","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}