Atmospheric Research最新文献

{"title":"Observational force analysis and anisotropic characteristics of tropical cyclone sea surface wind fields over Chinese offshore areas","authors":"DanChen Yan ,&nbsp;TianYu Zhang ,&nbsp;LengJian Chen ,&nbsp;Cheng Chi ,&nbsp;JianYang ,&nbsp;ZiJing Ou","doi":"10.1016/j.atmosres.2025.107986","DOIUrl":"10.1016/j.atmosres.2025.107986","url":null,"abstract":"<div><div>In this paper, based on the observation data of sea surface buoys, 17 tropical cyclones (TCs) occurring in the East China Sea and South China Sea from 2017 to 2021 are synthesized to conduct a force analysis in a two-dimensional radial momentum equation. The analysis evaluates the magnitude, equilibrium, proportional relationships, and spatial distribution features of each force, leading to clarified universal laws. The findings reveal a pronounced radial variability feature in the mean TC sea surface structure. Notably, the regions where the changes are most dramatic are located approximately 80 km from the mean TC center and particularly at 20–40 km. Within an overall range of 0–400 km, the cumulative contributions of each force from high to low are the pressure gradient force, friction term, centrifugal force, Coriolis force and acceleration force. In addition, obvious anisotropic features are also observed. The four orientations can be arranged according to force strength as the right region (240–300°), left region (60–120°), rear region (150–210°) and front region (0–30° and 330–360°). The pronounced pressure gradient force is extremely unstable within the 250 km range of the right (240–300°) and 200 km range of the left (60–120°) regions of the mean TC. The sensitivity of the centrifugal force to radial changes surpasses that of azimuthal changes, and significant variations are concentrated within a radial distance of 50 km. For the Coriolis force, noticeable anisotropic features are evident within the 150 km radius of the 210–330° sector. Additionally, a comparison of the observed radial pressure profile with empirical pressure models was conducted. We found that B parameter values between 0.7 and 1.0 are optimal for our observational cases. Selecting an appropriate environmental pressure can bring the empirical model closer to the observed data. This study establishes a realistic foundation for enhancing existing sea surface parametric wind models of TCs and developing novel approaches, thereby ultimately improving the numerical calculation accuracy for storm surges and other air–sea interactions.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"318 ","pages":"Article 107986"},"PeriodicalIF":4.5,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143509590","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":"A new way to obtain the weighted mean temperature (Tm): Using the Geostationary Interferometric Infrared Sounder (GIIRS) equipped on FengYun Satellite","authors":"Fei Yang ,&nbsp;Yue Sun ,&nbsp;Mingjia Liu ,&nbsp;Shiji Song ,&nbsp;Weicong Chen ,&nbsp;Zhicai Li ,&nbsp;Lei Wang","doi":"10.1016/j.atmosres.2025.107997","DOIUrl":"10.1016/j.atmosres.2025.107997","url":null,"abstract":"<div><div>Atmospheric weighted mean temperature (Tm) is an important parameter in the Global Navigation Satellite System (GNSS) meteorology, essential for retrieving precipitable water vapor (PWV). The FengYun-4 satellite (FY-4) carries Geostationary Interferometric Infrared Sounder (GIIRS), which realizes the transition from two-dimensional to three-dimensional detection of the vertical structure of the atmosphere in geostationary orbit, providing a more convenient and accurate data source for the inversion of Tm. The study presents a novel approach for deriving the Tm based on the GIIRS products of FengYun-4A satellite (FY-4A) and FengYun-4B satellite (FY-4B). The Tm calculated from the radiosonde data is utilized as reference to assess the performance of FY-4A and FY-4B, which demonstrates that the GIIRS equipped on FY-4 can provide a new way to obtain the Tm. The numerical results show that the mean absolute error (MAE) and root mean square error (RMSE) are 1.65/ 2.06 K and 1.38/ 1.73 K for FY-4A and FY-4B, respectively. The different performance of FY-4A and FY-4B on Tm are also observed from the analysis of the geographical distribution, seasons and epochs. Specifically, the RMSE distribution of FY-4A at different stations ranges from 1.08 to 3.47 K, while the distribution of FY-4B is more concentrated between 1.37 and 2.70 K. The accuracy of FY-4 A deteriorates as increasing latitude, while the phenomenon is not obvious for FY-4B. Moreover, FY-4 A performs slightly better at UTC 0:00 than at UTC 12:00, while FY-4B has a slightly better performance in autumn than in other seasons.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"318 ","pages":"Article 107997"},"PeriodicalIF":4.5,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465408","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 role of Madden-Julian Oscillation, Westerly Wind Bursts, and Kelvin Waves in triggering extreme rainfall through Mesoscale Convective Systems: A case study of West Sumatra, March 7–8, 2024","authors":"Elfira Saufina ,&nbsp;Trismidianto ,&nbsp;Didi Satiadi ,&nbsp;Wendi Harjupa ,&nbsp;Risyanto ,&nbsp;Anis Purwaningsih ,&nbsp;Ibnu Fathrio ,&nbsp;Alfan Sukmana Praja ,&nbsp;Ina Juaeni ,&nbsp;Adi Witono ,&nbsp;Fahmi Rahmatia ,&nbsp;Ridho Pratama ,&nbsp;Muhaji Sahnita Putri ,&nbsp;Putri Wulandari","doi":"10.1016/j.atmosres.2025.107993","DOIUrl":"10.1016/j.atmosres.2025.107993","url":null,"abstract":"<div><div>The West Sumatra region experienced devastating floods and landslides due to intense rainfall on March 7–8, 2024, with precipitation ranging from 200 to 394 mm/day exceeding the extreme rainfall threshold of 150 mm/day. We investigated the atmospheric dynamics to understand the mechanisms underlying this event. We used satellite data from Himawari-8 and Global Satellite Mapping of Precipitation (GSMaP) and ground-based observations to analyze cloud development and rainfall distribution. Wind velocity, Integrated Water Vapor Transport (IVT), Convective Available Potential Energy (CAPE), Convective Inhibition (CINH), K-Index, Vertically Integrated Moisture Flux Convergence (VIMFC), and Outgoing Longwave Radiation (OLR) from ERA5 reanalysis datasets are used to analyze convective instability and identify Equatorial waves. The Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model was employed to assess moisture transport. Our findings indicate that extreme rainfall was driven by the Mesoscale Convective System (MCS), as confirmed by cloud observations from Himawari-8. Further analysis revealed that moisture convergence, intensified by a Westerly Wind Burst (WWB) from the Indian Ocean, interacted with local topography and atmospheric circulations over West Sumatra. This interaction was associated with an active Madden-Julian Oscillation (MJO) in Phase 4, strengthening the westerly winds, transporting moisture and fueling convection. Before the event, MJO activity in Phase 3 over the Indian Ocean coincided with an atmospheric Kelvin wave, intensifying low-level convergence, enriching the Indian Ocean region with moisture, and transporting it to West Sumatra via the WWB. The interplay of the MJO, WWB, and Kelvin waves likely amplified the event. This study provides insights into the atmospheric processes behind this event and highlights their importance in developing early warning systems for future events.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"318 ","pages":"Article 107993"},"PeriodicalIF":4.5,"publicationDate":"2025-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143444594","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":"Sources and light absorption of brown carbon in urban areas of the Sichuan Basin, China: Contribution from biomass burning and secondary formation","authors":"Chao Peng ,&nbsp;Mi Tian ,&nbsp;Guangming Shi ,&nbsp;Shumin Zhang ,&nbsp;Xin Long ,&nbsp;Hanxiong Che ,&nbsp;Jie Zhong ,&nbsp;Xiangyu You ,&nbsp;Zhier Bao ,&nbsp;Fumo Yang ,&nbsp;Xin Qi ,&nbsp;Chongzhi Zhai ,&nbsp;Yang Chen","doi":"10.1016/j.atmosres.2025.107992","DOIUrl":"10.1016/j.atmosres.2025.107992","url":null,"abstract":"<div><div>The optical properties of brown carbon (BrC) and their correlation with chemical characteristics remained inadequately understood in different regions worldwide. This study investigated the correlations and estimated the subsequent radiative effects using real-time measurements during wintertime in the Sichuan Basin, China. The average light absorption of BrC (Abs_BrC) at 370 nm constituted 35.5 ± 8.2 % of total absorption, significantly higher than those at 470 nm (20.9 ± 4.3 %), 590 nm (14.0 ± 2.5 %), and 660 nm (7.7 ± 2.1 %) (<em>p</em> &lt; 0.001). The contributions of various organic aerosol (OA) sources to Abs_BrC varied by wavelength, with biomass-burning OA (BBOA) and semi-volatile oxygenated OA (SVOOA) exhibiting the higher Abs (14.4 Mm⁻¹ and 13.5 Mm⁻¹), absorption Ångström exponents (AAE) (4.81 and 4.35), and contributions to Abs_BrC (24.4 % and 22.8 %). Additionally, secondary BrC likely formed from BBOA through aqueous-phase reactions during winter. The transport of BBOA and SVOOA from northern regions (i.e., Guang'an in Sichuan and Hechuan in Chongqing) significantly contributed to elevated Abs_370,BrC levels. The mean simple forcing efficiency for BrC (SFE_BrC) was 60.5 W g⁻¹, accounting for 14 % of SFE_BC in the 370–880 nm range during winter. Overall, this study enhanced the understanding of Abs_BrC and its evolution with sources, providing a more accurate assessment of its radiative effects, and emphasized the importance of biomass burning emissions.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"318 ","pages":"Article 107992"},"PeriodicalIF":4.5,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143437585","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 mixed layer depth along the course of incoming air masses to the transport of PM10 components at three rural sampling sites in Spain","authors":"Konstantinos Dimitriou","doi":"10.1016/j.atmosres.2025.107987","DOIUrl":"10.1016/j.atmosres.2025.107987","url":null,"abstract":"<div><div>The main objective of this research, was to incorporate Mixed Layer Depth (MLD) estimations across backward air mass trajectories to the broadly used Trajectory Sector Analysis (TSA) and Concentration Weighted Trajectory (CWT) methods, in order to attain a three-dimensional (3D) identification of aerosol transport pathways and to reveal the role of the Mixed Layer (ML) on the transferring of particulates. The developed 3D-TSA and 3D-CWT tools, were combined with daily concentrations of PM₁₀-bound <span><math><msubsup><mi>SO</mi><mn>4</mn><mrow><mn>2</mn><mo>−</mo></mrow></msubsup></math></span>, <span><math><msubsup><mi>NO</mi><mn>3</mn><mo>−</mo></msubsup></math></span>, <span><math><msup><mi>Na</mi><mo>+</mo></msup></math></span>, <span><math><msup><mi>Mg</mi><mrow><mn>2</mn><mo>+</mo></mrow></msup></math></span>, <span><math><msup><mi>Ca</mi><mrow><mn>2</mn><mo>+</mo></mrow></msup></math></span> and <span><math><msup><mi>K</mi><mo>+</mo></msup></math></span> measured at three rural sampling sites in Spain during the years 2019–2020. Vertically extended Saharan dust intrusions from North Africa were associated with air masses travelling both inside and outside the ML and were related to increases of PM₁₀-bound <span><math><msubsup><mi>SO</mi><mn>4</mn><mrow><mn>2</mn><mo>−</mo></mrow></msubsup></math></span> and <span><math><msup><mi>Ca</mi><mrow><mn>2</mn><mo>+</mo></mrow></msup></math></span> at all stations, attributed to the reactions of mineral dust with gaseous precursors of <span><math><msubsup><mi>SO</mi><mn>4</mn><mrow><mn>2</mn><mo>−</mo></mrow></msubsup></math></span> such as SO₂. The advection of sea salt particles, marked by high levels of <span><math><msup><mi>Na</mi><mo>+</mo></msup></math></span> and <span><math><msup><mi>Mg</mi><mrow><mn>2</mn><mo>+</mo></mrow></msup></math></span>, was associated with marine air masses from the Mediterranean and Atlantic Ocean, moving mainly within the ML. Enhanced levels of PM₁₀ constituents emitted by anthropogenic sources, such as <span><math><msubsup><mi>NO</mi><mn>3</mn><mo>−</mo></msubsup></math></span> (traffic and industrial emissions) and <span><math><msup><mi>K</mi><mo>+</mo></msup></math></span> (biomass burning), were clearly related to air masses originating from Iberian Peninsula, Central Europe and North African coastline, whilst in most cases the strongest contributions were transferred by air masses moving above the ML. Therefore, the implemented 3D version of TSA and CWT methods, revealed new information regarding the altitudinal characteristics of air masses affecting PM₁₀ levels in Spain.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"317 ","pages":"Article 107987"},"PeriodicalIF":4.5,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143428010","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 and analysis of the modulation effect of sub-grid turbulent orographic form drag on warm-sector heavy rainfall in South China","authors":"Peilan Huang ,&nbsp;Qilin Wan ,&nbsp;Lifang Li ,&nbsp;Sheng Hu","doi":"10.1016/j.atmosres.2025.107991","DOIUrl":"10.1016/j.atmosres.2025.107991","url":null,"abstract":"<div><div>Numerical models frequently cannot accurately predict warm-sector heavy rainfall (WSHR) in South China, which presents a challenge in forecasting severe weather events in the region. Considering the substantial impact of complex orography on the forecasting of WSHR in South China, to improve the accuracy of numerical models in predicting WSHR, this study utilized the non-hydrostatic mesoscale numerical model Weather Research Forecast (WRF) to simulate a WSHR event in the Pearl River Delta from 12:00 UTC on May 9, 2022, to 12:00 UTC on May 11, 2022. The modulation effect of Turbulent Orographic Form Drag (TOFD) on the prediction accuracy of the WSHR was investigated through sensitivity tests. The simulations suggest that TOFD improved the forecasting accuracy for WSHR in South China. TOFD significantly impacted the intensity and location of WSHR in the Pearl River Delta region. After incorporating TOFD, the forecast accuracy of WSHR improved in some regions (such as Guangzhou). Specifically, in the Pearl River Delta region, the TS score for 6-h heavy precipitation (&gt;100 mm) increases by 91.12 %. The precipitation center shifts eastward, and the area affected by WSHR expands. Furthermore, the incorporation of TOFD in the simulations resulted in a delay of the WSHR onset time by 1–2 h and an extension of its duration by 1 h. Both these improvements brought the model results closer to actual observations. Additionally, with the inclusion of TOFD, the weakening of southerly winds has led to enhanced wind field convergence and stronger moisture convergence, resulting in increased moisture. In warm and moist atmospheric environments, there was an extended period of energy accumulation, resulting in a thicker mixed layer, increased negative buoyancy, and intensified upward airflow. As the system continued to move eastward, incorporating TOFD resulted in a further eastward positioning of the WSHR. Additionally, the intensity of the WSHR was stronger and the duration of intense precipitation was longer. The study highlights the critical role of TOFD in the realistic representation of WSHR by numerical models for South China.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"318 ","pages":"Article 107991"},"PeriodicalIF":4.5,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143437604","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":"Impact of different scale-aware cumulus parameterizations on precipitation forecasts over Korea","authors":"Ji-Young Han","doi":"10.1016/j.atmosres.2025.107990","DOIUrl":"10.1016/j.atmosres.2025.107990","url":null,"abstract":"<div><div>This study aims to evaluate and improve the performance of the scale-aware cumulus parameterization scheme (CPS) in the Korean Integrated Model (KIM), referred to as KSAS. The performance of the KSAS for simulating precipitation over Korea is first evaluated in comparison with other scale-aware CPSs available in the Weather Research and Forecasting (WRF) model by conducting a series of experiments at multiple horizontal resolutions, including the gray zone. The results show that the KSAS significantly improves precipitation forecast skill compared to its original version. However, its performance is lower than that of the other scale-aware CPSs at 27-km and 9-km spatial resolutions due to the substantial contribution of cumulus parameterization. To address issues in the scale-aware parameterization of KSAS, the method for defining the convective updraft fraction is revised to adopt a more physically based approach. The WRF simulation results demonstrate improved precipitation forecast skill with the revised scale-aware parameterization at the gray-zone resolution, where the contribution of cumulus parameterization is significantly reduced. Further evaluation of the revised scheme in KIM also reveals enhanced medium-range forecast skill for both large-scale fields and precipitation at horizontal resolutions of NE360NP3 (∼12 km) and NE576NP3 (∼8 km). The warm bias in the mid-latitudes of the Northern Hemisphere is alleviated by reduced convective heating. Notably, the revised scheme exhibits a pronounced improvement in the skill for forecasting precipitation over the Korean Peninsula, better capturing the pattern and intensity of the precipitation core for heavy rainfall events, as confirmed by higher skill scores.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"317 ","pages":"Article 107990"},"PeriodicalIF":4.5,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143428011","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":"Positive surface air temperature trends in a subarctic region: Analyzing the changes in dominant periodic components and energy budget","authors":"Nasrin Salehnia ,&nbsp;Chang-Hyun Park ,&nbsp;Hotaek Park ,&nbsp;Nikolai Fedorov ,&nbsp;Jinho Ahn ,&nbsp;Aleksander Fedorov ,&nbsp;Seok-Woo Son","doi":"10.1016/j.atmosres.2025.107981","DOIUrl":"10.1016/j.atmosres.2025.107981","url":null,"abstract":"<div><div>Over the past few decades, global warming has significantly impacted permafrost regions, reflecting the amplification in Arctic temperature changes. To better understand climate variability and the changes in permafrost regions, in this study, we examined the changes in the surface air temperature (SAT) in the Republic of Sakha (Yakutia, Russia) from 1971 to 2022. The data from 18 meteorological stations were considered to assess the SAT trends, percentage change (PC), and dominant periodic components across the region. Additionally, the trends of the snow depth (SD) and energy budget components (EBCs), including the net radiation (NR) and latent and sensible heat (LH and SH, respectively), were investigated to elucidate the possible reasons for the SAT trends. The results confirmed a significant increase in the SAT at all stations at both the monthly and seasonal timescales. The monthly SAT trends ranged from 0.002 °C/month to 0.007 °C/month, with considerable variations in the autumn and spring seasons. The dominant periodicity components that affected the SAT monthly trends were the 16- and 32-month across all the stations. For individual seasons, the 4- and 8-year periodic components were identified as the most dominant periodic components to affect the SAT, EBC, and SD trends. Our study can serve as a foundation for future investigations on the changes in dominant periodic components and energy budgets in subarctic regions due to global warming, thereby supporting the ongoing efforts toward climate change mitigation.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"318 ","pages":"Article 107981"},"PeriodicalIF":4.5,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143444593","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 corona sheath conductivity distribution on the transmission characteristics of return-stroke currents","authors":"Pin Lv ,&nbsp;Wangsheng Wang ,&nbsp;Ping Yuan ,&nbsp;Yingying An ,&nbsp;Tingting An ,&nbsp;Hong Deng ,&nbsp;Lizhen Yuan","doi":"10.1016/j.atmosres.2025.107982","DOIUrl":"10.1016/j.atmosres.2025.107982","url":null,"abstract":"<div><div>The study on transmission characteristics of lightning return-stroke currents along the channel is of great significance for deeply understanding the microphysical mechanisms of lightning discharge processes, improving theoretical models, and optimizing lightning protection systems. Based on the spectra obtained from three lightning processes and the waveforms of ground electric field changes caused by the lightning, the characteristic parameters such as channel temperature, linear charge density, and radius are calculated. Combined with the electrodynamics model of lightning, the propagation process of electromagnetic waves in the lightning channel and the surrounding corona sheath is simulated, and the dispersion curves, as well as the intensity changes of radial and axial electric fields are obtained under two conditions: with and without considering the electrical conductivity in the corona sheath. The impact of the actual electrical conductivity distribution in the corona sheath on the transmission characteristic of electromagnetic waves is analyzed for the first time. On this basis, the transmission law of current along the channel height at different moments for the three return-strokes is simulated. The results show that compared with the case that only the electrical conductivity of the current-carrying core channel is considered, the radial distribution of electrical conductivity in the outer corona sheath will slow down the decay rate of current transmission along the channel. The larger the radius of the high electrical conductivity channel, the smaller the decay rate of the return-stroke current along the channel. In the early stage of the return-stroke, the current intensity decays rapidly along the channel height, decaying in an exponential form. As time goes on, the current decay slows down and gradually transitions to a linear decay or a uniform distribution form. It further confirms that the decay of the return-stroke current along the channel height is mainly manifested in the early stage of the return-stroke. The radius of the current-carrying channel and the distribution of conductivity in the corona sheath are key factors affecting the transmission decay of current along the channel.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"317 ","pages":"Article 107982"},"PeriodicalIF":4.5,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143428007","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":"An Evolution-Unet-ConvNeXt approach based on feature fusion for enhancing the accuracy of short-term precipitation forecasting","authors":"Yihong Su ,&nbsp;Qiming Cheng ,&nbsp;Yang He ,&nbsp;Fei Liu ,&nbsp;Jun Liu ,&nbsp;Jiayue Zhu ,&nbsp;Ye Rao ,&nbsp;Yunsong Chao ,&nbsp;Zhen Liu ,&nbsp;Yao Chen","doi":"10.1016/j.atmosres.2025.107984","DOIUrl":"10.1016/j.atmosres.2025.107984","url":null,"abstract":"<div><div>Accurate short-term convective weather prediction is crucial for mitigating the impact of natural disasters. Although radar echo extrapolation is a commonly employed forecasting method, traditional optical flow-based approaches face computational accuracy challenges when dealing with rapidly changing weather systems. Additionally, some deep learning models experience degradation in prediction accuracy due to blurring effects over extended forecast periods. In this study, we proposed Evolution-Unet-ConvNeXt, a novel deep learning model that effectively addresses these limitations by incorporating feature fusion of latent physical information. The experiments conducted on MeteoNet dataset have demonstrated a significant enhancement in prediction accuracy and reduction of blurring effects when dealing with complex convective phenomena using this model. The Evolution module successfully extracted both motion and intensity fields from radar images, while the recently developed Unet-ConvNeXt network enhanced the efficiency of feature extraction and processing workflow. Quantitative evaluations indicated that our model achieved substantial improvements in meteorological metrics, such as Critical Success Index (CSI) and Probability of Detection (POD), as well as in image clarity and spatial structure metrics like Tenengrad (TEN) and Structure Similarity Index Measure (SSIM), compared to existing baseline model architectures. Furthermore, qualitative analysis of specific rainfall events demonstrated that the robust predictive capability of this model for the intricated nonlinear dynamics of intense echo weather systems.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"317 ","pages":"Article 107984"},"PeriodicalIF":4.5,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143418584","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}