Atmospheric Research最新文献

{"title":"How the unparalleled dust storm over the Arabian Peninsula in May 2022 exacerbated the record-breaking heatwave in China in the ensuing summer","authors":"Dapeng Zhang ,&nbsp;Yanyan Huang ,&nbsp;Jin Dai ,&nbsp;Botao Zhou ,&nbsp;Zhicong Yin ,&nbsp;Huijun Wang","doi":"10.1016/j.atmosres.2025.108054","DOIUrl":"10.1016/j.atmosres.2025.108054","url":null,"abstract":"<div><div>Against the background of global warming, the increasing frequency of extreme high-temperature events (EHTF) in East China poses a huge threat to societal development and public health, and this was starkly demonstrated by the record-breaking EHTF observed in China in summer 2022. In this study, it was found that the record-breaking dust storm in May 2022 over the Arabian Peninsula accounted for approximately 65.2 % of the abnormal amplitude of July–August EHTF in China in the ensuing summer. Mechanistically, the dust aerosols of this heavy dust storm over the Arabian Peninsula were transferred downstream by the trade winds, whereupon they cooled the Indian Ocean via radiative processes and warmed the Tibetan Plateau through the so-called “snow-darkening effect”. These dust effects persisted until late summer and consequently strengthened the Indian summer monsoon and wetted the Indochina Peninsula. Subsequently, the associated enhanced and eastward-shifted South Asian high and westward-shifted western Pacific subtropical high contributed to the record-breaking EHTF in 2022. A physical–empirical forecast model was developed based on the preceding May dust signals over the Arabian Peninsula, and results showed that it skillfully predicts the interannual variability of July–August EHTF in East China during 2009–2022, and especially the record-breaking amplitude in 2022.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"320 ","pages":"Article 108054"},"PeriodicalIF":4.5,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143672863","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":"Coupling effects of moisture sources and meteorological factors on stable isotopes in precipitation over the Hunshandake Sandy Land, northern China","authors":"Yusheng Hao ,&nbsp;Debin Jia ,&nbsp;Wenxu Su ,&nbsp;Weiying Feng","doi":"10.1016/j.atmosres.2025.108058","DOIUrl":"10.1016/j.atmosres.2025.108058","url":null,"abstract":"<div><div>Effective management of water resources and the development of climate adaptation strategies in arid and semi-arid regions increasingly rely on a comprehensive understanding of water cycle processes in the context of global climate change. This study focuses on the Hunshandake Sandy Land, a key ecological barrier in northern China. It analyzes the influence of climate conditions and moisture sources on precipitation isotope composition using 394 precipitation samples collected between 2014 and 2021. Precipitation δ¹⁸O and d-excess show significant variability and distinct seasonal patterns, with δ¹⁸O values ranging from 1.78 ‰ to −24.51 ‰ and d-excess values from −26.28 ‰ to 39.08 ‰. Temperature is identified as the primary factor influencing precipitation δ¹⁸O and d-excess, accounting for 42 % of the monthly δ¹⁸O variation and 16 % of the monthly d-excess variation. The Local Meteoric Water Line, δ²H = 6.66δ¹⁸O – 3.48, highlights the dry, low-rainfall, and high-evaporation characteristics of the Hunshandake Sandy Land. The backward trajectory calculations reveal that northern China, central China, and Mongolia are the primary sources of moisture absorption, contributing 38.25 %, 26.20 %, and 14.21 % of the moisture to Hunshandake Sandy Land precipitation, respectively. The influence of monsoon climates varies over time, leading to significant variability in the contribution of different moisture source regions to Hunshandake Sandy Land precipitation. Specifically, northern China contributes 36.09 % of the moisture in the wet season and 40.42 % in the dry season, whereas central China contributes 29.39 % in the wet season and 23.02 % in the dry season. The Hunshandake Sandy Land precipitation sample index (I_HSL) was defined, and a multiple linear model for monthly precipitation δ¹⁸O values was developed using temperature, relative humidity, and I_HSL: (δ¹⁸O = 0.320 T - 0.068RH + 0.022 I_HSL - 11.615). This model can explain 49 % of the monthly precipitation δ¹⁸O variability.These findings enhance the understanding of the water cycle in arid and semi-arid regions.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"320 ","pages":"Article 108058"},"PeriodicalIF":4.5,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143672865","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":"Satellite-based extreme precipitation estimation using convolution neural networks and ant colony optimized multi-layers perceptron","authors":"Reza Nosratpour,&nbsp;Laleh Tafakori,&nbsp;Mali Abdollahian","doi":"10.1016/j.atmosres.2025.108037","DOIUrl":"10.1016/j.atmosres.2025.108037","url":null,"abstract":"<div><div>Extreme precipitation events have recently increased due to global warming, leading to higher humidity and temperatures. Therefore, accurate, updated, and comprehensive precipitation estimations are essential to mitigate the severe losses caused by these extreme events. Satellite precipitation products provide high spatiotemporal resolution and global coverage, enabling improved detection and estimation of precipitation, especially in areas with limited ground observations. This research leverages some of the advanced satellite precipitation products and atmospheric dataset reanalysis available, enhancing the accuracy of precipitation estimates, particularly during heavy and extreme precipitation events. In this work, we use Convolutional Neural Networks (CNN) and optimization techniques to introduce a two-step methodology for improving satellite-based estimation and detection of heavy and extreme precipitation events. In the first step, feature centroids are integrated into a resampling method to increase the diversity of samples. The second step applies the Ant Colony Optimization (ACO) algorithm to refine categorical evaluation criteria, enhancing prediction accuracy. This study uses the ACO meta-heuristic algorithm to optimize a Multi-Layer Perceptron (MLP) model, using CNN-based precipitation estimates as input. The performance of the models and products in estimating and detecting heavy and extreme precipitation events is evaluated using various metrics, including Pearson correlation (r) and Kling-Gupta Efficiency (KGE). The results show that the Ant Colony-optimized MLP (ACO-MLP) outperforms the satellite precipitation products and CNN models in estimating the extreme and heavy precipitation with <em>r</em> = 0.89, 0.82, and KGE = 0.71, 0.65, over the continental area of Australia. The result of utilizing the proposed ACO-MLP and CNN models in Australia showed that the spatial pattern of the extreme precipitation event over the country's east coast on 23 February 2022 is effectively captured. This work contributes to improving water resources management and advancing climate studies, particularly in understanding and addressing extreme precipitation conditions.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"320 ","pages":"Article 108037"},"PeriodicalIF":4.5,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143679560","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":"Understanding the aerosol impact on the electrification of PyroCb thunderstorm","authors":"Surajit Das Barman,&nbsp;Rakibuzzaman Shah,&nbsp;Syed Islam,&nbsp;Apurv Kumar","doi":"10.1016/j.atmosres.2025.108029","DOIUrl":"10.1016/j.atmosres.2025.108029","url":null,"abstract":"<div><div>Understanding and predicting pyrocumulonimbus (pyroCb) thunderclouds is challenging due to their unpredictable nature and potential to exacerbate wildfires. This study employs a three-dimensional (3D) numerical model with a non-inductive electrification mechanism to explore how fire-produced aerosol concentrations influence the charge structure and lightning activity in pyroCb. Aerosol particle concentrations ranging from 100 to 20,000 cm⁻³ were considered to generate realistic thundercloud charge structures, with the cumulus cloud setup based on environmental conditions derived from an inverted-V sounding profile. The SP98 non-inductive electrification scheme models charge transfer in pyroCb, and the Poisson equation is solved to identify regions where lightning discharges are likely to initiate, though actual discharges are not simulated. For aerosol concentrations between 500 and 5000 cm⁻³, negative non-inductive charging dominates, while extreme aerosol cases (<span><math><mo>≥</mo></math></span>5000 cm⁻³) enhance positive charging at altitudes of 3–7 km. These findings suggest that non-inductive charge separation between ice crystals and graupel leads to realistic charge structures under pyroconvective conditions simulated in this study, reflecting moderate-to-high aerosol environments characteristic of wildfire-driven pyroCb events. As aerosol concentrations increase from 500 to 5000 cm⁻³, the charge structure evolves from a dipole to a tripole (at 1000 cm⁻³) and eventually to an inverted dipole, enabling intra-cloud (IC) and negative cloud-to-ground (-CG) lightning. At higher concentrations (10,000–20,000 cm⁻³), a multi-layer charge configuration emerges, favoring intense positive cloud-to-ground (+CG) strokes. Sensitivity analysis reveals that low-to-moderate aerosol levels with strong wind shear promote IC lightning, while high aerosol levels favor +CG flashes. These findings highlight the complex interactions driving pyroCb dynamics and the importance of integrated modelling to predict wildfire-induced thunderstorms.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"320 ","pages":"Article 108029"},"PeriodicalIF":4.5,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143644145","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":"Terrain and urban impacts on summer extreme precipitation over Henan, China: A synoptic and simulation analysis","authors":"Shuang Chen ,&nbsp;Ben Yang ,&nbsp;Anning Huang ,&nbsp;Yan Zhang","doi":"10.1016/j.atmosres.2025.108033","DOIUrl":"10.1016/j.atmosres.2025.108033","url":null,"abstract":"<div><div>The impacts of terrain and urban surfaces on regional hourly extreme precipitation events (RHEPE) in Henan Province of China under specific synoptic conditions remain unclear. In this study, we first identify the dominant synoptic patterns associated with the summer RHEPEs in Henan and surrounding areas by employing spectral clustering methods, revealing that 86 % of RHEPEs are induced by the low vortexes and 14 % by the tropical cyclones, with the latter contributing to the most extreme RHEPEs. Then, based on numerical experiments and moisture budget decomposition, we quantify the effects of terrain and urban surfaces on RHEPE under the most extreme synoptic pattern featured by tropical cyclones. Results suggest that the terrains cause remarkable increases in precipitation primarily along the windward slopes of the Funiu Mountains and Taihang Mountains by 34 % and 26 %, respectively, this can be explained by the enhanced dynamical component of moisture convergence due to the blocking effect of terrains. Compared to the terrain, the impacts of urban surfaces are much smaller (only 1 %) and spatially limited. The much larger surface roughness in the urban areas reduces the horizontal wind speed and causes weakened wind convergence, leading to decreased precipitation over the urban areas. Meanwhile, when traversing the urban areas, the horizontal winds bifurcating and rejoining in the downwind areas increase the low-level convergence and precipitation there. Findings of this study may deepen our understanding of the influences of terrain and urban surfaces on the RHEPE and associated mechanisms under the extreme synoptic pattern.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"320 ","pages":"Article 108033"},"PeriodicalIF":4.5,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143580846","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":"Evaluating clear-sky assimilation of FengYun-3E microwave radiance data in predicting multiple tropical cyclones over the Western North Pacific","authors":"Di Fang ,&nbsp;Guanghua Chen ,&nbsp;Xingou Xu ,&nbsp;Yuhui Zhao ,&nbsp;Ziqing Wang","doi":"10.1016/j.atmosres.2025.108025","DOIUrl":"10.1016/j.atmosres.2025.108025","url":null,"abstract":"<div><div>Since the successful launch and operation of the FengYun-3E (FY-3E) satellite, the assessment of its data quality and applications has garnered significant attention. By comparison with previous studies focusing on the assessment on a single case, this research assimilates the Microwave Humidity Sounder-2 (MWHS-2) and the Microwave Temperature Sounder-3 (MWTS-3) data to evaluate the track and intensity prediction of 19 tropical cyclones (TCs) over the western North Pacific (WNP). This comprehensive investigation seeks to unravel the contributions of microwave radiance onboard FY-3E to the initial fields in the multi-typhoon predictions. For each TC case, three experiments are carried out to evaluate the effect of microwave radiance data on clear-sky assimilation: the control experiment (CONV) assimilates only conventional data, while the other two experiments incorporate MWHS-2 (MWHS) and MWTS-3 (MWTS) data, respectively. The results indicate that MWHS and MWTS exert distinct effects on dynamical and thermodynamic variables across various atmospheric levels. The positive impact of MWHS and MWTS on the track and intensity forecast has been proven, respectively, with the root mean square errors reduced by 3.86 % for track, 4.76 % for maximum wind speed (MWS), and 7.78 % for minimum surface level pressure (MSLP) relative to CONV. For the three-day average forecast errors, the MWHS exhibits the lowest daily mean track error, while the MWTS primarily contributes to reducing the MSLP error on the second day and the MWS error on the first and third days.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"320 ","pages":"Article 108025"},"PeriodicalIF":4.5,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143609624","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":"Type-based assessment of aerosol direct radiative effects: A proof-of-concept using GEOS-Chem and CATCH","authors":"Bethany Sutherland ,&nbsp;Nicholas Meskhidze","doi":"10.1016/j.atmosres.2025.108036","DOIUrl":"10.1016/j.atmosres.2025.108036","url":null,"abstract":"<div><div>The radiative perturbation of the Earth's energy balance caused by all aerosols, the direct radiative effect (DRE), and anthropogenic aerosols, the direct radiative forcing (DRF), remain major sources of uncertainty in climate projections. Here we propose a method for determining DRE and DRF that makes use of the High Spectral Resolution Lidar (HSRL)-retrieved aerosol loading and derived aerosol types (i.e. dust, marine, urban, smoke, etc.) in combination with aerosol-type specific optical properties. As the global spatiotemporal distributions of HSRL-derived aerosol types are not currently available, the methodology is tested here using a global 3-D model of atmospheric chemistry (GEOS-Chem) along with Creating Aerosols from CHemistry (CATCH) algorithm-generated aerosol types analogous to ones derived by HSRL. In this method, the Rapid Radiative Transfer Model for General Circulation Models (RRTMG) is used to perform radiative transfer calculations with the single scattering albedo (SSA) and asymmetry parameter (g) of atmospheric particles assigned based on the aerosol type in each grid box. Average GEOS-Chem/CATCH-derived all-sky DRE and DRF across the North American domain are estimated to be −1.98 W/m² and − 0.77 W/m², respectively between mid-January and early February 2013 and − 4.20 W/m² and − 1.41 W/m² respectively between mid-July and early August 2014. Sensitivity studies revealed that the scheme may produce up to about ±0.42 W/m² and ± 0.21 W/m² uncertainty in DRE and DRF, respectively, related to variability in aerosol type-specific optical properties. This study presents a new way of determining DRE and DRF estimates once global retrievals of aerosol intensive parameters by HSRL become available.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"320 ","pages":"Article 108036"},"PeriodicalIF":4.5,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143594185","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":"Extreme wildfires over Northern Greece during Summer 2023 – Part B. Adverse effects on regional air quality","authors":"Maria-Elissavet Koukouli,&nbsp;Andreas Pseftogkas,&nbsp;Dimitris Karagkiozidis,&nbsp;Marios Mermigkas,&nbsp;Thomas Panou,&nbsp;Dimitris Balis,&nbsp;Alkiviadis Bais","doi":"10.1016/j.atmosres.2025.108034","DOIUrl":"10.1016/j.atmosres.2025.108034","url":null,"abstract":"&lt;div&gt;&lt;div&gt;The frequency, severity, and duration of wildfires are on the rise worldwide, underscoring the importance of comprehending the health impacts of wildfire exposure. The main aim of this work is to examine the effects that the Northern Greece forest fires during August 2023 had on regional air quality levels. On August 21st, a massive forest fire started within the Dadia Forest National Park, a protected area, nearby the city of Alexandroupoli. During the nearly ten-day duration of the fire, approximately 80,000 ha burned, while the strong prevailing easterly winds transported smoke particles and biomass burning gases over Northern Greece and the Mediterranean Sea, reaching the coasts of Italy and Tunisia. Using both spaceborne observations of nitrogen dioxide (NO&lt;sub&gt;2&lt;/sub&gt;), formaldehyde (HCHO) and carbon monoxide (CO), as well as ground-based instrumentation in the city of Thessaloniki, the extend of the degradation of air quality has been quantified. The spatially resolved Sentinel-5P TROPOspheric Monitoring Instrument (S5P/TROPOMI) observations showed how the fire plumes spread throughout Northern Greece, degrading massively the air quality near the fire event as well as over Thessaloniki, some 300 km to the west. NO&lt;sub&gt;2&lt;/sub&gt; levels were enhanced up to 82 % over the fire location whereas in the metropolis of Thessaloniki by 36 %, testifying to the extent of the fire, the dispersion of the plume and the emission strength. During the main fire days HCHO levels were shown to be enhanced by 54 % in the greater area of Alexandroupoli and by 114 % in the vicinity of Thessaloniki, in line with other works. The longer-lived CO was found similarly enhanced in both locations, ∼26 %, with a longer lasting effect to regional air quality. Ground-based remote sensing resulted in similar findings with MAX-DOAS spectrophotometer observations of nitrogen dioxide capturing the build-up of the transported NO&lt;sub&gt;2&lt;/sub&gt; load over Thessaloniki with morning levels reaching 30 Pmolec/cm&lt;sup&gt;2&lt;/sup&gt;, testifying to the magnitude of the transported NO&lt;sub&gt;2&lt;/sub&gt; loads well beyond the stable variability of the typical August mean NO&lt;sub&gt;2&lt;/sub&gt; levels of 10 Pmolec/cm&lt;sup&gt;2&lt;/sup&gt;. The MAX-DOAS also measured increased formaldehyde levels throughout the days of the fire event, between 25 and 35 Pmolec/cm&lt;sup&gt;2&lt;/sup&gt;, unaffected by the photochemical processes destroying NO&lt;sub&gt;2&lt;/sub&gt;, and well beyond the typical summertime levels of ∼12 Pmolec/cm&lt;sup&gt;2&lt;/sup&gt;. FTIR spectroscopy observations, also routinely performed over Thessaloniki, revealed that the long-lived carbon monoxide levels exceeded the expected background loads by more than 100.00 ± 10.61 ppb on the second major fire day. The predicted frequency increase of such major wildfire events places an imperative need for changes in the typical urban air quality monitoring practices currently in place, to account for unexpected degradation of the breathable air, as well as changes on how mitigation measu","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"320 ","pages":"Article 108034"},"PeriodicalIF":4.5,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143636871","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":"Local and regional enhancements of GHGs in Thessaloniki, inferred from ground-based FTIR measurements","authors":"Marios Mermigkas ,&nbsp;Chrysanthi Topaloglou ,&nbsp;Dimitrios Balis ,&nbsp;Frank Hase ,&nbsp;Darko Dubravica","doi":"10.1016/j.atmosres.2025.108035","DOIUrl":"10.1016/j.atmosres.2025.108035","url":null,"abstract":"<div><div>Global warming and subsequent climate change are currently a major issue both in the scientific community and the society. Therefore it is highly important to consistently monitor the concentrations of greenhouse gases that affect the incoming-outgoing energy balance. To that end, a portable Bruker EM27/SUN FTIR spectrometer is operated in Thessaloniki, Greece since January 2019, performing measurements of total column-averaged dry air mole fractions of trace gases, denoted as X-gases. In this study, we demonstrate the utility of available measurements of greenhouse gases (GHGs) to identify the origin of enhanced concentrations. Copernicus Atmosphere Monitoring Service (CAMS) reanalysis data are used synergetically with FTIR measurements. XCO₂ shows an obvious annual increase (over 2.2 ppm per year) and a clear seasonal variation with high increased concentrations during cold season and decreased concentration during summer period due to photosynthesis activity. XCH₄ shows an annual increase and a positive trend. The continuous fire episodes in Athens and North Evia during July and August 2021 led to an unprecedented increase in the concentrations of CO of over 130 %, compared to the typical averaged mean values during August in Thessaloniki. In this paper we investigate the seasonal dependency between CO-CO₂ and CO-CH₄ enhancements with respect to the prevailing wind direction and we examine if meteorological parameters, such as wind direction and speed, could reveal the origin of enhanced X-gas variations. We applied two different approaching methods to detect long-term and short-term signals of the trace gases. In general, concerning the FTIR measurements, during summer and autumn XCO₂, XCO and XCH₄ enhancements are observed for low and medium speed winds. Winds mainly originating from SW directions have transported large amounts of CO₂, CO and CH₄ from the big fires near Athens and N. Evia in summer 2021 to Thessaloniki. The fire emissions generate higher variability of the columns of target gases (over 0.022 ppm in the S and SW wind direction).</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"319 ","pages":"Article 108035"},"PeriodicalIF":4.5,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143562627","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":"Characteristics of orographic clouds and associated mechanisms in the Qilian Mountains, northeastern Tibetan Plateau based on FengYun-4A satellite TBB product","authors":"Yi Chang ,&nbsp;Qianrong Ma ,&nbsp;Peng Qi ,&nbsp;Xueliang Guo ,&nbsp;Dawei Lin ,&nbsp;Lijun Guo ,&nbsp;Di Di ,&nbsp;Yang Zhao ,&nbsp;Hui Wang ,&nbsp;Tianyu Chen","doi":"10.1016/j.atmosres.2025.108031","DOIUrl":"10.1016/j.atmosres.2025.108031","url":null,"abstract":"<div><div>The Qilian Mountains (QM) in northwest China is a key source of orographic cloud formation, significantly influencing regional weather, climate, and hydrological balance. However, due to the sparse distribution of ground-based observational stations, the characteristics of orographic clouds and their associated precipitation remain insufficiently understood. Utilizing FengYun-4A black body temperature (TBB) data from 2018 to 2021 in boral summer, this study investigated the spatial and diurnal characteristics of orographic clouds and associated mechanisms over the QM. Results indicate that orographic clouds primarily form over the mountainous terrain, with deep convective clouds concentrated in the central and eastern QM. A distinct diurnal cycle is observed, with peak cloud activity occurring in the afternoon to early evening (15:00–19:00 local solar time), minimal activity late at night, and the weakest development in the morning. These variations are more pronounced in the central and eastern QM, where cloud formation persists for longer durations, compared to the western region. Three dominant diurnal cloud cycles are identified in the southeast, northeast, and eastern fringes of the western, central, and eastern QM, respectively, along with smaller-scale cycles along mountain ridges. Orographic cloud formation is driven by the convergence of low-level westerlies and the Asian monsoon, with moisture contributions from the westerlies, the Tibetan Plateau, and the monsoon system. Additionally, interactions between solar heating and complex terrain shape the spatial and diurnal distribution of these clouds. These findings enhance our understanding of regional water cycles and provide valuable insights for weather and climate research.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"320 ","pages":"Article 108031"},"PeriodicalIF":4.5,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143636867","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}