Journal of Geophysical Research: Atmospheres最新文献

{"title":"Going Off Grid: A Comparative Study of the Lagrangian and Eulerian Perspectives of New Particle Formation Events","authors":"Samuel E. O’Donnell,&nbsp;Betty Croft,&nbsp;Bonne Ford,&nbsp;Nicole A. June,&nbsp;Chongai Kuang,&nbsp;Ashish Singh,&nbsp;Rachel Y.-W. Chang,&nbsp;Don R. Collins,&nbsp;Simo Hakala,&nbsp;Shantanu H. Jathar,&nbsp;Pauli Paasonen,&nbsp;Manish Shrivastava,&nbsp;James N. Smith,&nbsp;Jeffrey R. Pierce","doi":"10.1029/2025JD043713","DOIUrl":"10.1029/2025JD043713","url":null,"abstract":"<p>New particle formation and growth (NPF&amp;G) is the process by which ultrafine particles are formed from gas-phase precursors. NPF&amp;G is the dominant source of global aerosol number with important influences on climate. Most observations of NPF&amp;G events are conducted at stationary sites; however, NPF&amp;G observed from stationary sites is influenced by gradual or rapid changes in the air masses passing over the site, complicating NPF&amp;G analysis. In this work, we use observations and a 3D aerosol model to compare aerosol size distributions at a stationary site (Southern Great Plains [SGP] observatory, Oklahoma, USA) and along Lagrangian trajectories crossing the site. The model simulates the NPF&amp;G events reasonably well at SGP. Using the model to compare the Lagrangian and stationary perspectives, we can explain previously unanalyzable days with some evidence of NPF&amp;G as either non-event or analyzable NPF&amp;G days. We find most of the unanalyzable NPF&amp;G days are due to isolated and inhomogeneous NPF&amp;G occurring upwind of the stationary site, often in the outflow of urban regions. Finally, we compare formation rates of 3 nm particles, growth rates, and the survival probability of 3 nm particles growing to 25 nm between the stationary and Lagrangian perspectives. Because of the much larger number of analyzable days along the Lagrangian trajectories, this perspective potentially provides more robust statistics and better characterization of NPF&amp;G event extremes. Our method for extracting chemical/physical properties along Lagrangian trajectories from 3D models can be applied to a wide range of science questions.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 18","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025JD043713","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145051156","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":"Recent Intensification of Arctic Winter Anticyclonic Circulation Linked to Local Sea Ice Loss and SST Warming","authors":"Zhongfang Liu,&nbsp;Zhiqing Li,&nbsp;Wanling Xu,&nbsp;Xiaohe Huan,&nbsp;Haimao Lan","doi":"10.1029/2025JD044995","DOIUrl":"10.1029/2025JD044995","url":null,"abstract":"<p>The Arctic winter has experienced a strengthening anticyclonic anomaly over the Barents-Kara Sea (BKS) since the satellite era, driving substantial sea ice loss and warming in the region and cooling in Eurasia. However, the mechanisms behind this circulation anomaly remain uncertain. Using both observations and model simulations, we show that local sea ice loss and sea surface temperature warming are key contributors, explaining approximately 47% of the anomaly. These processes amplify local tropospheric warming relative to other Arctic regions, enhancing the horizontal gradient in thermal expansion and raising geopotential heights aloft, thereby strengthening the anticyclonic anomaly. Combined with evidence that the BKS anticyclonic anomaly itself drives local sea ice loss and warming, our results suggest a positive feedback loop, where the anomaly amplifies sea ice loss and warming, which in turn strengthens the anomaly. Although atmosphere-only models cannot fully capture these feedbacks due to the lack of interactive ocean and sea ice components, they underscore the crucial role of local forcing in amplifying the circulation anomaly. These results challenge the view that the BKS anomaly is primarily internally generated and largely independent of sea ice loss. Under continued greenhouse warming, the BKS anticyclonic anomaly is likely to further strengthen, with important implications for climate in the Arctic and beyond.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 18","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145051155","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 Daytime Production of Airborne Pollutants by SO2 Oxidation at Ocean Surface Over Eastern Asia","authors":"Yiqun Wang,&nbsp;Ruqian Miao,&nbsp;Huifan Deng,&nbsp;Zhifeng Tang,&nbsp;Zhanjun Zhu,&nbsp;Rachel Gemayel,&nbsp;Fangyuan Ma,&nbsp;Hao Wang,&nbsp;Xue Li,&nbsp;Jiangping Liu,&nbsp;Zhiqiang Yu,&nbsp;Xinming Wang,&nbsp;Qi Chen,&nbsp;Sasho Gligorovski","doi":"10.1029/2024JD043285","DOIUrl":"10.1029/2024JD043285","url":null,"abstract":"<p>Sulfur dioxide (SO₂) is oxidized to sulfate within atmospheric aerosols. However, it is also deposited on the ocean surface by dry deposition thereby reacting with the enriched organic material within sea-surface microlayer (SML) such as unsaturated fatty acids and humic substances. Here, we performed dedicated experiments on SO₂ oxidation chemistry at authentic SML sampled from 10 sites in coastal area and open sea of the South China Sea, in dark and under simulated sunlight irradiation. Real-time measurements of volatile organic compounds (VOCs) formed by SO₂ oxidation chemistry were performed by using ultra-high resolution mass spectrometry. Intriguingly, a total of 104 product compounds were identified in dark whereas 843 compounds were produced upon sunlight irradiation, during the SO₂ oxidation of the SML samples. We evaluated the potential influence of the SO₂ oxidation on SML under light irradiation as a new marine VOCs source by a chemical transport model. The simulations suggest a significant change of oxygenated VOCs in marine atmosphere over Eastern Asia that potentially alters the budgets of HO_x and RO_x radicals and consequently the lifetime of methane.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 18","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145051157","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":"Tropical Tropopause Layer Evolution During QBO Disruptions","authors":"Lan Luan,&nbsp;Paul W. Staten,&nbsp;William J. Randel,&nbsp;Ying-Hwa Kuo","doi":"10.1029/2024JD042419","DOIUrl":"10.1029/2024JD042419","url":null,"abstract":"<p>The tropical tropopause layer (TTL) is studied during 2015/16 and 2019/20 quasi-biennial oscillation (QBO) disruption events using GNSS-RO and SWOOSH satellite observations and the ERA5 reanalysis. By compositing temperature, water vapor, and tropical upwelling during different phases of QBO and QBO disruptions (XQBO), we show that XQBO events lead to cold anomalies (relative to WQBO winters) of as much as −4.6 K during April 2016 at 60 hPa and −3.9 K during December 2019 at 50 hPa. These cold anomalies initiate around 50 hPa and propagate downward, cooling the cold point tropopause (CPT). We investigate regional CPT temperature anomalies in relation to different modes of natural variability such as the QBO, the El Niño-Southern Oscillation (ENSO), and the Indian Ocean Dipole (IOD) using multiple linear regression. The warm-then-cold evolution of the CPT during November 2015–October 2016 and November 2019–October 2020 can be explained in part by the modulation of convection and Walker circulation by ENSO and the IOD and by the impact of QBO on the stratospheric upwelling as all play major roles in regulating regional CPT. CPT temperatures during the boreal summer following the two disruptions are both colder than almost all summers following WQBO winters; CPT temperatures during summer 2016 are the coldest since 1979, suggesting that any increased frequency of QBO disruptions is likely to impact atmospheric stability near the tropopause.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 18","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD042419","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145038231","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":"Formation of Oxidized Organic Aerosols in Winter Haze in a Megacity of Southwest China: Implication for the Importance of Biomass Burning","authors":"Haohui Tang,&nbsp;Zhenliang Li,&nbsp;Mi Tian,&nbsp;Chao Peng,&nbsp;Yan Ding,&nbsp;Mulan Chen,&nbsp;Xiaochen Wang,&nbsp;Yang Chen,&nbsp;Fumo Yang,&nbsp;Chongzhi Zhai","doi":"10.1029/2025JD044028","DOIUrl":"10.1029/2025JD044028","url":null,"abstract":"<p>As an important part of PM_2.5, the formation mechanism of organic aerosol is still yet to be clarified due to the complexity of its composition. In this study, the composition of non-refractory fine particles (NR-PM_2.5) in an urban area in winter Chongqing was characterized by time-of-flight aerosol chemical speciation monitor (ToF-ACSM). Organic aerosol (OA), accounting for 48.8% ± 14.6% of NR-PM_2.5, was the most abundant species. Positive matrix factorization model resolved more-oxidized oxygenated OA (MO-OOA) as the predominant component of OA (55.8% ± 11.1%), followed by less-oxidized oxygenated OA (LO-OOA) (19.0% ± 6.7%). LO-OOA exhibited dual sensitivity to both aqueous-phase processing (enhanced at higher O_x levels) and photochemical oxidation, whereas MO-OOA was predominantly photochemically derived. Moreover, photochemical oxidation preferentially promoted MO-OOA formation over LO-OOA. OA exerted a key role in forming the first haze event, which was significantly related to the enhanced production of secondary OA (SOA). Compared to the second event, the first haze exhibited significantly stronger biomass-burning emissions, likely promoting LO-OOA formation and its subsequent oxidation to MO-OOA. Moreover, biomass-burning may substantially contribute to highly oxidized OA after haze. Generally, the results of this study provide new insights into SOA formation and emphasized the need of controlling biomass burning.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 18","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145038233","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 Comprehensive Analysis of Optical Emissions, Production of NOx, HOx, and Other Chemical Species by Lightning","authors":"Francisco J. Pérez-Invernón,&nbsp;Jean-Francois Ripoll,&nbsp;Francisco J. Gordillo-Vázquez,&nbsp;Alejandro Luque,&nbsp;Pablo A. Camino-Faillace,&nbsp;Dongshuai Li,&nbsp;Torsten Neubert,&nbsp;Olivier Chanrion,&nbsp;Nikolai Østgaard","doi":"10.1029/2025JD043972","DOIUrl":"10.1029/2025JD043972","url":null,"abstract":"&lt;p&gt;We analyze lightning optical emissions and their production of different chemical species with particular emphasis on &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mtext&gt;NO&lt;/mtext&gt;\u0000 &lt;mi&gt;x&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${text{NO}}_{x}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; and &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mtext&gt;HO&lt;/mtext&gt;\u0000 &lt;mi&gt;x&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${text{HO}}_{x}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;. We calculate synthetic lightning spectra with inputs from an electrodynamical model of hot air lightning plasmas. The electrodynamical model calculates the temporal and radial evolution of plasma parameters and chemical species. We analyze 26 lightning-like discharges modeled between 0 and 16 km altitude, varying the input energy between 4 and 200 J/cm, the initial radius, the initial mass, and the humidity. We use a simplified model to estimate the peak current corresponding to each input energy. The ratio of the production of &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mtext&gt;HO&lt;/mtext&gt;\u0000 &lt;mi&gt;x&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${text{HO}}_{x}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; to &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mtext&gt;NO&lt;/mtext&gt;\u0000 &lt;mi&gt;x&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${text{NO}}_{x}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; obtained in this study for saturated air ranges between &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mn&gt;5&lt;/mn&gt;\u0000 &lt;mo&gt;×&lt;/mo&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;msup&gt;\u0000 &lt;mn&gt;0&lt;/mn&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;mn&gt;5&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $5times 1{0}^{-5}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; and &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mn&gt;2.3&lt;/mn&gt;\u0000 &lt;mo&gt;×&lt;/mo&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;msup&gt;\u0000 &lt;mn&gt;0&lt;/mn&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 ","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 18","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025JD043972","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145038176","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":"Spatiotemporal Reconstruction of Annual Glacier Mass Balance in Central Asia (2000–2020) Using Machine Learning","authors":"Yanfei Peng,&nbsp;Tobias Bolch,&nbsp;Qiangqiang Yuan,&nbsp;Francesca Baldacchino,&nbsp;Qianqian Yang","doi":"10.1029/2024JD043191","DOIUrl":"10.1029/2024JD043191","url":null,"abstract":"<p>Glaciers in High-mountain Asia play a critical role in both climate change studies and regional water resource management. However, detailed observations over a large spatial extent remain scarce. In this study, we reconstruct annual glacier-wide mass balance from 2000 to 2020 for glaciers larger than 0.1 km² across the Tien Shan and Pamir using machine learning (ML) techniques. Five ensemble ML and a deep neural network models were tested, with XGBoost demonstrating the best performance and thus selected for the reconstruction of the glacier mass balance time series. Predictor variables included meteorological data from the ERA5-Land data set and topographic features. The results indicate an average mass loss of −0.39 m water equivalent (m w.e.) per year for the studied period, with the highest losses observed in the Djungar Alatau (−0.68 m w.e. yr⁻¹), and the lowest in the eastern Pamir (−0.10 m w.e. yr⁻¹). Additionally, the results reveal that small glaciers (area &lt;1 km²) experience more rapid mass loss. The temporal evolution of glacier mass balance exhibits, on average, an acceleration but with spatiotemporal variability. Variable importance analysis identified glacier elevation and geographic location as the dominant factors influencing mass balance, followed by the temperatures of July and August. This work further advances the application of ML methods in glaciology, enhancing our understanding of regional glacier mass balance.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 18","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD043191","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145038338","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":"Future Intensity-Duration-Frequency Curves of Extreme Precipitation in the Midwest United States From Convection-Permitting Modeling","authors":"Trung Nguyen,&nbsp;Ben Kravitz,&nbsp;Travis A. O’Brien,&nbsp;Darren L. Ficklin,&nbsp;Kristen L. Rasmussen,&nbsp;Andrew Kruczkiewicz,&nbsp;Jiyun Huang,&nbsp;Tony Li,&nbsp;Abraham Lauer","doi":"10.1029/2024JD042798","DOIUrl":"10.1029/2024JD042798","url":null,"abstract":"<p>During the last four decades, global warming has statistically significant intensified extreme precipitation events in the Midwestern United States (defined here as the region covering Illinois, Indiana, Ohio, and Kentucky), leading to increased risks to human life, property, and infrastructure. To enable climate change adaptation and resilience across various economic and social sectors in this region, updated information about future climate changes, specifically at finer spatial scales, is essential. Leveraging a new 150-year dynamical downscaling data set at convection-permitting resolution, this study introduces a framework to construct the projected future intensity-duration-frequency (IDF) curves of heavy precipitation, which are prominent tools for infrastructure design and water resources management. This framework generates IDF curves at both sub-daily and multi-day duration utilizing hourly in situ observations as well as quantile-based statistical techniques in bias-correction and return levels selection. The assumption of non-stationarity in the distribution parameter fitting process is also implemented in this workflow. Compared to historical IDF curves for 1980–2022, future projected IDF curves for 2058–2100 under Representative Concentration Pathway (RCP) 4.5 and RCP 8.5 scenarios indicate an average intensity increase of approximately 15% and 25%, respectively, across 74 stations, considering both annual and seasonal timescales. Future projections suggest that extreme precipitation events may become more severe across six investigated return periods, with longer return periods showing a greater increase. The frequency of future extreme precipitation events in the Midwest region is also projected to double. Furthermore, current results reveal spatial heterogeneity of future trends across stations owing to the high-resolution input data set.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 18","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD042798","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145038339","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":"Chlorate Chemistry From Earth to Mars","authors":"Mang Lin","doi":"10.1029/2025JD045217","DOIUrl":"10.1029/2025JD045217","url":null,"abstract":"<p>Isotopic measurements indicate that chlorate and perchlorate form naturally via atmospheric oxidation of chlorine compounds, but detailed mechanisms, particularly for the more reactive chlorate, remain poorly constrained. Chan et al. (2025, https://doi.org/10.1029/2024JD042162) incorporated chlorate and perchlorate chemistry and isotopic fingerprinting into a chemical transport model. Discrepancies between observed and modeled concentrations and isotopic values highlight missing processes especially multiphase reactions of chlorate. The future directions outlined in this commentary may help clarify atmospheric chlorate chemistry and its interaction with other trace species. Given the widespread occurrence of chlorate and perchlorate on Mars, improved understanding of chlorate chemistry will inform their roles in liquid water stability, organic preservation, planetary habitability, and the search of potential Martian biosignatures.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 18","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025JD045217","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145037710","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":"Investigating Aerosol Hygroscopicity in the Subcloud Transition Zone and at the Surface in the Southern Great Plains","authors":"Rong Hu,&nbsp;Zhanqing Li,&nbsp;Tianning Su","doi":"10.1029/2024JD041925","DOIUrl":"10.1029/2024JD041925","url":null,"abstract":"<p>Aerosols beneath a cloud base, a subcloud transition zone (SCTZ), are key to understand both the aerosol-cloud interaction and aerosol-radiation interactions. Lidars have been the primary means of observing aerosols in the SCTZ by virtue of enhanced light scattered by aerosol particles. The enhanced light maybe caused by several factors: the aerosol swelling effect due to hygroscopicity under high relative humidity, cloud 3-dimensional (3D) effect, aerosol nucleation into cloud droplets, etc. While each factor and process has been known, their relative contributions are much poorly quantified. This study explores the hygroscopicity and optical properties of aerosols in the SCTZ and at ground level in the Southern Great Plains (SGP) region. Utilizing comprehensive observational data from the U.S. Department of Energy's Atmospheric Radiation Measurement at the Oklahoma SGP site, including ground-based aerosol measurements and Raman lidar profiles from April 2021 to April 2022, this study extensively analyzes the influence of aerosol hygroscopic growth and cloud fragments on aerosol optical properties. Distinct seasonal variations in aerosol hygroscopic characteristics are revealed. At the ground level, aerosols in autumn and winter exhibit stronger hygroscopicity due to a higher proportion of inorganic content than summer. In the SCTZ, aerosols during summer show enhanced backscatter due to strong cloud fragmentation effects, with numerous cloud fragments elevating hygroscopicity beyond that observed in autumn and winter. These insights are crucial for understanding the interactions between aerosols at the surface and cloud layers, evaluating cloud condensation nuclei beneath clouds, and their implications for atmospheric radiation and climate modeling.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 17","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD041925","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145021968","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}