Journal of Geophysical Research: Atmospheres最新文献

{"title":"Local and Remote Effects of the Sub-Grid Turbulent Orographic Form Drag on the Summer Monsoon Precipitation Over Eastern China","authors":"Yuchen Zhou,&nbsp;Anning Huang,&nbsp;Xin Li,&nbsp;Chunlei Gu,&nbsp;Yang Wu","doi":"10.1029/2024JD041173","DOIUrl":"https://doi.org/10.1029/2024JD041173","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <p>The sub-grid turbulent orographic form drag (STOFD) significantly affects the regional circulation and precipitation. This study explores the local and remote effects of the STOFD on the summer monsoon precipitation across Eastern China using the Regional Climate Model Version 4 adopting a STOFD scheme. Results indicate that the local and remote effects of the STOFD primarily influence the improvement of summer precipitation simulation in the Southeastern and Northern China, respectively. The local effects of the STOFD can lead to 37.1% and 10.7% reduction of the absolute error and the root mean square error (RMSE) of simulated summer precipitation in the Southeastern China with complex sub-grid terrains. The remote effects of the STOFD within the Indochina Peninsula and Yunnan-Guizhou Plateau result in the absolute error and RMSE of simulated summer precipitation in the Northern China with mild sub-grid terrain decreased by 90.1% and 32.9%, respectively. Moreover, the remote effects of the STOFD within the Tianshan Mountains and Tibetan Plateau can clearly improve the simulated precipitation in both the Southeastern and Northern China. The disturbances generated by the local effects of the STOFD are more locally concentrated than those produced by the STOFD remote effects, leading to a more significant improvement of precipitation simulation in the Southeastern China. While the disturbances resulted from the remote effects of the STOFD affect the summer precipitation in both the Southeastern and Northern China obviously. This study highlights the significance of the remote effects of the STOFD in improving the summer precipitation simulation in Eastern China.</p>\u0000 </section>\u0000 </div>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142449060","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":"Evaluation of the Representation of Raindrop Self-Collection and Breakup in Two-Moment Bulk Models Using a Multifrequency Radar Retrieval","authors":"L. Niquet,&nbsp;F. Tridon,&nbsp;P. Grzegorczyk,&nbsp;A. Causse,&nbsp;B. Bordet,&nbsp;W. Wobrock,&nbsp;C. Planche","doi":"10.1029/2024JD041269","DOIUrl":"https://doi.org/10.1029/2024JD041269","url":null,"abstract":"<p>Using multifrequency radar observations providing raindrop size distribution evolution with high spatial and temporal resolution, this study aims to assess the ability of different parameterizations of raindrop self-collection and breakup processes applied in mesoscale models, to reproduce the statistics derived from observations. The stratiform zones of two types of precipitating systems are studied, a frontal situation that occurred over Finland in June 2014 and a squall line system observed over Oklahoma in June 2011. An analysis method for determining raindrop trajectories was used to obtain the temporal variation of the total raindrop concentration from the observations. The resulting raindrop concentration rate as a function of the mean volume diameter reveals significant differences with the parameterizations currently used in two-moment bulk microphysics schemes. These results show that even if they produce variations in raindrop concentration of the same order of magnitude as the observations, the current parameterizations diverge from the median of the observations, resulting in an overestimation of either the self-collection or the breakup process. From the median of radar observations, new parameterizations of the self-collection and breakup processes and of rain self-collection efficiency are developed and can be implemented in two-moment bulk microphysics schemes.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142447578","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":"Calculating Radio Emissions of Positive Streamer Phenomena Using 3D Simulations","authors":"Hemaditya Malla,&nbsp;Yihao Guo,&nbsp;Brian M. Hare,&nbsp;Steven Cummer,&nbsp;Alejandro Malagón-Romero,&nbsp;Ute Ebert,&nbsp;Sander Nijdam,&nbsp;Jannis Teunissen","doi":"10.1029/2024JD041385","DOIUrl":"https://doi.org/10.1029/2024JD041385","url":null,"abstract":"<p>We study radio emissions from positive streamers in air using 3D simulations, from which the radiated electric field is computed by solving Jefimenko’s equations. The simulations are performed at <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>0.5</mn>\u0000 <mspace></mspace>\u0000 <mi>b</mi>\u0000 <mi>a</mi>\u0000 <mi>r</mi>\u0000 </mrow>\u0000 <annotation> $0.5,mathrm{b}mathrm{a}mathrm{r}$</annotation>\u0000 </semantics></math> using two photoionization methods: the Helmholtz approximation for a photon density and a Monte Carlo method using discrete photons, with the latter being the most realistic. We consider cases with single streamers, streamer branching, streamers interacting with preionization and streamer-streamer encounters. We do not observe a strong VHF radio signal during or after branching, which is confirmed by lab experiments. This indicates that the current inside a streamer discharge evolves approximately continuously during branching. On the other hand, stochastic fluctuations in streamer propagation due to Monte Carlo photoionization lead to more radio emission being emitted at frequencies of 100 MHz and above. Another process that leads to such high-frequency emission is the interaction of a streamer with a weakly preionized region, which can be present due to a previous discharge. In agreement with previous work, we observe the strongest and highest-frequency emission from streamer encounters. The amount of total energy that is radiated seems to depend primarily on the background electric field, and less on the particular streamer evolution. Finally, we present approximations for the maximal current along a streamer channel and a fit formula for a streamer's current moment.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD041385","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142447534","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":"Machine Learning-Driven Spatiotemporal Analysis of Ozone Exposure and Health Risks in China","authors":"Chendong Ma,&nbsp;Jun Song,&nbsp;Maohao Ran,&nbsp;Zhenglin Wan,&nbsp;Yike Guo,&nbsp;Meng Gao","doi":"10.1029/2024JD041593","DOIUrl":"https://doi.org/10.1029/2024JD041593","url":null,"abstract":"<p>Accurate and fine-scaled prediction of ozone concentrations across space and time, as well as the assessment of associated human risks, is crucial for protecting public health and promoting environmental conservation. This paper introduces NetGBM, an innovative machine-learning model designed to comprehensively model ozone levels across China's diverse topography and analyze the spatiotemporal distribution of ozone and exposure. Our model focuses on daily, weekly, and monthly predictions, achieving commendable <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msup>\u0000 <mi>R</mi>\u0000 <mn>2</mn>\u0000 </msup>\u0000 </mrow>\u0000 <annotation> ${mathrm{R}}^{2}$</annotation>\u0000 </semantics></math> coefficients of 0.83, 0.77, and 0.79, respectively. By constructing a gridded map of ozone and incorporating both land use and meteorological features into each grid, we achieved ozone prediction at a high spatiotemporal resolution, outperforming previous research in terms of performance and scale, particularly in regions with limited monitoring stations. The results can be further improved when applied to regional research using meteorological and ozone data from regional stations. Additionally, our research revealed that temperature is the most significant factor affecting ozone concentrations across China. In health risk assessment, we retrieved a high-resolution spatial distribution of ozone-attributed mortality for 5-COD and daily ozone inhalation distributions during our study period. We concluded that ozone-attributed mortality is predominantly caused by stroke and IHD, accounting for more than 70% of the total deaths in 2021, with the highest mortality rates in developed urban areas such as the NCP and the YRD. Our experiment demonstrated the potential of NetGBM in robustly modeling ozone across China with high spatiotemporal resolution and its applicability in measuring associated health risks.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD041593","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142447705","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":"Diagnosing Atmospheric Heating Rate Changes Using Radiative Kernels","authors":"Han Huang,&nbsp;Yi Huang","doi":"10.1029/2024JD041594","DOIUrl":"https://doi.org/10.1029/2024JD041594","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <p>Atmospheric radiative heating rate, which manifests radiative energy convergence in the atmosphere, is a fundamental factor shaping the Earth's climate and driving climate change. Compared to the radiative energy budget at the top of atmosphere or surface, the atmospheric energy budget and heating rate are less studied due to a lack of observational constraints and diagnostic tools. Motivated by growing interest in atmospheric energy budget and to facilitate the heating rate analysis, we innovate a set of radiative kernels, which quantitatively measure the sensitivity of atmospheric heating rate to different geophysical variables. When multiplied with the changes in these geophysical variables, these kernels quantify their contributions to the heating rate change. A climate change experiment of Global Climate Models (GCMs) is used to test the application of heating rate kernels. The results indicate the radiative heating rate change simulated by GCMs can be well reproduced by the kernels, validating the kernel method. The decomposition of the heating rate changes reveals the contributing mechanisms. For example, in the tropical upper troposphere, the negative heating anomaly in a warmer climate is dominated by atmospheric temperature and water vapor. Increases in both variables intensify atmospheric thermal radiation to space, partially offset by a positive heating anomaly caused by the lifting high-cloud tops. Moreover, compared to the results corrected using the kernels, the cloud effect inferred from the radiative heating difference between clear- and all-skies (“cloud radiative heating”) has a non-negligible bias, necessitating the use of kernels to quantify the cloud-induced heating rate changes.</p>\u0000 </section>\u0000 </div>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD041594","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142447497","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":"Electromagnetic Model of K-Changes","authors":"Petr Kašpar,&nbsp;Thomas Marshall,&nbsp;Maribeth Stolzenburg,&nbsp;Ivana Kolmašová,&nbsp;Ondřej Santolík","doi":"10.1029/2023JD040503","DOIUrl":"https://doi.org/10.1029/2023JD040503","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <p>K-changes are observed as step-like increases in the thundercloud electric fields. The K-changes occur in the late part of intra-cloud lightning or during negative cloud-to-ground lightning between return strokes. It has been shown that the processes leading to K-changes initiate in the decayed part of a positive leader channel and propagate toward the flash origin. They are often accompanied by microsecond-scale electric field pulses. We introduce a new model to simulate processes leading to the K-changes in cloud-to-ground lightning. Our method is based on the full solution of Maxwell's equations coupled to Poisson's equation for the thundercloud charge structure. To model the K-changes, we gradually increase the decayed channel conductivity. The modeled current wavefront propagates due to the K-processes downward along a vertical channel and completely attenuates before reaching the ground. We derive the evolution of the linear charge densities and the scalar electric potential along the channel leading to K-changes. We model electrostatic step-like changes in the measured electric field together with the approximate rates and amplitudes of the microsecond scale pulses. Step-like changes increase their amplitudes with the length of the simulated channel and with a higher conductivity of the channel. The microsecond-scale pulse waveshapes depend mainly on the propagation velocity of the current wave, and the time scale of the conductivity increase. We show that our modeled waveforms are in a good agreement with observations conducted in Florida.</p>\u0000 </section>\u0000 </div>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142435715","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":"Inferring Surface NO2 Over Western Europe: A Machine Learning Approach With Uncertainty Quantification","authors":"Wenfu Sun,&nbsp;Frederik Tack,&nbsp;Lieven Clarisse,&nbsp;Rochelle Schneider,&nbsp;Trissevgeni Stavrakou,&nbsp;Michel Van Roozendael","doi":"10.1029/2023JD040676","DOIUrl":"https://doi.org/10.1029/2023JD040676","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <p>Nitrogen oxides (NO_x = NO + NO₂) are of great concern due to their impact on human health and the environment. In recent years, machine learning (ML) techniques have been widely used for surface NO₂ estimation with rapid developments in computational power and big data. However, the uncertainties inherent to such retrievals are rarely studied. In this study, a novel ML framework has been developed, enhanced with uncertainty quantification techniques, to estimate surface NO₂ and provide corresponding data-induced uncertainty. We apply the Boosting Ensemble Conformal Quantile Estimator (BEnCQE) model to infer surface NO₂ concentrations over Western Europe at the daily scale and 1 km spatial resolution from May 2018 to December 2021. High NO₂ mainly appears in urban areas, industrial areas, and roads. The space-based cross-validation shows that our model achieves accurate point estimates (<i>r</i> = 0.8, <i>R</i>² = 0.64, root mean square error = 8.08 μg/m³) and reliable prediction intervals (coverage probability, PI-50%: 51.0%, PI-90%: 90.5%). Also, the model result agrees with the Copernicus Atmosphere Monitoring Service (CAMS) model. The quantile regression in our model enables us to understand the importance of predictors for different NO₂ level estimations. Additionally, the uncertainty information reveals the extra potential exceedance of the World Health Organization (WHO) 2021 limit in some locations, which is undetectable by only point estimates. Meanwhile, the uncertainty quantification allows assessment of the model's robustness outside existing in-situ station measurements. It reveals challenges of NO₂ estimation over urban and mountainous areas where NO₂ is highly variable and heterogeneously distributed.</p>\u0000 </section>\u0000 </div>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2023JD040676","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142435354","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":"Assessment of Meteorological Drought in a Changing Environment: An Example in the Upper Yangtze River","authors":"Jiaju Shen,&nbsp;Hanbo Yang,&nbsp;Ziwei Liu,&nbsp;Changming Li,&nbsp;Sien Li,&nbsp;Yaokui Cui,&nbsp;Dawen Yang","doi":"10.1029/2024JD041019","DOIUrl":"https://doi.org/10.1029/2024JD041019","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <p>Recent studies have suggested that drought projections using Palmer drought severity index (PDSI) and standardized evapotranspiration precipitation index (SPEI) may overestimate drought severity. This overestimation occurs because the potential evapotranspiration (PET) calculations fail to consider the interactive effects of vegetation responses such as increased leaf area index (LAI) and constrained stomatal conductance, which are influenced by elevated atmospheric CO₂ concentrations ([CO₂]). To address this issue, our study replaced the traditional Penman-Monteith (PM) equation with a recently proposed PET equation that includes the effects of changing [CO₂] and LAI to assess droughts at monthly scale in the Upper Yangtze River basin, which experiences the vegetation greening. The findings indicated a consistent increasing trend in drought conditions with minimal discrepancy between the two equations over the historical period (1986–2017). This consistency arises because the water-saving effects of increased [CO₂] and the greening effects of rising LAI largely counterbalance each other. However, for the future period (2018–2100), projections using PM equation predicted an intensification of drought conditions. In contrast, the improved SPEI indicated no significant drought variations, and the improved PDSI suggested a wetting trend. This divergence can be attributed to the water-saving effects increasingly outweighing the greening effects, as PET shows a decreasing sensitivity to LAI with LAI increasing, but maintains a near-constant sensitivity to elevated [CO₂]. Consequently, the indices based on PM equation tend to overestimate future drought severity. Overall, this study demonstrates that the new PET estimation method is more capable of responding to the changing environment.</p>\u0000 </section>\u0000 </div>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142435714","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 Statistical Study of Polar Mesospheric Cloud Fronts in the Northern Hemisphere","authors":"Brentha Thurairajah,&nbsp;Chihoko Y. Cullens,&nbsp;V. Lynn Harvey,&nbsp;Cora E. Randall","doi":"10.1029/2024JD041502","DOIUrl":"https://doi.org/10.1029/2024JD041502","url":null,"abstract":"<p>Complex spatial structures in polar mesospheric cloud (PMC) images provide visual clues to the dynamics that occur in the summer mesosphere. In this study, we document one such structure, a PMC front, by analyzing PMC images in the northern hemisphere from the Cloud Imaging and Particle Size (CIPS) instrument onboard the aeronomy of ice in the mesosphere (AIM) satellite. A PMC front is defined as a sharp boundary that separates cloudy and mostly clear regions, and where the clouds at the front boundary are brighter than the clouds in the cloudy region. We explore the environment that supports the formation of PMC fronts using near-coincident temperature and water vapor observations from the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) satellite instrument. A comparison of PMC front locations to near-coincident temperature profiles reveals the presence of inversion layers at PMC altitudes. The adiabatic and superadiabatic topside lapse rates of these temperature inversions indicate that some of the identified inversion layers may have been formed by gravity wave (GW) dissipation. The structure of the squared buoyancy frequency profiles indicates a stable layer or thermal duct that can be associated with large-amplitude mesospheric inversion layers (MILs) that extend large distances. These inversion layers may be conducive to horizontal wave propagation. We hypothesize that ducted GWs may be a formation mechanism of PMC fronts.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142404569","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 Asian Dust on Cirrus Formation Over the Central Pacific: CALIOP- and CloudSat-Observation-Based Case Studies","authors":"Huijia Shen,&nbsp;Zhenping Yin,&nbsp;Yun He,&nbsp;Albert Ansmann,&nbsp;Yifan Zhan,&nbsp;Longlong Wang,&nbsp;Dongzhe Jing","doi":"10.1029/2024JD041265","DOIUrl":"https://doi.org/10.1029/2024JD041265","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <p>Cirrus clouds are of great importance to the global climate, with their net radiative forcing strongly dependent on the microphysical properties that are related to the ice-nucleating regime. However, the influence of long-range transport of dust on primary ice formation in cirrus clouds is limitedly understood, specifically over the clean remote ocean regions. Here, two case studies show that transpacific Asian dust can impact the ice formation of cirrus clouds over the central Pacific based on Cloud-Aerosol Lidar with Orthogonal Polarization and Cloud Profiling Radar (CPR, CloudSat) observations. One case shows a well-developed horizontally extended cirrus embedded in a pure dust layer, with an average dust-related ice-nucleating particle concentration (INPC) of 7 L⁻¹ and 96 L⁻¹ for an ice saturation ratio <i>S</i>_i of 1.15 and 1.25, respectively; ice crystal number concentration (ICNC) with diameters &gt;25 and 100 μm (denoted as <i>n</i>_{ice,25 μm} and <i>n</i>_{ice,100 μm}) are 64 L⁻¹ and 7 L⁻¹, respectively. Another case shows that cirrus clouds with a much smaller horizontal extent appeared in the vicinity of polluted dust, with an average INPC of 42–310 L⁻¹ for the typical higher <i>S</i>_i of 1.25–1.35 by considering a tenfold reduction of the ice nucleation efficiency of ice crystals; <i>n</i>_{ice,25 μm} and <i>n</i>_{ice,100 μm} are 168 L⁻¹ and 20 L⁻¹, respectively. The estimated INPC and ICNC values suggest the dominance of ice formation by dust-induced heterogeneous nucleation, proving that the long-range transport of dust toward the upper troposphere and the potential influence on cirrus formation over the central Pacific should be well considered in atmospheric models.</p>\u0000 </section>\u0000 </div>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142430037","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}