Journal of Geophysical Research: Atmospheres最新文献

{"title":"Global Model of Atmospheric Chlorate on Earth","authors":"Yuk-Chun Chan,&nbsp;Lyatt Jaeglé,&nbsp;Pedro Campuzano-Jost,&nbsp;David C. Catling,&nbsp;Vasile I. Furdui,&nbsp;W. Andrew Jackson,&nbsp;Jose L. Jimenez,&nbsp;Dongwook Kim,&nbsp;Becky Alexander","doi":"10.1029/2024JD042162","DOIUrl":"https://doi.org/10.1029/2024JD042162","url":null,"abstract":"<p>Naturally occurring chlorate (ClO₃⁻) has been observed on Earth and potentially plays important roles in hydrology and mineralogy on Mars. However, natural sources of chlorate are uncertain. Here, we quantify the importance of atmospheric sources of chlorate. We use GEOS-Chem, a global three-dimensional chemical transport model, to simulate the formation, photochemical loss, transport, and deposition of atmospheric chlorate on present-day Earth. We also develop a method to estimate the ¹⁷O-excess (∆¹⁷O) and the ³⁶Cl-to-total-Cl ratio (³⁶Cl/Cl) of atmospheric chlorate to interpret the observed isotopic composition of chlorate accumulated in desert soils. The model predicts that gas-phase chemistry can produce 15 Gg Cl year⁻¹ of chloric acid (HClO₃), which predominantly is taken up by aerosols to form particulate chlorate. Comparing the model with observations suggests that particulate chlorate undergoes chemical loss in the atmosphere, which controls the amount reaching Earth's surface. We show that the initial ∆¹⁷O that atmospheric chlorate acquires during formation would be erased rapidly in acidic aerosols due to the exchange of oxygen atoms with water. The analysis of ³⁶Cl/Cl does not preclude a partial stratospheric origin for chlorate deposits in the Atacama Desert. In Death Valley, aqueous-phase oxidation of oxychlorine species and anthropogenic activities potentially have greater influence. Our findings highlight the need for more observations of atmospheric chlorate and laboratory measurements of its reactivity in acidic conditions. Atmospheric chemistry should be considered in the future studies of the origin of chlorate on Mars.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 5","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD042162","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143534039","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":"Temporal Variations and Source Apportionment of Biomass Burning and Biogenic Organic Aerosols in the Pearl River Delta: Effects of the Monsoon, Plant Phenology, and Anthropogenic Activities","authors":"Lingxiao Lu,&nbsp;Buqing Xu,&nbsp;Bhagawati Kunwar,&nbsp;Ambarish Pokhrel,&nbsp;Kimitaka Kawamura,&nbsp;Gan Zhang","doi":"10.1029/2024JD042625","DOIUrl":"https://doi.org/10.1029/2024JD042625","url":null,"abstract":"<p>Biomass burning (BB) and biogenic emissions significantly influence the chemical compositions of organic aerosols (OAs). In this study, aerosol samples collected throughout the year from a regional receptor site in the Pearl River Delta (PRD) were analyzed for BB tracers, primary biological aerosol particle (PBAP) tracers, and biogenic secondary organic aerosol tracers. The BB aerosol concentrations were highest from November to January, and this was mainly attributed to domestic biomass burning in southern China. Biomass burning emissions in Southeast Asia affected the PRD through long-range transport between May and August. Two primary sugar concentration peaks, one in September and October and the other in March, may reflect regional plant phenology, and the constant concentrations for most of the year indicated regional PBAP background emissions. Concentration and correlation analyses indicated that the use of arabitol, erythritol, and inositol as PBAP tracers may not be appropriate because of strong interference by intensive BB emissions. Positive matrix factorization source apportionment showed that plant debris and fungal spores (46%) were the dominant contributors to BB and biogenic organic aerosols (BOAs) during the marine monsoon, but that BB (28%) was the most important contributor during the continental monsoon. The positive matrix factorization results agreed well with the molecular-level radiocarbon-based source apportionment results. Our work indicates that geographic and anthropogenic factors, including the monsoon, plant phenology, and anthropogenic activities, combine to control the chemical compositions of BB and BOAs in the PRD.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 5","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143533575","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":"Decoupling Temperature and Light Effects on Terpene Emissions From Subtropical Eucalyptus: Insights From Controlled Field Experiments","authors":"Jianqiang Zeng,&nbsp;Yanli Zhang,&nbsp;Weihua Pang,&nbsp;Haofan Ran,&nbsp;Zhaobin Mu,&nbsp;Hao Guo,&nbsp;Yuting Lu,&nbsp;Wei Song,&nbsp;Xinming Wang","doi":"10.1029/2024JD042616","DOIUrl":"https://doi.org/10.1029/2024JD042616","url":null,"abstract":"<p>Emissions of biogenic volatile organic compounds (BVOCs) from plants are significantly influenced by both temperature and light, yet the individual contribution of these factors, particularly for emissions of monoterpenes (MTs) and sesquiterpenes (SQTs) from tropical and subtropical plant species, remain poorly quantified due to their covariant effects. In this study, we conducted in situ and controlled field experiments on subtropical <i>Eucalyptus</i> trees using a portable LI-6800 photosynthesis system to isolate and quantify the temperature and light responses of major MTs. Additionally, we qualitatively assessed the light dependence of minor MTs and SQTs through dynamic chamber measurements. Our results revealed distinct light dependence across different compounds: β-ocimenes were fully light-dependent but exhibited unexpected suppression under high light conditions, whereas α-pinene and 1,8-cineole were light-independent. Temperature response experiments indicated that the temperature sensitivity (<i>β</i>) for light-dependent β-ocimenes (0.095 K⁻¹) and light-independent α-pinene (0.071 K⁻¹) and 1,8-cineole (0.102 K⁻¹) were similar to the model value (0.1 K⁻¹), but significantly lower than previously reported values from uncontrolled tropical measurements (0.2 K⁻¹), suggesting an influence of light on observed temperature sensitivity. Chamber-based results revealed that acyclic MTs and α-phellandrene were fully light-dependent, similar to β-ocimenes, while cyclic MTs and the SQT α-longipinene were light-independent and followed an exponential temperature function. Other SQTs exhibited partial light-dependence and would need a hybrid modeling approach. These results provide valuable insights into the emission mechanisms of various terpene types, with important implications for enhancing predictive models of BVOC emissions.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 5","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143533586","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 New GPM-DPR Algorithm to Estimate Snowfall in Mountain Regions","authors":"A. Bertoncini,&nbsp;J. M. Thériault,&nbsp;J. W. Pomeroy","doi":"10.1029/2024JD041481","DOIUrl":"https://doi.org/10.1029/2024JD041481","url":null,"abstract":"<p>Reliable precipitation forcing is essential for calculating the water balance and other hydrological variables. However, satellite precipitation is often the only forcing available to run hydrological models in data-scarce regions compromising hydrological calculations. The Integrated Multi-satellitE Retrievals for GPM (IMERG) product estimates precipitation from passive microwave and infrared satellites, which are intercalibrated based on Global Precipitation Measurement (GPM)'s Dual-frequency Precipitation Radar (DPR) and GPM Microwave Image (GMI) instruments. GPM-DPR radar algorithms have a limited consideration of particle size distribution (PSD), attenuation correction, and ground clutter, resulting in snowfall estimation degradation especially in mountain regions. This study aims to improve satellite radar snowfall for this situation. Nearly 2 years (2019–2022) of aloft precipitation concentration, surface hydrometeor size, number and fall velocity, and surface precipitation rate from a Canadian Rockies high-elevation site and collocated GPM-DPR reflectivities were used to develop a new snowfall estimation algorithm. Snowfall estimates using the new algorithm and measured GPM-DPR reflectivities were compared to other GPM-DPR-based products, including the combined radar-radiometer algorithm (CORRA), which was employed to intercalibrate IMERG. Snowfall rates estimated with measured Ka reflectivities, and from CORRA were compared to Micro Rain Radar-2 (MRR-2) observations and had correlation, bias, and RMSE of 0.58 and 0.07, 0.43, and −0.38 mm hr⁻¹, and 0.83 and 0.85 mm hr⁻¹, respectively. Predictions using measured Ka reflectivity suggest that enhanced satellite radar snowfall estimates can be achieved using a simple measured reflectivity algorithm. These improved snowfall estimates can be adopted to intercalibrate IMERG in cold mountain regions, thereby improving precipitation estimates.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 5","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD041481","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143533387","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":"The Impact of the 2023 Canadian Forest Fires on Air Quality in Southern Ontario","authors":"Victoria A. Flood,&nbsp;Kimberly Strong,&nbsp;Cynthia H. Whaley,&nbsp;Jack Chen,&nbsp;Debra Wunch,&nbsp;James R. Drummond,&nbsp;Orfeo Colebatch,&nbsp;Lawson Gillespie,&nbsp;Nasrin Mostafavi Pak","doi":"10.1029/2024JD042254","DOIUrl":"https://doi.org/10.1029/2024JD042254","url":null,"abstract":"<p>The record-breaking 2023 Canadian wildfire season had large-scale burning that resulted in wide-reaching long-range transport of smoke plumes and their associated trace gases. This paper examines three events (May 16-23, June 3-9 and June 17-30, 2023) during which the composition of smoke was measured over Toronto and Egbert, Ontario. Tropospheric columns (0–10 km) of CO, C₂H₆, CH₃OH, HCN, HCOOH, NH₃ and O₃ were measured using high-resolution Fourier transform infrared spectrometers. Coincident enhancements of CO and other gases during the events were used to calculate enhancement ratios. Correlations with CO were observed for C₂H₆, CH₃OH, HCN and HCOOH, but not for NH₃ and O₃. Plume transport was investigated with the Hybrid Single-Particle Lagrangian Integrated Trajectory model, the GEM-MACH-FireWork (GM-FW) air quality model, and Measurements of Pollution in the Troposphere (MOPITT) CO satellite data. Additional measurements examined were surface CO, O₃, and PM_2.5, plume height from a Mini Micro Pulse Lidar, and EM27/SUN XCO columns. GM-FW model output was compared with ground-based surface and 0–10 km column measurements, and MOPITT CO maps. Over the 2023 forest fire season (May-September), the model underestimated background tropospheric columns of CO, NH₃ and O₃, but generally overestimated enhancements during smoke events. Relative to surface in situ measurements, GM-FW seasonal averages overestimated CO and underestimated O₃ (which was not generally enhanced during smoke events), while PM_2.5 fluctuated between a positive and negative bias. Compared to MOPITT, the GM-FW event-averaged CO columns appropriately represent plume dispersion across the country, with some offsets on the scale of the ground-based locations that are consistent with the discussed findings.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 5","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD042254","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143534040","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":"Aircraft-Based Observation of Mineral Dust Particles Over the Western North Pacific in Summer Using a Complex Amplitude Sensor","authors":"S. Ohata,&nbsp;N. Moteki,&nbsp;K. Adachi,&nbsp;Y. Tobo,&nbsp;H. Matsui,&nbsp;K. Kita,&nbsp;T. Mori,&nbsp;M. Koike","doi":"10.1029/2024JD043063","DOIUrl":"https://doi.org/10.1029/2024JD043063","url":null,"abstract":"<p>Mineral dust accounts for a significant fraction of the atmospheric aerosol burden, impacting climate through its interactions with radiation and clouds. However, limited observations of dust particles in the free troposphere hinder our understanding of its spatial distribution and climatic impacts. In this study, aerosols were collected on filters using aircraft over the western North Pacific at 0.2–8 km altitudes in summer 2022. Individual water-insoluble particles dispersed in water were analyzed using a complex amplitude sensor (CAS), which enabled classifying particle type, sizing, and counting from the particle's complex amplitude data. During the eight observation flights, the number and mass concentrations of dust were 1.2 ± 1.0 cm⁻³ and 0.6 ± 0.4 μg m⁻³ (mean ± 1σ), respectively, in the 0.3–2.5 μm diameter range, which were 2–3 orders of magnitude lower than previously reported values near the major dust sources in East Asia. A comparison with the total aerosol data from an optical particle counter onboard aircraft suggested that dust dominated aerosols larger than 0.8 μm, consistent with electron microscopy analyses. The observed dust size distributions implied more efficient removal of larger dust during transport. Since our samples were collected at −18°C to 21°C, the free tropospheric dust could contribute to ice formation in clouds. Our observation using the CAS revealed microphysical properties of dust over the western North Pacific when no distinct Asian dust events were observed near the ground, aiding in the validation of models that assess the climatic impacts of dust.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 5","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD043063","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143533584","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":"Northward Propagating Versus Non-Propagating BSISO Over South Asia: Horizontal Advection Driven Moisture Mode Within a Vertically Sheared Background","authors":"Sambrita Ghatak,&nbsp;Jai Sukhatme","doi":"10.1029/2024JD041413","DOIUrl":"https://doi.org/10.1029/2024JD041413","url":null,"abstract":"<p>The Boreal Summer Intraseasonal Oscillation (BSISO) is a pronounced mode of tropical variability. Here, we identify two types of BSISO events, one which propagates northward over South Asia from the equatorial Indian Ocean (EIO), and the other which doesn't. Contrasting their behavior shows that the northward propagation occurs in multiple stages after convection is initiated over the EIO. First, the convection moves into the southern Arabian Sea (AS) due to moistening of the free troposphere via horizontal BSISO anomalous winds acting on the background moisture distribution, and forms a northwest-southeast (NW-SE) oriented convection band. Subsequently, in the presence of an easterly vertical shear of monsoon winds and meridional gradient of anomalous vertical velocity, a NW-SE oriented tilting term is generated that results in a tilted gyre north of the existing convective anomaly and south-easterly BSISO winds over the South Asian landmass. In the second stage, these winds tap the ambient north-westward moisture gradient and help move the convection further north over land. Moreover, the background winds advect anomalous moisture to initiate convection over the Bay of Bengal. For the non-propagating events, though a Rossby gyre results as a response to the nascent EIO convection, it is smaller, thus the BSISO advection of background moisture is weaker and does not initiate convection over the southern AS. In turn, the meridional gradient of the anomalous vertical velocity is weak, and the background vertical shear cannot generate sufficient tilting over the northern AS. Therefore, the convective wind response stalls, and large-scale convection does not propagate north of 15N. Thus, free-tropospheric moisture advection and vortex tilting due to the background vertical shear work together for robust northward propagation of the BSISO, and strong BSISO easterlies over the southern AS is critical behind this propagation.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 5","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143533585","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":"Toward Dynamical Annual to Decadal Climate Prediction Using the IAP-CAS Model","authors":"Yao Tang,&nbsp;Qing Bao,&nbsp;Xiaofei Wu,&nbsp;Tao Zhu,&nbsp;Bian He,&nbsp;Yimin Liu,&nbsp;Guoxiong Wu,&nbsp;Siyuan Zhou,&nbsp;Yangke Liu,&nbsp;Ankang Qu","doi":"10.1029/2024JD042580","DOIUrl":"https://doi.org/10.1029/2024JD042580","url":null,"abstract":"<p>Annual to decadal (A2D) climate prediction provides key insights for public policy and individual decision-making over the next 1–10 years, but most current dynamical models exhibit limited skill at the A2D scale. To address this challenge, the IAP-CAS A2D dynamical ensemble climate prediction system has been developed by expanding the existing operational sub-seasonal to seasonal (S2S) prediction system approved by the WMO/WWRP S2S panel. Using a full-field atmosphere-ocean initialization experiment which covers the period from 1981 to 2015, several key findings are revealed: First, the model demonstrates significant positive skill for regional surface temperature predictions globally, except for the North Atlantic, likely due to the initial shock. Despite this, the model effectively captures the global mean surface temperature warming trend. Second, the model exhibits relatively high predictability for the Pacific Decadal Oscillation (PDO), with correlation skill up to 3 years, comparable to the sixth Coupled Model Intercomparison Project Decadal Climate Prediction Project multi-model ensemble mean. The spread-error ratios close to 1 in the PDO predictions indicate high reliability. Additionally, the model shows significant skill in predicting the El Niño-Southern Oscillation (ENSO) for up to 1 year, comparable to leading seasonal dynamical prediction models. Further analysis reveals an established teleconnection between ENSO and the North Pacific atmosphere in the IAP-CAS model, likely underpinning the PDO predictive skill at forecast year 1. This study also assesses the effect of initialization by comparing initialized hindcast data with uninitialized historical simulations.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 5","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143533588","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":"3D Radio Frequency Mapping and Polarization Observations Show Lightning Flashes Were Ignited by Cosmic-Ray Showers","authors":"Xuan-Min Shao,&nbsp;Daniel P. Jensen,&nbsp;Cheng Ho,&nbsp;Michael P. Caffrey,&nbsp;Eric Y. Raby,&nbsp;Paul S. Graham,&nbsp;W. Brian Haynes,&nbsp;William G. Blaine","doi":"10.1029/2024JD042549","DOIUrl":"https://doi.org/10.1029/2024JD042549","url":null,"abstract":"<p>Previous 2D radio frequency interferometric observations showed that lightning is commonly started with a positive fast discharge (+FD) before a normal negative leader continues from the origin of the +FD to the ensuing lightning flash. However, the inception and development of the +FD cannot be convincingly explained by existing discharge theories. With our new 3D broadband interferometric mapping and polarization system, we observed that the +FD was sometimes followed by an even faster and more extensive negative discharge (−FD) that propagated backward and overshoot the origin by a few hundred meters, as reported by an earlier 2D study. Surprisingly, the signal polarization, which measures the orientation of the discharge current, systematically slanted from the discharge propagation direction and rotated between the two opposite discharges, showing the +FD and −FD were driven by other storm-independent factors in addition to the storm electric field, or otherwise all would align in the same direction. Assuming a cosmic-ray shower (CRS) piercing through the cloud immediately before the +FD/−FD discharge, we found that their path is consistent with a pre-ionized path by the CRS, and the polarizations for the two opposite discharges are consistent with the respective deflected trajectories of high-energy positrons and electrons in the geomagnetic and an electric field. We further analyzed the more commonly observed +FD and showed that it is consistent with the CRS interpretation, suggesting these flashes in thunderstorms were ignited by cosmic-ray showers.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 5","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD042549","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143533583","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":"Co-Occurring Atmospheric Features and Their Contributions to Precipitation Extremes","authors":"Wei-Ming Tsai,&nbsp;Suqin Duan,&nbsp;Travis A. O’Brien,&nbsp;Jennifer L. Catto,&nbsp;Paul A. Ullrich,&nbsp;Yang Zhou,&nbsp;L. Ruby Leung,&nbsp;Zhe Feng,&nbsp;William R. Boos,&nbsp;D. L. Suhas,&nbsp;Fiaz Ahmed,&nbsp;J. David Neelin","doi":"10.1029/2024JD041687","DOIUrl":"https://doi.org/10.1029/2024JD041687","url":null,"abstract":"<p>Object-based identification algorithms for atmospheric features are commonly utilized to attribute global precipitation. This study employs a systematic approach to examine feature co-occurrences and their relationships to mean and extreme precipitation. Four features are identified using existing data sets for atmospheric rivers (ARs), mesoscale convective systems (MCSs), low-pressure systems (LPSs), and fronts (FTs). Often, a single atmospheric phenomenon satisfies the criteria set by multiple feature identification algorithms, yielding an association between precipitation and multiple features. Over the extra-tropics, the number of features attributed to a single event typically increases with precipitation intensity. Over two-thirds of the precipitation is from co-occurring features, with a considerable fraction related to AR-FT co-occurrences. Over the tropics, about one-quarter of precipitation is associated with co-occurring features, with LPS-MCS co-occurrences contributing substantially in monsoon regions. MCSs are the leading single-feature contributors over tropical land and oceans. In the extra-tropics, FTs, ARs, and their co-occurrences account for over half of the total precipitation over oceans. AR-FT-MCS and FT-MCS co-occurrences contribute to extremes (precipitation exceeding the 95th percentile) over both oceans (over 30%) and land (over 20%). Any combination of features involving MCSs shows a larger contribution to high percentiles of precipitation intensity. A case analysis indicates that AR-FT-MCS co-occurrences exhibit convective instability and deep vertical motion, suggesting that the feature trackers and reanalysis are capturing physics relevant to both convective and frontal systems. The results here emphasize the need for simultaneous identifications of multiple features when attributing precipitation to atmospheric phenomena.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 5","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD041687","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143513570","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}