Journal of Geophysical Research: Atmospheres最新文献

{"title":"Variations in Tropical Cyclone Size and Rainfall Patterns Based on Synoptic-Scale Moisture Environments in the North Atlantic","authors":"K. D. Addington,&nbsp;S. E. Zick,&nbsp;K. M. Wood,&nbsp;C. J. Matyas,&nbsp;K. Berislavich","doi":"10.1029/2024JD043135","DOIUrl":"https://doi.org/10.1029/2024JD043135","url":null,"abstract":"<p>Prior research has shown that tropical cyclone (TC) size, which is integral in determining the spatial extent of TC impacts, is influenced by environmental wind shear and the overall moisture environment. This study considers North Atlantic TCs located within low to moderate wind shear and at least 100 km from major landmasses. An empirical orthogonal function (EOF) analysis is applied to distinguish moisture environments based on the spatial pattern of total column water vapor surrounding the TC. Using these EOF patterns, four separate categories (groups) are created. Principal component scores indicate the TC samples most contributing to each EOF pattern and ultimately determine the cases in each group. TC structural differences among the groups are compared using size metrics based on the wind and precipitation fields and shape metrics based on the precipitation field. These metrics are considered across a 48-hr window centered on the sample times evaluated in the EOF analysis. There are no statistically significant differences in the TC wind field size, but TCs with abundant moisture to the southeast have larger rain areas with more outer rainbands. TCs in a dry environment or with dry air southeast of the TC center have generally smaller rain areas and less closed rainbands than TCs with moisture to the southeast. Future work will investigate the physical processes contributing to these spatial differences in precipitation.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 10","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD043135","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144085128","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":"Anthropogenic Carbon Monoxide Emissions During 2014–2020 in China Constrained by In Situ Ground Observations","authors":"Mengwei Jia,&nbsp;Fei Jiang,&nbsp;Nikolaos Evangeliou,&nbsp;Sabine Eckhardt,&nbsp;Andreas Stohl,&nbsp;Xin Huang,&nbsp;Yang Shen,&nbsp;Shuzhuang Feng,&nbsp;Wei He,&nbsp;Jun Wang,&nbsp;Hengmao Wang,&nbsp;Mousong Wu,&nbsp;Weimin Ju,&nbsp;Aijun Ding","doi":"10.1029/2024JD042371","DOIUrl":"https://doi.org/10.1029/2024JD042371","url":null,"abstract":"<p>China has been actively reducing anthropogenic air pollutant emissions over the past decade and is about to embark on the next phase of air quality management. Carbon monoxide (CO) is an ideal indicator of primary pollutants from combustion sources. A comprehensive assessment of the current situation of anthropogenic CO emissions can inform the implementation of future reduction policies. This work aims to determine the changes of anthropogenic CO emissions in mainland China from 2014 to 2020 at 0.2° × 0.2° spatial resolution. Hourly CO observations from over 1,600 national control sites were combined with Lagrangian dispersion modeling and multisectoral emission inventories in a Bayesian inversion framework, to determine monthly CO emissions. From 2014 to 2020, the average annual anthropogenic CO emission in mainland China was 473.6 ± 117.2 Tg a⁻¹, which is 2.5 times higher than the prior emission. Northwest China stands out as the most underestimated region with a relative difference of an astonishing 6.3 times between prior and posterior emissions. The emissions generally decreased by 32.0% from 2014 to 2020, but with a clear rebound in 2017 and 2018, and Yunnan in the southwest and Xinjiang in the northwest are the most pronounced rebound provinces. Optimizing the management of direct emissions in the future requires not only focusing on key urban agglomerations but also strengthening controls in remote provinces.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 10","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144085129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Impacts of Gravity Waves and Wind Shear on the Lifecycle of Cirrus Clouds in the Tropical Tropopause Layer","authors":"E. J. Jensen,&nbsp;R. Ueyama,&nbsp;L. Pfister,&nbsp;R. L. Atlas","doi":"10.1029/2024JD042308","DOIUrl":"https://doi.org/10.1029/2024JD042308","url":null,"abstract":"&lt;p&gt;In this study, we use two-dimensional simulations to investigate the impacts of wind shear and gravity wave temperature fluctuations on the lifecycle of thin cirrus clouds in the tropical tropopause layer (TTL). Initial conditions for the simulations are based on a case study from high-altitude aircraft observations of a narrow layer of abundant small ice crystals just after a homogeneous freezing ice nucleation event. Analysis of high-resolution radiosonde observations shows that the TTL is a region where strong wind shear (often 10–&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mn&gt;20&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;3&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $20times 1{0}^{-3}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msup&gt;\u0000 &lt;mi&gt;s&lt;/mi&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 &lt;annotation&gt; ${mathrm{s}}^{-1}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;) prevails. We find that the strong TTL wind shear alters the structure of TTL cirrus, accelerates the reduction in ice concentration, and shortens the cloud lifetimes. The typically thin laminar structure of the clouds indicated by lidar observations is likely a direct result of the strong wind shear in the TTL. Gravity-wave temperature fluctuations further accelerate the reduction in ice concentration as the clouds evolve. The simulations show that TTL cirrus lifetimes decrease with decreasing initial ice concentration, decreasing initial supersaturation and increasing turbulent diffusivity. Based on simulations with observed TTL wind shear, wave properties, and initial cloud properties, we show that TTL cirrus lifetimes are typically less than 1 day. Clouds produced by heterogeneous nucleation, with lower initial ice concentration and supersaturation, will have even shorter lifetimes. Persistence of TTL cirrus for multiple days would require sustained upward vertical wind with an amplitude of at least &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;≃&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $simeq $&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;0.2 cm &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msup&gt;\u0000 &lt;mi&gt;s&lt;/mi&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 ","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 10","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD042308","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144074341","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":"Compound Dry-Dusty Air Intrusions During the Genesis of Tropical Storm Kate (2021): Observations From the CPEX-AW Field Campaign and Coupled Modeling","authors":"Edoardo Mazza,&nbsp;Shuyi S. Chen","doi":"10.1029/2024JD042653","DOIUrl":"https://doi.org/10.1029/2024JD042653","url":null,"abstract":"<p>The influence of the Saharan air layer (SAL) on developing tropical cyclones (TCs) involves complex interactions between dynamic, thermodynamic, and cloud microphysical processes and thus remains highly challenging to forecast. This study leverages a unique set of in situ aircraft observations from the NASA Convective Processes – Aerosols and Winds (CPEX-AW) field campaign and a high-resolution, fully coupled atmosphere-wave-ocean model simulation to examine the complexity of compound dry-dusty air intrusions during the genesis of Tropical Storm (TS) Kate (2021). The suite of CPEX-AW observations, featuring a multifrequency lidar, a precipitation radar and GPS dropsondes, provides a unique perspective of the interplay between multiple air masses in the environment surrounding TS Kate. We complement CPEX-AW observations with atmospheric tracers from the high-resolution coupled-model simulation to better understand the origins and transport of these air masses and their impacts on TS Kate. Two distinct intrusions are observed: one within the precursor easterly wave and one during the Tropical Depression (TD) stage. Within the precursor wave, low-<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>θ</mi>\u0000 <mi>e</mi>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${theta }_{e}$</annotation>\u0000 </semantics></math> marine air associated with subsidence within the subtropical high undercuts the SAL as both air masses are entrained along two pathways: (a) lateral entrainment following the wave-relative inflow and (b) vertical entrainment downward into the boundary layer and subsequently upward within deep convection. Later, mid-tropospheric dry air from the subtropical high merges with the remnant SAL, resulting in strong radial ventilation of the TD above the boundary layer likely limiting any further intensification.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 10","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144074340","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":"Optimizing Source Apportionment of OVOCs With Machine Learning-Enhanced Photochemical Models","authors":"Y. Zou,&nbsp;X. H. Guan,&nbsp;R. M. Flores,&nbsp;X. L. Yan,&nbsp;X. J. Liang,&nbsp;L. Y. Fan,&nbsp;T. Deng,&nbsp;X. J. Deng,&nbsp;D. Q. Ye,&nbsp;P. V. Doskey","doi":"10.1029/2024JD043080","DOIUrl":"https://doi.org/10.1029/2024JD043080","url":null,"abstract":"<p>The photochemical age parameterization model is widely used to analyze primary and secondary sources of oxygenated volatile organic compounds (OVOCs). However, a key challenge lies in selecting appropriate tracers chemicals used to estimate contributions from different emission sources. Accurate tracer selection is crucial for improving source apportionment accuracy, yet it is often constrained by local emission inventories and may not fully capture rapid atmospheric chemical transformations introducing uncertainty in OVOC apportionment. This study presents a novel approach integrating eight different machine learning methods to identify optimal tracers for OVOCs during extreme summer temperatures (experimental group) and average spring temperatures (control group). Our results demonstrated notable differences in tracer effectiveness between these two groups. In the spring, toluene and carbon monoxide (CO) were identified as the most effective tracers for OVOCs with high and low reactivity, respectively. In the summer, acetylene or CO were better suited for moderate and low reactivity OVOCs. By incorporating machine learning for tracer selection, we significantly improved the accuracy of the photochemical age parameterization model. The machine learning outputs correlated well with the model's performance particularly in terms of fitting accuracy of OVOCs. However, extremely high temperatures during summer disrupted the usual patterns of OVOC production and removal, which led to inconsistencies in matching high reactivity OVOCs with their tracers. Future research involves collecting more data on OVOC behavior under high-temperature conditions and applying Fourier transformation techniques. This will help in identifying characteristic patterns and improving the dynamic accuracy of our model.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 10","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144074274","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":"Wind Diversity Trends in the Lower Stratosphere Analyzed From Radiosondes Launched in the Western Hemisphere","authors":"Tristan K. Schuler,&nbsp;Craig Motell","doi":"10.1029/2024JD042770","DOIUrl":"https://doi.org/10.1029/2024JD042770","url":null,"abstract":"<p>High altitude balloons (HABs) with altitude control capability can leverage varying wind patterns at different altitudes to perform station-keeping maneuvers and other complex trajectories. At minimum, effective station-keeping of HABs requires opposing winds at two different altitudes. Wind diversity trends in the lower stratosphere are highly dependent on geographic area, altitude range, and time of year. To investigate historical wind diversity trends, we analyzed over 1.25 million radiosonde sounding launches from the Western Hemisphere between 2012 and 2023. Radiosondes provide higher vertical resolution than standard reanalysis forecasts, which often underestimate wind diversity due to smoothing during the global assimilation process. Overall, our analysis reveals that higher opposing winds probabilities tend to follow the summer months for each hemisphere, respectively, with the exception being the tropics, which typically have strong opposing wind probabilities year round. Similarly, the summer months also tend to have a higher probability of calm (“light-and-variable”) winds, although in a smaller latitudinal and altitude bands than opposing winds. Transition months, typically in the spring and fall, have the highest variation in opposing wind probabilities from decadal means, while the summer and winter months have more predictable regional trends. These wind diversity trends can assist with developing trajectories and mission planning for high altitude platforms.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 10","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144074377","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":"Spatiotemporal Evolution Patterns of Global Actual Evapotranspiration and Its Influencing Factors","authors":"Haoyu Jin,&nbsp;Ke Zhang,&nbsp;Yiming Huang,&nbsp;Pengfei Zhang,&nbsp;Guoyan Liu,&nbsp;Moyang Liu","doi":"10.1029/2024JD042515","DOIUrl":"https://doi.org/10.1029/2024JD042515","url":null,"abstract":"<p>Understanding the spatiotemporal dynamics of actual evapotranspiration (AET) and its drivers is critical for addressing climate change and ensuring ecosystem sustainability. Here, we analyzed global AET trends from 2001 to 2019 and assessed the relative contributions of six key influencing factors. Our findings reveal that AET exhibits a significant positive trend across 31.6% of the global land surface, predominantly in the Amazon Plain and the Loess Plateau of China, whereas a significant negative trend is observed over 5.2% of the land area, concentrated in eastern Brazil and southern Africa. The normalized difference vegetation index (NDVI) showed the strongest partial correlation with AET, influencing 26.6% of the global land area. Multiple linear regression (MLR) analysis indicates that precipitation exerts the greatest influence on AET in 39.9% of the world, followed by wind speed (WS) at 37.9%, while soil moisture (SM) is the dominant factor in only 0.2% of the global land area. Notably, WS drives 23.5% of the observed AET trends, whereas precipitation contributes most to trends in just 8.6% of the land area. Among the factors evaluated, NDVI emerges as the primary driver of AET changes, followed by precipitation, while surface net solar radiation (SNSR) has the weakest influence. These insights advance the understanding of global AET's spatiotemporal evolution and its driving mechanisms, offering a foundation for devising adaptive strategies to mitigate climate change impacts and enhance ecosystem resilience.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 10","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144074426","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":"Investigating the Relative Roles of INPs and CCN in a Simulated Thunderstorm Using a New Immersion Freezing Algorithm","authors":"Tobias I. D. Ross,&nbsp;Sonia Lasher-Trapp","doi":"10.1029/2024JD042592","DOIUrl":"https://doi.org/10.1029/2024JD042592","url":null,"abstract":"<p>Microphysical processes in deep convective clouds are sensitive to the number concentrations of cloud condensation nuclei (CCN) and ice nucleating particles (INPs), but the effects of INPs are less studied. Modeling studies investigating the effects of INPs and/or CCN on deep convection typically retain a volume-dependent raindrop freezing relation. The resulting neglect of aerosol accumulation in raindrops via drop collisions has likely produced unrealistic storm responses to INPs in past studies. To address this deficiency, a new immersion freezing algorithm was developed and embedded in a bulk microphysics scheme that freezes both cloud drops and raindrops using the same immersion freezing INP (IF-INP) activity spectrum based on measurements. Multiple idealized simulations of a single case of deep convection observed during the Clouds, Aerosols, and Complex Terrain Interactions (CACTI) field campaign were conducted, with microphysical differences produced by independently altering IF-INP temperature dependencies and CCN number concentrations from their observed values. Surface precipitation in all simulations resulted almost exclusively from riming graupel that melted upon descending to the surface. Rainfall and cold pools were substantially and systematically weakened with increased CCN due to decreased graupel riming rates but were relatively insensitive to variations in the magnitude and slope of IF-INP spectra due to compensating depletion of supercooled liquid water. These compensating processes were a consequence of the accumulation of IF-INPs in raindrops, encouraging caution in studying IF-INP effects upon thunderstorms using traditional volume-dependent drop freezing relationships.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 10","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD042592","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144074308","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":"Observed Downdrafts and Ventilation During the Rapid Intensity Changes of Hurricane Delta (2020)","authors":"Nicholas E. Johnson,&nbsp;Brian H. Tang,&nbsp;Kristen L. Corbosiero,&nbsp;Jonathan R. Moskaitis","doi":"10.1029/2024JD042915","DOIUrl":"https://doi.org/10.1029/2024JD042915","url":null,"abstract":"<p>This study examines downdrafts and downdraft ventilation, and their effects on Hurricane Delta (2020). Delta experienced rapid intensification (RI) before abruptly weakening before making landfall. Two sampling periods by reconnaissance aircraft provided observations during RI and the subsequent rapid weakening, giving an opportunity to study the downdraft evolution and compare these two periods. Across both sampling periods, the vertical wind shear increased, causing the vortex to tilt and exposing Delta's inner core to the surrounding environment. The increased shear provided a pathway for downdraft ventilation, the transport of low-equivalent potential temperature <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mfenced>\u0000 <msub>\u0000 <mi>θ</mi>\u0000 <mi>e</mi>\u0000 </msub>\u0000 </mfenced>\u0000 </mrow>\u0000 <annotation> $left({theta }_{e}right)$</annotation>\u0000 </semantics></math> air aloft into the boundary layer via downdrafts. Aircraft Doppler radar measured intense, deep downdrafts toward the end of the RI period; however, minimal downdraft ventilation was observed. After peak intensity, during the weakening period, downdraft ventilation was more prevalent with moderate to intense downdrafts and low-<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>θ</mi>\u0000 <mi>e</mi>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${theta }_{e}$</annotation>\u0000 </semantics></math> air concentrated on the left-of-tilt side of the storm. The observations show that as Delta weakened, the inner core became diluted with low-<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>θ</mi>\u0000 <mi>e</mi>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${theta }_{e}$</annotation>\u0000 </semantics></math> air from downdraft ventilation and the convection was limited to the downtilt and left-of-tilt regions of the storm. These findings are consistent with previous idealized and real-case modeling studies that have shown downdraft ventilation weakens tropical cyclones and degrades their structure. Additionally, the location of the downdraft ventilation observations relative to the vortex tilt and shear directions agree with previous modeling studies. More broadly, observations of the downdraft structure and diagnostics of downdraft ventilation may provide cues of subsequent intensity change in sheared storms.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 10","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144074309","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":"Arctic Atmospheric Rivers in a Changing Climate and the Impacts on Sea Ice","authors":"Rudradutt Thaker,&nbsp;Stephen J. Vavrus,&nbsp;Christine A. Shields,&nbsp;Alice K. DuVivier,&nbsp;Michelle Maclennan,&nbsp;Marika M. Holland,&nbsp;Laura Landrum","doi":"10.1029/2024JD042521","DOIUrl":"https://doi.org/10.1029/2024JD042521","url":null,"abstract":"<p>Atmospheric rivers (ARs) transport heat and moisture from lower latitudes to the Arctic, contributing to sea ice loss. As climate warming and sea ice decline continue, understanding how Arctic ARs evolve is essential. While studies suggest an increase in Arctic ARs and storms, a comprehensive understanding of their changing behavior, seasonal patterns, and sea ice impacts remains incomplete. This study investigates the changing dynamics of Arctic ARs in response to a warming climate, examining the drivers of these changes and their impact on sea ice. Using the Community Earth System Model, Version 2 (CESM2), we find CESM2 effectively simulates Arctic ARs compared to ERA5. To analyze ARs under different climate conditions, we apply three detection methods: using present climate thresholds, scaling thresholds with projected future moisture changes, and calculating unique thresholds for each decade. Our results show increased AR frequency and intensity in the future, with changes strongly influenced by the chosen AR definition. Depending on the method, we find that AR frequency increases range from 30%–50% up to 400%, or even show decreases in some regions. During fall and winter, the North Atlantic experiences increased AR frequency, while more intense ARs occur in the North Pacific during summer. We also explore the effects of future ARs on sea ice, finding a net increase in sea ice loss, particularly in winter and spring. The extent of sea ice loss is highly sensitive to the AR detection method used.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 10","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD042521","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144074352","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}