Journal of Geophysical Research: Atmospheres最新文献

{"title":"Synoptic Air Mass Controls on Global and Regional Precipitation","authors":"Omon A. Obarein,&nbsp;Cameron C. Lee","doi":"10.1029/2025JD043370","DOIUrl":"https://doi.org/10.1029/2025JD043370","url":null,"abstract":"<p>Despite the complexity of the physical mechanisms behind precipitation, many studies linking precipitation to weather types or atmospheric circulation focus on a single variable, oversimplifying the interactions involved. An alternative approach to examining precipitation involves the use of synoptic air masses, which provide a multivariate perspective. The gridded weather typing classification (GWTC-2) is a synoptic weather typing and air mass classification scheme that captures the holistic nature of weather at any given time and location. This study examined the association between precipitation and GWTC-2 air masses (AMs) on regional to global scales—marking the first use of the GWTC-2 AMs in precipitation studies. Although regional differences exist, land precipitation is better modulated by AMs than oceanic precipitation. There is a noticeably weaker association between AMs and tropical precipitation than extratropical precipitation, with extratropical regions showing up to 60% of summer precipitation variability explained. Regarding individual air mass influences, humid warm AMs show a surprisingly poor correlation with land precipitation, likely because water vapor does not increase linearly with increasing land temperatures. Also, compared to the other two humid AMs, humid cool AMs contribute five times more precipitation in deserts. More interestingly, the frontal AMs, defined to capture migrating extratropical cyclones, are strongly associated with tropical precipitation and capture the West African monsoon remarkably well. The association between GWTC-2 AMs and precipitation has potential applicability in ensemble precipitation forecasting and downscaling GCM simulations of daily precipitation.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 9","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025JD043370","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143932370","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":"Effect of Different Sources and Meteorological Processes on the Variability of VOC Composition in a Metropolitan City of Western India During Summer Season","authors":"L. K. Sahu,&nbsp;Mansi Gupta,&nbsp;Nidhi Tripathi,&nbsp;Ravi Yadav,&nbsp;Tanzil Gaffar Malik,&nbsp;Mizuo Kajino","doi":"10.1029/2024JD040867","DOIUrl":"https://doi.org/10.1029/2024JD040867","url":null,"abstract":"<p>High time- and mass-resolution measurements of volatile organic compounds (VOCs) using proton-transfer-reaction-time of flight-mass spectrometry were conducted in Ahmedabad metropolitan city in India during the summer (April–May) of 2014. The concentrations of aromatic VOCs were lower than in winter (January 2014), whereas acetaldehyde and acetone levels were almost the same during both seasons. Higher isoprene (2.14 ± 0.66 ppb(v)) and monoterpenes (0.34 ± 0.13 ppb) concentrations in summer than in winter indicate enhanced biogenic emissions. Automotive emissions were the major sources of anthropogenic VOCs, with higher emission ratios of oxygenated and aromatic compounds for heavy-duty and light-duty vehicles, respectively. Daytime oxygenated VOC levels in summer were 2–3 times higher than in winter, indicating greater contributions from the secondary sources. The daytime relative contributions of acetone, acetaldehyde, and isoprene in summer increased by ∼35%–45% compared to winter. The OH-reactivity of isoprene was highest among the measured VOCs, with much higher summer contributions than winter. Oxygenated VOCs contribute significantly to the ozone formation potential in both seasons, while biogenic VOCs only in summer. The box model results at different NO_x-VOC combinations, using observed and simulated VOC data, show that the reductions of VOC levels can effectively reduce the daytime ozone formation rates at higher NO_x concentrations. The study reveals that with the reduction of anthropogenic VOC emissions, biogenic/secondary sources become increasingly important in atmospheric processes in tropical urban regions. Our analysis will be valuable in developing mitigation policies to control primary and secondary pollutants in urban areas in India.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 9","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143932373","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":"Day-Night and Land-Sea Contrasts of Upscale Convective Growths at Coastal South China","authors":"Lin Su,&nbsp;Lanqiang Bai,&nbsp;Sijia Zhang,&nbsp;Guixing Chen,&nbsp;Yu Du","doi":"10.1029/2024JD042643","DOIUrl":"https://doi.org/10.1029/2024JD042643","url":null,"abstract":"<p>Upscale convective growth (UCG) is the key stage for heavy rainfall production within the life cycle of a mesoscale convective system (MCS). The precise prediction of heavy rainfall hinges upon a comprehensive understanding and accurate representation of UCG dynamics. This study investigates the characteristics of pre-summer UCG at coastal South China (CSC), and uncovers noteworthy diurnal and land-sea disparities in UCG at CSC. Convective cells initiated over land tend to grow upscale during the daytime, whereas those triggered over sea surface are more likely to develop at night. Compared with convection initiation, which is closely associated with boundary-layer convergence, UCG relies upon large-scale deep vertical motion in the atmosphere. Environmental dynamic conditions play a dominant role in promoting the UCGs at CSC. The key environmental factors include low-level jet, low-level vortex/shearline, mid-level westerly jet, and vertical wind shear. Nocturnal convective cells triggered over the sea surface demonstrate the greatest likelihoods of upscale growth due to the lower prerequisites for additional environmental conditions for their upscale developments. The MCSs stemming from these convective cells generate the lightest rainfall among all MCSs initiated at CSC. Conversely, daytime convective cells initiated over sea surface and nocturnal convections initiated over land, particularly the former, necessitate exceptionally favorable environmental conditions for their developments, and thus exhibit low probability to grow upscale. The MCSs developed from daytime convective cells initiated over sea surface produce the most intensive rainfall in CSC.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 9","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143932369","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":"Simulation of Tilted Rooftop Photovoltaic Panels at City Scale: Novel Measurements, Model Development, and Application in WRF","authors":"Hang Yin,&nbsp;E. Scott Krayenhoff,&nbsp;James Voogt,&nbsp;Jannik Heusinger,&nbsp;Amir A. Aliabadi","doi":"10.1029/2024JD043133","DOIUrl":"https://doi.org/10.1029/2024JD043133","url":null,"abstract":"<p>Rooftop photovoltaic (PV) panels alter the urban energy balance and affect local climate. However, the use of simplified PV models and models lacking thorough evaluation against observational data has resulted in conflicting conclusions related to their local climate impacts. Here, we further develop a rooftop PV energy balance model, UCRC-Solar, and couple it to the multilayer urban canopy scheme BEP-BEM in the Weather Research and Forecasting (WRF) model. Model extensions include updated radiative and convective energy exchanges between both sides of the PV module and the atmosphere/roof surface. We conduct a year-long measurement campaign in London, Canada, to provide a comprehensive meteorological and energy balance data set for an array of tilted PV panels on a flat roof. The upgraded UCRC-Solar is evaluated extensively against this newly collected PV module surface temperature and electricity production data, both offline and online. Coupled mesoscale WRF simulations for Toronto, Ontario, showcase the impacts on urban climate from different configurations of rooftop PV models. UCRC-Solar with tilted panels shows the most notable daytime warming (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>∼</mo>\u0000 <mn>1.0</mn>\u0000 <mo>°</mo>\u0000 </mrow>\u0000 <annotation> ${sim} 1.0{}^{circ}$</annotation>\u0000 </semantics></math>C) and the least nighttime cooling (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>∼</mo>\u0000 <mn>0.4</mn>\u0000 <mo>°</mo>\u0000 </mrow>\u0000 <annotation> ${sim} 0.4{}^{circ}$</annotation>\u0000 </semantics></math>C) of the near-surface air temperature, followed by UCRC-Solar with flat panels, and finally, the existing WRF PV model, which yields more cooling. Unlike previous work at this scale, our approach includes all relevant physical processes and rigorous model evaluation for extended periods across different locations. Furthermore, the updated UCRC-Solar in WRF permits panels with any tilt, which has not previously been available at this scale.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 9","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD043133","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143932375","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":"KHI Tube & Knot Dynamics in a Weakly Unstable Stratospheric Mixing Event","authors":"Tyler S. Mixa,&nbsp;David C. Fritts,&nbsp;Thomas S. Lund","doi":"10.1029/2024JD041981","DOIUrl":"https://doi.org/10.1029/2024JD041981","url":null,"abstract":"<p>Kelvin-Helmholtz Instabilities (KHI) are known to be significant drivers of atmospheric turbulence. Recent observations show KHI forming with misaligned or angled billow segments that develop connecting vortex tubes and knots (T&amp;K); these features promote distinctive, event-defining instability and mixing characteristics that were not accounted for in prior idealized studies. Though T&amp;K have been shown to increase mixing in KHI events with low Richardson numbers (Ri), their influence in weakly KH-unstable, less-idealized environments is unknown. Here we present modeling results of KHI in the stratosphere to assess the impact of T&amp;K dynamics in weakly KH-unstable environments. Radiosonde wind and temperature profiles from 22 February 2006 near Lamont, Oklahoma, measured vertically offset shear and stability peaks near 16.2 km with a minimum Ri = 0.11. Direct numerical simulations (DNS) of this event reveal decreasing shear and increasing stratification, where Ri increases to 0.2 as the shear and stratification peaks move to a common altitude. The resulting KHI exhibit T&amp;K features forming adjacent to, and in superposition with, secondary convective instabilities (CI) rather than superseding them as in prior T&amp;K studies with Ri = 0.05. Newly discovered “crankshaft” instabilities distort the billows and give rise to secondary KHI with delayed, elevated dissipation. KHI that exhibit T&amp;K dynamics are found to accumulate <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>∼</mo>\u0000 <mn>60</mn>\u0000 </mrow>\u0000 <annotation> ${sim} 60$</annotation>\u0000 </semantics></math>% greater mixing than axially uniform KHI with equal or lower mixing efficiency. The substantial increase in mixing suggests significant contributions of T&amp;K dynamics to KHI events throughout the atmosphere that remain unaddressed in general circulation models' turbulence parameterizations.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 9","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143930418","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":"Recent Lower Stratospheric Ozone Trends in CCMI-2022 Models: Role of Natural Variability and Transport","authors":"Samuel Benito-Barca,&nbsp;Marta Abalos,&nbsp;Natalia Calvo,&nbsp;Hella Garny,&nbsp;Thomas Birner,&nbsp;Nathan Luke Abraham,&nbsp;Hideharu Akiyoshi,&nbsp;Fraser Dennison,&nbsp;Patrick Jöckel,&nbsp;Bèatrice Josse,&nbsp;James Keeble,&nbsp;Doug Kinnison,&nbsp;Marion Marchand,&nbsp;Olaf Morgenstern,&nbsp;David Plummer,&nbsp;Eugene Rozanov,&nbsp;Sarah Strode,&nbsp;Timofei Sukhodolov,&nbsp;Shingo Watanabe,&nbsp;Yousuke Yamashita","doi":"10.1029/2024JD042412","DOIUrl":"https://doi.org/10.1029/2024JD042412","url":null,"abstract":"<p>Lower stratospheric ozone between 60°S and 60°N has continued to decline since 1998, despite the reduction of ozone-depleting substances following the Montreal Protocol. Previous studies have shown that, while chemistry-climate models reproduce the negative ozone trend in the tropical lower stratosphere as a response to increased upwelling, they fail to capture the ozone decline in northern midlatitudes. This study revisits recent lower stratospheric ozone trends over the period 1998–2018 using two types of simulations from the new Chemistry Climate Model Initiative 2022 (CCMI-2022): REF-D1, with observed sea surface temperatures, and REF-D2, with simulated ocean. The observed negative trend in midlatitudes falls within the range of model trends, especially when considering simulations with observed boundary conditions. There is a large spread in the simulated midlatitudes ozone trends, with some simulations showing positive and others negative trends. A multiple linear regression analysis shows that the spread in the trends is not explained by the different linear response to external forcings (solar cycle, global warming, and ozone-depleting substances) or to the main variability modes (El Niño-Southern Oscillation and the quasi-biennial oscillation) but is instead attributed to internal atmospheric variability. Moreover, the fact that some models show very different trends across members, while other models show similar trends in all members, suggests fundamental differences in the representation of the internal variability of ozone transport across models. Indeed, we report substantial intermodel differences in the ozone-transport connection on interannual timescales and we find that ozone trends are closely coupled to transport trends.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 9","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD042412","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143930231","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":"Improving Tropical Cyclone Track Forecast Skill Through Assimilating Target Observation Achieved by AI-Based Conditional Nonlinear Optimal Perturbation","authors":"Yonghui Li,&nbsp;Wansuo Duan,&nbsp;Wei Han,&nbsp;Hao Li,&nbsp;Xiaohao Qin","doi":"10.1029/2024JD043261","DOIUrl":"https://doi.org/10.1029/2024JD043261","url":null,"abstract":"<p>The artificial intelligence (AI)-based weather forecasting model named FuXi and its data assimilation (DA) system FuXi-En4DVar has been developed for high-efficiently forecasting high-impact weather events such as tropical cyclones (TCs). Besides conventional observations, target observations are essential to further improve initial field accuracy and then increasing high-impact weather event forecasting skills. The identification of the sensitive area, where the additional observations should be deployed, is the key to implementing target observations. In this paper, a sensitive area identification system is established for the FuXi model on the basis of FuXi-En4DVar, based on the fully nonlinear method of conditional nonlinear optimal perturbation (CNOP). The CNOP represents the optimally growing initial perturbation and can be calculated by using the adjoint of numerical models in numerical forecast models, but in the AI-based FuXi model, it is solved by directly using the automatic differential algorithm embedded in the FuXi model. Such an approach of calculating CNOP significantly increases the computational efficiency. Applying this system to the forecasts of 11 TCs demonstrates that the additional target observations can significantly improve TC track forecast skills, as compared with the other additional observations. Moreover, a small number of additional target observations can be expected to achieve the forecast skill comparable to, or even surpassing to, that obtained by tens of times more observations. This validation shows the potential of applying dynamical CNOP to AI-based model for highly effectively identifying the sensitive area for target observations associated with TC forecasting.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 9","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143930232","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":"Simulations of Convectively Coupled Kelvin Waves (CCKWs) With Three Different Cumulus Parameterization Schemes","authors":"Se-Hyun Lee,&nbsp;Sang-Hun Park,&nbsp;Mu-Ting Chien,&nbsp;Daehyun Kim","doi":"10.1029/2024JD042738","DOIUrl":"https://doi.org/10.1029/2024JD042738","url":null,"abstract":"<p>Convectively coupled Kelvin waves (CCKWs) significantly influence tropical rainfall variability; however, accurately simulating these waves remains a challenge in atmospheric modeling. Cumulus parameterization is a critical element in model-generated CCKW activity among the various factors. This study investigated the impact of cumulus parameterization on CCKW simulation by analyzing the coupling mechanism between tropical convection and Kelvin waves, expanding on the stratiform instability theory. This theory suggests that CCKWs are enhanced through a positive feedback loop between stratiform heating and temperature. We aimed to minimize contamination from large-scale environmental influences by employing the Weather Research and Forecasting (WRF) model configured for tropical channel simulations with spectral nudging. We assessed three distinct cumulus parameterization schemes: Grell-Freitas (GF), Multi-scale Kain-Fritsch (MSKF), and New Tiedtke (NTDK). Our analysis revealed that the NTDK scheme simulates the strongest CCKW signal, whereas the GF and MSKF schemes exhibit weaker signals. The vertical-mode decomposition of diabatic heating and temperature identified two prominent modes corresponding to deep convection and stratiform precipitation. The results demonstrated that NTDK shows the most favorable conditions for CCKW enhancement, characterized by substantial contributions from the second mode of heating and temperature anomalies. These aspects underline the critical role of cumulus parameterization for the enhancement of CCKWs, highlighting the importance of accurately representing stratiform instability to reduce deficiencies in CCKW modeling.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 9","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD042738","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143930233","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":"Resolving Mesoscale Convective Systems: Grid Spacing Sensitivity in the Tropics and Midlatitudes","authors":"Andreas F. Prein,&nbsp;Dié Wang,&nbsp;Ming Ge,&nbsp;Alexandra Ramos Valle,&nbsp;Manda B. Chasteen","doi":"10.1029/2024JD042530","DOIUrl":"https://doi.org/10.1029/2024JD042530","url":null,"abstract":"&lt;p&gt;Mesoscale convective systems (MCSs) are a critical global water cycle component and drive extreme precipitation events in tropical and midlatitude regions. However, simulating deep convection remains challenging for modern numerical weather and climate models due to the complex interactions of processes from microscales to synoptic scales. Recent models with kilometer-scale horizontal grid spacings &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;mi&gt;Δ&lt;/mi&gt;\u0000 &lt;mi&gt;x&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $({Delta }x)$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; offer notable improvements in simulating deep convection compared to coarser-resolution models. Still, deficiencies in representing key physical processes, such as entrainment, lead to systematic biases. Additionally, evaluating model outputs using process-oriented observational data remain difficult. This study presents an ensemble of MCS simulations with &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;Δ&lt;/mi&gt;\u0000 &lt;mi&gt;x&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${Delta }x$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; spanning the deep convective gray zone (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;Δ&lt;/mi&gt;\u0000 &lt;mi&gt;x&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${Delta }x$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; from 12 km to 125 m) in the Southern Great Plains of the U.S. and the Amazon Basin. Comparing these simulations with Atmospheric Radiation Measurement (ARM) wind profiler observations, we find greater &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;Δ&lt;/mi&gt;\u0000 &lt;mi&gt;x&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${Delta }x$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; sensitivity in the Amazon Basin compared to the Great Plains. Convective drafts converge structurally at sub-kilometer scales, but some deficiencies remain. In both regions, simulated up and downdrafts are too deep and extreme downdrafts are not strong enough. Furthermore, Amazonian updrafts are too strong. Overall, we observe higher &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;Δ&lt;/mi&gt;\u0000 &lt;mi&gt;x&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${Delta }x$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; sensitivity in the tropics, including an artificial buildup in vertical kinetic energy at scales of &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;mi&gt;Δ&lt;/mi&gt;\u0000 &lt;mi&gt;x&lt;/m","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 9","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD042530","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143919864","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 Influences of Mesoscale SSTA on North Pacific Storm Tracks During Different PDO Phases","authors":"Chao Zhang,&nbsp;Hailong Liu,&nbsp;Peilong Yu,&nbsp;Minghao Yang,&nbsp;Yunying Li","doi":"10.1029/2024JD043292","DOIUrl":"https://doi.org/10.1029/2024JD043292","url":null,"abstract":"<p>Previous studies have demonstrated that extratropical large-scale and mesoscale sea surface temperature anomalies (SSTA) could impact the storm tracks. However, their combined influence on storm tracks remains to be determined. To answer this question, we defined four phases to represent the different combinations of large-scale SSTA patterns in the North Pacific and mesoscale SSTA in Kuroshio and Oyashio confluence region (KOCR), based on the standardized mesoscale SSTA index and the Pacific decadal oscillation (PDO) index. The storm tracks' response mainly exhibits a significant meridional dipolar structure in all phases, primarily driven by the mesoscale SSTA and consistent with previous studies. However, the details of the reaction differ under the modulation of PDO. Our findings also suggest the role of PDO is more pronounced when the variation of mesoscale SSTA is strong. Additionally, the storm tracks show more elongated and asymmetric anomalies in the warm PDO phase than the cold PDO phase. The key mechanism behind this is as follows. It revealed that the baroclinic processes associated with mesoscale SSTA are important in shaping storm tracks. The variation of mesoscale SSTA in KOCR changes the upward transportation of moisture and heat, which may alter diabatic heating. Consequently, differences emerge in the meridional gradient of air temperature, modifying the baroclinicity of the troposphere. Through baroclinic energy conversion, the influence finally impacts the storm tracks. PDO totally modulates these processes. In conclusion, the development of the North Pacific storm tracks are influenced by the combined effects of large-scale and mesoscale SSTA.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 9","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143919865","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}