Journal of the Atmospheric Sciences最新文献_第4页

Non-local Controls on Tropical Cyclogenesis: A Trajectory-based Genesis Potential Index 热带气旋形成的非局地控制:基于轨迹的形成势指数

3区地球科学

Journal of the Atmospheric Sciences Pub Date : 2023-10-31 DOI: 10.1175/jas-d-23-0025.1

Lingwei Meng, Stephen T. Garner

{"title":"Non-local Controls on Tropical Cyclogenesis: A Trajectory-based Genesis Potential Index","authors":"Lingwei Meng, Stephen T. Garner","doi":"10.1175/jas-d-23-0025.1","DOIUrl":"https://doi.org/10.1175/jas-d-23-0025.1","url":null,"abstract":"Abstract Tropical cyclone (TC) genesis is initiated by convective precursors or “seeds” and influenced by environmental conditions along the seed-to-TC trajectories. Genesis Potential Indices (GPIs) provide a simple way to evaluate TC genesis likelihood from environmental conditions, but have two limitations that may introduce bias. First, the globally fixed GPIs fail to represent inter-basin differences in the relationship between environments and genesis. Second, existing GPIs are only functions of local environmental conditions, whereas non-local factors may have a significant impact. We address the first limitation by constructing basin- and timescale-specific GPIs ( local-GPI s) over the Eastern North Pacific (ENP) and North Atlantic (NA) using Poisson regression. A sequential feature selection algorithm (SFS) identifies vertical wind shear and a heating condition as leading factors controlling TC genesis in the ENP and the NA, respectively. However, only a slight improvement in performance is achieved, motivating us to tackle the second limitation with a novel trajectory-based GPI ( traj-GPI ). We merge adjacent non-local environments into each grid point based on observed seed trajectory densities. The seed activity, driven mainly by upward motion, and the transition to TCs, controlled primarily by vertical wind shear or heating conditions, are captured simultaneously in the traj-GPI , yielding a better performance than the original GPIs. This study illustrates the importance of seed activity in modeling TC genesis and identifies key environmental factors that influence the process of TC genesis at different stages.","PeriodicalId":17231,"journal":{"name":"Journal of the Atmospheric Sciences","volume":"14 10","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135863781","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

On the impact of a dry intrusion driving cloud-regime transitions in a midlatitude cold-air outbreak 在中纬度冷空气爆发中，干旱入侵驱动云态转变的影响

3区地球科学

Journal of the Atmospheric Sciences Pub Date : 2023-10-27 DOI: 10.1175/jas-d-23-0040.1

Florian Tornow, Andrew S. Ackerman, Ann M. Fridlind, George Tselioudis, Brian Cairns, David Painemal, Gregory Elsaesser

{"title":"On the impact of a dry intrusion driving cloud-regime transitions in a midlatitude cold-air outbreak","authors":"Florian Tornow, Andrew S. Ackerman, Ann M. Fridlind, George Tselioudis, Brian Cairns, David Painemal, Gregory Elsaesser","doi":"10.1175/jas-d-23-0040.1","DOIUrl":"https://doi.org/10.1175/jas-d-23-0040.1","url":null,"abstract":"Abstract Marine cold-air outbreaks (CAOs) occur in the post-frontal sector of midlatitude storms, usually accompanied by dry intrusions (DIs) shaping the free-tropospheric (FT) air aloft. Substantial rain initiates overcast-to-broken regime transitions in marine boundary layer (MBL) cloud decks that form where cold air first meets relatively high sea-surface temperatures. An exemplary CAO in the northwest Atlantic shows earlier transitions (corresponding to reduced extents of overcast clouds) closer to the low-pressure center. We hypothesize that gradients in the meteorological pattern imposed by the prevailing DI induced a variability in substantial rain onset and thereby transition. We compile satellite observations, reanalysis fields, and Lagrangian large-eddy simulations (LES) translating along MBL trajectories to show that postfrontal trajectories closer to the low-pressure center are more favorable to rain formation (and thereby cloud transitions) because of (1) weaker FT subsidence rates, (2) greater FT humidity, (3) stronger MBL winds, and (4) a colder MBL with reduced lower-tropospheric stability. LES confirms the observed variability in transitions, with substantial rain appearing earlier where there is swifter reduction of cloud condensation nucleus (CCN) concentration and increase of liquid water path (LWP). Prior to substantial rain, CCN budgets indicate dominant loss terms from FT entrainment and hydrometeor collisions. LWP-enhancing cloud thickness increases more rapidly for weaker large-scale subsidence that enables faster MBL deepening. Mere MBL warming and moistening cannot explain cloud thickness increases. The generality of such a DI-imposed cloud transition pattern merits further investigation with more cases that may additionally be convoluted by onshore aerosol gradients.","PeriodicalId":17231,"journal":{"name":"Journal of the Atmospheric Sciences","volume":"4 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136318288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Review of the Interactions between Tropical Cyclones and Environmental Vertical Wind Shear 热带气旋与环境垂直风切变相互作用的研究进展

3区地球科学

Journal of the Atmospheric Sciences Pub Date : 2023-10-27 DOI: 10.1175/jas-d-23-0022.1

Rosimar Rios-Berrios, Peter M. Finocchio, Joshua J. Alland, Xiaomin Chen, Michael S. Fischer, Stephanie N. Stevenson, Dandan Tao

{"title":"A Review of the Interactions between Tropical Cyclones and Environmental Vertical Wind Shear","authors":"Rosimar Rios-Berrios, Peter M. Finocchio, Joshua J. Alland, Xiaomin Chen, Michael S. Fischer, Stephanie N. Stevenson, Dandan Tao","doi":"10.1175/jas-d-23-0022.1","DOIUrl":"https://doi.org/10.1175/jas-d-23-0022.1","url":null,"abstract":"Abstract Tropical cyclone (TC) structure and intensity are strongly modulated by interactions with deep-layer vertical wind shear (VWS)—the vector difference between horizontal winds at 200 and 850 hPa. This paper presents a comprehensive review of more than a century of research on TC-VWS interactions. The literature broadly agrees that a TC vortex becomes vertically tilted, precipitation organizes into a wavenumber-one asymmetric pattern, and thermal and kinematic asymmetries emerge when a TC encounters an environmental sheared flow. However, these responses depend on other factors, including the magnitude and direction of horizontal winds at other vertical levels between 200 and 850 hPa, the amount and location of dry environmental air, and the underlying sea-surface temperature. While early studies investigated how VWS weakens TCs, an emerging line of research has focused on understanding how TCs intensify under moderate and strong VWS (i.e., shear magnitudes greater than 5 m s −1 ). Modeling and observational studies have identified four pathways to intensification: vortex tilt reduction, vortex reformation, axisymmetrization of precipitation, and outflow blocking. These pathways may not be uniquely different because convection and vortex asymmetries are strongly coupled to each other. Besides discussing these topics, this review presents open questions and recommendations for future research on TC-VWS interactions.","PeriodicalId":17231,"journal":{"name":"Journal of the Atmospheric Sciences","volume":"87 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136317707","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Variable Rainfall over Steady SST: The Effect of the Free Troposphere on Surface Pressure in the East Pacific 稳定海温上的变雨量:自由对流层对东太平洋地面压力的影响

3区地球科学

Journal of the Atmospheric Sciences Pub Date : 2023-10-23 DOI: 10.1175/jas-d-23-0101.1

Isabelle Bunge, Adam Sobel, Michela Biasutti, Shuguang Wang

{"title":"Variable Rainfall over Steady SST: The Effect of the Free Troposphere on Surface Pressure in the East Pacific","authors":"Isabelle Bunge, Adam Sobel, Michela Biasutti, Shuguang Wang","doi":"10.1175/jas-d-23-0101.1","DOIUrl":"https://doi.org/10.1175/jas-d-23-0101.1","url":null,"abstract":"Abstract Surface winds and precipitation over the tropical oceans are related to sea surface temperature (SST) through multiple mechanisms. Greater SST is associated with greater conditional instability, which in turn is more conducive to deep convection. The associated mass and flow responses can extend to the surface, via associated pressure gradients imprinted on the top of the planetary boundary layer (PBL). SST also influences surface pressure and wind directly through its control over PBL temperature, as explained by Lindzen and Nigam (1987). The authors examine the relative magnitudes of these two influences over the eastern tropical Pacific on subseasonal precipitation variability during northern summer, when and where SST gradients are largest and the direct influence via PBL temperature is expected to be strongest. Geopotential at 1000 hPa is partitioned into two components: the geopotential at PBL top (PBL top is chosen to be 850 hPa, supported by an analysis of the vertical structure of geopotential and temperature), and the PBL thickness. These fields are composited on quintiles of daily ITCZ precipitation both with and without a high-pass filter that isolates subseasonal timescales. The PBL thickness varies little between the highest and lowest precipitation quintiles, while the PBL top geopotential varies much more. This supports a view in which the direct contribution of SST to the surface pressure and flow fields, including the associated PBL convergence over sharp SST maxima, can be viewed as a steady forcing on the rest of the column, while free-tropospheric transients contribute most of the variability associated with precipitation on subseasonal timescales.","PeriodicalId":17231,"journal":{"name":"Journal of the Atmospheric Sciences","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135366464","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Interactions between gravity waves and cirrus clouds: asymptotic modeling of wave induced ice nucleation 重力波与卷云之间的相互作用:波诱导冰成核的渐近模拟

3区地球科学

Journal of the Atmospheric Sciences Pub Date : 2023-10-19 DOI: 10.1175/jas-d-22-0234.1

Stamen I. Dolaptchiev, Peter Spichtinger, Manuel Baumgartner, Ulrich Achatz

{"title":"Interactions between gravity waves and cirrus clouds: asymptotic modeling of wave induced ice nucleation","authors":"Stamen I. Dolaptchiev, Peter Spichtinger, Manuel Baumgartner, Ulrich Achatz","doi":"10.1175/jas-d-22-0234.1","DOIUrl":"https://doi.org/10.1175/jas-d-22-0234.1","url":null,"abstract":"Abstract We present an asymptotic approach for the systematic investigation of the effect of gravity waves (GW) on ice clouds formed through homogeneous nucleation. In particular, we consider high- and mid-frequency GW in the tropopause region driving the formation of ice clouds, modeled with a double-moment bulk ice microphysics scheme. The asymptotic approach allows for identifying reduced equations for self-consistent description of the ice dynamics forced by GW including the effects of diffusional growth and nucleation of ice crystals. Further, corresponding analytical solutions for a monochromatic GW are derived under a single-parcel approximation. The results provide a simple expression for the nucleated number of ice crystals in a nucleation event. It is demonstrated that the asymptotic solutions capture the dynamics of the full ice model and accurately predict the nucleated ice crystal number. The present approach is extended to allow for superposition of GW, as well as, for variable ice crystal mean mass in the deposition. Implications of the results for an improved representation of GW variability in cirrus parameterizations are discussed.","PeriodicalId":17231,"journal":{"name":"Journal of the Atmospheric Sciences","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135730186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Simulating the transition from shallow to deep convection across scales: the role of congestus clouds 模拟跨尺度从浅对流到深对流的转变:拥塞云的作用

3区地球科学

Journal of the Atmospheric Sciences Pub Date : 2023-10-18 DOI: 10.1175/jas-d-23-0027.1

Aude Champouillon, Catherine Rio, Fleur Couvreux

{"title":"Simulating the transition from shallow to deep convection across scales: the role of congestus clouds","authors":"Aude Champouillon, Catherine Rio, Fleur Couvreux","doi":"10.1175/jas-d-23-0027.1","DOIUrl":"https://doi.org/10.1175/jas-d-23-0027.1","url":null,"abstract":"Abstract An idealized case of gradual oceanic transition from shallow to deep convection based on Kuang and Bretherton (2006) is simulated at three different horizontal resolutions: one that resolves most of the turbulent eddies, one typical of cloud-resolving models and one typical of general circulation models. The former serves as a reference, and allows the identification of clouds as individual objects, distinguishing shallow cumulus, congestus and cumulonimbus. At coarser resolutions, parameterizations of convection are included and assessed, with a particular focus on congestus clouds and precipitation associated with shallow convective clouds. Congestus clouds are found to contribute the most to turbulent transport during the transition, while occupying a volume comparable to shallow cumulus and cumulonimbus. Kilometer-scale horizontal resolutions prove to be insufficient to resolve congestus, and parameterization schemes of shallow and deep convection are not necessarily appropriate to represent those intermediate clouds. The representation of rainfall in the shallow convection scheme plays a key role in the transition. Sensitivity experiments show that enhanced rainfall inhibits convection in single-column simulations, while it favors resolved convection and spatial heterogeneities in three-dimensional simulations with kilometer-scale resolution. Results highlight the need for an appropriate parameterization of congestus in both kilometer-scale and large-scale models. The case study and the methods presented here are proposed as a useful framework to evaluate models and their parameterizations in a shallow-to-deep convection transition context.","PeriodicalId":17231,"journal":{"name":"Journal of the Atmospheric Sciences","volume":"33 5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135888186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Barotropic and Moisture-vortex growth of Monsoon Low Pressure Systems 季风低压系统的正压和水涡增长

3区地球科学

Journal of the Atmospheric Sciences Pub Date : 2023-10-16 DOI: 10.1175/jas-d-22-0252.1

Haochang Luo, Ángel F. Adames Corraliza, Richard B. Rood

{"title":"Barotropic and Moisture-vortex growth of Monsoon Low Pressure Systems","authors":"Haochang Luo, Ángel F. Adames Corraliza, Richard B. Rood","doi":"10.1175/jas-d-22-0252.1","DOIUrl":"https://doi.org/10.1175/jas-d-22-0252.1","url":null,"abstract":"Abstract As one of the most prominent weather systems over the Indian subcontinent, the Indian summer monsoon low pressure systems (MLPSs) have been studied extensively over the past decades. However, the processes that govern the growth of the MLPSs are not well understood. To better understand these processes, we created an MLPS index using bandpass-filtered precipitation data. Lag regression maps and vertical cross-sections are used to document the distribution of moisture, moist static energy (MSE), geopotential, horizontal and vertical motions in these systems. It is shown that moisture governs the distribution of MSE and is in phase with precipitation, vertical motion, and geopotential during the MLPS cycle. Examination of the MSE budget reveals that longwave radiative heating maintains the MSE anomalies against dissipation from vertical MSE advection. These processes nearly cancel one another, and it is variations in horizontal MSE advection that are found to explain the growth and decay of the MSE anomalies. Horizontal MSE advection contributes to the growth of the MSE anomalies in MLPSs prior to the system attaining a maximum amplitude and contributes to decay thereafter. The horizontal MSE advection is largely due to meridional advection of mean state MSE by the anomalous winds, suggesting that the MSE anomalies undergo a moisture-vortex instability (MVI)-like growth. In contrast, perturbation kinetic energy (PKE) is generated through barotropic conversion. The structure, propagation, and energetics of the regressed MLPSs are consistent with both barotropic and moisture-vortex growth.","PeriodicalId":17231,"journal":{"name":"Journal of the Atmospheric Sciences","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136112891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Ubiquitous Sea Surface Temperature Anomalies Increase Spatial Heterogeneity of Trade-Wind Cloudiness on Daily Timescale 普遍存在的海温异常增加了信风云量在日尺度上的空间异质性

3区地球科学

Journal of the Atmospheric Sciences Pub Date : 2023-10-16 DOI: 10.1175/jas-d-23-0075.1

Xuanyu Chen, Juliana Dias, Brandon Wolding, Robert Pincus, Charlotte DeMott, Gary Wick, Elizabeth J. Thompson, Chris W. Fairall

{"title":"Ubiquitous Sea Surface Temperature Anomalies Increase Spatial Heterogeneity of Trade-Wind Cloudiness on Daily Timescale","authors":"Xuanyu Chen, Juliana Dias, Brandon Wolding, Robert Pincus, Charlotte DeMott, Gary Wick, Elizabeth J. Thompson, Chris W. Fairall","doi":"10.1175/jas-d-23-0075.1","DOIUrl":"https://doi.org/10.1175/jas-d-23-0075.1","url":null,"abstract":"Abstract The impact of weak submeso- to meso-scale SST anomalies on daily averaged trade cumulus cloudiness is investigated using satellite observations that have been validated against ship-board measurements from the Atlantic Tradewind Ocean-Atmosphere Mesoscale Interaction Campaign (ATOMIC). Daily spatial SST anomalies are identified from GOES-POES blended SST analysis within a 10° by 10° region during January and February 2020. Daily-averaged cloud fraction and 10-m neutral wind from satellite observations and reanalysis are composited over the identified SST features, using a common coordinate system based on the near surface background wind directions. Composites of satellite cloud fraction show a statistically significant increase of cloudiness over the SST warm core with a reduction of cloudiness away from it. These responses are largely the same but with opposite signs over SST cold anomalies, suggesting that spatial heterogeneity in SST can locally imprint on daily cloud fraction. Composites of daily 10-m wind speed and wind convergence anomalies from both satellite and reanalysis show that surface wind speed is increased over SST warm anomalies, implying enhanced turbulence over warmer SSTs. Correspondingly, the surface convergence anomalies in these composites are located around the maximum downwind SST gradient, offset downwind from the cloudiness anomalies. These results indicate that the response of daily cloudiness to these SST anomalies is more likely generated by spatial variability of surface-driven turbulence and surface fluxes rather than that of surface or boundary layer convergence.","PeriodicalId":17231,"journal":{"name":"Journal of the Atmospheric Sciences","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136114004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Statistical characteristics of mesoscale fluctuations of wind velocity, temperature, and gas concentrations obtained from aircraft measurements in the troposphere of the Arctic region 北极地区对流层中风速、温度和气体浓度中尺度波动的统计特征

3区地球科学

Journal of the Atmospheric Sciences Pub Date : 2023-10-13 DOI: 10.1175/jas-d-23-0021.1

I. Chunchuzov, O. Chkhetiani, S. Kulichkov, O. Popov, B Belan, A. Fofonov, G Ivlev, A. Kozlov

{"title":"Statistical characteristics of mesoscale fluctuations of wind velocity, temperature, and gas concentrations obtained from aircraft measurements in the troposphere of the Arctic region","authors":"I. Chunchuzov, O. Chkhetiani, S. Kulichkov, O. Popov, B Belan, A. Fofonov, G Ivlev, A. Kozlov","doi":"10.1175/jas-d-23-0021.1","DOIUrl":"https://doi.org/10.1175/jas-d-23-0021.1","url":null,"abstract":"Abstract The results of airborne measurements and statistical characteristics of mesoscale fluctuations of wind velocity, temperature and concentrations of gas constituents at different heights of stably stratified troposphere are presented. The measurements were carried out in September 2022 in the Arctic region of Russia with the aircraft-laboratory Tu-134 \"Optik\". The obtained spectra and structure functions of the fluctuations are interpreted with the theoretical model of formation of the spectrum of mesoscale wind velocity and temperature fluctuations described in the paper. The presence at high wave numbers of a steep section in the obtained horizontal wave number spectra of the fluctuations of wind velocity and greenhouse gas concentration with a slope close to −3 is discussed. The fluctuation spectra along different slanted tracks of the aircraft crossing the tropospheric layer between altitudes of 1 and 9 km are also obtained and analyzed with the theoretical model.","PeriodicalId":17231,"journal":{"name":"Journal of the Atmospheric Sciences","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135918374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Kinematic Modeling Study of the Re-Organization of Snowfall between Cloud-top Generating Cells and low-level Snow Bands in Midlatitude Winter Storms 中纬度冬季风暴中云顶生成单体与低层雪带之间降雪重新组织的运动学模拟研究

3区地球科学

Journal of the Atmospheric Sciences Pub Date : 2023-09-28 DOI: 10.1175/jas-d-23-0024.1

Andrew Janiszeski, Robert M. Rauber, Brian F. Jewett, Greg M. McFarquhar, Troy J. Zaremba, John E. Yorks

{"title":"A Kinematic Modeling Study of the Re-Organization of Snowfall between Cloud-top Generating Cells and low-level Snow Bands in Midlatitude Winter Storms","authors":"Andrew Janiszeski, Robert M. Rauber, Brian F. Jewett, Greg M. McFarquhar, Troy J. Zaremba, John E. Yorks","doi":"10.1175/jas-d-23-0024.1","DOIUrl":"https://doi.org/10.1175/jas-d-23-0024.1","url":null,"abstract":"Abstract This paper explores whether particles within uniformly-spaced generating cells falling at terminal velocity within observed 2-D wind fields and idealized deformation flow beneath cloud top can be reorganized consistent with the presence of single and multi-banded structures present on WSR-88D radars. In the first experiment, two-dimensional wind fields, calculated along cross-sections normal to the long-axis of snow bands observed during three Northeast U.S. winter storms, were taken from the initialization of the High Resolution Rapid Refresh model. This experiment demonstrated that the greater the residence time of the particles in each of the three storms, the greater particle reorganization occurred. For experiments with longer residence times, increases in particle concentrations were nearly or directly collocated with reflectivity bands. For experiments with shorter residence times, particle reorganization still conformed to the band features but with less concentration enhancement. This experiment demonstrates that the combination of long particle residence time and net convergent cross-sectional flow through the cloud depth is sufficient to re-organize particles into locations consistent with precipitation bands. Increased concentrations of ice particles can then contribute, along with any dynamic forcing, to the low-level reflectivity bands seen on WSR-88D radars. In a second experiment, the impact of flow deformation on the re-organization of falling ice particles was investigated using an idealized kinematic model with stretching deformation flow of different depths and magnitudes. These experiments showed that deformation flow provides for little particle reorganization given typical deformation layer depths and magnitudes within the comma head of such storms.","PeriodicalId":17231,"journal":{"name":"Journal of the Atmospheric Sciences","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135387254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0