Journal of Geophysical Research: Atmospheres最新文献

{"title":"Application of an Artificial Neural Network to Improve Understanding of the Observed Conterminous US Winter Precipitation Response to ENSO","authors":"Chibuike Chiedozie Ibebuchi,&nbsp;Michael B. Richman,&nbsp;Omon A. Obarein,&nbsp;Seth Rainey,&nbsp;Alindomar Silva","doi":"10.1029/2024JD041735","DOIUrl":"https://doi.org/10.1029/2024JD041735","url":null,"abstract":"<p>El Niño Southern Oscillation (ENSO) is known to modulate rainfall variability in parts of the conterminous United States (US). Owing to the complexity of the climate system, the variability in US winter (DJF) precipitation response to ENSO is investigated. By regressing autoencoder neural network-based ENSO types (i.e., encoded tropical Pacific Sea surface temperature anomaly patterns) onto DJF US precipitation, supplemented with support vector regression and extreme gradient-boosting regression, we show that ENSO modulation of precipitation is regionally sensitive to the ENSO type. Certain regions exhibit significant nonlinear relationships between precipitation and strong ENSO event phase that was most pronounced over the eastern and northwestern quadrants of the US. The coherency of the response varies among individual events. Specifically, among individual events, differences in ENSO SST anomaly patterns were linked to meridional shifts in the positioning of the Pacific jet stream. This leads to variable anomalous upper-level flow and atmospheric conditions influencing US winter precipitation during the ENSO events. By analyzing associations between DJF precipitation and ENSO types whilst assessing the consistency of precipitation anomalies during strong ENSO events, we identify the regional likelihood of consistent precipitation responses, thereby calibrating confidence in seasonal ENSO-precipitation responses.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 7","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD041735","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143726760","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":"Centennial-Scale Variability in Atmospheric Circulation in Antarctica: Insights From a Coastal East Antarctic Ice Core Record","authors":"Zhe Li,&nbsp;Guitao Shi,&nbsp;Su Jiang,&nbsp;Danhe Wang,&nbsp;Bo Zhang,&nbsp;Tianming Ma,&nbsp;Jinhai Yu,&nbsp;Jingxue Guo","doi":"10.1029/2024JD042991","DOIUrl":"https://doi.org/10.1029/2024JD042991","url":null,"abstract":"<p>A 108-m ice core (32SC) spanning the period from 1616 to 2016 CE was retrieved from coastal Princess Elizabeth Land (PEL), East Antarctica (69.97°S, 76.52°E, 1,113 m elevation). The ice core was analyzed to investigate the relationship between sea salt aerosols (SSAs), sea ice dynamics, and atmospheric circulation. The first component of Empirical Orthogonal Function analysis (32SC REOF1), which explains 58% of the variance in the ice core ions, serves as a proxy for SSAs. Time series correlation analysis reveals that sea ice had a minimal impact on 32SC REOF1. Instead, it showed a significant correlation with winter meridional atmospheric transport from the Southern Indian Ocean to PEL. The sea salt records exhibit a significant increase from the period 1616–1850 to 1851–2016 CE, with the mean value increasing by a factor of 2.4. This centennial-scale trend is likely linked to shifts in the position of the Southern Hemisphere Westerly Winds (SHWW). During the earlier period (1616–1850 CE), which was likely characterized by a colder climate, the SHWW in the Southern Indian Ocean sector may have shifted equatorward and weakened in intensity, potentially leading to reduced cyclone frequency and a subsequent decline in SSAs transport to high latitudes. In contrast, the period 1851–2016 CE, which is likely warmer, saw the SHWW shifted poleward, enhancing meridional wind speeds and increasing SSAs transport. Comparisons with other Antarctic ice core records suggest that the centennial-scale shift in the SHWW is a regional phenomenon, particularly pronounced in the Southern Indian Ocean.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 7","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143717072","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":"Assessing Cloud Fraction in the Canadian Regional Climate Model Over North America Using Satellite Data and a Satellite Simulator Package","authors":"K. Veilleux,&nbsp;A. Di Luca,&nbsp;J. M. Thériault,&nbsp;V. Poitras,&nbsp;P. A. Vaillancourt,&nbsp;M. Cholette,&nbsp;F. Roberge","doi":"10.1029/2024JD042453","DOIUrl":"https://doi.org/10.1029/2024JD042453","url":null,"abstract":"<p>Clouds are crucial to Earth's climate system, influencing radiation and contributing to climate projection uncertainties. Here, the simulated cloud fraction by the sixth version of the Canadian Regional Climate Model (CRCM6-GEM5) was evaluated using CALIPSO lidar retrievals and the second version of the Cloud Feedback Intercomparison Project (CFMIP) Observation Simulator Package (COSP2) for the years 2014 and 2015. Horizontal and vertical distributions of clouds in the CRCM6-GEM5 model were evaluated using cloud profiles and four cloud categories (total, high-, mid-, and low-level clouds) derived directly from the CRCM6-GEM5 model and treated using the COSP2 satellite simulator. A seasonal analysis was conducted across specific regions in North America. Results showed that the use of COSP2 is essential for comparing CRCM6-GEM5 outputs against satellite data to account for variable definitions and signal attenuation of active instruments (e.g., Cloud-Aerosol Lidar with Orthogonal Polarization: CALIOP). Spatial and vertical cloud distributions and seasonal patterns were generally well represented by the CRCM6-GEM5 for both winter (December–February) and summer (June–August). High- and low-level clouds were particularly well-represented, especially in winter. The CRCM6-GEM5 model demonstrated some difficulty producing enough clouds to accurately represent those at mid-level. Cloud fraction representation was systematically better during winter than summer. The CRCM6-GEM5 generally performed well over the whole North American domain for the four cloud categories and COSP2 was confirmed to help mitigate discrepancies in variable definitions. These results contribute to a better understanding of the CRCM6-GEM5 cloud representations and the use of COSP2 with high-resolution models.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 7","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD042453","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143717071","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":"Observing Lower-Tropospheric Ozone Spatiotemporal Variability With Airborne Lidar and Surface Monitors in Houston, Texas","authors":"Mary Angelique G. Demetillo,&nbsp;Laura M. Judd,&nbsp;Katherine R. Travis,&nbsp;James H. Crawford,&nbsp;Prajjwal Rawat,&nbsp;Johnathan W. Hair,&nbsp;Marta Fenn,&nbsp;Richard Ferrare,&nbsp;Taylor Shingler,&nbsp;John T. Sullivan,&nbsp;Paul Walter,&nbsp;James Flynn,&nbsp;Travis Griggs","doi":"10.1029/2024JD042916","DOIUrl":"https://doi.org/10.1029/2024JD042916","url":null,"abstract":"<p>Surface-level ozone is a trace gas regulated by the Environmental Protection Agency as its oxidizing properties are detrimental to air quality, impacting human and environmental health. Satellite observations provide spatially continuous intraurban ozone distributions, potentially filling in gaps within monitoring networks. However, near-surface ozone is difficult to retrieve from columns due to the large signal in the stratosphere and lack of sensitivity to the lower troposphere in the ultraviolet wavelengths. Airborne lidar measurements of ozone profiles present the opportunity to assess vertical, geospatial, and temporal variability of lower tropospheric (0–2 km) near-surface ozone subcolumn products for air quality analyses. This study uses the first city-wide airborne-lidar measurements collected by the National Aeronautics and Space Administration High-Spectral Resolution Lidar-2 instrument over Houston, Texas during the September 2021 Tracking Aerosol Convection ExpeRiment–Air Quality campaign alongside surface-monitoring and ozone-sonde measurements to examine ozone diurnal variability within a city. In situ ground measurements and lidar subcolumns were well correlated (<i>r</i> = 0.87) with 2× larger differences observed in the morning than afternoon reflecting the impacts of chemical titration at the surface. Matched ozone-sonde and airborne-lidar subcolumns are also well correlated (<i>r</i> = 0.96, bias = 1.3 ppb) suggesting biases between surface and subcolumn ozone reflect vertical distribution variability not instrument biases. Finally, if the Tropospheric Emissions: Monitoring of Pollution instrument achieves its precision requirement, we find this product may be able to detect enhanced ozone over a city like Houston with up to 55% of near-surface subcolumns capturing ozone variability, particularly during exceedance events.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 6","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD042916","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143698737","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":"Direct Measurements and Implications of the Aerosol Asymmetry Parameter in Wildfire Smoke During FIREX-AQ","authors":"A. T. Ahern,&nbsp;C. A. Brock,&nbsp;M. Lyu,&nbsp;K. Slovacek,&nbsp;R. H. Moore,&nbsp;D. M. Murphy","doi":"10.1029/2024JD042091","DOIUrl":"https://doi.org/10.1029/2024JD042091","url":null,"abstract":"<p>We present direct measurements of the asymmetry parameter (<i>g</i>) from biomass burning aerosol at two wavelengths using the Laser Imaging Nephelometer. We compare the measurements with Mie theory calculations based on optically measured size distributions and with <i>g</i> values derived from hemispheric backscatter (<i>b</i>) measurements using both an integrating and an imaging nephelometer. During the FIREX-AQ field mission, we measured the optical and microphysical properties of smoke plumes that had been emitted between 0.5 and 8.5 hr earlier. We find that the measured <i>g</i> can only be reproduced from particle size distribution measurements using a higher refractive index than is typically retrieved from remote measurements and assumed in some models. Retrievals performed using the GRASP algorithm suggest the refractive index is wavelength-dependent with <i>n</i> = 1.55 ± 0.03 at <i>λ</i> = 660 nm and (1.63 ± 0.04) at <i>λ</i> = 405 nm. Using a simple radiative transfer equation, we show that the instantaneous aerosol cooling of the planet by fresh smoke is increased by 20% when evaluated using the measured <i>g</i> values instead of assuming <i>n</i> = 1.52. Besides improving model representations of radiative cooling by fresh smoke, using a more accurate aerosol optical model can improve retrievals of aerosol microphysical properties from remote sensing techniques. Better retrievals will provide a more accurate constraint on the emissions inventories used in global and regional models. This will ultimately reduce the uncertainty in radiative forcing associated with the increasing frequency and magnitude of wildfires.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 6","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD042091","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143699021","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":"Seasonality and Albedo Dependence of Cloud Radiative Forcing in the Upper Colorado River Basin","authors":"William Rudisill,&nbsp;Daniel Feldman,&nbsp;Christopher J. Cox,&nbsp;Laura Riihimaki,&nbsp;Joseph Sedlar","doi":"10.1029/2024JD042366","DOIUrl":"https://doi.org/10.1029/2024JD042366","url":null,"abstract":"<p>Mountains create and enhance their own clouds, which both scatter and absorb shortwave radiation from the sun and absorb and re-emit land surface and atmospheric longwave radiation. However, the impacts of clouds on the surface radiation balance in high elevation snowy mountain terrain are poorly explored. In this study, we use data collected by the SAIL field campaign and partner organizations in the upper elevations (2,880 m.a.s.l) of the Upper Colorado River Basin (UCRB) over a 21-month period from September 2021 to June 2023 to estimate Cloud Radiative Forcing (CRF) in the shortwave, longwave, and the net effect. Longwave warming effects dominate during the winter when snow albedos are high (0.8–0.9) and the background atmospheric precipitable water vapor is low (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>&lt;</mo>\u0000 </mrow>\u0000 <annotation> ${&lt; } $</annotation>\u0000 </semantics></math>0.5 cm), yielding a maximum monthly average net CRF of +34.7 W·m⁻², meaning that clouds increase the net radiation relative to clear skies during this time period. The sign of net CRF switches in the warm season as snow recedes, sun-angles increase, and the North American monsoon arrives, yielding a minimum monthly average net CRF of −47.6 W·m⁻² with hourly minima of −600 W·m⁻². The sign of net CRF is typically positive, even at solar noon, when the surface is snow covered, except for a brief period over melting, low-albedo snow (0.5–0.6) impacted by dust impurities. Sensitivity tests elucidate the role of the surface albedo on the net CRF. The results suggest that net CRF will increase in magnitude and lead to a more persistent cooling effect on the surface net radiation budget as the snow cover declines.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 6","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD042366","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143698839","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":"Implementation and Evaluation of Physics-Driven Dynamic Entrainment-Mixing Parameterization in a Climate Model and Its Impact on Low-Cloud Simulation","authors":"Xin He,&nbsp;Chunsong Lu,&nbsp;Yangang Liu,&nbsp;Yannian Zhu,&nbsp;Yiran Peng,&nbsp;Lei Zhu,&nbsp;Xiaoqi Xu,&nbsp;Shi Luo,&nbsp;Hengqi Wang,&nbsp;Te Li,&nbsp;Junjun Li,&nbsp;Hao Wang,&nbsp;Sinan Gao,&nbsp;Yuhao Lin","doi":"10.1029/2024JD041918","DOIUrl":"https://doi.org/10.1029/2024JD041918","url":null,"abstract":"<p>The turbulent entrainment-mixing process in the Community Earth System Model version 1.2 (CESM1.2) is assumed to follow the extremely inhomogeneous entrainment-mixing. However, different entrainment-mixing scenarios can occur in real clouds. To address this deficiency, a unifying parameterization that represents different entrainment-mixing processes is implemented and evaluated in CESM1.2. The results indicate that the homogeneous mixing degree values simulated by the new parameterization in CESM1.2 are predominantly greater than 50%, suggesting a tendency toward homogeneous mixing. Compared to the extremely inhomogeneous mixing mechanism, the new parameterization increases the cloud droplet number concentration (<i>N</i>_c). More importantly, the new parameterization improves low-cloud fraction (CLDLOW) simulation in Northwest Pacific (NWP) and Southeast Pacific (SEP) regions, with relative improvements of 2.95% and 4.17%, respectively. Furthermore, the improvements reach up to 44.6% and 16.2% in the NWP and SEP regions, respectively, when considering the relationship between <i>N</i>_c and CLDLOW. Further analysis reveals that the new parameterization enhances cloud optical depth, longwave radiative cooling effect, net condensation rate, cloud water mixing ratio, lower-troposphere stability, and CLDLOW by increasing <i>N</i>_c. These results underscore the importance of improving entrainment-mixing parameterization in climate models.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 6","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143698727","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":"Observation of Gravity Waves Generated by Convection and the “Moving Mountain” Mechanism During Stratéole-2 Campaigns and Their Impact on the QBO","authors":"Milena Corcos,&nbsp;Martina Bramberger,&nbsp;M. Joan Alexander,&nbsp;Albert Hertzog,&nbsp;Chuntao Liu,&nbsp;Corwin Wright","doi":"10.1029/2024JD041804","DOIUrl":"https://doi.org/10.1029/2024JD041804","url":null,"abstract":"<p>Convective gravity waves are important for the forcing of the quasi biennial oscillation (QBO). There is a wave component that is stationary with respect to the convective cells that is triggered by convection acting like a barrier to the background flow (moving mountain mechanism). Waves from this mechanism have only been observed in a few case studies and are not parameterized in climate models. However, the representation of the whole spectrum of gravity waves is crucial for the simulation of the QBO, especially in the lowermost stratosphere (below 50 hPa) where the QBO amplitudes are under-estimated in current global circulation models. In this study, we present analysis of convective gravity wave observations from superpressure balloons in boreal winter 2019 and 2021, retrieving phase speeds, momentum fluxes, and drag. We also identify waves generated by the moving mountain mechanism using the theory of the Beres scheme as a basis. These waves do not have a specific period, but are of smaller horizontal scale, on average around 300 km, which is similar to the scale of convective systems. Our results show that gravity waves contribute up to 2/3 to the QBO forcing below 50 hPa and waves from the moving mountain mechanism are responsible for up to 10% of this forcing.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 6","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD041804","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143698729","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":"Supercooled Liquid Water at the Top of a Snow-Producing Nimbostratus Cloud and Its Association With Gravity Wave Breaking and Turbulence: An IMPACTS Case Study","authors":"Mei Han,&nbsp;Scott A. Braun,&nbsp;Timothy Lang,&nbsp;Matthew L. Walker Mclinden,&nbsp;Gerald M. Heymsfield,&nbsp;Lihua Li,&nbsp;Kenneth L. Thornhill","doi":"10.1029/2024JD041795","DOIUrl":"https://doi.org/10.1029/2024JD041795","url":null,"abstract":"<p>Supercooled liquid water (SLW) at the top of a snow-producing nimbostratus cloud was thoroughly characterized with remote-sensing and in situ measurements during the NASA Investigation of Microphysics and Precipitation for Atlantic Coast-Threatening Snowstorms (IMPACTS) field campaign on 30 January 2022. With three coordinated flight legs, airborne downward-looking cloud radar and lidar and in situ microphysics and wind probes provided a comprehensive depiction of the cloud system over a one-hour period. NASA Cloud Physics Lidar (CPL) measurements suggest that the SLW layer was greater than several hundred meters thick and ∼100 km long within the sampling window. The in situ cloud probes measured a maximum liquid water content (LWC) of 0.58 g m⁻³. NASA Cloud Radar System (CRS) reflectivity and Doppler data revealed gravity waves within the nimbostratus below a strong temperature inversion that was caused by warm air advection near an occluded front in an extratropical cyclone. The enhanced CRS Doppler spectrum width indicated turbulence that was likely generated by gravity wave breaking while propagating upward. Analyses of the Brunt–Väisälä frequency and the Richardson number with NOAA High Resolution Rapid Refresh (HRRR) model supported the observed gravity wave activity. The eddy dissipation rate (EDR) was calculated from both the CRS spectrum width and the in situ wind measured by the Turbulent Air Motion Measurement Systems (TAMMS) to quantify the magnitudes of turbulence and to provide a promising intercomparison between the remote-sensing and in situ turbulence data. A moderate correlation between in situ EDR and LWC suggests that the turbulence likely contributed to the SLW cloud top.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 6","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143698728","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":"Mechanism of Turbulence Structure Evolution in the Nocturnal Boundary Layer During the Interaction of Low-Level Jet and Internal Gravity Waves: Based on Full Boundary Layer Turbulence Observations","authors":"Jie Ding,&nbsp;Yan Ren,&nbsp;Hongsheng Zhang,&nbsp;Heying Chang,&nbsp;Zeyong Hu,&nbsp;Jiening Liang,&nbsp;Kaijun Zhang,&nbsp;Shujin Wang,&nbsp;Xianjie Cao,&nbsp;Pengfei Tian,&nbsp;Lei Zhang","doi":"10.1029/2024JD042106","DOIUrl":"https://doi.org/10.1029/2024JD042106","url":null,"abstract":"<p>In a stable boundary layer (SBL), turbulence is generally weak and exhibits significant intermittent characteristics. Interactions among motions of different scales complicate its structural evolution, making prediction challenging. This study focuses on two typical processes in the SBL: low-level jet (LLJ) and internal gravity waves (IGWs), investigating how their interactions influence the evolution of turbulence structures. Utilizing a full boundary layer turbulence observation network and data processing system at Zhongchuan International Airport, this study includes eddy covariance system, Doppler Lidar, and wind profiling radar. In strongly SBL, turbulence energy accumulates in higher layers and, during downward transfer, generates local LLJ and IGWs, triggering intermittent turbulence events. Internal factors of turbulence intermittency dominated the process. The interaction between LLJ and IGWs maintains intermittent turbulence bursts, accompanied by the conversion of sub-mesoscale energy to turbulent energy. In weakly SBL, the conversion of sub-mesoscale motion energy drives intermittent turbulence events, along with energy transfers between different scales of IGWs, resulting in weaker turbulence intermittency. External factors of turbulence intermittency dominated the process. In both cases, the interaction between LLJ and IGWs alters turbulence structure and atmospheric stability. Turbulent mixing changes the mean gradient field, further influencing the LLJ height. This study elucidates the mechanisms of interaction between internal and external factors in turbulence intermittency. It outlines energy transfer among different scales of motion and clarifies the mechanisms behind state transitions and structural evolution in strongly and weakly SBL. These findings are significant for advancing theoretical research and simulation developments of the SBL.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 6","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD042106","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143698881","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}