Journal of Geophysical Research: Atmospheres最新文献_第3页

Uncovering Below Cloud Rain-Vapor Interactions During Tropical Rain Events Through Simultaneous and Continuous Real-Time Monitoring of Rain and Vapor Isotopes 通过同时和连续实时监测雨水和水汽同位素，揭示热带降雨过程中云层以下雨水和水汽之间的相互作用

IF 3.8 2区地球科学

Journal of Geophysical Research: Atmospheres Pub Date : 2024-11-12 DOI: 10.1029/2023JD040084

Shaoneng He, Dominik Jackisch, Lujia Feng, Dhrubajyoti Samanta, Xianfeng Wang, Nathalie F. Goodkin

{"title":"Uncovering Below Cloud Rain-Vapor Interactions During Tropical Rain Events Through Simultaneous and Continuous Real-Time Monitoring of Rain and Vapor Isotopes","authors":"Shaoneng He, Dominik Jackisch, Lujia Feng, Dhrubajyoti Samanta, Xianfeng Wang, Nathalie F. Goodkin","doi":"10.1029/2023JD040084","DOIUrl":"https://doi.org/10.1029/2023JD040084","url":null,"abstract":"Due to limited water vapor measurements, vapor isotopes have been traditionally estimated under the assumption of isotopic equilibrium between rain and vapor below cloud base. However, recent advancements in analytical instruments allow more vapor isotopic measurements that have challenged this assumption. To enhance our understanding of rain-vapor interactions below cloud base in tropical regions, we established an automated system to measure rain and vapor isotopes simultaneously and continuously in real time at minute intervals in Singapore. Among 324 rain events monitored from 2016 to 2019, 81% exhibited a substantial departure of rain and vapor isotopes from the expected equilibrium. This departure suggests that raindrop evaporation plays a larger role in determining their isotopes. The conclusion is supported by the generally lower slopes of the local meteoric water line. Seasonal variations in rain event characteristics indicate changing influences of rain-vapor interactions: during monsoons, more frequent heavy rainfall maintains relatively high humidity below cloud base, favoring rain-vapor isotopic equilibrium, whereas during inter-monsoons, more light rain events lead to pronounced rain evaporation and larger isotopic differences. Furthermore, rain-vapor interactions below cloud base significantly modulated their isotope evolution during individual events. As events progressed, reduced humidity favored evaporation, increasing rain isotope values and decreasing its d-excess, whereas vapor isotope values decreased and its d-excess increased. Our study introduces a new approach to capturing real-time high-resolution rain and vapor isotopes at minute intervals to understand the dynamics of rain-vapor interactions below cloud base. Findings underscore the crucial role of these interactions in influencing rain and vapor isotopes during tropical rain events.","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"129 22","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142641733","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}

引用次数: 0

Monitoring Heavy Rainfall Events in East Asia Using High-Resolution Isotopic Observations 利用高分辨率同位素观测监测东亚暴雨事件

IF 3.8 2区地球科学

Journal of Geophysical Research: Atmospheres Pub Date : 2024-11-12 DOI: 10.1029/2024JD041783

Tao Xu, Hongxi Pang, Shuangye Wu, Huiwen Guo, Wangbin Zhang, Shugui Hou

{"title":"Monitoring Heavy Rainfall Events in East Asia Using High-Resolution Isotopic Observations","authors":"Tao Xu, Hongxi Pang, Shuangye Wu, Huiwen Guo, Wangbin Zhang, Shugui Hou","doi":"10.1029/2024JD041783","DOIUrl":"https://doi.org/10.1029/2024JD041783","url":null,"abstract":"It is important to understand the mechanisms of heavy rainfall events, as such information could improve forecasting of these events and help mitigate their adverse impacts on life and property. In this study, we analyzed hourly stable isotopic compositions in water vapor (δ18Ov and d-excessv) during heavy rainfall events in the summer monsoon season (June to September) from 2013 to 2023 in Nanjing, eastern China. These data were extracted from the longest data set of high-resolution and continuous in situ observations of water vapor isotopes globally. Based on these data, we identified four evolution patterns of δ18Ov during heavy rainfall events, corresponding to different weather systems: slow-declining (tropical cyclone interacting with mid- and high-latitude system), W-shaped (tropical cyclone), U-shaped (cold vortex system), and inclined L-shaped (upper-level trough system). The isotopic variations suggest that heavy rainfall events in eastern China were mainly sustained by moisture from adjacent oceans (including the South China Sea and the East China Sea) and terrestrial environment rather than from the distant Indian Ocean as previously suggested. In addition, for some heavy rainfall events with an intermittent period, the nearby oceanic moisture transport alters before and after the intermittent period due to an intensity change or overall transition of low-level weather systems. This study serves as a benchmark for tracing heavy rainfall processes in East Asia using high-resolution water vapor isotopes.","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"129 22","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142641732","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}

引用次数: 0

Contributions of Stationary and Transient Water Vapor Transports to the Extreme Precipitation Changes Over the Tibetan Plateau 静态和瞬态水汽传输对青藏高原极端降水变化的贡献

IF 3.8 2区地球科学

Journal of Geophysical Research: Atmospheres Pub Date : 2024-11-12 DOI: 10.1029/2024JD040966

Shijia Liu, Tianjun Zhou, Jie Jiang, Liwei Zou, Lixia Zhang, Wenxia Zhang, Linqiang He

{"title":"Contributions of Stationary and Transient Water Vapor Transports to the Extreme Precipitation Changes Over the Tibetan Plateau","authors":"Shijia Liu, Tianjun Zhou, Jie Jiang, Liwei Zou, Lixia Zhang, Wenxia Zhang, Linqiang He","doi":"10.1029/2024JD040966","DOIUrl":"https://doi.org/10.1029/2024JD040966","url":null,"abstract":"The Tibetan Plateau (TP) has experienced “south drying-north wetting” extreme precipitation changes over the past half century. The effects of water vapor transport at different timescales on TP extreme precipitation changes remain unexplored. Here, we utilize the reanalysis data sets to quantify the contributions of stationary and transient processes of water vapor transport to the long-term changes in the extreme precipitation (R95p) during wet season (Jun-Jul-Aug-Sep) over the TP and surrounding regions. We find that the daily scale transient processes dominate the dipole trend of extreme precipitation with a contribution of 55.1% in the northern and 79.5% in the southern TP, respectively, whereas the contribution of monthly scale stationary processes is of 19.0% and 20.5%. The long-term changes in extreme precipitation are dominated by the transient dynamic component. We identified the synoptic circulation patterns affecting the changes of R95p over the northern and southern TP by using k-means clustering. The patterns featured with a 500 hPa trough, 200 hPa wind divergence and low transient geopotential height are identified. The frequency of the dominant circulation patterns increases in the northern TP and decreases in the southern TP, which leads to the dipolar changes of extreme precipitation over the TP and surrounding regions.","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"129 22","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142641741","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}

引用次数: 0

Transport of Exogenous Anthropogenic Atmospheric Mercury to the Tibetan Plateau Identified Using Mercury Stable Isotopes 利用汞稳定同位素确定外源人为大气汞向青藏高原的迁移情况

IF 3.8 2区地球科学

Journal of Geophysical Research: Atmospheres Pub Date : 2024-11-09 DOI: 10.1029/2024JD041684

Kaihui Tang, Xiufeng Yin, Hui Zhang, Xuewu Fu, Hui Zhang, Leiming Zhang, Qianggong Zhang, Pengfei Chen, Longyu Jia, Benjamin de Foy, Shichang Kang, Xinbin Feng

{"title":"Transport of Exogenous Anthropogenic Atmospheric Mercury to the Tibetan Plateau Identified Using Mercury Stable Isotopes","authors":"Kaihui Tang, Xiufeng Yin, Hui Zhang, Xuewu Fu, Hui Zhang, Leiming Zhang, Qianggong Zhang, Pengfei Chen, Longyu Jia, Benjamin de Foy, Shichang Kang, Xinbin Feng","doi":"10.1029/2024JD041684","DOIUrl":"https://doi.org/10.1029/2024JD041684","url":null,"abstract":"Transport of exogenous anthropogenic mercury (Hg) is an important source of Hg pollution in the Tibetan Plateau (TP) and its downstream water ecosystems, but the origins and contributions of Hg sources remain uncertain. Here, we investigate the concentrations and isotopic compositions of gaseous elemental mercury (GEM) at four rural sites in the TP and three urban sites surrounding the TP to quantify the sources of GEM in the TP. GEM concentrations in the surrounding cities (site-specific means: 2.36–9.12 ng m−3) were highly elevated mainly due to strong local anthropogenic emissions as indicated by their negative δ202Hg and near zero Δ199Hg and Δ200Hg signatures. GEM isotopes indicate that GEM pollution in the TP, typically observed during the summer monsoon and the pre-monsoon, were mainly caused by trans-boundary transport of anthropogenic Hg from surroundings. Using an Hg isotope mixing model, we estimate that exogenous anthropogenic emissions on average contributed 26 ± 5% (1sd) to the GEM in the TP. Further analysis of the transport of anthropogenic Hg emissions based on the backward trajectory and gridded anthropogenic Hg emissions suggests that 16 ± 9% and 6 ± 13% of the GEM in the TP were derived from anthropogenic sources in South Asia and China, respectively. Our study suggests that anthropogenic Hg emissions in South Asia could be effectively transported to the TP across the Himalayan range. Future studies are needed to better assess the role of rapidly increasing anthropogenic Hg emissions in South Asia on the regional to global scale atmospheric Hg cycling.","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"129 21","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142641591","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}

引用次数: 0

Better Resolved Orography Improves Precipitation Simulation Over the Tibetan Plateau in High-Resolution Models 分辨率更高的地貌图改进了高分辨率模型对青藏高原降水的模拟

IF 3.8 2区地球科学

Journal of Geophysical Research: Atmospheres Pub Date : 2024-11-09 DOI: 10.1029/2024JD041140

Xiaolong Chen, Tianjun Zhou, Peili Wu, Malcolm J. Roberts

{"title":"Better Resolved Orography Improves Precipitation Simulation Over the Tibetan Plateau in High-Resolution Models","authors":"Xiaolong Chen, Tianjun Zhou, Peili Wu, Malcolm J. Roberts","doi":"10.1029/2024JD041140","DOIUrl":"https://doi.org/10.1029/2024JD041140","url":null,"abstract":"Regarded as the Asian Water Tower, the Tibetan Plateau (TP) collects atmospheric precipitation from a vast area of land and feeds into major rivers that sustain the livelihood of billions of people in East, South and Central Asia. It is critical to reasonably simulate the hydrological cycle over the TP in order to assess future climate risks to agriculture, water resources and ecosystem services. To address the chronic wet biases over the TP in state-of-the-art climate models, we have compared 12 high-resolution (HR) climate models (25–50 km) to their corresponding low-resolution versions (100–200 km) with respect to the 1979–2014 climatology. It is found that the HR models consistently reduce about half of the wet biases over the TP, mainly from better resolved orography. The wet biases are reduced by 41% over the northern and western TP, mainly contributed by decreased frequency of light precipitation (0.1–10 mm day−1), which is attributed to reduced evaporation because of weakened surface wind by raised orography. The most significant reduction of biases (53%) rising from decreased frequency of mid-heavy precipitation (10–50 mm day−1), appears over the southern and eastern TP, on the leeside of elevated orography where steeper orography enhances rain shadow effect by stronger downward motion along the sharper slope, while partly compensated by air column convergence due to vertical stretching of the downward flow for potential vorticity conservation. This study highlights the importance of surface processes and resolving complex orography in simulating precipitation and large-scale hydrology around the TP which potentially benefits the future hydrological projection.","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"129 21","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142641590","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}

引用次数: 0

Assessing Radiative Feedbacks and Their Contribution to the Arctic Amplification Measured by Various Metrics 评估辐射反馈及其对通过各种指标测量的北极放大效应的贡献

IF 3.8 2区地球科学

Journal of Geophysical Research: Atmospheres Pub Date : 2024-11-09 DOI: 10.1029/2024JD040880

Yiling Huo, Hailong Wang, Jian Lu, Qiang Fu, Alexandra K. Jonko, Younjoo J. Lee, Weiming Ma, Wieslaw Maslowski, Yi Qin

{"title":"Assessing Radiative Feedbacks and Their Contribution to the Arctic Amplification Measured by Various Metrics","authors":"Yiling Huo, Hailong Wang, Jian Lu, Qiang Fu, Alexandra K. Jonko, Younjoo J. Lee, Weiming Ma, Wieslaw Maslowski, Yi Qin","doi":"10.1029/2024JD040880","DOIUrl":"https://doi.org/10.1029/2024JD040880","url":null,"abstract":"Arctic amplification (AA), characterized by a more rapid surface air temperature (SAT) warming in the Arctic than the global average, is a major feature of global climate warming. Various metrics have been used to quantify AA based on SAT anomalies, trends, or variability, and they can yield quite different conclusions regarding the magnitude and temporal patterns of AA. This study examines and compares various AA metrics for their temporal consistency in the region north of 70°N from the early twentieth to the early 21st century using observational data and reanalysis products. We also quantify contributions of different radiative feedback mechanisms to AA based on short-term climate variability in reanalysis and model data using the Kernel-Gregory approach. Albedo and lapse rate feedbacks are positive and comparable, with albedo feedback being the leading contributor for all AA metrics. The net cloud feedback, which has large uncertainties, depends strongly on the data sets and AA metrics used. By quantifying the influence of internal variability on AA and related feedbacks based on global climate model ensemble simulations, we find that water vapor and cloud feedbacks are most heavily affected by internal variability.","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"129 21","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD040880","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142641587","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}

引用次数: 0

Stratus and Stratocumulus Cloud Microphysics and Drizzle Relationships With CCN Modality 层云和层积云微物理和细雨与 CCN 模式的关系

IF 3.8 2区地球科学

Journal of Geophysical Research: Atmospheres Pub Date : 2024-11-07 DOI: 10.1029/2024JD041965

James G. Hudson, Stephen Noble

{"title":"Stratus and Stratocumulus Cloud Microphysics and Drizzle Relationships With CCN Modality","authors":"James G. Hudson, Stephen Noble","doi":"10.1029/2024JD041965","DOIUrl":"https://doi.org/10.1029/2024JD041965","url":null,"abstract":"High resolution extended-range cloud condensation nuclei (CCN) spectral comparisons with cloud microphysics and drizzle of the Physics of Stratocumulus Tops (POST) field experiment confirmed results in the Marine Stratus/Stratocumulus Experiment (MASE). Both of these stratus cloud projects demonstrated that bimodal CCN spectra typically caused by cloud processing were associated with clouds that exhibited higher concentrations of smaller droplets with narrower distributions and less drizzle than clouds associated with unimodal CCN spectra. Resulting brighter clouds and increased cloudiness could enhance both indirect aerosol effects (IAE). These stratus findings are opposite of analogous measurements in two cumulus cloud projects, which showed bimodal CCN associated with fewer larger droplets more broadly distributed and with more drizzle than clouds associated with unimodal CCN. Resulting reduced cumulus brightness and cloudiness could reduce both IAE. Physics of Stratocumulus Tops (POST) flights in air masses with higher CCN concentrations, NCCN, showed more extremes of the stratus characteristics. However, POST flights with lower NCCN showed opposite droplet characteristics similar to the cumulus clouds, yet still showed less drizzle in clouds associated with bimodal CCN, but not as much less as the flights with higher NCCN. Since all MASE clouds were in polluted air masses, while the two cumulus projects were in clean air masses we deduce from these four projects that both the dynamic stratus/cumulus differences (vertical wind) and NCCN are responsible for the microphysics and drizzle differences among these projects. This is because the clean POST characteristics are a hybrid between MASE/POST high NCCN and the two cumulus projects.","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"129 21","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD041965","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142641150","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}

引用次数: 0

Intensification of an Autumn Tropical Cyclone by Offshore Wind Farms in the Northern South China Sea 南海北部近海风电场对秋季热带气旋的强化作用

IF 3.8 2区地球科学

Journal of Geophysical Research: Atmospheres Pub Date : 2024-11-07 DOI: 10.1029/2024JD041489

Shaokun Deng, Shengli Chen, Yi Sui, Zhen-Zhong Hu

{"title":"Intensification of an Autumn Tropical Cyclone by Offshore Wind Farms in the Northern South China Sea","authors":"Shaokun Deng, Shengli Chen, Yi Sui, Zhen-Zhong Hu","doi":"10.1029/2024JD041489","DOIUrl":"https://doi.org/10.1029/2024JD041489","url":null,"abstract":"The rapid development of the wind industry is accompanied by increasing environmental impacts. Currently, there is a lack of research on the impacts of offshore wind farm (OWF) on tropical cyclone (TC) intensity, including the mechanisms involved. This research is carried out by using a coupled and an uncoupled numerical model to investigate the impact of OWF on an autumn TC in the northeastern South China Sea. The results show that the wind speed deficit caused by OWF leads to an increase in surface pressure on the inflow side. This causes the surface pressure in the TC periphery to increase by advection, even if the TC is some distance away from the OWF. The increase in pressure gradient from the periphery to the TC center enhances the TC secondary circulation, thereby intensifying the TC. When the TC enters the OWF, the above mechanisms weaken and the ocean dominates the TC intensification. This is because the reduction in wind speed caused by the OWF results in a weaker sea surface current velocity, which weakens the flow of upstream cold water into the OWF, warming the sea surface temperature (SST) within the OWF. This implies that the horizontal gradient of the local SST is an important factor to be considered in the development of OWF. Sensitivity experiments indicate that OWF can also intensify other types of TC, and that higher cut-out wind speeds lead to stronger intensification effects. These results also provide a new perspective on TC intensity forecasts.","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"129 21","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142641151","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}

引用次数: 0

Processes Driving the Intermodel Spread of the Southern Hemisphere Hadley Circulation Expansion in CMIP6 Models CMIP6 模型中驱动南半球哈德利环流扩张模型间扩展的过程

IF 3.8 2区地球科学

Journal of Geophysical Research: Atmospheres Pub Date : 2024-11-06 DOI: 10.1029/2024JD041726

Ije Hur, Changhyun Yoo, Sang-Wook Yeh, Young-Ha Kim, Kyong-Hwan Seo

{"title":"Processes Driving the Intermodel Spread of the Southern Hemisphere Hadley Circulation Expansion in CMIP6 Models","authors":"Ije Hur, Changhyun Yoo, Sang-Wook Yeh, Young-Ha Kim, Kyong-Hwan Seo","doi":"10.1029/2024JD041726","DOIUrl":"https://doi.org/10.1029/2024JD041726","url":null,"abstract":"The Hadley circulation (HC) has been expanding poleward in recent decades. The Coupled Model Intercomparison Project Phase 6 (CMIP6) models predict that the expansion will accelerate in the future, more so in the Southern Hemisphere (SH). However, the extent of the expansion varies widely among the models. We investigate the mechanisms driving the intermodel spread in SH HC expansion predictions. The intermodel spread is obtained by an empirical orthogonal function analysis on the SH HC trend patterns of 16 CMIP6 model simulations using the historical and shared socioeconomic pathway 5–8.5 scenarios. The leading mode, showing a mean meridional stream function anomaly at the poleward SH HC extent, explains 49.73% of the variance and significantly correlates (r = 0.94) with the SH HC expansion. By analyzing the extended Kuo-Eliassen equation, we find that the intermodel difference in the representation of diabatic heating is responsible for about 14% of the intermodel spread. The meridional eddy momentum and heat fluxes contribute to about 21% and 18% of the intermodel spread, respectively. The models simulating a relatively large SH HC expansion tend to show increased precipitation in the Southern Pacific Convergence Zone, reduced baroclinic instability in the subtropics, and an enhanced poleward shift of jet stream in the midlatitudes. This suggests that the uncertainty in the HC projection may be constrained by reducing the bias in the trend of the mean fields.","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"129 21","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD041726","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142641337","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}

引用次数: 0

Observed Responses of Gravity Wave Momentum Fluxes to the Madden‒Julian Oscillation Around the Extratropical Mesopause Using Mohe Meteor Radar Observations 利用 Mohe 流星雷达观测数据观测到的重力波动量通量对热带外中层顶附近马登-朱利安涛动的响应

IF 3.8 2区地球科学

Journal of Geophysical Research: Atmospheres Pub Date : 2024-11-06 DOI: 10.1029/2024JD041447

Xu Zhou, Libo Liu, Xinan Yue, Guiwan Chen, Xian Lu

{"title":"Observed Responses of Gravity Wave Momentum Fluxes to the Madden‒Julian Oscillation Around the Extratropical Mesopause Using Mohe Meteor Radar Observations","authors":"Xu Zhou, Libo Liu, Xinan Yue, Guiwan Chen, Xian Lu","doi":"10.1029/2024JD041447","DOIUrl":"https://doi.org/10.1029/2024JD041447","url":null,"abstract":"The 12-year continuous observation of gravity wave momentum fluxes (GWMFs) estimated by the Mohe meteor radar (53.5°N, 122.3°E) revealed prominent intraseasonal variability around the extratropical mesopause (82–94 km) during boreal winters. Composite analysis of the December‒January‒February (DJF) season according to the Madden‒Julian Oscillation (MJO) phases revealed that the zonal GWMFs notably increased in MJO Phase 4 (P4) by ∼2–4 m2/s2, and a Monte Carlo test was designed to examine the statistical significance. The response in zonal winds lags behind the GWMF response by two MJO phases (i.e., 1/2π), indicating a “force‒response” interaction between them. Additionally, time-lagged composites revealed that strengthened westward GWMFs occurred ∼25–35 days after MJO P4, coincident with the MJO impact on the zonal winds in the stratosphere. The analysis results also suggested that the mechanism of MJO by which the MJO influences the stratospheric circulation might involve poleward propagating effects of stationary planetary waves with zonal wavenumber one. This work emphasizes the importance of GW intraseasonal variability, which impacts tropical sources from the troposphere to the extratropical mesopause.","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"129 21","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD041447","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142641339","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}

引用次数: 0