Journal of Geophysical Research: Atmospheres最新文献

Recent Changes in Hemispheric Asymmetry of Stratospheric Water Vapor

IF 3.8 2区地球科学

Journal of Geophysical Research: Atmospheres Pub Date : 2025-04-25 DOI: 10.1029/2024JD043022

Jingyuan Xu, Mengchu Tao, Jianchun Bian, Dan Li, Paul Konopka, Felix Ploeger

{"title":"Recent Changes in Hemispheric Asymmetry of Stratospheric Water Vapor","authors":"Jingyuan Xu, Mengchu Tao, Jianchun Bian, Dan Li, Paul Konopka, Felix Ploeger","doi":"10.1029/2024JD043022","DOIUrl":"https://doi.org/10.1029/2024JD043022","url":null,"abstract":"Stratospheric moistening after 2000, with a more pronounced trend in the Northern Hemisphere (NH), has been detected through satellite, in situ observations, and model simulations. This study aims to provide an updated analysis of the hemispheric asymmetry of stratospheric water vapor (SWV) for the period from 2000 to 2020 based on merged satellite data set and Chemical Lagrangian Model of the Stratosphere (CLaMS) simulations driven by ERA5. Over post-2000 decades, significant changes were identified in comparison to the pre-2000 period, notably a reversal in the SWV difference between the Northern and Southern Hemispheres, particularly in the midlatitudes. This shift is largely attributed to a slowdown in the deep branch of Brewer-Dobson circulation (BDC) in the Northern Hemisphere relative to the Southern Hemisphere after about year 2000. The cooling-induced dehydration is the primary driver of the significantly lower SWV values in the Antarctic stratosphere than the Arctic stratosphere. This asymmetry increased before 2000 at a rate of 0.1–0.2 ppmv per decade. After 2000, however, this difference has decreased, primarily due to ozone recovery in the Southern Hemisphere, despite the enhanced northward transport of water vapor driven by the changes in the BDC. The study emphasizes the growing need for long-term SWV monitoring in the Southern Hemisphere to better understand global water vapor dynamics.","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 8","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143871725","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

The Cold Biases in the Soil and Surface Air Temperature Simulations of RegCM4.7 Model Over the Tibetan Plateau in Cold Seasons Reduced by Adopting an Improved Snow Cover Fraction Scheme

IF 3.8 2区地球科学

Journal of Geophysical Research: Atmospheres Pub Date : 2025-04-25 DOI: 10.1029/2025JD043507

Jiangxin Luo, Anning Huang, Xingwen Jiang, Meng Xu, Xin Miao, Chunlei Gu, Xinsheng Zhu

{"title":"The Cold Biases in the Soil and Surface Air Temperature Simulations of RegCM4.7 Model Over the Tibetan Plateau in Cold Seasons Reduced by Adopting an Improved Snow Cover Fraction Scheme","authors":"Jiangxin Luo, Anning Huang, Xingwen Jiang, Meng Xu, Xin Miao, Chunlei Gu, Xinsheng Zhu","doi":"10.1029/2025JD043507","DOIUrl":"https://doi.org/10.1029/2025JD043507","url":null,"abstract":"In cold seasons, global and regional climate models exhibit consistent cold biases in the soil and surface air temperature simulations on the Tibetan Plateau (TP), while the overestimated snow cover fraction (SCF) is treated as one of crucial factors leading to the cold biases. To partially solve this issue, this study adopts an improved SCF scheme that adequately consider the impact of sub-grid terrain relief on snow cover into the Regional Climate Model version 4.7 (RegCM4.7) coupled with the CLM4.5 land surface model to enhance the model skill. Results show that adopting the improved SCF scheme in RegCM4.7 model can significantly reduce the SCF overestimation on the TP produced by the original model, leading to obvious improvements in the surface albedo, soil and surface air temperature simulations in cold seasons. Mechanism analysis indicates that the sub-grid terrain relief suppresses the rapid increase of SCF with snowfall and makes the ground more difficult to be fully covered by snow, resulting in the overestimation of SCF obviously reduced and thereafter the surface albedo decreased. It further causes the ground surface to absorb more solar radiation and then more heat released to the overlying atmosphere and deep soils. Thereafter, the cold biases in the soil and surface air temperature simulations on the TP in cold seasons can be clearly reduced. This study highlights that considering the impact of the sub-grid topography relief on snow cover in numerical models is one of the effective ways for reducing the cold biases on the TP.","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 8","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143871791","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

Urbanization Enhances Shorter-Duration Precipitation Intensity in the Yangtze River Delta Region

IF 3.8 2区地球科学

Journal of Geophysical Research: Atmospheres Pub Date : 2025-04-25 DOI: 10.1029/2024JD043300

Xue Xie, Dajing Qin, Mingzhong Xiao, Kairong Lin

{"title":"Urbanization Enhances Shorter-Duration Precipitation Intensity in the Yangtze River Delta Region","authors":"Xue Xie, Dajing Qin, Mingzhong Xiao, Kairong Lin","doi":"10.1029/2024JD043300","DOIUrl":"https://doi.org/10.1029/2024JD043300","url":null,"abstract":"Understanding the response of extreme precipitation events under urbanization conditions is vital for mitigating the risk of urban flooding. Nevertheless, previous studies assessing the impact of urbanization on extreme precipitation often neglected the role of natural climate variations. To fill this gap, this study aims to investigate how extreme precipitation of varying durations responds to urbanization, accounting for natural climate variations. We classified the urban agglomeration of the Yangtze River Delta (YRD) in East China into nine distinct groups based on seasonal extreme precipitation patterns, utilizing structural self-organizing maps (SOM), and explored the relationship between urbanization and extreme precipitation with Geographical Detector Model. The results revealed substantial seasonal precipitation fluctuations within the YRD, showing significant spatial variability and underscoring the importance of considering natural climate variations in urban extreme precipitation studies. After accounting for natural climate variations, our findings unveiled a notable urbanization-induced precipitation effect, particularly prominent during summer and autumn. Additionally, urbanization's influence on extreme precipitation demonstrated a significant time-scaling effect, with shorter-duration events exhibiting a stronger correlation with urbanization. Furthermore, the interaction between urbanization and elevation surpassed the impact of individual factors, intensifying as event duration decreased, especially for durations less than 3 days, indicating a more complex mechanism for their influence on extreme precipitation. This research aims to enhance our understanding of how urbanization shapes extreme precipitation patterns. These findings are crucial for urban planning and climate adaptation strategies to address the risks associated with heavy precipitation in urban areas.","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 8","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143871484","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

Revisiting the Interaction Between Antarctic Sea Ice and Southern Ocean Cyclones

IF 3.8 2区地球科学

Journal of Geophysical Research: Atmospheres Pub Date : 2025-04-25 DOI: 10.1029/2024JD042914

Rui Zhong, Kevin Hodges, Qinghua Yang, Dake Chen

{"title":"Revisiting the Interaction Between Antarctic Sea Ice and Southern Ocean Cyclones","authors":"Rui Zhong, Kevin Hodges, Qinghua Yang, Dake Chen","doi":"10.1029/2024JD042914","DOIUrl":"https://doi.org/10.1029/2024JD042914","url":null,"abstract":"The seasonal cycle of Antarctic sea ice—characterized by slow advance and rapid retreat—does not align with the seasonal north-south shift of Southern Ocean storm tracks. This misalignment introduces spatial and temporal complexity into cyclone-sea ice interactions. To gain deeper insights, we apply cyclone tracking to identify cyclones near the sea ice edge and examine both their characteristics and the sea ice's response. Our analysis reveals a significant increase in the frequency of these cyclones across most subregions of the Southern Ocean. To quantify their impact, we introduce an exposure index that encompasses cyclone intensity, local sea ice concentration (SIC), and interaction duration to identify key seasons and regions of cyclone-ice interactions. Furthermore, categorizing cyclones by SIC anomalies reveals that cyclone strength and moving direction are primary drivers of SIC variability. In particular, composite analyses highlight surface temperature advection and sensible heat flux as critical mechanisms linking cyclone circulation to SIC anomalies. These findings highlight the role of cyclones in driving short-term sea ice variability, offering new insights into Antarctic climate system feedbacks.","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 8","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143871726","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

Observing the Diurnal Variation of Atmospheric Ozone From the Geostationary Interferometric Infrared Sounder (GIIRS) Over East Asia

IF 3.8 2区地球科学

Journal of Geophysical Research: Atmospheres Pub Date : 2025-04-24 DOI: 10.1029/2024JD042292

Shangyi Liu, Jiancong Hua, Huidong Wang, Shan Han, Lu Lee, Chengli Qi, Feng Lu, Yangcheng Luo, Xiaoyi Zhao, Zhengqiang Li, Sang-Woo Kim, Chang Keun Song, Yugo Kanaya, Arno Keppens, Jean-Christopher Lambert, Cathy Clerbaux, Zhao-Cheng Zeng

{"title":"Observing the Diurnal Variation of Atmospheric Ozone From the Geostationary Interferometric Infrared Sounder (GIIRS) Over East Asia","authors":"Shangyi Liu, Jiancong Hua, Huidong Wang, Shan Han, Lu Lee, Chengli Qi, Feng Lu, Yangcheng Luo, Xiaoyi Zhao, Zhengqiang Li, Sang-Woo Kim, Chang Keun Song, Yugo Kanaya, Arno Keppens, Jean-Christopher Lambert, Cathy Clerbaux, Zhao-Cheng Zeng","doi":"10.1029/2024JD042292","DOIUrl":"https://doi.org/10.1029/2024JD042292","url":null,"abstract":"Ozone is an important atmospheric constituent, exerting a pivotal influence on atmospheric chemistry, air quality, and climate change. The monitoring of its distribution and variation is crucial for advancing our understanding of ozone development and related processes. This study presents the first spatial and temporal distributions of total ozone columns (TOC) retrieved from the Geostationary Interferometric Infrared Sounder (GIIRS), on board China's FengYun-4B satellite (FY-4B/GIIRS) launched in 2021. Particularly, we focus on the variations of TOCs in East Asia from diurnal to seasonal time scales. Retrievals are implemented using spectra from March, June, September, and December, representing different seasons. The results show that the degree of freedom for the signal (DOFS) typically exhibited a range of 0.8–1.4, with the vertical detection sensitivity of GIIRS peaking in the upper troposphere/lower stratosphere (UTLS) region, where the ozone variability is the highest. Collocation comparisons with the Infrared Atmospheric Sounding Interferometer (IASI) retrievals, the Ozone Monitoring Instrument (OMI) measurements, the European Center for Medium-Range Weather Forecasts (ECMWF) Reanalysis v5 (ERA5) simulations, and in situ ozone observations show good agreement. The comparisons of TOCs between GIIRS, Pandora and ERA5 at different latitudes and different time scales demonstrate the ability of FY-4B/GIIRS in capturing the temporal and latitudinal ozone variations, particularly at middle and high latitudes. Our work demonstrates that FY-4B/GIIRS has good capability to track ozone variations from diurnal to seasonal in East Asia, which will contribute to the understanding of regional and global ozone variations.","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 8","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143866046","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

Self-Induced Gravity Wave Attenuation and Breaking With Generation of Secondary Modes in the Lower Mesosphere During Two SOUTHTRAC Flights Above the Andes 在安第斯山脉上空进行的两次 SOUTHTRAC 飞行期间，低层中间层的自诱发重力波衰减和断裂与次级模式的产生

IF 3.8 2区地球科学

Journal of Geophysical Research: Atmospheres Pub Date : 2025-04-24 DOI: 10.1029/2024JD042981

P. Alexander, A. de la Torre, T. Marcos, R. Hierro, N. Kaifler, S. Rhode, M. Geldenhuys

{"title":"Self-Induced Gravity Wave Attenuation and Breaking With Generation of Secondary Modes in the Lower Mesosphere During Two SOUTHTRAC Flights Above the Andes","authors":"P. Alexander, A. de la Torre, T. Marcos, R. Hierro, N. Kaifler, S. Rhode, M. Geldenhuys","doi":"10.1029/2024JD042981","DOIUrl":"https://doi.org/10.1029/2024JD042981","url":null,"abstract":"We combine lidar temperature observations onboard a research aircraft with numerical simulations in the framework of the SOUTHTRAC (Southern Hemisphere Transport, Dynamics, and Chemistry) Campaign. Deep propagation of gravity waves (GW) from the troposphere to the lower mesosphere is studied above the Southern Andes during two flights in September 2019. We use the Weather Research and Forecasting (WRF) model with a configuration for the simulations that has been validated in a previous study of this campaign. Strong orographic GW were detected during both flights that were conceived for different latitudes. The observational and numerical data reveal the presence of significant GW attenuation, breaking and secondary wave generation above the stratopause due to the development of convective and dynamic instability as well as conditions for wave evanescence. The GW generated by topography were not able to alter the stable structure of the stratosphere, but the scenario was quite different in the lower mesosphere. The disturbed zones in that layer were produced by the combined effect on lapse rate of the background temperature variation and the perturbations associated with GW, which together may induce large vertical gradients. As a consequence, areas of reduced stability (with low or even negative buoyancy parameter) emerge above the stratopause. The existence of these GW self-induced attenuation layers in the mesosphere where temperature perturbations produce large negative gradients may lead to an amplitude growth control mechanism for the upward propagating waves.","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 8","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143865970","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

Comparative Evaluation of the Ability of the MYNN-EDMF PBL Scheme in WRF Model to Reproduce Near Surface Wind Speed Over Different Topographical Types 比较评估 WRF 模式中 MYNN-EDMF PBL 方案再现不同地形类型近地面风速的能力

IF 3.8 2区地球科学

Journal of Geophysical Research: Atmospheres Pub Date : 2025-04-24 DOI: 10.1029/2023JD040620

Yunpeng Shan, Yangang Liu, Xin Zhou

{"title":"Comparative Evaluation of the Ability of the MYNN-EDMF PBL Scheme in WRF Model to Reproduce Near Surface Wind Speed Over Different Topographical Types","authors":"Yunpeng Shan, Yangang Liu, Xin Zhou","doi":"10.1029/2023JD040620","DOIUrl":"https://doi.org/10.1029/2023JD040620","url":null,"abstract":"This study systematically evaluates the performance of the Mellor-Yamada-Nakanishi-Niino-Eddy-Diffusion-Mass-Flux planetary boundary layer (PBL) scheme within the Weather Research and Forecasting (WRF) model in simulating near-surface wind speeds across various topographies in New York State (NYS). Simulated wind speeds are compared with in-situ measurements from 22 surface sites, grouped into six topographic categories: continental plain (CT), lakeside (LS), river valley (RV), Long Island (LI), Block Island (BI), and offshore ocean (OO). A quantitative evaluation based on Relative Euclidean Distance shows that wind speeds at the OO site are the most accurately reproduced, followed by those at LI sites, while the model performs less accurately for the remaining topographic groups. Wind speeds over CT sites tend to be overestimated by approximately 1 m/s, although their diurnal variability (DV) is well captured. In contrast, the model underestimates wind DV at LS, RV, LI, and BI sites, with the largest biases occurring at LI and BI, resulting in underestimated daytime wind speed and/or overestimated nighttime wind speed. The OO winds exhibit minimal diurnal variation, accurately captured by our WRF model. The surface wind diurnal variation is closely linked to PBL development. Among the indicators of PBL development, surface potential temperature biases most strongly correlate with wind speed biases. Our WRF model faces challenges in capturing the distinctions between winds influenced by local circulations and those over continental plains, and the significantly stronger winds at OO compared to BI. Potential causes for these biases are discussed, offering pathways for improving surface wind simulations in future.","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 8","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2023JD040620","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143866044","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

Decoupling of Monsoon Dynamics and Thermodynamics Under Global Warming: Evidence From Multi-Proxy Records in a Single Speleothem 全球变暖下季风动力学与热力学的解耦：来自单一洞穴的多重代用记录的证据

IF 3.8 2区地球科学

Journal of Geophysical Research: Atmospheres Pub Date : 2025-04-24 DOI: 10.1029/2024JD042995

Jiayu Lu, Jingyao Zhao, Haiwei Zhang, Hanying Li, Lijuan Sha, Jian Wang, Xiyu Dong, R. Lawrence Edwards, Hai Cheng

{"title":"Decoupling of Monsoon Dynamics and Thermodynamics Under Global Warming: Evidence From Multi-Proxy Records in a Single Speleothem","authors":"Jiayu Lu, Jingyao Zhao, Haiwei Zhang, Hanying Li, Lijuan Sha, Jian Wang, Xiyu Dong, R. Lawrence Edwards, Hai Cheng","doi":"10.1029/2024JD042995","DOIUrl":"https://doi.org/10.1029/2024JD042995","url":null,"abstract":"Speleothem multiproxy records are important for understanding the differences between the dynamic and thermodynamic aspects of the Asian summer monsoon. In this study, we simultaneously provide the seasonally resolved oxygen isotope (δ18Os) and trace element ratio (Mg/Ca, Sr/Ca, and Ba/Ca) records from an actively growing stalagmite from Zhangjia Cave, Sichuan Basin, southwestern China, covering the past ∼130 years. The overall increasing trend in δ18Os indicates a weakening of Asian summer monsoon circulation over the last century, while the trace element ratios suggest a relatively stable precipitation trend. Notably, the correlation between δ18Os and trace element ratios has experienced a significant transition since the acceleration of global warming from the 1970s. Our findings reinforce the notion that the forcing of greenhouse gases weakened monsoon dynamics (circulation) over the past century, whereas the monsoon thermodynamic (precipitation) was essentially unchanged, thus highlighting the different influences of the greenhouse gases on the monsoon dynamics and thermodynamics, respectively.","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 8","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143866003","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

A Comparative Study of Cloud Properties Between Northern and Southern High Latitudes Based on ARM Observations and EAMv2 Simulations

IF 3.8 2区地球科学

Journal of Geophysical Research: Atmospheres Pub Date : 2025-04-24 DOI: 10.1029/2024JD041588

N. Desai, M. Diao, Y. Shi, X. Liu

{"title":"A Comparative Study of Cloud Properties Between Northern and Southern High Latitudes Based on ARM Observations and EAMv2 Simulations","authors":"N. Desai, M. Diao, Y. Shi, X. Liu","doi":"10.1029/2024JD041588","DOIUrl":"https://doi.org/10.1029/2024JD041588","url":null,"abstract":"Earth's high-latitude regions show a considerable amount of cloud coverage, which significantly affects global radiation budgets. In this study, we examine ground- and ship-based remote sensing observations from two Atmospheric Radiation Measurement (ARM) field campaigns conducted in the high-latitude regions of Northern and Southern Hemispheres (NH and SH). A comparison of macrophysical properties for low, mid-level, high, and deep clouds shows that the cloud top heights and thickness values are higher in the Arctic for each cloud type compared with the Southern Ocean and Antarctic regions, possibly due to higher sea surface temperatures in the north Atlantic. The Arctic also shows lower ice phase occurrence frequencies compared with the SH high latitudes for low clouds. For high, mid-level and deep clouds, the cloud phase distributions as a function of temperature show small geographical variabilities. The observations are then compared with the Department of Energy (DOE) Energy Exascale Earth System Model (E3SM) to evaluate the representations of these cloud properties. The results show that the model captures cloud base and top heights well and reproduces the differences in cloud macrophysical properties between the two hemispheres. But the model underestimates ice phase frequencies for all cloud types. Such model cloud phase bias is strongly correlated with positive relative humidity biases and negative aerosol number concentration biases, indicating an important role of relative humidity and aerosols in modulating cloud phase partitioning in the model.","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 8","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143866045","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

Resonant Asian Monsoon During Intermediate Conditions of the Last Deglaciation: Insights From Speleothem Records

IF 3.8 2区地球科学

Journal of Geophysical Research: Atmospheres Pub Date : 2025-04-23 DOI: 10.1029/2024JD042523

Jingyao Zhao, Carlos Pérez-Mejías, Xiyu Dong, Yassine Ait Brahim, Jiahui Cui, Liangkang Pan, Xi Chen, Kexin Wang, Yan Yang, Jun Cheng, Haiwei Zhang, Liangcheng Tan, Hai Cheng

{"title":"Resonant Asian Monsoon During Intermediate Conditions of the Last Deglaciation: Insights From Speleothem Records","authors":"Jingyao Zhao, Carlos Pérez-Mejías, Xiyu Dong, Yassine Ait Brahim, Jiahui Cui, Liangkang Pan, Xi Chen, Kexin Wang, Yan Yang, Jun Cheng, Haiwei Zhang, Liangcheng Tan, Hai Cheng","doi":"10.1029/2024JD042523","DOIUrl":"https://doi.org/10.1029/2024JD042523","url":null,"abstract":"Extensive research has explored how sweet spot conditions influence climate variability in the nonlinear Earth system. However, their effects throughout deglaciations remain unclear. Based on an annual-laminated speleothem δ18O record with unprecedented chronology precision, we first identified a two-step termination of the Asian Heinrich Period-1 at 15.11 and 14.69 ky BP (thousand years before present, where the present is 1950 CE), each marked by a centennial-scale strengthening of the Asian summer monsoon (ASM), in contrast to centennial-scale ASM weakening events observed at 17.8 and 16.09 ky BP. These transitions occurred under intermediate CO2 and ice volume conditions, which dynamically paced the Atlantic Meridional Overturning Circulation (AMOC) fluctuations and the subsequent reoccurrence of ASM events. It highlights the role of stochastic resonance in nonlinear climate system. Additionally, these AMOC/ASM events also resonated with abrupt CO2 risings across various pervasive modes of variability, which account for half of total CO2 rise during last deglaciation. This substantial contribution to CO2 increases played a key role in ice termination.","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 8","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143865856","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