Geophysical Research Letters最新文献

{"title":"Internal Wind Driven Ocean Circulation Variability Delays the Time of Emergence of Externally Forced Sea Surface Temperature Trends","authors":"Sarah M. Larson,&nbsp;Kay McMonigal","doi":"10.1029/2024GL111878","DOIUrl":"https://doi.org/10.1029/2024GL111878","url":null,"abstract":"<p>In parts of the global ocean, large internal variability continues to mask the detection of externally forced sea surface temperature (SST) trends in observations and climate models. Such regions of large internal variability are typically where wind driven ocean dynamical processes contribute heavily to SST variability. Through analysis of two climate model ensembles, we find that internal wind driven ocean circulation variability delays the time of emergence of SST signals nearly everywhere, but the delay is longest (&gt;10 years) in dynamically active regions like the tropical oceans. We also find that internal wind driven ocean circulation variability is the dominant contributor to changes in the amplitude of internal SST variability over the historical period. Results suggest that inter-model differences in wind driven SST variability may be a key contributor to inter-model differences in the time of emergence of externally forced SST signals in climate change scenarios.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 7","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GL111878","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143801655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"A Practical Probabilistic Benchmark for AI Weather Models","authors":"Noah D. Brenowitz,&nbsp;Yair Cohen,&nbsp;Jaideep Pathak,&nbsp;Ankur Mahesh,&nbsp;Boris Bonev,&nbsp;Thorsten Kurth,&nbsp;Dale R. Durran,&nbsp;Peter Harrington,&nbsp;Michael S. Pritchard","doi":"10.1029/2024GL113656","DOIUrl":"https://doi.org/10.1029/2024GL113656","url":null,"abstract":"<p>Since the weather is chaotic, it is necessary to forecast an ensemble of future states. Recently, multiple AI weather models have emerged claiming breakthroughs in deterministic skill. Unfortunately, it is hard to fairly compare ensembles of AI forecasts because variations in ensembling methodology become confounding and the baseline data volume is immense. We address this by scoring lagged initial condition ensembles—whereby an ensemble can be constructed from a library of deterministic hindcasts. This allows the first parameter-free intercomparison of leading AI weather models' probabilistic skill against an operational baseline. Lagged ensembles of the two leading AI weather models, GraphCast and Pangu, perform similarly even though the former outperforms the latter in deterministic scoring. These results are elaborated upon by sensitivity tests showing that commonly used multiple time-step loss functions damage ensemble calibration.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 7","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GL113656","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143793702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Speed of Interplanetary Shocks Through the Magnetosheath: A Toy Model","authors":"C. Moissard,&nbsp;C. Butcher,&nbsp;E. Ruler,&nbsp;J. Richardson,&nbsp;B. Michotte de Welle,&nbsp;W. Steward,&nbsp;M. Pritchard,&nbsp;D. Gonzalez Del Valle,&nbsp;V. Defayet,&nbsp;A. Bernal,&nbsp;V. Cavicchi,&nbsp;V. David","doi":"10.1029/2024GL113488","DOIUrl":"https://doi.org/10.1029/2024GL113488","url":null,"abstract":"<p>Before interacting with the magnetosphere, an interplanetary shock travels through the magnetosheath where its speed and shape are modified. Previous studies have reported widely different answers to the question of the speed of an interplanetary shock in the magnetosheath. Observational studies generally answer this question “macroscopically”, by measuring the time delay between detections of the interplanetary shock at two or more locations and inferring its average speed. In this letter, we instead propose a local predictive model for the velocity and show that paradoxical results from previous authors arise naturally from their use of different detection methods. Our model can be used to predict the propagation of an interplanetary shock in the magnetosheath with a simple laptop, yet provides results which are in broad agreement with much heavier magnetohydrodynamics and hybrid particle-in-cell simulations.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 7","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GL113488","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143793699","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Variability of Autumn Tropical Pacific Yellowfin Tuna Tied to the Spring North Atlantic Tripole","authors":"Gongjun Zhang,&nbsp;Jianping Li","doi":"10.1029/2024GL114459","DOIUrl":"https://doi.org/10.1029/2024GL114459","url":null,"abstract":"<p>Climate change affects the spatial distribution and abundance of yellowfin tuna (<i>Thunnus albacares</i>, YFT) in the tropical Pacific, yet the mechanisms linking remote climate modes to YFT dynamics remain unclear. This study finds that the variability of autumn tropical Pacific YFT is tied to the spring sea surface temperature anomalies (SSTAs) of the North Atlantic Tripole (NAT), mediated by the Victoria Mode (VM), the second dominant mode of North Pacific SSTAs variability. The result shows that the spring NAT is significantly positive correlated with the subsequent autumn tropical Pacific YFT catch per unit effort (CPUE). The spring NAT triggers eastward-propagating Rossby waves, inducing VM-like SSTAs in the North Pacific. These anomalies modify YFT habitat conditions in the tropical Pacific through coupled oceanic-atmospheric bridge (COAB) mechanism, ultimately affecting autumn CPUE. This study unveils a teleconnection-driven mechanism influencing tropical Pacific YFT CPUE, with important implications for fisheries management and forecasting.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 7","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GL114459","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143793703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"A Positive Indian Ocean Dipole Leads to an Indian Ocean Basin Mode that Favors the Development of La Niña the Following Year","authors":"Jing Wang,&nbsp;Shouwen Zhang,&nbsp;Yuanlong Li,&nbsp;Janet Sprintall","doi":"10.1029/2024GL112632","DOIUrl":"https://doi.org/10.1029/2024GL112632","url":null,"abstract":"<p>Interactions among the El Niño-Southern Oscillation, Indian Ocean Basin mode (IOB), and Indian Ocean Dipole (IOD) significantly impact global climate variability and seasonal predictions. Traditionally, positive IOD (pIOD) and IOB warming events are associated with El Niño, driven by its influence on the tropical Indian Ocean through Walker Circulation anomalies. Our findings enrich this framework, revealing that a pIOD without El Niño can independently trigger IOB warming, and both types of pIODs can induce La Niña events. While El Niño primarily forces IOB warming and subsequent La Niña development via the atmospheric bridge across the Maritime Continent, pIODs independent of El Niño influence IOB warming through oceanic dynamics, which further favors La Niña development in the following year. The NMEFC-CESM model sensitivity experiments underscore the critical role of thermocline processes in this mechanism, dependent on the pIOD's temperature amplitude, offering vital insights for forecasting post-IOD, IOB, and La Niña events.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 7","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GL112632","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143793701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Parameterizing the Heterogeneous Liquid-Ice Mixing in Modeling Ice Growth Through the Wegener-Bergeron-Findeisen Process in CAM6","authors":"Jing Yang,&nbsp;Jianqiao Lu,&nbsp;Yuting Deng,&nbsp;Yong Wang,&nbsp;Chunsong Lu,&nbsp;Yan Yin,&nbsp;Zhien Wang,&nbsp;Xiaoqin Jing,&nbsp;Kang Yang","doi":"10.1029/2024GL114036","DOIUrl":"https://doi.org/10.1029/2024GL114036","url":null,"abstract":"<p>Accurate representation of cloud phase partitioning is critical for understanding the cloud feedback to climate change, but the supercooled liquid fraction is often underestimated in global climate models, in part due to the assumption of homogeneous distributions of hydrometeors in mixed-phase clouds. In this study, we take into account the heterogeneous liquid-ice mixing in modeling the ice depositional growth using airborne in situ measurements. The impact of heterogeneous liquid-ice mixing on the Wegener-Bergeron-Findeisen process is parameterized as the fraction of ice that is mixed with liquid water, which is a function of liquid-ice mixing homogeneity and liquid fraction. The liquid-ice mixing homogeneity, quantified using the information entropy theory, is parameterized using the total condensed water content and temperature. With this observationally constrained parameterization incorporated in the Community Atmospheric Model version 6, the modeled cloud phase partitioning and cloud radiative forcing are improved.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 7","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GL114036","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143793578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Response of Australian Summer Monsoon Precipitation to a Strengthening Antarctic Circumpolar Current","authors":"Yuhui Han,&nbsp;Song Yang,&nbsp;Peixi Wang,&nbsp;Zhenning Li,&nbsp;Xiaoming Hu","doi":"10.1029/2024GL113080","DOIUrl":"https://doi.org/10.1029/2024GL113080","url":null,"abstract":"<p>The Australian summer monsoon (AUSM) is the strongest monsoon in the Southern Hemisphere and it is greatly influenced by the climate conditions in the Indo-Pacific and adjacent regions. Inspite of the substantial studies of the monsoon, the linkage between the AUSM and the high-latitude Southern Ocean climate has not been fully understood. This study investigates how AUSM rainfall is affected by the Antarctic Circumpolar Current (ACC) by simulating scenarios with a closed and an opened Drake Passage with the Community Earth System Model. It is found that AUSM precipitation decreases as a result of reduced local humidity caused by a strengthening ACC. An opened Drake Passage leads to strengthening ACC and Atlantic Meridional Overturning Circulation, which in turn creates an El Niño-like state in the Pacific. This weakens the Walker Circulation, resulting in reduced local moisture, anomalous subsidence over the AUSM region, and a subsequent decrease in monsoon precipitation.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 7","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GL113080","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143793700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Impacts of Continuous Water Diversions by the South-To-North Water Diversion Project on Increased Precipitation and Decreased Temperature in Water-Receiving Areas","authors":"Haodong Deng,&nbsp;Qingming Wang,&nbsp;Yong Zhao,&nbsp;Yongnan Zhu,&nbsp;Shan Jiang,&nbsp;Jiaqi Zhai,&nbsp;Yunpeng Gui,&nbsp;Xiaoxue Chen,&nbsp;Lichuan Wang,&nbsp;Kuan Liu","doi":"10.1029/2024GL113549","DOIUrl":"https://doi.org/10.1029/2024GL113549","url":null,"abstract":"<p>Climate impacts of the South-to-North water diversion project in China on water-receiving areas (WRA) is simulated by the Weather Research and Forecasting (WRF) model. The results show that during the 2015–2022 water diversion period, the WRA experiences increased precipitation and decreased temperature. Annual precipitation increased by 2.8 mm, mainly dominated by non-convective precipitation (1.92 mm). Although the upwind region receives more water, the increase in water vapor flux is more dramatic in the downwind region due to the spring northwest monsoon; The decreased temperature effect is most pronounced in spring (over 0.15°C), and over 10 mm of evaporation increase in the downwind region. The sensible heat flux decrease is less pronounced than the latent heat flux increase, mainly because of the insulating effect, which prevented evaporative cooling reduction. This study advances our understanding of the mechanisms by which large-scale water diversion affects WRA climates.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 7","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GL113549","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143786874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Optimized J2 Recovery for Multi-Decadal Geophysical Studies","authors":"B. D. Loomis,&nbsp;T. J. Sabaka,&nbsp;K. E. Rachlin,&nbsp;M. J. Croteau,&nbsp;F. G. Lemoine,&nbsp;R. S. Nerem,&nbsp;A. Bellas-Manley","doi":"10.1029/2024GL114472","DOIUrl":"https://doi.org/10.1029/2024GL114472","url":null,"abstract":"<p>The time history of the Earth's dynamic oblateness, or <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>J</mi>\u0000 <mn>2</mn>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${J}_{2}$</annotation>\u0000 </semantics></math>, is a unique climate data record, with its estimation from satellite laser ranging (SLR) tracking data beginning in 1976. Due to its impact on variations in length of day (LOD), the long-term <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>J</mi>\u0000 <mn>2</mn>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${J}_{2}$</annotation>\u0000 </semantics></math> time series is frequently applied to LOD studies and their contributions, which include tidal friction, glacial isostatic adjustment, ice melt, sea level change, and the angular momentum exchange between the fluid outer core and the mantle. Previous studies demonstrated that the accurate recovery of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>J</mi>\u0000 <mn>2</mn>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${J}_{2}$</annotation>\u0000 </semantics></math> requires the use of time variable gravity models from GRACE when processing the SLR tracking data. However, no reliable models exist prior to GRACE's 2002 launch, calling into to question the accuracy and utility of the pre-GRACE estimates. Here we present a new approach to accurately recover <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>J</mi>\u0000 <mn>2</mn>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${J}_{2}$</annotation>\u0000 </semantics></math> without gravity modeling, resulting in the first fully consistent long-term solution for climate studies.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 7","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GL114472","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143793654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"An Observation of the Trapped Lee Waves Using Fengyun-4 Satellite Images and a U-Net Network","authors":"Ao Xu,&nbsp;Haile Xue,&nbsp;Ronghua Wu,&nbsp;Qiying Chen","doi":"10.1029/2024GL113858","DOIUrl":"https://doi.org/10.1029/2024GL113858","url":null,"abstract":"<p>Propagating in the lower troposphere, the trapped lee waves (TLWs) generate severe turbulence over a large area in the afternoon and thus have a significant impact on aviation safety and atmospheric environment. Due to the lack of high temporal and spatial resolution observations, the diurnal variation of the TLWs remains unknown. This study employed the U-Net deep learning model to identify 3,533 images with TLWs from over thirty thousand 500-m resolution Fengyun-4 satellite images at intervals of a few minutes during the cold season from 2020 to 2023. The results show that the wavelength increases in the afternoon (from 12:00 to 16:00 LST) with high low-level winds and low atmospheric stability while the amplitude and propagation area continually increase during the daytime (from 09:00 to 16:00 LST) as the boundary layer becomes turbulent. These findings explain environmental disasters related to severe turbulence in the afternoon over the mountainous region.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 7","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GL113858","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143786875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}