Atmospheric Science Letters最新文献

{"title":"Increased Numerical Accuracy of Terrain Slope Amplifies Advection Errors in Idealized 2D Experiments Under Terrain-Following Coordinate","authors":"Qun Tian,&nbsp;Daosheng Xu,&nbsp;Zitong Chen","doi":"10.1002/asl2.70054","DOIUrl":"https://doi.org/10.1002/asl2.70054","url":null,"abstract":"<p>This study investigates the impact of numerical accuracy of terrain slope on advection errors under Gal-Chen and Somerville terrain-following coordinates. Through a series of idealized 2D linear advection experiments, we demonstrate that increasing the numerical accuracy of terrain slope (from second- to fourth-order) amplifies advection errors under steep topographic conditions, irrespective of the numerical accuracy of other spatial differences in the advection equation. Mechanistic analysis reveals that this error amplification is predominantly caused by the horizontal advection process, wherein higher-order accuracy terrain slope introduces intensified unresolved small-scale topographic forcings, which manifest as spurious waves through aliasing. These findings indicate that increased numerical accuracy does not invariably enhance model performance and highlight the need for careful attention to terrain representation in the model.</p>","PeriodicalId":50734,"journal":{"name":"Atmospheric Science Letters","volume":"27 7","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/asl2.70054","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148616006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Statistical Analysis of the Location Characteristics of the East Asian Trough Under the Remote Influence of Tropical Cyclones","authors":"Ruiqing Qi,&nbsp;Tianju Wang,&nbsp;Bowen Liu","doi":"10.1002/asl2.70057","DOIUrl":"https://doi.org/10.1002/asl2.70057","url":null,"abstract":"<p>Tropical cyclones (TCs) and the East Asian trough (EAT) are prominent circulation systems over the Western North Pacific (WNP)–East Asia region. Using statistical analysis, this study investigates the remote influences of TC activity over the tropical WNP on the location of the EAT and examines the possible underlying reasons. Results show that TC activity can cause the EAT line to move northwestward. The anomalous geopotential height induced by the remote influence of TC activity is a key factor in displacing the EAT, with the EAT line shifting away from regions with positive anomalous geopotential height. The anomalous warm advection and anomalous latent heat release induced by TC activity over the region east of the EAT line result in positive temperature anomalies, which further generate positive geopotential height anomalies under the constraint of static equilibrium, ultimately displacing the EAT. Findings of this study reveal the important modulating role of WNP TC activity on the East Asian mid-latitude climate system.</p>","PeriodicalId":50734,"journal":{"name":"Atmospheric Science Letters","volume":"27 7","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/asl2.70057","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148615958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Past Global Warming Influence on Intense Typhoons Reaching Southern China During El Niño and La Niña Using a Variable Resolution Global Model","authors":"Duofan Zheng,&nbsp;Shao-Yi Lee,&nbsp;Xian Zhu,&nbsp;Wenjie Dong","doi":"10.1002/asl2.70052","DOIUrl":"https://doi.org/10.1002/asl2.70052","url":null,"abstract":"<p>Four equilibrium climate simulations using the Community Earth System Model version 2.2 forced by prescribed Sea Surface Temperature (SST). The model mesh was regionally refined to 0.25° horizontally over the Asia-Pacific, in order to generate intense typhoons (maximum sustained winds above 41.5 m s⁻¹). Two baseline simulations were forced by SSTs of 1997 (El Niño), 2000 (La Niña). The global SST was detrended by removing Mode 1 from Empirical Orthogonal Function decomposition. Two more “non-warming” simulations of 1997 and 2000 were performed. Intense typhoon tracks were grouped with agglomerative hierarchical clustering and categorized into westward and curved tracks. Mode 1 decreased the number of westward tracks for 2000, while there were no statistically significant changes in curved tracks for 2000 and both types for 1997. Mode 1 also increased track density over the Luzon Strait toward Guangdong in 1997 (not significant), and over the Yangtze River mouth in 2000 (significant). It is therefore possible that the perceived increased typhoon damage in recent years may be due to intense typhoon tracks shifting to more populated and economically important regions. However, since only 2 years were analyzed, the track changes may be due to residual SST anomalies that were event-specific. Furthermore, there remained uncertainty in the individual effects of global warming and climate variability signals contained inside Mode 1.</p>","PeriodicalId":50734,"journal":{"name":"Atmospheric Science Letters","volume":"27 7","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/asl2.70052","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148343187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 Tropical Cyclogenesis in the Bay of Bengal Across the Phase Space of the Madden–Julian Oscillation","authors":"Bradford S. Barrett,&nbsp;Nadim Mahmud,&nbsp;Md Masud-Ul-Alam,&nbsp;Pallav Ray,&nbsp;Sahadat Habib,&nbsp;Md Foysal,&nbsp;Most Israt Jahan Mili,&nbsp;Md Hanif Biswas","doi":"10.1002/asl2.70051","DOIUrl":"https://doi.org/10.1002/asl2.70051","url":null,"abstract":"<p>In this study, probabilities of tropical cyclogenesis in the Bay of Bengal (BoB) were analyzed across the full two-dimensional phase space of the real-time multivariate Madden–Julian oscillation (MJO) (RMM) index for pre- and post-monsoon periods from 1990 to 2025. Results show that cyclogenesis anomalies span the phase space and depend largely on the sign of the first principal component of the index, RMM1. Moreover, on days when the intraseasonal index is in phases previously found favorable for cyclogenesis, the anomalies are statistically significant for only a limited range of amplitudes in those phases. Skill scores were calculated for vertical velocity (VV), relative humidity (RH), sea level pressure (SLP), vertical wind shear (VWS), and sea surface temperature (SST) to quantify how well each parameter identifies cyclogenesis in the intraseasonal phase space. Among these variables, 700-hPa VV was most skillful at identifying both pre- and post-monsoon cyclogenesis anomalies, outperforming RH, SLP, VWS, and SST, although all had high false alarm ratios. The 700-hPa VV was also more skillful than the 500-hPa VV, suggesting that it should be included in intraseasonal genesis indices. In the post-monsoon period, SST showed little to no skill at identifying intraseasonal cyclogenesis anomalies, in agreement with recent work suggesting it be considered alongside other modes of variability. The results of this study fill a critical gap in our understanding of the MJO–tropical cyclone relationship in the BoB by establishing basin-specific probabilities of cyclogenesis across multiple MJO states and identifying drivers of the variability.</p>","PeriodicalId":50734,"journal":{"name":"Atmospheric Science Letters","volume":"27 6","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/asl2.70051","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148282221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Three-Year Characterization of Boundary Layer Dynamics From GNSS Zenith Wet Delay Spectral Analysis","authors":"Gaël Kermarrec,&nbsp;Xavier Calbet,&nbsp;Zhiguo Deng","doi":"10.1002/asl2.70038","DOIUrl":"https://doi.org/10.1002/asl2.70038","url":null,"abstract":"&lt;p&gt;Continuous monitoring of boundary layer turbulence remains a challenge due to sparse conventional instrumentation. Here we suggest that spectral analysis of Global Navigation Satellite System (GNSS) zenith wet delay (ZWD) fluctuations yields physically meaningful diagnostics of boundary layer state. From 3 years of co-located GNSS and Doppler lidar observations (January 2022–December 2024, &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;N&lt;/mi&gt;\u0000 &lt;mo&gt;=&lt;/mo&gt;\u0000 &lt;mn&gt;52,608&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ N=mathrm{52,608} $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;) at Payerne, Switzerland, we extract the variance &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msup&gt;\u0000 &lt;mi&gt;σ&lt;/mi&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {sigma}^2 $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, a measure of integrated water vapor turbulence intensity, and the cutoff frequency &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;α&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ alpha $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, which marks the spectral extent of turbulent mixing. Annual harmonic analysis reveals that &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;α&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ alpha $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; captures 54% of its variance through the seasonal cycle (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msup&gt;\u0000 &lt;mi&gt;R&lt;/mi&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msup&gt;\u0000 &lt;mo&gt;=&lt;/mo&gt;\u0000 &lt;mn&gt;0.54&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {R}^2=0.54 $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, peak in January), while &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msup&gt;\u0000 &lt;mi&gt;σ&lt;/mi&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {sigma}^2 $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; peaks in August (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msup&gt;\u0000 &lt;mi&gt;R&lt;/mi&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msup&gt;\u0000 &lt;mo&gt;=&lt;/mo&gt;\u0000 &lt;mn&gt;0.21&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {R}^2=0.21 $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;). The inverse &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;α&lt;/mi&gt;\u0000 ","PeriodicalId":50734,"journal":{"name":"Atmospheric Science Letters","volume":"27 6","pages":""},"PeriodicalIF":2.0,"publicationDate":"2026-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/asl2.70038","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148174198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Observation Impact of Moored Buoys in the Eastern Tropical Indian Ocean During Boreal Winter Using Ensemble-Based Forecast Sensitivity to Observations","authors":"Miki Hattori,&nbsp;Akira Yamazaki,&nbsp;Iwao Ueki","doi":"10.1002/asl2.70037","DOIUrl":"https://doi.org/10.1002/asl2.70037","url":null,"abstract":"<p>Understanding the impact of marine meteorological observations is crucial for improving atmospheric analyzes, particularly in data-sparse oceanic regions. This study investigated the impact of marine meteorological observations on atmospheric forecasts over the eastern tropical Indian Ocean, using the Ensemble-based Forecast Sensitivity to Observations (EFSO) technique. 17-year statistics revealed pronounced seasonality; impacts were significantly greater during boreal winter than in summer, despite comparable observation frequencies. Focusing on moored buoys, the results showed a strong correspondence between observation impacts and the intensity of atmospheric disturbances. High impacts were spatially aligned with eastward-propagating moist convective disturbances such as the Madden–Julian Oscillation (MJO). The impact of the buoys near 95°E increased across a broad area associated with MJO passage. Even behind the MJO-active phase, enhanced impacts were detected from small-scale moist convective disturbances, though their spatial influence was more limited. Observation type comparison revealed that near 95°E, the impact of surface marine observations increased markedly with convective activity, accompanied by enhanced satellite-derived impacts. Moist energy accounted for the largest share of the total observation impacts, followed by kinetic energy, highlighting the role of near-surface marine observations in improving the representation of low-level moisture and wind structures essential for the development of moist atmospheric disturbances.</p>","PeriodicalId":50734,"journal":{"name":"Atmospheric Science Letters","volume":"27 6","pages":""},"PeriodicalIF":2.0,"publicationDate":"2026-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/asl2.70037","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148173809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Interdecadal Change in Summer Extreme Rainfall Over North China Around the Early 2000s: Drivers and Mechanisms","authors":"Shiya Deng,&nbsp;Hongbo Liu,&nbsp;Xuechao Feng,&nbsp;Yong Wang","doi":"10.1002/asl2.70050","DOIUrl":"https://doi.org/10.1002/asl2.70050","url":null,"abstract":"<p>Recent increases in summer extreme rainfall over North China pose growing societal risks, yet their long-term evolution and governing mechanisms remain poorly understood. Systematic analysis of observations from 1979 to 2021 reveals a discernible interdecadal change in extreme rainfall around the early 2000s, transitioning to a wetter period characterized by increased mean values and accelerated trends. Unlike the late-1970s interdecadal change of rainfall, this recent increase of extreme rainfall occurred alongside a weakened East Asia summer monsoon, implying distinct drivers. Acting alongside global warming, two key internal variability mechanisms amplify the rise in extreme rainfall: (1) phase reversals of the Pacific Decadal Oscillation (negative) and Atlantic Multidecadal Oscillation (positive) established an upper-level divergent and lower-level convergent anomaly, sustaining ascent over North China via a poleward-shifted East Asian westerly jet and adjusted associated secondary circulation; and (2) Indian Ocean warming drove the western Pacific subtropical high to strengthen, extend westward, and shift northward, intensifying southeasterly moisture transport. Together, these oceanic forcings set favorable dynamic and thermodynamic conditions for increased extremes.</p>","PeriodicalId":50734,"journal":{"name":"Atmospheric Science Letters","volume":"27 6","pages":""},"PeriodicalIF":2.0,"publicationDate":"2026-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/asl2.70050","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148173823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Possible Mechanism for the Record-Breaking Cold Event Over Northeastern China in December 2023: Role of Extreme Negative North Atlantic Oscillation","authors":"Yi Yuan,&nbsp;Jianqi Sun,&nbsp;Zixuan Zeng,&nbsp;Yixi Liu,&nbsp;Shui Yu","doi":"10.1002/asl2.70039","DOIUrl":"https://doi.org/10.1002/asl2.70039","url":null,"abstract":"<p>In early winter of 2023 (December 9th–23rd), a record-breaking cold event hits northeastern China (NEC), resulting in serious economic losses and significant disruptions to daily life. Our analysis suggests that this cold event is attributed to the preceding extreme negative phase of the North Atlantic Oscillation (NAO). The NAO-related Barents–Kara Seas high (BKH) leads to the southward invasion of polar cold air into Siberia. The accumulation of cold air favors the enhancement of the Siberian high. In addition, at the upper level, the BKH induces upper-level convergence and downward motion over Siberia. The accumulated cold air and downward motion jointly favor the development and maintenance of the historically strongest Siberian high in December 2023. Accordingly, the strong northerly winds associated with the strongest Siberian high transport cold air southward to NEC, resulting in the record-breaking cold event over the region in December 2023.</p>","PeriodicalId":50734,"journal":{"name":"Atmospheric Science Letters","volume":"27 6","pages":""},"PeriodicalIF":2.0,"publicationDate":"2026-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/asl2.70039","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148167141","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"","authors":"","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":50734,"journal":{"name":"Atmospheric Science Letters","volume":"27 6","pages":""},"PeriodicalIF":2.0,"publicationDate":"2026-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148097498","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"","authors":"","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":50734,"journal":{"name":"Atmospheric Science Letters","volume":"27 6","pages":""},"PeriodicalIF":2.0,"publicationDate":"2026-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148097500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}