Journal of Geophysical Research: Atmospheres最新文献

{"title":"Preliminary Breakdown Process of Winter Positive Cloud-To-Ground Lightning and Its Relation to the Following First Return Stroke","authors":"Qingliu Yang,&nbsp;Daohong Wang,&nbsp;Ting Wu","doi":"10.1029/2024JD041496","DOIUrl":"https://doi.org/10.1029/2024JD041496","url":null,"abstract":"<p>We have studied the preliminary breakdown (PB) process and its relation to the following positive first return stroke (RS) for 60 winter positive cloud-to-ground (+CG) lightning flashes using their 3D mapping data by Discone Antenna Lightning Mapping Array in conjunction with the E-field change information by Fast Antenna Lightning Mapping Array. 31 (52%) PBs are found to propagate upward, 27 (45%) downward, and the remaining 2 (3%) with some initial progression direction reversal features. The winter +CG PBs can be characterized with an initiation height from 0.9 to 4.4 km, a propagation distance from 0.2 to 2.6 km, a propagation speed from <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>3</mn>\u0000 <mo>.</mo>\u0000 <mn>5</mn>\u0000 <mo>×</mo>\u0000 <msup>\u0000 <mn>10</mn>\u0000 <mn>5</mn>\u0000 </msup>\u0000 </mrow>\u0000 <annotation> $3.5times {10}^{5}$</annotation>\u0000 </semantics></math> to <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>5.4</mn>\u0000 <mo>×</mo>\u0000 <msup>\u0000 <mn>10</mn>\u0000 <mn>6</mn>\u0000 </msup>\u0000 </mrow>\u0000 <annotation> $5.4times {10}^{6}$</annotation>\u0000 </semantics></math> m/s without significant differences between upward and downward PBs. The time interval and the 2D displacement distance from the PB initiation to the first RS range from 6.1 to 603.7 ms, from 0 to 39.2 km, respectively. Return strokes with strongest intensities tend to have shorter intervals and 2D displacements between PB and RS. We also found some weak correlations between the PB characteristic parameters. All 60 +CGs involved multiple charge regions with opposite polarities and small separations. Finally, we have discussed our findings.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 8","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD041496","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143850971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Summertime Carbonaceous Aerosol in Interior Versus Coastal Northern Alaska","authors":"Allison M. Welch,&nbsp;Tate Matthews,&nbsp;Rebecca J. Sheesley,&nbsp;Hui Wang,&nbsp;Kelley C. Barsanti,&nbsp;Nicole Nielsen,&nbsp;Xiaomei Xu,&nbsp;Lurui Niu,&nbsp;Alex B. Guenther,&nbsp;Claudia I. Czimczik","doi":"10.1029/2024JD042080","DOIUrl":"https://doi.org/10.1029/2024JD042080","url":null,"abstract":"<p>Rapid warming is likely increasing primary production and wildfire occurrence in the Arctic. Projected changes in carbonaceous aerosols during the summer will impact atmospheric chemistry and climate, but our understanding of these processes is limited by sparse observations. Here, we characterize carbonaceous aerosol in Alaska, USA: Toolik Field Station in the Interior and the Atmospheric Radiation Measurement facility at Utqiaġvik on the Arctic coast, during the summers of 2022 and 2023. We estimated PM_2.5 and PM₁₀ concentrations using laser light scattering (PurpleAir sensors) and examined total carbon (TC) and its organic carbon (OC) and elemental carbon (EC) fractions in total suspended particles (TSP). We investigated the dominant sources of carbonaceous aerosol using air mass backward-trajectories from the NOAA HYSPLIT model and radiocarbon source apportionment of TC. TC concentrations were about twice as high in the Interior compared to the coast, with contemporary sources dominating at both Toolik (95%–99%) and Utqiaġvik (86%–89%) over minor contributions from fossil sources. Elevated PM, TC, OC, and EC concentrations coincided with major boreal forest fire activity in North America that brought smoke to the region. The radiocarbon signature of EC measured at Toolik during these wildfire events indicated that over 90% of the EC came from contemporary sources. Our measurements demonstrate the potential for Arctic aerosol concentrations to respond significantly to climate warming-induced changes to the landscape and emphasize the need for continuous atmospheric monitoring to advance our understanding of this rapidly changing environment.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 8","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD042080","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143850980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Atmospheric HONO Observed Over Global Biomass Burning Regions Using Satellite Observations of TROPOMI and GEMS","authors":"N. Theys,&nbsp;H. Yu,&nbsp;B. Franco,&nbsp;L. Clarisse,&nbsp;R. Volkamer,&nbsp;H. Cha,&nbsp;J. Kim,&nbsp;I. De Smedt,&nbsp;T. Stavrakou,&nbsp;J. van Gent,&nbsp;M. Van Roozendael","doi":"10.1029/2024JD043163","DOIUrl":"https://doi.org/10.1029/2024JD043163","url":null,"abstract":"<p>Nitrous acid (HONO) is a key tropospheric species primarily due to ist role as a source of the hydroxyl radical (OH), which is pivotal in breaking down pollutants and greenhouse gases and is also a key ingredient to photochemical air pollution. Recent HONO measurements from space in fresh biomass burning plumes offer the potential to inform about HONO formation mechanisms globally. However, research is needed to further develop, interpret, and evaluate the satellite retrievals. Here, we present a new global HONO column data set of 5.5 years from the TROPOspheric Monitoring Instrument (TROPOMI). We leverage the Covariance-Based Retrieval Algorithm to significantly improve the sensitivity to weak HONO signals over all biomass burning regions. Radiative transfer simulations for retrieving HONO columns indicate a strong dependence on plume height and smoke aerosols. Such information is mostly inaccessible from space for thick plumes but can be obtained from suborbital measurements during dedicated campaigns. We compare the TROPOMI HONO columns to aircraft observations from the BB-FLUX campaign. When explicitly accounting for aerosols, the satellite and aircraft data are in good agreement albeit with significant comparison uncertainty. We also evaluate the TROPOMI retrievals against HONO columns measured by IASI and discuss the differences. Next, we demonstrate the potential of geostationary satellites like the Geostationary Environment Monitoring Spectrometer to provide temporally resolved information on pyrogenic HONO. Finally, we find a close relationship between satellite HONO detections and fire intensity both in space and time, highlighting the likely dominance of HONO production during the flaming phase of the fires.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 8","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143850981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Marine Boundary Layer Cloud Condensation Nuclei Bias Over the Southern Ocean: Comparisons Between the Community Atmosphere Model 6 and Field Observations","authors":"Qing Niu,&nbsp;Christina McCluskey,&nbsp;Greg M. McFarquhar","doi":"10.1029/2024JD042734","DOIUrl":"https://doi.org/10.1029/2024JD042734","url":null,"abstract":"<p>Marine boundary layer (MBL) clouds play a crucial role in regulating radiative balance in the atmosphere. Previous studies identified that MBL cloud droplet number concentration (Nd) is underestimated by a factor of 2 over the summertime Southern Ocean (SO) close to the Antarctic coast in many models. Here, comparisons between cloud condensation nuclei (CCN) observations from field campaigns during the 2017–2018 Austral summer over the Australasian sector of the SO and simulated CCN from the Community Atmospheric Model 6 (CAM6) are presented. Modeled MBL CCN number concentration (N_CCN) is underestimated, by close to 100% at latitudes south of 55°S with the N_CCN bias (a) largest close to the Antarctic Plateau during summer, implying the biased CCN type has seasonal and latitudinal variation and, (b) three times larger over sea ice than over open water, implying sea spray CCN are better simulated compared to secondary CCN. Assessments of aerosol size distributions indicate an underestimation of accumulation-mode-aerosols (Ac) with diameters 70 nm &lt; D &lt; 100 nm. CCN supersaturation spectra indicate that the observed CCN had lower hygroscopicity compared to simulated CCN, implying differences in CCN chemical composition. With secondary aerosols including sulfate being less hygroscopic than sea salt CCN, the CCN activation ratio derived using bulk hygroscopicity kappa in the Abdul-Razzak function leads to an underestimation of critical supersaturation south of 62°S. The biases reported here highlight important shortfalls in simulated CCN that can be important to the well-documented underestimated <i>N</i>_d by Earth System Models, a key feature and uncertainty of pre-industrial conditions.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 8","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143850983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unraveling Ice Nucleating Particle Concentration Variability: Insights Into Source Emissions Origin and Parameterizations","authors":"A. Canzi,&nbsp;E. Freney,&nbsp;P. Grzegorczyk,&nbsp;J. L. Baray,&nbsp;L. Lacher,&nbsp;C. Planche","doi":"10.1029/2024JD041258","DOIUrl":"https://doi.org/10.1029/2024JD041258","url":null,"abstract":"<p>Despite having very low atmospheric concentrations, ice-nucleating particles (INPs) play an important role in the formation of atmospheric ice crystals at temperatures warmer than −35°C and hence in the atmospheric precipitation cycle. Moreover, they tend to have a very high spatiotemporal variability. In order to understand this variability, long-term measurements with high temporal resolution are essential. This paper presents an analysis of 3 months of online INP measurements (10 min time-resolved), using a PINE cloud chamber (−33°C ≤ T ≤ −22°C). Measurements were made from December 2022 to March 2023 at the PUY station (France, 1,465 m a.s.l), a site exposed to a variety of air masses including free troposphere conditions. A large part of the temporal variability of INP concentrations (over four orders of magnitude at a single temperature) can be explained by air mass origin. INP concentrations measured for oceanic air masses are in the lower range (from ≈0.1 to ≈10 L⁻¹). Those for continental air masses are in a medium range (from ≈1 to ≈100 L⁻¹) and depend on the level of pollution of the air mass. INP concentrations measured for southern air masses show highest concentrations (from ≈10 to ≈500 L⁻¹) and mostly depend on the amount of dust in the ambient air. Moreover, measurements were conducted during two dust events revealing INP concentrations over 1000 L⁻¹ at −32°C. Subsequently, a set of parameterizations capable of tracing the measured INP variability were developed. This will facilitate our understanding of the impact of INP concentrations on mixed-phase cloud properties with cloud models.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 8","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD041258","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143849299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Two-Day Wave Modulation of Gravity Wave Momentum Fluxes Observed Over South America","authors":"Ruth S. Lieberman,&nbsp;Gunter Stober,&nbsp;Erich Becker,&nbsp;Diego Janches,&nbsp;Jun Ma,&nbsp;Alan Liu","doi":"10.1029/2024JD042788","DOIUrl":"https://doi.org/10.1029/2024JD042788","url":null,"abstract":"<p>Planetary wave (PW) modulation of gravity wave (GW) dissipation has long been proposed as a source of longitudinal variability in the mesosphere and lower thermosphere. However, direct measurements of GW drag are rare. We identify 2-day wave variations in GW momentum fluxes measured by the Southern Argentina Agile Meteor Radar (SAAMER) in Rio Grande, Tierra del Fuego, and a meteor radar at the Andes Lidar Observatory (ALO) in Cerro Pachon, Chile. Typical amplitudes range from 1 to 5 <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msup>\u0000 <mi>m</mi>\u0000 <mn>2</mn>\u0000 </msup>\u0000 <msup>\u0000 <mi>s</mi>\u0000 <mrow>\u0000 <mo>−</mo>\u0000 <mn>2</mn>\u0000 </mrow>\u0000 </msup>\u0000 </mrow>\u0000 <annotation> ${mathrm{m}}^{2}{mathrm{s}}^{-2}$</annotation>\u0000 </semantics></math> and are generally, though not always, out of phase with the horizontal wind consistent with wind-induced dissipation of upward-propagating GWs. The 2-day wave-modulated GW drag ranges between 20 and 140 m <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msup>\u0000 <mi>s</mi>\u0000 <mrow>\u0000 <mo>−</mo>\u0000 <mn>1</mn>\u0000 </mrow>\u0000 </msup>\u0000 <mspace></mspace>\u0000 <msup>\u0000 <mtext>day</mtext>\u0000 <mrow>\u0000 <mo>−</mo>\u0000 <mn>1</mn>\u0000 </mrow>\u0000 </msup>\u0000 </mrow>\u0000 <annotation> ${mathrm{s}}^{-1} {text{day}}^{-1}$</annotation>\u0000 </semantics></math> and can amplify, damp, and alter the phase of the 2-day wave. These multiple relationships between the GW drag and the 2-day wave suggest that in situ processes may influence GW drag, including secondary GWs excited from the breakdown of primary GW packets.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 8","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD042788","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143845961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Interpreting Turbulence Anisotropy in a Streamline Coordinate System","authors":"Federica Gucci,&nbsp;Samuele Mosso,&nbsp;Nikki Vercauteren,&nbsp;Ivana Stiperski","doi":"10.1029/2024JD042212","DOIUrl":"https://doi.org/10.1029/2024JD042212","url":null,"abstract":"<p>Mixing and transport in the atmospheric boundary layer are a result of the anisotropic nature of turbulence. Recently the inclusion of anisotropy of the Reynolds stress tensor into similarity theory of near-surface turbulence has been proposed. Anisotropy is quantified through the eigenvalues of the anisotropy tensor, which can be visualized by geometric shapes. We conduct a systematic investigation of velocity variances and covariances conditional to this geometric shape with the purpose of identifying common patterns. We discuss the influence of eigenvectors' directions on turbulent transport in relation to the streamline coordinates defined along the mean wind vector. Eigenvectors' direction identifies the orientation of anisotropic shapes, and this geometric approach is meant to investigate if physical constraints on orientation exist, as these could inform turbulence parameterizations. Two data sets are used for the analyses, one from a relatively flat terrain and one from a glacier site. Results show that it is not possible to identify a unique orientation for each anisotropy. Geometric shapes span a broad range of inclinations in the vertical, not strongly constrained by height or atmospheric stability. However, anisotropic turbulence is shown to have shallower inclination than isotropic turbulence. One-component states, ubiquitous under stable stratification, are well described by the orientation of the dominant eigenvector in the horizontal, characterized by large horizontal covariance, or large variance which aligns anisotropy in the streamwise/spanwise direction. Results highlight that the geometric orientation of turbulence may depend on the site and future investigations will include geometric parameters characterizing the orography in the analyses.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 8","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD042212","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143849298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quaternary Nucleation of Iodine and Sulfur Oxoacids in the Marine Atmosphere: Unexpected Role of Methanesulfonic Acid","authors":"Rongjie Zhang,&nbsp;Hong-Bin Xie,&nbsp;Fangfang Ma,&nbsp;Rujing Yin,&nbsp;Jingwen Chen,&nbsp;Xu-Cheng He","doi":"10.1029/2024JD042220","DOIUrl":"https://doi.org/10.1029/2024JD042220","url":null,"abstract":"<p>Sulfuric acid (SA), methanesulfonic acid (MSA), iodic acid (HIO₃), and iodous acid (HIO₂) are identified as key nucleation precursors and can coexist in the marine atmosphere. Here, we investigated the potential SA-MSA-HIO₃-HIO₂ quaternary nucleation mechanism by exploring the formation of (SA)_<i>w</i>(MSA)_<i>x</i>(HIO₃)_<i>y</i>(HIO₂)_<i>z</i> (0 ≤ <i>w</i> + <i>x</i> + <i>y</i> ≤ 3, 1 ≤ <i>z</i> ≤ 3) clusters with quantum chemical calculation and kinetics modelling. The results indicate that SA-MSA-HIO₃-HIO₂ can effectively nucleate under marine atmospheric conditions. The nucleation rate is up to 7 orders of magnitude higher than that of SA/MSA-HIO₃-HIO₂, SA-MSA-HIO₂ ternary mechanisms, and SA/MSA/HIO₃-HIO₂ binary mechanisms at some specific conditions. The nucleation is mainly driven by acid-base reaction (HIO₂ as base) and halogen bonds besides hydrogen bonds, with the three acids showing both competitive and cooperative roles. More importantly, it was found that the contribution of MSA to the aerosol nucleation is comparable to SA at equal concentrations. The unexpectedly high contribution of MSA is attributed to its higher halogen-bonding capacity than SA. This study highlights the need to consider the multicomponent nucleation mechanism in the marine atmosphere for accurate aerosol and climate projections, and may serve as important proof that MSA as weak acid can effectively nucleate even coexisting with SA.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 8","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143840759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assimilating Precipitation Data via Full-Hydrometeor Scheme in WRF 4D-Var for Convective Precipitation Forecast Associated With the Northeast China Cold Vortex (NCCV)","authors":"Sen Yang,&nbsp;Deqin Li,&nbsp;Yunxia Duan,&nbsp;Yongshen Chen,&nbsp;Zhiquan Liu,&nbsp;Xiang-Yu Huang","doi":"10.1029/2024JD042427","DOIUrl":"https://doi.org/10.1029/2024JD042427","url":null,"abstract":"<p>The full-hydrometeor four-dimensional variational (4D-Var) assimilation scheme in the Weather Research and Forecasting (WRF) model, based on the WRF single-moment 6-class microphysics scheme (WSM6), is utilized to assimilate precipitation data. The focus is on short-term convective precipitation forecasts influenced by the Northeast China cold vortex (NCCV). Four assimilation experiments were designed to compare the warm rain scheme with the full-hydrometeor scheme, as well as to examine the differences between assimilating hourly surface rain gauge data and multi-source integrated precipitation products. Nine cases of intense convective precipitation related to NCCV were analyzed. The results demonstrate that the initial analysis of ice-phase hydrometeors was satisfactory across the three experiments utilizing the full-hydrometeor 4D-Var assimilation scheme. The assimilation of precipitation data using the full-hydrometeor scheme in WRF 4D-Var effectively adjusted atmospheric thermodynamic properties and decreased model spin-up time, leading to improved precipitation forecasts, especially for the 0–3 hr period. Furthermore, the assimilation of rain gauge data or multi-source integrated precipitation data has been demonstrated to be an effective approach for enhancing the accuracy of weather forecasts.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 8","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143840734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Regimes-Based Approach to Identifying Seasonal State-Dependent Prediction Skill","authors":"Kyle Shackelford,&nbsp;Charlotte A. DeMott,&nbsp;Peter Jan van Leeuwen,&nbsp;Elizabeth A. Barnes","doi":"10.1029/2024JD042917","DOIUrl":"https://doi.org/10.1029/2024JD042917","url":null,"abstract":"<p>Subseasonal-to-decadal atmospheric prediction skill attained from initial conditions is typically limited by the chaotic nature of the atmosphere. However, for some atmospheric phenomena, prediction skill on subseasonal-to-decadal timescales is increased when the initial conditions are in a particular state. In this study, we employ machine learning to identify sea surface temperature (SST) regimes that enhance prediction skill of North Atlantic atmospheric circulation. An ensemble of artificial neural networks is trained to predict anomalous, low-pass filtered 500 mb height at 7–8 weeks lead using SST. We then use self-organizing maps (SOMs) constructed from 9 regions within the SST domain to detect state-dependent prediction skill. SOMs are built using the entire SST time series, and we assess which SOM units feature confident neural network predictions. Four regimes are identified that provide skillful seasonal predictions of 500 mb height. Our findings demonstrate the importance of extratropical decadal SST variability in modulating downstream ENSO teleconnections to the North Atlantic. The methodology presented could aid future forecasting on subseasonal-to-decadal timescales.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 8","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD042917","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143840923","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}