AGU Advances最新文献

{"title":"Stronger Evidence of a Subsurface Ocean Within Callisto From a Multifrequency Investigation of Its Induced Magnetic Field","authors":"Corey J. Cochrane,&nbsp;Steven D. Vance,&nbsp;Julie C. Castillo-Rogez,&nbsp;Marshall J. Styczinski,&nbsp;Lucas Liuzzo","doi":"10.1029/2024AV001237","DOIUrl":"https://doi.org/10.1029/2024AV001237","url":null,"abstract":"<p>The magnetometer investigation of the Galileo mission used the phenomenon of magnetic induction to produce the most compelling evidence that subsurface oceans exist within our solar system. Although there is high certainty that the induced field measured at Europa is attributed to a global-scale subsurface ocean, there is still uncertainty around the possibility that the induced field measured at Callisto is evidence of an ocean. This uncertainty is due to the presence of a conductive ionosphere, which will also produce an induction signal in response to Jupiter's strong time-varying magnetic field. Therefore, it is not yet known whether the observed induced field is attributable to the ionosphere, an ocean, or a combination of both. In this work, we use previously published simulations of Callisto's plasma interaction in combination with both an inverse and an ensemble forward modeling method to highlight the plausible range of interior properties of Callisto. We further constrain the ocean thickness and conductivity, ice shell thickness, and ionospheric conductivity that are required to explain the Galileo magnetometer observations. This is the first study to jointly consider all flybys to constrain the driving field and three flybys (C03, C09, and C10) to assess the induction response. Our results suggest that Callisto's response more likely arises from the combination of a thick conductive ocean and an ionosphere rather than from an ionosphere alone.</p>","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"6 1","pages":""},"PeriodicalIF":8.3,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024AV001237","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143121028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Net Radiative Effect of the Ill-Defined Clear-Sky in the Vicinity of Clouds","authors":"Eshkol Eytan,&nbsp;Jake J. Gristey,&nbsp;Graham Feingold","doi":"10.1029/2024AV001407","DOIUrl":"https://doi.org/10.1029/2024AV001407","url":null,"abstract":"&lt;p&gt;Clouds play a crucial role in Earth's energy budget resulting in significant deviations from clear-sky fluxes. This important role, combined with their complexity, makes them a major source of uncertainty in climate projections. Over the past two decades, the radiative signatures of clouds in their surroundings have been extensively studied, highlighting the challenges of defining clouds and distinguishing them from the aerosol embedded in clear-sky. Accurately defining clouds and aerosol is essential for quantifying their radiative effects and for remote sensing of the surface and atmosphere under clear-sky conditions. In this study, we combine two of the most mature and sophisticated space-borne instruments: the MODerate resolution Imaging Spectroradiometer with its high-resolution multispectral images and the Clouds and the Earth's Radiant Energy System broadband top-of-the-atmosphere radiative flux data. This0 allows us to quantify the net RE of clouds within the clear-sky around them for the first time. Our findings show that the local RE of clouds over the ocean around noon ranges from −7 to −10 W &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;m&lt;/mi&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${mathrm{m}}^{-2}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; in the solar band and 1–1.5 W &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;m&lt;/mi&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${mathrm{m}}^{-2}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; in the longwave infrared. These results suggest that clouds drive a significant portion of the aerosol direct RE. Additionally, the near-cloud longwave infrared effect is equivalent to an effect of &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;∼&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${sim} $&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;90 ppm of &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mtext&gt;CO&lt;/mtext&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${text{CO}}_{2}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;. We propose to categorize the sky into three regimes—cloudy, cloud-influenced-clear-sky, and far-field clear-sky and suggest a path to move beyond a discrete definition of the sky. This will improve our understanding of the role of clouds ","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"6 1","pages":""},"PeriodicalIF":8.3,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024AV001407","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143120581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pliocene Warmth and Patterns of Climate Change Inferred From Paleoclimate Data Assimilation","authors":"Jessica E. Tierney,&nbsp;Jonathan King,&nbsp;Matthew B. Osman,&nbsp;Jordan T. Abell,&nbsp;Natalie J. Burls,&nbsp;Ehsan Erfani,&nbsp;Vincent T. Cooper,&nbsp;Ran Feng","doi":"10.1029/2024AV001356","DOIUrl":"https://doi.org/10.1029/2024AV001356","url":null,"abstract":"&lt;p&gt;As the last time period when &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mtext&gt;CO&lt;/mtext&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${text{CO}}_{2}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; concentrations were near 400 ppm, the Pliocene Epoch (5.33–2.58 Ma) is a useful paleoclimate target for understanding future climate change. Existing estimates of global warming and climate sensitivity during the Pliocene rely mainly on model simulations. To reconstruct Pliocene climate and incorporate paleoclimate observations, we use data assimilation to blend sea-surface temperature (SST) proxies with model simulations from the Pliocene Modeling Intercomparison Project 2 and the Community Earth System Models. The resulting reconstruction, “plioDA,” suggests that the mid-Pliocene (3.25 Ma) was warmer than previously thought (on average 4.1°C warmer than preindustrial, 95% CI = 3.0°C–5.3°C), leading to a higher estimate of climate sensitivity (4.8°C per doubling of &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mtext&gt;CO&lt;/mtext&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${text{CO}}_{2}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, 90% CI = 2.6°C–9.9°C). In agreement with previous work, the tropical Pacific zonal SST gradient during the mid-Pliocene was moderately reduced (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;mn&gt;0.8&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${-}0.8$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;°C, 95% CI = &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;mn&gt;2.3&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${-}2.3$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;–0.4°C). However, this gradient was more reduced during the early Pliocene (4.75 Ma, &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;mn&gt;2.3&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${-}2.3$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;°C, 95% CI = &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;mn&gt;3.9&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${-}3.9$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;–&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;mn&gt;1.1&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${-}1.1$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;°C), a time period that","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"6 1","pages":""},"PeriodicalIF":8.3,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024AV001356","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143120055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ceres: Organic-Rich Sites of Exogenic Origin?","authors":"R. Sarkar,&nbsp;A. Nathues,&nbsp;M. Hoffmann,&nbsp;E. Cloutis,&nbsp;K. Mengel,&nbsp;P. Singh,&nbsp;G. Thangjam,&nbsp;J. Hernandez,&nbsp;S. Karunatillake,&nbsp;M. Coutelier","doi":"10.1029/2024AV001362","DOIUrl":"https://doi.org/10.1029/2024AV001362","url":null,"abstract":"<p>Ceres, the largest object in the asteroid belt, is the only potential ocean world in the inner Solar System. Previous studies identified deposits of aliphatic organics in and around the Ernutet crater, and at small locations at Inamahari and Urvara craters. The origin of organics, either endogenic or exogenic, in these fresh exposures is still under debate. This study addresses the origin of the organics by analyzing their global distribution and geologic context. Our first step involved a global search for organic-rich sites that might have escaped previous detections. We achieved this by using a deep neural network, utilizing spectral redness in the Dawn's Framing Camera multispectral data to identify potential organic-rich sites. The identified sites were further studied by using IR spectrometer data to infer the compositions of materials showing spectral redness. Of the newly identified red-sloped sites, only two can be considered certain to be organic-rich. We also identified sites with spectral redness, but without any signature of organics in their infrared spectra. These sites could be attributed to the aqueous alteration of magnetite into ferric-iron bearing phases. At Ernutet, Inamahari, and Urvara, the organic-rich material is confined to the near surface only. Additionally, the absence of tectonic/volcanic features at these sites makes an endogenic origin questionable. The global rarity of detectable organics also supports this assessment. Consequently, we suggest that organics at these sites were originally delivered by low-velocity, organic-rich impactor(s) from the main belt and subsequently excavated, rather than originating from endogenous processes.</p>","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"6 1","pages":""},"PeriodicalIF":8.3,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024AV001362","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143119617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Distinct Energy Budgets of Mars and Earth","authors":"Larry Guan,&nbsp;Liming Li,&nbsp;Ellen C. Creecy,&nbsp;Xun Jiang,&nbsp;Xinyue Wang,&nbsp;Germán Martínez,&nbsp;Anthony D. Toigo,&nbsp;Mark I. Richardson,&nbsp;Agustín Sánchez-Lavega,&nbsp;Yeon Joo Lee","doi":"10.1029/2024AV001389","DOIUrl":"https://doi.org/10.1029/2024AV001389","url":null,"abstract":"<p>The radiant energy budget (REB) is a fundamental physical parameter for planetary bodies, though studies constraining the REB for bodies beyond Earth are relatively limited. We generate the first meridional profiles of Mars' REB at seasonal and annual timescales through measurements based on long term multi-instrument observations from spacecraft orbiting Mars. Then, we compare our findings to Earth's REB using contemporary satellite data sets. Each planet exhibits remarkably distinct seasonal REB distributions due to differences in their orbital, atmospheric, and surface properties. Annually, Earth's REB exhibits a tropical energy surplus and a deficit at the poles. In contrast, Mars' annual REB displays an inverted meridional distribution with significant hemispheric asymmetry. Additionally, global dust storms significantly modify the Martian REB. Our observations are employable in future studies to improve models on Mars' general circulation, meteorology, and polar ice cap evolution.</p>","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"5 6","pages":""},"PeriodicalIF":8.3,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024AV001389","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142862051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of Mesoscale Eddies on Southern Ocean Biogeochemistry","authors":"Lydia Keppler,&nbsp;Yassir A. Eddebbar,&nbsp;Sarah T. Gille,&nbsp;Nicola Guisewhite,&nbsp;Matthew R. Mazloff,&nbsp;Veronica Tamsitt,&nbsp;Ariane Verdy,&nbsp;Lynne D. Talley","doi":"10.1029/2024AV001355","DOIUrl":"https://doi.org/10.1029/2024AV001355","url":null,"abstract":"&lt;p&gt;The Southern Ocean is rich in highly dynamic mesoscale eddies and substantially modulates global biogeochemical cycles. However, the overall surface and subsurface effects of eddies on the Southern Ocean biogeochemistry have not been quantified observationally at a large scale. Here, we co-locate eddies, identified in the Meta3.2DT satellite altimeter-based product, with biogeochemical Argo floats to determine the effects of eddies on the dissolved inorganic carbon (DIC), nitrate, and dissolved oxygen concentrations in the upper 1,500 m of the ice-free Southern Ocean, as well as the eddy effects on the carbon fluxes in this region. DIC and nitrate concentrations are lower in anticyclonic eddies (AEs) and increased in cyclonic eddies (CEs), while dissolved oxygen anomalies switch signs above (CEs: positive, AEs: negative) and below the mixed layer (CEs: negative, AEs: positive). We attribute these anomalies primarily to eddy pumping (isopycnal heave), as well as eddy trapping for oxygen. Maximum anomalies in all tracers occur at greater depths in the subduction zone north of the Antarctic Circumpolar Current (ACC) compared to the upwelling region in the ACC, reflecting differences in background vertical structures. Eddy effects on air–sea &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mtext&gt;CO&lt;/mtext&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${text{CO}}_{2}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; exchange have significant seasonal variability, with additional outgassing in CEs in fall (physical process) and additional oceanic uptake in AEs and CEs in spring (biological and physical process). Integrated over the Southern Ocean, AEs contribute &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;∼&lt;/mo&gt;\u0000 &lt;mn&gt;0.03&lt;/mn&gt;\u0000 &lt;mo&gt;±&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${sim} 0.03pm $&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; 0.01 Pg C &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msup&gt;\u0000 &lt;mtext&gt;yr&lt;/mtext&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${text{yr}}^{-1}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; (7 &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;±&lt;/mo&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;mi&gt;%&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $pm 2%$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;) to the Southern Ocean carbon uptake, and CEs offset this by &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 ","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"5 6","pages":""},"PeriodicalIF":8.3,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024AV001355","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142758052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Petrology and Geochemistry of the 2021 Fagradalsfjall Eruption, Iceland: An Eruption Sourced From Multiple, Compositionally Diverse, Near-Moho Sills","authors":"E. W. Marshall,&nbsp;A. Caracciolo,&nbsp;E. Bali,&nbsp;S. A. Halldórsson,&nbsp;S. Matthews,&nbsp;E. Ranta,&nbsp;M. B. Rasmussen,&nbsp;J. G. Robin,&nbsp;G. H. Guðfinnson,&nbsp;J. Maclennan,&nbsp;C. Bosq,&nbsp;D. Auclair,&nbsp;O. Sigmarsson,&nbsp;H. Merrill,&nbsp;B. Gísladóttir,&nbsp;S. Johnson,&nbsp;N. Löw,&nbsp;A. Stracke,&nbsp;F. Genske","doi":"10.1029/2024AV001310","DOIUrl":"https://doi.org/10.1029/2024AV001310","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <p>Magmatic processes at the crust-mantle boundary (i.e., Moho) are commonly studied <i>post facto</i> at fossil ophiolites, oceanic core complexes, or inferred from the compositions of crystals or melt inclusions. The 2021 eruption at Fagradalsfjall on the Reykjanes Peninsula, Iceland, was supplied from magma bodies near the Moho and offers a unique opportunity to study the timescales, structure, and syn-eruptive processes of near-Moho magmatic systems at ∼15 km depth. Here, we present a comprehensive petrological and geochemical investigation of the full 183 day eruption that is based on frequent sampling of the eruption. Lavas erupted in the first 45 days displayed significant and sudden changes in geochemistry, followed by lower amplitude fluctuations until the end of the eruption. This variability can be explained by contribution from multiple magma bodies, as best distinguished using Sr-Nd-Hf-Pb isotope systematics. The lavas display unusual trace element and radiogenic isotope compositions compared to other Icelandic basalts, but are similar to other rare, highly incompatible element enriched lavas on the Reykjanes Peninsula, and thus these lavas may represent a distinct suite of Reykjanes Peninsula basalts. Our geochemical and petrological observations show that numerous, compositionally variable bodies of magma must exist in the lowermost crust or at the crust-mantle boundary. These near-Moho magma bodies transfer magma between one another on timescales as short as days-to-months, but partially crystallize over longer time periods, and periodically inject into the overlying crust.</p>\u0000 </section>\u0000 </div>","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"5 6","pages":""},"PeriodicalIF":8.3,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024AV001310","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142737575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Imaging Magma Reservoirs From Space With Altimetry-Derived Gravity Data","authors":"Hélène Le Mével","doi":"10.1029/2024AV001403","DOIUrl":"https://doi.org/10.1029/2024AV001403","url":null,"abstract":"<p>I investigate the detectability of magma reservoirs in the vertical gravity gradient (VGG) anomalies calculated from satellite altimetry data. First, I calculate a suite of synthetic seamount models to show the expected VGG anomaly characteristic wavelength and amplitude for a simplified magmatic system, hydrothermal system, and a caldera infill, varying their dimensions for a given depth and density contrast. I find that most magmatic and hydrothermal systems create VGG anomalies with a characteristic wavelength and amplitude greater than the data uncertainty and are therefore detectable. The proposed approach consists in three main steps: (a) calculate the VGG from the two components of the deflection of the vertical, (b) calculate and remove the gravity contribution of the bathymetry interface using an independent bathymetry data set (e.g., acquired by multibeam echosounders) to obtain a VGG Bouguer gravity anomaly, (c) invert the Bouguer VGG anomaly to obtain a 3D density model. I image a 6-by-8-km low density body between 3 and 9 km depth under Brothers volcano in the Kermadec arc. I hypothesize that it represents the main magmatic system, possibly with a minor fraction of hydrothermal fluids at the shallower depths. There are about 225 submarine volcanoes globally that could be studied with satellite altimetry-derived gravity data to potentially image their magmatic system. Future altimetry data will increase the gravity data resolution and allow us to image smaller features. This is thus an invaluable data set for the study of underexplored submarine volcanoes and can help improve our volcano hazards assessment.</p>","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"5 6","pages":""},"PeriodicalIF":8.3,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024AV001403","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142737585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Magnetospheric Control of Ionospheric TEC Perturbations via Whistler-Mode and ULF Waves","authors":"Yangyang Shen,&nbsp;Olga P. Verkhoglyadova,&nbsp;Anton Artemyev,&nbsp;Michael D. Hartinger,&nbsp;Vassilis Angelopoulos,&nbsp;Xueling Shi,&nbsp;Ying Zou","doi":"10.1029/2024AV001302","DOIUrl":"https://doi.org/10.1029/2024AV001302","url":null,"abstract":"&lt;p&gt;The weakly ionized plasma in the Earth's ionosphere is controlled by a complex interplay between solar and magnetospheric inputs from above, atmospheric processes from below, and plasma electrodynamics from within. This interaction results in ionosphere structuring and variability that pose major challenges for accurate ionosphere prediction for global navigation satellite system (GNSS) related applications and space weather research. The ionospheric structuring and variability are often probed using the total electron content (TEC) and its relative perturbations (dTEC). Among dTEC variations observed at high latitudes, a unique modulation pattern has been linked to magnetospheric ultra-low-frequency (ULF) waves, yet its underlying mechanisms remain unclear. Here using magnetically conjugate observations from the THEMIS spacecraft and a ground-based GPS receiver at Fairbanks, Alaska, we provide direct evidence that these dTEC modulations are driven by magnetospheric electron precipitation induced by ULF-modulated whistler-mode waves. We observed peak-to-peak dTEC amplitudes reaching &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;∼&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${sim} $&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; 0.5 TECU (1 TECU is equal to &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msup&gt;\u0000 &lt;mn&gt;10&lt;/mn&gt;\u0000 &lt;mn&gt;6&lt;/mn&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${10}^{6}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; electrons/&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;m&lt;/mi&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${mathrm{m}}^{2}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;) with modulations spanning scales of &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;∼&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${sim} $&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; 5–100 km. The cross-correlation between our modeled and observed dTEC reached &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;∼&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${sim} $&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; 0.8 during the conjugacy period but decreased outside of it. The spectra of whistler-mode waves and dTEC also matched closely at ULF frequencies during the conjugacy period but diverged outside of it. Our findings elucidate the high-latitude dTEC generation from magnetospheric wave-induced precipitation, addressing a significant gap in current physics-based dTEC modeling. Theses results thus improve ionospheric dTEC prediction and enhance our unde","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"5 6","pages":""},"PeriodicalIF":8.3,"publicationDate":"2024-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024AV001302","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142708127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Earth-Based Transmitters Trigger Precipitation of Inner Radiation Belt Electrons: Unveiling Observations and Modeling Results","authors":"Zheng Xiang,&nbsp;Xinlin Li,&nbsp;Daniel N. Baker,&nbsp;Yang Mei,&nbsp;Declan O'Brien,&nbsp;Benjamin Hogan,&nbsp;Hong Zhao,&nbsp;David Brennan,&nbsp;Binbin Ni,&nbsp;Theodore Sarris,&nbsp;Michael A. Temerin","doi":"10.1029/2024AV001354","DOIUrl":"https://doi.org/10.1029/2024AV001354","url":null,"abstract":"<p>Human activity influence Earth's environment, including the space environment hundreds to thousands of kilometers above the Earth. One direct evidence is that the 19.8 kHz electromagnetic signals launched by the North West Cape (NWC) transmitter station in Australia produce a wisp-like energy distribution of precipitating energetic electrons in Earth's inner radiation belt, observed by many Low Earth Orbiting satellites. Typically, satellites observe a single wisp with energy that decreases with increasing L (approximately the radial distance in the equatorial plane), which is produced by a first-order cyclotron resonance of transmitter signals with energetic electrons. Here we report, for the first time, multiple wisps observed by the Relativistic Electron and Proton Telescope integrated little experiment-2 (REPTile-2) on board the recently launched Colorado Inner Radiation Belt Experiment (CIRBE) CubeSat. Based on simulation results, we demonstrate that harmonic cyclotron resonances including the 1, −1, and 2 orders by highly oblique NWC transmitter signals produce these multiple wisps. The discovery of multiple-order cyclotron resonances simultaneously occurring in space sheds new light on wave-particle interactions in near-Earth space. It also has implications for developing artificial radiation belt remediation techniques and understanding the propagation and scattering of plasma waves in planetary magnetospheres.</p>","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"5 6","pages":""},"PeriodicalIF":8.3,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024AV001354","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142707801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}