AGU Advances最新文献

{"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}

{"title":"Anthropogenic Aerosols Have Significantly Weakened the Regional Summertime Circulation in the Northern Hemisphere During the Satellite Era","authors":"Joonsuk M. Kang,&nbsp;Tiffany A. Shaw,&nbsp;Lantao Sun","doi":"10.1029/2024AV001318","DOIUrl":"https://doi.org/10.1029/2024AV001318","url":null,"abstract":"<p>Reanalysis data show a significant weakening of summertime circulation in the Northern Hemisphere (NH) midlatitudes in the satellite era with implications for surface weather extremes. Recent work showed the weakening is not significantly affected by changes in the Arctic, but did not examine the role of different anthropogenic forcings such as aerosols. Here we use the Detection and Attribution Model Intercomparison Project (DAMIP) simulations to quantify the impact of anthropogenic aerosol and greenhouse gas forcing. The DAMIP simulations show aerosols and greenhouse gases contribute equally to zonal-mean circulation weakening. Regionally, aerosol dominates the Pacific storm track weakening whereas greenhouse gas dominates in the Atlantic. Using a regional energetic framework, we show why the impact of aerosol is the largest in the Pacific. Reduced sulfate aerosol emissions over Eurasia and North America increase (clear-sky) surface shortwave radiation and turbulent fluxes. This enhances land-to-ocean energy contrast and energy transport via stationary circulations to the ocean. Consequently, energy converges poleward of oceanic storm tracks, demanding weaker poleward energy transport storm tracks, and the storm tracks weaken. The impact is larger over the Pacific following the larger emission decrease over Eurasia than North America. Similar yet opposite, increased aerosol emissions over South and East Asia decrease shortwave radiation and weaken land-to-ocean energy transport. This diverges energy equatorward of the Pacific storm track, further weakening it. Our results show aerosols are a dominant driver of regional circulation weakening during the NH summertime in the satellite era and a regional energetic framework explaining the underlying processes.</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/10.1029/2024AV001318","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142707800","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":"Toward a Universal Model of Hyporheic Exchange and Nutrient Cycling in Streams","authors":"Ahmed Monofy,&nbsp;Stanley B. Grant,&nbsp;Fulvio Boano,&nbsp;Megan A. Rippy,&nbsp;Jesus D. Gomez-Velez,&nbsp;Sujay S. Kaushal,&nbsp;Erin R. Hotchkiss,&nbsp;Sydney Shelton","doi":"10.1029/2024AV001373","DOIUrl":"https://doi.org/10.1029/2024AV001373","url":null,"abstract":"<p>In this paper we demonstrate that several ubiquitous hyporheic exchange mechanisms can be represented simply as a one-dimensional diffusion process, where the diffusivity decays exponentially with depth into the streambed. Based on a meta-analysis of 106 previously published laboratory measurements of hyporheic exchange (capturing a range of bed morphologies, hydraulic conditions, streambed properties, and experimental approaches) we find that the reference diffusivity and mixing length-scale are functions of the permeability Reynolds Number and Schmidt Number. These dimensionless numbers, in turn, can be estimated for a particular stream from the median grain size of the streambed and the stream's depth, slope, and temperature. Application of these results to a seminal study of nitrate removal in 72 headwater streams across the United States, reveals: (a) streams draining urban and agricultural landscapes have a diminished capacity for in-stream and in-bed mixing along with smaller subsurface storage zones compared to streams draining reference landscapes; (b) under steady-state conditions nitrate uptake in the streambed is primarily biologically controlled; and (c) median reaction timescales for nitrate removal in the hyporheic zone are <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>≈</mo>\u0000 </mrow>\u0000 <annotation> ${approx} $</annotation>\u0000 </semantics></math>0.5 and 20 hr for uptake by assimilation and denitrification, respectively. While further research is needed, the simplicity and extensibility of the framework described here should facilitate cross-disciplinary discussions and inform reach-scale studies of pollutant fate and transport and their scale-up to watersheds and beyond.</p>","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"5 6","pages":""},"PeriodicalIF":8.3,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024AV001373","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142641953","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":"Emerging Climate Change Signals in Atmospheric Circulation","authors":"T. A. Shaw,&nbsp;J. M. Arblaster,&nbsp;T. Birner,&nbsp;A. H. Butler,&nbsp;D. I. V. Domeisen,&nbsp;C. I. Garfinkel,&nbsp;H. Garny,&nbsp;K. M. Grise,&nbsp;A. Yu. Karpechko","doi":"10.1029/2024AV001297","DOIUrl":"https://doi.org/10.1029/2024AV001297","url":null,"abstract":"<p>The circulation response to climate change shapes regional climate and extremes. Over the last decade an increasing number of atmospheric circulation signals have been documented, with some attributed to human activities. The circulation signals represent an exciting opportunity for improving our understanding of dynamical mechanisms, testing our theories and reducing uncertainties. The signals have also presented puzzles that represent an opportunity for better understanding the circulation response to climate change, its contribution to climate extremes, interactions with moisture, and connection to thermodynamic discrepancies. The next decade is likely to be a golden age for dynamics with many advances possible.</p>","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"5 6","pages":""},"PeriodicalIF":8.3,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024AV001297","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142641840","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":"Evidence for Magnetically-Driven Accretion in the Distal Solar System","authors":"Elias N. Mansbach,&nbsp;Benjamin P. Weiss,&nbsp;Eduardo A. Lima,&nbsp;Michael Sowell,&nbsp;Joseph L. Kirschvink,&nbsp;Roger R. Fu,&nbsp;Saverio Cambioni,&nbsp;Xue-Ning Bai,&nbsp;Jodie B. Ream,&nbsp;Chisato Anai,&nbsp;Atsuko Kobayashi,&nbsp;Hironori Hidaka","doi":"10.1029/2024AV001396","DOIUrl":"https://doi.org/10.1029/2024AV001396","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <p>Paleomagnetic measurements of meteorites indicate that magnetic fields existed in the inner solar nebula capable of driving accretion at rates similar to those observed for young stellar objects with protoplanetary disks. However, the field strength in the solar system beyond ∼7 astronomical units (AU) and its role in accretion remain poorly constrained. Returned samples from asteroid (162173) Ryugu offer the possibility of determining the nebular field intensity in this distal region. Here, we report paleomagnetic studies of three Ryugu particles which reveal that alteration occurred in the presence of a null or relatively weak (&lt;15.8 μT) field within 3 million years (Ma) after solar system formation. This resolves previously contrasting reports that Ryugu's parent body experienced alteration in the presence of a strong (&gt;80 μT) magnetic field and weak or null field (&lt;3 μT). In addition, we re-examine previous paleomagnetic and Mn-Cr chronometry studies of three other distally-sourced meteorites, Tagish Lake, Tarda, and Wisconsin Range 91600, which measured paleointensities of &lt;0.9, &lt;1.7 and 5.1 ± 4.5 μT respectively. While it was previously unclear whether these records were acquired while the nebula was present, our re-analysis suggests that their records are sufficiently old (i.e., &lt;3.5 Ma after solar system formation) to be nebular in origin. Collectively, these data demonstrate that the distal solar system nebular field, while faint, was likely still strong enough to drive accretion at rates like those observed in the inner solar system.</p>\u0000 </section>\u0000 </div>","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"5 6","pages":""},"PeriodicalIF":8.3,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024AV001396","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142596420","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}