The 18O/16O ratios of biominerals have been widely used for reconstructing ecophysiology and climatic settings of modern and extinct animals. However, the 18O/16O ratios of body water, which largely determine the 18O/16O ratios of biominerals, are influenced by a host of competing factors. Regional climate and local hydrology are dominant controls on water isotopic composition before water is consumed by an animal. Behavioral and physiological factors, modified by local climate, also have a strong influence on body water compositions. The addition of a third isotope, 17O (expressed as Δ’17O) potentially allows for further resolution of these factors. Here we construct a generalized triple oxygen isotope mass balance model based on the 18O model of (Kohn 1996) (Geochim. Cosmochim. Acta 60, 4811–4829) and examine the influence on vertebrate animal body water Δ’17O of numerous climatic, ecological, and isotopic variables. We evaluate the model against new and previously published triple oxygen isotope data from modern and fossil animals. The model predicts that animals from arid environments will have wider ranges and lower minimum values of body water Δ’17O than animals living in humid environments. Leaf water consumers are more sensitive to variations in relative humidity and have lower Δ’17O than surface water consumers, which more closely track meteoric water compositions. In this model, factors such as body mass and relative proportions of evaporative versus nonevaporative effluxes from the animal have a lesser influence on animal Δ’17O. If δ18O of meteoric water is invariant, body water isotopic compositions will form approximately linear arrays in Δ’17O versus δ18O space with slopes of ∼0.52. Study of Δ’17O becomes most useful when δ18O of meteoric water is variable or unknown (as is generally the case for fossil animals); in this case Δ’17O of body water responds more strongly to changes in relative humidity, evaporated water inputs, and animal water use efficiency. These predictions are generally supported by observations of Δ’17O for modern animals. This agreement suggests that Δ’17O analysis of animal tissues has great potential as a paleo-aridity proxy in continental environments and as a proxy for learning about the ecology of modern and extinct animals.

Vegetated coastal ecosystems (mangroves, seagrasses, and saltmarshes, often called Blue Carbon ecosystems) store large carbon stocks. However, their regional carbon inventories, sequestration rates, and potential as natural climate change mitigation strategies are poorly constrained. Here, we systematically review organic carbon storage and accumulation rates in vegetated coastal ecosystems across the Central and Southwestern Atlantic, extending from Guyana (08.28°N) to Argentina (55.14°S). We estimate that 0.4 Pg organic carbon is stored in the region, which is approximately 2-5% of global carbon stores in coastal vegetated systems, and that they accumulate 0.5 to 3.9 Tg carbon annually. By ecosystem type, mangroves have the largest areal extent and contribute 70-80% of annual organic carbon accumulation, with Brazil hosting roughly 95% of mangrove stocks. Our findings suggest that organic carbon accumulation in the region is equivalent to 0.7 to 13% of global rates in vegetated coastal ecosystems, indicating the importance of conserving these ecosystems as a nature-based approach for mitigating and adapting to climate change.

Abstract We explore the capabilities of volcano opto‐acoustics, a promising technique for measuring explosion and infrasound resonance phenomena at open‐vent volcanoes. Joint visual and infrasound study at Yasur Volcano (Vanuatu) demonstrate that even consumer‐grade cameras are capable of recording infrasound with high fidelity. Passage of infrasonic waves, ranging from as low as 5 Pa to hundreds of Pa, from both explosions and persistent tremor, pressurizes and depressurizes ambient plumes inducing visible vaporization and condensation respectively. Optical tracking of these pressure wavefields can be used to identify spectral characteristics, which vary within Yasur's two deep craters and are distinct for explosion and tremor sources. Wavefield maps can illuminate the propagation of blasts as well as the dynamics of persistent infrasonic tremor associated with standing waves in the craters. We propose that opto‐acoustic monitoring is useful for extraction of near‐vent infrasound signal and for tracking volcanic unrest from a remote distance.

Infrasound may be used to detect the approach of hazardous volcanic mudflows, known as lahars, tens of minutes before their flow fronts arrive. We have analyzed signals from more than 20 secondary lahars caused by precipitation events at Fuego Volcano during Guatemala's rainy season in May through October of 2022. We are able to quantify the capabilities of infrasound monitoring through comparison with seismic data, time lapse camera imagery, and high-resolution video of a well-recorded event on August 17. We determine that infrasound sensors, deployed adjacent to the lahar path and in small-aperture (10 s of meters) arrays, are particularly sensitive to remote detection of lahars, including small-sized events, at distances of at least 5 km. At Fuego Volcano these detections could be used to provide timely alerts of up to 30 min before lahars arrive at a downstream monitoring site, such as in the frequently impacted Ceniza drainage. We propose that continuous infrasound monitoring, from locations adjacent to a drainage, may complement seismic monitoring and serve as a valuable tool to help identify approaching hazards. On the other hand, infrasound arrays located a kilometer or more from the lahar path can be effectively used to track a lahar's progression.

<p>Elevation is a key control on the frequency and duration of flooding experienced by a salt marsh over the course of the tidal cycle, which in turn modulates the deposition of sediment onto the marsh surface. The amount of sediment deposited onto the marsh surface is an important factor in the development of the salt marsh and its ability to withstand sea level rise. Human interference in the form of agricultural practices (e.g., ditching and embayments) and mosquito control significantly altered the structure and function of salt marshes throughout New England with lasting impacts on marsh platform elevation and, consequently, the persistence of salt marshes in the face of sea level rise. This study establishes the present-day distribution of elevation and vegetation zones for a salt marsh in Maine, United States, and compares these baseline measurements to past estimates of elevation made using carbon stable isotopes (δ<sup>13</sup>C) measured in sediment cores. A LiDAR scan and a series of multispectral air photos were collected from a representative salt marsh in Maine (Cousins River Marsh, Yarmouth, ME). The LiDAR scan is processed to create a digital elevation model (DEM) of the marsh and the air photos are converted into a 2D digital model of the marsh platform. In New England salt marshes, an elevation-mediated gradient in vegetation exists across the marsh surface, with the most salt-tolerant species residing in lower-elevation areas. Different species of marsh grasses produce varying δ<sup>13</sup>C values, and once incorporated into the marsh peat, can potentially be used to identify changes in vegetation cover through time. Sediment cores collected from Cousins River are sub-sampled and analyzed for down-core variations in δ<sup>13</sup>C to assess salt marsh paleovegetation. Short-term radioisotopes <sup>210</sup>Pb and<sup> 137</sup>Cs are used to produce age-depth models by integrating sedimentation over ~100 and ~70 years, respectively, and are correlated to stable carbon isotope results for an approximation of salt marsh elevation change. Results will inform our understanding of the relative influences of sea level rise and human-driven landscape alteration on salt marsh morphodynamics along the coast of Maine, with implications for salt marshes throughout New England.</p>

The Gulf of Maine, located in the western North Atlantic, has undergone recent, rapid ocean warming but the lack of long-term, instrumental records hampers the ability to put these significant hydrographic changes into context. Here we present multiple 300-year long geochemical records (oxygen, nitrogen, and previously published radiocarbon isotopes) measured in absolutely-dated Arctica islandica shells from the western Gulf of Maine. These records, in combination with climate model simulations, suggest that the Gulf of Maine underwent a long-term cooling over most of the last 1000 years, driven primarily by volcanic forcing and North Atlantic ocean dynamics. This cooling trend was reversed by warming beginning in the late 1800s, likely due to increased atmospheric greenhouse gas concentrations and changes in western North Atlantic circulation. The climate model simulations suggest that the warming over the last century was more rapid than almost any other 100-year period in the last 1000 years in the region.

We studied a triggered snow avalanche (∼60 s in duration and with ∼1,100 m run‐out) using a network of infrasound arrays and time‐synced video, with the objective of understanding the relationship between infrasound generation and flow dynamics. Using standard array processing techniques, we compared the infrasound source back azimuths with the avalanche flow path identified by frame‐differenced, geo‐referenced video. Results show that infrasound records begin with direct arrivals followed by echoes from the avalanche‐triggering explosions and these decay within 35 s of the detonations. Subsequent infrasound, which lasts 20–30 s, could then be attributed exclusively to the avalanche. These infrasound detections, and their triangulated source locations, progress downhill over time and the most intense infrasound appears to originate from a steep, mid‐path cliff band, where the avalanche reached speeds in excess of 30 m/s and accelerations of more than 5 m/s 2 . The recorded infrasound was compared to two candidate source models extracted from video: total flow motion and advancing flow motion. Advancing source locations were compared to acoustic intensity time series using a nonnegative least squares inversion to solve for, and to quantify, time‐varying infrasound source intensity. We observed that certain portions of the flow, most notably the early stages and the end stages (when the powder cloud was expanding and settling) were infrasonically quiet.

Characterizing energy flow and trophic linkages is fundamental to understanding the functioning and resilience of Arctic ecosystems under increasing pressure from climate change and anthropogenic exploitation. We used carbon and nitrogen stable isotopes to examine trophic dynamics and the relative contribution of terrestrial organic matter, water column phytoplankton, and phytobenthos (benthic micro- and macro-autotrophs as well as sea ice algae) to the food webs supporting 45 macroconsumers in three Arctic coastal lagoon ecosystems (Krusenstern, Sisualik, Akulaaq) and the adjacent Kotzebue Sound with varying degrees of connectivity in Cape Krusenstern National Monument, Alaska. A two-source (water column particulate organic matter and benthic sediment organic matter), two-isotope trophic dynamics model informed by a Bayesian isotope mixing model revealed that the Lagoon-Kotzebue Sound coastal ecosystem supported consumers along a trophic position continuum from primary consumers, including amphipods, copepods, and clams to trophic level five predators, such as seastars, piscivorous fishes, seals, and seabirds. The relative contribution of the three primary producer end members, terrestrial organic matter (41 +/- 21%), phytoplankton (25 +/- 21%), and phytobenthos (34 +/- 23%) varied as a function of: 1) consumer foraging ecology and 2) consumer location. Suspension feeders received most of their carbon from food webs based on phytoplankton (49 +/- 11%) and terrestrial organic matter (23 +/- 5%), whereas herbivores and detritivores received the majority of their carbon from phytobenthos-based food webs, 58 +/- 10% and 60 +/- 8%, respectively. Omnivores and predators showed more even distributions of resource reliance and greater overall variance among species. Within the invertebrates, the importance of terrestrial organic matter decreased and phytobenthos increased with increasing trophic position. The importance of terrestrial organic matter contribution increased with lagoon proximity to major rivers inputs and isolation from Kotzebue Sound. Several taxa with cultural and subsistence food importance to local communities showed significant reliance (30-90% of baseline carbon) on food chains linked to fresh terrestrial organic matter. Our study indicates that terrestrial-marine linkages are important to the function of Arctic coastal lagoon ecosystems and artisanal fisheries. These linkages are likely to strengthen in the future with regional changes in erosion and runoff associated with climate change and anthropogenic disturbance.

The15N/14N ratio of the fish-native organic matter preserved in fish otoliths (or δ15Noto) may allow for reconstruction of fish trophic history and changes in food webs. To support this application, ground-truthing data are needed on the relationships among the δ15N of diet, of fish tissue (e.g., white muscle tissue, δ15Nwmt), and δ15Noto. Using a highly sensitive method for N isotope analysis, δ15Notowas compared with δ15Nwmtin 24 teleost species. Within a species, the difference between δ15Notoand δ15Nwmt(Δδ15No-w) varied little across individuals, confirming the utility of δ15Nototo reconstruct δ15Nwmtchanges for a given species. Across species, δ15Notoand δ15Nwmtwere highly correlated. However, Δδ15No-wvaried systematically across species. Phylogeny, the concentrations of total N and amino acids, and life history were ruled out as the main cause for the observed variation in Δδ15No-w. δ15Notowas lowest relative to δ15Nwmtin species producing larger otoliths. We propose that δ15Notois elevated by isotopically fractionating metabolism of the organic matrix, which is less important when otolith growth is fast and thus when the otolith is large.

Earth and Space Science Open Archive This work has been accepted for publication in Geophysical Research Letters. Version of RecordESSOAr is a venue for early communication or feedback before peer review. Data may be preliminary. Learn more about preprints. preprintOpen AccessYou are viewing an older version [v2]Go to new versionA Post-2013 Drop-off in Total Ozone at a Third of Global Ozonesonde Stations: ECC Instrument Artifacts?Authors Ryan Michael Stauffer iD Anne M. Thompson iD Debra E Kollonige iD Jacquelyn Cecile Witte iD David W. Tarasick Jonathan Davies Holger Voemel iD Gary A. Morris iD Roeland VanMalderen iD Bryan J. J. Johnson Richard Querel iD Henry B Selkirk iD Rene Stuebi Herman G.J. Smit See all authors Ryan Michael StaufferiDCorresponding AuthorNASA Goddard Space Flight CenteriDhttps://orcid.org/0000-0002-8583-7795view email addressThe email was not providedcopy email addressAnne M. ThompsoniDNASA-GODDARDiDhttps://orcid.org/0000-0002-7829-0920view email addressThe email was not providedcopy email addressDebra E KollonigeiDUniversity of Maryland - Earth System Science Interdisciplinary CenteriDhttps://orcid.org/0000-0002-6597-328Xview email addressThe email was not providedcopy email addressJacquelyn Cecile WitteiDNational Center for Atmospheric ResearchiDhttps://orcid.org/0000-0002-4110-5277view email addressThe email was not providedcopy email addressDavid W. TarasickEnvironment and Climate Change Canadaview email addressThe email was not providedcopy email addressJonathan DaviesEnvironment Canadaview email addressThe email was not providedcopy email addressHolger VoemeliDUnknowniDhttps://orcid.org/0000-0003-1223-3429view email addressThe email was not providedcopy email addressGary A. MorrisiDSt. Edward's UniversityiDhttps://orcid.org/0000-0002-2196-8454view email addressThe email was not providedcopy email addressRoeland VanMaldereniDRoyal Meteorological Institute of BelgiumiDhttps://orcid.org/0000-0002-1369-8853view email addressThe email was not providedcopy email addressBryan J. J. JohnsonNOAA ESRLview email addressThe email was not providedcopy email addressRichard QuereliDNational Institute of Water & Atmospheric Research (NIWA)iDhttps://orcid.org/0000-0001-8792-2486view email addressThe email was not providedcopy email addressHenry B SelkirkiDGoddard Earth Sciences and Technology Center, University of Maryland, Baltimore CountyiDhttps://orcid.org/0000-0001-9431-5385view email addressThe email was not providedcopy email addressRene StuebiMeteoSwissview email addressThe email was not providedcopy email addressHerman G.J. SmitForschungszentrum Juelich, Germanyview email addressThe email was not providedcopy email address

We recorded a M WR 3.6 earthquake in Idaho (USA) on 7 April 2020 with a network of six three‐element infrasound arrays and co‐located broadband seismometers situated within 25 km of the hypocenter. Infrasound array processing is used to identify the arrival of seismic‐to‐atmospheric coupled phases and as much as 90 s of infrasound coda. Apparent velocities ranging from seismic speeds to subhorizontal atmospheric sound speeds are attributed to a superposition of coincident waves arriving at the arrays. We find that the arriving infrasound originates from a broad range of back azimuths that deviates from epicentral back azimuth and indicates the ubiquity of secondary radiators for this relatively small earthquake. Secondary radiators, which often locate in regions of elevated topography, are identified using backprojections and earthquake initiation time. Analysis of infrasound sources from proximal earthquakes can be used to map ground shaking distributions, which are important for assessment of earthquake hazards.

In a series of 10-day campaigns in Ontario and Quebec, Canada, between 2005 and 2007, ozonesondes were launched twice daily in conjunction with continuous high-resolution wind-profiling radar measurements. Windprofilers can measure rapid changes in the height of the tropopause, and in some cases follow stratospheric intrusions. Observed stratospheric intrusions were studied with the aid of a Lagrangian particle dispersion model and the Canadian operational weather forecast system. Definite stratosphere-troposphere transport (STT) events occurred approximately every 2-3 days during the spring and summer campaigns, whereas during autumn and winter, the frequency was reduced to every 4-5 days. Although most events reached the lower troposphere, only three events appear to have significantly contributed to ozone amounts in the surface boundary layer. Detailed calculations find that STT, while highly variable, is responsible for an average, over the seven campaigns, of 3.1% of boundary layer ozone (1.2 ppb), but 13% (5.4 ppb) in the lower troposphere and 34% (22 ppb) in the middle and upper troposphere, where these layers are defined as 0-1 km, 1-3 km, and 3-S km respectively. Estimates based on counting laminae in ozonesonde profiles, with judicious choices of ozone and relative humidity thresholds, compare moderately well, on average, with these values. The lamina detection algorithm is then applied to a large dataset from four summer ozonesonde campaigns at 18 North American sites between 2006 and 2011. The results show some site-to-site and year-to-year variability, but stratospheric ozone contributions average 4.6% (boundary layer), 15% (lower troposphere) and 26% (middle/upper troposphere). Calculations were also performed based on the TOST global 3D trajectory-mapped ozone data product. Maps of STT in the same three layers of the troposphere suggest that the STT ozone flux is greater over the North American continent than Europe, and much greater in winter and spring than in summer or fall. When averaged over all seasons, magnitudes over North America show similar ratios between levels to the previous calculations, but are overall 3-4 times smaller. This may be because of limitations (trajectory length and vertical resolution) to the current TOST-based calculation.

Data from ground-based ozone (O3) vertical profiling platforms operated during the FRAPPE/DISCOVER-AQ campaigns in summer 2014 were used to characterize key processes responsible for establishing O3 profile development in the boundary layer in the Northern Colorado Front Range. Morning mixing from the upper boundary layer and lower free troposphere into the lower boundary layer was the key process establishing the mid-morning boundary layer O3 mixing ratio. Photochemical O3 production throughout the boundary layer builds on the mid-morning profile. From late morning to mid-afternoon the continuing O3 increase was nearly uniform through the depth of the profile measured by the tethersonde (~400 m). Ozonesondes flown on a near daily schedule over a four week period with multiple profiles on a number of days captured the full 1500 to 2000 m vertical extent of O3 enhancements in the mixed boundary layer confirming O3 production throughout the entire boundary layer. Continuous O3 measurements from the Boulder Atmospheric Observatory (BAO) tall tower at 6 m and 300 m showed hourly O3 at the 6 m level ≥75 ppb on 15% of the days. The diurnal variation on these days followed a pattern similar to that seen in the tethersonde profiles. The association of high O3 days at the BAO tower with transport from sectors with intense oil and natural gas production toward the northeast suggests emissions from this industry were an important source of O3 precursors and are crucial in producing peak O3 events in the NCFR. Higher elevation locations to the west of the NCFR plains regularly experience higher O3 values than those in the lower elevation NCFR locations. Exposure of populations in these areas is not captured by the current regulatory network, and likely underestimated in population O3 exposure assessments.

Ozonesonde data constitute a mainstay of satellite calibration and are used for climatologies and analysis of trends, especially in the lower stratosphere where satellites are most uncertain. The electrochemical-concentration cell (ECC) ozonesonde has been deployed at ~100 stations worldwide since the 1960s, with changes over time in manufacture and procedures, including details of the cell chemical solution and data processing. As a consequence, there are biases among different stations and discontinuities in profile timeseries from individual site records. Since 1996 the Julich [Germany] Ozone Sonde Intercomparison Experiment (JOSIE) has periodically tested ozonesondes in a simulation chamber designated the World Calibration Centre for Ozonesondes by WMO. In October- November 2017 a JOSIE campaign evaluated the sondes and procedures used in SHADOZ (Southern Hemisphere Additional Ozonesondes), a 14-station tropical and subtropical network. A distinctive feature of the 2017 JOSIE was that the tests were conducted by operators from eight SHADOZ stations; Nairobi, Natal, Irene, Costa Rica, Paramaribo, Reunion, Hanoi, Kuala Lumpur. Experimental protocols and preliminary results for the SHADOZ sonde configurations, which represent most of those in use today, are described. SHADOZ stations that follow WMO-recommended protocols record total ozone within 3% of the JOSIE reference instrument. Instrument biases noted in prior JOSIE and field tests like BESOS (2004) were noted in JOSIE-2017, with maximum effect in the stratosphere. In June 2018 we organized a series of dual launches during the OWLETS II campaign in the Maryland and Chesapeake Bay area (SHALLOTS = SHADOZ-OWLETS ParaLLel Ozonesonde Test Study). Instrument and solution types were varied as in JOSIE-2017 and three radiosonde-ozonesonde variants were tested. An example of a parallel sampling in SHALLOTS, from a Greenbelt EnSCI-iMet sonde combination flown with the Wallops SPCLMS package, is illustrated in the Figure. The result was a range of biases but in general the instrument combination (EnSCI-iMet) deployed at 11 SHADOZ stations recorded ~5-10% less ozone in the stratosphere than the SPC ECC sonde flown with a Vaisala or LMS system. These 2017 and 2018 results and prior JOSIEs demonstrate that regular testing is essential to maintain best practices in ozonesonde operations and to ensure high-quality data for the ozone assessment communities.