Understanding how soil thickness and bedrock weathering vary across ridge and valley topography is needed to constrain the flowpaths of water and sediment production within a landscape. Here, we investigate saprolite and weathered bedrock properties across a ridge-valley system in the Northern California Coast Ranges, USA, where topography varies with slope aspect such that north facing slopes have thicker soils and are more densely vegetated than south facing slopes. We use active source seismic refraction surveys to extend observations made in boreholes to the hillslope scale. Seismic velocity models across several ridges capture a high velocity gradient zone (from 1000 to 2500 m/s) located ~4-13 m below ridgetops, that coincides with transitions in material strength and chemical depletion observed in boreholes. Comparing this transition depth across multiple north and south-facing slopes, we find that the thickness of saprolite does not vary with slope aspects. Additionally, seismic survey lines perpendicular and parallel to bedding planes reveal weathering profiles that thicken upslope and taper downslope to channels. Using a rock physics model incorporating seismic velocity, we estimate the total porosity of the saprolite and find that inherited fractures contribute a substantial amount of pore space in the upper 6 m, and the lateral porosity structure varies strongly with hillslope position. The aspect-independent weathering structure suggests the contemporary critical zone structure at Rancho Venada is a legacy of past climate and vegetation conditions.

Fault zone complexities contain important information about earthquake physics. High-resolution fault zone imaging requires high-quality data from dense arrays and new seismic imaging techniques that can utilize large portions of recorded waveforms. Recently, the emerging Distributed Acoustic Sensing (DAS) technique has enabled near-surface imaging by utilizing existing telecommunication infrastructure and anthropogenic noise sources. With dense sensors at several meters’ spacing, the unaliased wavefield can provide unprecedented details for fault zones. In this work, we use a DAS array converted from a 10-km underground fiber-optic cable across Ridgecrest City, California. We report clear spurious arrivals and coda waves in ambient noise cross-correlations caused by surface-to-surface wave scattering. We use these scattering-related waves to locate and characterize potential faults. The mapped fault locations are generally consistent with those in the USGS Quaternary Fault database of the United States but are more precise. We also use waveform modeling to infer that a 35-m wide, 90-m deep fault with 30% velocity reduction can best fit the observed scattered coda waves for one of the identified fault zones. These findings demonstrate the potential of DAS for passive imaging of fine-scale faults in an urban environment.

Klyuchevskoy and surrounding volcanoes in central Kamchatka form the Northern Group of Volcanoes (NGV), which is an area of the particularly diverse and intensive Pleistocene-Holocene volcanism. In this study, we present a new seismic tomographic model of the crust and uppermost mantle beneath NGV based on local earthquake data recorded by several permanent and temporary seismic networks including a large-scale KISS experiment that was conducted in 2015-2016 by an international scientific consortium. The new model has for Kamchatka an unprecedented resolution and reveals many features associated with the present and past volcanic activity within the NGV. In the upper crust, we found several prominent high-velocity anomalies interpreted as traces of large basaltic shield volcanoes, which were hidden by more recent volcanic structures and sediments. For the mantle structures, we found that the entire system of NGV was fed by an asthenospheric flow arriving through a slab window located below the Kamchatka-Aleutian junction. The interaction of the hot asthenospheric material with fluids released from the slab determines the particular volcanic activity within the NVG. We argue that the eastern branch of the Central Kamchatka Depression, which is associated with a prominent low-velocity anomaly in the uppermost mantle, was formed as a recent rift zone separating the NGV from the Kamchatka Eastern Ranges.

Improving nitrogen (N) status in European water bodies is a pressing issue. N levels depend not only on current but also past N inputs to the landscape, that have accumulated through time in legacy stores (e.g. soil, groundwater). Catchment-scale N models, that are commonly used to investigate in-stream N levels, rarely examine the magnitude and dynamics of legacy components. This study aims to gain a better understanding of the long-term fate of the N inputs and its uncertainties, using a legacy-driven N model (ELEMeNT) in Germany’s largest national river basin (Weser; 38,450 km2) over the period 1960-2015. We estimate the nine model parameters based on a progressive constraining strategy, to assess the value of different observational datasets. We demonstrate that beyond in-stream N loading, soil N content and in-stream N concentration allow to reduce the equifinality in model parameterizations. We find that more than 50% of the N surplus denitrifies (1480-2210 kg ha-1) and the stream export amounts to around 18% (410-640 kg ha-1), leaving behind as much as around 230-780 kg ha-1 of N in the (soil) source zone and 10-105 kg ha-1 in the subsurface. A sensitivity analysis reveals the importance of different factors affecting the residual uncertainties in simulated N legacies, namely hydrologic travel time, denitrification rates, a coefficient characterising the protection of organic N in source zone and N surplus input. Our study calls for proper consideration of uncertainties in N legacy characterization, and discusses possible avenues to further reduce the equifinality in water quality modelling.

In this study, we have developed a hyper-resolution land-surface forcing dataset (temperature, pressure, humidity, wind speed, incident longwave and shortwave radiation) from coarse resolution products using a physically-based downscaling approach. These downscaling techniques rely on correlations with landscape variables, such as topography, temperature lapse rate corrections, surface roughness and land cover. A proof-of-concept has been implemented over the Oklahoma domain, where high-resolution observations are available for validation purposes. The hourly NLDAS (North America Land Data Assimilation System) forcing data at 0.125° have been downscaled to 500m resolution over the study area during 2015. Results show that correlation coefficients between the downscaled forcing dataset and ground observations are consistently higher and biases are lower than the ones between the NLDAS forcing dataset at their native resolution and ground observations. Results are therefore encouraging as they demonstrate that the 500m forcing dataset has a good agreement with the ground information and can be adopted to force the land surface model for land state estimation. The Noah-MP land surface model is then forced with both the native resolution NLDAS dataset and the downscaled one to simulate surface and root zone soil moisture. Model outputs are compared with in situ soil moisture observations and SMAP (Soil Moisture Active Passive Mission) products at different spatial resolutions. This work will result in a radical improvement over the current state-of-the-art forcing data and will move into the era of hyper-resolution land modeling.

In order to determine particle velocities and electric field in the frame of the magnetic structure, one first needs to determine the velocity of the magnetic structure in the frame of the spacecraft observations. Here, we show how to determine a two dimensional magnetic structure velocity for the magnetic reconnection event observed in the magnetotail by the Magnetospheric Multiscale (MMS) spacecraft on 11 July 2017. We use two different multi-spacecraft methods, Spatio-Temporal Difference (STD) and the recently developed polynomial reconstruction method. Both of these methods use the magnetic field measurements, and the reconstruction technique also uses the current density measured by the particle instrument. We find rough agreement between the results of our methods and with other velocity determinations previously published. We also explain a number of features of STD and show that the polynomial reconstruction technique is only likely to be valid within a distance of two spacecraft spacings from the centroid of the MMS spacecraft. Both of these methods are susceptible to contamination by magnetometer calibration errors.

Based on a large database of Wideband Imaging Camera (WIC), which is a part of Far Ultraviolet (FUV) instrument, onboard the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) satellite during 5 years between 2000 and 2005, we found a new morphological type of transpolar arcs (TPAs), which are identified as “nightside distorted TPAs”. The nightside ends of the dawnside (duskside) TPAs got distorted toward pre- (post-) midnight sector; These TPAs look like the shape of an alphabetical letter of “J” or “L”. We identified 17 nightside distorted TPAs from our database. The 12 events out of 17 nightside distorted TPA events were the dawnside TPA with the nightside end distorted toward the pre-midnight sector (“J”-shaped TPA), and the TPAs in the duskside, whose nightside parts got distorted toward the post-midnight sector, were found in the remnant 5 events (“L”-shaped TPA). Statistically, the nightside distorted TPAs can dominantly be found under the northward Interplanetary Magnetic Field (IMF) conditions. Furthermore, when the IMF-By component pointed to the dawnward (duskward) direction, the “J” (“L”)-shaped TPAs were dominantly observed, suggesting that the relation between the IMF-Bz and By orientations, and the locations of the nightside distorted TPAs is consistent with that between the IMF conditions and regular TPA previously reported. We also followed the time sequence of the nightside distorted TPA evolution with the IMAGE FUV-WIC imager and additional Polar UVI data. In most cases, the “J” and “L”-shaped TPAs started to grow from the nightside main auroral oval, and protruded to the dayside region with being distorted. In this presentation, we will introduce several selected cases of the nightside distorted TPA among our database, and discuss why and how the nightside end of the TPA became distorted toward pre- or post-midnight sectors based on the in-situ satellite nightside plasma sheet observations and the electron drift velocity distribution calculated utilizing a simple electromagnetic field model in magnetotail, together with the auroral imager data.

The time scale of usual hydrological applications can vary from a few minutes to a few days. An accurate description of the precipitation probability distributions at the appropriate time scale is needed to compute meaningful summaries like return levels and periods. However few statistical parametric models can handle the full rainfall distribution at these different temporal scales. In this context, we propose and study a new meta-Gaussian model which leads to a parametric model with four parameters for the full distribution of precipitation. The main advantage of our model is that it can be applied to a wide range of accumulation periods. In particular, it still performs well below the hourly scale. In addition, each parameter is linked to a different part of the distribution: one of them describes the probability of rainfall occurrence, two parameters are related respectively to the shape of lower and upper tails of the distribution, and the last one is a multiplicative scale parameter. The building block of our model is the use of a latent Gaussian process that offers flexibility and simple inference algorithms. The model is fitted to rain gauge data recorded in Guipavas (France). It is shown that the proposed distribution handles accumulation periods from 6 minutes to several days. The model outperforms other meta-Gaussian models which have been proposed in the literature.

Tomographic analysis of Pn arrivals times—the guided P-wave propagating within the lithospheric mantle—is ideal for studying the structure of the uppermost mantle. While plate-scale seismic images of Pn wave speeds are common beneath the continents, similar scale studies have not been possible within ocean basins due to the sparsity of seismic stations. The Cascadia Initiative (CI) dataset provides the first opportunity to image spatial variations in lithospheric structure across an entire oceanic plate. We measure 2,862 Pn arrivals from local earthquakes recorded by the CI array. Our dataset provides complete coverage of both the Juan de Fuca (JdF) and deforming Gorda plates. We invert the measured arrival times for 3D variations in anisotropic P-wave velocity and hypocentral parameters. Despite surficial evidence of extensive active faulting, the velocity structure of the Gorda uppermost mantle is remarkably consistent with predictions from a conductive cooling model (attached figure). Limited deformation at mantle depths is supported by seismic anisotropy measurements that show the fast-direction of P-wave propagation rotates in concert with the magnetic anomaly lineations. This rotation may be explained by local plate kinematics without internal deformation and hydration of the shallow mantle. In contrast to Gorda, the seismic velocity structure of the JdF plate does not exhibit a clear age dependence. Three pronounced mantle low-velocity zones are found along the southern edge of the JdF plate near the termini of large pseudofaults that contributed to the formation of the Blanco Transform fault. We attribute these velocity reductions to mantle alteration by seawater. We note that within the interior of the JdF plate pseudofaults do not appear as uniformly slow features in our seismic images. Beneath the central and northern JdF plate, P-wave speeds are ~7.7 km/s out to ~4-5 Myr before abruptly increasing to ~7.9 km/s. Curiously, this transition occurs near the onset of mantle downwelling inferred from teleseismic body wave tomography and attenuation suggesting that mantle flow dynamics may influence the structure of young oceanic lithosphere. Lastly, we note that our results do not suggest a relationship between the structure of the uppermost slab mantle and segmentation of the Cascadia megathrust.

Quantification of heat and constituent transport by gravity waves in global models is challenging due to limited model resolutions. Current parameterization schemes suffer from over-simplification and often underestimate the transport rate. In this study, a new approach is explored to quantify the effective vertical eddy diffusion by using a high-resolution WACCM simulation based on scale invariance. The WACCM simulation can partially resolve the mesoscale gravity wave spectrum down to ~250 km horizontal wavelength, and the heat flux and the effective vertical eddy diffusion by these waves are calculated directly. The effective vertical diffusion by the smaller-scale, unresolved waves, is then deduced based on scale invariance, following the method outlined by Liu (2019) in quantifying gravity wave momentum flux and forcing. The effective vertical diffusion obtained is generally larger than that obtained from parameterizations, and is comparable with that derived from observations in the mesosphere and lower thermosphere region.

Detrital zircon records of provenance are used to reconstruct paleogeography, sediment sources, and tectonic configuration. Recognition of the biases in detrital zircon records that result from hydraulic sorting of sediment and the initial characteristics of zircons in source regions (e.g., size and abundance) has added new complexity and caution in the interpretation of these records. In this study, we examine the role of transport process and sediment sorting in these records. We begin our analysis by investigating the influence of grain size and transport process in biasing detrital zircon provenance records in an idealized sedimentary system. Our modeling results show that settling and selective entrainment can leave distinct, process-dependent fingerprints in detrital zircon spectra if initial size variation between source zircon populations exists. We then consider a case study: a detrital zircon record from Ediacaran to Terreneuvian Death Valley. We focus on the Rainstorm Member, which is geochemically, mineralogically, and sedimentologically unusual. In addition to Earth’s largest negative carbon isotope excursion (the Shuram excursion), the Rainstorm Member also contains anachronistic carbonate structures and a detrital mineral suite enriched in heavy minerals. We evaluate the detrital zircon provenance record of the Rainstorm Member, and find that, despite its unusual character, the provenance of the unit is similar to other units in the succession, with substantial input from Yavapai-Matzatzal provinces. Size and density measurements of heavy and light density components of the deposit suggest that its enriched heavy mineral suite is best explained through concentration by selective entrainment and winnowing. We find that our detrital zircon dataset is susceptible to hydrodynamic fractionation, so that grain size exerts influence on its provenance record, in particular for large Grenville-aged (1.0-1.2 Ga) grains.

We present evidence of volcano-tectonic interactions at Sabancaya volcano that we relate to episodic magma injection and high regional fluid pore pressures. We present a surface deformation time series at Sabancaya including observations from ERS-1/2, Envisat, Sentinel-1, COSMO-SkyMed, and TerraSAR-X that spans June 1992 - February 2019. These data show deep seated inflation northwest of Sabancaya from 1992-1997 and 2013-2019, as well as creep and rupture on multiple faults. Afterslip on the Mojopampa fault following a 2013 Mw 5.9 earthquake is anomalously long-lived, continuing for at least six years. The best fit fault plane for the afterslip is right-lateral motion on an EW striking fault at 1 km depth. We also model surface deformation from two 2017 earthquakes (Mw 4.4 and Mw 5.2) on unnamed faults, for which the best fit models are NW striking normal faults at 1-2 km depth. Our best fit model for a magmatic inflation source (13 km depth, volume change of 0.04 to 0.05 km^3 yr^-1), induces positive Coulomb static stress changes on these modeled fault planes. Comparing these deformation results with evidence from satellite thermal and degassing data, field observations, and seismic records, we interpret strong pre-eruptive seismicity at Sabancaya as a consequence of magmatic intrusions destabilizing tectonic faults critically stressed by regionally high fluid pressures. High fluid pressure likely also promotes fault creep driven by static stress transfer from the inflation source. We speculate that strong seismicity near volcanoes will be most likely with high pore fluid pressures and significant, offset magmatic inflation.

To obtain phenotypic parameters by means of lossy measurement, we proposed a comprehensive and integrated approach to predict different parameters of four varieties of lettuces. By building different prediction models, we required predicted value of five phenotypic parameters of lettuce. Test results indicate that prediction models we have constructed are reliable and feasible. In addition,our methods can be better transferred to the research of other crops, and producers can adjust the growing environment of crops in time, so as to obtain higher yield.

Determining paleotemperatures in terrestrial environments are much more challenging than those in the ocean because of stratigraphic inconsistencies, strong spatial and temporal variations in temperature, and a paucity of well-tested methods. Here we utilize the ganoine scales of gars from the family Lepisosteidae to calibrate a new terrestrial paleothermometer. Gars are widespread both in the modern and in the past, as they are a freshwater fish lineage that extends back into the Cretaceous (100 Ma) and have remained relatively unchanged during that time span. Gars constantly record water temperatures, whose yearly average is closely related to mean annual temperature, in their body tissues, including scales. These scales grow continuously throughout life, are >95% hydroxyapatite and thus are highly resistant to diagenetic alteration. Oxygen isotopes in both biogenic phosphates and carbonates have been used to reconstruct environments on land with varying degrees of success. Phosphate-oxygen isotopes are more resistant to post-mortem alteration as the phosphorus-oxygen bond is stronger than the carbon-oxygen bond. We investigate the application of phosphate oxygen isotopes to gar scales by collecting scales from modern individuals from a north-south transect across the United States, exploiting the latitudinal temperature gradient in mean annual temperatures, measuring δ18Ophosphate of those scales, and comparing these values to the average δ18Owater and temperature of each locality. We compare our δ18Ophosphate calibration to previously published curves. Our work demonstrates that the δ18Ophosphate values of gar scales are robust recorders of temperature and δ18Owater.

Geophysical granular flows exert basal forces that generate seismic signals, which can be used to better monitor and model these severe natural hazards. A number of empirical relations and existing models link these signals’ high-frequency components to a variety of flow properties, many of which are inaccessible by other analyses. However, the range of validity of the empirical relations remains unclear and the models lack validation, owing to the difficulty of adequately controlling and instrumenting field-scale flows. Here, we present laboratory experiments investigating the normal forces exerted on a basal plate by dense and partially dense flows of spherical glass particles. We measured the power spectra of these forces and inferred predictions for these power spectra from the models for debris flows’ seismic signals proposed by Kean et al. (2015), Lai et al. (2018), and Farin, Tsai, et al. (2019), using Hertz theory to extend Farin, Tsai, et al. (2019)’s models to higher frequencies. Comparison of our bservations to these predictions, and to predictions derived from Bachelet (2018) and Bachelet et al. (2021)’s model for granular flows’ seismic signals, shows those of Farin, Tsai, et al. (2019)’s ‘thin-flow’ model to be the most accurate, so we examine explanations for this accuracy and discuss its implications for geophysical flows’ seismic signals. We also consider the normalisation, by the mean force exerted by each flow, of the force’s mean squared fluctuations, showing that this ratio varies by four orders of magnitude over our experiments, but is determined by the bulk inertial number of the flow.

In this paper we analyze the effect of material coherence on the transport properties of 9 eddies sampled during research cruises. We check the accuracy of our data and, after reviewing different definitions of coherence, we assess whether these eddies have retained a heterogeneous water mass in their cores. T, S anomalies on isopycnal surfaces are computed to highlight the different thermohaline properties between the eddy core and its surroundings. The maximum of the tracer anomaly is often located below the pycnocline. We find that while some of these eddies are not coherent according to surface data only, they are when their entire 3D structure is considered. We then present two methods for extrapolating eddy volumes from a single hydrographic section. The volume obtained from T,S anomalies on isopycnical surfaces is compared with that obtained by other criteria. Our results show that the outermost closed contour of the Brunt-Väisäla frequency is a good approximation for the eddy boundary when calculating its volume.

We introduce and evaluate an approach for the simultaneous retrieval of aerosol and surface properties from Airborne Visible/Infrared Imaging Spectrometer Classic (AVIRIS-C) data collected during wildfires. The joint National Aeronautics and Space Administration/National Oceanic and Atmospheric Administration (NASA/NOAA) Fire Influence on Regional to Global Environments and Air Quality (FIREX-AQ) field campaign took place in August 2019, and involved two aircraft and coordinated ground-based observations. The AVIRIS-C instrument acquired data from onboard NASA’s high altitude ER-2 research aircraft, coincident in space and time with aerosol observations obtained from the Aerosol Robotic Network (AERONET) DRAGON mobile platform in the smoke plume downwind of the Williams Flats Fire in northern Washington in August, 2019. Observations in this smoke plume were used to assess the capacity of optimal-estimation based retrievals to simultaneously estimate aerosol optical depth (AOD) and surface reflectance from Visible Shortwave Infrared (VSWIR) imaging spectroscopy. Radiative transfer modeling of the sensitivities in spectral information collected over smoke reveal the potential capacity of high spectral resolution retrievals to distinguish between sulfate and smoke aerosol models, as well as sensitivity to the aerosol size distribution. Comparison with ground-based AERONET observations demonstrates that AVIRIS-C retrievals of AOD compare favorably with direct sun AOD measurements. Our analyses suggest that spectral information collected from the full VSWIR spectral interval, not just the shortest wavelengths, enables accurate retrievals. We use this approach to continuously map both aerosols and surface reflectance at high spatial resolution across heterogeneous terrain, even under relatively high AOD conditions associated with wildfire smoke.

The original Evaporometer prototype was designed by the Openly Published Environmental Sensing (OPEnS) Lab at Oregon State University to remotely collect near real-time environmental data, including temperature, humidity, luminosity, and amount of precipitation, and transmit it to a receiver hub, where it can be viewed online by researchers worldwide. This eliminates costly and time-consuming site visits. Deployed during the summer of 2017 in OSU’s HJ Andrew’s Experimental Forest, the prototype failed after three months due to excess moisture entering the enclosure and damaging the hardware. Over its first two months, the prototype performed well, gathered over 90,000 data points, updating every five minutes. To extend the lifespan of the Evaporometer, the enclosure was redesigned to improve weatherproofing, include additional sensors, and improve the accuracy of data readings. These improvements will extend the Evaporometer’s field life, allowing it to reliably gather and transmit data for longer periods of time while the ability to gather albedo measurement expands the device’s sensing capabilities. The upgraded Evaporometer provides researchers with a reliable, low-cost, and open-sourced method of collecting environmental data in locations that may not have previously been feasible.