Preprints
There are 4721 Preprints listed.
Copper availability governs nitrous oxide accumulation in wetland soils and stream sediments
Published: 2021-12-15
Subjects: Biogeochemistry, Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Engineering, Geochemistry, Life Sciences
Denitrification is microbially-mediated through enzymes containing metal cofactors. Laboratory studies of pure cultures have highlighted that the availability of Cu, required for the multicopper enzyme nitrous oxide reductase, can limit N2O reduction. However, in natural aquatic systems, such as wetlands and hyporheic zones in stream beds, the role of Cu in controlling denitrification remains [...]
Challenges and uncertainty in plot-scale emissivity and surface temperature estimation using flux tower measurements
Published: 2021-12-15
Subjects: Physical Sciences and Mathematics
Land surface temperature (LST) is a preeminent state variable that controls the energy and water exchange between the Earth’s surface and the atmosphere. At the landscape-scale, LST is derived from thermal infrared radiance measured using space-borne radiometers. At the plot-scale, the flux tower recorded longwave radiation components are inverted to retrieve LST. Since the down-welling longwave [...]
Global trends in novel stable isotopes in basalts: theory and observations
Published: 2021-12-14
Subjects: Physical Sciences and Mathematics
The geochemistry of global mantle melts suggests that both mid-ocean ridge basalts (MORB) and ocean island basalts (OIB) sample lithological and temperature heterogeneities originating in both the upper and lower mantle. Recently, non-traditional stable isotopes have been suggested as a new tool to complement existing tracers of mantle heterogeneity (e.g., major and trace elements, radiogenic [...]
Filtering ground noise from LiDAR returns produces inferior models of forest aboveground biomass in heterogenous landscapes
Published: 2021-12-14
Subjects: Environmental Monitoring, Environmental Sciences, Forest Sciences, Research Methods in Life Sciences
Airborne LiDAR has become an essential data source for large-scale, high-resolution modeling of forest aboveground biomass and carbon stocks, enabling predictions with much higher resolution and accuracy than can be achieved using optical imagery alone. Ground noise filtering – that is, excluding returns from LiDAR point clouds based on simple height thresholds – is a common practice meant to [...]
A continuous vertically resolved ozone dataset from the fusion of chemistry climate models with observations using a Bayesian neural network
Published: 2021-12-14
Subjects: Atmospheric Sciences
Continuous historic datasets of vertically resolved stratospheric ozone, support the case for ozone recovery, are necessary for the running of offline models and increase understanding of the impacts of ozone on the wider atmospheric system. Vertically resolved ozone datasets are typically constructed from multiple satellite, sonde and ground-based measurements that do not provide continuous [...]
Adaptive Mesh Refinement Strategies for a Novel Modelof Immiscible Fluid Flow in Fractures
Published: 2021-12-13
Subjects: Civil and Environmental Engineering, Computational Engineering, Engineering
In this paper, we consider two Adaptive Mesh Refinement (AMR) methods to simulate flow through fractures using a novel multiphase model. The approach represents the fluid using a two-dimensional parallel-plate model that employs techniques adapted from lattice-Boltzmann simulations to track the fluid interface. Here, we discuss different mesh refinement strategies for the model and compare [...]
Thermochemical structure and evolution of cratonic lithosphere in central and southern Africa
Published: 2021-12-10
Subjects: Earth Sciences, Geochemistry, Geophysics and Seismology, Mineral Physics, Physical Sciences and Mathematics, Tectonics and Structure
The thermochemical structure of the subcontinental mantle holds information on its origin and evolution that can inform energy and mineral exploration strategies, natural hazard mitigation and evolutionary models of the Earth. However, imaging the fine-scale thermochemical structure of continental lithosphere remains a major challenge. Here we combine multiple land and satellite datasets via [...]
Elevated Post K-Pg Export Productivity in the Gulf of Mexico and Caribbean
Published: 2021-12-10
Subjects: Earth Sciences, Geochemistry, Paleobiology, Paleontology, Physical Sciences and Mathematics
The global heterogeneity in export productivity after the Cretaceous-Paleogene (K-Pg) mass extinction is well documented, with some sites showing no change on geologic timescales, some demonstrating sustained decline, and a few showing a somewhat surprising increase. However, observational data come from sites so widespread that a key outstanding question is the geographic scale of changes in [...]
Multi-proxy assessment of surface sediments using APPI-P FTICR-MS reveals a complex biogeochemical record along a salinity gradient in the Pearl River estuary and coastal South China Sea
Published: 2021-12-10
Subjects: Analytical Chemistry, Biogeochemistry, Chemistry, Earth Sciences, Environmental Chemistry, Environmental Monitoring, Environmental Sciences, Geochemistry, Physical Sciences and Mathematics
The Pearl River drains the second largest watershed in China, funnelling large amounts of freshwater and organic matter into the northern part of the South China Sea through an estuary characterized by pronounced biogeochemical gradients. In this study we analyzed organic extracts of surface sediments collected along land-sea transect that captures a transition from freshwater environment at the [...]
Large-Scale Controlled Experiment Demonstrates Effectiveness of Methane Leak Detection and Repair Programs at Oil and Gas Facilities
Published: 2021-12-09
Subjects: Earth Sciences, Environmental Sciences
The importance of reducing methane emissions from oil and gas operations as a near-term climate action is widely recognized. Most jurisdictions around the globe using leak detection and repair (LDAR) programs to find and fix methane leaks. In this work, we empirically evaluate the efficacy of LDAR programs using a large-scale, bottom-up, randomized controlled field experiment across ~200 oil and [...]
Components and Tidal Modulation of the Wave Field in a Semi-Enclosed Shallow Bay
Published: 2021-12-09
Subjects: Environmental Engineering, Geomorphology, Oceanography
The wave field in coastal bays is comprised of waves generated by far-off storms and waves generated locally by winds inside the bay and regionally outside the bay. The resultant wave field varies spatially and temporally and is expected to control morphologic features, such as beaches in estuaries and bays (BEBs). However, neither the wave field nor the role of waves in shaping BEBs have been [...]
Catchment vegetation and erosion controls soil carbon cycling in south-eastern Australia during the last two Glacial-Interglacial cycles
Published: 2021-12-09
Subjects: Earth Sciences, Geochemistry, Geomorphology, Sedimentology
External surface water influence on explosive eruption dynamics, with implications for stratospheric sulfur delivery and volcano-climate feedback
Published: 2021-12-09
Subjects: Fluid Dynamics, Geophysics and Seismology, Volcanology
Explosive volcanic eruptions can inject sulfur dioxide (SO2) into the stratosphere to form aerosol particles that modify Earth’s radiation balance and drive surface cooling. Eruptions involving interactions with shallow layers (< 500 m) of surface water and ice modify the eruption dynamics that govern the delivery of SO2 to the stratosphere. External surface water potentially controls the [...]
Wildfire Smoke Exposure Worsens Learning Outcomes
Published: 2021-12-08
Subjects: Environmental Public Health, Environmental Sciences, Environmental Studies, Statistical Models
Wildfires have increased in frequency and severity over the past two decades, threatening to undo substantial air quality improvements. We investigate the effect of wildfire smoke exposure on learning outcomes across the US using standardized test scores from 2009-2016 for nearly 11,700 school districts and satellite-derived estimates of daily smoke exposure. Relative to a school year with no [...]
Deep Coseismic Slip in the Cascadia Megathrust can be Consistent with Coastal Subsidence
Published: 2021-12-08
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
At subduction zones, the down-dip limit of slip represents how deep an earthquake can rupture. For hazards it is important - it controls the intensity of shaking and the pattern of coseismic uplift and subsidence. In the Cascadia Subduction Zone, because no large magnitude events have been observed in instrumental times, the limit is inferred from geological estimates of coastal subsidence during [...]