Preprints
There are 6976 Preprints listed.
Closing the gap: Explaining persistent underestimation by US oil and natural gas production-segment methane inventories
Published: 2020-11-03
Subjects: Environmental Indicators and Impact Assessment, Oil, Gas, and Energy
Methane (CH4) emissions from oil and natural gas (O&NG) systems are an important contributor to greenhouse gas emissions. In the United States, recent synthesis studies of field measurements of CH4 emissions at different spatial scales are ~1.5x-2x greater compared to official greenhouse gas inventory (GHGI) estimates, with the production-segment as the dominant contributor to this divergence. [...]
A single multi-scale and multi-sourced semi-automated lineament detection technique for detailed structural mapping with applications to geothermal energy exploration
Published: 2020-10-22
Subjects: Geology, Geomorphology, Tectonics and Structure
A multitude of semi-automated algorithms, many incorporating multi-sourced datasets into a single analysis, now exist. However, these operate at a fixed pixel resolution resulting in multi-sourced methods being limited by the largest input pixel size. Multi-scale lineament detection circumvents this issue and allows increased levels of detail to be captured. In this study we present a [...]
Morphodynamic modelling of beach cusp formation: the role of wave forcing and sediment composition
Published: 2020-10-29
Subjects: Physical Sciences and Mathematics
A field of beach cusps formed during a field experiment at Nha Trang Beach, Vietnam, under accretive conditions. The measured data was used to set-up morphodynamic simulations in XBeach, which was able to simulate cusp formation from an initially long-shore uniform beach profile. Several types of simulations were run in order to observe the resulting variation in mean cusp dimensions (length, [...]
A comprehensive study to understand the relationship of urbanization and population density with GRACE ΔTWS for selected study regions in India during 2003-2017
Published: 2020-10-24
Subjects: Environmental Indicators and Impact Assessment, Hydrology, Natural Resources and Conservation, Natural Resources Management and Policy, Planetary Hydrology, Remote Sensing, Sustainability, Water Resource Management
This work investigates the relationship between urbanization, population density and meteorological variables (temperature & precipitation) on groundwater storage in India during the period January'2003 to January'2017. Variations in groundwater storage have been analysed using Gravity Recovery and Climate Experiment (GRACE) derived variations of Terrestrial Water Storage (TWS). In the first part [...]
The Emergent Influence of Anthropogenic Warming on Global Crop Yields
Published: 2020-10-30
Subjects: Atmospheric Sciences, Climate, Environmental Sciences, Social and Behavioral Sciences, Statistical Methodology
A large literature on “detection and attribution” has now demonstrated the influence of anthropogenic greenhouse gas emissions on a range of physical climate variables. Social and economic outcomes are known to be sensitive to climate change, but directly connecting observed changes to anthropogenic forcing is challenging. Here I estimate the effect of anthropogenic warming on global crop yield [...]
Assimilation of GNSS Reflectometry Delay-Doppler Maps into Global Ocean Surface Wind Analyses
Published: 2020-10-26
Subjects: Earth Sciences
Direct remote sensing observations (e.g. radar backscatter, radiometer brightness temperature, or radio occultation bending angle) are often more effective for use in data assimilation (DA) than the corresponding geophysical retrievals (e.g. ocean surface winds, soil moisture, or atmospheric water vapor). In the particular case of Global Navigation Satellite System Reflectometry (GNSS-R), the [...]
Salt-magma interactions influence intrusion distribution and salt tectonics in the Santos Basin, offshore Brazil
Published: 2020-10-25
Subjects: Earth Sciences, Geology, Tectonics and Structure, Volcanology
Many sedimentary basins host thick evaporite (salt) deposits. Some of these basins also host extensive igneous intrusion networks. It thus seems inevitable that, in some locations, magma will interact with salt. Yet how interaction between these materials may influence salt tectonics or magma emplacement, particularly at the basin-scale, remains poorly understood. We use 3D seismic reflection [...]
Using Machine-Learning Models for Field-Scale Crop Yield and Condition Modeling in Argentina
Published: 2020-11-09
Subjects: Environmental Studies, Geographic Information Sciences, Remote Sensing, Spatial Science
Accurately determining crop growth progress and crop yields at field-scale can help farmers estimate their net profit, enable insurance compa-nies to ascertain payouts, and help in ensuring food security. At field scales, the troika of management, soil and weather combine to impact crop growth pro-gress, and this progress can be monitored in-season using satellite data. Here, we use satellite [...]
Optimizing Crop Cut Collection for Determining Field-Scale Yields in an Insurance Context
Published: 2020-11-10
Subjects: Geographic Information Sciences, Geography, Other Engineering, Remote Sensing, Spatial Science
Accurately determining crop yields at field-scale can help farmers estimate their net profit, enable insurance companies to ascertain payouts, and when aggregated at regional and national scales, crop yield estimates are critical in ensuring food security. Over the last few decades, crop cuts have been widely used to estimate field-scale crop yields. Crop cuts, while cost prohibitive, are the [...]
Impacts of a regional multi-year insect defoliation event on seasonal runoff ratios and instantaneous streamflow characteristics
Published: 2020-10-26
Subjects: Forest Sciences, Hydrology, Terrestrial and Aquatic Ecology, Water Resource Management
Repeated moderate severity forest disturbances can cause short- and long-term shifts in ecosystem processes. Prior work has found that stand-replacing disturbances (e.g., clear-cutting) increases streamflow in temperate forests, but streamflow responses to repeated moderate severity disturbances are more equivocal. This study examined a moderate disturbance caused by an unexpected population [...]
The large-scale troughs on Asteroid 4 Vesta accommodate opening-mode displacement
Published: 2020-10-27
Subjects: Physical Sciences and Mathematics
The Dawn mission at Asteroid 4 Vesta revealed two sets of enormous linear structures. Both sets are troughs—linear, negative-relief landforms—with one spanning around two-thirds of the equator and the other set located in the northern hemisphere. Previous work evaluated the shapes of the troughs and interpreted them to be analogous to grabens, which are landforms caused by faulting; however, an [...]
Responses of tropical marine ecosystems to climate change impacts and their treatment in biogeochemical ecosystem models
Published: 2020-10-27
Subjects: Life Sciences, Physical Sciences and Mathematics
To predict the effects of climate change on marine ecosystems and the effectiveness of intervention and mitigation strategies, we need reliable marine ecosystem response models such as biogeochemical models that reproduce climate change effects. We reviewed marine ecosystem parameters and processes that are modified by climate change and examined their representations in biogeochemical ecosystem [...]
Studying the initiation of volcanic eruptions: Time for a petrological perspective.
Published: 2020-10-28
Subjects: Earth Sciences, Volcanology
Volcano monitoring is essential for mitigating the risks associated with volcanic activity. As monitoring becomes more sophisticated and widespread, there is a growing need for understanding the relationship between different monitoring records and magmatic processes occurring at depth. This is particularly relevant to the processes that initiate eruptions after the extended periods of repose and [...]
High-frequency global wavefields for local 3D structures by wavefield injection and extrapolation
Published: 2020-10-28
Subjects: Geophysics and Seismology
Earth structure is multiscale, and seismology remains the primary means of deciphering signatures from small structures over large distances. To enable this at the highest resolution, we present a flexible injection and extrapolation type hybrid framework that couples wavefields from a precomputed global database of accurate Green’s functions with a local three dimensional (3-D) method of [...]
Urban Air Quality Modeling Using Low-Cost Sensor Network and Data Assimilation in the Aburra Valley, Colombia
Published: 2020-10-29
Subjects: Applied Mathematics, Atmospheric Sciences, Environmental Monitoring
The use of low air quality networks has been increasing in recent years to study urban pollution dynamics. Here we show the evaluation of the operational Aburra Valley's low-cost network against the official monitoring network. The results show that the PM2.5 low-cost measurements are very close to those observed by the official network. Additionally, the low-cost allows a higher spatial [...]