Preprints
Filtering by Subject: Physical Sciences and Mathematics
CO2 capture by pumping surface acidity to the deep ocean
Published: 2021-04-30
Subjects: Chemical Engineering, Climate, Engineering, Environmental Engineering, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The majority of IPCC scenarios call for active CO2 removal (CDR) to remain below 2oC of warm- ing. On geological timescales, ocean uptake regulates atmospheric CO2 concentration, with two homeostats driving CO2 uptake: dissolution of deep ocean calcite deposits and terrestrial weathering of silicate rocks, acting on 1ka to 100ka timescales, respectively. Many current ocean-based CDR proposals [...]
Use of environmental tracers (tritium3H and SF6) to improve knowledge of aquifer storage capacity, residence time and sustainability in the crystalline rock island aquifer of Tobago, West Indies.
Published: 2021-04-29
Subjects: Physical Sciences and Mathematics
Understanding the residence time, flow velocities and storage volumes in fractured rock aquifers is essential for assessing the sustainable use of groundwater in island aquifer systems. Environmental tracers such as tritium (3H) and sulfur hexafluoride (SF6) that enter the aquifer systems through natural hydrological processes are effectively used to quantify the “apparent age” of young [...]
Expert judgements on solar geoengineering research priorities and challenges
Published: 2021-04-29
Subjects: Physical Sciences and Mathematics, Social and Behavioral Sciences
Solar geoengineering describes a set of proposals to deliberately alter the earth’s radiative balance to reduce climate risks. We elicit judgements on natural science research priorities for solar geoengineering through a survey and in-person discussion with 72 subject matter experts, including two thirds of all scientists with ≥10 publications on the topic. Experts prioritized Earth system [...]
Probing the nucleation of iron in Earth’s core using MD simulations of supercooled liquids
Published: 2021-04-29
Subjects: Earth Sciences, Physical Sciences and Mathematics
Classical nucleation theory describes the formation of the first solids from supercooled liquids and predicts an average waiting time for a system to freeze as it is supercooled to temperatures below the melting temperature. For systems at low to moderate undercooling, waiting times are too long for freezing to be observed via experiment or simulation. Here a system can be described by estimated [...]
Evapotranspiration and energy partitioning across a forest-shrub vegetation gradient in a subarctic, alpine catchment
Published: 2021-04-27
Subjects: Physical Sciences and Mathematics
As a result of altitude and latitude amplified climate change, widespread changes in vegetation composition, density and distribution have been observed across northern regions. Despite wide documentation of shrub proliferation and treeline advance, few field-based studies have evaluated the hydrological implications of these changes. Quantification of total evapotranspiration (ET) across a range [...]
Utilizing Random Forest Machine Learning Models to Determine Water Table Flood Levels through Volunteered Geospatial Information
Published: 2021-04-27
Subjects: Applied Mathematics, Computer Sciences, Earth Sciences, Environmental Sciences, Physical Sciences and Mathematics
Many people use smartphone cameras to record their living environments through captured images, and share aspects of their daily lives on social networks, such as Facebook, Instagram, and Twitter. These platforms provide volunteered geographic information (VGI), which enables the public to know where and when events occur. At the same time, image-based VGI can also indicate environmental changes [...]
Six simple steps towards making GEES fieldwork more accessible and inclusive
Published: 2021-04-26
Subjects: Education, Physical Sciences and Mathematics
Fieldwork is a defining aspect of Physical Geography, Earth and Environmental Science programme curricula. At its best, fieldwork offers students valuable opportunities to develop independent research skills in real-world situations, examine analogues for a range of scientific concepts, and socialise with peers. It offers experiences that are challenging to replicate using virtual/remote [...]
Note on the bulk estimate of the energy dissipation rate in the oceanic bottom boundary layer
Published: 2021-04-26
Subjects: Oceanography, Physical Sciences and Mathematics
The dissipation of the kinetic energy (KE) associated with oceanic flows is believed to occur primarily in the oceanic bottom boundary layer (BBL) where bottom drag converts the KE from mean flows to heat loss through irreversible mixing at molecular scales. Due to the practical difficulties associated with direct observations on small-scale turbulence close to the seafloor, most up-to-date [...]
Timing of iceberg scours and massive ice-rafting events in the subtropical North Atlantic
Published: 2021-04-26
Subjects: Physical Sciences and Mathematics
High resolution seafloor mapping shows extraordinary evidence that massive (>300m thick) icebergs once drifted >5,000km south along the eastern United States, with over 700 iceberg scours now identified south of Cape Hatteras. Sediment cores collected from several buried scours show multiple plow marks are ~31,000 years old and align with Heinrich Event 3 (H3). An accompanying set of numerical [...]
Optimal experiment design for bottom friction parameter estimation
Published: 2021-04-23
Subjects: Design of Experiments and Sample Surveys, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
It is common practice within numerical coastal ocean modelling to perform model calibration with respect to a bottom friction parameter. While many modelling studies employ a spatially uniform coefficient, within the parameter estimation literature the coefficient is typically taken to be spatially (or even temporally) varying. A parameter estimation experiment requires an appropriate set of [...]
Experimental Determination of Mantle Solidi and Melt Compositions for Two Likely Rocky Exoplanet Compositions
Published: 2021-04-22
Subjects: Physical Sciences and Mathematics
For rocky exoplanets, knowledge of their geologic characteristics such as composition and mineralogy, surface recycling mechanisms, and volcanic behavior are key to determining their suitability to host life. Thus, determining exoplanet habitability requires an understanding of surface chemistry, and understanding the composition of exoplanet surfaces necessitates applying methods from the field [...]
Bridging Spatiotemporal Scales of Normal Fault Growth During Continental Extension Using High-Resolution 3D Numerical Models
Published: 2021-04-21
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Other Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
Continental extension is accommodated by the development of kilometre-scale normal faults, which grow during metre-scale slip events that occur over millions of years. However, reconstructing the entire lifespan of a fault remains challenging due to a lack of observational data with spatiotemporal scales that span the early stage (<10^6 yrs) of fault growth. Using 3D numerical simulations of [...]
Decadal Evaluation of the AIRPACT Regional Air Quality Forecast System in the Pacific Northwest from 2009-2018
Published: 2021-04-21
Subjects: Engineering, Physical Sciences and Mathematics
The Air Indicator Report for Public Awareness and Community Tracking (AIRPACT) is a comprehensive, automated air quality forecast system that provides 48-hr in-advance air quality over the Pacific Northwest region (http://lar.wsu.edu/airpact/). Since 2001, the AIRPACT forecasting system has been successfully operated by Washington State University, with the financial support from the Northwest [...]
Poleward shift in the Southern Hemisphere westerly winds synchronous with the deglacial rise in CO2
Published: 2021-04-21
Subjects: Physical Sciences and Mathematics
The Southern Hemisphere westerly winds influence deep ocean circulation and carbon storage. While the westerlies are hypothesised to play a key role in regulating atmospheric CO2 over glacial-interglacial cycles, past changes in their position and strength remain poorly constrained. Here, we use a compilation of planktic foraminiferal delta-18O from across the Southern Ocean and emergent [...]
The stabilizing effect of high pore-fluid pressure along subduction megathrust faults: Evidence from friction experiments on accretionary sediments from the Nankai Trough
Published: 2021-04-21
Subjects: Physical Sciences and Mathematics
Pore-fluid pressure is an important parameter in controlling fault mechanics as it lowers the effective normal stress, allowing fault slip at lower shear stress. It is also thought to influence the nature of fault slip, particularly in subduction zones where areas of slow slip have been linked to regions of elevated pore-fluid pressure. Despite the importance of pore-fluid pressure on fault [...]