Preprints
Filtering by Subject: Physical Sciences and Mathematics
Quantifying the impact of lagged hydrological responses on the effectiveness of groundwater conservation
Published: 2021-05-27
Subjects: Earth Sciences, Hydrology, Physical Sciences and Mathematics
Many irrigated agricultural areas seek to prolong the lifetime of their groundwater resources by reducing pumping. However, it is unclear how lagged responses, such as reduced groundwater recharge caused by more efficient irrigation, may impact the long-term effectiveness of conservation initiatives. Here, we use a variably saturated, simplified surrogate groundwater model to: 1) analyze aquifer [...]
Detection of Interannual Ensemble Forecast Signals over the North Atlantic and Europe using Atmospheric Circulation Regimes
Published: 2021-05-27
Subjects: Applied Mathematics, Atmospheric Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
To study the forced variability of atmospheric circulation regimes, the use of model ensembles is often necessary for identifying statistically significant signals as the observed data constitute a small sample and are thus strongly affected by the noise associated with sampling uncertainty. However, the regime representation is itself affected by noise within the atmosphere, which can make it [...]
Uncertainty analysis in machine learning for lithofacies classification and porosity prediction
Published: 2021-05-27
Subjects: Engineering, Physical Sciences and Mathematics
Recently, machine learning has been widely and successfully used by geoscientists to solve typical inverse problems. However, the uncertainty related to the learned model is not properly analysed, and sometimes a simple activation function is applied to provide posterior probability. To address this problem, variance of machine learning models is calculated that can provide additional information [...]
Defining a Sustainable Development Target Space for 2030 and 2050
Published: 2021-05-24
Subjects: Environmental Indicators and Impact Assessment, Environmental Monitoring, Environmental Sciences, Environmental Studies, Natural Resource Economics, Other Environmental Sciences, Physical Sciences and Mathematics, Social and Behavioral Sciences, Sustainability
By adopting the Sustainable Development Goals (SDGs), countries worldwide agreed to an agenda for achieving a prosperous, socially inclusive and environmentally sustainable future for all1. This ambition, however, also exposes a critical knowledge gap since science-based insights on how to achieve the 17 SDGs simultaneously are lacking. Quantitative goal-seeking scenario studies could enable [...]
Modelled Soil Temperature Sensitivity to Variable Snow and Vegetation Conditions in Low-Relief Coastal Mountains, Nunatsiavut and NunatuKavut, Labrador
Published: 2021-05-24
Subjects: Other Applied Mathematics, Other Physical Sciences and Mathematics, Physical Sciences and Mathematics
Understanding permafrost vulnerability and resilience to climate warming is critical for predicting impacts on northern communities and ecosystems. The thermal characteristics of near-surface permafrost are influenced by effects from overlying vegetation and snow cover, both of which are changing in northern environments. The association between vegetation and snow is important in the coastal [...]
Meteorites that produce K-feldspar-rich ejecta blankets correspond to mass extinctions.
Published: 2021-05-24
Subjects: Applied Statistics, Atmospheric Sciences, Earth Sciences, Geology, Other Planetary Sciences, Paleontology, Physical Sciences and Mathematics
Meteorite impacts load the atmosphere with dust and cover the Earth‘s surface with debris. They have long been debated as a trigger of mass extinctions through Earth‘s history. Impact winters generally last <100 years, whereas ejecta blankets persist for 10^3-10^5 years. Here we show that only meteorite impacts that emplaced ejecta blankets rich in K-feldspar (Kfs) correlate to Earth system [...]
What sets aeolian dune height?
Published: 2021-05-24
Subjects: Climate, Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Earth's major sand seas are often populated with giant dunes, up to hundreds of meters in height and kilometers in wavelength. These massive sediment piles, visible from space on our planet and across the Solar System, indicate that conditions for sand transport have persisted for millenia. Unraveling how giant dunes form therefore has implications for understanding atmospheric flows and climatic [...]
Consensus-Based Rock Glacier Inventorying in the Torngat Mountains, Northern Labrador
Published: 2021-05-21
Subjects: Physical Sciences and Mathematics
The Torngat Mountains of northern Labrador are an Arctic cordilleran mountain range located at the southern limit of the Canadian Arctic. Sparse observations of periglacial landforms including rock glaciers and ice-cored moraines imply that permafrost may be widespread, but limited in situ information is available for the region. In this study, we provide the first comprehensive feature inventory [...]
Permafrost Investigations Below The Marine Limit At Nain, Nunatsiavut, Canada
Published: 2021-05-21
Subjects: Physical Sciences and Mathematics
Discontinuous permafrost is a challenge for development in the coastal communities of Nunatsiavut, Labrador, northeast Canada, where local high relief limits suitable terrain for construction. These issues are particularly pronounced in Nain, the largest and northernmost community in Nunatsiavut, which is undergoing rapid population growth and expansion. In this study, DC electrical resistivity [...]
Plume —lid interactions during the Archean and implications for the generation of early continental crust
Published: 2021-05-21
Subjects: Physical Sciences and Mathematics
Many Archean terranes are interpreted to have a tectonic and metamorphic evolution that indicates intra-crustal reorganization driven by lithospheric-scale gravitational instabilities. These processes are associated with the production of a significant amount of felsic and mafic crust, and are widely regarded to be a consequence of plume-lithosphere interactions. The juvenile Archean felsic [...]
Tectonostratigraphy of the northern Okavango Delta and Rift Zone, Botswana
Published: 2021-05-21
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
The Okavango Rift Zone (ORZ) and Okavango Delta in Northwest Botswana are Earth’s youngest continental rift system and largest inland delta. The delta and its underlying sediments record the effects of incipient rifting on the geomorphology and stratigraphy within the (incipient) southwestern arm of the East African Rift System in Botswana. Three open questions that we use river-borne [...]
Exhuming the Canadian Shield: preliminary interpretations from low-temperature thermochronology and significance for the sedimentary succession of the Hudson Bay Basin
Published: 2021-05-20
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics, Stratigraphy, Tectonics and Structure
The geological history of the Canadian Shield is difficult to constrain because the sedimentary record is missing in those areas where Precambrian basement is exposed at the surface. This study presents preliminary results and interpretations of new apatite fission-track (AFT) analyses to elucidate the low-temperature (< 120 °C) history across Canada. The AFT modelling of samples from Southampton [...]
Goal-Oriented Metric-Based Mesh Adaptive Tidal Farm Modelling
Published: 2021-05-20
Subjects: Physical Sciences and Mathematics
The modelling of a tidal array farm is an inherently multi-scale endeavour. It requires the simultaneous resolution of tidal processes across tens or hundreds of kilometres of coastal ocean (including estuaries, or even entire seas), the hydrodynamics in the neighbourhood of the farm (hundreds of metres), the wakes of individual turbines (metres, or tens of metres) and device [...]
Contributions to Polar Amplification in CMIP5 and CMIP6 Models
Published: 2021-05-18
Subjects: Physical Sciences and Mathematics
As a step towards understanding the fundamental drivers of polar climate change, we evaluate contributions to polar warming and its seasonal and hemispheric asymmetries in Coupled Model Intercomparison Project phase 6 (CMIP6) as compared with CMIP5. CMIP6 models broadly capture the observed pattern of surface- and winter-dominated Arctic warming that has outpaced both tropical and Antarctic [...]
Thermal Modelling Of Post-Fire Permafrost Change Under A Warming Coastal Subarctic Climate, Eastern Canada
Published: 2021-05-18
Subjects: Earth Sciences, Physical Sciences and Mathematics
Forest fires are known to have lasting thermal impacts on permafrost, but there are no previous studies of such effects along the eastern Canadian coastline. One-dimensional thermal modelling was used to examine the ground thermal regime at a coastal forest fire site in the discontinuous permafrost zone near Nain (56.5°N), Nunatsiavut, eastern Canada. Simulations were undertaken for both the [...]