Preprints
Filtering by Subject: Environmental Sciences
Spatial association between regionalizations using the information-theoretical V-measure
Published: 2018-04-19
Subjects: Categorical Data Analysis, Computer Sciences, Environmental Sciences, Geographic Information Sciences, Geography, Numerical Analysis and Scientific Computing, Physical Sciences and Mathematics, Social and Behavioral Sciences, Statistics and Probability, Theory and Algorithms
There is a keen interest in inferring spatial associations between different variables spanning the same study area. We present a method for quantitative assessment of such associations in the case where spatial variables are either in the form of regionalizations or in the form of thematic maps. The proposed index of spatial association – called the V-measure – is adapted from a measure [...]
River deltas as Multiplex networks: A framework for studying multi-process multi-scale connectivity via coupled-network theory
Published: 2018-04-13
Subjects: Applied Mathematics, Dynamic Systems, Earth Sciences, Environmental Sciences, Geomorphology, Hydrology, Mathematics, Non-linear Dynamics, Physical Sciences and Mathematics, Physics, Statistical, Nonlinear, and Soft Matter Physics
Transport of water, nutrients or energy fluxes in many natural or coupled human-natural systems occurs along different pathways that often have a wide range of transport timescales and might exchange fluxes with each other dynamically (e.g., surface-subsurface). Understanding this type of transport is key to predicting how landscapes will change under changing forcing. Here, we present a general [...]
Fine-Scale SAR Soil Moisture Estimation in the Subarctic Tundra
Published: 2018-03-31
Subjects: Environmental Monitoring, Environmental Sciences, Physical Sciences and Mathematics
In the subarctic tundra, soil moisture information can benefit permafrost monitoring and ecological studies, but fine-scale remote sensing approaches are lacking. We explore the suitability of C-band SAR, paying attention to two challenges soil moisture retrieval faces. First, the microtopography and the heterogeneous organic soils impart unique microwave scattering properties, even in absence of [...]
Ambient noise image Campi Flegrei 2011-2013
Published: 2018-03-26
Subjects: Earth Sciences, Environmental Monitoring, Environmental Sciences, Physical Sciences and Mathematics, Tectonics and Structure, Volcanology
Earthquakes at Campi Flegrei have been low-magnitude and sparse for more than thirty years, denying onshore monitoring observations of their usual source for structural constraint: seismic tomography. Here, we used ambient seismic noise recorded between 2011 and 2013 to reconstruct period-dependent Rayleigh-wave velocity maps of caldera-wide structures and volcanic reservoirs. The lowest [...]
Knowledge in the Dark: Scientific Challenges and Ways Forward
Published: 2018-03-26
Subjects: Earth Sciences, Education, Environmental Sciences, Environmental Studies, Higher Education, Language and Literacy Education, Liberal Studies, Library and Information Science, Life Sciences, Medicine and Health Sciences, Physical Sciences and Mathematics, Public Health, Science and Mathematics Education, Social and Behavioral Sciences
We propose the concept of knowledge in the dark – or short: dark knowledge – and outline how it can help clarify why in our current era of Big Data, the knowledge (i.e. evidence-based understanding) of people does not seem to be substantially increasing despite a rapid increase in produced data and information. Key reasons underlying dark knowledge are: (1) the production of biased, erroneous or [...]
Missing emissions from post-monsoon agricultural fires in northwestern India: regional limitations of MODIS burned area and active fire products
Published: 2018-03-21
Subjects: Earth Sciences, Environmental Indicators and Impact Assessment, Environmental Sciences, Physical Sciences and Mathematics
A rising source of outdoor emissions in northwestern India is crop residue burning, occurring after the monsoon (kharif) and winter (rabi) crop harvests. In particular, post-monsoon rice residue burning, which occurs annually from October to November and is linked to increasing mechanization, coincides with meteorological conditions that enhance short-term air quality degradation. Here we examine [...]
The Extraordinary Mediocrity of the Holocene
Published: 2018-03-15
Subjects: Climate, Computer Sciences, Earth Sciences, Environmental Sciences, Oceanography and Atmospheric Sciences and Meteorology, Other Physical Sciences and Mathematics, Physical Sciences and Mathematics, Planetary Sciences
The extinction of multiple genera of large-bodied mammals during the Holocene interglacial transition has been attributed to three hypothesized causes: human migration, climate change, and an extra-terrestrial impact. Two of these hypotheses, climate change and extra-terrestrial impactor, would predict that the Holocene interglacial transition was uniquely stressful for large-bodied mammals. To [...]
Climatic influences on the offset between d18O of cave drip waters and precipitation inferred from global monitoring data
Published: 2018-03-08
Subjects: Earth Sciences, Engineering, Environmental Monitoring, Environmental Sciences, Geochemistry, Hydrology, Physical Sciences and Mathematics, Speleology
We present a meta-analysis of data from 22 caves and 96 drip sites from 4 continents where both the cave drip water d18O and the weighted mean d18O of precipitation have been measured. Drip water d18O is similar to the weighted mean d18O of precipitation (within ± 0.3 ‰) for sites where mean annual temperature (MAT) is less than 15 °C (85% of drips where MAT < 15 °C) and an aridity index [...]
Uncertainty in sea level rise projections due to the dependence between contributors
Published: 2018-03-08
Subjects: Applied Statistics, Climate, Earth Sciences, Environmental Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Probability, Statistical Models, Statistics and Probability
Sea level rises at an accelerating pace threatening coastal communities all over the world. In this context sea level projections are key tools to help risk mitigation and adaptation. Sea level projections are often made using models of the main contributors to sea level rise (e.g. thermal expansion, glaciers, ice sheets...). To obtain the total sea level these contributions are added, therefore [...]
What caused Earths largest mass extinction event? New evidence from the Permian-Triassic boundary in northeastern Utah
Published: 2018-02-26
Subjects: Biogeochemistry, Biology, Chemistry, Earth Sciences, Environmental Chemistry, Environmental Indicators and Impact Assessment, Environmental Sciences, Geology, Life Sciences, Paleobiology, Paleontology, Physical Sciences and Mathematics, Sedimentology
The discovery of a Permian-Triassic boundary section in northeastern Utah reveals a detailed record of events that led to one of the greatest mass extinctions on the planet. From 83% to 97% of the species living on the planet went extinct during this relatively short interval of geological time, which defines the major geological boundary between the Paleozoic and Mesozoic Eras. The cause and [...]
Groundwater controls on post-fire permafrost thaw: Water and energy balance effects
Published: 2018-02-21
Subjects: Earth Sciences, Environmental Sciences, Hydrology, Physical Sciences and Mathematics
Fire frequency and severity are increasing in high latitude regions, but the degree to which groundwater flow impacts the response of permafrost to fire remains poorly understood. Here, we use the Anaktuvuk River Fire (Alaska, USA) as an example for simulating groundwater-permafrost interactions following fire. We identify key thermal and hydrologic parameters controlling permafrost response to [...]
Global assessment and mapping of changes in mesoscale landscapes: 1992–2015
Published: 2018-02-15
Subjects: Categorical Data Analysis, Computer Sciences, Earth Sciences, Environmental Sciences, Geographic Information Sciences, Geography, Longitudinal Data Analysis and Time Series, Numerical Analysis and Scientific Computing, Physical Sciences and Mathematics, Social and Behavioral Sciences, Spatial Science, Statistics and Probability
Monitoring global land cover changes is important because of concerns about their impact on environment and climate. The release by the European Space Agency (ESA) of a set of worldwide annual land cover maps covering the 1992–2015 period makes possible a quantitative assessment of land change on the global scale. While ESA land cover mapping effort was motivated by the need to better [...]
Towards machine ecoregionalization of Earth’s landmass using pattern segmentation method
Published: 2018-02-15
Subjects: Categorical Data Analysis, Computer Sciences, Earth Sciences, Environmental Sciences, Geographic Information Sciences, Geography, Numerical Analysis and Scientific Computing, Physical Sciences and Mathematics, Social and Behavioral Sciences, Spatial Science, Statistics and Probability
We present and evaluate a quantitative method for delineation of ecophysigraphic regions throughout the entire terrestrial landmass. The method uses the new pattern-based segmentation technique which attempts to emulate the qualitative, weight-of-evidence approach to a delineation of ecoregions in a computer code. An ecophysiographic region is characterized by homogeneous physiography defined by [...]
Global inventory of landscape patterns and latent variables of landscape spatial configuration
Published: 2018-02-15
Subjects: Biodiversity, Earth Sciences, Environmental Indicators and Impact Assessment, Environmental Sciences, Geographic Information Sciences, Geography, Life Sciences, Physical Sciences and Mathematics, Social and Behavioral Sciences, Spatial Science
We present a regionalization of the entire Earth’s landmass into land units of homogeneous landscape patterns. The input to the regionalization is a high resolution Global Land Cover (GLC) dataset. The GLC is first divided into local landscapes – small non-overlapping square blocks of GLC cells. These blocks are agglomerated into much larger land units using a pattern-based segmentation [...]
Distributions of geohopanoids in peat: implications for the use of hopanoid-based proxies in natural archives
Published: 2018-02-04
Subjects: Biogeochemistry, Chemistry, Earth Sciences, Environmental Sciences, Geochemistry, Other Physical Sciences and Mathematics, Physical Sciences and Mathematics
Hopanoids are pentacyclic triterpenoids produced by a wide range of bacteria. Within modern settings, hopanoids mostly occur in the biological 17β,21β(H) configuration. However, in some modern peatlands, the C31 hopane is present as the thermally-mature 17α,21β(H) stereoisomer. This has traditionally been ascribed to isomerisation at the C-17 position catalysed by the acidic environment. However, [...]