Preprints

Filtering by Subject: Statistics and Probability

A Physics-Based Decorrelation Phase CovarianceModel for Noise Reduction in UnwrappedInterferometric Phase Stacks

Yujie Zheng, Howard Zebker, Roger Michaelides

Published: 2020-10-23
Subjects: Earth Sciences, Statistics and Probability

The accuracy of geophysical parameter estimation made with Interferometric Synthetic Aperture Radar (InSAR) time-series techniques can be improved with rapidly increasing available data volumes, and with the development of noise covariance matrices applicable to joint analysis of networks of interferograms. Here we present a physics-based decorrelation phase covariance model and discuss [...]

Sedimentary structures discriminations with hyperspectral imaging on sediment cores

Kévin Jacq, Rapuc William, Benoit Alexandre, Coquin Didier, Fanget Bernard, Yves Perrette, Pierre Sabatier, Wilhelm Bruno, Debret Maxime, Fabien Arnaud

Published: 2020-07-17
Subjects: Analytical Chemistry, Chemistry, Earth Sciences, Environmental Chemistry, Environmental Monitoring, Environmental Sciences, Multivariate Analysis, Optics, Physical Sciences and Mathematics, Physics, Sedimentology, Statistical Models, Statistics and Probability

Hyperspectral imaging (HSI) is a non-destructive high-resolution sensor, which is currently under significant development to analyze geological areas with remote devices or natural samples in a laboratory. In both cases, the hyperspectral image provides several sedimentary structures that need to be separated to temporally and spatially describe the sample. Sediment sequences are composed of [...]

Climate has contrasting direct and indirect effects on armed conflicts

David Helman, Ben Zaitchik, Chris Funk

Published: 2020-07-08
Subjects: Environmental Indicators and Impact Assessment, Environmental Monitoring, Environmental Sciences, Environmental Studies, Geography, Human Geography, International and Area Studies, Library and Information Science, Life Sciences, Nature and Society Relations, Physical and Environmental Geography, Physical Sciences and Mathematics, Remote Sensing, Social and Behavioral Sciences, Statistics and Probability

There is an active debate regarding the influence that climate has on the risk of armed conflict, which stems from challenges in assembling unbiased datasets, competing hypotheses on the mechanisms of climate influence, and the difficulty of disentangling direct and indirect climate effects. We use gridded historical non-state conflict records, satellite data, and land surface models in a [...]

GANSim: Conditional Facies Simulation Using an Improved Progressive Growing of Generative Adversarial Networks (GANs)

Suihong Song, Tapan Mukerji, Jiagen Hou

Published: 2020-07-05
Subjects: Artificial Intelligence and Robotics, Computer Sciences, Earth Sciences, Geology, Hydrology, Mathematics, Physical Sciences and Mathematics, Sedimentology, Statistical Models, Statistics and Probability

Conditional facies modeling combines geological spatial patterns with different types of observed data, to build earth models for predictions of subsurface resources. Recently, researchers have used generative adversarial networks (GANs) for conditional facies modeling, where an unconditional GAN is first trained to learn the geological patterns using the original GANs loss function, then [...]

Exposure and vulnerability estimation for modelling flood losses to commercial assets in Europe

Dominik Paprotny, Heidi Kreibich, Oswaldo Morales-Nápoles, Attilio Castellarin, Francesca Carisi3, Kai Schröter

Published: 2020-07-05
Subjects: Earth Sciences, Hydrology, Multivariate Analysis, Physical Sciences and Mathematics, Statistics and Probability

Commercial assets comprise buildings, machinery and equipment, which are susceptible to floods. Existing damage models and exposure estimation methods for this sector have limited transferability between flood events. In this study we introduce two methodologies aiming at broader applicability: (1) disaggregation of economic statistics to obtain detailed building-level estimates of replacement [...]

Seasonal impact-based mapping of compound hazards

John Hillier, Richard Dixon

Published: 2020-06-17
Subjects: Applied Mathematics, Atmospheric Sciences, Climate, Earth Sciences, Environmental Sciences, Hydrology, Mathematics, Multivariate Analysis, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Statistics and Probability

Impact-based, seasonal mapping of compound hazards is proposed. It is pragmatic, identifies phenomena to drive the research agenda, produces outputs relevant to stakeholders, and could be applied to many hazards globally. Illustratively, flooding and wind damage can co-occur, worsening their joint impact, yet where wet and windy seasons combine has not yet been systematically mapped. Here, [...]

Large model parameter and structural uncertainties in global projections of urban heat waves

Zhonghua Zheng, Lei Zhao, Keith W. Oleson

Published: 2020-06-10
Subjects: Atmospheric Sciences, Civil and Environmental Engineering, Computer Sciences, Earth Sciences, Engineering, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Risk Analysis, Statistics and Probability

Urban heat waves (UHWs) are strongly associated with socioeconomic impacts. Reliable projections of these extremes are pressingly needed for local actions in the context of extreme event preparedness and mitigation. Such information, however, is not available because current multi-model projections largely lack a representation of urban areas. Here, we use a newly-developed urban climate emulator [...]

Observation-based Simulations of Humidity and Temperature Using Quantile Regression

Andrew Poppick, Karen A. McKinnon

Published: 2020-05-29
Subjects: Atmospheric Sciences, Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Statistics and Probability

The human impacts of changes in heat events depend on changes in the joint behavior of temperature and humidity. Little is currently known about these complex joint changes, either in observations or projections from general circulation models (GCMs). Further, GCMs do not fully reproduce the observed joint distribution, implying a need for simulation methods that combine information from GCMs [...]

RECENT RAPID SEA LEVEL RISE IN DUBLIN BAY BASED ON TIDE GAUGE ANALYSIS

Amin Shoari Nejad, Andrew Parnell, Alice Greene, Brian P Kelleher, Gerard McCarthy

Published: 2020-05-28
Subjects: Applied Statistics, Climate, Earth Sciences, Life Sciences, Oceanography and Atmospheric Sciences and Meteorology, Other Earth Sciences, Other Life Sciences, Physical Sciences and Mathematics, Planetary Sciences, Statistics and Probability

We analysed tide gauges at Dublin port and its environs over the period 1938-2018. With three different tide gauges in the vicinity of the main Dublin port gauge, we merged the data sets and validated them against each other. The recordings of all four tide gauges were found to be in good agreement between 2003-2015, though this was markedly less so from 2016 to the present. We estimate the sea [...]

Probabilistic soil moisture dynamics of water- and energy-limited ecosystems

Estefanía Muñoz, Andrés Ochoa, Germán Poveda, Ignacio Rodríguez-Iturbe

Published: 2020-05-17
Subjects: Agriculture, Agronomy and Crop Sciences Life Sciences, Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Engineering, Environmental Sciences, Forest Sciences, Hydrology, Life Sciences, Physical Sciences and Mathematics, Plant Sciences, Statistical Models, Statistics and Probability

This paper presents an extension of the stochastic ecohydrological model for soil moisture dynamics at a point of Rodriguez-Iturbe et al. (1999) and Laio et al. (2001). In the original model, evapotranspiration is a function of soil moisture and vegetation parameters, so that the model is suitable for water-limited environments. Our extension introduces a dependence on maximum evapotranspiration [...]

Three Common Statistical Missteps We Make in Reservoir Characterization

Frank Male, Jerry L. Jensen

Published: 2020-05-11
Subjects: Chemical Engineering, Earth Sciences, Engineering, Geology, Petroleum Engineering, Physical Sciences and Mathematics, Statistical Methodology, Statistics and Probability

Reservoir characterization analysis resulting from incorrect applications of statistics can be found in the literature, particularly in applications where integration of various disciplines is needed. Here, we look at three misapplications of ordinary least squares linear regression (LSLR) and show how they can lead to poor results and offer better alternatives, where available. The issues are [...]

Comparison of permeability predictions on cemented sandstones with physics-based and machine learning approaches

Frank Male, Jerry L. Jensen, Larry W. Lake

Published: 2020-02-06
Subjects: Chemical Engineering, Earth Sciences, Engineering, Hydrology, Multivariate Analysis, Petroleum Engineering, Physical Sciences and Mathematics, Statistics and Probability

Permeability prediction has been an important problem since the time of Darcy. Most approaches to solve this problem have used either idealized physical models or empirical relations. In recent years, machine learning (ML) has led to more accurate and robust, but less interpretable empirical models. Using 211 core samples collected from 12 wells in the Garn Sandstone from the North Sea, this [...]

Evaluating the INLA-SPDE approach for Bayesian modeling of earthquake damages from geolocated cluster data

Bradley Wilson

Published: 2020-01-27
Subjects: Physical Sciences and Mathematics, Statistical Models, Statistics and Probability

Modeled damage estimates are an important source of information in the hours to weeks following major earthquake disasters, but often lack sufficient spatial resolution for highlighting specific areas of need. Using damage assessment data from the 2015 Gorkha, Nepal Earthquake, this paper evaluates a Bayesian spatial model (INLA-SPDE) for interpolating geolocated damage survey data onto 1 km2 [...]

Advanced ML and AI Approaches for Proxy-based Optimization of CO2-Enhanced Oil Recovery in Heterogeneous Clastic Reservoirs

Watheq J. Al-Mudhafar, Dandina N Rao, Sanjay Srinivasan

Published: 2019-12-04
Subjects: Artificial Intelligence and Robotics, Computer Sciences, Design of Experiments and Sample Surveys, Earth Sciences, Multivariate Analysis, Other Earth Sciences, Physical Sciences and Mathematics, Programming Languages and Compilers, Statistics and Probability

The EOS-compositional reservoir simulation, Design of Experiments, and Proxy Modeling were integrated to obtain the optimal future performance scenario and to construct the most accurate simplified model alternative to the complex reservoir flow simulation. This integrated workflow was adopted on a sector of the main pay/upper sandstone member in the South Rumaila oil field, located in Iraq. [...]

A 2,000-year Bayesian NAO reconstruction from the Iberian Peninsula

Armand Hernández, Guiomar Sánchez-López, Sergi Pla-Rabes, Laia Comas-Bru, Andrew Parnell, Niamh Cahill, Adelina Geyer, Ricardo M Trigo, Santiago Giralt

Published: 2019-11-27
Subjects: Applied Statistics, Climate, Earth Sciences, Oceanography and Atmospheric Sciences and Meteorology, Other Earth Sciences, Physical Sciences and Mathematics, Statistics and Probability

The North Atlantic Oscillation (NAO) is the major atmospheric mode that controls winter European climate variability because its strength and phase determine regional temperature, precipitation and storm tracks. The NAO spatial structure and associated climatic impacts over Europe are not stationary making it crucial to understanding its past evolution in order to improve the predictability of [...]

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