Preprints
There are 6976 Preprints listed.
Detection of Point-Source Methane Enhancements from MethaneSAT Observations with Target-Driven Spectral Matching Algorithm
Published: 2025-09-28
Subjects: Atmospheric Sciences, Environmental Sciences
Methane is a potent greenhouse gas with large emissions often arising from localized point sources in industrial facilities. MethaneSAT, launched in 2024, observes the 1598-1683 nm band with sub-nanometer resolution and 100 m × 400 m footprints, enabling sensitive detection of methane absorption. We introduce an updated matched filter (BCMF) with covariance exclusion and a statistical correction [...]
Downhole distributed acoustic sensing reveals the wave field structure of the coastal microseisms
Published: 2020-10-21
Subjects: Engineering, Physical Sciences and Mathematics
Ocean-generated seismic waves are omnipresent in passive seismic records around the world and present both a challenge for earthquakes observations and an input signal for interferometric methods for characterisation of the Earth's interior. Understanding of these waves requires the knowledge of the depth-dependence of the oceanic noise at the transition into continent. To this end, we examine 80 [...]
Dynamical analysis of a reduced model for the North Atlantic Oscillation
Published: 2020-10-21
Subjects: Applied Mathematics, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The dynamics of the North Atlantic Oscillation (NAO) are analyzed through a data-driven model obtained from atmospheric reanalysis data. We apply a regularized vector autoregressive clustering technique to identify recurrent and persistent states of atmospheric circulation patterns in the North Atlantic sector (110W-0E, 20N-90N). In order to analyze the dynamics associated with the resulting [...]
Assessing streamflow sensitivity to precipitation variability in karst-influenced catchments with unclosed water balance
Published: 2020-10-21
Subjects: Physical Sciences and Mathematics
Karst hydrological models are widely used for simulating groundwater dynamics at the aquifer scale. However, modeling streamflow of a topographic catchment that is partially covered by karst is rarely reported. This is due to difficulties of properly considering the strong differences of karstic and non-karstic hydrodynamics and the widespread occurrence of unclosed water balances in karstic [...]
Exposures and behavioral responses to wildfire smoke
Published: 2021-10-12
Subjects: Environmental Monitoring, Environmental Public Health, Environmental Studies, Statistical Models
The impacts of environmental change on human outcomes often depend on local exposures and behavioral responses that are challenging to observe with traditional administrative or sensor data. We show how data from private pollution sensors, cell phones, social media posts, and internet search activity yield new insights on exposures and behavioral responses during large wildfire smoke events [...]
Nature of the Cuvier Abyssal Plain crust, offshore NW Australia
Published: 2021-02-24
Subjects: Physical Sciences and Mathematics
Magnetic stripes have long been assumed to be indicative of oceanic crust. However, continental crust heavily intruded by magma can also record magnetic stripes. We re-evaluate the nature of the Cuvier Abyssal Plain (CAP), offshore NW Australia, which hosts magnetic stripes and has previously been defined as oceanic crust. We show chemical data from a basalt within the CAP, previously described [...]
A data assimilation approach to last millennium temperature field reconstruction using a limited high-sensitivity proxy network
Published: 2020-10-23
Subjects: Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Paleoclimate field reconstructions using data assimilation commonly employ large proxy networks, which are often composed of records that have a complex range of sensitivities to the target climate field. This can introduce biases into reconstructions or decrease overall skill. Smaller networks of highly-sensitive proxies provide an alternative, but have not been extensively used for assimilation [...]
Characterizing seismic scattering in 3D heterogeneous Earth by a single parameter
Published: 2020-10-24
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
We derive a theoretical parameter for three seismic scattering regimes where seismic wavelengths are either much shorter, similar, or much longer than the correlation length of small-scale Earth heterogeneities. We focus our analysis on the power spectral density of the von Karman autocorrelation function, used to characterize the spatial heterogeneity of small-scale variations of elastic rock [...]
The importance of the study of igneous rocks and compositions to constrain the martian planetary evolution
Published: 2020-10-21
Subjects: Physical Sciences and Mathematics
This white paper summarizes the scientific importance of studying igneous compositions in meteorites, surface samples, and through orbital analyses to better constrain the geology of Mars as a whole and better understand the geological processes that have shaped Mars in the past and present. In support of martian igneous studies, we strongly advocate for the following in the upcoming [...]
Structure-from-Motion on shallow reefs and beaches: potential and limitations of consumer-grade drones to reconstruct topography and bathymetry
Published: 2020-10-21
Subjects: Civil Engineering, Engineering, Environmental Engineering, Environmental Monitoring, Environmental Studies, Fluid Dynamics, Fresh Water Studies, Geographic Information Sciences, Hydraulic Engineering, Other Civil and Environmental Engineering, Other Environmental Sciences, Remote Sensing
Reconstructing the topography of shallow underwater environments using Structure-from-Motion – Multi View Stereo (SfM-MVS) techniques applied to aerial imagery from Unmanned Aerial Vehicles (UAVs) is a challenging problem, as it involves non-linear distortions caused by water refraction. This study presents an experiment with aerial photographs collected with a consumer-grade UAV on the [...]
Weak influence of paleoenvironmental conditions on the subsurface biosphere of Lake Ohrid in the last 515 ka
Published: 2020-10-21
Subjects: Life Sciences
Lacustrine sediments are widely used to investigate the impact of climatic change on biogeochemical cycling. In these sediments, subsurface microbial communities are major actors of this cycling but can also affect the sedimentary record and overprint the original paleoenvironmental signal. We therefore investigated the subsurface microbial communities of the oldest lake in Europe, Lake Ohrid [...]
Testing the effect of bioturbation and species abundance upon discrete-depth individual foraminifera analysis
Published: 2020-10-22
Subjects: Earth Sciences, Geology
We use a single foraminifera enabled, holistic hydroclimate-to-sediment transient modelling approach to fundamentally evaluate the efficacy of discrete-depth individual foraminifera analysis (IFA) for reconstructing past sea surface temperature (SST) variability from deep-sea sediment archives, a method that has been used for, amongst other applications, reconstructing El Niño Southern [...]
Towards a new geological time scale: A template for improved rock-based subdivision of pre-Cryogenian time
Published: 2020-10-22
Subjects: Physical Sciences and Mathematics
Four first-order (Hadean, Archean, Proterozoic and Phanerozoic eon) and nine second-order (Paleoarchean, Mesoarchean, Neoarchean, Paleoproterozoic, Mesoproterozoic, Neoproterozoic, Paleozoic, Mesozoic and Cenozoic era) units continue to provide intuitive subdivision of geological time. Major transitions in Earth’s tectonic, biological and environmental history occurred at approximately 2.5-2.3, [...]
A Physics-Based Decorrelation Phase CovarianceModel for Noise Reduction in UnwrappedInterferometric Phase Stacks
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 [...]
Inverse analysis to reconstruct hydraulic conditions of non-steady turbidity currents: Application to an ancient turbidite of the Kiyosumi Formation of the Awa Group, Boso Peninsula, central Japan
Published: 2020-10-21
Subjects: Earth Sciences, Physical Sciences and Mathematics, Sedimentology
This study proposes a new method of inverse analysis from ancient turbidites to the non-steady turbidity currents with consideration of multiple grain-size classes. The forward model employed in this study is based on the shallow water equation, and the initial condition of flows are assumed to be the lock-exchange type condition. To obtain a solution of the inverse problem, this study employed [...]