Preprints
Filtering by Subject: Physical Sciences and Mathematics
Wavelet-based wavenumber spectral estimate of eddy kinetic energy: Application to the North Atlantic
Published: 2023-02-16
Subjects: Physical Sciences and Mathematics
An ensemble of eddy-rich North Atlantic simulations is analyzed, providing estimates of eddy kinetic energy (EKE) wavenumber spectra and spectral budgets below the mixed layer where energy input from surface convection is negligible. A wavelet transform technique is used to estimate a spatially localized `pseudo-Fourier' spectrum, permitting comparisons to be made between spectra at different [...]
Temporal evolution of under-ice meltwater layers and false bottoms and their impact on summer Arctic sea ice mass balance
Published: 2023-02-16
Subjects: Earth Sciences, Glaciology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Low-salinity meltwater from Arctic sea ice and its snow cover accumulates and creates under-ice meltwater layers below sea ice. These meltwater layers can result in the formation of new ice layers, or false bottoms, at the interface of this low-salinity meltwater and colder seawater. As part of the Multidisciplinary drifting Observatory for the Study of the Arctic Climate (MOSAiC), we used a [...]
Evidence of Early Supershear Transition in the Feb 6th 2023 Mw 7.8 Kahramanmaraş Turkey Earthquake From Near-Field Records
Published: 2023-02-15
Subjects: Aerospace Engineering, Civil and Environmental Engineering, Earth Sciences, Engineering, Mechanical Engineering, Physical Sciences and Mathematics
The Mw7.8 Kahramanmaraş Earthquake was larger and more destructive than what had been expected for the tectonic setting in Southeastern Turkey. By using near-field records we provide evidence for early supershear transition on the splay fault that hosted the nucleation and early propagation of the first rupture that eventually transitioned into the East Anatolian fault. We also find, for the [...]
Statistical precursor signals for Dansgaard-Oeschger cooling transitions
Published: 2023-02-14
Subjects: Physical Sciences and Mathematics
Given the likely bistability of the Atlantic Meridional Overturning Circulation (AMOC) and its recently inferred weakening, it is important to investigate the capability of identifying robust precursor signals for a possible future AMOC collapse as well as its collapses in the past. Dansgaard-Oeschger (DO) events, manifested most clearly as abrupt Northern-Atlantic temperature jumps during [...]
Detrital zircon U-Pb ages of Proterozoic and Cretaceous sandstones of Narmada region in Central India: Implications for provenance and the closure age of the Vindhyan Basin
Published: 2023-02-12
Subjects: Physical Sciences and Mathematics
This study presents detrital zircon U-Pb ages of the Upper Bhander Sandstones from the Bhopal inlier, and the overlying Cretaceous sandstones from Jabalpur, Central India. These data are combined with existing palaeobiological evidence to address the issue of lack of convergence between geochronology and biochronology of the Upper Vindhyan succession in central India. The age-spectra of Upper [...]
Prolonged thermocline warming by near-inertial internal waves in the wakes of tropical cyclones
Published: 2023-02-11
Subjects: Physical Sciences and Mathematics
Tropical cyclones (TCs) mix vertical temperature gradients in the upper ocean and generate powerful near-inertial internal waves (NIWs) that propagate down into the deep ocean. Globally, downward mixing of heat during TC passage causes warming in the seasonal thermocline and pumps 0.15-0.6 PW of heat into the unventilated ocean. The final distribution of excess heat contributed by TCs is needed [...]
Soil moisture modulation of midlatitude heat waves
Published: 2023-02-10
Subjects: Atmospheric Sciences, Climate, Earth Sciences, Hydrology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Heat waves are broadly expected to increase in severity and frequency under climate change. Case studies highlight a number of physical mechanisms that play a role in present-day heat waves, which typically occur during a coalescence of anomalous atmospheric and land surface conditions. However, a unified model of heat wave physics is lacking, primarily owing to difficulty in disentangling the [...]
HIGH-DIMENSIONAL NONLINEAR BAYESIAN INFERENCE OF POROELASTIC FIELDS FROM PRESSURE DATA
Published: 2023-02-10
Subjects: Engineering, Physical Sciences and Mathematics
We investigate solution methods for large-scale inverse problems governed by partial differential equations (PDEs) via Bayesian inference. The Bayesian framework provides a statistical setting to infer uncertain parameters from noisy measurements. To quantify posterior uncertainty, we adopt Markov Chain Monte Carlo (MCMC) approaches for generating samples. To increase the efficiency of these [...]
Has the impact of the Earth’s orbital variation at sub-myriadal timescales been underestimated?
Published: 2023-02-07
Subjects: Physical Sciences and Mathematics
It is well established that the Earth’s long-term orbital variation affects global climate through insolation changes, particularly with respect to glacial cycles. However, there is little research into the impact of this slowly varying insolation forcing on timescales well below the smallest main periodicity, the precession, of ~ 21,000 years. Here, intermediate complexity climate modelling [...]
Clumped isotopes in globally distributed Holocene coccoliths reveal their habitat depth
Published: 2023-02-06
Subjects: Life Sciences, Physical Sciences and Mathematics
Reliable temperature reconstructions are necessary to improve climate reconstructions and comparisons with paleoclimate model simulations. Most existing paleotemperature proxies are based on organic and inorganic remains of marine organisms. Despite the evidence that the habitat depth of coccolithophores and other phytoplankton depend on their ability to balance light, nutrients, and grazing [...]
A Comparison of Contemporaneous Airborne Altimetry and Ice-Thickness Measurements of Antarctic Ice Shelves
Published: 2023-02-02
Subjects: Earth Sciences, Physical Sciences and Mathematics
Estimates of ice shelf mass loss are typically based on surface height measurements, assuming hydrostatic equilibrium and estimated firn thickness. Recent investigations, however, challenge the assumption that ice shelves are freely floating, particularly in proximity to narrow structures such as basal channels and shear margins. We compare contemporaneous measurements of Antarctic ice shelf [...]
Evaluating large-domain, hecto-meter, large-eddy simulations of trade-wind clouds using EUREC4A data
Published: 2023-02-02
Subjects: Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The meso-scale variability in cloudiness of the marine trade-wind layer is explored with large-eddy simulations of regional extent and validated against observations of the EUREC4A field campaign. 41 days of realistically forced simulations present a representative, sta- tistical view on shallow convection in the winter North Atlantic trades that includes a wide range of meso-scale variability [...]
A new mechanism for brittle failure in garnets
Published: 2023-02-01
Subjects: Earth Sciences, Physical Sciences and Mathematics
Garnet is a high-strength mineral and preserves structures that can consequently be used to understand the flow strength and evolution of stress within the lower crust. Yet, the deformation mechanisms at the brittle¬-ductile transition of garnet remain ambiguous. Here, we study garnet porphyroclasts from an eclogite facies mylonite (central Australia) to investigate the mechanisms by which garnet [...]
Climatic and cave setting influences on drip water fluorescent organic matter over an annual cycle in Northwestern Spain and implications for fluorescent laminations in stalagmites
Published: 2023-01-31
Subjects: Physical Sciences and Mathematics
Speleothem fluorescence may elucidate past vegetation dynamics, while microscale fluorescent laminations can provide annually resolved chronology. However, the origin of speleothem fluorescence and the mechanism responsible for the formation of micrometer scale fluorescent lamination in stalagmites, are not well constrained by monitoring studies. Here, we present results from a year-long monthly [...]
Quantifying Global-Warming Response of the Orographic Precipitation in a Typhoon Environment with Large-Eddy Simulations
Published: 2023-01-30
Subjects: Physical Sciences and Mathematics
The intense and moist winds in a tropical cyclone (TC) environment can produce strong mountain waves and substantially enhanced precipitation over complex terrain, yet few studies investigated how the orographic precipitation in a TC environment might respond to global warming. Here, we use large-eddy simulation to estimate the global warming-induced change in the precipitation over and near an [...]