Preprints
There are 4724 Preprints listed.
Systematic calculation of finite-time mixed singular vectors and characterization of error growth for persistent coherent atmospheric disturbances over Eurasia
Published: 2021-08-12
Subjects: Physical Sciences and Mathematics
Singular vectors (SVs) have long been employed in the initialization of ensemble numerical weather prediction (NWP) in order to capture the structural organization and growth rates of those perturbations or “errors” associated with initial condition errors and instability processes of the large scale flow. Due to their (super) exponential growth rates and spatial scales, initial SVs are typically [...]
Storage, evolution, and mixing in basaltic eruptions from around the Okataina Volcanic Centre, Taupō Volcanic Zone, Aotearoa New Zealand
Published: 2021-08-07
Subjects: Physical Sciences and Mathematics
Volcanic Zone, Aotearoa New Zealand. Although best known for its high rates of explosive rhyolitic volcanism, there are several examples of basaltic to basaltic-andesite contributions to OVC eruptions. These range from minor involvement of basalt in rhyolitic eruptions to the exclusively basaltic 1886 C.E. plinian eruption of Tarawera. To explore the basaltic component supplying this dominantly [...]
A strontium isoscape of Italy for provenance studies
Published: 2021-08-06
Subjects: Geochemistry
We present a novel database of environmental and geological 87Sr/86Sr values (n = 1920) from Italy, using literature data and newly analysed samples, for provenance purposes. We collected both bioavailable and non-bioavailable (i.e. rocks and bulk soils) data to attain a broader view of the Sr isotope variability of the Italian peninsula. These data were used to build isotope variability maps, [...]
On the overlooked impact of river dams on beach erosion worldwide
Published: 2021-08-04
Subjects: Engineering
The current retreat of the world's coastline has a profound impact on human activities and ecosystems. The scientific community has primarily focused on the potential impact of sea level rise. At the global scale, the contribution of river sand loads to coastal erosion has been overlooked. Here we present the first global sand pathway model from land to sea. Our model reveals that sand tends to [...]
Calibration, inversion and sensitivity analysis for hydro-morphodynamic models
Published: 2021-08-03
Subjects: Applied Mathematics, Fluid Dynamics, Geomorphology, Numerical Analysis and Computation, Partial Differential Equations, Programming Languages and Compilers
The development of reliable, sophisticated hydro-morphodynamic models is essential for protecting the coastal environment against hazards such as flooding and erosion. There exists a high degree of uncertainty associated with the application of these models, in part due to incomplete knowledge of various physical, empirical and numerical closure related parameters in both the hydrodynamic and [...]
Geochemical constraints on the structure of the Earth’s deep mantle and the origin of the LLSVPs
Published: 2021-08-03
Subjects: Physical Sciences and Mathematics
Geophysical analysis of the Earth’s lower mantle has revealed the presence of two superstructures characterized by low shear wave velocities on the core-mantle boundary. These Large Low Shear Velocity Provinces (LLSVPs) play a crucial role in the dynamics of the lower mantle and act as the source region for deep-seated mantle plumes. However, their origin, and the characteristics of the [...]
Drivers of phytoplankton responses to summer storms in a stratified lake: a modelling study
Published: 2021-08-03
Subjects: Hydrology, Other Environmental Sciences, Terrestrial and Aquatic Ecology
Extreme wind events affect lake phytoplankton amongst others by deepening the mixed layer and increasing internal nutrient loading. Both increases and decreases of phytoplankton biomass after storms have been observed, but the precise mechanisms driving these responses remain poorly understood or quantified. In this study, we coupled a one-dimensional physical model to a biogeochemical model to [...]
The role of surface processes in basin inversion and breakup unconformity
Published: 2021-08-03
Subjects: Earth Sciences, Geology, Stratigraphy, Tectonics and Structure
At divergent plate boundaries, extensional tectonics lead to subsidence, continental rifting and the formation of continental margins. Yet, within this extensional context, transient compressional structures (stress inversion) and phases of uplift (depth inversion) are frequently recorded with no corresponding change in plate motion. Changes in gravitational potential energy during the rifting [...]
Making Drone Data FAIR Through a Community-Developed Information Framework
Published: 2021-08-02
Subjects: Computer and Systems Architecture, Library and Information Science
Small Uncrewed Aircraft Systems (sUAS) are an increasingly common tool for data collection in many scientific fields. However, there are few standards or best practices guiding the collection, sharing, or publication of data collected with these tools. This makes collaboration, data quality control, and reproducibility challenging. To that end, we have used iterative rounds of data modeling and [...]
Cryoturbation leads to iron-organic carbon associations along a permafrost soil chronosequence in northern Alaska
Published: 2021-08-02
Subjects: Physical Sciences and Mathematics
In permafrost soils, substantial amounts of organic carbon (OC) are potentially protected from microbial degradation and transformation into greenhouse gases by association with reactive iron (Fe) minerals. As permafrost environments respond to climate change, increased drainage of thaw lakes in permafrost regions is predicted. Soils will subsequently develop on these drained thaw lakes, but the [...]
Competition between 3D structural inheritance and kinematics during rifting: insights from analogue models
Published: 2021-08-01
Subjects: Physical Sciences and Mathematics
The competition between the impact of inherited weaknesses and plate kinematics determines the location and style of deformation during rifting, yet the relative impacts of these “internal” and “external” factors remain poorly understood, especially in 3D. In this study we used brittle-viscous analogue models to assess how multiphase rifting, i.e., changes in plate divergence rate or direction, [...]
Salt welding during canopy advance and shortening in the Green Canyon Area, northern Gulf of Mexico
Published: 2021-07-30
Subjects: Earth Sciences, Geology, Other Earth Sciences, Tectonics and Structure
Welds form due to tectonically-induced thinning and/or dissolution of salt, with their composition and completeness thought to at least partly reflect their structural position within the salt-tectonic system. Despite their importance as seals or migration pathways for accumulations of hydrocarbons and CO2, we have relatively few published examples of drilled subsurface welds; such examples would [...]
Microbial iron(III) reduction during palsa collapse promotes greenhouse gas emissions before complete permafrost thaw
Published: 2021-07-30
Subjects: Physical Sciences and Mathematics
Reactive iron (Fe) minerals can preserve organic carbon (OC) in soils overlying intact permafrost. With permafrost thaw, reductive dissolution of iron minerals releases Fe and OC into the porewater, potentially increasing the bioavailability of OC for microbial decomposition. However, the stability of this so-called rusty carbon sink, the microbial community driving mineral dissolution, the [...]
A theory of spontaneous tropical cyclogenesis from quasi-random convection
Published: 2021-07-30
Subjects: Physical Sciences and Mathematics
How the cumulus clouds organize into a tropical cyclone remains poorly understood. The difficulty lies in that the deep convection is noisy at the kilometer scale, but follows the physical feedbacks at the mesoscale. We build a barotropic numerical model to understand the interaction of the stochastic and deterministic processes in the genesis of a tropical depression. Deep convection is [...]
Imprint of the Pacific Walker Circulation in global precipitation δ18O
Published: 2021-07-30
Subjects: Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
*This article is now published, and freely available from Journal of Climate at https://doi.org/10.1175/JCLI-D-21-0190.1* Characterising variability in the global water cycle is fundamental to predicting impacts of future climate change; understanding the role of the Pacific Walker circulation (PWC) in the regional expression of global water cycle changes is critical to understanding this [...]