Preprints
Filtering by Subject: Physical Sciences and Mathematics
A theory of cloud spacing for equilibrium deep convection
Published: 2022-04-05
Subjects: Physical Sciences and Mathematics
Precipitating convection is an important component of tropical atmospheric circulation. A cloud typically persists for an hour before it is shut down by its own evaporation-driven downdraft, which generates a gust front in the mixed layer that triggers neighboring clouds. There is no systematic theory for what sets the spacing of precipitating clouds, which is the first step towards understanding [...]
On the combination of the planktonic foraminiferal Mg/Ca, clumped (Δ47) and conventional (δ18O) stable isotope paleothermometers in palaeoceanographic studies
Published: 2022-04-04
Subjects: Physical Sciences and Mathematics
Assuming that foraminiferal clumped isotope (Δ47) values are independent of seawater salinity and pH, the combination of Mg/Ca, 18O and 47 values, may in theory allow us to disentangle the temperature, salinity/δ18Osw and pH signals. Here, we present a new Mg/Ca-Δ47 dataset for modern planktonic foraminifera, from various oceanographic basins and covering a large range of temperatures (from 0.2 [...]
Mg/Ca and Sr/Ca as Palaeothermometers: New data from Middle Jurassic Belemnites from Germany and Portugal.
Published: 2022-04-03
Subjects: Physical Sciences and Mathematics
In belemnite macrofossil calcite, Mg/Ca and Sr/Ca ratios have long been proposed as a palaeotemperature proxy. However, its use has proved controversial with different studies yielding contradictory results. Oxygen isotopes (
The effect of a weak asthenospheric layer on surface kinematics, subduction dynamics and slab morphology in the lower mantle
Published: 2022-04-02
Subjects: Earth Sciences, Physical Sciences and Mathematics
On Earth, the velocity at which subducting plates are consumed at their trenches (termed `subduction rate' herein) is typically 3 times higher than trench migration velocities. The subduction rate is also 5 times higher than estimated lower mantle slab sinking rates. Using simple kinematic analyses, we show that if this present-day ``kinematic state'' operated into the past, the subducting [...]
Data from the drain: a sensor framework that captures multiple drivers of chronic coastal floods
Published: 2022-04-02
Subjects: Earth Sciences, Environmental Monitoring, Environmental Sciences, Hydrology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Tide gauge water levels are commonly used as a proxy for flood incidence on land. These proxies are useful for projecting how sea-level rise (SLR) will increase the frequency of coastal flooding. However, tide gauges do not account for land-based sources of coastal flooding and therefore flood thresholds and the proxies derived from them likely underestimate the current and future frequency of [...]
Weathering intensity and lithium isotopes: A reactive transport perspective
Published: 2022-04-02
Subjects: Earth Sciences, Physical Sciences and Mathematics
Lithium isotopes have emerged as a powerful tool to probe the response of global weathering to changes in climate. Due to the preferential incorporation of 6Li into clay minerals during chemical weathering, the isotope ratio δ7Li may be used to interrogate the balance of primary mineral dissolution and clay precipitation. This balance has been linked to relative rates of chemical and physical [...]
Displacement/length scaling relationships for normal faults; a review, critique, and revised compilation
Published: 2022-03-30
Subjects: Earth Sciences, Physical Sciences and Mathematics
The relationship between normal fault displacement (D) and length (L) varies due to numerous factors, including fault size, maturity, basin tectonic history, and host rock lithology. Understanding how fault D and L relate is useful, given related scaling laws are often used to help refine interpretations of often incomplete, subsurface datasets, which has implications for hydrocarbon and [...]
Spatial scale evaluation of forecast flood inundation maps
Published: 2022-03-30
Subjects: Hydrology, Physical Sciences and Mathematics
Flood inundation forecast maps provide an essential tool to disaster management teams for planning and preparation ahead of a flood event in order to mitigate the impacts of flooding on the community. Evaluating the accuracy of forecast flood maps is essential for model development and improving future flood predictions. Conventional, quantitative binary verification measures typically provide a [...]
Late Glacial and Holocene Palaeolake History of the Última Esperanza Region of Southern Patagonia
Published: 2022-03-29
Subjects: Earth Sciences, Geochemistry, Geology, Geomorphology, Glaciology, Hydrology, Paleobiology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy, Volcanology
We undertook multiproxy analyses on two sediment cores from Lago Pato, a small lake basin at 51°S topographically separated from Lago del Toro in Torres del Paine (TdP), to provide insights into glacier dynamics and lake level change in the TdP and Última Esperanza region over the last ~30,000 cal a BP (30 ka). Lago Pato is situated in a region overridden by the Southern Patagonian Icefield [...]
Greenland ice sheet vulnerability under diverse climatic warming scenarios
Published: 2022-03-26
Subjects: Earth Sciences, Glaciology, Physical Sciences and Mathematics
Sea-level rise of even one meter will have drastic global impacts. Melting the Greenland Ice Sheet (GIS) would raise sea level by 7.4 meters. There is an urgent need to improve predictions of how quickly the GIS will contribute its first meter of sea-level rise, and from where on the ice sheet that water will come. Estimating the volume of Greenland ice that was lost during past warm periods [...]
Nanogenerators: A new paradigm in blue energy-harvesting
Published: 2022-03-26
Subjects: Engineering, Physical Sciences and Mathematics
The depletion of natural energy sources demands non-conventional efficient alternatives with sustainable utility. The outstanding performance of nanomaterials resolves the energy scarcity issue through the introduction of small-scale, energy-harvesting devices, called nanogenerators. A nanogenerator is an ambient energy-harvester with exotic features of being a lightweight, sustainable and [...]
Brittle basement deformation during the Caledonian Orogeny observed by K-Ar geochronology of illite-bearing fault gouge in west-central Sweden
Published: 2022-03-26
Subjects: Physical Sciences and Mathematics
This study presents K-Ar geochronology ages of illite from fault gouge in the crystalline basement in central-western Sweden. Samples of fault gouge were taken from two faults localizing brittle deformation along and within mafic dikes that intrude Paleoproterozoic granites. K-Ar ages from the ten dated fractions span from 823 Ma to 392 Ma. The older ages obtained, spanning from 823 to 477 Ma, [...]
Structural relationships in and around the Rheasilvia basin on Vesta
Published: 2022-03-25
Subjects: Physical Sciences and Mathematics
The Rheasilvia basin is an impact structure occupying most of Vesta’s southern hemisphere. Divalia Fossae, a set of circum-equatorial troughs, were previously proposed to be concentric around the basin, which is widely regarded as evidence that the Rheasilvia impact directly caused the formation of the troughs. Here, we produce a structural map of Rheasilvia that allows for geologic [...]
Unexpected space weather causing the reentry of 38 Starlink satellites in February 2022
Published: 2022-03-25
Subjects: Physical Sciences and Mathematics
The accidental reentry of 38 Starlink satellites occurred in early February, 2022, associated with the occurrence of moderate magnetic storms. Poorly understood structure of coronal mass ejections (CMEs) caused the magnetic storms at unexpected timing. Better understanding of minor CME structures is therefore necessary for modern space weather forecast. The "up to 50%" enhancement of air drag [...]
Controls on surface warming by winter Arctic moist intrusions in idealized large-eddy simulations
Published: 2022-03-25
Subjects: Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The main energy input to the polar regions in winter is the advection of warm, moist air from lower latitudes. This makes the polar climate sensitive to the temperature and moisture of extra-polar air. Here, we study this sensitivity from an air-mass transformation perspective. We perform simulations of an idealized maritime air mass brought into contact with sea ice employing a three-dimensional [...]