Preprints
Filtering by Subject: Astrophysics and Astronomy
Diverse Carbonates in Exoplanet Oceans Promote the Carbon Cycle
Published: 2023-12-22
Subjects: Astrophysics and Astronomy, Planetary Geochemistry, Planetary Sciences
Carbonate precipitation in oceans is essential for the carbonate-silicate cycle (inorganic carbon cycle) to maintain temperate climates. By considering the thermodynamics of carbonate chemistry, we demonstrate that the ocean pH decreases by approximately 0.5 for a factor of 10 increase in the atmospheric carbon dioxide content. The upper and lower limits of ocean pH are within 1-4 of each other, [...]
Exclusive Seismoacoustic Detection and Characterization of an Unseen and Unheard Fireball Over the North Atlantic
Published: 2023-08-08
Subjects: Astrophysics and Astronomy, Earth Sciences, Physical Sciences and Mathematics
Small meteoroids that enter Earth's atmosphere often go unnoticed because their detection and characterization rely on human observations, introducing observational biases in space and time. Acoustic shockwaves from meteoroid ablation convert to infrasound and seismic energy, enabling fireball detection using seismoacoustic methods. We analyzed an unreported fireball in 2022 near the Azores, [...]
Numerical simulation of meteorite impact on basaltic lavas at Lonar Crater, India
Published: 2023-01-28
Subjects: Applied Mathematics, Astrophysics and Astronomy, Planetary Sciences
Lonar lake is a hypervelocity impact crater formed in a basaltic terrain of Deccan Traps in the state of Maharashtra, India. The crater has an approximate radius of 915 m and an average depth of about 137 m. Here we report the results of our numerical investigations aimed to elucidate the physical characteristics of incoming asteroid. For realistic simulation, we not only consider [...]
Thermal evolution of rocky exoplanets with a graphite outer shell
Published: 2022-01-18
Subjects: Astrophysics and Astronomy, Planetary Sciences
The presence of rocky exoplanets with a large refractory carbon inventory is predicted by chemical evolution models of protoplanetary disks of stars with photospheric C/O >0.65, and by models studying the radial transport of refractory carbon. High-pressure high-temperature laboratory experiments show that most of the carbon in these exoplanets differentiates into a graphite outer shell. Our aim [...]
An experimental combination of IGS repro3 campaign’s orbit products using a variance component estimation strategy
Published: 2021-10-05
Subjects: Astrophysics and Astronomy, Earth Sciences, Navigation, Guidance, Control and Dynamics, Other Earth Sciences, Other Mathematics
Over the past years, the International GNSS Service (IGS) has put efforts into reprocessing campaigns reanalyzing the full data collected by the IGS network since 1994. The goal is to provide a consistent set of orbits, station coordinates, and earth rotation parameters using state-of-the-art models. Different from the previous campaigns - namely: repro1 and repro2 - the repro3 includes not only [...]
Orbital, the Box - An interactive educational tool for in-depth understanding of astronomical climate forcing.
Published: 2021-04-07
Subjects: Adult and Continuing Education, Astrophysics and Astronomy, Climate, Earth Sciences, Education, Educational Methods, Geology, Geophysics and Seismology, Higher Education, Instructional Media Design, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, The Sun and the Solar System
“Orbital, the Box” provides an interactive tool with graphical user interface (GUI) for stimulating active, visual learning for understanding of astronomical climate forcing. This cross-platform tool can be run locally on a personal computer using a standard web browser environment with no need for plugins, thus maximising accessibility for students and teachers alike. The tool facilitates in the [...]
Lithologic Controls on Silicate Weathering Regimes of Temperate Planets
Published: 2021-03-12
Subjects: Astrophysics and Astronomy, Earth Sciences, Geochemistry, Planetary Geochemistry, Planetary Sciences
Weathering of silicate rocks at a planetary surface can draw down CO2 from the atmosphere for eventual burial and long-term storage in the planetary interior. This process is thought to provide essential negative feedback to the carbonate-silicate cycle (carbon cycle) to maintain clement climates on Earth and potentially similar temperate exoplanets. We implement thermodynamics to determine [...]
The precession constant and its long-term variation
Published: 2020-12-08
Subjects: Astrophysics and Astronomy, Earth Sciences, Physical Sciences and Mathematics, Planetary Sciences
The dynamical flattening of the Earth, H, related to the precession constant, is a fundamental astro-geodetic parameter that appears in studies of the Earth's rotation and orbital evolution. We present numerical predictions and observations of the variation in H over time scales ranging from tens of millions of years to decades. The geophysical processes controlling this variation include [...]
A prototype for a Multi-GNSS orbit combination
Published: 2020-08-20
Subjects: Astrophysics and Astronomy, Earth Sciences, Other Astrophysics and Astronomy, Other Earth Sciences, Physical Sciences and Mathematics
Since 1994, the International GNSS Service (IGS) provides a combination of orbit and clock offset products from its different Analysis Centers. These products are used as input by many software for countless scientific and/or operational applications. They can also be used as an independent reference for benchmark experiments. Nevertheless, those products include GPS-only data, despite the fact [...]
Estimating survival probability using the terrestrial extinction history for the search for extraterrestrial life
Published: 2020-07-21
Subjects: Astrophysics and Astronomy, Earth Sciences, Physical Sciences and Mathematics, Planetary Sciences
Several exoplanets have been discovered to date, and the next step is the search for extraterrestrial life. However, it is difficult to estimate the number of life-bearing exoplanets because our only template is based on life on Earth. In this paper, a new approach is introduced to estimate the probability that life on Earth has survived from birth to the present based on its terrestrial [...]
Habitability of the early Earth: Liquid water under a faint young Sun facilitated by strong tidal heating due to a nearby Moon
Published: 2020-07-10
Subjects: Astrophysics and Astronomy, Earth Sciences, Other Astrophysics and Astronomy, Other Earth Sciences, Physical Sciences and Mathematics, Planetary Sciences, The Sun and the Solar System
Geological evidence suggests liquid water near the Earths surface as early as 4.4 gigayears ago when the faint young Sun only radiated about 70 % of its modern power output. At this point, the Earth should have been a global snowball. An extreme atmospheric greenhouse effect, an initially more massive Sun, release of heat acquired during the accretion process of protoplanetary material, and [...]
Detection of VLF attenuation in the Earth-ionosphere waveguide caused by X-class solar flares using a global lightning location network
Published: 2020-01-09
Subjects: Astrophysics and Astronomy, Earth Sciences, Geophysics and Seismology, Other Physics, Physical Sciences and Mathematics, Physics, The Sun and the Solar System
Solar flares, energetic particles and Earth-impacting coronal mass ejections enhance ionization in the lower ionosphere, inhibiting radio wave propagation in the Earth-ionosphere waveguide (EIWG). This enhanced ionization is observed locally by ionosondes and GPS/GNSS receivers, but spatial coverage of these observations is limited by receiver location. VLF propagation studies have previously [...]
Linking the evolution of terrestrial interiors and an early outgassed atmosphere to astrophysical observations
Published: 2019-10-16
Subjects: Astrophysics and Astronomy, Earth Sciences, Geophysics and Seismology, Other Astrophysics and Astronomy, Physical Sciences and Mathematics, Planetary Geophysics and Seismology, Planetary Sciences
A terrestrial planet is molten during formation and may remain molten due to intense insolation or tidal forces. Observations favour the detection and characterisation of hot planets, potentially with large outgassed atmospheres. We aim to determine the radius of hot Earth-like planets with large outgassing atmospheres. Our goal is to explore the differences between molten and solid silicate [...]
Causation of Late Quaternary Rapid-increase Radiocarbon Anomalies
Published: 2019-05-07
Subjects: Astrophysics and Astronomy, Cosmochemistry, Earth Sciences, Physical Sciences and Mathematics
Brief (<100 y) rapid-increase anomalies in the Earth’s atmospheric 14C production have previously been attributed to either gamma photon radiation from supernovae or to cosmic ray particle radiation from exceptionally large solar flares. Analysis of distances and ages of nearby supernovae (SNe) remnant surveys, the probable gamma emissions, the predicted Earth-incident radiation, and the [...]
Decomposition of Amino Acids in Water with Application to In-Situ Measurements of Enceladus, Europa and Other Hydrothermally Active Icy Ocean Worlds
Published: 2019-04-17
Subjects: Astrophysics and Astronomy, Physical Sciences and Mathematics, Planetary Biogeochemistry, Planetary Geochemistry, Planetary Sciences, The Sun and the Solar System
To test the potential of using amino acid abundances as a biosignature at icy ocean worlds, we investigate whether primordial amino acids (accreted or formed by early aqueous processes) could persist until the present time. By examining the decomposition kinetics of amino acids in aqueous solution based on existing laboratory rate data, we find that all fourteen proteinogenic amino acids [...]