Preprints
Search for science and technology (81 results)
Machine-Learning Approaches for Assessing Aerosol Optical Depth (AOD) in Ghana, West Africa
Published: 2024-01-08
Subjects: Education, Medicine and Health Sciences, Physical Sciences and Mathematics
In the field of environmental health, assessing air pollution exposure has historically posed challenges, primarily due to sparse ground observation networks. To overcome this limitation, satellite remote sensing of aerosols provides a valuable tool for monitoring air quality and estimating particulate matter concentration (PM) at the surface. In this study, we employ two predictive models to [...]
A Systematic Review of Machine Learning Algorithms in Groundwater Level Simulations and Forecasting
Published: 2023-12-29
Subjects: Education, Physical Sciences and Mathematics
Over two billion individuals worldwide rely on subterranean water as their primary reservoir of clean water. Ensuring the sustainable management of this heavily burdened resource necessitates a comprehensive quantitative evaluation of groundwater reserves. This becomes even more critical as water resources face escalating demands resulting from socioeconomic growth, population expansion, and the [...]
Seismic Activities in Ghana: A Systematic Review
Published: 2023-08-08
Subjects: Education, Physical Sciences and Mathematics
Seismic activities pose significant challenges to societies globally. Therefore, it is crucial to understand their occurrence, patterns, and impacts. By studying seismic activities, including earthquakes, researchers can investigate their occurrence, distribution, and characteristics which can provide effective management and risk reduction strategies. The southern part of Ghana is prone to [...]
The climate and environmental determinants of domestic water supply change at the Nasia catchment in Northern Ghana
Published: 2023-06-23
Subjects: Geography
The Nasia river serves as the primary source of domestic water supply for over 5000 households in the Nasia catchment. However, the river is currently experiencing water stress conditions, causing an imbalance between the demand for water and the available supply. In this study, we evaluated the impact of climate and environmental factors on changes in domestic water supply in the Nasia [...]
Different mechanisms of Arctic first-year sea-ice ridge consolidation observed during the MOSAiC expedition
Published: 2023-05-10
Subjects: Earth Sciences, Glaciology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Sea-ice ridges constitute a large fraction of the ice volume in the Arctic Ocean, yet we know little about the evolution of these ice masses. Here we examine the thermal and morphological evolution of an Arctic first-year sea-ice ridge, from its formation to advanced melt. Initially the mean keel depth was 5.6 m and mean sail height was 0.7 m. The initial rubble macroporosity (fraction of [...]
In-situ frictional behavior of subducting sediment in the shallow Nankai Trough
Published: 2023-04-22
Subjects: Geology, Geophysics and Seismology, Sedimentology, Tectonics and Structure
The transition from smectite to illite at around the depth with temperature of ~150 °C has long been hypothesized as one of controlling factors of the updip limit depth of the seismogenic zone of subduction zones. Although illite has a higher friction coefficient than smectite, previous friction experiments have little reported that the smectite-illite transition accompanies the transition from [...]
False positives are common in single-station template matching
Published: 2023-02-17
Subjects: Earth Sciences, Geophysics and Seismology, Planetary Geophysics and Seismology, Planetary Sciences
Template matching has become a cornerstone technique of observational seismology. By taking known events, and scanning them against a continuous record, new events smaller than the signal-to-noise ratio can be found, substantially improving the magnitude of completeness of earthquake catalogues. Template matching is normally used in an array setting, however as we move into the era of planetary [...]
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 [...]
The nature of the proximal volcaniclastic materials from the 2021 eruption Fukutoku-Oka-no-Ba in the Izu-Bonin arc.
Published: 2023-01-31
Subjects: Earth Sciences, Geology, Volcanology
Fukutoku-Oka-no-Ba is a submarine volcano located at 24°17.1′N/141°28.9′E in the Izu–Bonin–Mariana arc, and is one of the most active volcanoes in Japan. This volcano produced an explosive eruption in August 2021 that generated a large amount of volcaniclastic material, some of which drifted westward to Japan and the coastal area of East Asia as a pumice raft. The pumice clasts that drifted for [...]
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 [...]
Weakening of the Indian Ocean Dipole in the mid-Holocene due to the mean oceanic climatology change
Published: 2023-01-11
Subjects: Atmospheric Sciences, Climate, Meteorology, Oceanography
The Indian Ocean Dipole (IOD) is one of the leading modes of interannual climate variability in the tropical Indian Ocean (IO). Paleoclimate provides real climate scenarios to examine IOD behaviors and the linkage to basic states. Based on 18 models from the Paleoclimate Modelling Intercomparison Project phase 3 and 4 (PMIP 3/4), the IOD change from the preindustrial period to mid-Holocene is [...]
Thermal stratification and meromixis in four dilute temperate zone lakes
Published: 2022-12-14
Subjects: Life Sciences, Physical Sciences and Mathematics
Four adjacent lakes (Arco, Budd, Deming, and Josephine) within Itasca State Park in Minnesota, USA are reported to be meromictic in the scientific literature. However, seasonally persistent chemoclines have never been documented. We collected seasonal profiles of temperature and specific conductance and placed temperature sensor chains in two lakes for ~ 1 year to explore whether these lakes [...]
Spatial variation in shallow slow earthquake activity in Hyuga-nada, southwest Japan
Published: 2022-10-28
Subjects: Geophysics and Seismology
Hyuga-nada, off the Pacific coast of Kyushu along the Nankai Trough in southwest Japan, is one of the most active slow earthquake regions around Japan. We estimated the energies of shallow tremors and moments of shallow very low frequency earthquakes (VLFEs) in Hyuga-nada using data from a permanent onshore broadband network and temporary ocean bottom seismometer observations. The energies and [...]
Data mining by watching old documentary TV programs to learn about the relationships between people’s lives and the landscape in Sakha in the perestroika era at the end of the 1980s
Published: 2022-08-14
Subjects: Geography
To accurately evaluate the spatiotemporal variability of ecosystem functions and services, as well as biodiversity, under a rapidly changing climate and shifting anthropogenic activities, it is an important but challenging task to retrieve information about past relationships among society, people’s lives, and the landscape. We watched documentary TV programs broadcast by the Japanese public [...]
Evaluation of preservation protocols for oxygen-sensitive minerals within laminated aquatic sediments
Published: 2022-07-25
Subjects: Biogeochemistry, Environmental Sciences, Geochemistry, Sedimentology
Laminated sediments can record seasonal changes in sedimentation of material from anoxic waters, including minerals of the redox-sensitive elements Fe, Mn, and S that form under varying oxygen levels, mineral saturation conditions, and from microbial metabolism. However, preserving both the oxygen-sensitive minerals for identification is challenging when preservation of the spatial arrangement of [...]