Preprints
Filtering by Subject: Physical Sciences and Mathematics
New methods for predicting the start and other features of the UK (Northern Hemisphere) Sporadic E (Es) radio propagation season
Published: 2025-06-22
Subjects: Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The sporadic E mode of propagation is briefly described and reviewed. The question is posed could we ever predict the start and duration of the main propagation season. A new hypothesis is proposed based on the modulation of planetary weather and wave circulations and their effect on the Es
Changes in stratiform heating structure due to surface warming weaken and accelerate convectively coupled Kelvin waves
Published: 2025-06-20
Subjects: Physical Sciences and Mathematics
Although stratiform heating plays a crucial role in tropical convective systems, we do not fully understand (1) how stratiform heating would change in response to surface warming and (2) how those changes would affect convectively-coupled equatorial waves. This study analyzes the changes in stratiform heating structure and convectively-coupled Kelvin waves (KWs) associated with surface warming [...]
Maintenance of convectively coupled Kelvin waves: relative importance of internal thermodynamic feedback and external momentum forcing
Published: 2025-06-20
Subjects: Physical Sciences and Mathematics
Previous studies suggest that convectively coupled Kelvin waves (KWs) are likely maintained by two distinct processes: (1) the internal thermodynamic feedback between KW diabatic heating and temperature and (2) the external momentum forcing from the midlatitude Rossby waves exerting on KW zonal wind. This study quantifies the relative importance of the two processes on KW maintenance by comparing [...]
Topographic evidence for recent intraplate reactivation in NW Uruguay
Published: 2025-06-20
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics, Tectonics and Structure
Located in eastern South America, Uruguay has been considered tectonically inactive since rifting in the Late Cretaceous. Here, we use a high-resolution digital elevation model (DEM) and field observations to investigate the presence of recent tectonic activity in the Basaltic Plateau, northwest Uruguay. Based on topographic-, drainage network- and field-based data, we identify evidence for [...]
The Stotfield silcrete (or ‘Stotfield Cherty Rock’), Moray, eastern Scotland: Characterization and discussion of an archaeologically important lithic raw material
Published: 2025-06-18
Subjects: Earth Sciences, Human Geography, Physical Sciences and Mathematics, Social and Behavioral Sciences
We describe and discuss a lithic raw material new to Scottish prehistoric research: the Stotfield silcrete or Stotfield Cherty Rock. This material was well-known to Scottish geologists, but it was only recently realized that it had been used by prehistoric people in Moray, eastern Scotland. We describe our examination of archaeological Stotfield silcrete, as well as field information relating to [...]
Predictability and randomization of surface air temperature chaotic dynamics
Published: 2025-06-18
Subjects: Physical Sciences and Mathematics
The surface air temperature daily records at the land-based locations with different climate conditions (from the Arctic to Patagonia) have been studied on the daily to intraseasonal time scales (low-frequency annual and seasonal variations have been removed by subtracting a wavelet regression from the daily records). It is shown that the power spectra of the daily time series exhibit a universal [...]
The 1993 Jerzmanowice event in Poland and the 1908 Tunguska event
Published: 2025-06-17
Subjects: Education, Physical Sciences and Mathematics
This paper is a continuation of a series of works, devoted to various aspects of the 1908 Tunguska event. In this paper its author would like to draw attention to the phenomenon that is sometimes called the Polish Tunguska in the Polish media, although it would probably be more correct to call it mini-Tunguska. In the evening of January 14, 1993, the village Jerzmanowice (about 20 km NW from [...]
Development and Performance Evaluation of a WT-LSTM Hybrid Model for Global Land Meteorological Drought Prediction
Published: 2025-06-17
Subjects: Engineering, Physical Sciences and Mathematics
In recent years, droughts have become increasingly frequent worldwide, leading to issues such as reduced agricultural yields and ecological degradation in various regions. To mitigate the impact of drought on human survival and development, this study utilizes the Standardized Precipitation Evapotranspiration Index (SPEI) to analyze the spatiotemporal variations of global droughts. The results [...]
Chapter 3.2 - Distributed Volcanic fields
Published: 2025-06-17
Subjects: Physical Sciences and Mathematics
Distributed volcanic fields are typically low magma-flux systems, and occur in every tectonic setting. Their volcanoes are typically but not exclusively small-volume (≤1 km3 of magma). The most typical type of volcanoes associated with volcanic fields include scoria cones, tuff rings, maars, tuff cones, spatter cones, and associated lava flows, in addition to sparse medium-size shields and lava [...]
Simple solar system measurements indicate a weaker than expected relevance of Carbon Dioxide to present day earth temperature.
Published: 2025-06-15
Subjects: Physical Sciences and Mathematics
Recent and newly discovered causes of global warming are discussed especially in the context of lower relevance to CO2. Heat transfer mechanisms are discussed. The link between convective heat transfer and the thermodynamic and planetary hypotheses of Nikolov and Zeller are discussed. It is considered that the maximum surface temperature reached on an airless planetary body ( planet or moon) is [...]
A century of flow and surge history of Sít’ Tlein(Malaspina Glacier), Southeast Alaska
Published: 2025-06-13
Subjects: Earth Sciences, Physical Sciences and Mathematics
Sít' Tlein (Malaspina Glacier), located in Southeast Alaska, has a complex flow history. This piedmont glacier, the largest in the world of its kind, is fed by three main tributaries that all exhibit similar flow patterns, yet with varying surge cycles. The piedmont lobe is dramatically reshaped by surges that occur at approximately decadal timescales. By combining historical accounts with modern [...]
Determination of Low Molecular Weight Organic Acids in Environmental Samples by Ion Chromatography Method
Published: 2025-06-13
Subjects: Life Sciences, Medicine and Health Sciences, Physical Sciences and Mathematics
Ion chromatography using the IonPac AS 11 HC analytical column, a 3.0 mM NaOH eluent, and a conductivity detector offers a straightforward, cost-effective, and rapid method for quantifying six organic acids, Lactate, Formate, Acetate, Propionate, Pyruvate, and Glyoxalate, at concentrations as low as micrograms per liter in environmental samples. The method includes comprehensive details on [...]
Green Hydrogen from Biomass in Kenya: Geospatial Feed-stock Mapping and Decentralized Energy Integration
Published: 2025-06-13
Subjects: Engineering, Physical Sciences and Mathematics
As countries race to decarbonize, green hydrogen has emerged as a crucial clean energy transformation vehicle. In Sub-Saharan Africa, sufficient biomass resource potential exists to become an actual feedstock for decentralised hydrogen production, but under-explored are the spatial mismatches between resource occurrences and infrastructure systems. The paper conducts a geospatial assessment of [...]
Limitations of Mw and M Scales: Compelling Evidence Advocating for the Das Magnitude Scale (Mwg)—A Critical Review and Analysis
Published: 2025-06-12
Subjects: Engineering, Physical Sciences and Mathematics
Abstract Precise determination of earthquake size is cru cial for various geoscientific and engineering applications. The Moment Magnitude (Mw) scale, introduced by Kan amori in 1977, was a significant advancement. Kanamori (1977) advocated use of Mw for large earthquakes (≥ 7.5). (Hanks and Kanamori in J. Geophys. Res. 84:2348–2350) later extended the Mw scale named as M scale by [...]
Comprehensive quantification of production costs for large-scale kelp aquaculture and cost reduction opportunities
Published: 2025-06-12
Subjects: Agriculture, Earth Sciences, Engineering, Environmental Sciences, Life Sciences, Natural Resource Economics, Other Engineering, Physical Sciences and Mathematics
A highly realistic techno-economic analysis (TEA) was developed to assess the cost of production (COP, US $ per fresh tonne kelp) for large-scale kelp aquaculture. The TEA resolves feedbacks across structural design and response, operational requirements and decisions, site properties, and biological response. We apply the TEA to a Saccharina latissima farming operation at a 100m deep, 405 [...]