This paper presents a novel hybrid deterministic-stochastic river morphodynamics numerical modeling approach that integrates a two-dimensional (2D) hydrodynamic model (deterministic) with a bed morphodynamic model (deterministic) and a bank erosion model (Markovian stochastic). The model solves the 2D Shallow Water Equations and the standard k-epsilon turbulence model. Bedload transport is estimated using the Meyer-Peter and Muller formula, and bed evolution is solved using the Exner Equation. The Markovian stochastic bank erosion model uses a new method to evaluate bank erosion risk. The approach was applied to a meander bend cutoff event in the Maiqu River on the Tibetan Plateau. Sixteen different bank-material critical shear stress cases were considered, representing highly erodible banks to resistant banks. Ten statistical realizations were performed for each case with different bank-material erodibility to obtain ensemble-averaged results. Flow field and bed evolution in the cutoff channel suggest that the model can successfully simulate bank erosion processes during the cutoff channel evolution, and bank topographic irregularities are reasonably captured. A newly introduced calibration parameter, the ratio of mesh size to the coupling period between the bank erosion model and the hydrodynamic & morphodynamic model, is not as intuitive as the erosion resistance calibration parameters used by the traditional bank erosion model. The proposed approach necessitates estimating the size of a typical slump failure, or 10-30% of the cutbank height, to set the size of the computational mesh.

Tomorrow.io operates a near-global, near-real time precipitation retrieval framework that extends coverage beyond traditional radar networks. This manuscript details the development and operationalization of the product's third generation, which is currently available with a refresh rate of 5 minutes and spatial resolution of 0.04° (~4 km), covering latitudes between 60°S and 72°N. Precipitation estimates are derived from a convolutional neural network that ingests observation sequences from multi-channel geostationary imagers and orbiting microwave sounders within the preceding hour. The network is trained to handle sparse data from individual instruments, delivering a spatially-complete retrieval that approximates real-time conditions. Our results demonstrate that this third generation of the Tomorrow.io near-global precipitation product improves categorical and continuous precipitation metrics by 5-10% over the previous generation, with significantly larger skill improvements over publicly available near real-time alternatives such as IMERG-Early. Verification was performed against terrestrial radar networks (USA, Europe, Japan, Brazil, and Australia) using test datasets spanning all seasons and against gauge observation networks for several case studies outside the training domains. Additionally, case studies of retrievals in impactful hurricanes during 2024 and recent operational results demonstrate the impact of incorporating microwave sounder data from two recently launched instruments in Tomorrow.io's constellation. These instruments provide more direct observations of precipitation processes than the geostationary imagers, which the network leverages to further enhance skill beyond the third-generation product's elevated baseline. The Tomorrow.io satellite constellation and precipitation retrieval framework benefit near-real time weather applications in aviation, agriculture, hazard preparedness, water resource management, and other sectors at global scales.

Understanding the fate of microplastics (MPs) in soil is one of the most urgent environmental tasks we face. It is also a very challenging one, as there are numerous properties of both MPs and the soil, as well as hydrological and geochemical conditions, that interplay to affect MPs transport. In this study, we conduct laboratory experiments in which two of the most commonly used MPs types in agriculture (polyethylene terephthalate (PET) and polypropylene (PP)) are leached into an idealized soil analog (glass beads). We find that MPs inhibit water flow, delaying its passage through the sample and making it more tortuous, forcing the flow to occur through preferential pathways (fingers). These effects are more pronounced for PP, which is more hydrophobic, than for PET. The transport of PP is inhibited relative to that of PET, which is attributed to its both its impeding effect on water flow (the driving force), as well as its surface charge which increases its tendency to adsorb onto soil particles, and lower density which curbs downward transport.

A document by Sophia Rodrigues Laranja. Click on the document to view its contents.

Previous work has pointed to the physical mechanisms behind the nocturnal offshore propagation of convection south-west of Sumatra. Low-level moisture flux convergence due to the land breeze front controls the progression of a squall line away from the coast overnight. However, the diurnal convection over the mountains occurs on only 57% of days in December-February (DJF) and propagates offshore on only 49% of those days. We investigate day-to-day variability in dynamical and thermodynamical conditions to explain the variability in diurnal convection and offshore propagation, using a convection-permitting simulation run for 900 DJF days. A convolutional neural network is used to identify regimes of diurnal cycle and offshore propagation behaviour. The diurnal cycle and offshore propagation are most likely to occur ahead of an active Madden-Julian Oscillation, or during El Niño or positive Indian Ocean Dipole; however, any regime can occur in any phase of these large-scale drivers, since the major control arises from the local scale. When the diurnal cycle of convection occurs, low-level wind is generally onshore, providing convergence over the mountains; and low-level humidity over the mountains is high enough to make the air column unstable for moist convection. When this convection propagates offshore, mid-level offshore winds provide a steering flow, combined with stronger convergence offshore due to the land breeze or convection-triggered cold pools. Low-level moisture around the coast also means that, as the convection propagates, the storm-relative inflow of air into the system adds greater instability than would be the case on other days.

Geomagnetic disturbances (GMDs) are rapid fluctuations in the strength and direction of the magnetic field near the surface of the Earth which can cause electric currents to be induced in the ground. The geomagnetically induced currents (GICs) can cause damage to pipelines and power grids. A detection algorithm has been developed to identify rapid changes in 10 second averaged magnetometer data. This higher resolution data is important in capturing the most rapid changes associated with extreme GIC events. The algorithm has been used on an array of ground-based magnetometers from SuperMAG data from 2010 to 2022, creating a new list of global GMDs. Data from the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) is used to place the observed GMDs in the context of the global pattern of magnetosphere-ionosphere field-aligned currents (FACs). A dawn sector population of GMDs is found to lie near the boundary between the region 1 and region 2 FACs, while a pre-midnight sector population is found to occur poleward of the FAC boundary on region 1 upward FACs. It is also shown that the latitude of the GMDs expands with the FAC boundary and their occurrence peaks around 77 degrees magnetic latitude.

In this study, we show that non-thermal collisions can play a significant role in shaping Europa's exospheric structure. Collisions between radiolytically produced O2 and the O produced via electron impact dissociation of O2 play a significant role in affecting the exospheric structure and escape rates. Specifically, O+O2 collisions lead to the production of a non-thermal O2 population, and increase the O2 escape while decreasing the O escape. These collisions are dependent on three specific physical parameters: (1) the density of O2 , (2) the electron impact dissociation rate of O2 , and (3) the O+O2 collision cross section. We demonstrate here that O+O2 collisions affect Europa's atmosphere even in the lowest limits considered. Thus, to more accurately determine the influence O+O2 collisions have on Europa's atmosphere in preparation for the forthcoming spacecraft missions, Europa Clipper and the JUpiter ICy moons Explorer (JUICE), these physical parameters need to be better constrained.

 Wide convective cell depth responds most to available instability, while narrow cell depth responds most to mid-level relative humidity.  Entrainment-driven reduction of buoyancy decreases as updraft width increases, causing disparate narrow and wide cell depth responses.  A convection-permitting simulation with 3-km horizontal grid spacing generally reproduces observed relationships.

Sorghum elemental content response to altered nitrogen input timing and drought stressBenjamin D. Duval1, Jamie Martin1, Bonnie Frey2, Mark A. Marsalis31Biology Department, New Mexico Institute of Mining and Technology, Socorro, New Mexico 878012New Mexico Bureau of Geology and Mineral Resources, Socorro, New Mexico, 878013Los Lunas Agricultural Science Center, New Mexico State University, Los Lunas, New Mexico 87031*corresponding author: benjamin.duval@nmt.eduAuthor contributionsBDD: conceived of study, field sampling, data analysis/interpretation, manuscript preparationJM: field sampling, laboratory analysis, manuscript editingBF: laboratory oversight (ICP-MS/OES), laboratory analysis, manuscript editingMAM: farm infrastructure, field experiment monitoring/management, sample collection, manuscript editing

Positions of earthquakes over 5th magnitude were investigate in Taiwan region and adjacent Philippine Sea Plate. Purpose of this paper was to establish earthquakes tidal periods in range of Moon sidereal rotation cycle. Because sidereal Moon cycle reflects variation in length of day of Earth, positions of earthquakes on this graph stated positions on Moon’s orbit and from it followed the tidal frequences knowing time. 849 earthquakes after declusterization were investigated in three time periods 1962-1982, 1983-2002 and 2003-2024. Histograms of earthquakes compiled for Moon crossing equator from south, reaching maximum Moon declination, reaching Moon equator from north and reaching maximum negative declination, presented tidal frequence 6.83 days, 13.66 days and their multiples. By this way stated earthquake occurrence periods are only 31.8 %, but remaining earthquakes have also tidal origin given tectonic position on Taiwan and cumulative action of northsouth and westward directing forces.

Training data: 1.6 million 2x8x8 patches of SAR data randomly sampled from 105 bursts of OPERA RTC-S1; 30m resolution, with two channels: VV (Vertical transmit and Vertical receive) and VH (Vertical transmit and Horizontal receive). Validation Sites: On May 24, 2024, a large landslide in Papua New Guinea buried a village and killed between 650 and 2,000 people. In February 2024, a series of wildfires broke out in the Valparaiso region of Chile. At least 137 people were killed and over 23,000 hectares were burned.

Ionospheric topside O+ diffusive flux is derived using Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) radio occultation data, to investigate its global distribution and also its role in winter nighttime enhancement (WNE) of electron density. The flux of the winter hemisphere maintains downward throughout the night. It is much larger between 30o and 50o geomagnetic latitudes and keeps increasing until 22:00-00:00 LT. It peaks at 60oW and 60oE-120oE geographic longitudes during the December solstice, and at 180oE during the June solstice. These features are similar to those of WNE in NmF2. Furthermore, the derived flux is applied as the upper boundary condition to run the Thermosphere Ionosphere Electrodynamics General Circulation Model (TIEGCM). The simulated spatial-temporal variations of WNE are consistent with the observations. The results indicate that downward plasma diffusion from the plasmasphere is the major mechanism of WNE, and the simulation quantifies its contribution.

It has been widely accepted that channel geometry on alluvial fans is predominantly controlled by upstream boundary conditions and remains stable if those conditions do not change. This study challenges that notion by examining how channel width on alluvial fans varies in space and time under constant upstream conditions. Experiments using a sediment mixture (sand and crushed walnut) with constant sediment and water discharge rates reveal distinct patterns. In lower water discharge runs, total channel width decreases over time, while in higher discharge runs, it increases. Theoretical principles suggest that channel width is inversely proportional to grain size. The disproportional advancement of sand reaches relative to the fan margin, which varies across different discharge runs, drives changes in slope and channel width over time. This study highlights that surface grain-size distribution can change as the fan grows, even when external conditions remain constant, leading to variations in channel geometry.

The use of spherical modes offers an efficient solution for storing embedded element patterns with significant angular structure for large scale arrays, such as the Square Kilometre Array (SKA)-Low radio telescope. These patterns are required for calibration of the numerous stations comprising the telescope, each containing several hundred elements, and operating over a 7:1 bandwidth. However, implementation is significantly complicated by the many differences in the notation used in the literature for the Legendre special functions. The differing phasor conventions used in electrical engineering and physics further complicate this. This paper synthesises much of the existing literature on this topic, paying special attention to these issues. Mathematical implementation issues are also addressed. A number of suitable tests using canonical dipole radiators to verify correct implementation are outlined. The paper concludes with tests on an individual SKALA4 antenna and a full-scale SKA-Low prototype station comprising 256 of these antennas. The storage saving afforded is some three orders of magnitude; this is very significant for a full SKA-Low station. Supporting material addresses some mathematical issues, outlines industry-standard storage schemes and summarises differing conventions encountered in the literature.

Both composition and temperature play a crucial role in determining the NO radiative cooling in lower thermosphere as observed by TIMED/SABER. In this work, we present a detailed investigation of seasonal variation in thermospheric NO radiative cooling. We have carried forward the investigation of [1] regarding the variations in local nighttime peak NO radiative cooling and its altitude during solar maximum and solar minimum conditions. By analyzing latitudinal changes over quiet times for each month in year 2018, it is evident that both the investigative parameters exhibit summer-winter variability. The qualitative contribution of different species (i.e., NO, and O), and temperatures in determining the vertical profile of NO radiative cooling for different latitudes is investigated by utilizing the NRLMSISE-00 estimated parameters, and SNOE observed NO density. The temperature, NO density, meridional wind, and associated compositional variations due to asymmetrical solar heating in both the hemispheres during solar minimum conditions seem to be the dominating factor in controlling the NO radiative cooling during different seasons. The altitudes at which maximum cooling by NO occurs exhibits an inverse correlation with the amount of radiative cooling. The region of enhanced NO densities (polar and summer hemispheric low-mid latitude regions) have larger NO radiative cooling with lower peak altitudes in comparison to other regions (equatorial to winter hemispheric low-mid latitude regions), where NO radiative cooling is low with higher peak altitude values.

Subsurface characterization remains a pivotal challenge in geology, hindered by the inherent complexity and nonstationarity of geological processes. Conventional geostatistical methods, relying on two-point statistics and kriging, often fall short in capturing the spatial heterogeneity and transitional dynamics of subsurface materials. This study introduces a novel three-dimensional lithofacies characterization method that incorporates manifold embedding and a transition probability-based spatial estimation technique, significantly deviating from conventional approaches. The proposed method addresses existing limitations by providing a robust framework for capturing the nonstationary nature of geological processes, utilizing data such as pole-to-plane orientations and lithological transitions for structural and juxtapositional information. Through hypothetical scenarios and simulations, the performance of the proposed method is demonstrated, showcasing its capability to model complex geological formations and accurately estimate subsurface characteristics. The study underscores the importance of considering nonstationarity in geological estimations and highlights the potential impact on hydrogeological modeling. Accurate lithological distribution estimation is crucial for reliable groundwater flow and solute transport modeling. This study advances the methodological toolkit for subsurface characterization and paves the way for future research, including empirical validation with real-world data and exploration of the method's applicability in early-stage site characterization, where data scarcity and quality are pressing concerns.

A document by Zhongzheng Wang. Click on the document to view its contents.

Incoherent scatter radar measurements rely on the application of a priori parameters from empirical models to initialize the analysis of incoherent scatter spectra. Currently, there is a need to transform ionosphere models to enable reliable space weather predictions through data assimilation of observations. Very often the data assimilation relies on electron densities measured with incoherent scatter radars. Erroneous a priori parameters would lead to the assimilation of flawed and physically inconsistent data depending on the ionospheric model. It might therefore be beneficial to assimilate the entire radar spectrum and infer the plasma parameters from the assimilated spectrum by applying the a priori parameters as given by the model. To assess the potential assimilation of incoherent scatter spectra into models, we investigate synthetic EISCAT incoherent scatter spectra calculated from TIE-GCM results. At F1 region altitudes, the atomic-to-molecular ion ratio strongly affects the shape of the incoherent scatter spectrum. Since the vertical profiles of the atomic-to-molecular ion ratio are distinctly different in the EISCAT a priori model and TIE-GCM, the assimilation of single plasma parameters induces additional, unbalanced forces into the model. A similar problem arises in the E region due to different ion-neutral collision frequency profiles. These problems could be solved by assimilation of the entire incoherent scatter spectrum followed by an in-model evaluation of the plasma parameters. We demonstrate the effect of different a priori profiles on the spectral analysis and how the derived plasma parameters are changing when leveraging a more comprehensive approach of using forward modeling with TIE-GCM.