The California state Department of Water Resources has started using laser and sonar technology to measure reservoir capacity, determining that Lake Oroville, the State Water Project's largest reservoir, has shrunk since its creation in 1960.
Melting Arctic glaciers are in rapid recession, and microscopic organisms colonize the newly exposed landscapes. Dr. James Bradley, Honorary Reader in Arctic Biogeochemistry in the School of Biological and Behavioral Sciences at Queen Mary University of London, and his team, have revealed that yeasts play an important role in soil formation in the Arctic after glaciers have melted away.
Brief communication: Lessons learned and experiences gained from building up a global survey on societal resilience to changing droughts
Marina Batalini de Macedo, Marcos Roberto Benso, Karina Simone Sass, Eduardo Mario Mendiondo, Greicelene Jesus da Silva, Pedro Gustavo Câmara da Silva, Elisabeth Shrimpton, Tanaya Sarmah, Da Huo, Michael Jacobson, Abdullah Konak, Nazmiye Balta-Ozkan, and Adelaide Cassia Nardocci
Nat. Hazards Earth Syst. Sci., 24, 2165–2173, https://doi.org/10.5194/nhess-24-2165-2024, 2024
With climate change, societies increasingly need to adapt to deal with more severe droughts and the impacts they can have on food production. To make better adaptation decisions, drought resilience indicators can be used. To build these indicators, surveys with experts can be done. However, designing surveys is a costly process that can influence how experts respond. In this communication, we aim to deal with the challenges encountered in the development of surveys to help further research.
The impact of long-term changes in ocean waves and storm surge on coastal shoreline change: a case study of Bass Strait and south-east Australia
Mandana Ghanavati, Ian R. Young, Ebru Kirezci, and Jin Liu
Nat. Hazards Earth Syst. Sci., 24, 2175–2190, https://doi.org/10.5194/nhess-24-2175-2024, 2024
The paper examines the changes in shoreline position of the coast of south-east Australia over a 26-year period to determine whether changes are consistent with observed changes in ocean wave and storm surge climate. The results show that in regions where there have been significant changes in wave energy flux or wave direction, there have also been changes in shoreline position consistent with non-equilibrium longshore drift.
An easy-to-use water vapor sampling approach for stable isotope analysis using affordable membrane valve multi-foil bags
Adrian Dahlmann, John D. Marshall, David Dubbert, Mathias Hoffmann, and Maren Dubbert
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2024-43,2024
Preprint under review for AMT (discussion: open, 0 comments)
Water-stable isotopes are commonly used in hydrological and ecological research. Until now, measurements were obtained either destructive or directly in the field. Here, we present a novel, affordable, and easy-to-use approach to measure the stable isotope signatures of soil water. Our gas bag approach demonstrates a high accuracy and extends the usability by allowing water vapor samples to be collected and stored in the field without the need for an instrument or a permanent power supply.
Lidar–radar synergistic method to retrieve ice, supercooled water and mixed-phase cloud properties
Clémantyne Aubry, Julien Delanoë, Silke Groß, Florian Ewald, Frédéric Tridon, Olivier Jourdan, and Guillaume Mioche
Atmos. Meas. Tech., 17, 3863–3881, https://doi.org/10.5194/amt-17-3863-2024, 2024
Radar–lidar synergy is used to retrieve ice, supercooled water and mixed-phase cloud properties, making the most of the radar sensitivity to ice crystals and the lidar sensitivity to supercooled droplets. A first analysis of the output of the algorithm run on the satellite data is compared with in situ data during an airborne Arctic field campaign, giving a mean percent error of 49 % for liquid water content and 75 % for ice water content.
Understanding the dynamics of rainfall-runoff in mountainous terrains is vital for refining predictions of sediment-related hazards, which are becoming increasingly critical under the influence of climate change. Despite extensive flood monitoring in various mountainous locales globally, comprehensive data from areas characterized by high-relief have been limited primarily to smaller watersheds, typically under 1 km2, featuring moderate river discharges. Meso-scale watersheds, spanning approximately 1–10 km2 and noted for their steep gradients and substantial sediment and water flows, present substantial data collection challenges.
Severe wildfires increase with a decrease in prescribed burns—but new research shows that in some places across the United States there may be fewer opportunities to safely burn in the future.
With record rainfall projected to continue into the future, many worry extreme flooding will follow suit. But a new CIRES-led study published today in Science of the Total Environment found an increase in precipitation alone won't necessarily increase disastrous flooding—instead, flood risk depends on how many days have passed between storms.
A team of physicists, geologists and signal theorists from the University of Granada, Spain, has developed a machine-learning-based algorithm designed to predict when Mount St. Helens will erupt.
Catchment-scale assessment of drought impact on environmental flow in the Indus Basin, Pakistan
Khalil Ur Rahman, Songhao Shang, Khaled Saeed Balkhair, Hamza Farooq Gabriel, Khan Zaib Jadoon, and Kifayat Zaman
Nat. Hazards Earth Syst. Sci., 24, 2191–2214, https://doi.org/10.5194/nhess-24-2191-2024, 2024
This paper assesses the impact of drought (meteorological drought) on the hydrological alterations in major rivers of the Indus Basin. Threshold regression and range of variability analysis are used to determine the drought severity and times where drought has caused low flows and extreme low flows (identified using indicators of hydrological alterations). Moreover, this study also examines the degree of alterations in river flows due to drought using the hydrological alteration factor.
Hydrometeorological controls of and social response to the 22 October 2019 catastrophic flash flood in Catalonia, north-eastern Spain
Arnau Amengual, Romu Romero, María Carmen Llasat, Alejandro Hermoso, and Montserrat Llasat-Botija
Nat. Hazards Earth Syst. Sci., 24, 2215–2242, https://doi.org/10.5194/nhess-24-2215-2024, 2024
On 22 October 2019, the Francolí River basin experienced a heavy precipitation event, resulting in a catastrophic flash flood. Few studies comprehensively address both the physical and human dimensions and their interrelations during extreme flash flooding. This research takes a step forward towards filling this gap in knowledge by examining the alignment among all these factors.
Improving ensemble data assimilation through Probit-space Ensemble Size Expansion for Gaussian Copulas (PESE-GC)
Man-Yau Chan
Nonlin. Processes Geophys., 31, 287–302, https://doi.org/10.5194/npg-31-287-2024, 2024
Forecasts have uncertainties. It is thus essential to reduce these uncertainties. Such reduction requires uncertainty quantification, which often means running costly models multiple times. The cost limits the number of model runs and thus the quantification’s accuracy. This study proposes a technique that utilizes users’ knowledge of forecast uncertainties to improve uncertainty quantification. Tests show that this technique improves uncertainty reduction.
Multi-dimensional, Multi-Constraint Seismic Inversion of Acoustic Impedance Using Fuzzy Clustering Concepts
Saber Jahanjooy, Hosein Hashemi, and Majid Bagheri
Nonlin. Processes Geophys. Discuss., https//doi.org/10.5194/npg-2024-12,2024
Preprint under review for NPG (discussion: open, 3 comments)
This manuscript introduces a new method of using the objective function of fuzzy clustering in seismic inversion. Multiple constraints on the data misfit, allow the operator to apply different conditions on the results. The solution is simple. New concepts that are the results of the inversion methods are good sources for interpretation.
Observations of ionospheric disturbances associated with the 2020 Beirut explosion by Defense Meteorological Satellite Program and ground-based ionosondes
Rezy Pradipta and Pei-Chen Lai
Ann. Geophys., 42, 301–312, https://doi.org/10.5194/angeo-42-301-2024, 2024
A large explosion released a significant amount of energy into the Earth's upper atmosphere in Beirut on 4 Aug 2020, generating traveling ionospheric disturbances (TIDs). These TIDs were observed in previous work using GPS total electron content measurements around Beirut. Here, we used measurements from the Defense Meteorological Satellite Program and ionosondes in the Mediterranean to show that the TIDs from the Beirut explosion were able to reach greater distances than previously reported.
Author(s): Xander M. de Wit, Rudie P. J. Kunnen, Herman J. H. Clercx, and Federico Toschi
In many natural and industrial applications, turbulent flows encompass some form of dispersed particles. Although this type of multiphase turbulent flow is omnipresent, its numerical modeling has proven to be a remarkably challenging problem. Models that fully resolve the particle phase are computat…
[Phys. Rev. E 110, 015301] Published Mon Jul 01, 2024
Abstract
Along the I24, I27, and I31 flybys of Io (1999–2001), the Energetic Particle Detector (EPD) onboard the Galileo spacecraft observed localized regions of energetic protons losses (155–1,250 keV). Using back-tracking particle simulations combined with a prescribed atmospheric distribution and a magnetohydrodynamics (MHD) model of the plasma/atmosphere interaction, we investigate the possible causes of these depletions. We focus on a limited region within two Io radii, which is dominated by Io's SO2 atmosphere. Our results show that charge exchange of protons with the SO2 atmosphere, absorption by the surface and the configuration of the electromagnetic field contribute to the observed proton depletion along the Galileo flybys. In the 155–240 keV energy range, charge exchange is either a major or the dominant loss process, depending on the flyby altitude. In the 540–1,250 keV range, as the charge exchange cross sections are small, the observed decrease of the proton flux is attributed to absorption by the surface and the perturbed electromagnetic fields, which divert the protons away from the detector. From a comparison between the modeled losses and the data we find indications of an extended atmosphere on the day/downstream side of Io, a lack of atmospheric collapse on the night/upstream side as well as a more global extended atmospheric component (>1 Io radius). Our results demonstrate that observations and modeling of proton depletion around the moon constitute an important tool to constrain the electromagnetic field configuration around Io and the radial and longitudinal atmospheric distribution, which is still poorly understood.
Abstract
The statistics of day-to-day tidal variability within 35-day running mean windows is obtained from Michelson Interferometer for Global High-Resolution Thermospheric Imaging (MIGHTI)/Ionospheric Connection Explorer (ICON) observations in the 90–107 km height region for the year 2020. Temperature standard deviations for 18 diurnal and semidiurnal tidal components, and for four quasi-stationary planetary waves are presented, as function of latitude, altitude, and day-of-year. Our results show that the day-to-day variability (DTDV) can be as large as 70% of the monthly mean amplitudes, thus providing a significant source of variability for the ionospheric E-region dynamo and hence for the F-region plasma. We further validate our results with COSMIC-2 ionospheric observations and present an approach to extend the MIGHTI/ICON results to all latitudes using Hough Mode Extension fitting, to produce global tidal fields and their statistical DTDV that are suitable as lower boundary conditions for nudging and ensemble modeling of TIE-GCM. In the future, this will likely help to establish a data-driven perspective of space weather variability caused by the tidal weather of the lower atmosphere.
Abstract
The Earth's magnetosphere is filled with a collisionless plasma that exhibits non-Maxwellian particle distributions which are well described by Kappa functions. In contrast to the Maxwellian, the Kappa contains not only density and temperature but also the kappa index that allows us to characterize the energetic tails. In this study, we analyze the response of the ion and electron Kappa distributions, obtained by fitting ion and electron fluxes measured by the five THEMIS satellites, to changes of the solar wind dynamic pressure. It was found that the solar wind dynamic pressure strongly affects the values of the kappa index, and that its impact depends on the magnetic local time (MLT). In particular, there is a significant dawn-dusk asymmetry for low P
SW
values which is enhanced in the night side. Further, we observe a narrow partial ring-shaped structure at different azimuthal extension that divides the plasma into two clearly defined domains. The results obtained reflect the global reconfiguration of the magnetosphere caused by variations of the solar wind dynamic pressure. Kappa distribution parameters and their average values for different ranges of P
SW
and MLT are provided, which we believe will contribute as realistic inputs to the modeling of the magnetosphere.
Abstract
In the present study, the influence of the solar wind dynamic pressure on the plasma and magnetic pressures of the magnetosphere is studied. We use 11-year Time History of Events and Macroscale Interactions during Substorms (THEMIS) instruments for plasma and magnetic field measurements in the magnetosphere and the OMNI database for solar wind dynamic pressure and IMF data. We focus on the effects of the solar wind dynamic pressure (P
SW
) and consider only times in which the interplanetary magnetic field (IMF) components are within ±5 nT. We find that the plasma pressure inside the magnetosphere follows the solar wind dynamic pressure and that an increase in P
SW
also influence the day-night pressure asymmetry. Our analysis also reveals the existence of ion and electron drifts from midnight toward the dusk and dawn sectors, respectively. We observe a local magnetic pressure minimum located near a plasma pressure maximum at around 11 R
E
on the nightside. Comparing the effect of P
SW
on both plasma and magnetic pressures, we observe trends which are consistent with the diamagnetic properties of plasmas. In general, the distribution of plasma pressure within the Earth's magnetosphere is an important criterion for evaluating the magnetostatic equilibrium and electric current system. The outcome of this study should provide additional methodologies for the characterization of key plasma characteristics within the magnetosphere.
