We present an analysis of in-situ thermal ion measurements from a cusp auroral sounding rocket. Using a forward modeling procedure, we find most-probable thermal ion temperature and parallel (field-aligned) bulk flow velocity along the trajectory. Spatially and temporally intermittent fine-scale structure in upflowing/downflowing features in the dayside cusp ionosphere are presented. We show that the observed ion temperatures are consistent with Joule heating expectations if spatially and temporally intermittent drivers and responses in the dynamic cusp environment are considered. Additionally, a forward modeling procedure for the ion data interpretation is improved and a sensitivity analysis is presented.

In volcanic islands, a crucial step in managing watershed water resources is the characterization of groundwater aquifers from local to regional scales. Airborne geophysical data provide high-resolution images down to hundreds of meters below the surface, over large areas. Yet, the production of an accurate interpretation of regional geophysical imagery may be time consuming or limited by the low density of geological and hydrological field observations. Here, we propose an approach combining airborne electromagnetic and magnetic data in order to reduce geophysical ambiguities and provide a multiscale hydrogeophysical characterization of Piton des Neiges volcano (Réunion Island). With limited calibration data, this methodology produces a geological model more accurate than using airborne electromagnetic data alone. Through the continuous coverage of both methods, we demonstrate the influence of volcanic unit geometries on groundwater flows within the critical zone and we highlight major structures impacting groundwater flows at both local and regional scales.

Field survey, satellite image interpretation, geological map interpretation, literature review, GPlates reconstruction and LA-ICP-MS U-Pb dating of synkinematic calcites demonstrate that ~E/W-shortening in eastern Oman was significant and related to oblique convergence of Arabia and India from 32.5 to 20 Ma. Approximately N/S-oriented compressive structures, WNW to NNW-striking sinistral faults and ~E/W-oriented normal faults characterize a major shear zone in the eastern Oman Mountains (Hajar Shear Zone, HSZ) and its wrench-fault assemblage within an area spanning ~250 km x ~50 km. More than 10,000 mostly NW-striking lineaments as deduced from satellite image interpretation and numerous faults/folds indicate that strain of the HSZ is widely distributed but concentrated along WNW to NNW-striking major faults/fault zones at the SW margin of the Saih Hatat Dome. These faults/fault zones represent reactivated basement faults. GPlates reconstructions reveal that N-drifting India rotated 8° counter-clockwise with respect to fixed Arabia from 32.5 to 20 Ma, leading to ~100-135 km E/W-convergence between both plates (minimum value). This convergence created the sinistral HSZ with a displacement of a few to several tens of kilometers. Independently from the GPlates time constraints, two U-Pb ages of synkinematic calcites, crystallized along faults during HSZ movement, yield compatible ages of 30.08 ±0.47 and 22.31 ±2.15 Ma (2 standard error). E/W-shortening also affected the northern Oman Mountains, creating the ~N/S-oriented Hagab Thrust in the Musandam Peninsula and the Jabal Hafit Anticline.

Accurate fog prediction in densely urbanized cities poses a challenge due to the complex influence of urban morphology on meteorological conditions in the urban roughness sublayer. This study implemented a coupled WRF-Urban Asymmetric Convective Model (WRF-UACM) for Delhi, India, integrating explicit urban physics with Sentinel-updated USGS land-use and urban morphological parameters derived from the UT-GLOBUS dataset. When evaluated against the baseline Asymmetric Convective Model (WRF-BACM) using Winter Fog Experiment (WiFEX) data, WRF-UACM significantly improved urban meteorological variables like diurnal variation of 10-meter wind speed, 2-meter air temperature (T2), and 2-meter relative humidity (RH2) on a fog day. UACM also demonstrates improved accuracy in simulating temperature and a significant reduction in biases for RH2 and wind speed under clear sky conditions. UACM reproduced the nighttime urban heat island effect within the city, showing realistic diurnal heating and cooling patterns that are important for accurate fog onset and duration. UACM effectively predicts the onset, evolution, and dissipation of fog, aligning well with observed data and satellite imagery. Compared to WRF-BACM, WRF-UACM reduces the cold bias soon after the sunset, thus improving the fog onset error by ~4 hours. This study underscores the UACM’s potential in enhancing fog prediction, urging further exploration of various fog types and its application in operational settings, thus offering invaluable insights for preventive measures and mitigating disruptions in urban regions.

Pedogenic carbonate is widespread at mid latitudes where combined warm and dry conditions favor soil carbonate growth from spring to fall. The mechanisms and tempo of pedogenic carbonate formation are more ambiguous in the tropics, where longer periods of soil water saturation and higher soil respiration enhance calcite dissolution. This paper provides bulk and clumped isotope values from Quaternary and Miocene pedogenic carbonates in the tropical monsoonal domain of Myanmar where annual rainfall reaches up to 1700 mm. We show that carbonate growth in Myanmar is delayed to the coldest months of the year by sustained rainfall from mid spring to late fall. We propose that high soil moisture year-round in the tropical domain makes carbonate growth more episodic than in temperate ecosystems, and particularly sensitive to the seasonal distribution of rainfall. This sensitivity is also enhanced by high winter temperatures, allowing carbonate growth to occur outside the warmest months of the year. This high sensitivity is expected to be more prominent in the geological record during times with higher temperatures and greater expansion of the tropical realm. The winter bias in TD47 values found in Burmese soils, unique for pedogenic carbonates, constitute a potential signature for past tropical monsoonal (warm summer-wet) climates in paleosols, and are also found in our Miocene samples.

In the call of 2015, the European Geosciences Union funded the workshop “Water as hazard and water as heritage”, to take place in Rome in the consecutive year. The frame for the workshop was given by the “Spazi aperti” (=open spaces) event at the Accademia di Romania a Roma, where the convener (Maria Bostenaru Dan) was a fellow that time on a topic related to water and architecture. Spazi aperti XIV, the edition of 2016, was curated by Roxana Mihaly, former fellow of Accademia di Romania a Roma. The integration reached over the day of oral presentations, as posters of the workshop were displayed in frame of the exhibition in a creative way. Accademia di Romania a Roma opens in frame of Spazi aperti all its spaces, not only the conference room, and the posters were displayed in an underground corridor ending in spaces with related artistic works (for example the convener participated with an installation). The artists invited come from other foreign accademies in Rome, Rome being a city to be visited by scientists from humanities and artists since a number of centuries (“all ways lead to Rome”). This ensured international participation from Europe and beyond. The geosciences were also well represented, which enabled the dialogue between science and the arts. After the talks guided tours were organised to related exhibitions on water in related museums which emphasized the archaeology dimension. Apart of this event there were a number of scientific and musical events accompanying the exhibition, strenghening the dialogue. The event was part of the “month of international culture” in Rome, highly mediatised, and different of the exhibitions of just own fellows in other foreign academies. In 2018 the book was published and is subject of a poster in another session (EGU2019-2000) which all attendees are invited to see. More about the event can be followed on the webpage https://sites.google.com/site/egutopicalevent/

The Java margin is part of the 5600 km long Sunda Arc subduction zone that extends from Sumatra to the Lesser Sunda Islands and is dominated by earthquakes with magnitude less than 7. Although several 7.0 ≤ Mw < 8.0 earthquakes have occurred, there has been an absence of Mw>8. Previous earthquake relocation studies have mainly focused on the ml ≥ 4 earthquakes, while seismic tomography studies have mainly focused on the volcanic system in Central and East Java. In this study, we aim to image the entirety of Java margin to investigate segmentation along this margin. We use the arrival time dataset from 2009 – 2018 collected from 44 stations in the BMKG national seismic network to relocate earthquakes and invert for seismic velocity structure along the Java margin using a finite-difference tomography algorithm. A total of 6041 earthquakes, 68250 P- and 22795 S-phases, ml 1.9 – 7.5, were included in the inversion, resulting in 4883 high-quality relocations. The distribution of relocated events shows several isolated clusters of seismicity at the trench, which are distributed nearly vertical, from the near-surface to 80 km depth. Feature with Vp/Vs ~ 1.73, which higher compared to value along the trench, coincides to one of the isolated clusters. Gaps are observed between bands of seismicity at the trench and beneath the forearc region. The seismicity is distributed surrounding or between the high anomalies of residual bathymetry which represent the structure of the subducting slab. Beneath the forearc, bands of seismicity are observed between 30 – 80 km depth and below 100 km depth. Their distribution reveals a steeper slab geometry relative to previously published slab models (Slab 1.0 and Slab 2.0). Several features with Vp/Vs < 1.70 and higher Vp and Vs than the surrounding area coincides with the bands of seismicity observed between 30 – 80 km depth. Shallow structure is also well defined by the earthquake relocations outlining three major faults (Cimandiri, Kencana-Rakutai faults, and an unnamed fault located east of Opak fault). The relocation results and velocity structure show that the distribution of seismicity along the subduction zone is segmented. This segmentation is likely related to the structure of the subducting plate.

To a first order, the Caribbean plate converges obliquely at ~2 cm/yr toward the North American plate. This transpression is partly accommodated across the island of Hispaniola by the partitioning of motion between a fold-and-thrust belt trending NW-SE, and two E-W left-lateral fault systems located 150 km apart. The southern fault, the Enriquillo-Plantain Garden Fault (EPGF), is morphologically well expressed in western Haiti but its precise geometry in eastern Haiti is debatable. There, Lake Azuei stretches over 20 km in a direction parallel to the fold-and-thrust belt while its southern shoreline strikes EW, parallel to the expected trend of the EPGF. Because of a high sedimentation rate, the history of transpressional deformation should be captured in the lake stratigraphy and, accordingly, we acquired 220 km of multichannel seismic reflection (MCS) profiles across its surface. The survey followed a grid pattern with a spacing of 1.2 km and achieved a penetration of up to 300 m beneath lakebed. Interpretation of the dataset documents two major structures. First, the western side of the lake is occupied by a broad NW-trending monoclinal fold. This fold is cross-cut by a few NW-striking vertical (strike-slip) faults. We propose that this monocline is the surface expression of a SW-dipping blind thrust fault. The progressive steepening of the seismic horizons with depth suggests that it has been continuously active during the deposition of at least 300 m of sediments. The other major structure consists of a ~2 km-wide deformation zone that borders the EW-trending southern shore. This deformation zone is faintly imaged below a shallow gas front. We tentatively propose that it corresponds to a set of fault-propagation folds that are developing ahead of an EW, S-dipping oblique-slip fault. Such a model has been proposed already from three other independent studies involving GPS monitoring, seismological monitoring, and detailed field mapping. It is also supported by CHIRP profiles acquired concurrently with our MCS data and that document folding of the topmost turbidites but a lack of evidence for any stratigraphic offset across faults. Furthermore, a set of en echelon folds in that area are trending EW, while WNW-ESE fold axes would be expected instead above an EW vertical strike-slip fault.

The increasing frequency and severity of flash droughts pose a threat to global food and water security and seasonal climate forecasts. We introduce a new tool for near-real-time global flash drought monitoring with SMAP leveraging the footprint-scale thresholds of soil hydrologic regimes (energy-limited wet phase, moisture limited transitional, and dry phase) and land-atmospheric coupling strength. We define two complementary indices based on SMAP soil moisture for measuring the severity and the rate of intensification of drought, namely, Soil Moisture Stress (SMS) and Relative Rate of Drydown (RRD), respectively. SMS and RRD are non-linearly combined to provide FDSI (Flash Drought Stress Index) ─ a composite indicator used for global flash drought monitoring. Several advantages of FDSI include non-reliance on long-term soil moisture records, sensitivity to changing land-surface heterogeneity, land-atmospheric interactions, and evolving meteorological anomalies. FDSI is extensively validated globally across multiple timescales (daily, weekly, and monthly) using a suite of vegetation and meteorological drought indices. We demonstrate the application of FDSI in the mechanistic evaluation of select recent flash droughts across the globe (Northern Great Plains in 2017, South Africa in 2015-2016, and Eastern Australia in 2019-2020), and the onset of the ongoing (since 2020) heatwave induced drought in the western U.S. Through this presentation, we introduce the viewers to the open-source web-based resources for accessing global FDSI estimates and related geospatial parameters.

Back Radiation to the Earth does not warm the Earth. Some say that the back radiation referred to above heats the Earth's surface. That can't happen. The Earth can't heat itself from its own radiation.

Basal melting of ice shelves is fundamental to Antarctic Ice Sheet mass loss, yet direct observations are sparse. We present the first melt record (2017 to 2021) from a phase-sensitive radar at Fimbulisen, East Antarctica, one of the fastest flowing ice shelves in Dronning Maud Land. The observed long-term mean ablation below the central part of the ice shelf was 1.0 ±0.4 m yr–1, marked by substantial sub-weekly variability ranging from 0.3 to 3.8 m yr–1. 36-h filtered fluctuations in basal melt exhibit a close alignment with ocean velocity, revealing shear-driven turbulent heat transfer as the predominant driver of melt variability at sub-weekly to monthly timescale. Seasonally, basal melt rates are highest in the austral summer, when ocean temperature is higher. Our observed in-situ melt rates show threefold lower amplitudes and a 3-month delay in seasonality compared to satellite-derived melt rates, however, the long-term multi-year mean is of similar magnitude (1.0 m yr–1 vs 0.8 m yr–1). Our detailed ice–ocean observations provide essential validation data for remote sensing and numerical models aiming to measure and project ice-shelf response to ocean forcing. In-situ measurements and continued monitoring are crucial for accurately assessing and modelling future basal melt rates, as well as understanding the complex dynamics driving ice-shelf stability and sea-level change.

Knowledge about the early life history of Antarctic toothfish (Dissostichus mawsoni) is still incomplete, particularly on the spatial and temporal extent of spawning and the subsequent transport of eggs and juveniles from the offshore spawning areas to the continental shelf. This study used a high-resolution hydrodynamic model to investigate the impact of ocean circulation and sea-ice drift on the dispersal of eggs and juvenile Antarctic toothfish. The virtual eggs were released on seamounts of the Pacific-Antarctic ridge in the northern Ross Sea and advected using hydrodynamical model data. Particles were seeded annually over a 14-year period (2002 to 2016) and tracked for three years after release. Spawning success was evaluated based on the number of juveniles that reached known coastal recruitment areas, in the eastern Ross and Amundsen Sea, within three years. Observations show that juveniles (50-100 cm size class) are abundant on the shelf and slope of the Ross and Amundsen Seas. Sensitivities to certain juvenile behaviours were explored and showed that spawning success was reduced by around 70% if juveniles drifted with sea-ice during the second winter season as this carried them into the open ocean away from the shelf region. Spawning success increased during the second winter season if juveniles were entrained in the Ross Gyre circulation or if they actively swam towards the shelf. These modelling results suggest that the ecological advantage of sea-ice association in the early life cycle of toothfish diminishes as they grow, promoting a behaviour change during their second winter.

Because remote sensing (RS) data are spatially and temporally explicit and available across the globe, they have the potential to be used for predicting runoff in ungauged or poorly gauged catchments, a challenging area of research in hydrology over the last several decades. There is potential to use remotely sensed data for calibrating hydrological models in regions with limited streamflow gauges. This study conducts a comprehensive investigation on how to incorporate gridded remotely sensed-evapotranspiration (AET) and water storage data for constraining hydrological model calibration in order to predict daily and monthly runoff in 30 catchments of Yalong River basin, China. To this end, seven RS data calibration schemes are explored, compared to traditional calibration against observed runoff and traditional regionalization using spatial proximity. Our results show that using bias-corrected remotely sensed AET (bias-corrected PML-AET data) for constraining model calibration performs much better than using the non bias-corrected remotely sensed AET data (non bias-corrected AET obtained from PML model estimate). Using the bias-corrected PML-AET data in a gridded way is much better than that in a lumped way, and outperforms the traditional regionalization approach especially at upstream and large catchments. Combining the bias-corrected PML-AET and GRACE water storage data performs similarly to using the bias-corrected PML-AET data only. This study demonstrates that and there is great potential to use RS-AET based data for calibrating hydrological models in order to predict runoff in data sparse regions with complex terrain conditions.

Recent years have witnessed devastating weather extremes, so it is no surprise that people have started wondering, “what’s up with the weather?” The potential role of climate change in making these extremes worse has gained traction not only in the scientific community but in public discourse a well. While scientists have made considerable progress on statistical “climate attribution”—a way of assessing the probability that climate change is influencing the character of some extreme weather events—public understanding has not kept pace. However, members of society do not need to know everything about climate and its related changes to make decisions. Rather, building climate literacy across society is paramount to better inform those decisions. There are many facets of climate literacy and many ways to help society become comfortable with the concepts. While riddled with challenges, one way of explaining the statistical methods around climate attribution is through carefully designed spinner boards. This is just one demonstration of how to explain a difficult subject, and if properly developed and used, this method holds the potential to significantly improve climate literacy.

We present a new approach that allows for the inversion of quantities derived from the observed data using non-diagonal data covariance matrices. For example, we can invert approximations of apparent resistivity and phase instead of magnetotelluric impedance using this methodology. Compared to the direct inversion of these derived quantities, the proposed methodology has two advantages: i) If an inversion algorithm allows for the specification of a full data covariance matrix, users can invert for arbitrary derived quantities by specifying the appropriate covariance matrix instead of having to rely on the inversion code to have implemented this feature. ii) It is fully compatible with the assumptions of least-squares optimization and thus avoids potential issues with bias when inverting quantities that are non-linear functions of the original data, We discuss the theory of this approach and show an example using magnetotelluric data. However, the same method can be applied to other types of geophysical data, for example gravity gradient measurements.

We present a new open-source tool for magnetospheric computations, that is modelling of cosmic ray propagation in the geomagnetosphere, named the “Oulu - Open-source geomagneToSphere prOpagation tool” (OTSO). A tool of this nature is required in order to interpret experiments and study phenomena within the cosmic ray research field. Within this work OTSO is applied to the investigation several ground level enhancement events. Here, we demonstrated several applications of OTSO, namely computation of asymptotic directions of selected cosmic ray stations, effective rigidity cut-off across the globe at various conditions within the design, general properties, including the magnetospheric models employed. A comparison and validation of OTSO with older widely used tools such as MAGNETOCOSMICS was performed and good agreement was achieved. An application of OTSO for providing the necessary background for analysis of two notable ground level enhancements is demonstrated and the their spectral and angular characteristics are presented.

The food-energy-water (FEW) nexus has emerged as an alternative to improve the management of the resources used in the food, energy, and water systems. However, there are limited case studies in the Latin American and Caribbean region where a FEW nexus methodology has been implemented. This region will greatly benefit from a FEW nexus approach since more than half of the electricity comes from hydropower, and even though the region has excess in water resources, these resources are not equally distributed and they are poor managed. In this study, an urban FEW nexus framework was used in the Otun River Watershed (ORW) to evaluate the changes in food, energy, and water demand for four scenarios (base scenario, year 2017; scenario 1, year 2035-population growth; scenario 2, year 2035-population growth and reduction in locally produced food; scenario 3, year 2035-population growth and increase in electricity generated locally). Additionally, regional climate models (RCMs) were used to estimate the water availability in the ORW from 2030-2039. The results show that water demand could increase by 16% and energy demand will increase roughly 15% for scenario 2, while water demand in scenario 3 will likely remain unchanged in relation to the current conditions (base scenario). As the Latin America and Caribbean region is the most urbanized region in the world, the modeling tool developed as part of this study may be implemented in other urban watersheds in the Andean Region.

Top-down estimates of CO2 fluxes are typically constrained by either surface-based or space-based CO2 observations. Both of these measurement types have spatial and temporal gaps in observational coverage that can lead to biases in inferred fluxes. Assimilating both surface-based and space-based measurements concurrently in a flux inversion framework improves observational coverage and reduces sampling biases. This study examines the consistency of flux constraints provided by these different observations and the potential to combine them by performing a series of six-year (2010–2015) CO2 flux inversions. Flux inversions are performed assimilating surface-based measurements from the in situ and flask network, measurements from the Total Carbon Column Observing Network (TCCON), and space-based measurements from the Greenhouse Gases Observing Satellite (GOSAT), or all three datasets combined. Combining the datasets results in more precise flux estimates for sub-continental regions relative to any of the datasets alone. Combining the datasets also improves the accuracy of the posterior fluxes, based on reduced root-mean-square differences between posterior-flux-simulated CO2 and aircraft-based CO2 over midlatitude regions (0.35–0.50~ppm) in comparison to GOSAT (0.39–0.57~ppm), TCCON (0.52–0.63~ppm), or in situ and flask measurements (0.45–0.53~ppm) alone. These results suggest that surface-based and GOSAT measurements give complementary constraints on CO2 fluxes in the northern extratropics and can be combined in flux inversions to improve observational coverage. This stands in contrast with many earlier attempts to combine these datasets and suggests that improvements in the NASA Atmospheric CO2 Observations from Space (ACOS) retrieval algorithm have significantly improved the consistency of space-based and surface-based flux constraints.