bluuebunny/crossref_metadata_2025 huggingface dataset:
Deep Learning Driven DAS Strain Conversion to Geophone Ground Motion
Authors: Al-Qadasi Basem , Bin Waheed Umair
Published: March 2024

Distributed Acoustic Sensing (DAS) has become a revolutionary observational technology for different geophysical applications. DAS, known for its high spatial resolution, environmental resilience, and ease of deployment, which make it a potential replacement to the traditional physical sensors that have been used for decades in seismology. The primary distinction between DAS and conventional seismic sensors lies in the fact that DAS inherently captures strain (or strain rate), in contrast to seismic instruments which record translational ground motions. However, the problem of strain directional sensitivity poses challenges for its direct use in standard seismic analysis. Therefore, several physics-based methods have been proposed to convert DAS strain to ground motion response (displacement, velocity, or acceleration). Efficient conversion of strain to ground motion using physics-based methods relies on accurate estimation of phase velocity along the DAS cable which is unavailable in most cases. To overcome this problem, we introduce a novel deep learning (DL) approach to convert high-resolution Distributed Acoustic Sensing (DAS) strain measurements into ground motion (GM).  The DL model employs a Bidirectional Long Short-Term Memory (BiLSTM) network. The model is trained and evaluated utilizing data from the PoroTomo project at Brady Hot Springs Geothermal Natural Laboratory. This dataset includes earthquake waveforms recorded by collocated DAS channels and geophones. The model’s performance is evaluated using the Root Mean Squared Error (RMSE) metric. It demonstrated an average RMSE of 0.41 for training and 0.95 for testing, indicating the model's efficacy in transforming DAS strain to particle velocity. The comparison results of predicted and original geophone waveforms further validated the model's accuracy within the relevant frequency range. This study marks a significant advancement in adapting high-resolution DAS strain data for use with conventional seismic data analysis techniques, thereby expanding the capabilities of seismic monitoring and interpretation.
Occurrence and fate of perfluoroalkyl and polyfluoroalkyl substances (PFASs) in an urban aquifer located at the Besòs River Delta (Spain)
Authors: Sáez Camacho Carmen , Bautista Arianna , Nikolenko Olha , Scheiber Laura , Farré Marinella , Jurado Anna , Pujades Estanislao
Published: March 2024

Due to the increasing demand of water, urban aquifers are an alternative source of water supply. However, they are at risk of contamination from persistent and mobile organic compounds (PMOCs), especially per- and polyfluoroalkyl substances (PFASs), which are artificial organic substances widely used across various industrial sectors. PFASs are considered toxic, mobile and persistent, and have therefore gained significant attention in environmental chemistry. Moreover, PFASs precursors transform into more recalcitrant and mobile products under natural conditions. Therefore, it is needed to investigate the fate of PFASs when they reach aquifers to use groundwater safely. However, there is limited information about the processes which affect their behaviour in groundwater, especially at the field-scale. In this context, the aim of this investigation is to assess and identify processes that control the evolution of PFASs in an urban aquifer in Barcelona, where groundwater behaves analogously to a river bank filtration system. A part from PFASs, 4 PMOCs were also analysed. During a summer campaign, 21 groundwater and 6 river samples were collected revealing the presence of 17 PFASs products, 3 novel PFASs and 4 PMOCs non-PFASs. PFASs products were found to be ubiquitous, with the highest concentrations found in PFBS, TFA and TFSA. Non-PFASs and novel PFASs, with the exception of Sulfanilic acid, were found to be present in very low concentrations. It was observed that the redox conditions influence the behaviour of a number of PFASs controlling their attenuation capacity or recalcitrant behaviour. Most substances showed accumulation, possibly explained by sorption/desorption processes or by transformation processes, highlighting the challenges associated with PFASs remediation. In addition, the PFAS TFSA and two of the longest chain PFASs detected presented removals at different intensities. Our results will have tremendous implications for establishing the evolution of PFASs along the groundwater flow and might be extended to similar research areas such as Manage Aquifer Recharge techniques.
Seismic imaging of crustal fault systems
Authors: Krawczyk CharLotte
Published: March 2024

The construction of geodynamic and reservoir models requires - as many other applications - the knowledge of fault signatures and fracture systems.  In general, structural images of the subsurface rely on sampling and experiment design, wavefield components retrieved, as well as coherence and focusing potential of the data recorded in different geological settings.  Nonetheless, direct geophysical images of especially sub-/vertical or inactive faults are still hampered by fracture complexity and associated diffuse wavefields.  Furthermore, back-tracing weak signals to their originating location remains one of the challenges for high-resolution imaging.  While petrophysical and mechanical rock properties characterize the hosting material as such, they can provide at the same time assistance in fault or horizon tracking, respectively, and may allow pattern identification, for instance by machine learning tools.In the overview presented, we will discuss different examples from recent active and passive seismic surveys covering both sedimentary and hardrock environments using either dense or sparse seismic and fibre-optic arrays.  These experiments are adapted to investigation depths between some km and only few 10s of metres scale, encompassing geodynamic, geothermal, hazard and critical zone investigations.  Thereby, the wide applicability of seismic methods for imaging and characterizing distinct horizons, transitional zones, and fault systems is emphasized.
Fine silicate dust from Chicxulub crater excavation shuts down photosynthesis for up to 2 years after the K-Pg impact. 
Authors: Claeys Philippe , Senel Cem Berk , Kaskes Pim , Temel Orkun , Vellekoop Johan , Goderis Steven , Prins Maarten A. , Karatekin Ozgur
Published: March 2024

Formation of the ± 200 km in size Chicxulub crater is widely regarded as the leading cause of the Cretaceous-Paleogene (K-Pg) boundary mass extinction, 66 million years ago. Nevertheless, the precise climatic outcome of the various debris ejected into the atmosphere following the crater excavation, thus the killing mechanisms remain not definitely understood. Present paleoclimate scenarios confer a substantial role in sulfur components released by the vaporization of evaporite layers present in the upper part of the target rock. Sedimentological constraints acquired from an expanded terrestrial K-Pg boundary deposit in North Dakota and measured volumetric size distribution of silicate dust indicate the release into the atmosphere of fine silicate dust (~0.8-8 μm). The new general circulation model simulations of the injection of such a plume of micrometer-sized silicate dust (2x1018g) suggest a long atmospheric residence time (±15 years) with a global-average surface temperature falling by as much as 15ºC. Simulated effects on the post-impact active solar radiation support a dust-induced photosynthetic shut-down for approximately 2 years. Contrary to previous work, these new paleoclimate simulations, relying on robust sedimentological field data at the K-Pg boundary revealed that the impact-generated silicate dust plume plays a pivotal role in driving the K-Pg climate and biotic crisis. The new scenarios showcase that the global darkness and prolonged loss in the planet's photosynthetic activity happen solely in the silicate dust scenario, up to nearly 1.7 years after impact; a sufficiently long timescale to pose severe challenges for terrestrial and marine habitats. Biotic groups not adapted to survive the dark, cold, and food-deprived conditions for almost two years, experienced massive extinctions. In addition, this emission scenario shows that the photosynthetic recovery to the pre-impact levels first occurred in the austral summer season, ~1.7 years after impact. This would imply a potential earlier recovery of primary productivity in the Southern Hemisphere. These new findings highlight that the photosynthetic shut-down induced by the large volume of silicate dust, together with additional effects of sulfur and soot likely led to the collapse of primary productivity in land and ocean realms, steering the global mass extinction at the K-Pg boundary.
Understanding glacier processes to decode the drivers of glacier change
Authors: Flowers Gwenn
Published: March 2024

Detection, attribution and projection of glacier and ice-sheet change characterize much of our community’s work, motivated in part by the associated impacts ranging from local hazards to regional water supply to global sea-level rise. Toward improved attribution of glacier change on local to regional scales, I profile work aimed at discerning the internal versus external drivers of glacier behaviour through process-oriented studies. Using examples from northern Canada, combining observational and numerical approaches improves our understanding of fundamental processes that define the boundary conditions at the ice interface with bedrock, water and atmosphere. These studies have allowed us to revisit questions related to glacier surging, hydrology and ice-dammed lakes and the co-evolution of glacier geometry and thermal structure, with occasionally surprising and counter-intuitive results.While the internal dynamics of glacier systems have the potential to confound the climate signal on societally relevant timescales, the direct effects of climate via surface mass balance remain as important as ever. Improved observational platforms, advances in modelling and the growing abundance and availability of remotely sensed data have amplified our capacity to study these systems, and more generously than ever reveal information archived by glacier processes. Using these tools, we are now beginning to disentangle the contributions of the geologic substrate, environmental setting, internal ice dynamics and climate forcing to observed glacier change in globally significant ice-rich parts of the world.
A two-phased Heinrich Stadial 11 as revealed by alkenone-based temperature record from the western tropical North Atlantic 
Authors: Zhuravleva Anastasia , Fahl Kirsten , Bauch Henning A.
Published: March 2024

Paleo-data and models show that reductions in the strength of the Atlantic meridional overturning circulation (AMOC) lead to significant subsurface warming in the western tropical North Atlantic. The thermal response at the sea surface is less constrained due to the competing nature of the atmospheric and oceanic processes that produce opposite signs of temperature change. Here, we used alkenone unsaturation in sediments to reconstruct sea surface temperature (SST) evolution in the southeastern Caribbean (core MD99-2198, 1330 m water depth) during the last glacial-interglacial cycle, including Heinrich Stadial 11, which was a period of intense AMOC weakening. Our data show a 1 °C SST warming associated with the onset of Heinrich Stadial 11, and a 1 °C cooling during the late Heinrich, followed by a gradual 1 °C warming during the early last interglacial. Although stadial events are generally associated with wind-induced surface cooling in the tropical North Atlantic, the positive Caribbean SST anomaly during Heinrich Stadial 11 is consistent with previous findings. It likely originates from the upwelling of subsurface water that warmed in response to the initial AMOC weakening. Reduction in the Caribbean SST during the late Heinrich, associated with a particularly weak AMOC strength as suggested by our benthic d13C values, can indicate that the subsurface warming has diminished in the tropical North Atlantic possibly due to a general cooling in the source region (i.e., the subtropical gyre). A two-phased Heinrich is supported by the planktic foraminifera assemblage data, indicating that cooling occurred in the late Heinrich. In addition, this late phase is characterized by coarser sediments, which can be due to a strongly reduced outflow of the Orinoco and a particularly southern position of the intertropical convergence zone. For the last interglacial, our alkenone-derived SST record suggests stable conditions. However, the obtained interglacial values are characterized by very high alkenone unsaturation indexes that can incorporate large measurement and calibration errors due to the lack of Caribbean sediment traps and core-top data. These results, therefore, emphasize the need to better quantify the effectiveness of alkenones in reconstructing interglacial SST history in the Caribbean.
Irrigation-induced impacts on near-surface climate under future scenarios
Authors: Yao Yi , Satoh Yusuke , van Maanen Nicole , Taranu Sabin , Lampe Seppe , Wada Yoshihide , Lawrence David , Sacks Bill , Weider Will , Jägermeyr Jonas , Schleussner Carl-Friedrich , Thiery Wim
Published: March 2024

Irrigation plays an essential role in the Earth system by changing water, energy, and carbon fluxes, and then affecting the climate. Many previous studies have been conducted to explore its impacts on near-surface climate, highlighting its cooling effects on air temperature, especially during hot extremes. However, most studies do the exploration during the historical period and only focus on temperature. Projected greenhouse gas emissions and land use datasets have made it possible to extend the investigation under future scenarios, but there are no datasets about predicted irrigation techniques shares information. To address this issue, we create a dataset containing spatial distribution of drip, sprinkler, and flood irrigation techniques, based on a simple assumption that richer and drier countries will invest more in irrigation system upgrades. Then, the Community Earth System Model version 2 (CESM2) is developed to be able to represent different irrigation techniques for one crop type in one gridcell. Finally, with the newly created dataset and modified CESM2, we detect irrigation's impacts on heat and moist-heat stress under SSP1-2.6 and SSP3-7.0. Simulation outputs indicate that irrigation will experience various changes among regions and scenarios. In irrigation hot spots, irrigation will continue to reduce the probability of high-temperature extremes under both scenarios but cannot reverse the warming signal caused by other forcings. Moreover, irrigation's impacts on apparent temperature are very small, and even increase the hours exposed to wet bulb temperature extremes in some regions. This study reveals that irrigation's cooling impacts will persist in the future, but will not be an effective solution to the global warming issue. As for moist-heat stress, irrigation's effects are much more complicated due to its enhancing impacts on air humidity.
Exploring the connectivity between glacier melt, groundwater and climate change in the Cordillera Blanca, Peru
Authors: McNamara Gavin , Aubry-Wake Caroline , Somers Lauren , McKenzie Jeffrey , Pomeroy John W. , Hellström Robert
Published: March 2024

Glacier melt is known to provide an important source of water to streamflow in glacierized tropical regions, especially during the dry season. Groundwater also contributes a significant amount to streamflow. However, the linkage between the two is often unclear: How much groundwater originates from glacier melt? More broadly, how will groundwater and surface water contributions to streamflow change as glaciers retreat and climate changes? We developed a glacio-hydrological model in the Cold Region Hydrological Modelling platform to explore the complex interactions among the cryosphere, surface water, and groundwater in Peru's Cordillera Blanca, specifically in the Quilcayhuanca valley. The model uses meteorological observations from the valley and is parameterized using numerous data sources and process-based studies in the valley. Our findings reveal that during the dry season, 24 % of streamflow is routed through the groundwater reservoir, increasing to 40 % during the lowest flows. In a simulation without glaciers, streamflow discharge decreases by 34 % during the wet season and by 54 % during the dry season, with the groundwater contribution to streamflow decreasing by 55 % and 52 % for the wet and dry seasons, respectively. This simplified approach suggests that approximately half of the annual groundwater contribution to the stream originates from glacier wastage. We conducted sensitivity scenarios to evaluate the basin's resilience to the range of possible changes in precipitation, temperature and glacier cover expected by 2100. In a nearly deglaciated basin, the sensitivity to the range of tested temperature (+0 to 5 °C) produced a streamflow ranging from -60 to -49 % of current conditions in the dry season, and the range of tested precipitation (-20 % to +20 %) produced a streamflow ranging between -78 to -35 % of current conditions, indicating a larger sensitivity to potential changes in precipitation. Expected ratio changes were smaller during the wet season but followed a similar pattern. In the most likely scenarios by 2100, under RCP 8.5, wet season streamflow is predicted to decrease by 17 to 27 %, and dry season streamflow by 28 to 52 %. Despite a substantial decline in snow and ice contributions under climate change and deglaciation, the groundwater zone's contribution to streamflow shows relatively minor changes, demonstrating the low sensitivity of the groundwater system to climate shifts and glacier variations.
Paleoclimate Evaluation, Paleodiversity and Paleobiogeography of the Middle-Upper Eocene Foraminifera from north-west Fayum Area, Egypt.
Authors: Sayed Mostafa Mohamed , Heinz Petra , Abd El-Gaied Ibrahim Mohamed , Wagreich Michael
Published: March 2024

This study deals with the investigation of the benthic foraminiferal assemblage from the Middle–Upper Eocene succession that is exposed in the northwest of Fayoum area, Egypt. The studied section is lithostratigraphically described and subdivided into three rock units named from base to top as follow: The Gehannam Formation (Bartonian), the Birket Qarun and the Qasr El-Sagha formations (Priabonian). The examination of fifty rock samples yielded 104 benthic foraminifera species which belong to 31 genera, 23 families, 13 superfamilies and 4 suborders.  The recorded planktonic foraminifera showed rare and scattered occurrences through the studied succession, therefore it does not allow a precise biostratigraphic correlation. The Eocene age of the studied section is assigned based on the co-occurrence of the index small sized planktonic and benthic foraminiferal species. The recorded benthic foraminifers were subjected to cluster analysis to gain insights into the relation between the distribution of the benthicforaminiferal communities and the prevailing paleoenvironmnetal conditions. The observed low Total Organic Carbon (TOC) values of the studied samples could be attributed to either significant high sediment influx or the dominance of high oxygenated conditions. X-ray diffraction (XRD) results show that kaolinite is the dominant clay minerals in the analyzed samples, indicating high chemical weathering during warm and humid greenhouse climatic conditions. The identified species displayed significant resemblances to adjacent regions in the southern Tethys, like Libya, indicating potential migration through the trans-Sahara seaway. However, there were only slight similarities with species found in the northwestern Tethys and the North Atlantic regions. This can be attributed to the benthic nature of these species, limiting their ability to migrate over long distances. Furthermore, it is associated with cooler, latitudinal zoned climatic conditions prevailing along the northwestern Tethys, which did not align with their specific biological requirements. 
Gondwanan Flood Basalts Linked Seismically to Plume-Induced Lithosphere Instability
Authors: Shi Ya-Nan , Morgan Jason
Published: March 2024

Delamination of continental lithospheric mantle is now well-recorded beneath several continents. However, the fate of delaminated continental lithosphere has been rarely noted, unlike subducted slabs that are reasonably well imaged in the upper and mid mantle. Beneath former Gondwana, recent seismic tomographic models indicate the presence of at least 5  horizontal fast-wavespeed anomalies at ~600 km depths that do not appear to be related to slab subduction, including fast structures in locations consistent with delamination associated with the Paraná Flood Basalt event at ~134 Ma and the Deccan Traps event at ~66 Ma. These fast-wavespeed anomalies often lie above broad slow seismic wavespeed trunks at 500-700 km depths beneath former Gondwana, with the slow wavespeed anomalies branching around them. Numerical experiments indicate that delaminated lithosphere tends to stagnate in the transition zone above a mantle plume where it shapes subsequent plume upwelling. For hot plumes, the melt volume generated during plume-influenced delamination can easily reach ~2-4×106 km3, consistent with the basalt eruption volume at the Deccan Traps. This seismic and numerical evidence suggests that observed high wavespeed mid-mantle anomalies beneath the locations of former flood basalts are delaminated fragments of former continental lithosphere, and that lithospheric delamination events in the presence of subcontinental plumes induced several of the continental flood basalts associated with the multiple breakup stages of Gondwanaland. Continued upwelling in these plumes can also have entrained subcontinental lithosphere in the mid-mantle to bring its distinctive geochemical signal to the modern mid-ocean spreading centers that surround southern and western Africa.
Antarctic Bottom Water on Global Ocean General Circulation Model and Reanalysis outputs
Authors: M. C. Santos Daniel , T. Sato Olga
Published: March 2024

The Antarctic Bottom Water (AABW) is the deepest, densest, and coldest water in the global ocean. Its distinctive properties and formation primarily result from the mixing between the colder and denser Antarctic Shelf Water and the lighter, warmer, and saltier Circumpolar Deep Water along the Antarctic slope. Past investigations have already demonstrated shifts in AABW characteristics over recent decades, with assessments of temperature, salinity, dissolved oxygen, and layer thickness trends conducted in various regions. These studies heavily relied on in situ data for AABW evaluation. However, measuring abyssal depths is a challenging task. Until now, the predominant data sources have been moorings and decadal hydrographic sections, yet the inherent limitations of in situ data from abyssal layers arise due to low sampling rates and restricted geographical coverage.To address these temporal and spatial gaps, utilizing model and reanalysis outputs emerges as a logical solution. This study aims to investigate trends in AABW properties in high and mid latitudes at different basins worldwide using such outputs. In the initial phase of assessing AABW's properties variability, we evaluate the capability of two reanalyses and a model in accurately representing AABW, they are: 1. Estimating the Circulation and Climate of the Ocean (ECCO); 2. Copernicus Global Oceanic and Sea Ice GLORYS; 3. JAMSTEC OFES Ocean General Circulation Model for the Earth Simulator (OFES). To validate these outputs, we employ climatology from WOA18 and in situ data from the SAMBAR project.The results indicate that ECCO has a problem with bathymetric representation, with larger values of AABW thickness (h) found in regions with greater depths, particularly in the southern portion of the Argentine Basin, in comparison to the reference WOA18. GLORYS, on the other hand, appears to misrepresent h by consistently underestimating it across all studied domains, from high to mid latitudes. On the contrary, OFES tends to overestimate h in the high latitudes but underestimate it in the mid latitudes.
Soil fauna presence in post-mining area after afforestation with diverse tree species
Authors: Ogar Wiktoria , Schmelz Rüdiger M. , Woś Bartłomiej , Wanic Tomasz , Pietrzykowski Marcin , Józefowska Agnieszka
Published: March 2024

Soils around the world are facing increasing degradation due to human activities such as mining. This degradation adversely affects soil functioning and, consequently, the ecosystem services it provides. Therefore, our research concerns various strategies for restoring forest ecosystems at such sites. Soil fauna can play a key role in restoring degraded soils, positively influencing their properties, especially in the case of newly formed soils. Providing an influx of organic matter, such as through afforestation, can promote the growth of microorganisms and subsequently facilitate the emergence of soil fauna and the process of soil formation.Our main research question is how different tree species and soil disturbances, in this case especially mining, affect enchytraeid and earthworm communities and how soil fauna contribute to the soil-forming process in post-mining soil. We selected sandy soil in sandpit excavations afforested with various tree species, including Scots pine (Pinus sylvestris L.), European larch (Larix decidua Mill.), Silver birch (Betula pendula Roth) and European oak (Quercus robur). Soil profiles were described and samples were taken for basic soil analysis, including pH, soil organic carbon and nitrogen content, and soil porosity. In addition, earthworms and enchytraeids were collected from all plots to assess the density and species diversity of the soil fauna.Based on the WRB classification, the studied soils were classified as Arenosols. The studied soils generally showed acidic pH, subangular structure in the upper layers and slightly acidic pH with a lack of structure in the subsoil. Slight differences were observed in the thickness of the humus layer between the soil profiles. Areas undergoing reclamation after sand mining were characterized by low enchytraeid densities. The Shannon index reached the highest value for the birch site and was 0.64 and the lowest for the pine site and was 0.08. In turn, the highest density of enchytraeid occurred at the oak site and was 34574 ind. m-2 and the lowest at the larch site and was 10123 ind. m-2. Soils under deciduous species show higher density and biomass of earthworms compared to soils under coniferous species. The highest density of earthworms was noted at the birch site and was 25 ind. m-2 and the lowest at the larch site and was 0 ind. m-2. It is worth noting that the birch site showed the highest diversity of enchytraeid species and highest abundance of an earthworm species. The density of the studied soil fauna was not high, but their presence and diversity may indicate a positive trajectory of changes occurring in these soils. This research was funded by The National Science Centre, Poland, grant No. 2021/42/E/ST10/00248. The analyses were performed in the Laboratory of Forest Environment Geochemistry and Reclaimed Areas, University of Agriculture in Krakow.Key words: earthworm, enchytraeid, sand mine, sandy soil
Multi-decadal evolution of Crary Ice Rise region, West Antarctica, amidst modern ice stream deceleration
Authors: Verboncoeur Hannah , Siegfried Matthew , Winberry J. Paul , Holschuh Nicholas , Byrne Duncan , Sauthoff Wilson , Sutterley Tyler , Medley Brooke
Published: March 2024

The ongoing deceleration of Whillans Ice Stream, West Antarctica, provides an opportunity to investigate the role of grounded ice flux in downstream pinning point evolution on decadal time scales. Here, we construct and analyze a 20-year, multi-mission satellite altimetry record of dynamic ice surface-elevation change (dh/dt) in the grounded region between lower Whillans Ice Stream and Crary Ice Rise, a major Ross Ice Shelf pinning point. We developed a new method for generating multi-mission time series that reduces spatial bias and implemented this method with altimetry data from the Ice, Cloud, and land Elevation Satellite (ICESat; 2003–09), CryoSat-2 (2010–present), and ICESat-2 (2018–present) altimetry missions. We then used the 20-year dh/dt time series to identify persistent patterns of surface elevation change and to evaluate regional mass balance. Our results suggest that changes in ice flux associated with Whillans Ice Stream stagnation drive non-linear mass change responses isolated to the Crary Ice Rise region, producing persistent, spatially heterogeneous thickness changes. The resulting mass redistribution modifies the grounding zone and mass balance of the Crary Ice Rise region, in turn adjusting the buttressing regime of the southern Ross Ice Shelf embayment.
First constraints on the timing of structural evolution of the north Sulaiman Fold-thrust belt, Pakistan 
Authors: Ali Nowrad , Sobel Edward R. , Ghani Humaad , Bernhardt Anne
Published: March 2024

The Sulaiman and Kirthar fold-and-thrust belts constitute the western boundary of the India-Asia collision zone. The Sulaiman fold-thrust belt is composed of a passive margin sedimentary sequence of Mesozoic to Cenozoic platform carbonates and clastic sedimentary rocks overlain by younger Himalayan foreland basin molasse sediments. This study uses newly acquired zircon (U‐Th)/He (ZHe) data and surface geology observations to document the structural evolution of the north Sulaiman fold-thrust belt. The hinterland zone includes the Zhob Valley Suture thrust, emplaced ophiolites, and folded Mesozoic strata, while the foreland is characterized by folded Eocene to Pliocene strata and hinterland-verging back thrusts. The initial deformation of the North Sulaiman Fold-thrust belt was driven by an east-west compressional event, giving rise to structures oriented in a north-south direction. The formation of fault propagation folds such as the Drazinda Syncline and Domanda Anticline in the foreland region resulted from east-vergent deformational events. Following this eastward deformation, the west-verging East Domanda Fault was activated, forming a roof thrust within the tectonic wedge beneath the Domanda Anticline.ZHe dates were obtained from Jurassic to Pliocene sandstone samples collected along the Drazinda-Zhob transect, crossing the Sulaiman Fold-thrust belt. ZHe ages from the Middle Jurassic (Chiltan Formation) and late Jurassic to early Cretaceous (Sembar Formation) samples are completely reset. ZHe ages from the late Cretaceous (Mughal Kot and Pab formations) to early Paleocene (Ranikot Formation) samples are partially reset to unreset; Eocene to Pliocene sample ages are unreset. ZHe ages for the Chiltan Formation range from 3.9-16.2 Ma with an average of 7.6 Ma. The ZHe ages for the Sembar Formation range from 5.5-41.4 Ma with an average of 15.2 Ma. The fully to partially reset ZHe ages for the Mughal Kot Formation range from 4.5 to 64.2 Ma with an average of 31.6 Ma. The ZHe ages of the Pab Formation samples range in age from 25.1-58.6 with an average of 44.9 Ma. A single partially reset ZHe age from the Ranikot Formation is 38.5 Ma. Thick and rapid sedimentation in the Late Cretaceous, Early Eocene and Miocene-Pliocene in the region resulted in sufficient burial of the Chiltan and Sembar formations to reset the ZHe system. Most of the reset ages from the Chiltan and Sembar formations range between 3.9-7.5 Ma, indicating rapid late Miocene to Early Pliocene uplift of the north Sulaiman Fold-thrust belt. This uplift is associated with development of the Sulaiman anticline and the associated Dhana Sar backthrust. Located along the western boundary of the Indian Plate, this area exhibits transpressional tectonics. The dominant east-west compression component coupled with left-lateral wrenching plays a key role in this rapid and young uplift in the north Sulaiman Fold-thrust belt.
Perspectives on limitations and mechanisms for atmospheric initiation of onset of the summer melt season over sea ice
Authors: Cox Christopher , Solomon Amy , Persson Ola , Shupe Matthew , Gallagher Michael , Walden Von , Town Michael , Perovich Donald , Webster Sarah , Anderson Jacob
Published: March 2024

Onset of surface melt over sea ice is a factor in the duration of the melt season. Onset is often triggered by advection of warm, moist air from lower latitudes. This is especially characteristic of early dates of onset, but such events have also been hypothesized to precondition the ice for an earlier onset even when they don’t act as the trigger. The importance of atmospheric advection to the melt season is well-recognized by the community. Less attention has been given to the potential limitations of these events and to what alternate mechanisms may also be important for initiation, which is the subject of this presentation. We discuss two case studies.In the first case, atmospheric advection from the North Atlantic in late May 2020 caused onset to occur over a wide area of the sea ice north of Greenland, including the floe being measured by the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition. Approximately 6 weeks prior, in April, an anomalously warm advection event also impacted the MOSAiC floe and was responsible for ~40% of the total warming the ice underwent that spring. Using a diffusion model for the ice forced by surface temperatures that both include (observationally) and exclude (synthetically) the April event, we show that its influence relative to its absence was reduced by ~80% within 10 days. The result is explained by a negative feedback that suppresses conduction within the ice when warming events occur. Consequently, despite the apparent influential nature of the April event suggested by the observations, the ice temperatures would likely have been similar several weeks before onset if the April event had not occurred. This implies there are limitations to such events in preconditioning the sea ice for early onset.Our second case examines data collected from a buoy in the Beaufort Sea during a regional onset event observed in June 2022. In this case, the air that caused melt at the buoy came from the north during a period of generally zonal flow of the polar jet (and lack of poleward moisture transport). Analysis of back trajectories indicates that the air had a residence time in the Arctic of 7-10 days prior to causing melt. The air began at mid-tropospheric levels near the pole then circulated around persistent, large-scale high pressure over the East Siberian Sea, descending along its track. Reanalysis data suggests the adiabatic contribution to the subsidence was sufficient to warm the air to the freezing point when it reached the surface, moving southward across the Beaufort Sea. This case indicates that subsidence is a mechanism internal to the Arctic that is capable of causing melt onset, though its climatological significance remains an open question.
Ripple patterns on Martian barchan dunes in the north: indicators of the flow regime.
Authors: Delobel Lucie , Baas Andreas , Moffat David
Published: March 2024

Aeolian sand transport occurs across the surface of Mars with the north polar region being one of its most active regions, however our understanding of sand transport conditions on the red planet is limited. Sand ripples reflect local flow regimes and are present on both Earth and Mars; but Martian ripples greatly vary in shape and size. Large ripples on Mars have meter-scale wavelengths but seemingly no coarse grains at their crests. Investigating the dynamics of large ripple patterns across Mars would improve our knowledge of local wind regimes and sand transport conditions.In this study, we have selected 40 HiRISE sites with a 25 cm/pixel resolution in the north polar region and cropped out hundreds of barchan dunes overlain by large ripples. The barchan images are filtered to remove the illumination effect, and the surrounding bedrock are masked. From a visual analysis of 20+ dunes, we have identified 3 ripple pattern types, straight, sinuous, and complex, which all reflect different flow regimes. Then, we have applied and compared two methods to automatically map these 3 ripple pattern classes using labels.Our first approach is a deep-learning algorithm based on the U-Net architecture which has been trained to recognise the ripple patterns from the labels and identify them on new data. Our second approach is computing a semi-variogram, using the labels as reference, and extracting the ripple wavelength, direction, and sinuosity. The spatial distribution of these later metrics over the dunes are used to infer the local wind regime around the north polar region of Mars. By doing so, we hope to enhance our understanding of sand transport conditions on the red planet.
An iterative algorithm for determining the temporal characteristics of solar X-ray flares for the automated formation of a data set in machine learning systems
Authors: Bilokon Oleksandr , Dudnik Oleksiy , Chechotkin Dmytro , Denkov Ivan
Published: March 2024

Modern astronomical instruments and devices in space provide scientists with a wealth of scientific and technical information. Scientists and developers are confronted with the question of how to gather, process, and store data that defines a particular phenomenon while developing artificial intelligence systems. An extensive array of data processing techniques is also employed in X-ray astronomy; however, the efficacy of these techniques is not universally reliable, which has consequential implications for the overall functionality of artificial intelligence systems and the likelihood of accurate classification. Automation and manual processes constitute the two broad categories into which these methods can be categorized. Each of these categories possesses distinct merits and demerits. Simplyified metric selection and precise definition are factors that contribute to such errors. This study examines the process of determining temporal metrics for the automated creation of a data set using the light curves of solar X-ray flares. The acquired data is designed for eventual utilization in machine learning systems. In order to determine the temporal characteristics of a solar X-ray flare, the flare's initiation, maximum, and termination points are postulated. The provided quantity of data points is adequate for ascertaining the X-ray burst's total duration, rise time, and decay time. Using an iterative algorithm, the authors suggest making it possible to automatically figure out the metrics related to the start, peak, and end of an X-ray flare. Researchers are testing the iterative algorithm on fake data made by the damped oscillations function, on fake periodograms that make the light curve more accurate, and on real data from solar X-ray bursts. This approach enables the automated extraction of temporal attributes of a solar X-ray burst for subsequent storage and aggregation as a database. It also facilitates further processing and utilization in the training of artificial intelligence systems.This work is supported by the “long-term program of support of the Ukrainian research teams at the Polish Academy of Sciences carried out in collaboration with the U.S. National Academy of Sciences with the financial support of external partners.”
Exploring microclimate variability across spatial scales
Authors: Hanzl Andreas , Dayal Karun , Calders Kim , Senf Cornelius
Published: March 2024

Forest microclimates play an essential role in biodiversity because they buffer temperature extremes and, thus, the impacts of climate change. Yet, our understanding of the small-scale spatial variation in forest microclimate remains vague. This knowledge gap is mainly caused by existing sampling designs capturing large-scale gradients (e.g. elevation gradients, successional gradients) instead of small-scale variation within a site. To bridge this gap, we established eight 1-hectare intensive measurement sites across a diverse gradient of Central European forests, from Atlantic lowland forests in Belgium to mountain forests in Southern Germany. Each site is stocked with 16 microclimate loggers recording temperature and soil moisture on a regular grid. We further quantified forest structure within each site using terrestrial laser scanning, offering a detailed representation of plant material distribution in all three dimensions. This setup allowed us to thoroughly examine spatial variability in microclimates within and between forest types and how variations in microclimates are linked to forest structure across variable spatial scales. Our initial findings show that logger-specific linear regressions between site-average temperature and microclimate temperature had very good fits (mean R2 = 0.98, ranging from 0.85 to 1.00). The standard deviations of regression slopes per site ranged from 0.03 to 0.11 (mean of 0.06), indicating that all sites experienced substantial variation in microclimates at a spatial scale of 20 m. Higher spatial microclimate variability was thereby correlated with higher variability in forest structure. In the next step, we will predict local microclimate variation from structural predictors (i.e. plant area index, height, canopy complexity) at variable spatial scales (from 1 to 20 m), allowing for a more detailed assessment of how microclimate variability scales across space. Hence, our research provides a new and valuable perspective on forest microclimates by specifically considering small-scale spatial variability.
Operation and developments of the Whole-Atmosphere-Model at NOAA Space Weather Prediction Center
Authors: Maute Astrid , Fang Tzu-Wei , Fuller-Rowell Timothy , Kubaryk Adam , Li Zhuxiao , Millward George , Curtis Brian
Published: March 2024

The coupled Whole Atmosphere Model - Ionosphere Plasmasphere Model (WAM-IPE) has been transitioned into operations at the NOAA Space Weather Prediction Center (SWPC) in 2021. WAM is an extension of the NOAA National Weather Service (NWS) operational model and calculates Earth’s global three-dimensional, time-dependent, neutral atmosphere from the surface up to the thermosphere at 10^-7 hPa (400-600 km). WAM is coupled to the global ionosphere-plasmasphere electrodynamics (IPE) model which extends to several Earth radii. The model is providing a forecast of the neutral and plasma environment that impacts the GNSS positioning, global communications, and collision avoidance for space traffic management.In this presentation, we describe the different Concept of Operations (CONOPS) which provide nowcast and forecast with WAM-IPE and the validation efforts. We discuss several developments based on the operational version of WAM, which includes the data-assimilation system for WAM and the high-resolution WAM-IPE. A recent testbed exercise targeted satellite operator and solicited feedback from operators and service providers which informs future developments.  We will conclude with the future plans to update WAM to the Finite-Volume Cubed-Sphere Dynamical Core (FV3) version.
Connecting climate change and health to protect the most vulnerable
Authors: Aunan Kristin
Published: March 2024

The concurrent rise in global temperatures and air pollution levels has raised concerns regarding their joint effects on human health. Heatwaves, exacerbated by climate change, have become more frequent and intense, posing significant health risks to vulnerable populations. Concurrently, air pollution, stemming from anthropogenic activities and environmental factors, contributes to respiratory and cardiovascular ailments, amplifying the health burden. It becomes important to utilize multifaceted data from climate models, demographic and socioeconomic projections like the Shared Socioeconomic Pathways (SSPs), geographical information and other pertinent datasets in exploring the complex relationship between climate change, exposure to air pollution, extreme heat and related health outcomes. Using various data sets including climate, demographic, and socioeconomic information at different scales (cohort, city, and small area levels), the recently concluded EU Horizon 2020 EXHAUSTION project quantified the synergetic effects of exposure to extreme heat and air pollution on mortality risks for respiratory and cardiovascular diseases. The project also investigated the influence of various vulnerability factors (e.g. socioeconomic conditions, access to green space) on the health risks. The heat-health burden was projected under future scenarios until 2100, taking into account shifting demographic patterns and baseline health status in various scenarios. We advocate for the extension of methodologies employed in EXHAUSTION to encompass low- and middle-income countries in South Asia and sub-Saharan Africa, where extreme occurrences of heat and air pollution prevail. The assessment of climate change impacts on human health in these regions is notably challenging due to the scarcity of data across various domains, encompassing health, climate, and socio-demographic information. We advocate for enhanced accessibility and availability of this data to deepen our understanding of the effects of climate change-induced extreme heat and air pollution on mortality and morbidity in LMICs. This improved access will better equip health officials to strategize interventions and bolster adaptation responses. Furthermore, there is a need for more detailed emission and socio-demographic projections in LMICs, underpinned by data and reflective of current trends.