bluuebunny/crossref_metadata_2025 huggingface dataset:
The Estimation Model of Groundwater Hydrogeological Parameters Combining Groundwater Level Signal Analysis
Authors: Yeh Tzu-Yu , Lin Yuan-Chien
Published: February 2023

Over the past few decades, a large amount of groundwater level monitoring data has been accumulated in Taiwan, and many studies have confirmed that groundwater level changes are closely related to water resources and geological stability, and can be used as an important reference for water resources management. Compared with groundwater level observation data, it is more difficult to obtain the hydrogeological parameters. Therefore, this study takes the groundwater level of the unconfined aquifer in the Pingtung Plain, Taiwan as an example and investigates the relationship between the groundwater level and hydrogeological parameters in this area.

The groundwater level is a mixture of many different influencing factors. In order to extract groundwater level signal features and spatial distribution, We use the Empirical Orthogonal Function (EOF) and Continuous Wavelet Transform (CWT) to separate the hourly, daily, monthly and semiannual frequency signals of the groundwater level, with particle size and elevation of each station. The above information then uses stepwise regression model to pick out different aquifer impact features, base on the selected features, estimate hydrogeological parameters by using generalized additive model. The results show that time series analysis play a major role in the estimation model of groundwater hydrogeological parameters. The model proposed in this study and the feature extraction technology can effectively estimate the hydrogeological parameters of the unknown area. This study proposed a more rapid and economical method to estimate the hydrogeological parameters based on groundwater level.
Asymptomatic lithospheric drip driving subsidence of Konya Basin, Central Anatolia
Authors: Andersen Julia , Şengül Uluocak Ebru , Göğüş Oguz , Pysklywec Russell , Santimano Tasca
Published: February 2023

Geological and geophysical observations show instances of surface subsidence, uplift, shortening, and missing mantle lithosphere inferred as manifestations of the large-scale removal of the lower lithosphere. This process—specifically by viscous instability or lithospheric “drips” —is thought to be responsible for the removal or thinning of the lithosphere in plate hinterland settings such as: Anatolia, Tibet, Colorado Plateau and the Andes. In this study, we conduct a series of scaled, 3D analogue/laboratory experiments of modeled lithospheric instability with quantitative analyses using the high-resolution Particle Image Velocimetry (PIV) and digital photogrammetry techniques. Experimental outcomes reveal that a lithospheric drip may be either ‘symptomatic’ or ‘asymptomatic’ depending on the magnitude and style of recorded surface strain. Notably, this is controlled by the degree of coupling between the downwelling lithosphere and the overlying upper mantle lithosphere. A symptomatic drip will produce subsidence followed by uplift and thickening/shortening creating distinct ‘wrinkle-like’ structures in the upper crust. However, the ‘symptoms’ of an asymptomatic drip are subdued as it only yields subsidence or uplift, with no evidence of shortening in the upper crust. Here, we combine analogue modelling results with geological and geophysical data to demonstrate that the Konya Basin in Central Anatolia (Turkey) is one such example of an asymptomatic drip. Global Navigation Satellite System (GNSS) measurements reveal elevated vertical subsidence rates (up to 50 mm/yr) but no well-documented crustal strain or structural features such as fold-and-thrust belts. This work demonstrates that different types of lithospheric drips may exist since the Archean, and there may be instances where the mantle lithosphere is dripping with no distinct manifestations of such a process in the upper crust.
Nematode hitchhiking in soil bacteriophage dispersal
Authors: Mason-Jones Kyle , Dietz Cassidy , Zwart Mark , Helder Johannes , van Sluijs Lisa
Published: February 2023

Lytic bacteriophages are major drivers of bacterial mortality and biogeochemical cycles in several ecosystems, roles that have also been hypothesized in soil. Phage particles have no metabolism of their own, yet to achieve sustainable replication they must travel from one host to the next through the surrounding environment. Evidence from soil physics and phage biology suggests that this is a hazardous journey for unprotected phages, especially under the prevailing assumption that dispersal occurs by diffusion. However, many other viruses overcome dispersal challenges by taking advantage of vectors – third-party organisms that carry the virus from one host to the next. We hypothesized that bacterivorous nematodes play this role in soil, picking up phages while feeding on bacteria and transferring them to uninfected bacteria while foraging. We postulated that nematodes would provide active and directed transport of phages between bacterial patches via two possible mechanisms. First, nematode intestines could temporarily harbour infected bacteria during nematode movement. Second, nematodes could carry phages through external attachment to the nematode cuticle. Using experiments with model nematodes (C. elegans) and bacteria (E. coli, P. putida) along with phages (T7, Phi Ppu-W11) we confirmed that transfer occurs at high frequency when facilitated by nematodes, and does not occur without nematodes. Resource availability was found to influence the transfer by modulating nematode behaviour in agar, but this effect was not found in structured compost habitats. Based on these results we propose that vectors are crucial for soil phage dispersal, suggesting that phage roles in soil function are mediated by interactions with local fauna.
Delayed response of the onset of the summer monsoon over the Bay of Bengal to land–sea thermal contrast
Authors: Weihao Sun , Yimin Liu , Guoxiong Wu
Published: February 2023

The mechanisms involved in the onset of the Bay of Bengal summer monsoon (BOBSM) were studied using reanalysis data and numerical model experiments. Results revealed that the weak meridional land–sea thermal contrast (LSTC) over the northern BOB in early spring enhances the lower-tropospheric easterly belt along 10°–15°N, which is unfavorable for the BOBSM onset. The BOBSM onset is driven by the cumulative impact of this LSTC along with the LSTC in the meridional direction across the equator and in the zonal direction across the tropics, together with air–sea interactions. While the LSTC intensifies over the northern BOB, a near-surface northward cross-equatorial flow develops south of India, inducing springtime zonal flow and surface sensible heating over the southern BOB and a pair of cyclones straddling the equator over the central Indian Ocean at 700 hPa. The zonal LSTC in the tropics generates near-surface cyclones over land and anticyclones over the sea. This induces a zonal SST warm pool around 10°N, which produces vertical westerly wind shear to the north and weakens the wintertime easterly aloft and the anticyclone to its north. As the cyclone over southern India develops eastward, the cyclone below 700 hPa develops northward over the eastern BOB in response to the enhancing tropical westerly and surface sensible heating. The wintertime anticyclonic belt and easterly belt split, and the southerly carries water vapor northward over the eastern BOB, heralding the onset of the BOBSM and presenting a delayed response to the springtime LSTC changes.
Radio Instrument Package for Lunar Ionospheric Observation: A Concept Study
Authors: Watson Christopher , Jayachandran Thayyil , Kascheyev Anton , Themens David , Langley Richard , Marchand Richard , Yau Andrew
Published: February 2023

The lunar ionosphere is a ~100 km thick layer of electrically charged plasma surrounding the moon.  Despite knowledge of its existence for decades, the structure and dynamics of the lunar plasma remain a mystery due to lack of consistent observational capacity. An enhanced observational picture of the lunar ionosphere and improved understanding of its formation/loss mechanisms is critical for understanding the lunar environment as a whole and assessing potential safety and economic hazards associated with lunar exploration and habitation. To address the high priority need for observations of the electrically charged constituents near the lunar surface, we introduce a concept study for the Radio Instrument Package for Lunar Ionospheric Observation (RIPLIO). RIPLIO would consist of a multi-CubeSat constellation (at least two satellites) in lunar orbit for the purpose of conducting “crosslink” radio occultation measurements of the lunar ionosphere, with at least one satellite carrying a very high frequency (VHF) transmitter broadcasting at multiple frequencies, and at least one satellite flying a broadband receiver to monitor transmitting satellites. Radio occultations intermittently occur when satellite-to-satellite signals cross through the lunar ionosphere, and the resulting phase perturbations of VHF signals may be analyzed to infer the ionosphere electron content and high- resolution vertical electron density profiles. As demonstrated in this study, RIPLIO would provide a novel means for lunar observation, with the potential to provide long-term, high-resolution observations of the lunar ionosphere with unprecedented pan-lunar detail.
PM2.5 Reconstruction using MERRA-2 using Ensemble Machine Learning Approach and Long-term Analysis for India (1980-2021)
Authors: Kumar Vikas , Malyan Vasudev , Sahu Manoranjan
Published: February 2023

Particle exposure affects more humans globally than any other air pollutant. However, due to expensive instruments and infrastructural deficiency, a high spatiotemporal network of monitoring stations is not possible, leading to data-scarce regions. Satellite and reanalysis datasets can be implemented to estimate particulate matter, but they do not provide surface concentration and needs to be reconstructed from the components. In this study, a machine learning (ML) framework is implemented to reconstruct PM2.5 from MERRA-2 data components, namely black carbon (BC), organic carbon (OC), dust (DUST), sea salt (SS), and sulfate (SO4). The ground level and respective MERRA-2 data were collected from India's 335 continuous ambient air quality monitoring stations (CAAQMS) for 2017-2021 at hourly resolution. Random forest (RF) performs better with train and test scores (R2) of 0.86 and 0.74, respectively, while the empirical equation provides an R2 of only 0.27 on test data. The estimated PM2.5 for Indian states from 1980-2021 indicates a significant increase in most cases. However, states in the Indo-Gangetic plain such as Delhi, Punjab, Haryana, and Uttar Pradesh are the most polluted regions of India. The major shift in concentration is from 2000 onwards, which can be seen as a direct result of the economic liberalization policies implemented in 1991. The results provide evidence for the limitations of the broad application of the empirical equation and the feasibility of ML algorithms as a potential reconstruction technique for developing robust and accurate region-specific models from MERRA-2 data.
Automated Detection of Limb Clouds and Hazes by the Emirates Mars Mission (EMM) Emirates eXploration Imager (EXI)
Authors: Rothman Michael , Almansoori Alia , Brain David , Wolff Michael
Published: February 2023

The Emirates Mars Mission (EMM) has returned an abundance of whole disk images of Mars at visible wavelengths. Clouds and hazes are evident at the limb of the planet in many of these images, offering an opportunity to determine the vertical distribution of clouds on Mars over the course of a Martian year. However, there are challenges in determining the height of limb clouds due to uncertainty in the location of the Martian surface in the images. This uncertainty comes primarily from small uncertainties in the pointing of the instrument, coupled with the fact that the surface can be difficult to identify in the images due to the opacity of the atmosphere at low altitudes. With a typical pixel spanning roughly 5 km on the limb, the uncertainties in cloud height can be large. Here we present an algorithm for automatically detecting limb clouds and hazes in Emirates eXploration Imager (EXI) observations, while simultaneously detecting the location of the surface. The algorithm considers straight line ‘transects’ through the images that extend from space to the disk of the planet. The inflection point in the recorded intensity along the transect (i.e. from ‘space’ where the intensity is small, to ‘Mars’ where the intensity is large) is used to determine the location of the surface. The transect is also used to infer the presence of detached clouds, as well as surface hazes. The heights and thicknesses of clouds and hazes can be extracted from the transects. We will present the algorithm, as well as a comparison of how the results of the algorithm compare to manual analysis of EXI images. We will highlight where the algorithm does well and where it has difficulty, and how the algorithm might be used to analyze other planetary datasets.
Long-term contrasting land uses influence on soil pore structure and organic carbon
Authors: Dor Maoz , Fan Lichao , Zamanian Kazem , Kravchenko Alexandra
Published: February 2023

The advancements of agriculture practices and technologies in harnessing natural resources has been a major component of humanity's development to produce and maintain food safety. As the bed for agricultural crops, soils are a major natural resource, and soil structure plays a crucial role in agricultural productivity. Long term differences in land use and agronomic management result in differences in soil physical structure, which also translates into variations in pore networks. Decomposition of organic matter and, hence, soil carbon storage capacity are closely related to the pore domain, which is the main environment where chemical and biological processes leading to carbon protection or decomposition take place. In this study, we explored pore structure, carbon characteristics, and their relationships in contrasting ecological systems from a long-term (> 30 years) experiment located at Kellogg Biological Station (Michigan, USA). The studied systems are (i) an agricultural intensively managed system of corn-soybean-wheat rotation (CT), (ii) a native early successional community abandoned from agriculture in 1989 (ES), (iii) a mowed grassland that has never been tilled or in agriculture (NTG), and (iv) late-successional deciduous forest that has never been cleared for agriculture (DF). An x-ray tomography analysis of intact soil cores was used to investigate pore size distributions, connectivity, and morphology to assess soil pore structure. We also measured total soil carbon and nitrogen contents, mineral associated organic carbon (MAOM), and particulate organic carbon (POM), short- and long-term soil respiration, and microbial biomass carbon. Preliminary results showed that the volumes of the soil pores with 30-180 mm Ø, the size range considered as the optimal microbial habitat, followed the trend of DF>NTG »ES>CT. The nitrogen and carbon content of these systems are also in agreement with this trend. Interestingly, MAOM fraction, considered to be a more recalcitrant form of carbon, followed the same trend, while the ratio of MAOM to total organic carbon did not change notably among the systems.
Using Ancient Greek Myths to teach Geology in High School
Authors: Detsika Natassa
Published: February 2023

Ancient Greeks had myths to explain all the physical phenomena, such as thunders, earthquakes, landslides etc. I use these myths in the lesson of Geology – Geography to students at the age of 13 or 14 very often. Through the interpretation of the myths we extract meanings about the environment of the ancient ages. A myth that is directly related to the protection of the environment and the sustainability is “The myth of ERISYCHTON”. My students call it “The myth of sustainability”.THE MYTHThe giant king Erysichthon was known for his disrespect. One day he wanted to enlarge his palace to show his power. So he ordered his slaves to cut the large oaks from his Kingdom and went to the forest that was dedicated to the goddess of agriculture Demeter.Among the other trees was a tall sacred oak that was the favorite tree of the goddess Demeter and dedicated to her. Around this oak the Dryades Nymphs sang their beautiful songs and danced their magic dances. The ungodly Erysichthon did not stop his destructive work even in front of this sacred tree. However, with the first ax the priestess of Dimitra Nikippis appeared before him and tried him, but Erysichthon threatened her with his pickaxe. He grabbed an ax and said: "I do not care if this tree is loved by the Goddess. Even if she were here, they would throw her down if she stood in my way." He killed someone who tried to stop him, shouting: "Here is your reward for your pity." In the next blows of the ax, the oak, a huge tree with a thick trunk, sighed and blood flowed from the wound, and the nymph that lived inside it, dying with it, foresaw the punishment of the sacrilegious Erysichthon.The goddess Demeter asked the Hunger to visit and conquer Erysichthon and when Erysichthon fell asleep, she visited him. Erysichthon dreamed that he was hungry, and when he woke up his hunger had become indescribable. From that moment he began to eat what he found in front of him. After eating what was eatable in his house, he went out and snatch offerings from the altars. He even sent his daughter Mistra to buy food for him. In the end, Erysichthon, having nothing to eat anymore, began to eat his own flesh… until he died.INTERPRETATION OF THE MYTHWe usually say that "nature punishes". What seems to us to be punishment is the reaction that our actions provoke when they disturb the balance of its elements. Human interventions, when directed by greed and recklessness, are dangerous, whether it is the destruction of a forest or the pollution of the atmosphere, rivers, and seas. The myth symbolizes the greed, the reckless exploitation of natural resources, symbolizes the modern man who without measure consumes insatiably and above his normal needs, depriving the future of children and all her living nature and eventually eats its own flesh and is led to extinction.
Thermo-poro-elastic stress induced aperture alteration of fractured geothermal reservoir and its effect on geothermal energy production
Authors: Adhikary Shradharghya Shankar , Chaudhuri Abhijit
Published: February 2023

 Deep geothermal reservoirs are often naturally or hydraulically fractured media which consist of a rock matrix and a network of randomly oriented discrete fractures of different sizes. In the present study, a three-dimensional model of coupled flow, heat transfer and deformation of fractured geothermal reservoir is developed. Because of high thermal expansibility and high mobility, supercritical C02 is under consideration as an alternative fluid to water/brine for extracting energy from geothermal reservoir. However, for simulation of CO2 based EGS, two phase flow model should be included and this makes the coupled model far more nonlinear and complex. FEHM which is one of the most robust code developed at LANL is capable to simulate the multi-physics problem of geosciences. We have found that the computational cost for CO2 based EGS a few times higher than that of water based EGS. Due to temperature drawdown and pressure difference between injection and production wells thermo-poro-elastic stresses are induced within the reservoir. This can influence larger shear dislocation, and normal opening /closing of fracture causing changes in the fracture aperture and permeability during the extraction of the geothermal energy from a reservoir. The correlation of the variation of fracture permeability with the variation of the local stress tensor has been taken into account in this study. To study the permeability alteration on geothermal energy extraction for water and CO2  based EGS different fracture networks, different values of injection temperature and injection pressure are considered. Three-dimensional fracture networks of randomly oriented rectangular fractures with different sizes, and dip angles are created using ADFNE Matlab code. A structured computational mesh is created for simulating the multiphase flow, heat transfer and geomechanics. The nodes belonging to the fractures are assigned appropriate permeability, thermal conductivity and mechanical properties depending on the fracture aperture. The values of these properties are subjected to alteration based on local stress values.
Quantifying Coastal Upwelling Index in the Southeastern Coast of Korea
Authors: Kim Deoksu , Kim Hojin , Kwon Jae-Il
Published: February 2023

Many studies have focused on detecting coastal upwelling off the southeastern coast of Korea. Frequent occurrences of coastal upwelling are attributed to the persistent southwesterly (alongshore) wind blowing in the boreal summer season by the East Asian summer monsoon, reducing the surface water temperature by more than 5oC. Not just coastal upwelling cause variations in hydrodynamics, but it also gives rise to the primary production augmentation by phytoplankton blooms due to the supply of nutrients and fishery industry damage owing to sudden changes in water temperature. Accordingly, optimal coastal upwelling detection plays a crucial role in helping the augmentation of primary production and preventing industrial damage. Even though upwelling indices for detection are suggested, it would be inadequate to represent coastal upwelling compared with in-situ water temperature off the southeastern coast of Korea. Thus, we suggest upwelling-driven cold-water detection based on time-series observation, especially for real-time applications. By removing seasonal trends, we can define that an anomaly in sea surface temperature has occurred when the water temperature is out of natural variability (> 1σ). Furthermore, the suitability of the cold-water index was evaluated through an analysis between the index and the prerequisite when upwelling occurred, such as alongshore wind stress, wind duration, and vertical stratification.
Geological features of methane vents in the East Siberian Sea, the Arctic Ocean
Authors: Hong Jong Kuk , Choi Yeonjin , Rhee Tae Siek , Kim Sookwan , Kim Young-Gyun , Kang Seung-Goo , Jin Young Keun
Published: February 2023

The East Siberian Sea is known for its high methane emissions, and the extent of massive methane emissions in remote areas from the coast is considered an important factor in estimating total methane emissions in the Arctic Ocean. In 2021, a multidisciplinary survey was conducted on the continental shelf of the East Siberian Sea aboard the Korean icebreaker Araon. The area is in international waters and is located more than 500 km from the coast. We conducted high-resolution sparker seismic survey and sub-bottom profiling to find detailed geological structure for gas expulsion and high-frequency echo sounding using EK80 to detect gas bubbles in water column EK80. We also measured underway CH4 concentration and sampled water and sediment with CTD and a multi corer. A high methane-concentration zone was found on the very shallow continental shelf at depths of 50–70 m by the underway CH4 measurements. It is developed in a northwest-southeast direction and has a width of several kilometers in the northwest and about 50 kilometers in the southeast. Because thick sea ice remained in the southeast zone, we have to surveye in the northwest zone. During the survey, many gas flares in the echograms and gas bubbles on the sea surface were found. In the gas flare field, we conducted extensive experiments with CTDs and sediment sampling using a multi-corer. A single channel sparker seismic survey was conducted crossing the high concentration zone with a source of 3000–5000 J. The acquired data were processed to get migration section and seismic profiles show well-stratified sedimentary layers clearly. On the gas expulsion sites, the seismic profiles show many vertical faults in the shallow sedimentary layers and vertical reflections in the water column caused by the methane emission from the seafloor. Acoustic features related to gas expulsion and gas charged sediments were also observed in the SBP data. Narrow and vertical reflections are also observed in the water column above the seafloor and the location of these reflections corresponds with the edge of the high amplitude, undulated subsurface reflector at shallow depths (~5 m) below the seafloor.
Gap-filling processes for GOCI-based daily surface salinity product using environmental variables and machine learning approach
Authors: Shin Jisun , Kim So-Hyun , Jo Young-Heon
Published: February 2023

Ocean surface salinity dataset is useful for research on climate change and its variability. In particular, a gridded daily ocean surface salinity product with high spatial resolution can provide information of short-term variability in the East China Sea (ECS) and the Yellow Sea (YS). Here, we conducted gap-filling of daily surface salinity product based on the Geostationary Ocean  Color Imager (GOCI) for the period 2011-2020 with spatial resolution of 500 m using machine learning approach. For this, we used GOCI-based daily surface salinity preoduct as ground-truth data with envrionemntal variables such as sea surface temperature (SST), sea surface height (SSH), eastward seawater velocity (uo), northward seawater velocity (vo), and seawater salinity (SS) as input data of machine learning model. To identify importance between daily surface salinity and environmental variables affecting daily surface salinity, feature importance ranking was used. Our model shows gap-free daily surface salinity product based GOCI. In addition, the successful application of machine learning model provides the information of long-term variation of daily surface salinity at high spatial resolution in the ECS and the YS.
Cataloging Mesospheric Clouds using EMM EMUS/EXI Images
Authors: AlMheiri Noora , Deighan Justin , Edwards Christopher , Osterloo Mikki
Published: February 2023

Martian mesospheric clouds are observed in the Martian atmosphere around 50 to 100 km. H2O and CO2 clouds are known to form in the mesosphere. We present a systematic study of mesospheric clouds cataloged from images at a wavelength of ~180 nm acquired by the Emirates Ultraviolet Spectrometer (EMUS) instrument onboard the Emirates Mars Mission (EMM) Hope spacecraft. The study is focused on data from the mission's early Science Phase, when clouds are known to be abundant in aphelion season, and it provides insight into the distribution and pattern of mesospheric clouds, as well as showcasing corresponding near-simultaneous images of mesospheric clouds apparent in EMM’s Emirates eXploration Imager (EXI) images at a longer UV wavelength. This work is expected to provide valuable information on understanding the coupling between the lower and upper atmosphere.

 

 
Geophysical site characterization, with the tTEM system, for studies of nitrate mobilization during recharge in the Central Valley of California
Authors: Peralta Javier , Knight Rosemary , Goebel Meredith , Kang Seogi
Published: February 2023

In California’s Central Valley, the forecast from climate models is that future precipitation events will be less frequent, more extreme, and deliver a higher proportion of the precipitation as rain. The combination of these effects will challenge the state’s ability to capture and store this critical freshwater resource and will also threaten downstream communities with flooding. A water management strategy gaining popularity in California is managed aquifer recharge (MAR), where excess surface water is captured and directed to selected sites to recharge the underlying groundwater systems. AgMAR is a form of MAR where water is spread over agricultural land to recharge the underlying aquifer over short periods during the wet winter months. One concern with this strategy is the decades of intensive agriculture in the Central Valley. The intense usage of fertilizers such as nitrogen threatens to contaminate the groundwater systems on which municipalities and homeowners rely. Research into nitrate mobilization has shown that the stratigraphic characterization of a site is the dominant factor in determining the infiltration rate and mobilization of contaminants. Therefore, in order to develop a model of nitrate mobilization, detailed information is needed about surface stratigraphy. In this study, a towed-transient electromagnetic geophysical method (tTEM) was used to image the subsurface, in combination with sediment type logs, to characterize the subsurface sediments. tTEM data were acquired on a 56-ha commercial almond farm in the early spring of 2022. The tTEM data were inverted to recover a resistivity model of the site, exhibiting a high degree of spatial variability. Regions of high resistivity typically suggest coarser grained material that is more permeable and hydraulically conductive, whereas regions of lower resistivity tend to be composed of finer grained material and are less hydraulically conductive. We created a site-specific resistivity-to-sediment-type transform to extract sediment-type data from the tTEM data using data from the 1D resistivity models along with twenty co-located sediment type logs and water table measurements. Using the maximum likelihood model, we transformed the recovered resistivity model into a sediment-type model. The integration of tTEM data and well-derived information about sediment types to construct a sediment-type model can provide information about connected pathways for recharge and help inform nitrate mobilization models. This study is allowing us to develop a methodology that can be applied elsewhere for the assessment of a site for agMAR when there are concerns about nitrate mobilization. This work is in support of a larger project on groundwater sustainability in agricultural systems in the southwestern United States.
Wildfire Threats to Groundwater Supplies: Implications for Pathogen and Particulate Contaminant Transport in Porous Media
Authors: Emelko Monica , Chowdhury Omar , Sun Xiaohui , Kennington Allie , Schmidt Philip , Silins Uldis , Stone Micheal
Published: February 2023

Climate change-associated wildfires are increasing in frequency and severity, causing increasingly variable or deteriorated water quality, and challenging in-plant treatment processes beyond design and operational response capacities, to the point of service disruptions. Recent work has shown that the wildfire impacts on drinking water treatability can extend far downstream and be long-lasting. Notably, very little information regarding the impacts of severe wildfire on groundwater supplies is currently available.Wildfire transforms fuels (i.e. biomass, soil organic matter). Pyrogenic carbonaceous material formed after wildfire includes particulate ash and biochar, which often contains toxic polyaromatic hydrocarbons, dioxins and furans, as well as some heavy metals. These mobile materials may be incorporated into soil profiles (change the soil properties, e.g., hydrophobicity, pH), redistributed, or removed from a burned site by wind and water erosion to source water. While surface water treatment technologies may have some capacity to remove these contaminants from surface water, the subsurface fate and mobility of these toxic particles has not been documented and is not understood. Moreover, the implications of potential changes in dissolved organic carbon on pathogen transport in these systems has not been documented. Because groundwater-based drinking water supplies do not typically require treatment beyond disinfection, it is possible that contaminated particles could enter drinking water wells after wildfire. Moreover, NOM-associated changes in water quality may increase the risk of pathogen transport through the subsurface.Here, the impacts of wildfire on the transport E. coli and Cryptosporidium parvum oocysts in various porous media environments (e.g., particle properties, solution chemistry, organic matter character) were evaluated. Column tests were conducted using laboratory prepared wildfire ash-impacted water and wildfire impacted surface water collected after the 2017 Kenow Wildfire in Waterton, Alberta, Canada. These investigation demonstrate that under certain conditions potential post-fire shifts in water quality can substantially enhance particle/microbe transport in porous media, thereby underscoring the need to evaluate microbial risks to groundwater supplies after severe wildfire.
Carbonate formation and alteration in the salt diapir caprock (Paskhand salt diapir, Southern Iran)
Authors: Adineh Sadegh , Zavada Prokop , Heuss-Aßbichler Soraya , Bruthans Jiri , Daëron Mathieu , A. Petrash Daniel
Published: February 2023

The eastern Zagros Fold and Thrust Belt (ZFTB) in Iran includes a salt tectonic province with roughly 130 salt-gypsum diapirs emerging within the Neoproterozoic-Early Cambrian Hormuz Complex. The diapirs in the ZFTB differ in composition and in their distribution of exposed caprock mélanges (CRMs). Although there are numerous studies focused on the geochronology and geochemistry of igneous rocks as exotic blocks associated with CRMs, the geochemistry, and petrography of carbonates remain to be systematically investigated. The Paskhand Diapir is a unique little diapir with no visible salt rock at the surface. Its CRMs consist of massive and layered gypsum, carbonate, marlstone, and siltstone,  which are associated with diabase exotic blocks. The carbonate paragenesis is being examined. A grey fine crystalline  dolomite is considered to have originated early during diagenesis from a Neoproterozoic marine environment. Other carbonates can be distinguished on the basis of their microspar, and spar cements. In general, the major minerals are dolomite and calcite, with quartz and iron oxides being in minor abundance. Important trace minerals are pyrite, sphalerite, talc, mica, K-feldspar, malachite, bassanite, rutile, chlorite, and apatite. Their abundance in mineral assemblages is variable, also depending on the locality within the diapir. Later-stage calcitic veins frequently cross-cut through micritic and microspar cemented lithologies. Lithological mapping shows that the edge of the diapir commonly exhibits a greater variety of mineralization modes with extensive recrystallization as compared with its core. The δ13C values of dolomite range from –7.0 to +2.7 ‰ V-PDB. This range indicates that seawater was the principal source of reactants for dolomite precipitation, although with some inorganic carbon derived from organic matter oxidation. The δ18O values of dolomite range from –0.55 to –13.13‰ V-PDB, reflecting a temperature fractionation effect. The carbonate formation temperatures of the Hormuz complex (both veins and host rock) were determined for the first time by using the Δ47 (paleo)thermometer in dolomite. Δ47 values range between 0.422 ± 0.015 and 0.287 ± 0.015 ‰, indicating diagenetic closure temperatures of between 116.4 ± 11.7 and 271.2 ± 32.5  ºC. An intensive interaction of hydrothermal fluids with the host rock during localized carbonate recrystallization is thus evidenced.These results show that a correct interpretation of the mechanism(s) of carbonate alteration is critical for reconstructing the history of diapirism in the area. We hypothesize that carbonates in CRMs were reworked through a series of events largely influenced by thermochemical sulfate reduction (TSR) at T ≥ 110 ºC.   
Decoupling of Rub’ al Khali Quaternary dune record and paleoclimate
Authors: Gunn Andrew , Ewing Ryan , Brown Josephine
Published: February 2023

The climate history of wind-blown dune fields is commonly determined by dune morphology, stratigraphy and age. These properties in the Rub’ al Khali have been used to interpret climate history relevant to human dispersal and monsoon variability during the glacial cycles. An underlying assumption of some of these interpretations is that the time it takes dunes to respond to a change in climate is shorter than the time over which climate changes. Here we show that this assumption does not always hold. We do this by comparing the bedform reconstitution time Tr (i.e., the time taken for sand to be completely reworked within a dune) to a climate persistence time Tc (i.e., how long dune-relevant wind properties stay the same). Tr is found using modern wind reanalysis and topography data, and Tc using paleoclimate simulations. Where Tr>Tc, climate varies too fast to be recorded in dune properties. In some areas of the Rub’ al Khali, Tr is longer than the time between glacial cycles, so dune properties and modern climate are decoupled. We extend this case study to a general theory to assess if wind-blown dunes properties can be used to interpret past climate.
Ground motion amplification due to lunar topography
Authors: Yellapragada Meenakshi , stg Raghukanth
Published: February 2023

In recent years, estimating the possible ground motion on the Moon became quite essential as various researchers are exploring safe extra-terrestrial habitats close to the Earth. From the high-resolution imageries, it is observed that seismic sources like lobate scarps and wrinkle ridges are identified representing that there is seismic activity on the Moon which is considered a hazard to the lunar base. Therefore, it is essential to include topographic amplification factors in the ground motion predictions on the Moon which are in turn used in the seismic hazard analysis. It is well known that there is a wide variation of topographical features in the lunar south pole region (LSPR). Hence in this study, the spectral element method is preferred to model the seismic wave propagation in such complex topographic regions. The main objective of this study is to estimate the ground motion amplification on the Artemis landing sites that are present in the LSPR region. The topography for the study region is extracted from the entire South-pole topographic map which is obtained from the LRO-LOLA. A grid elevation data is incorporated with a resolution of 30m. The shallow moonquake event that occurred on March 13, 1973, is considered a seismic source, located at [84⁰ S, 134⁰ W] and has a focal depth of 5 km. The seismic wave simulations can generate up to a frequency of up to 2Hz from the developed model. The simulations have been performed with and without topography. The amplification ratio i.e., Peak ground displacement with topography/ Peak ground displacement without topography is calculated for the considered landing sites. In addition, an amplification map of the shake intensity maps is also generated for the considered study region. Results show that there is amplification on ridges and de-amplification in the valleys.
Cause of the cold condition over northeast Asia in April 202
Authors: Kim Go-Un , Oh Hyoeun , Kim Yong Sun , Son Jun-Hyeok , Jeong Jongmin , Jeong Jin-Yong
Published: February 2023

Although northern Asia's temperature was the fourth highest on record, Northeast Asia was severely damaged agricultural and marine products due to the cold condition in April 2020. Previous studies have shown that the dipole atmospheric circulation over Siberia and the East Sea (also referred to as the Japan Sea) rendered this cold environment. Here we show that the atmospheric structure affecting the cold condition over northeast Asia was a mixed result of the East Atlantic/Western Russia (EAWR) pattern and blocking. The wave train was originated from the vorticity forcing of northwest/central Russia and propagated toward the southeast via the climatologically westerly and northerly flows. Furthermore, the blocking days over Siberia increased approximately ten times in April 2020 than climatology along with the easterly anomaly over Mongolia–northeast China. The blocking occurrence might be connected to wavy westerly at the high latitudes. The strong blocking and EAWR pattern led to the robust dipole atmospheric structure with the prevailing northerly wind in April 2020, thereby causing the cold over northeast Asia. Our results help to understand the cause of the cold condition in April over northeast Asia and its impact on the land and ocean ecosystems.
Earth system model sea-ice loss experiments are wrong. Are they useful?
Authors: Kushner Paul , Fraser-Leach Luke , Audette Alexandre
Published: February 2023

Our poor understanding of how the Arctic’s atmosphere, sea ice, and ocean are coupled limits what we can say about Arctic change from greenhouse warming, and what Arctic change means for global weather and climate. Earth system models that simulate Arctic and global change, while complicated and imperfect, are useful to understand drivers of Arctic change and its global influence. In the virtual world of models, you can remove Arctic sea ice and analyze its local and remote response, without greenhouse warming. Or, you can keep sea ice unchanged and investigate a virtual world of greenhouse warming without sea ice loss. But this virtual exploration can fool us: recent work by Mark England and colleagues has shown that this kind of sea ice removal, when carried out in the setting of coupled ocean-atmosphere models, artificially amplifies Arctic warming, with global implications. The basic problem is that these simulations use Arctic sea ice loss as a stand-in for Arctic warming, but targeted ice loss does not account well for the effect on the Arctic of greenhouse warming. We confirm the England et al. result but argue that sea ice loss experiments can nevertheless provide physically reasonable results, if they are linearly combined with greenhouse warming experiments using scaling suggested by simple energy balance models. This post-processing step, along with refined methods for inducing sea ice loss, allows us to gain value from sea ice loss experiments and avoid some of the difficulties arising from interpreting these experiments at face value. 
Geophysical investigation of kurgans in Uzun Rama steppe, Goranboy region, Azerbaijan
Authors: Bayramov Kamal , Jodry Clara , Alizada Gunel , Mammadov Sarvar , Azimov Vusal , Abdullayev Malik
Published: February 2023

Kurgans are funeral chambers, evidence of burial tradition dating back to the first thousand years BCE, of nomadic populations that covered a vast area in-between Europe and Asia. In Azerbaijan, past archaeological explorations revealed numerous large kurgans from the Early Bronze, which correspond to Kura-Arexed period (ca. 3500-3000 BCE), and relatively smaller burials of Late Bronze/Early Iron Ages. To improve the efficiency of the excavation process, geophysical methods have been widely and effectively applied for many years to provide clear and useful images of archeological targets hidden underground such as kurgans.In this work, we introduce a multi-method archaeo-geophysical survey done in May 2022 to investigate Early Bronze Age kurgans located in Uzun Rama Steppe of Goranboy region in Azerbaijan. Applied method cover different depth of investigation and resolution to provide a wealth of information on the structure of three kurgans aligned in a North-South direction. It comprises coincidental DC-resistivity and seismic refraction tomographies of 70.5 m with a 1.5 m spacing going over all kurgans, a Ground Penetrating Radar (GPR) 40 m long profile using a 500 MHz antenna on the northern kurgans going from East to West and a magnetic map 24 x 25 m on the southern one.The DC-resistivity profile shows two layers, a medium resistivity layer (500 to 600 W.m) from the surface to 6 m depth and a very conductive layer (> 10 W.m) under it. The first layer contains three areas of lower resistivity (~ 60 W.m) that are limited in thickness and length. As these three spots are marked by higher height on-site, we interpret them as the three kurgans. The coincidental seismic profile is a lot less detailed (due to physical properties and higher spacing between receiver) and define only three homogeneous layers, a first layer from the surface to 1 m depth with a P-wave velocity of 300 m/s, a second layer of higher velocity (1000 m/s) from 1 m depth to approximately 6 m depth and a final third layer of 2000 m/s velocity. Even though, the resolution is lower, we interpret the first layer as an attempt of the model to represent the kurgans. The GPR profile give a high attenuate image due to low resistive layer. However multiple diffractions can be seen in the first meter of the subsurface that can indicate the presence of ancient artefact related to the kurgans. Finally, the magnetic map defines the limit of the kurgan as a positive-negative anomaly probably due to the burning ritual that ended the implementation of a kurgan.This geophysical campaign allowed us to accurately locate the kurgans as well as provide information on the environment. DC-resistivity and magnetic mapping seem to get the best results in our case. A future archaeological investigation will be put in place based on these results.
Upper Arctic Ocean Properties and Relationships with Sea Ice in CMIP6 Historical Simulations
Authors: Cheng Wei , Bitz Cecilia , Roach Lettie , Blanchard-Wriggleworth Edward , Bushuk Mitch , Wang Qiang
Published: February 2023

While current-generation CMIP and OMIP models have clear biases in their upper Arctic Ocean hydrography, it is less clear how these biases impact the models' ability to simulate the observed Arctic sea ice mean state and trends. In this study we seek to quantify cross-relationship between sea ice and ocean states in CMIP6 historical simulations and identify common model behaviors. Multi-model mean (MMM) simulations exhibit accelerated changes in the ice and ocean system since the late 20th century. Underlying the MMM is strong inter-model variation in the simulated ice and ocean mean states and their temporal variability including trends. Despite such inter-model differences, all models show a similar ratio between sea ice reduction and upper ocean warming such that models with higher ocean warming also have higher SIE reduction and vice versa. Our results also highlight the urgent needs of reliable Arctic Ocean observations or data products in order to better contextualize modeling results.
Rainwater infiltrating process revealed from the self-potential signatures, insight for landslide monitoring
Authors: Hu Kaiyan , Huang Qinghua , Han Peng , Zhang Yihua , Mo Chunyu , Jougnot Damien
Published: February 2023

Understanding the physical process of soil imbibition and water flow in the porous media in depth is significant in assessing the risk of forming landslides. Volumetric soil moisture sensors can be used to measure water content variations in situ. However, it has a spatial gap due to the limited number of installed sensors. On the other hand, geophysics can provide integrated measurements that can be spatially resolved. Among existing geophysical methods, Self-Potential (SP) is a method of choice to monitor water flow. Indeed, pore-water flows can generate the electrical streaming current based on the electrokinetic mechanism. This electrokinetic cross-coupling process is not only sensitive to the water flow but also depends on water content variations. This study relies on a soil-column experiment by artificially imposing rainfall to examine if the electrical SP could indicate the water infiltrating process. Combined with the observed data, our results indicate the water infiltrating stages can be characterized by the extracted SP signatures under a comprehensive numerical model. As a passive hydrogeophysical method, the capacity of SP to capture the characteristics of the spatio-temporal variations of water fluxes and soil-water conditions can offer early warning information of rainfall-induced landslides.