bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on methodology and efficiency of microbially induced carbonate precipitation on improvement of marine silty sand
Authors: Tang Yi , Cai Shixing
Published: March 2024

The demand for ground improvement of marine sediments has been risen in construction of offshore infrastructures, including wharves, embankments and breakwaters. In recent years, microbially induced carbonate precipitation (MICP) has developed rapidly and become an alternative technology for increasing soil strength and limiting soil erosion. Silty sand is widely distributed in offshore areas throughout the world. The high salinity of seawater may have an impact on the bacterial activity, while the fine particles in silty sand would affect the transportation of cementation solution and the formation of carbonate precipitation. In this study, attentions are paid to the application of MICP on improvement of marine silty sand properties, as well as the factors influencing the hydraulic conductivity and strength of the bio-cemented soil. Multi-gradient domestication tests on Sporosacina pasteurii were carried out to ensure the bacterial and urease activities in seawater environment. It was found that the bacterial concentration and urease activity after five-gradient domestication in seawater reached 98.5% and 92.8% of those in the deionized water environment, respectively. The permeability, unconfined compressive strength (UCS) and content of carbonate precipitation of bio-cemented specimens were measured. The MICP treatment on silty sand with seawater resulted in an increase of UCS to 700 kPa and a reduction of permeability by an order of magnitude, corresponding to a carbonate content of 8%. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were performed to investigate the types and distributions of carbonate crystals. The results indicated the formation of calcium carbonate and magnesium carbonate crystals due to the interaction between carbonate ions and calcium and magnesium ions in seawater. The precipitations were distributed on the surfaces of soil particles and near particle contact points, affecting the soil microstructure and thus the strength and permeability. The influences of concentration and injection rate of cementation solution on the efficiency of MICP were demonstrated and the recommended values were given. This study may provide a possible solution for improvement of engineering properties of marine silty sand foundations.
Diurnal Temperature Variations and Thermal Tides in the Martian Atmosphere before and during Regional Dust Storms Observed by EMIRS
Authors: Fan Siteng , Forget François , Smith Michael , Guerlet Sandrine , Badri Khalid , Atwood Samuel , Young Roland , Edwards Christopher , Christensen Philip , Deighan Justin , Almatroushi Hessa , Bierjon Antoine , Liu Jiandong , Millour Ehouarn
Published: March 2024

The Martian atmosphere experiences large diurnal variations due to its small thickness and low heat capacity. Driven by diurnal solar insolation and influenced by topography and radiative drivers (clouds and dust), diurnal temperature changes propagate from lower atmosphere into higher altitudes as forms of atmospheric tides. However, our understanding of diurnal variations in the Martian atmosphere is poor due to the lack of observations, especially those covering the entire planet and all local times, until recent. In its novelly designed high-altitude orbit, instruments onboard the Hope probe of the Emirates Mars Mission (EMM) could obtain a full geographic and local time coverage of Mars every 10 Martian days (Almatroushi et al., 2021). The Emirates Mars InfraRed Spectrometer (EMIRS, Edwards et al., 2021) observes surface temperature, temperature profile, dust content, water clouds, and water vapor in the lower atmosphere. Diurnal variations of such properties are derived on a planetary scale for the first time without significant gaps in local time or interference from seasonal changes. Such a rapid full planetary-scale coverage is ideal for investigating the fast-changing dust storms on Mars. In this talk, we present results of diurnal temperature variations and thermal tides before, during, and after several regional dust storms in Martian Year (MY) 36 and 37, and their coupling with dust and clouds. The results are also compared with numerical simulations by the Mars Planetary Climate Model (PCM), providing valuable information on physical processes controlling the diurnal climate of Mars.Almatroushi, H., AlMazmi, H., AlMheiri, N., AlShamsi, M., AlTunaiji, E., Badri, K., et al. (2021). Emirates Mars Mission Characterization of Mars Atmosphere Dynamics and Processes. Space Science Reviews, 217(8), 89. https://doi.org/10.1007/s11214-021-00851-6Edwards, C. S., Christensen, P. R., Mehall, G. L., Anwar, S., Tunaiji, E. A., Badri, K., et al. (2021). The Emirates Mars Mission (EMM) Emirates Mars InfraRed Spectrometer (EMIRS) Instrument. Space Science Reviews, 217(7), 77. https://doi.org/10.1007/s11214-021-00848-
Mineralogy and P-T condition of Algoma type Banded Iron Formation from Bundelkhand Craton, North-Central India and their implications
Authors: Raza Mohd Baqar , Nasipuri Pritam
Published: March 2024

The BIFs in Bundelkhand Craton occurred as a discontinuous unit within the east-west trending Bundelkhand Tectonic Zone (BTZ). The BIFs were associated with amphibolite, calcsilicate rocks, and quartzite. The BIFs were massif in appearance in the Mauranipur (east of Bundelkhand Tectonic Zone, BTZ) that graded to layered variety in the Babina area (west of the BTZ).The Bundelkhand BIFs were characterized by 45 to 55 wt.% SiO2 and 44 to 55 wt.% Fe2O3 content. The Al2O3 content was usually low and varied between > 1 to 3 wt%. Barring a few samples, the MnO and CaO contents are < 1 wt.%. The higher MnO (~ 3.70 wt.%) and CaO (~ 1 wt.%) implied a different redox condition and involvement of CaCO3 in the early stages of BIF formations. The ΣREE content of Bundelkhand BIFs varied between 10 – 38 ppm, with Eu/Eu*SN values between 1.1 to 1.5. Geochemically, the BIFs were classified as Algoma-type BIFs deposited by low-temperature hydrothermal fluids. Monoclinic amphiboles, quartz and garnet were the dominant silicate phase for Mauranipur BIFs. Hornblende was present with monoclinic amphibole in the garnet-absent BIFs. Isolated grains of magnetite were dispersed throughout the Mauranipur BIFs. In contrast, alternate hematite and SiO2-rich layers with locally developed low-T amphiboles characterized Babina BIFs. The Fe-rich oxides were mostly hematite. Mineral microstructure and P-T pseudo-section modeling implied Minnesotaite and Fe-Ca carbonate phases were the primary minerals in BIFs, deposited at temperature ~ 200°C at 0.05 to 0.1 GPa. The primary minerals experienced dehydration and decarbonization reactions, leading to the stabilization of amphibole and garnet at a temperature of ~450°C and pressure of 0.1—0.2 GPa. When plotted in a P-T diagram, the increase in temperature corresponds to tectonic activity and plutonism, leading to micro-bock accretion and growth of Bundelkhand Craton.
Long-Term Trends of the Atmospheric Circulation and Moist Static Energy Budget in the JRA-55 Reanalysis 
Authors: Franzke Christian , Harnik Nili
Published: March 2024

The atmospheric circulation response to global warming is an important problem that is theoretically still not well understood. This is a particular issue since climate model simulations provide uncertain, and at times contradic- tory, projections of future climate. In particular, it is still unclear how a warmer and moister atmosphere will affect midlati- tude eddies and their associated poleward transport of heat and moisture. Here we perform a trend analysis of three main components of the global circulation}the zonal-mean state, eddies, and the net energy input into the atmosphere}and examine how they relate in terms of a moist static energy budget for the JRA-55 reanalysis data. A particular emphasis is made on understanding the contribution of moisture to circulation trends. The observed trends are very different between the hemispheres. In the Southern Hemisphere there is an overall strengthening and during boreal summer, also a poleward shifting, of the jet stream, the eddies, and the meridional diabatic heating gradients. Correspondingly, we find an overall strengthening of the meridional gradients of the net atmospheric energy input. In the Northern Hemisphere, the trend pat- terns are more complex, with the dominant signal being a clear boreal winter Arctic amplification of positive trends in lower-tropospheric temperature and moisture, as well as a significant weakening of both bandpass and low-pass eddy heat and moisture fluxes. Consistently, surface latent and sensible heat fluxes, upward and downward longwave radiation, and longwave cloud radiative fluxes at high latitudes show significant trends. However, radiative fluxes and eddy fluxes are in- consistent, suggesting data assimilation procedures need to be improved.
Changing impacts of tropical cyclones on East and Southeast Asian inland regions in the past and a globally warmed future climate
Authors: Chen Jilong , Tam Chi-Yung , Chueng Kevin , Wang Ziqian
Published: March 2024

The impacts of the western North Pacific (WNP) tropical cyclone (TC) on East and Southeast Asian inland regions are analyzed. Here, based on a stringent TC selecting criterion, robust increase of TC-related inland impacts between 1979 and 2016 over East and Southeast Asian regions have been detected. The storms sustained for 2–9 h longer and penetrated 30–190 km further inland, as revealed from different best track datasets. The most significant increase of the TC inland impacts occurred over Hanoi and South China. The physical mechanism that affects TC-related inland impacts is shortly discussed. First, the increasing TC inland impacts just occur in the WNP region, but it is not a global effect. Second, besides the significant WNP warming effects on the enhanced TC landfall intensity and TC inland impacts, it is suggested that the weakening of the upper-level Asian Pacific teleconnection pattern since 1970s may also play an important role, which may reduce the climatic 200 hPa anti-cyclonic wind flows over the Asian region, weakening the wind shear near the Philippine Sea, and may eventually intensify the TC intensity when the TCs across the basin. Moreover, the TC inland impacts in the warming future are projected based on a high-resolution (20 km) global model according to the Representative Concentration Pathway 8.5 scenario. By the end of the 21st century, TC mean landfall intensity will increase by 2 m/s (6%). The stronger storms will sustain 4.9 h (56%) longer and penetrate 92.4 km (50%) farther inland, thereby almost doubling the destructive power delivered to Asian inland regions. More inland locations will therefore be exposed to severe storm–related hazards in the future due to warmer climate. Long-term planning to enhance disaster preparedness and resilience in these regions is called for.
Instant weathering response to carbon-cycle perturbations during the end-Triassic extinction 
Authors: Knies Jochen
Published: March 2024

Constraints on the continental weathering feedback on carbon-cycle perturbations on northern Pangea during the end Triassic extinction (ETE) are sparse. Here, we use hyperspectral core imaging (HSI) applied to conglomeratic beds offshore central Norway which shows that enhanced degassing of basalt flows from the Central Atlantic magmatic province (CAMP) was concurrent with intense continental transformation during the ETE. We use well-constrained mercury pulses emitted in gaseous form during volcanism, and subsequently deposited in near-coastal sediments, to identify the ETE. Parallel to mercury pulses, HSI derived smectite was immediately replaced by kaolinite at the extinction level corroborating increased radiogenic run-off from the hinterland as inferred from osmium isotopes. Our new results suggest that, parallel with CAMP activity and with atmospheric carbon dioxide (pCO2) up to four times the pre-extinction level, continental weathering instantaneously intensified, providing novel empirical knowledge that can be integrated in carbon-cycle models to underpin future warming assessments.
Downward coupling mechanism of Sudden Stratospheric Warming: A Mass Flux Perspective
Authors: Son Seok-Woo , Hong Dong-Chan
Published: March 2024

Sudden Stratospheric Warming (SSW) is an important source of subseasonal-toseasonal predictability due to its significant and long-lasting impacts on surface climate. However, the mechanism of its downward coupling has not yet been fully elucidated. In this study, we investigate the downward coupling mechanism of SSW in terms of mass redistribution. Out of the 65-year dataset of the Japanese 55-year Reanalysis (JRA-55), 40 SSW events are identified. Their composite shows a significant increase of tropospheric geopotential and pressure anomalies over the Arctic (60-90°N) after the onset with a prominent surface amplification. The decomposition of tropospheric anomalies into surface pressure and air temperature components reveals that the downward coupling mainly results from surface pressure change. It is further found that surface pressure change during the SSW onset is primarily caused by the poleward mass flux near the tropopause, which is mainly driven by momentum flux change in the upper troposphere. This momentum flux change is consistent with the poleward propagation of wave, and it is may associated with the warm temperature anomalies during the SSW. These findings provide a new insight on SSW downward coupling and surface amplification.
Climate change drives rapid warming and increasing heatwaves of lakes
Authors: Wang Xiwen , Shi Kun , Zhang Yunlin , Qin Boqiang , Zhang Yibo , Wang Weijia , Woolway R. Iestyn , Piao Shilong , Jeppesen Erik
Published: March 2024

Climate change could seriously threaten global lake ecosystems by warming lake surface water and increasing the occurrence of lake heatwaves. Yet, there are great uncertainties in quantifying lake temperature changes globally due to a lack of accurate large-scale model simulations. Here, we integrated satellite observations and a numerical model to improve lake temperature modeling and explore the multifaceted characteristics of trends in surface temperatures and lake heatwave occurrence in Chinese lakes from 1980 to 2100. Our model-data integration approach revealed that the lake surface waters have warmed at a rate of 0.11 °C 10a-1 during the period 1980–2021, being only half of the pure model-based estimate. Moreover, our analysis suggested that an asymmetric seasonal warming rate has led to a reduced temperature seasonality in eastern plain lakes but an amplified one in alpine lakes. The durations of lake heatwaves have also increased at a rate of 7.7 d 10a-1. Under the high-greenhouse-gas-emission scenario, lake surface temperature and lake heatwave duration were projected to increase by 2.2 °C and 197 d at the end of the 21st century, respectively. Such drastic changes would worsen the environmental conditions of lakes subjected to high and increasing anthropogenic pressures, posing great threats to aquatic biodiversity and human health.
Molecular characterization of atmospheric water-soluble organic carbon in contrasting remote, rural, and urban environments in northern China: Comparison of normal and dust days
Authors: Wen Hui , Zhou Yue , Wang Xin
Published: March 2024

   Atmospheric water-soluble organic carbon (WSOC) is a critical component of airborne particulates, plays an important role in Earth’s energy balance, air quality, and human health. Until now, molecular composition and potential sources of WSOC in non-urban areas under different weather conditions are poorly understood in China. In this study, aerosol samples were collected at three sites in northern China representing remote (Erenhot), rural (Zhangbei), and urban (Jinan) environments during springtime. The WSOC components were analyzed by high-performance liquid chromatography coupled with high-resolution mass spectrometry. During normal days, the results showed that the numbers of assigned formulas of WSOC present the trend of urban > rural > remote sites. The CHO compounds were the most abundant formula category, followed by the CHON compounds at all three sites. The CHO compounds detected at the remote site Erenhot were dominated by oxidized unsaturated organic compounds and biomass-burning-related organic aerosol. The CHON compounds are majorly low-oxygenated-aliphatic species. All these results indicate primary anthropogenic emissions are significant sources at the remote site. However, higher contributions of highly oxygenated CHO and CHON compounds were observed at the site of Jinan, reflecting more insensitive secondary oxidation processes in the urban area. Reduced sulfur-containing species from the combustion of coal or diesel were abundant at Erenhot and Zhangbei, while the aliphatic organosulfates likely from traffic emission and nitrooxy-organosulfates from biogenetic sources were dominant at Jinan. Dust storms significantly changed the molecular composition of WSOC at Erenhot and Zhangbei. The dust-bounded WSOC was dominated by lignin-like species from plant debris, such as flavonoids. This type of organic species presents high volatility and viscosity and is likely an efficient ice-nucleating substance.
A novel high-resolution in situ tool for studying biogeochemical processes in aquatic systems: The Lake Aiguebelette case study
Authors: Grilli Roberto , DelSontro Tonya , Garnier Josette , Jacob Frederick , Némery Julien
Published: March 2024

Inland waters are a significant source of atmospheric methane (CH4), a greenhouse gas (GHG) 34-85 times stronger than carbon dioxide (on 100 to 20-yr timescales) and responsible for ~23% of global radiative forcing. Of the GHGs produced by inland waters (i.e., carbon dioxide, CH4 and nitrous oxide), CH4 is responsible for ~75% of the climatic impact of aquatic GHG emissions with aquatic CH4 emissions comparable to the largest global CH4 emitters - wetlands and agriculture. Considering that aquatic systems contribute up to half of global CH4 emissions and that CH4 is predominantly formed in anoxic environments such as lake sediments, the source and quantification of ubiquitous surface CH4 observed in most aquatic systems are a question of global importance.In this work we present the first deployment of a novel membrane inlet laser spectrometer (MILS) instrument, composed of a mid-infrared spectrometer for simultaneous detection of CH4, C2H6 and  d13CH4 coupled with a fast response (t90 < 30sec) membrane extraction system. During a 1-day field campaign, we performed a 2D mapping of dissolved CH4, C2H6 and d13CH4 of surface water of Lake Aiguebelette (France) highlighting the advantages of continuous high-resolution mapping of dissolved gases.The results showed the presence of CH4 sources less enriched in 13C in the littoral zone (presumably the littoral anoxic sediments). The CH4 pool became more enriched in 13C with distance from shore, suggesting that oxidation processes prevailed over epilimnetic CH4 production. The data obtained were in line with recent multi-lake studies.
Relative contributions of atmospheric circulation and evaporation to the faster onset of flash droughts
Authors: Gou Qiqi , Koppa Akash , Miralles Diego , Yuan Huiling
Published: March 2024

Flash droughts are characterized by their abrupt onset and rapid intensification. Identifying and quantifying the factors that trigger and accelerate the onset of flash droughts is crucial for establishing reliable early warning systems, and thus alleviate their detrimental impacts on agriculture, ecosystems, and water resources. Recent findings indicate that the combined influence of soil moisture depletion and atmospheric aridity contributes to the faster onset of flash droughts. However, the understanding of the dynamic and thermodynamic processes that expedite this rapid onset still remains limited. In this study, we utilized a drought index derived by a state-of-the-art generation of land evaporation model (the fourth version of the Global Land Evaporation Amsterdam Model; GLEAM v4.0), to investigate the spatial distribution and trends in flash drought onset speeds from 1980 to 2023. Our goal was to quantify the relative contributions of atmospheric circulation and evaporation to the trends in onset speed. Our results reveal that the transition from evaporation being energy-limited to water-limited serves as a sufficient condition for flash drought onset in humid and semi-humid regions. The onset speed of flash droughts has exhibited a significant increase since 1980, with intensified atmospheric circulation identified as a key driver for the increasing onset rates. Additionally, elevated evaporation, resulting from increased soil moisture and evaporative demand in the preceding period, emerges as the primary thermodynamic and dynamic factor expediting flash drought onset. This study enhances our understanding of the dynamic and thermodynamic drivers underlying flash droughts, contributing to the advancement of the flash drought onset mechanism. Moreover, the insights gained from this research provide valuable information for predicting flash droughts and developing strategies for effective mitigation.
Links between weather variability and Dengue outbreaks in Sao Paulo, Brazil
Authors: Naz Falak , Araújo Júlia , Oliveira Sheila , Celina Seyma , Urban Aleš , Černý Jiří
Published: March 2024

Mosquito-borne diseases are among the most dangerous threats for all people living in tropical areas. Previous research has shown that the highest incidence of mosquito-borne diseases is associated with a particular type of weather (usually wet and hot) as mosquitos’ activity and development are highly dependent on meteorological conditions. However, short-term associations (on the scale of days up to a few weeks) have been less understood.In this study, we collected weekly data on the incidence of Dengue on a municipality level in the state of Sao Paulo, Brazil, 2016–2022, and matched it with ERA5-based weather variables (ambient temperature, relative humidity, wind speed and precipitation). We employed a multilevel meta-regression analysis to i) analyse the links between Dengue incidence and weather variability in, and ii) develop a model to predict a Dengue fever outbreak based on actual weather conditions and socioeconomic variables.Our preliminary results suggest a significant association of a Dengue outbreak with above-average daily mean temperature and humidity, heavy rainfalls, and calm conditions in previous 2-6 weeks. Further analysis is needed to identify spatial differences in these patterns based on socioeconomic conditions.
Virtual outcrop models of geological structures: problems and best practices related to extraction of 3D structural data
Authors: Corradetti Amerigo , Tavani Stefano , Mercuri Marco , Bonini Lorenzo , Seers Thomas
Published: March 2024

The advancement of computer vision–based photogrammetric image processing pipelines, particularly Structure from Motion–Multi-View Stereophotogrammetry (SfM-MVS), has rapidly evolved. This evolution, coupled with the accessibility of low-cost and portable acquisition tools such as DSLR and mirrorless cameras, Uncrewed Aerial Vehicles (UAVs) and smartphones, has transformed outcrop studies in structural geology, propelling traditional field geology into the digital era. Notably, this revolution has significantly impacted Virtual Outcrop Models (VOMs), elevating them from mere visualization media to fully interrogable quantitative objects. Among the various applications of VOMs in structural geology, the extraction of near-planar features, including fracture and bedding surfaces, stands out as crucial. Numerous procedures exist for this purpose, ranging from fully automated segmentation and best-fitting of point clouds to the manual picking of 3D traces on both point clouds and textured meshes.In this work, we explore the advantages, disadvantages, best practices, and drawbacks associated with the principal procedures for extracting near-planar geological data from VOMs. While automated or supervised recognition and subsequent best-fitting of coplanar patches in point clouds have garnered significant attention, their application is generally limited to specific case studies. Geological outcrops commonly lack patches of sufficiently large near planar surfaces for robust best fitting, necessitating manual picking procedures based on visual and/or structural interpretation. In such cases, the use of textured meshes is preferred over point clouds, and consideration must be given to the accuracy of the textured mesh during digitization, as well as the intrinsic roughness of geological surfaces. The analysis of coplanarity and collinearity of picked point sets aids in identifying traces deviating from idealized configurations. However, commonly suggested threshold values often result in small datasets. Nevertheless, relying on the visual inspection of the best-fit plane and real-time computation of best-fit planes from picked point sets generally yields acceptable results, handling coplanarity and collinearity dynamically during the extraction process.
InSAR closure errors: temporal signatures and impact on deformation time series estimation
Authors: Zwieback Simon , Biessel Rowan
Published: March 2024

Closure errors quantify the inconsistency of seemingly redundant interferograms. Systematic closure errors, associated with e.g. changes in soil moisture or vegetation, can bias estimated InSAR time series. Previous work has shown that the bias can be reduced by including interferograms spanning long temporal baselines. However, it is not clear how the bias reduction depends on the temporal signatures of the closure errors and in what circumstances including long-term interferograms improves or deteriorates the InSAR phase history and ultimately deformation estimates.To identify how the temporal signatures relate to InSAR time series estimation, we introduce a mathematical framework that quantifies temporal closure signatures as a function of time and time scale. Technically speaking, we construct two complementary bases of the annihilator of the vector space of all temporally consistent phases, with each basis element extracting the closure error corresponding to the element's time and time scale. Applying this framework to Sentinel-1 observations, we find contrasting short-term, seasonal, and multi-annual closure signatures across land cover types. The inclusion of long-term interferograms is associated with characteristic changes in seasonal amplitudes and long-term trends in the InSAR phase history estimates. To determine when including long-term interferograms improves InSAR time series estimation, we formulate simple interferometric scattering models for seasonally variable soil moisture and vegetation conditions and sub-resolution deformation as is common in ice-rich permafrost. We find that including long-term interferograms improves the InSAR time series in simulation scenarios dominated by soil moisture wetting and dry down cycles. Conversely, including long-term interferograms can have a deleterious impact on InSAR time series estimates in scenarios with seasonal vegetation and sub-resolution deformation.We conclude with simple diagnostics on how temporal closure signatures and expert knowledge can inform InSAR processing to maximize deformation time series quality for a range of geohazards, including lowland permafrost deformation, landslides, and sinkholes.
Evaluating a Long Short-Term Memory(LSTM) network for real-time high-rate GNSS time series analysis
Authors: DeGrande Jensen , Crowell Brendan
Published: March 2024

We present a neural network optimized for producing GNSS displacements to explore machine learning capabilities in forecasting ground motions for earthquake early warning and to improve our understanding of ground motion in real-time. For earthquake early warning, displacements at GNSS receivers are currently being incorporated into the ShakeAlert system, but displacements in real-time are problematic due to issues with phase ambiguity fixing, cycle slips, and loss of satellite lock as well as dilution of precision from satellite network geometry. These errors can lead to anomalous motions of up to a meter. Raw GNSS observations for velocities can utilize orbits (relative positions) and remove uncertainties caused by path errors, leading to a higher precision observation than the displacements. In general, peak ground velocity is diagnostic of earthquake damage and displacement is diagnostic of total moment release, so obtaining these observations at the highest fidelity is crucial for rapid earthquake source estimation. Since processing raw GNSS velocities gives a higher precision observation, we aim to derive displacements from velocities using a machine learning approach. We use a Long Short-Term Memory (LSTM) network, a recurrent neural network (RNN) with the ability to remember values for an arbitrary amount of time, for time series prediction of the GNSS displacements. The input variables for the model are three-component GNSS velocities derived from the SNIVEL software package, with the possibility of including signal to noise and phase observables, and the output variable is the GNSS displacement time series. The GNSS displacement is validated against the displacements computed with the precise point positioning code GipsyX. With over 2250 1-Hz observations from 82 different events ranging from M4.9 to M9, we have ample data to train, validate, and test the network on. We train several neural network instances on random selection of train/validation/test split for redundancy and shuffle data input order for each instance. By computing the GNSS displacement from GNSS velocities, we produce a higher precision observation, a low-cost method for monitoring deformation without the traditionally high overhead associated with real-time GNSS processing, and the possibility of direct onboard receiver transmission of displacements.
Latent Heat Flux by Raman Lidar and Wind Lidar system during Walineas Campaign.
Authors: Summa Donato , D'amico Giuseppe , Gandolfi Ilaria , Franco Noemi , Di Paolantonio Marco , Rosoldi Marco , De Rosa Benedetto , Di Girolamo Paolo
Published: March 2024

The crucial parameter for characterizing the energy exchange between the Earth's surface and the atmosphere within the Atmospheric Boundary Layer (ABL) is the latent heat flux (LHF). This represents the speed at which energy stored as latent heat in water vapor molecules is transported into the ABL due to the turbulent convective movement of the air.The integration of both lidar measurements provides a comprehensive perspective on atmospheric processes related to latent heat flux, significantly contributing to improving the understanding of the water cycle and associated meteorological phenomena. During the WaLiNeAs campaign (Water vapor Lidar Network Assimilation), a consortium of French, German, Italian, and Spanish research groups deployed a network of 6 autonomous Water Vapor (WV) Lidars in the French territory. This network delivers measurements with high vertical resolution and accuracy throughout the Western Mediterranean, starting in the fall of 2022 and addressing critical gaps in water vapor observations in the lower troposphere from current operational networks and satellites.As part of the WaLiNeAs initiative, a Lidar system developed by the University of Basilicata was positioned near a Wind Lidar with the goal of collecting measurements of heat flux and turbulent kinetic energy (TKE). These two systems operated continuously for three months starting from the end of September 2022, covering the most favorable period in southern France and acquiring high-resolution measurements (10 seconds, 30 meters).AcknowledgmentThe authors acknowledge Next Generation EU Mission 4 “Education and Research” - Component 2: “From research to business” - Investment 3.1: “Fund for the realization of an integrated system of research and innovation infrastructures” - Project IR0000032 – ITINERIS.This work was supported by the Agence Nationale de la Recherche (WaLiNeAs, Grant ANR-20-CE04-0001). This research was also funded by the Italian Ministry for Education, University and Research (grants STAC-UP and FISR2019-CONCERNING) and the Italian Space Agency (grants As-ATLAS and CALIGOLA).References[1] Flamant, C., Chazette, P., Caumont, O. et al. (2021) A network of water vapor Raman lidars for improving heavy precipitation forecasting in  southern      France: introducing the WaLiNeAs initiative. Bull. of Atmos. Sci.& Technol. 2, 10.[2] Kiemle, W. A. Brewer, G. Ehret, R. M. Hardesty, A. Fix, C. Senff,  M. Wirtg, G. Poberaj and M. A. Lemone. (2007) Latent Heat Flux Profiles from Collocated Airborne Water Vapor and Wind Lidars during IHOP_2002. American Meteorological Society pp:627-639.[3] Behrendt , V. Wulfmeyer1 , C. Senff , S. K. Muppa, F. Späth , D. Lange , N. Kalthoff , and A. Wieser. (2020). Observation of sensible and latent heat flux profiles with lidar Atmos. Meas. Tech., 13, 3221–3233. 
Estimating the carbon footprint of post-flood urban road network restoration: A case study in Carlisle
Authors: Zhong Weichen , Howard Guy , Neal Jeffrey
Published: March 2024

Climate change and urbanization are expected to increase the risk of flood disasters in vulnerable areas. Urban road infrastructure can be affected by flooding, and subsequent restoration creates an additional carbon emission burden. These emissions are likely to compromise local decarbonization efforts, but there remains a lack of tools for quantifying the environmental impact of reconstruction projects after disasters. This study aims to develop an assessment framework to reveal the carbon footprint of post-flood road network restoration projects. The model integrates flood simulation, pavement damage evaluation, and carbon footprint calculation modules. This paper introduces nine flood scenarios ranging from 2-year to 1000-year events and a case study in Carlisle, UK, to test the integrated model. Results of the scenario simulation indicate that the carbon emissions from restoring per unit length of pavement as the flood magnitude increases for both main roads (10.46-19.21 kgCO2e) and low-volume roads (5.34-10.17 kgCO2e). Moreover, the case study indicates that the urban road network layout may significantly influence the general carbon footprint of post-flood pavement restoration. The carbon emissions from only restoring the main body of damaged pavements after this 70-hour disaster are estimated to offset almost 1% of the local decarbonization achievement for a month. Indirect carbon footprints from material production (67%) and delivery (29%) are much higher than direct emissions from on-site tasks (4%). Measures such as optimizing pavement materials, reusing wastes, rationalizing delivery routes, and improving the city layout help alleviate the burden of recovery. This study reflects on the environmental costs of disaster recovery processes, with a view to supporting improved mitigation strategies. The integrated modeling framework can also be applied to cities in different contexts to enrich reference for decision-making.
Estimating soil surface moisture in areas with high fire incidence in Serra da Canastra National Park, Brazil, using OLI and TIRS landsat-8 sensor data
Authors: César Ferreira Marcos , Carneiro Valente Danilo
Published: March 2024

The Serra da Canastra National Park (SCNP) is an important conservation unit of the Cerrado biome (Brazilian savanna) located in a mountainous area in southeastern Brazil, where the headwaters of the São Francisco River, one of the longest rivers in the country, are located. In this area, large forest fires have occurred annually, destroying native vegetation and fauna. Due to the large expanse of the Serra da Canastra National Park, firefighting in this location is a very difficult and time-consuming task. This article presents a methodological procedure for mapping soil surface moisture in areas that have shown high fire frequencies over a timespan longer than 20 years in the national park using images from the OLI (Operational Land Imager) and TIRS (Thermal Infrared Sensor) instruments onboard the Landsat-8 satellite. A soil surface moisture map was generated based on the drying of the vegetation using the temperature index calculated from a scatterplot of surface temperatures and vegetation index values in each pixel image. The vegetation index values were calculated from the normalized difference vegetation index (NDVI) algorithm using the red and near-infrared spectral bands of the OLI. The soil surface temperature was estimated using data from the TIRS sensor. We observed that areas with minimal moisture occurred on convex slopes, while areas with maximal moisture occurred on concave slopes. In addition, we found that areas with minimal moisture were more frequently located on north- and northeast-facing slopes, while areas with maximal moisture were more frequently found on south- and southwest-facing slopes. The accuracy of the soil surface moisture map was evaluated based on relative volumetric soil moisture data collected in the field using an instantaneous electronic soil moisture meter. The results of this research may contribute to the monitoring and forecasting of other areas highly susceptible to the occurrence of fire and to the planning of firefighting actions in the Serra da Canastra National Park.
Direct and lagged climate change effects intensified the widespread 2022 European drought
Authors: Bevacqua Emanuele , Schumacher Dominik L. , Rakovec Oldrich , Kumar Rohini , Thober Stephan , Schweppe Robert , Samaniego Luis , Seneviratne Sonia I. , Zscheischler Jakob
Published: March 2024

In 2022, Europe faced an extensive summer drought that resulted in severe socio-economic consequences. Combining observations and climate model outputs with hydrological and land-surface simulations, we show that central and southern Europe experienced the highest observed total water storage deficit since the observations started in 2002, likely marking the highest and most widespread soil moisture deficit since 1960. While precipitation deficits primarily drove the soil moisture drought, global warming contributed to over 30% of the drought intensity and its spatial extent via enhancing evaporation. We reveal that about 15-40% of the climate change contribution was mediated by the warming that started drying the soil before the hydrological year of 2022, indicating the importance of considering lagged climate change effects to avoid underestimating risks. Qualitatively similar effects were observed in river discharges. These findings highlight that global warming impacts on droughts are widespread, long-lasting, and already underway, and that drought risk may escalate in the future. 
Atmospheric Gas Phase Formation Mechanism of Methanesulfonic Acid
Authors: Chen Jing , Lane Joseph R. , Bates Kelvin H. , Kjaergaard Henrik G.
Published: March 2024

The oxidation of dimethyl sulfide (DMS) leads to the formation of sulfuric acid (SA) and methane sulfonic acid (MSA), which has a great impact on atmospheric aerosol and cloud formation (Barnes, Hjorth et al. 2006). Despite the great importance, the formation mechanism of MSA from DMS has remained unclear for decades (Shen, Scholz et al. 2022).           The reaction of DMS with OH radical forms methanesulfinic acid (MSIA), methane sulfenic acid (MSEA), methylation radical (CH3S) radical, and hydroperoxymethyl thioformate (HPMTF)(Berndt, Scholz et al. 2019, Shen, Scholz et al. 2022). Among them, the oxidation of the first three all undergoes either the CH3SO radical or the CH3SO2 radical as intermediates(Kukui, Borissenko et al. 2003, Berndt, Chen et al. 2020, Chen, Berndt et al. 2021).           We theoretically investigated the atmospheric fate of the CH3SO and CH3SO2 radicals. The results suggest that CH3SO radical mainly reacts bimolecularly forming CH3SO2, and the CH3SO2 radical either decomposes forming SO2 or adds O2 forming the peroxy radical CH3S(O)2OO in the atmosphere. We show that the branching ratio of SO2 and CH3S(O)2OO formation from CH3SO2 is temperature sensitive, and the ratio of SO2 to CH3S(O)2OO decreases from about 99:1 to about 95:5 when reducing the temperature from 300 K to 260K. The peroxy radical CH3S(O)2OO can react bimolecularly forming the CH3SO3 intermediate, which can abstract an H from HO2 forming MSA. In addition, we show that MSA can also form directly via the reaction of MSIA and OH followed by O2 addition (Chen, Lane et al. 2023).           Our study indicates that temperature may play a crucial role in explaining atmosphere MSA formation. SO2 is likely the dominant product from DMS + OH in the tropics and warm regions, while in the colder and polar regions, large amounts of MSA can be formed in the gas phase by DMS reacting with OH. Global modeling indicates that the proposed temperature-sensitive MSA formation mechanism leads to a substantial increase in the simulated global atmospheric MSA formation and burden (Chen, Lane et al. 2023).
Phase relations and monazite geochronology of two-pyroxene granulite and high iron oxide bearing garnet-orthopyroxene granulite from Karimnagar Granulite Belt: its importance in Neoarchean-Paleoproterozoic metamorphism
Authors: Satpathi Kausik , Nasipuri Pritam
Published: March 2024

This study reports phase relations and U – Th – Pbtotalin-situ monazite geochronology of two-pyroxene granulite and high iron oxide bearing garnet-orthopyroxene granulite from the Karimnagar Granulite Belt, Eastern Dharwar Craton, India. The two-pyroxene granulite samples with granoblastic texture are composed of quartz, plagioclase, orthopyroxene, and clinopyroxene as major mineral phases, and biotite, zircon, ilmenite, and monazite occur as accessory phases. Small anhedral coronal orthopyroxenes surround the clinopyroxene megacryst and inclusions of clinopyroxene occur in orthopyroxene. Locally, biotites overgrow orthopyroxene and clinopyroxene along their rims. Garnet-orthopyroxene granulites are composed of orthopyroxene, garnet, spinel, quartz, plagioclase feldspar, hematite-magnetite, and ilmenite. Small, rounded orthopyroxene inclusions in garnet and anhedral coronal garnets surrounding orthopyroxene were observed. Spinels are hercynitic in composition. Ilmenite and tiny grains of spinel (~30 μm) occur as exsolve phases in magnetite. Magnetite separates spinel from garnet and orthopyroxene. The following metamorphic reactions can be proposed from the mineral assemblage:Cpx megacryst + Pl = metamorphic Opx + Cpx (Two-pyroxene granulite)
(a) Opx ± Ilm + Pl → Coronal Grt + Qtz, (b) Al-rich magnetite→ Magnetite + Spinel (Hercynite), Ti-rich magnetite → Magnetite+ Ilmenite  (High iron oxide garnet-orthopyroxene granulite).
The result from petrography, phase equilibria, and thermometry of the two-pyroxene granulite predicts that metamorphic orthopyroxene becomes stable at 0.65 Gpa - 950oC along a cooling path, and biotites overgrow orthopyroxene at 650 oC (0.65 GPa). Similarly, the result from grt-opx granulite implies a cooling path where coronal garnet becomes stable at 800 oC-0.65 Gpa.The U-Th-Pb analysis of monazite grains in pyroxene (38 analysis) and feldspar (25 analysis) from two-pyroxene granulite shows the oldest and youngest peak at 2635 ± 90 Ma and 2449 ± 44 Ma, respectively. The monazite in pyroxene (46 analysis) and quartz (14 analysis) from garnet-orthopyroxene granulite exhibits the oldest peak at 2449 ± 14 Ma and a tiny youngest peak at 1987 ± 29 Ma. Another sample of garnet-orthopyroxene (40 analyses) displays the oldest and youngest peaks at 2574 ± 32 Ma and 2448 ± 25 Ma, respectively.The late Neoarchean peak at ~2600 Ma retrieved from the pyroxene granulite and high iron oxide bearing garnet-orthopyroxene granulite is probably the protolith emplacement age of granulite, correlated with the accretion of Eastern Dharwar Craton and Bastar Craton as a part of extended Ur assembly. The early Paleoproterozoic peak at ~2450 Ma implies the formation of coronal garnet and metamorphic orthopyroxene during a cooling path.
Enhanced Real-time Global Ionospheric Maps using Machine Learning
Authors: Iten Marcel , Mao Shuyin , Soja Benedikt
Published: March 2024

Accurate ionospheric models are essential for single-frequency high-precision Global Navigation Satellite Systems (GNSS) applications. Global ionospheric maps (GIMs), which depicts the global distribution of vertical total electron content (VTEC), are a widely used ionospheric product provided by the International GNSS Service (IGS). To meet the increasing need for real-time applications, the IGS real-time service (RTS) has been established and offers real-time (RT) GIMs that can be used for real or near-real time applications. However, the accuracy of present RT GIMs is still significantly lower compared with the final GIMs. IGS RT GIMs show an RMSE of 3.5-5.5 TECU compared to the IGS final GIMs. In this study, we focus on enhancing the accuracy of RT GIMs through machine learning (ML) approaches, specifically a classical Convolutional Neural Network (CNN) and a Generative Adversarial Network (GAN). The objective is to bridge the gap between the RT GIMs and the final IGS GIMs. This is achieved by using RT GIMs as input and final GIMs as target. The ML approach is applied to the IGS combined RT GIMs and Universitat Politècnica de Catalunya (UPC) RT GIMs. The performance of the improved RT GIMs is evaluated in comparison to the combined IGS final GIM.We consider over 11'000 pairs of RT GIMs and final GIMs. Over a comprehensive test period spanning 3.5 months, the proposed approach shows promising results with an enhancement of more than 30% in accuracy of RT GIMs. Especially for regions with high VTEC values, which are most critical, the results show a significant improvement. The results demonstrate the model’s great potential in generating more accurate and refined real-time maps.The integration of ML techniques proves to be a promising avenue for refining and augmenting the precision of real-time ionospheric maps, thereby addressing critical needs in the realm of space weather monitoring and single-frequency applications.
Multi-decadal changes in water mass properties of the South Indian Ocean along 110°E
Authors: Han Meng , Phillips Helen , Bindoff Nathan , Feng Ming , Patel Ramkrushnbhai
Published: March 2024

Two hydrographic voyages separated by 56 years reveal significant changes in the watermass properties in the southeast Indian Ocean along 110°E. The observations from the International Indian Ocean Expedition in 1963 and the reoccupation of the line in 2019 covered the full ocean depth from 40°S to 11°S, measuring physical, chemical, and biological properties. We focus on the physical and biogeochemical properties in watermass layers of the global meridional overturning circulation and the Indian Ocean’s shallow overturning cells.  The subtropical high salinity water (STHW), which forms the lower branch of the shallow overturning cells, has warmer and increased salinity. Subantarctic Mode Water has cooled and freshened on density levels and Antarctic Intermediate Water (AAIW) has warmed and increased in salinity. Both the SAMW and AAIW watermasses have decreased dissolved oxygen content but increased concentrations of nitrate and phosphate. The results show that changes within watermasses follow their northward pathways, suggesting influences from their formation regions, modified by interior mixing along the overturning pathways.