bluuebunny/crossref_metadata_2025 huggingface dataset:
Interactions of geomorphology, hydrology and ecology in natural and artificial restored catchments on the Chinese Loess Plateau
Authors: Jin Zhao
Published: March 2024

The Loess Plateau of China comes from aeolian deposits and its landform evolution is sensitive to climate change and land use/land cover conversion. If without the regulation of vegetation, the relationship between loess geomorphic evolution and hydrology is mainly controlled by physical erosion processes and the catchment system does not has the function of ecosystem evolution and adaptation. From the perspective of catchment’s ecosystem management, catchment processes without any vegetation or ecological measures on the Loess Plateau of China is a rapid lateral transportation system, which can be called fast system (fast soil and water loss) and its landform change is dominated by rapid geomorphological evolution. If vegetation or ecology measures are added to the physical system, the catchment has the function of evolution and adaptation, and the elements of geomorphology-hydrology-ecology form the function of mutual feedbacks and coupling evolution processes. In this system, geomorphology regulates the distribution of hydrology, hydrology controls the distribution of vegetation, and vegetation in turn regulates the development of hydrological processes and landform evolution. Therefore, in small catchments with ecological interventions, the catchment system continues to evolve under the influence of vegetation. The surface processes will slow down under the impacts of vegetation, the geomorphic evolution will weaken, and the vertical flux of matter and energy will increase in the vegetation-regulated catchment system, which can be called slow system (slow soil and water loss). Therefore, the coupled interactions of geomorphology, hydrology and ecology is of great significance for catchment’s ecological management on the Loess Plateau of China. Overall, soil and water conservation on the Loess Plateau should not be a no-living project, but should have the characteristics of self-regulation, adaptation and evolution, and eventually form a self-stabilizing system. That is, after physical and ecological combination treatment, the catchment would be changed from a fast mass loss system to a slow mass loss system and eventually to an equilibrium system.
A slab window caused by subducted seafloor fabrics beneath North Sumatra
Authors: Hu Hao , Zhao Dapeng , Pilia Simone , Lin Jian
Published: March 2024

Slab break-off, or detachment, is a key process in the tectonic evolution of the lithosphere and underlying mantle. Even though slab break-off is commonly advocated to explain a wide range of geological observations, the mechanisms that initiate slab tearing with eventual break-off are still uncertain. Slab tearing beneath North Sumatra has been suggested from evidence based mainly on passive-seismic studies. However, the detailed slab morphology and main factors responsible for slab tearing are unknown due to a lack of convincing constraints on the properties of the subducting slab. We obtained a new 3-D high-resolution tomographic model that reveals the fine crust-upper mantle structure of North Sumatra and a well-defined, relatively low P-wave velocity channel that cuts across the subducting slab. The high-resolution images finally identified the existence of a slab window below North Sumatra, consistent with an enriched potassium content around the Toba volcano. According to the linear earthquake cluster, the location of seafloor fabric structures (such as fracture zones and fossil ridges in the Wharton basin) and the corresponding lower velocity window in our robust tomographic images, we infer that the shear stress resulting from the interaction between oblique subduction system and seafloor fabrics led a mechanism weakness in the corresponding fossil-spreading ridge, which eventually formed a slab window. The window allows the subslab materials to support the arc volcanism.
Gas sublimation through cometary surface dust mantle
Authors: Mokhtari Omar , Thomas Nicolas
Published: March 2024

Recent observations of comet surfaces have prompted a closer examination of the discrepancy between the observed amount of exposed water ice and the measured water production rates within our solar system's inner regions. The visible surface ice seems insufficient to account for the measured rates of water production. Additionally, the levels of produced gas are notably lower than what would be anticipated from the sublimation of pure water ice bodies with a similar surface area.
In light of the well-established understanding of comets' high porosity, a plausible explanation arises: the sublimation of water ice occurs beneath the visible surface. This sublimation generates gas that escapes through the pores, present within a matrix of hot dust that doesn't sublimate. This mechanism suggests that the produced gas may undergo additional heating, possibly explaining the temperatures required to match the measured terminal velocities.
To delve into this phenomenon, we've conducted an investigation using numerical models based on the Direct Simulation Monte Carlo (DSMC) method for rarified gas dynamics. Our findings reveal intriguing insights. Once the thickness of the porous layer reaches a specific size, irregularities in the source aren't discernible in the flow field. Moreover, lateral flow through this porous layer, parallel to the surface, has the intriguing effect of enlarging the apparent source size, particularly for small and isolated sources.
An important discovery is the significant increase in gas temperatures at the visible surface. These temperatures seem to mirror the distribution of temperatures within the non-volatile porous layer beneath. Surprisingly, the structural properties of this layer appear to exert only limited influence on the final gas parameters at the surface, emphasizing the complexity of this sublimation process.
Thus, our investigation sheds light on the intricate dynamics occurring beneath comet surfaces, providing a more nuanced understanding of the mechanisms driving water production rates and gas behavior within these celestial bodies.
Tracing the Origins: Investigating Anthropogenic and Natural Sources of Persistent Organic Pollutants in the Himalayan River System
Authors: Behera Diptimayee , Ambili Anoop
Published: March 2024

The primary objective of this study is to delineate the natural sources of origin of sedimentary organic matter from anthropogenic inputs of the Markanda River in India. The analysis focused on persistent organic pollutants (POPs) including polycyclic aromatic hydrocarbons (PAHs), phthalates, and linear alkylbenzenes (LABs), which are known for their high persistence, potential toxicity, and widespread occurrence. In the current global climate, characterized by an increasing recognition of environmental contamination, particularly in aquatic ecosystems such as rivers, the demand for a robust approach for the identification and monitoring of such pollution has become increasingly imperative. Our proposal aims to utilize the latest developments in biomarker analysis for the purpose of detecting, identifying, and evaluating persistent organic pollutants (POPs) inside the river system. The main objective of this study is to determine the hydrocarbon levels in different areas of the river system, including both natural and human-influenced zones. Moreover, the primary aim of this research is to ascertain potential origins of pollution by examining the associations between various categories of chemicals and patterns of land usage and cover (LULC). The investigation unveiled diverse levels of the examined persistent organic pollutants (POPs), with the mean concentration of polycyclic aromatic hydrocarbons (PAHs) at 23.4 nanograms per gram dry weight (ng/g dw), linear alkylbenzenes (LABs) at 18.1 ng/g dw, and phthalates at 8.3 micrograms per gram dry weight (µg/g dw). The observed differences in concentration levels among various places reveal the presence of spatial heterogeneity, implying that there are contributions from diffuse, nonpoint sources. The primary origins of these anthropogenic hydrocarbons may be attributed to emissions from petroleum and petroleum-derived products, industrial discharges, cultural behaviors, and the disposal of ordinary household trash and sewage. The present research offers valuable insights that may be utilized in the development of mitigation measures and the formulation of policy changes in India and on a worldwide scale. Consequently, this contributes to the wider comprehension of the anthropogenic effects on water ecosystems.
Weather-type statistical downscaling for ocean wave climate in the Chinese marginal seas
Authors: Zhao Guangfeng , Li Delei , Camus Paula , Zhang Xinli , Qi Jifeng , Yin Baoshu
Published: March 2024

A more comprehensive understanding of wave characteristics and their variability, based on reliable long-term wave data, is essential in the design, construction, operation and management in offshore and coastal applications. This study aims to downscale multivariate wave data in the Chinese marginal seas at different time scales by employing two weather-type statistical downscaling models. The calibration of both models involves the usage of historical data from ERA5 reanalysis, with sea level pressure and the squared sea level pressure gradient as the predictors and wave parameters as the predictands. The predictor definition considers the swell components in the local wave data. Both models categorize the atmospheric predictors into different weather types using the K-means algorithm (KMA), with and without regression-guided clustering (referred to as WTD-RG and WTD, respectively). Each weather type is associated with sea state parameters. The downscaled wave data from both models are validated against ERA5 data. The results show that both models can generally reproduce the wave statistics for the significant wave height, mean wave direction, mean wave energy flux, and  percentile of the significant wave height. However, the WTD-RG model performs better than the WTD model. Additionally, the ERA5 data reveal increasing trends in the mean significant wave height for most areas of the East China Sea and South China Sea and decreasing trends in the Bohai Sea, Yellow Sea, and Beibu Gulf from 1959 to 2021. These patterns are well captured by the WTD-RG model but not by the WTD model.
Macroscopic evaluation of scPDSI and SPEI links to vegetation water stress factors
Authors: Liu Qi , Yang Shanshan
Published: March 2024

The self-calibrating Palmer Severity Drought Index (scPDSI) and the multi-time-scale Standardized Precipitation Evapotranspiration Index (SPEI) are commonly employed to explore the impact of water availability on vegetation. However, their usage lacks clearly defined boundaries. This study presents a global-scale macroscopic assessment of the relationship between scPDSI and SPEI with vegetation water stress factors. Our findings reveal that, in comparison to meteorological conditions, scPDSI exhibits a stronger correlation with root-zone soil moisture (RSM). Among SPEI on various scales, SPEI at the 9-month scale (SPEI09) effectively captures RSM dynamics, while SPEI at the 1-month scale (SPEI01) is more responsive to variations in vapor pressure deficit. Moreover, the sensitivity analysis of vegetation activity response to scPDSI and multi-scale SPEI indicates higher sensitivity in drylands to scPDSI and SPEI09, while that in boreal regions of the Northern Hemisphere exhibit the highest sensitivity to SPEI01. This study will provide scientific reference for selecting scPDSI and different SPEI time scales as indicators of water availability conditions.
Smoke-weather Interaction Affects Clouds, Precipitation and Extreme Wildfires in Southeast Asia
Authors: Ding Ke , Ding Aijun , Cheng Yafang , Xin Huang
Published: March 2024

The biomass burning in Indo-China Peninsula, caused by agricultural activities, has a significant impact on human lives, air quality, ecosystems, and weather systems. However, it is not fully clear how wildfire can affect weather processes, especially clouds and precipitation formation, which are important for wildfire behaviours. Here we show that biomass burning aerosols aloft strongly increase the low cloud coverage over both land and ocean in subtropical southeastern Asia. The degree of this enhancement and its spatial extent is comparable to that in the Southeast Atlantic, even though Southeast Asia's total biomass burning emissions are only one-fifth of those in Southern Africa. We find that a synergetic effect of aerosol-cloud-boundary layer interaction with the monsoon is the main reason for the strong semi-direct effect and enhanced low cloud formation in southeastern Asia. Moreover, the interactions between smoke and weather can reduce rainfall on Indo-China Peninsula, thus worsening air pollution by enhancing fire emissions and weakening dispersion. The intricate interactions among wildfires, smoke, and weather form a positive feedback loop that substantially increases air pollution exposure.
The Neutral Air Density revolutions in the Middle Atmosphere During 2021 SSW
Authors: Yang Junfeng
Published: March 2024

The sudden stratospheric warming (SSW) is dramatic event in the winter stratosphere, during which the stratospheric temperature rapidly increases and the zonal winds reverse over the Poles. The variation of the neutral air density in the middle atmosphere during the 2021 major SSW event is investigated, using the observations from Microwave Limb Sounder (MLS), the Global Navigation Satellite System (GNSS) Occultation Sounder (GNOS) on board the Chinese FengYun 3 (FY-3) and lidar deployed in Beijing (40.3° N, 116.2° E). A rapid increase of over 50% is observed by the satellites in the mesospheric density at high latitudes around the onset date and obvious density disturbances in the upper stratosphere and mesosphere were observed by lidar deployed in Beijing (40.3° N, 116.2° E). The amplification of the zonal mean density around the onset is proportional to the latitude increase with a maximum increment above 80° N, which is more than three times larger than the climatological standard deviation. The horizontal density distributions are influenced by the changing polar vortex fields. A simulation using a specified dynamics version of the Whole Atmosphere Community Climate Model is consistent overall with the observations and presents a severe change in the planetary wave forcing and residual meridional circulation mass flux followed by a change in the density tendency. These results demonstrate that the observed enhanced density is primarily attributed to the altered planetary waves and residual circulation during the SSW event. The observations and simulations also indicate that the density anomalies could extend to middle latitudes and lead the density disturbances over Beijing.
Paleoenvironmental conditions and organic matter enrichment of the Late Paleoproterozoic Cuizhuang Formation dark shale in the Ordos Basin, North China
Authors: Shi Yuxiang
Published: March 2024

Recent years' research advance on the life evolution, oxygen content, and paleo-oceanic conditions of the Mesoproterozoic all indicate that during the Mesoproterozoic era there were suitable environments for the formation and preservation of high-quality hydrocarbon source rocks. The discoveries of the Proterozoic oil and gas resources in recent years, also suggests a need to enhance our understanding of the China's Mesoproterozoic black organic shale depositional environment and its potential for generating hydrocarbons. The Paleoproterozoic dark shale of the Cuizhuang Formation is the potential petroleum source rock in the Ordos Basin. Mineralogy, organic and inorganic geochemical analysis were applied in this study to evaluate the sedimentary paleoenvironments and its factors that control the enrichment of organic matter and to reconstruct the organic matter accumulation model of the Cuizhuang Formation dark shale. Quartz and clay minerals are the most abundant minerals in the Cuizhuang Formation dark shale. The TOC content of the dark shale is relatively fair, ranging from 0.47% to 1.47% and averaging of 1.00%, with the organic matter having a high thermal maturity (mean of 2.24 Ro%) . The Cuizhuang Formation shale was deposited in a passive continental margin setting, and the climate was under moderate warm and humid conditions with low salinity of seawater as evidenced by the proxies of chemical alteration index (CIA) and Sr/Ba. The paleoproductivity proxies Babio, Ba%, Ba/Al, P2O5 and P/Ti indicate low productivity. The low productivity may have significantly played a role in limiting the organic matter formation resulting in relatively low TOC content. The redox parameter U/Th, V/(V+Ni) and other indicators indicate that the anoxic redox environment of the dark shale is indicated. There is a significant positive correlations of V and V/Al with TOC in black shale. The anoxic redox environment in deeper waters and a higher sedimentation rate than the grey and red shale played the main role of enriching the organic matter of the dark shale. Given the widely development of the black shale, favorite depositional environment, along with the high shale TOC and suitable thermal evolution degree, the Cuizhuang Formation dark shale in the Ordos Basin is regarded as a potential source rock, holding promise for petroleum exploration.
Subpolar overturning variability from 1993 to 202
Authors: Li Feili
Published: March 2024

The subpolar North Atlantic is a region crucial for the Atlantic meridional overturning circulation (AMOC), where waters in the AMOC’s upper limb are progressively transformed into its lower limb.  Observations from the OSNAP (Overturning in the Subpolar North Atlantic Program) array since 2014 further reveal that the AMOC mostly occurs at the OSNAP East section stretching between Greenland and Scotland.  Here, we present an extended AMOC time series at OSNAP East from 1993 to 2020, using a combination of in-situ and satellite observations.  The results show a time-mean AMOC of 17.1 ± 1.8 Sv during this time period, which has substantial interannual-to-decadal variability.  To understand this variability, contributions from hydrographic and sea level changes will be discussed.
Evaluation and projection of the summer precipitation recycling over the Tibetan Plateau based on CMIP6 GCMs
Authors: Xu Ying , Han Zhenyu , Liu Yanju
Published: March 2024

Based on ERA5 and 23 CMIP6 models under three Shared Socioeconomic Pathways (SSPs), we assess the performance of CMIP6 models in reproducing the summer precipitation, evaporation and precipitation recycling ratio (PRR) over the Tibetan Plateau (TP) during 1981-2014. We also project future changes of the summer precipitation, evaporation, PRR and moisture transport over the TP during 2021-2100. CMIP6 models and their ensemble mean reproduce the temporal and spatial characteristics of precipitation, evaporation, PRR and moisture transport over the TP. And the performance in simulating precipitation is better than that in simulating evaporation and PRR. The precipitation and evaporation under the three Shared Socioeconomic Pathways (SSPs) will increase, with the significant upward trends of 0.84%/decade~2.79%/decade and 0.80%/decade~2.14%/decade, respectively. However, the PRR will increase slightly (0.13%/decade) then marginally reduce (-0.22%/decade). In the late 21st century, regional mean summer precipitation, evaporation and PRR over the TP in SSP5-8.5 will change by about 20.13%, 17.14% and -0.77%, respectively. From spatial distribution, precipitation will increase in most parts of the TP in the 21st century, especially in the western part of the plateau, reaching more than 50% in of the late 21st century, the area of PRR decreased gradually expanded, with the maximum reduction (15~20%) of PRR in the western region. It indicates that more precipitation in the western of the plateau depends on the external moisture transport. The PRR in the southern part of the plateau will increase, with a maximum of more than 20%, which indicates the contribution of the external water vapor transport to the southern precipitation will decrease, and that of the internal cycle (local evaporation) to the local precipitation will increase. In conclusion, the increase of the regional mean precipitation over the TP in the near and mid-21st century is mainly due to the local evaporation, while the increase of the summer precipitation in the late 21st century is due to both the local evaporation and the external water vapor advection, it shows that the precipitation generated by the inner circulation is becoming weaker and more dependent on the external water vapor transport.
Exploring Salinity-Linked Health Risk and Community Health Services in Coastal Bangladesh: A Way to Placed-Based Resilient Health System Approach
Authors: Hossain Md. Mahfuz , Pal Indrajit
Published: March 2024

  Saline intrusion poses a significant threat to public health in coastal Bangladesh. The study was conducted in seven coastal villages in the Gabura Union of Satkhira District in Bangladesh.  It aimed to assess the impact of water salinity on health and healthcare delivery. Data were collected from a mixed approach covering simple random sampling for quantitative data through 400 household surveys and 7 focus group discussions for qualitative data in different age groups. The findings revealed a link between salinity exposure and a range of health problems, including gastrointestinal diseases, malnutrition, respiratory infections, hypertension, pregnancy complications, low birth weight, skin diseases, and kidney diseases.  The study also illuminated the significant socioeconomic and health-related challenges faced by these communities, emphasizing the pressing need for resilient public health strategies to address the saline intrusion. Our study proposed a place-based resilient health system approach to customize public health services to the specific needs of a community.  This tailored intervention could help to mitigate the most pressing issues effectively by optimizing limited health resources despite having unique geographic challenges of this region.
Keywords: Salinity, Health impact, Coastal, Bangladesh, Place-based, Health System
Combined Effect of the Tropical Indian Ocean and Tropical North Atlantic Sea Surface Temperature Anomaly on the Tibetan Plateau Precipitation Anomaly in Late Summer
Authors: Zhang Ping , Duan Anmin , Hu Jun
Published: March 2024

Precipitation variability over the Tibetan Plateau (TP) depends largely on the atmospheric circulation pattern associated with remote oceanic forcing, while the contribution of sea surface temperature anomaly (SSTA) in different ocean basins, especially the tropical North Atlantic (TNA), remains unclear. By using multi-source data and atmospheric general circulation model, this study reveals the individual and combined effects of the Indian Ocean Basin mode (IOBM) and TNA SSTA on the interannual variability of TP precipitation in late summer (August). During the positive phase of IOBM, warm SSTA in the Indian Ocean induces an anomalous anticyclone over the Bay of Bengal (BOBAC) via the Kelvin wave–induced Ekman divergence and the resultant positive precipitation anomaly over the southeastern TP. Simultaneously, an eastward-extending Kelvin wave triggered by the positive TNA SSTA overlaps with that caused by IOBM, further strengthening the BOBAC. In addition, the Kelvin wave triggered by TNA SSTA induces anomalous easterlies over the tropical Indo-Pacific, which contribute to the warm Indian Ocean SSTA and thus amplify the IOBM affecting TP precipitation. Moreover, the positive TNA SSTA generates a westward-extending Walker circulation anomaly that is responsible for the suppressed convection over the central Pacific, which in turn triggers a Rossby wave response and further strengthens the BOBAC. As a result, the positive precipitation anomaly over the southeastern TP is strengthened significantly. Particularly, considering the 2–3-month lead time of the IOBM and TNA SSTA, the tropical SSTA can be used as a predictor for the TP precipitation anomaly.
Mg isotopic compositions of post-spreading lavas in the South China Sea
Authors: Yan Quanshu , Shi Xuefa
Published: March 2024

Post-spreading Cenozoic lavas from the South China Sea (SCS) region record some important information about the nature of underlying mantle source and deep mantle processes. In this study we analyzed Mg isotopic compositions of the post-spreading lavas collected in the SCS region. The data, together with bulk-rock major and trace element compositional data, and radiogenic isotopic data were used to indicate the origin of post-spreading volcanism distributed in the SCS region and deep geodynamical setting. We built a conceptual model for the magmatic process of post-spreading intraplate volcanism in the SCS region, and proposed that the thickness of lithosphere, as well as the involvement of recycled carbonate into their sources, are two of controlling factors for the variations of Mg isotopic compositions of lavas from the SCS region. (This study is supported by Taishan scholarship of Shandong province, Laoshan lab and NSFC).
The Importance of "FAIR by design" data in marine robotics 
Authors: Ferretti Roberta , Aracri Simona , Motta Corrado , Bibuli Marco , Bruzzone Gabriele , Caccia Massimo , Odetti Angelo
Published: March 2024

Observing, studying, and understanding processes taking place in the marine environment is now more vital than ever. The advancements in marine technology and the use of autonomous robotic platforms, give access to ground-breaking observations. Innovative robots enable the monitoring of unknown marine locations and the study of pristine habitats without influencing or modifying them. Moreover, marine robots are bridging the observational gap in marine sciences by gathering an increasing amount of unique data. These novel, non-standard robotic platforms, which include autonomous underwater vehicles (AUVs) and surface vehicles (ASVs), Remotely operated vehicle (ROV) and Unmanned Semi-Submersible Vehicle (USSV) are designed to overcome environmental limits, ensuring the safety of human operators and paving the way to the observation of challenging marine environments, such as Arctic and Antarctic regions, transitional water, and areas with very shallow water conditions, where conventional data collection methods are often ineffective.
The marine robotics group at the Italian National Research Council – Institute of Marine Engineering (CNR-INM) in Genoa has decades of experience in developing highly modular and reconfigurable autonomous robotic platforms that enable access and monitoring in critical environments and in experimental data acquisition campaigns. Moreover, the increasing use of these robotic platforms as technological enablers for innovative services is leading to the collection of large amounts of data, which require efficient management strategies for storage, historical preservation and sharing, increasing both their scientific value and their valuable utility in the development of sustainable management policies for the marine environment. The creation of common standards and infrastructure for data management, based on FAIR (Findable, Accessible, Interoperable and Reusable) principles, will allow the integration of data from different sources, including non-standard ones, making them available to a broader audience of researchers, administrators, and citizens. 
This contribution will outline the efforts of the CNR-INM group in developing and implementing a framework for the acquisition and management of combined environmental and robotic datasets, enabling the generation of integrated "FAIR by design" data. The purpose of this work, which recognizes the centrality of data through the implementation of the FAIR principles, is to facilitate the long-term preservation, sharing, and reuse of these datasets. With this new perspective in mind, it is possible to contribute actively and meaningfully to the global effort of ocean observation, supported and sponsored by the United Nations through the Decade of Ocean Science for Sustainable Development (2021-2030), crucial for the safeguarding of the entire planet.
Using ecosystem engineering for water purification – a transdisciplinary approach
Authors: Larsen Annegret , Dennis Matthew , Auberson Cecile , Angst Christof
Published: March 2024

The beaver, an ecosystem engineer, is expanding its presence in the rivers of Europe. While beaver management has traditionally focused on addressing conflicts arising from beaver damming, it has also been recognized for providing ecosystem services such as enhancing biodiversity and purifying water. In a collaborative and transdisciplinary project aimed at monitoring and managing beavers in Switzerland, policymakers, environmental managers, consultants, and scientists collaborated to quantify the ecosystem services associated with beaver damming.
The project involved a quantitative investigation, including the beaver census to determine the number and locations of beavers in all Swiss streams, identification of beaver dams, and an assessment of the impact of beaver damming on water quality across the country. In 2021, 400 volunteers and 70 game wardens underwent regional training and, following guidelines, questionnaires, and video instructions. In winter 2022 they independently surveyed 7,000 km of the Swiss river network, identifying 1,382 beaver territories with 1,316 beaver dams.
Water samples were collected upstream and downstream of all beaver-dammed river reaches in winter and summer 2022. The samples were cooled and sent by post to a laboratory for analysis. Project management and volunteer training were coordinated by the national beaver managment, part of the National Data and Information Centre for Swiss Fauna (info fauna). . An international team of scientists from Switzerland, the United Kingdom, and the Netherlands analyzed ecosystem services, with funding provided by the Swiss Federal Office of the Environment (FOEN).
The collaborative and transdisciplinary nature of the project yielded valuable datasets for river management and fundamental science. These datasets are now integrated into national online data repositories accessible to all cantonal authorities responsible for river management and restoration in order to focus efforts on  river sections with high ecosystem service value. The direct connection to national policymakers raises optimism for a shift from the current restrictive beaver management approach to a more ecosystem-service-oriented strategy. The project also provided insights into the effective involvement and limitations of volunteers through citizen science.
Land elevation change from subsidence to uplift due to groundwater decline and rebound in Taiyuan City, Northern China, analyzed with a long-term measurement from leveling and multi-sensor InSAR
Authors: Zhao Xiangjun , Tang Wei
Published: March 2024

In recent years, a comprehensive groundwater management program was adopted in Taiyuan City, Northern China, to prevent the lowering of groundwater levels and manage land subsidence due to excessive groundwater pumping in the past decades. Groundwater level from drawdown to rebound has been observed in this city following the termination of groundwater pumping. While the link between land subsidence and groundwater pumping is well documented, how the land surface responds to the recovery of groundwater after the cessation of pumping has not been studied in detail. Our study is therefore to examine the spatial and temporal evolution of land surface elevation in response to the historical groundwater drawdown and the recent groundwater recovery in more detail.We analyzed the leveling data from 1956 to 2000 to investigate changes in ground elevation in response to groundwater depletion before the termination of groundwater pumping and combined them with InSAR (Interferometric Synthetic Aperture Radar) displacement data from 2003 to 2020 to evaluate the effect of groundwater recharge after the termination of groundwater pumping. A method was proposed to merge the InSAR time series of displacement derived from multiple satellites (ENVISAT, COSMO-SkyMed, TerraSAR-X, and Sentinel-1) to achieve a consistent, long-term continuous deformation. Previous groundwater depression cones in Taiyuan (Xizhang, Wanbailin, Wujiabao, and Xiayuan) have turned into groundwater recovery and the corresponding subsidence centers have switched to land uplift. The subsidence center of Xizhang, north of Taiyuan City, experienced a total subsidence of 749 mm by Aug 2003; it then turned into an uplift with an amount rebound of 9.2% of previous subsidence by the end of 2020. In the central area of Taiyuan, the cumulated subsidence is 1127 mm in Wanbailin, 1817 mm in Xiayuan, and 3343 mm in Wujiabao. Beginning in Aug 2010, they all turned into land uplift, with a rebound of 7.9%, 4.8%, and 3.6% of the previous subsidence in each center, respectively. An analysis of the correlation between groundwater level and ground displacement suggests that the ground uplift is related to the poroelastic rebound mechanism in the porous aquifer system, which is caused by the rise in pore pressure with groundwater recovery, and the stratigraphic properties control the amount of subsidence/uplift. The findings improve our understanding of anthropogenic land subsidence and uplift in complex urban aquifers influenced by groundwater depletion and recharge and provide essential information that can contribute to future groundwater management and groundwater-related hazard mitigation in Taiyuan City.
Three Decades of Atmospheric Aerosol Measurements from AERONET 
Authors: Gupta Pawan , Slutsker Ilya , Grigorov Patar , Lind Elena , Holben Brent , Eck Thomas , Smirnov Alexander , Schafer Joel , Siniuk Aliaksandr , Sorokin Mikhail , Kraft Jason
Published: March 2024

The AERONET program is a federation of ground-based sun-photometer networks and operates in partnership with various national and international agencies, universities, institutions, research groups, and individual scientists and stakeholders. It provides worldwide observations of spectral aerosol optical depth, inversion products (microphysical and radiative properties), and precipitable water across diverse aerosol regimes. In addition, other network components enable measurements of normalized water-leaving radiance, solar flux, and marine aerosols. For the past three decades, AERONET has been providing long-term, continuous, and readily accessible public-domain datasets. The network has been growing steadily, with currently about 600 active sites. The program also supports research and application field campaigns around the world. The program continues to refine instrumentation, measurement techniques, and algorithms through research and development. The program's biggest strength is its imposition of standardized instruments, calibration, quality control, processing, and data distribution. This presentation will provide an overview of the program with examples of available datasets, current research, and applications. In this study, we will present a statistical analysis of AERONET data availability over the last three decades. The focus will be to understand measurement challenges, and identify geographical and scientific gaps. We will also highlight important upcoming satellite missions, field campaigns, and new research results from the AERONET team at NASA Goddard.
Can convection in Europa's ocean translate interior tidal heating patterns to the ice-ocean boundary?
Authors: Lemasquerier Daphné , Bierson Carver , Soderlund Krista
Published: March 2024

Several icy moons of Jupiter and Saturn, including Europa and Enceladus, host liquid water oceans buried beneath their icy crusts. Geological features of the ice crusts as well as large-scale variations of the ice thickness are often attributed to endogenic processes within the ice. However, the ice shell is also coupled to the rocky interior via the convective ocean which controls heat and material exchanges. The amount of tidal heating in Europa's silicate mantle is highly uncertain, and heterogeneous. We investigate the effect of heterogeneous tidal heating in the silicate mantle on rotating thermal convection in the ocean and its consequences on ice shell thickness. Using global direct numerical simulations, we show that, under the assumption of no salinity or ocean-ice shell feedbacks, convection largely transposes the latitudinal variations of tidal heating from the seafloor to the ice, leading to a higher oceanic heat flux in polar regions. Longitudinal variations are efficiently transferred when boundary-driven thermal winds develop, but are reduced in the presence of strong zonal flows and may vanish in planetary regimes. We investigate the impact on ice shell thickness using the conductive equilibrium model of Nimmo et al. (2007) (doi: 10.1016/j.icarus.2007.04.021). We find that if spatially homogeneous radiogenic heating is dominant in the silicate mantle, the ocean’s contribution to ice shell thickness variations is negligible compared to tidal heating within the ice. If tidal heating is instead dominant in the mantle, the situation is reversed and the ocean controls the pole-to-equator thickness contrast, as well as possible longitudinal variations.
Geoscience Knowledge Understanding and Utilization via Data-centric Large Language Model
Authors: Deng Cheng , Zhou Le , Xu Yi , Zhang Tianhang , Lin Zhouhan , Wang Xinbing , Zhou Chenghu
Published: March 2024

Large language models (LLMs) have made substantial progress in general natural language processing domains. GeoLM represents a significant stride in adapting LLMs for geoscience, with the goal of enhancing research and practical applications in this specialized area. We have developed two distinct models: a 7-billion-parameter LLM named K2, which is trained on a 5.5-billion-token geoscience text corpus that includes over 1 million pieces of geoscience literature, and a 30-billion-parameter LLM, GeoGalactica, trained on an extensive 65-billion-token corpus related to geoscience. Supported by the Deep-time Digital Earth (DDE) project, we preserve the largest text corpus specifically designed for geoscience. The efficacy of LLMs in the geoscience domain is fundamentally linked to the access to and deep understanding of extensive geoscience data. In this respect, data-centric AI is crucial. We put forward a framework, GeoLM, to tackle the challenges of data science within geosciences, integrating techniques such as information extraction, data integration, and mining. The GeoLM framework is dedicated to constructing and applying data-centric Geoscience LLMs, with the aim of enabling the wider scientific community to harness these advanced models for a more profound understanding and effective application of geoscience knowledge.
Physical modelling of steel-mesh rock revetments (mattress gabions) for coastal defence  
Authors: Stockley Alistair , Heidarzadeh Mohammad
Published: March 2024

As the rate of coastal erosion continues to increase worldwide, exacerbated by sea level rise, so too does the need for sustainable and effective coastal defence solutions. One relatively novel option is the steel-mesh cobble/rock revetment. The typology’s mesh allows for a monolithic continuity of filling material without the high embodied carbon, construction costs and large thickness that alternative revetments require. There exists a gap in physical testing of varied wave conditions meaning that: although proven in riverine environments, the use of steel-mesh cobble/rock revetments in coastal conditions has been sparse.  

With aim to further understanding of this coastal defence typology, this paper presents a 1:10 scale physical experiment under varied periodic and nonperiodic (solitary) wave conditions. Through quantitative and qualitative analysis, the steel-mesh cobble/rock revetment exhibited effective wave dissipation across a range of surf similarity parameters. It was found to significantly reduce runup when compared to smooth slopes and overall performed more effectively than its more commonly used alternative – the rock armour revetment. This performance is particularly notable as the thickness of the steel-mesh mattress is half that of the rock armour revetment. An apparent difference in dissipation mechanisms was also observed. The steel-mesh revetment exhibited absorption characteristics, whilst the rock armour produced large amounts of turbulence and aeration, indicative of reflection. Overall, steel-mesh cobble/rock revetment proved a successful and effective coastal defence solution under wave conditions. The findings of this study build upon the empirical development and should encourage further research into alternative defence solutions. 
Diffusive, Linearly-Viscous Deformation of Temperate, Watery Ice at Stresses of 50-180 kPa
Authors: Fowler Jacob , Schohn Collin , Iverson Neal , Zoet Lucas , Morgan-Witts Natasha
Published: March 2024

Where ice deforms rapidly in ice streams and outlet glaciers—either near their beds or at depth in their lateral margins—it is commonly at its melting temperature and thus coexists with significant liquid water at crystal boundaries. Hence, the need to model accurately the deformation of this watery ice is acute. We present results from ice-deformation experiments conducted to tertiary creep on the watery, temperate ice relevant to fast glacier flow. Rings of lab-made polycrystalline ice are sheared in confined compression at either controlled stresses or strain rates, with liquid water content measured calorimetrically. The size of the apparatus and the durations of experiments allow stresses, strain rates, water contents, and ice grain sizes that fall within or span ranges expected in temperate glacier ice, eliminating the common need to extrapolate experimental parameter values to glacially relevant ranges. At stresses of 180-240 kPa, we find that the stress exponent in Glen’s law is n=3.1. However, at the smaller stresses that include most ice at glacier beds and most ice-stream shear margins, 50-180 kPa, we find that sufficiently watery temperate ice (0.7–1.9% liquid water) is linearly viscous (n=1.0). C-axis orientations of ice grains after shearing cluster sub-normal to the plane of shear, and a strong shape-preferred orientation of grains develops, with grain long axes rotated antithetic to shear an average of 15° from the shear plane. To explain these observations, we propose a diffusive, micro-deformation mechanism that will be especially efficient in warm ice with sufficient liquid water: pressure-melting and refreezing at grain boundaries.
A Quantitative Quest for the Most Representative Precipitation Data Sets in Diverse Environments
Authors: Vargas Godoy Mijael Rodrigo , Markonis Yannis
Published: March 2024

The study of water distribution and movement in the Earth's atmosphere and on its surface plays a pivotal role in understanding the intricate dynamics of water resources crucial for sustaining ecosystems, agriculture, and human societies worldwide. Therefore, precipitation data becomes a linchpin, shaping the foundation for informed decision-making in water resource management and environmental planning. This study undertakes a comprehensive comparison of 20 precipitation data sets (CMAP, CMORPH, CPC-Global, CRU TS v4.07, EM-Earth, ERA5, ERA5-Land, FLDAS, GPCC v2020, GPCP v3.2, GPM IMERGM v07, GSMaP v8, JRA55, MERRA-2, MSWEP v2.8, NCEP/DOE R2, NCEP/NCAR R1, PERSIANN-CDR, PREC/L, TerraClimate), aiming to identify the most suitable data set under diverse scenarios.
Our research addresses the needs of different spatial domains, including individual countries, IPCC AR reference regions, and major river basins, with a variety of geographical features such as land cover types, elevation zones, biomes, and Köppen-Geiger climate classifications. We rigorously assess each data set's performance through a quantitative analysis, seeking to unravel reliability patterns specific to distinct regions and climatic conditions. By tailoring our recommendations to the unique characteristics of each setting, we contribute to the refinement of hydrological modeling and decision-making processes. Such efforts not only contribute to the advancement of hydrological sciences but also to the broader nexus fields, where robust precipitation data serves as a cornerstone for modeling and projecting climate change impacts.
Groundwater recharge from the Moroccan Atlas mountains and implications on current and future water resources
Authors: Ait Brahim Yassine , Berrouch Hamza , Bouchaou Lhoussaine
Published: March 2024

In northwest Africa, one of the most significant water resources is contained inside the High Atlas Mountains. But there is still a dearth of comprehensive research on the relationships between snow cover and mountainous wetlands, how their extent has changed over time and place, and how these relationships affect northwest Africa's water supplies. We suggest using a multidisciplinary approach in this research to look at the dynamics of wetlands in the High Atlas Mountains. Using isotope tracers and a range of timeframes, we want to characterize the many components of the water cycle in the area, such as evaporation, precipitation, surface water, and groundwater movement. Investigations of the relationships between snow events, snowmelt, surface water at the Lake of Ifni, and the nearby springs were conducted during a number of fieldwork and sample programs conducted throughout various seasons. Based on an altitudinal gradient and a local meteoric water line, the stable isotope data show that the lake is locally refilled by snowmelt and embedded springs. Additionally, spring water samples downstream indicate that, at the watershed level, the Lake of Ifni is the primary source of groundwater recharge outside of the winter season. Our findings demonstrate the significant role that snowfall from the Atlas Mountains plays in replenishing Morocco's primary aquifers. Future climate forecasts will highlight the importance of our research in providing hitherto unheard-of insights into Northwest Africa's water supplies. Decision-makers in the area will be able to better manage water resources and implement climate change plans with the help of our research.
Revisiting the Link between Thunderstorms and Upper Tropospheric Water Vapor
Authors: Price Colin , Plotnik Tair , Saha Joydeb , Guha Anirban
Published: March 2024

As the Earth's temperatures continue to rise due to increasing greenhouse gases in the atmosphere, a large portion of the warming is due to positive feedbacks from increasing atmospheric water vapor or specific humidity (SH). Some of this water vapor in the boundary layer is transported via deep convection to the upper troposphere (as droplets and ice crystals), moistening the upper troposphere. These small changes in SH in the upper troposphere have a significant impact on the Earth's radiation balance. We compared global daily lightning from the WWLLN data set, and SH data from the ERA5 reanalysis product for 2019, at a spatial resolution of 5 degrees. Our findings show high spatial and temporal correlations between the lightning activity and the SH concentrations in the upper troposphere. The best correlations (r2=0.72, p<<0.001) are between lightning activity and UTWV at the 200 mb level (~12 km altitude), although the correlations with SH at 300 and 400mb were only slightly lower. Lightning and SH migrate with the seasons north and south of the equator with both parameters showing maxima in the summer hemisphere around 10 degrees latitude. Furthermore, the correlation increases slightly (r2=0.73) if a one-day lag is considered between the lightning activity and the UTWV. We find that the daily global SH in the upper troposphere can be best estimated using daily global lightning frequency and a power law having an exponent of 0.33. 