bluuebunny/crossref_metadata_2025 huggingface dataset:
A dynamical separation of deep and shallow branches in the stratospheric circulation
Authors: Baikhadzhaev Rasul , Ploeger Felix , Preusse Peter , Ern Manfred , Birner Thomas
Published: February 2023

The Brewer-Dobson circulation is the wave driven meridional circulation of the stratosphere it plays an important role in determining the transport of trace gases and aerosols within the stratosphere, affecting the lifetimes of ozone depleting substances, and the global radiation budget. The overturning part of the circulation is usually split into a deep and a shallow branch. Here, we investigate the dynamical driving of these circulation branches, aiming for a dynamical separation of different circulation regimes.For that purpose, we use data from fifth generation atmospheric reanalysis ERA5 by the European Centre for Medium-range Weather Forecasts (ECMWF) and apply the Transformed Eulerian Mean approach to estimate the overturning mass flux and the related wave forcing in the stratosphere. We find that reducing the horizontal resolution of the data from 0.3 to 1 degree does not affect results significantly. However, reducing temporal resolution from 1 to 6 hours has a significant effect on the structure of daily mean upwelling, but this effect is much less pronounced for monthly means. Eliassen-Palm flux divergence is used as a diagnostic to estimate the wave propagation in the stratosphere. Using Fourier transformation for spectral decomposition we estimate the contribution from different waves to the driving of the deep and shallow branches. In particular, it is found that the deep branch has a strong seasonality with maximum in winter, while the shallow branch is less affected by the change of seasons. On the one hand, we find a strong correlation between variability in residual circulation velocity along the deep branch and large scale waves with wavenumber 3 or smaller. On the other hand, variability of medium and small scale waves with wavenumber 4 or greater correlates strongly with variability in the shallow branch circulation velocities. The change between these two dynamical regimes happens at a level close to 37 hPa. These results were further tested by applying a downward control calculation, showing that indeed the large-scale, planetary waves (wavenumber less than 4) account for the largest part of deep branch variability, while smaller waves (wavenumber larger than 3) account for the largest part of shallow branch variability. Based on these results, we propose a physical definition of the different Brewer-Dobson circulation branches, with the deep branch defined as driven by planetary waves (wave numbers 1-3) and located above 35 hPa, whereas the shallow branch being located below that level and driven by smaller-scale waves (wave numbers 4 and greater).  
Hydrogeological Change in Borehole Damage Zone (BDZ) by Expanding Diameter of Borehole
Authors: Park Kyung-Woo , Park Byeong-Hak , Ji Sung-Hoon
Published: February 2023

This presentation describes the results of a study on the change in hydrogeological properties that can occur in natural barriers after excavating a disposal hole. We performed a series of hydraulic tests at a borehole in the KURT area to understand the change in the hydrogeological characteristics around the drilling-induced damage zone after excavating the disposal hole. As a result, it was confirmed that the transmissivity of fractured rock was increased from several times to tens of times. It was caused by the drilling-induced damage generated around the borehole surface by expanding the diameter of the borehole. In particular, the change in transmissivity was increased in the test section with low transmissivity. In the end, the permeability in the borehole damage zone had a high transmissivity overall, and the hydraulic connection within the borehole damage zone was expanded. Additionally, it was confirmed that the range of hydrogeological influence of the borehole damage zone decreases as the distance from the borehole hole. The results, which analyzed the hydrogeological effect of the borehole damage zone by the borehole expansion, differ in size from the actual disposal hole in the repository. However, compared to large-scale research on an excavation damage zone conducted in tunnels, researchers can easily access it. Therefore, it will be used in various studies to analyze qualitative phenomena.
Large bushfires under drought and extreme temperature conditions in southeastern Australia: a probabilistic assessment using copulas
Authors: Páscoa Patrícia , Gouveia Célia , Russo Ana , Ribeiro Andreia
Published: February 2023

The occurrence of large bushfires in southeastern Australia has been linked to the occurrence of extreme climate conditions, such as droughts and extreme temperatures. Several extreme bushfires have occurred following or during severe droughts and heatwaves, namely the Black Saturday bushfires in 2009 and the Black Summer of 2019-2020. Fire-prone weather conditions have become more severe in this region during the past years and are expected to worsen as the frequency of compound drought and extreme temperature events is expected to increase in the future, even under lower emission scenarios. This is particularly important as the impacts of compound climate events are usually larger when compared to the impacts resulting from an individual event. Therefore, compound drought and temperature extremes are likely to increase the probability of large bushfires, compared to the occurrence of an individual event.In this work, the trivariate relationship between burned area in the months of December to February, drought conditions, and temperature extremes was analyzed using copulas for the period 2001-2020. Burned area across forests were computed using the GlobFire dataset. Drought conditions were assessed using the Standardized Precipitation Evapotranspiration Index (SPEI), computed with monthly precipitation and temperature data from the CRU TS4.05 dataset. The indices Number of Hot Days (NHD) and Number of Hot Nights (NHN) were used to identify conditions of extreme temperature and were computed using hourly temperature data from ERA5. The influence of concurrent and previous climate conditions on the burned area was assessed, for up to 3 months before the beginning of the fire event.The results show a clear influence on the probability of occurrence of large fires under conditions of drought and extreme temperature. Drought conditions in the months before the fire event had a larger effect than temperature extremes. Moreover, the probability of occurrence of large fires is higher when compound drought and hot events are present than given only one individual extreme event. Acknowledgements: This study was supported by the H2020 FirEUrisk project (EU H2020, Grant Agreement 101003890) and by FCT (Fundação para a Ciência e Tecnologia, Portugal) through national funds (PIDDAC) – UIDB/50019/2020 and project Floresta Limpa (PCIF/MOG/0161/2019).
Metagenomic insight into methanogenic pathways in seagrass sediments
Authors: Dai Guiyuan , Chen Xiaogang , Cui Lijun , Zhuang Guangchao , Ju Feng , Li Ling
Published: February 2023

Methanogenesis is important to the net carbon burial capacity in seagrass sediments. This microbially driven biogeochemical process can be fulfilled via three main pathways: hydrogenotrophic, acetoclastic and methylotrophic methanogenesis. However, the relative importance of each methanogenic pathway in seagrass meadows is poorly reported. In marine sediments where sulfate is abundant (15-43 mmol/L), hydrogenotrophic and acetoclastic methanogenesis are usually inhibited because of the competition for methanogenic substrates including hydrogen and acetate by sulfate-reducing bacteria. Thus, methylotrophic methanogenesis is hypothesized to play a crucial but yet-underappreciated role in the carbon cycle. In this study, culture-independent metagenomic approaches were used to profile the methanogenic pathways in seagrass sediments. Based on the functional potential analysis, methylotrophic methanogenesis is revealed as the dominant pathway in the seagrass sediments. Based on the metagenome-assembled genome analysis, Methanococcoides, which harbors known methylotrophic methanogens, is the only detected genus of methanogens in the seagrass meadow metagenomes. In the bare sediment, the abundance of Methanococcoides in the bottom was 41% higher than that in the surface due to the low oxygen in the bottom. While in the sediment covered by seagrasses, the abundance of Methanococcoides in the surface was 43-82% higher because of the higher fresh organic carbon content, which provides abundant substrates for methanogens. These findings reveal the methylotrophic methanogenesis is the main methanogenic pathway in both bare sediments and sediments covered by seagrasses. The hydrochemical analysis further suggested that in bare sediments, the methanogenesis was mainly controlled by oxygen content. However, in seagrass sediments, the availability of substrates was the dominated factor.
STELLA—Potential European contributions to a NASA-led interstellar probe
Authors: Wimmer-Schweingruber Robert F. , André Nicolas , Barabash Stas , Brandt Pontus C. , Horbury Timothy S. , Iess Luciano , Lavraud Benoit , McNutt, Jr. Ralph L. , Provornikova Elena A. , Quémerais Eric , Wicks Robert , Wieser Martin , Wurz Peter
Published: February 2023

Stella is a proposed European contribution to NASA’s Interstellar Probe (ISP), a large-strategic mission candidate. ESA’s call for M-class mission proposals was the best and only currently available option for the European science community to contribute to the astronomically constrained ISP launch window in 2036 – 2037. Traveling with a speed of ~ 7.0 au/year ISP would reach 350 au during its nominal 50-year life-time. The proposed Stella contribution to ISP includes two core and two optional elements for the full complement:• Core: Provision of European scientific instruments;• Core: Provision of the European ISP communication system including the spacecraft’s 5-m high gain antenna;• Full complement: ESA deep space communication facility: an extension of ESA’s DSA with a new antenna array;• Full complement: Contribution to ISP operations to increase drastically the ISP and European payloads science return.
Dynamics and facies analysis of Mid-Late Holocene reef systems in French Polynesia
Authors: Hallmann Nadine , Camoin Gilbert , Eisenhauer Anton , Samankassou Elias , Vella Claude , Botella Albéric , Milne Glenn , Humblet Marc , Braga Juan Carlos , Fietzke Jan , Goepfert Tyler
Published: February 2023

The detailed reconstruction of reef geometry, composition and evolution during the mid-late Holocene brings valuable information regarding coral reef dynamics and coastal processes during periods of higher sea level and wave energy regimes.This study provides a high-resolution reconstruction of the reef growth history in French Polynesia and their response to low-amplitude, high-frequency relative sea-level (RSL) changes and associated environmental changes over the past 6,000 years. After the stabilisation of sea level at its present position, the newdevelopment of reef systems was initiated by the creation of accommodation space due to a glacio-eustatic sea-level rise from 6.0 to 4.1 kyr BP, and controlled by the antecedent topography of the islands. A single,short-lived sea-level highstand of less than one metre between 4.1 and 3.4 kyr BP is documented preceding a fall in sea level between 3.6 and 1.2 kyr BP. The reported RSL changes are characterized by slow rates ranging from a few tens of millimetres per year up to 2.5 mm/yr and by significant sea-level stability (stillstands) lasting more than a century and up to 250 years, defining a step-like pattern.Regionally, the persistence of stable and optimal depositional environments over the last 6,000 years is demonstrated by the constant overall composition and diversity of reef communities and the almost continuouswidespread development of microatoll fields and reef flat units. The facies distribution as well as the lateral extension and shift of facies belts have been governed by variations in accommodation space, which are controlled by RSL changes and antecedent topography. The recurrent sea-level stillstands that punctuated the mid-late Holocene sea-level history have played a significant role in the development of dense reef frameworks.The widespread development of mid-late Holocene reef deposits in coastal areas, especially reef flat units and storm conglomerate deposits, suggests that they have played a prominent role in the formation and shaping of modern islands and islets, creating significant topographic features that formed the foundations of these islands.
More microbial manipulation and plant defense than soil fertility for biochar in food production: A field experiment of replanted ginseng with different biochars
Authors: Liu Cheng , Pan Genxing
Published: February 2023

The role of biochar-microbe interaction in plant rhizosphere mediating soil-borne disease suppression has been poorly understood for plant health in field conditions. Chinese ginseng (Panax ginseng C. A. Meyer) is widely cultivated in Alfisols across Northeast China, being often stressed severely by pathogenic diseases. In this study, topsoil of a continuously cropped ginseng farm was amended at 20 t ha-1 respectively with manure biochar (PB), wood biochar (WB) and maize residue biochar (MB) in comparison to conventional manure compost (MC). Post-amendment changes in edaphic properties of bulk topsoil and the rhizosphere, in root growth and quality and in disease incidence were examined with field observations and physicochemical, molecular and biochemical assays. Three years following amendment, increases over MC in root biomass was parallel to the overall fertility improvement, being greater with MB and WB than with PB. Differently, survival rate of ginseng plants increased insignificantly with PB but significantly with WB (14%) and MB (21%) while ginseng root quality unchanged with WB but improved with PB (32%) and MB (56%). For the rhizosphere at harvest following three years growing, total content of phenolic acids from root exudate decreased by 56%, 35% and 45% with PB, WB and MB respectively over MC. For rhizosphere microbiome, total fungal and bacterial abundance was both unchanged under WB but significantly increased under MB (by 200% and 38%), respectively over MC. At phyla level, abundances of arbuscular mycorrhizal and Bryobacter as potentially beneficial microbes was elevated while those of Fusarium and Ilyonectria as potentially pathogenic microbes reduced, with WB and MB over MC. Moreover, rhizosphere fungal network complexity was enhanced insignificantly under PB but significantly under WB moderately and MB greatly, over MC. Overall, maize biochar exerted great impact rather on rhizosphere microbial community composition and networking of functional groups, particularly of fungi, and thus plant defense than on soil fertility and root growth.
Nordic socio-recreational ecosystem services in a hydropeaked river system
Authors: Virk Zeeshan
Published: February 2023

Zeeshan Tahir Virka, Faisal bin Ashrafa,b, Ali Torabi Haghighia, Bjorn Klovea, Seppo Hellstenc, Hannu Marttilaaa University of Oulu, Faculty of Technology, Water, Energy, Environmental engineering Research Unitb Stockholm Environment Institute (SEI)c Finnish Environment Institute (SYKE)   Fluctuating energy prices in the Nordic region call for short-term river flow regulation at hydropower plants (HPPs). This short-term regulation leads to Hydropeaking – the pulsating water flow downstream of an HPP. Hydropeaking is detrimental to the overall health of the river, impacting all riverine and riparian ecosystem services. One of the major ecosystem services affected by hydropeaking in Nordic rivers is the socio–recreational ecosystem service (SRES), which holds significant value for Nordic culture and human wellbeing. We examine how SRES are affected by hourly hydropeaking events in a large Nordic River reach. Employing two indicators based on normalized daily maximum flow difference and sub-daily flow ramping we estimated annual and seasonal trends of hydropeaking in the studied reach of the Kemijoki River system. The study reach was found to be under “High Pressure” peaking class in all seasons. For SRES impact assessment, we applied a novel methodological approach to multiple layers of high-resolution spatio-temporal data. An overlay analysis of inundation maps derived from 2D-hydrodynamic modeling and a customized land classification map based on a machine learning algorithm resulted in identification of SRES areas under influence of sub-daily hydropeaking within the study reach. The degree of impact on SRES corresponded to seasonal variations of sub-daily hydropeaking where the highest impact was observed in the summer season The most affected recreational land uses were the shore and litorine areas. Furthermore, as intraday flow ramping results in peaking waves downstream of the HPP, our results show that most part of the river channel becomes hydraulically unsafe during hydropeaking events, especially in summer, which is popular in the context of Nordic culture and tourism. Consequently, hydropeaking can seriously impact the social, and recreational services offered by Nordic rivers; therefore, regulation practices at the HPPs should also consider SPES aspects.  We recommend further research to evaluate these services so that tradeoffs between energy production at HPPs and ecosystem services of rivers can be balanced.
Building Integral Gridded Carbon Emission Disaggregating Model (BIGCarbonEDM): Near real-time community-level CO2 emission evaluations for twelve cities in Egypt, South Africa, and Turkey
Authors: Zhou Chuanlong , de Castelbajac Mathieu , Zhu Biqing , Huo Da , Liu Zhu , Benoit Antoine , Deuskar Chandan , Mesner Craig , Akani-Guéry Julian , Boucher Margaux , Ciais Philippe
Published: February 2023

Cities generate the majority of CO2 emissions, the largest climate change contributor. Near real-time CO2 emission monitoring and modeling at relatively high resolutions are beneficial to fill the knowledge gaps for the spatial and temporal emission patterns in different regions, and to provide the public and the policymakers with accurate and timely information on major emission sources and emission amounts for better public awareness and decision making. On the other hand, there are even larger knowledge and information shortage in Global South counties for the city-/community- level CO2 emissions due to the lack of well-monitored official data with high latency and low transparency.Data-driven models with big data embedded can be one of the most robust and efficient approaches for addressing those challenges in regions without well-documented data. Therefore, we developed the Building Integral Gridded Carbon Emission Disaggregating Model (BIGCarbonEDM) that disaggregates Scope 1&2 CO2 emissions to community-level (with a resolution at 500 meters) using machine learning models trained with building- to regional-level features. Multiple open datasets were used as model inputs, 1) building-level datasets: Microsoft Building Footprints, OpenStreetMap, and OpenStreetMap Building, 2) regional-level datasets: Global Human Settlement, World Settlement Footprint, VIIRS Nightlights, Local Climate Zone, Copernicus Digital Elevation, and land surface temperature, 3) economical and census datasets were collected from the national statistical report and world bank surveys, and 4）city-level near real-time CO2 emission: Carbon Monitor City (https://cities.carbonmonitor.org/), one of our previous projects.BIGCarbonEDM for the first time proposed the approach for capturing the emission patterns for the community level based on building-level and regional-level features and provides the near real-time CO2 emission for twelve major cities in Egypt, South Africa, and Turkey. The cities are Adana, Trabzon, Ordu, and Manisa for Turkey; Cairo, Alexandria, Luxor, and Sheikh Zayed for Egypt; and Johannesburg, Tshwane, Ekurhuleni, and eThekwini for South Africa. BIGCarbonEDM was designed as a modular platform including modules for data collection, data fusion, spatial and temporal emission feature learning, emission estimation model, and data visualization. BIGCarbonEDM modules can be updated and modified separately, which simplifies the improvements and extensions of the final delivered dataset, also all the individual modules can be used by the research community for other relevant research.
New GSRM global warming simulations and active sensors reveal robust changes of tropical convergence zones in cloud ice space
Authors: Bolot Maximilien , Harris Lucas , Cheng Kai-Yuan , Blossey Peter , Bretherton Christopher , Clark Spencer , Kaltenbaugh Alex , Merlis Timothy , Zhou Linjiong , Fueglistaler Stephan
Published: February 2023

Change of the intertropical convergence zone (ITCZ) with global warming has important consequences for the regulation of the tropical climate and for future precipitation projections. Most of the volume of the ITCZ is filled with ice associated with convective anvils, which opens the perspective of using the response of ice clouds to study changes of the tropical convergence zones with global warming. Past studies have shown a decrease of tropical high-cloud fraction with surface warming, whereby the response of anvil clouds is used to interpret the response of ice clouds as a whole. However, tropical clouds organize over a very wide range of scales, meaning that the response of ice clouds is more complex. In particular, precipitating deep convection may represent a small volume of total cloudiness, but it concentrates most of the ascending motion in the tropics and is therefore of crucial importance for the dynamics. Here we show how the high resolution in next generation convection-resolving climate models and in observations can be leveraged to directly measure the response of precipitating deep convection with surface warming in the ice signal. For this purpose, we use the first year-long simulations of global warming ever performed with a Global Storm Resolving Model (GSRM) at 3 km resolution. These simulations use the eXperimental System for High-resolution prediction on Earth-to-Local Domains (X-SHiELD), developed at the Geophysical Fluid Dynamics Laboratory (GFDL). By tracking the response of tropical clouds to surface warming from the response of ice water path (IWP), the vertical integral of ice mixing ratio, we show that the response of precipitating deep convection can be identified at high resolution and that this response, marked by an increase in frequency of very deep convective cores and a decrease in frequency of more moderate convection, is robust in model and active sensor observations. We discuss this result and show how it promotes a simple view of the changes of tropical convergence zones in ice-based coordinates.
The stratosphere–troposphere exchange process during typhoon Molave (2020)
Authors: Chang Shujie , Huang Dong
Published: February 2023

Typhoon is a significant source of deep convection which plays an important role in stratosphere–troposphere exchange (STE) in the Northwest Pacific Ocean. In this study, Typhoon Molave (2020) was simulated by using the Weather Research and Forecasting model (WRF) to examine the STE process and its detailed characteristics compared with the results from ERA5. The geopotential heights and wind field indicate existence of gravity waves (GWs) which transport large amounts of energy through the atmosphere. GWs also allow airmass exchanges between stratosphere and troposphere. A joint analysis of driving field reveals strong linkage between GWs and ozone variations over the region. A significant increasing response of the upper troposphere and lower stratosphere (UTLS) ozone to the gravity wave in areas near the typhoon path. The GW activity caused by typhoon Molave leads to turbulent flow, the mixing of momentum and air mass.
Flood Frequency Analysis in an ephemeral river in Spain: inference from instrumental and historical data
Authors: Viglione Alberto , Sánchez-García Carlos , Schulte Lothar
Published: February 2023

The aim of this study is to evaluate the probability of flood discharges for the Almanzora River (SE Iberian Peninsula) which has a short instrumental series but information on historical events. The maximum peak discharge of the instrumental records that affected the Almanzora River occurred in 1973 and was over 5.000 m3s-1. This extreme event can be considered the most important of the 20th century, but not of history. The main questions we aim to answer are: what is the 100-yr flood for the Almanzora River if we ignore or account for historical events? And, what is the return period of the extreme 1973 flood in the area? We reconstruct the flow rates of the maximum historical floods using the descriptions retrieved from four historical archives within the Almanzora catchment since 1500. To perform the frequency analysis, we establish several thresholds: a) we assume that in the period 1500 -- 1850, no other flood exceeded the perception threshold of 3600 m3s-1, apart those reconstructed; b) during the period 1850 -- 1962, no other flood exceeded the perception threshold of 1300 m3s-1, apart those reconstructed; and c) in the instrumental period, 1963 -- 2016, we just consider as exactly known maximum annual discharges higher than 30 m3s-1. Bayesian inference is applied to fit a GEV distribution and calculate the return periods of flood discharges in the Almanzora watershed. The results show that the Q100 is 3560 m3s-1, with 95% credible bounds ranging from 2700 to 5800 m3s-1. There were at least two flood discharges (much) higher than Q100 from 1500 to 1900, in 1580 and in 1879. In both cases, the descriptions from historical sources support this assumption. Also, we estimate the return period of the 1973 flood as 250 years (with 95% credible bounds from 100 to more than 1000 years). Comparing the results using or ignoring historical floods we obtain that when the analysis is done using just instrumental data, the return period is rather underestimated: Q50 is estimated as 661 m3s-1, while with historical data is over 2000 m3s-1. FFA with historical data gives us better knowledge about the possible hazard in the area, and future river management should consider these new results.
Cooling-rate constraints from metapelites across two inverted metamorphic sequences of the Alpine-Himalayan belt; evidence for viscous heating
Authors: Burg Jean-Pierre , Moulas Evangelos
Published: February 2023

Despite the occurrence of high-grade metamorphic rocks next to and along crustal-scale shear zones, the temporal character of their formation and evolution is difficult to extract. We utilize the major-element diffusion in the compositional re-adjustment of garnet from metapelites in two crustal-scale shear zones as a complementary method to extract cooling rates from deforming/reacting rocks. The two thrust zones, the Nestos Thrust Zone (NTZ) in Rhodope, Greece, and the Main Central Thrust (MCT) in Sikkim, Himalaya, exhibit inverted metamorphic zonation. We applied phase equilibria modelling and geothermometry to constrain the peak- and the post-peak-temperature conditions relevant for the cooling-rate estimates. Results are 50–80 ◦C/Myr in the footwalls of both thrust zones, in consistency with published estimates using geochronology methods for MCT. However, results are much less (~0.5–5◦C/Myr) for the base of the MCT hanging wall. The estimated cooling rates are between 300 and 2500 ◦C/Myr for the NTZ hanging wall. The exceedingly fast cooling rates indicate the operation of transient and proximal thermo-mechanical processes consistent with the contribution of thrust related viscous heating during metamorphism. The very slow cooling rate of the MCT hanging wall may reflect a complex thermal history or other overlooked processes. References:Burg, J.-P., Moulas, E., 2022. Cooling-rate constraints from metapelites across two inverted metamorphic sequences of the Alpine-Himalayan belt; evidence for viscous heating. Journal of Structural Geology 156, 104536. https://doi.org/10.1016/j.jsg.2022.10453
Inferring local social cost from renewable zoning decisions. Evidence from Lower Austria's wind power zoning.
Authors: Wehrle Sebastian , Schmidt Johannes
Published: February 2023

Deploying renewable electricity generators comes with significant benefits but can also bring about social costs, for example, through interference with landscapes or the biosphere. We develop a novel methodology for quantifying the local social costs of renewable energy technologies. Through zoning decisions, authorities implicitly value spatial characteristics by trading-off different traits, such as wind resource quality or distance to settlements. We develop a simple theoretical model of renewable zoning and implement a corresponding discrete choice model that allows us to estimate the implied valuation from observed data in high spatial resolution. The wind power zoning in the federal state of Lower Austria, home to Austria's most significant wind resources, serves as our case study. According to our preliminary estimates, local social costs are non-negligible and significantly affect wind turbines' socially optimal spatial distribution. These results can inform optimal capacity choice in power system models and support wind turbine siting. Moreover, spatially highly resolved assessments of social cost are a significant improvement over conventional potential assessments based on binary exclusion criteria.
Global groundwater recharge assessment over the last two decades
Authors: Nazari Sara , Moosdorf Nils
Published: February 2023

Groundwater is the largest global liquid freshwater source and is vital for providing reliable water resources for growing water consumption. To meet an increasing freshwater demand, the groundwater resources have been excessively exploited, which can cause groundwater depletion and its further consequences, such as land subsidence. Groundwater recharge is a major factor for the sustainable management of groundwater abstraction. One of the most uncertain parts of our knowledge of the global scale hydrological cycle is global groundwater recharge. Yet, measuring groundwater recharge requires detailed knowledge of environmental parameters and is observation-intensive. Therefore, we developed a global groundwater recharge model to analyze global groundwater recharge and estimate its spatial and temporal distribution.The model is a global hydrology grid-based concept implemented in python with a spatial resolution of 0.1°×0.1° and daily temporal resolution. The model comprises three soil layers: topsoil (root zone), subsoil, and aquifer. It simulates the exchange between topsoil and atmosphere performed by meteorological variables, as well as surface runoff, topsoil recharge, soil layers water volume, subsoil recharge, capillary rise from the subsoil to the topsoil, and groundwater recharge. Meteorological and soil properties data from various sources such as ERA5, IMERG, and SoilGrid250m were gathered to build the model and simulate fluxes. The groundwater recharge model applies the water balance budget concept on each soil layer to simulate the daily cell average fluxes values.With the implementation of the global groundwater recharge model from 2001 to 2020, each global basin’s groundwater recharge was calculated. It is estimated that the global average groundwater recharge is 150 mm a-1 varying from zero to 1260 mm a-1. Moreover, a linear regression was applied for the decades 2001-2010 and 2011-2020 to evaluate how recharge has changed. An increasing trend in groundwater recharge was identified found in 68% of the world’s basins in the period 2001 to 2010. For the period from 2011 to 2020, this percentage has decreased to 48%. Basins with declining recharge show the opposite trend, comprising 32% of the basins in the first period and 52% in the second.Global groundwater resources status and the possibility of groundwater shortage can be discovered by applying global groundwater recharge model results. An increasing number of river basins show a decreasing trend of groundwater recharge. These outputs provide insight into uneven global groundwater recharge spatial and temporal distributions and indicate that the groundwater recharge decline in recent years threatens more basins. In addition, the results can be used to identify the regions where groundwater resources are or will be at risk of unsustainability. 
Institutional impacts on the evolution of the Yellow River, China: a perspective from socio-hydrological modelling
Authors: Song Shuang , Wang Shuai , Fu Bojie
Published: February 2023

For governing river basin systems, social-ecological systems (SES) structures can be reshaped by institutions, such as policies, laws, and norms. Effective (“matched” or “fit”) institutions operate at appropriate spatial, temporal, and functional scales to manage and balance different relationships and interactions between human and water systems, supporting (but not guaranteeing) the sustainability of SES. To better understand how water governance institutions match/mismatch their social-ecological context, we take the Yellow River Basin (YRB), China, as an example to dive into causal links between institutional changes and outcomes. An agent-based model was developed around the Yellow River's most far-reaching water quota institution during the past half century, considering how factors such as human behaviour and environmental change have combined with the institutional shifts to lead to changes in the Yellow River's water use. Our results show regional differences in the impact of the system, with some areas tending to ignore the constraints of the quota system when other provinces embarked on a water-saving transition. Our model demonstrates the dramatic impact of institutional change on socio-hydrological processes and has guidness for the sustainable use of water resources at a time when non-engineered measures of water governance are becoming increasingly common.
Interplay between seismic and aseismic deformation near the tip of a creeping segment: Insights from the northern Jordan Valley segment of the Dead Sea Fault
Authors: Hamiel Yariv , Piatibratova Oksana
Published: February 2023

Transient aseismic deformation is observed using dense geodetic measurements across the northern Jordan Valley Fault segment of the Dead Sea Fault. The fault was creeping until 2013 at a rate of 2.7±0.4 mm/yr. It stopped creeping between 2013 and 2018 and then started creeping again at a similar rate. These transitions between the creep and locked modes of deformation correlate well with the 2013 and 2018 seismic sequences that occurred near the tip of the northern Jordan Valley creeping segment. The creep caused the accumulation of Coulomb stresses near the fault tip, which promoted earthquake nucleation in this region. The 2013 seismic sequence was probably too small to release these stresses, and they were released during the 2018 seismic sequence, which allowed the fault to creep again. We suggest that seismic activity will continue to occur near the tip of this creeping segment.
Quantifying the impact of storm surges on mineral accretion rates of coastal marshes
Authors: Cortese Luca , Zhang Xiaohe , Simard Marc , Fagherazzi Sergio
Published: February 2023

Coastal marshes represent a highly valuable ecosystem that provides a wide array of ecosystem services. Unfortunately, marshes survival might be compromised by sea level rise, limited sediment supply, and subsidence. Storm surges represent a fundamental source of sediment for starving marshes because of their ability to resuspend bottom material in channels and tidal flats and transport it to the marsh surface. However, their intermittent nature makes the quantification of their effect not trivial. In this study, we selected 11 storm surges with different intensity in Terrebonne Bay, Louisiana, USA and simulated them with the Delft3D-FLOW model coupled with the Simulating Waves Nearshore (SWAN) module. Simulations revealed that the deposition on the marsh platform is correlated with storm intensity and duration. However, when the storm return period is considered, the surge with 1.7 years return period was found to have the highest geomorphological work. This indicates that the most impactful storms are those that balance intensity with frequency. We introduce a new approach to derive long-term vertical inorganic accretion rates based on simulations of real storm surges. We evaluated every possible combination of 11 storms and selected the one that is most closely related to in situ field measurements. Using a linear model, we derived a spatially distributed inorganic accretion rates with values consistent to field measurements. This method has the advantage of considering real scenarios and can be applied in any marsh-bay system. Overall, this study stresses out the central role storm surges have into feeding sediment starving coastal marshes.
Cropland productivity evaluation based on earth observation and direct measurements, a 100m resolution country assessment
Authors: Csikós Nándor , Szabó Brigitta , Hermann Tamás , Laborczi Annamária , Matus Judit , Pásztor László , Szatmári Gábor , Takács Katalin , Tóth Gergely
Published: February 2023

A methodology of quantitative assessment of soil biomass productivity with 100 m spatial resolution on a country coverage is presented. The traditional land evaluation approach - where crop yield is the dependent variable - was followed using measured yield and net primary productivity data derived from satellite images, together with digital soil and climate maps. Further to characterization of soil biomass productivity based on measured data, the weight of soil properties in productivity was also quantified, thus providing an information basis to design sustainable land management practices. To produce these results, we used the Random Forest method for our calculations. The study considers high-input agriculture, which is predominant in the country.  Biomass productivity indices for major crops (wheat, maize and sunflower) as well as general productivity indices were computed for the whole agricultural area of Hungary. The assessment can be repeated for monitoring purposes to support general monitoring goals as well as for reporting in relation to the Sustainable Development Goals of the United Nations. Nevertheless, based on the findings we also propose a method that enables the periodical update of the evaluation, that can also be used as monitoring biomass productivity in the context of climate change, land degradation and the advancement of cultivation technology.
Analysis of the Energetic Storm Particle events of 6-7 September 2017
Authors: Chiappetta Federica , Laurenza Monica , Lepreti Fabio , Benella Simone , Consolini Giuseppe
Published: February 2023

Most of the energetic particles observed in the heliosphere are accelerated from a few keV up to MeV by shock fronts which are associated with the transit of coronal mass ejections (CMEs). The study of energetic storm particle events (ESP) can be very helpful for the investigation of the acceleration processes of particles at the shocks. We considered two ESP events occurring 6-7 September, 2017. The data used to study kinetic energy spectra are proton ﬂux enhancements provided by WIND and ACE spacecraft that are both at the Lagrangian point L1, close to 1 AU along the Sun-Earth direction. The energy ranges are from 70 keV to 70 MeV and from 40 keV to 4.8 MeV, respectively. In order to broaden the range of the analyzed energies, we combine these data with the proton fluxes from SoHO spacecraft, also located at L1, which detects particles with energies from 1.3 MeV to 130 MeV. We used the Weibull functional form, the double power law and the Ellison-Ramaty form to fit the observed spectra. The implications of the obtained results for particle acceleration are discussed, taking also into account the properties of the shocks and of the magnetic turbulence in their surroundings.“This research has been carried out in the framework of the CAESAR project, supported by the Italian Space Agency and the National Institute of Astrophysics through the ASI-INAF n. 2020-35-HH.0 agreement for the development of the ASPIS prototype of scientific data centre for Space Weather.”
First noble gases measurements in lherzolites from Mt Vulture volcano: new constraints on the mantle below Italy
Authors: Italiano Laura , Caracausi Antonio , Carnevale Gabriele , Paternoster Michele , Rotolo Silvio G.
Published: February 2023

Mount Vulture is a stratovolcano (age 0.75-0.14 Myr) located in southern Italy, which despite being at the same latitude of Vesuvius and Phlegreian Fields, has several peculiarities about its setting and erupted magma composition. Indeed, if compared to other Italian Quaternary volcanoes, it is the only one located east of the Apennine Front, about 100 km off the axis of the Campanian Magmatic Province (Peccerillo et al., 2017). Furthermore, although being a quiescent volcano (last eruption dated 0.14 Myr), previous studies (e.g., Caracausi et al., 2015, Bragagni et al., 2022) have shown extremely high CO2 emissions (4.85 × 108 mol yr-1), which are likely related to the carbonatitic volcanism of its final phase of activity, as well as some petrological aspects in the erupted products pointing to a mantle source metasomatism.Recently, investigations on Vulture mantle xenoliths (Carnervale et al., 2022) revealed CO2-rich fluid inclusions (FIs) that indicate a primary depth of bubbles entrapment in olivine and pyroxene phenocrysts coinciding with the regional crust-mantle boundary (27-30km).This research focuses for the first-time noble gases isotopes (He, Ne, Ar) in FIs from lherzolite enclaves from Mt. Vulture tephra. The He isotopic ratios (as R/Ra; R is the 3He/4He ratio of the sample and Ra the same ratio in air), are between 6.2 and 5.4 ± 0.08. These values are lower than the signatures of the MORB upper mantle (8 ± 1Ra) and overlap the values of the Sub Continental Lithospheric Mantle (SCLM, 6.1 ± 0.9Ra). The Ne isotopic signatures (20Ne/22Ne and 21Ne/22Ne) are in the field of the MORB values.The He-Ne-Ar systematics is consistent with a SCLM source feeding the magmatism of the Vulture volcano. However, considering the noble gases He-Ne-Ar, in Vulture xenolites this mantle source has affinities with that feeding the volcanic activities of Mt. Etna (Nakai et al., 1997; Correale et al., 2014). This inference bears some evidence about the similitudes of the mantle below these two volcanic systems that is affected by mantle metasomatism, which is likely also responsible for the large CO2 fluxes and the carbonatitic magmatism (Bragagni et al., 2022). New measurements of the noble gases in free gases from the two volcanoes together with a detailed comparison between the geochemistry and petrography of the Vulture and Etna most primitive products will provide new constraints on the mantle typology below the two volcanoes and its relationship with the geodynamical evolution of the central Mediterranean.References Bragagni et al., 2021, GeologyCarnevale et al. (2022). Geophys. Res. Lett.Caracausi et al. (2015). Earth Planet. Sci Lett.Correale et al., 2014. LithosNakai et al., (1997). Earth Planet. Sci Lett.Peccerillo, A. (2017). Advances in Volcanology. Springer, Cham.
Detection and characterization of the onset and cessation dates of the dry season in Western Equatorial Africa based on solar radiation
Authors: Ouhechou Amine , Philippon Nathalie , Morel Béatrice
Published: February 2023

Western Equatorial Africa (WEA) is characterized by a long and cloudy dry season extending from June to September. So far, no study has investigated the intra-seasonal characteristics of this dry season especially its onset and cessation dates. In our study, the onset and cessation dates are determined over the 38-year period 1983–2020, using daily surface solar radiation (SSR) data from CMSAF SARAH-2. The maximum and minimum values of the cumulative anomalies of a regional index, for each year, are used to extract the onset and cessation dates. The mean onset date of the dry season in the region is May 17, the mean cessation date is October 3. We obtain very distinct anomaly patterns of SSR but also of low-level clouds and precipitation before/after the onset/cessation dates. The onset and cessation dates show strong year-to-year variability but no significant trend is detected over the 4 decades studied. Lastly, the cumulative anomalies for each year are also used to classify the dry seasons according to the SSR intra-seasonal evolution. Three types of years are obtained which are associated to different patterns of SST anomalies in the tropics.
Process-Based Hydrologic and Hydraulic Modelling for Floods in Brahmaputra
Authors: Samuel Walter , Vuruputur Venugopal , Chakrabarti Ramananda
Published: February 2023

Floods are known to cause extensive damage to property and life, which makes it necessary to determine the plausible magnitude and frequency of these hydrologic extremes. In this study, we use a combined hydrologic and hydraulic modelling approach to study the flood characteristics of Brahmaputra - a large transboundary river (580,000 km2) associated with complex topography, geomorphology, and a dense network of tributaries. A semi-distributed process-based model HEC-HMS, (forced with different precipitation datasets, -(APHRODITE, GLDAS, IMD and TRMM) is used to simulate an ensemble of its historical streamflow at a daily timescale. These calibrated and validated flows are used in conjunction with a network of level gauge stations (within Arunachal Pradesh & Assam in India) to quantify and improve flood mapping with the help of a two-dimensional hydraulic model HEC-RAS. The historical flood extents (2015 to 2022) obtained using the hydrologic & hydraulic modelling approach is further validated with the help of satellite earth observation data products. Such a multi-pronged, ensemble-based modelling strategy has the potential to create a more informed flood risk management system, in terms of providing better likelihood and uncertainty estimates, in the lower reaches of Brahmaputra often prone to prolonged inundation.
Space and Time Characteristics of Flash Drought Over the Central Europe
Authors: Rahim Akif , Markonis Yannis , Ruth Blöcher Johanna
Published: February 2023

Flash drought is a unique natural hazard due to its rapid rate of intensification with potentially detrimental effects on agriculture production. So far few work has been done to investigate the space and time behavior of flash droughts across Central Europe. In this study, we examine the space and time characteristics (Frequency, Rate of intensification, Severity, and Extent) of flash drought events in Central Europe between 1970 and 2020. The weekly averaged top layer (1-10cm) soil moisture (SM) data set of the Global Land Data Assimilation System (GLDAS) has been used as an indicator for identifying flash drought events. Here, we adopted a new definition for flash droughts by considering the intensity, duration, and persistence of flash drought. The results of this study reveal that the occurrence of flash droughts over Central Europe increased rapidly in the last two decades. The intensification rate and severity of flash drought show positive correlation. Moreover, the areal extent of flash drought events increased since 1970 and their centroid shifted towards the southern part of Central Europe. This study provides a better understanding of flash drought process and its dynamics over Central Europe.