bluuebunny/crossref_metadata_2025 huggingface dataset:
Significantly reduced extreme streamflow and sediment load in the Yellow River Basin: Impacts of climate change and human activities
Authors: Yin Shihua , Gao Guangyao , Fu Bojie
Published: February 2023

Over the past decades, the increasing frequency and intensity of extreme events due to climate change and anthropogenic climate change have greatly increased the threat to the production and livelihood of people along the riverbank. Hence, it is crucial to analyze the extreme variations of streamflow and sediment load observed in large rivers to better predict future changes in the world's water resources and hydrological extremes. In this study, we show the spatiotemporal variations of streamflow extremes and sediment load extremes in the mainstream of the Yellow River based on the daily streamflow and sediment load data from 1956 to 2019 and multiple mathematical and statistical methods. Then, we identify the main factors related to human activities and climate change by establishing quantitative relationships to figure out how these factors altered extreme streamflow and sediment load. Our results reveal that extreme streamflow and sediment load have decreased significantly since the 1950s (p < 0.05) except for the Yellow River source. However, the extreme streamflow increased significantly (p < 0.05) during 2000-2019, likely due to increased precipitation, and the extreme sediment load at most stations tended to stabilize. The contribution of extreme streamflow to the annual streamflow declines remarkably in the middle-upper reaches and increases significantly in the Lower reaches. While the contribution of extreme sediment load to the annual sediment load decreased significantly in the middle-lower reaches. Besides, the occurrence dates of extreme streamflow and sediment load showed an overall trend to disperse from the flood season to the four seasons of a year. We also have evidence that the fundamental cause of extreme water-sediment yield is extreme precipitation. Yet the extremity and hazard of water-sediment extremes are strongly affected by anthropogenic activities. Among them, mainstream dams can artificially change the water-sediment extremes, relationship, and synchronization, while anthropogenic engineering and vegetation measures can reduce the maximum possible peak of water-sediment extremes. Changes in the water-sediment relationships across the basin also confirm that changes in sediment source availability or erosive power dominate sediment reduction in each sub-basin. This study provides a scientific basis for risk management and water resources development and utilization in complex watersheds.
Extreme Tibetan Plateau cooling caused by tropical volcanism
Authors: Liu Fei , Dong Wenjie
Published: February 2023

Extreme cooling during boreal winter in Tibetan Plateau (TP) poses great threats to local environment and people’s live safety, and it has usually been attributed to climate internal varaibility. Here we show that the recent five large tropical volcanic eruptions since 1863  induced an extreme TP cooling up to -0.8 K in the first boreal winter post-eruptions, much larger than the global average terrestrial cooling of -0.3 K. This extreme TP cooling response (-0.79 K)  to tropical eruptions is simulated by the multimodel ensemble mean of the Phase 6 Coupled Model Intercomparison Project when realistic sea surface temperature is specified for the atmospheric models, and it is much larger than the direct aerosol cooling (-0.36 K) simulated by the historical runs. The positive North Atlantic Oscillation during the post-eruption winter plays the key role in amplifing the TP cooling through atmospheric teleconnection, which overwhelms the warming response associated the frequently occurring El Niños. Results from this study put into perspective the potential volcanic contribution in certain extreme Tibetan Plateau cooling events. 
Improved Understanding of the East Asian Monsoon Rainbands and Dynamics Via Lagrangian Moisture Tracking and Atmospheric Rivers Analysis
Authors: Lu Mengqian , Cheng Tat Fan , Dai Lun
Published: February 2023

In East Asia, summer monsoon rainbands usually stretch for thousands of kilometers in the east-west direction and are capable of producing heavy rainfall intensity of 20-40 mm day-1 on average, rendering them the culprit of many devastating historical floods. Despite the previous endeavor to understand their formation dynamics and hazards, the atmospheric water cycle of these rainband systems remains surprisingly poorly understood. In this study, we leverage backward moisture tracking to demystify the dominant moisture pathways and sources that feed the East Asian rain belt events during the warm season (April to September) from 1981 to 2018. The simulations were conducted using a semi-Lagrangian dynamical recycling model (DRM) forced by hourly-0.25˚ ERA5 reanalysis. In virtue of an Expectation-Maximization (EM)-based curve clustering, we classify up to 15 moisture pathways along four main corridors reaching the Somali Jet, South Asia, the Bay of Bengal and the Pacific basin. Long-range moisture pathways turn out to dominate high-impact monsoon rainbands, coinciding well with the role of planetary-scale atmospheric rivers in triggering extreme rainfall over East Asia. The result also highlights the importance of terrestrial moisture pathways and sources in supplying rain belts. Back-tracing the moisture pathways and atmospheric rivers unravels interesting couplings of pre-existing weather systems. The terrestrial moisture pathways over South Asia turn out to link to circumglobal wave trains at the upper levels up to a two-week lead time. The findings here bridge the knowledge gap in the regional hydrological cycle of the disastrous East Asian rain belts. The pre-existing weather systems uncovered by tracking the moisture and atmospheric rivers also provide potential predictability of heavy precipitation in East Asia.
ENSO phase space dynamics with an improved estimate of the thermocline depth
Authors: Dommenget Dietmar , Priya Priyamvada
Published: February 2023

The recharge oscillator model of the El Niño Southern Oscillation (ENSO) describes the ENSO dynamics as an interaction and oscillation between the eastern tropical Pacific sea surface temperatures (T) and subsurface heat content (thermocline depth; h), describing a cycle of ENSO phases. h is often approximated on the basis of the depth of the 20oC isotherm (Z20). In this study we will address how the estimation of h affects the representation of ENSO dynamics. We will compare the ENSO phase space with h estimated based on Z20 and based on the maximum gradient in the temperature profile (Zmxg). The results illustrate that the ENSO phase space is much closer to the idealised recharge oscillator model if based on Zmxg than if based on Z20. Using linear and non-linear recharge oscillator models fitted to the observed data illustrates that the Z20 estimate leads to artificial phase dependent structures in the ENSO phase space, which result from an in-phase correlation between h and T. Based on the Zmxg estimate the ENSO phase space diagram show very clear non-linear aspects in growth rates and phase speeds. Based on this estimate we can describe the ENSO cycle dynamics as a non-linear cycle that grows during the recharge and El Nino state, and decays during the La Nina states. The most extreme ENSO states are during the El Nino and discharge states, while the La Nina and recharge states do not have extreme states. It further has faster phase speeds after the El Nino state and slower phase speeds during and after the La Nina states. The analysis suggests that the ENSO phase speed is significantly positive in all phases, suggesting that ENSO is indeed a cycle. However, the phase speeds are closest to zero during and after the La Nina state, indicating that the ENSO cycle is most likely to stall in these states.
Influences of different orbit interpolation methods on substitution accuracy of rational polynomial coefficient model for multi-mode images from Gaofen-3 Satellite
Authors: Xin Liu , Mingjun Deng , Yin Yang , Yan Zhou , Zhengpeng Zhang
Published: February 2023

Determining the satellite orbit vector is necessary when constructing the geometric positioning model for a Synthetic Aperture Radar image from the Gaofen-3 satellite (GF-3), as it greatly impacts the geometric positioning accuracy. Therefore, it is vital to obtain accurate orbit vector data regarding the satellite imaging time. Here, GF-3’s orbit was interpolated using the Lagrange interpolation, Chebyshev polynomial, and ordinary polynomial methods, with each method’s influence on the substitution accuracy of the Rational Polynomial Coefficient (RPC) model being analyzed for GF-3’s various imaging modes. The results show that based on Lagrange interpolation orbit, the accuracy of RPC substitution is greatly affected by the length of the orbit, and the stability of RPC substitution accuracy is limited by the position of the interpolation orbit segment. In general, this method shows low RPC substitution accuracy and large fluctuations. The Chebyshev polynomial method and the ordinary polynomial method are less affected by the orbital length and can obtain high substitution accuracy. The RPC substitution accuracy of the two methods was higher than 0.08 % and 0.02 %, respectively. In addition, the results of RPC substitution accuracy are more stable and reliable when ordinary polynomial interpolation orbit is used. 
Scalar wave equation modeling with dispersion relation based on finite difference method
Authors: Mounika Vanga , Ojha Maheswar
Published: February 2023

The finite-difference method(FDM) is widely used in the numerical modeling of wave equations. Conventional FDM stencils for spatial derivatives are usually designed in the space domain, which creates difficulty in satisfying the dispersion relations exactly while solving the wave equations. We use an automated and optimized FDM using a genetic algorithm to optimally compute second-order spatial derivatives. In our method, the explicit finite-difference stencils are calculated using the genetic algorithm to minimize the dispersion (phase velocity) for all wavenumbers without using any specific window function. The amplitudes of the pseudo-spectral window are optimized by making the phase velocity close to the analytical solution at each wavenumber, where the stability is close to that of the conventional FDM. Although finite difference coefficients in this method depend on velocity, grid spacing and time step, less dispersive solutions can be achieved by computing suitable finite-difference coefficients for varying cases. We compare our results with the solutions of an existing pseudo-spectral method (with Kaiser window function), conventional FDM, joint time-space optimization method, and the least square method. The normalized phase velocity and the absolute error of our method show very promising results.
Seasonal, inter-annual and long-term changes in the middle atmospheric Carbon Monoxide over the tropics
Authors: Nath Oindrila
Published: February 2023

Seasonal, annual and long-term changes of carbon monoxide (CO) are investigated in the tropical (30° N ̶ 30° S) middle atmosphere (20 ̶ 80 km) for the period 2005 ̶ 2021. CO shows a semi-annual oscillation in the higher heights of both stratosphere and mesosphere. The CO response to the solar cycle increases with altitude (>2 ppmv/100 SFU) in the mesosphere. CO response to Quasi Biennial Oscillation (QBO) and El Niño and Southern Oscillation (ENSO) is negligible in stratosphere, however, that to ENSO is significantly negative in mesosphere. In the altitude range 60 ̶ 70 km, we find a positive trend (0.03 ppmv/dec) at 64 km. Furthermore, the CO trend is positive in mesosphere (70 ̶ 80 km), with a peak at 75 km (0.19 ppmv/dec). The observed changes in middle atmospheric CO in the tropics are well reproduced by the Whole Atmospheric Chemical Climate Model (WACCM). Therefore, this study provides new insights into the long-term changes in the tropical middle atmospheric CO and its connection to dynamics of the region.
The spatiotemporal distributions of global paleo-Köppen climate belts during the Mesozoic-Cenozoic
Authors: Yu Chenmin , Cao Shuo , Zhang Laiming , Wang Chengshan
Published: February 2023

Climate paleogeography refers to adding climatic information to traditional paleogeographic maps by using paleoclimate classifications. Here we present a series of global paleo-Köppen climate maps from 250 Ma to 0 Ma (per 10 million years) with a high resolution based on the quantitative paleoclimate data simulated by Li et al. (2022). Based on these maps, we evaluate the areal and latitudinal evolutions of paleo-Köppen climate belts during the Mesozoic-Cenozoic. Based on an updated classification that divides “Hothouse”, “Greenhouse”, and “Icehouse” states by global average temperature, we evaluate the areal, latitudinal, and altitudinal characteristics of the paleo-Köppen climate belts for different climate states.
The impact of solar flare induced ionospheric disturbances on 27-day signatures in the T/I-system: preliminary results
Authors: Schmölter Erik , Dühnen Hanna , Berdermann Jens
Published: February 2023

Changes in solar activity are dominant drivers of long- and short-term variations in the upper atmosphere, which can affect each other through complex processes. Regular signatures in the ionosphere are caused, for example, by the 27-day solar rotation period and may be described with a delay of 1 to 2 days in addition to the respective amplitude. Such signatures and the associated delayed response of the ionosphere are influenced by several long-term variations (e.g., seasonal variations or 11-year solar cycle) as described in preceding studies. Here, we present the influence of solar flares on the ionospheric 27-day signatures providing a first insight into the interactions with short-term perturbations. Therefore, we present the response of different thermospheric and ionospheric parameters during X-class solar flare influenced 27-day signatures. We show in particular how the occurrence of solar flares can change accumulation processes and the resulting delay. The observed changes are especially dependent on the phase of the 27-day period in which the solar flares occur. The longest delays are observed for solar flares occurring during the ascending phase of the 27-day solar rotation period. The results are discussed in respect to preceding studies. Finally, we provide an outlook on a possible extension of the analysis by including M-class solar flares as well as additional space weather data sets and modeling results.
Numerical modelling of the volcanic plume dispersion from La Soufrière de Guadeloupe
Authors: Rave Bonilla Yuly Paola , Jessop David , Moune Séverine
Published: February 2023

Passive volcanic degassing often occurs at active but not actively erupting volcanoes. Gases are emitted by fumaroles and through diffuse soil degassing. This results in the emission of toxic gases such as H2S at quasi-steady rates over long periods of time (months to years). Whilst less apparent than gas emissions during more vigorous and violent paroxysms, the long duration of emission and the fact that such gases are dispersed at low altitude (i.e. along the flanks of the volcano, often at human height) means that even the typically low concentrations (e.g. tens of ppb H2S) pose a significant hazard to human health in nearby habitations.La Soufrière de Guadeloupe has been undergoing an unrest phase since 1992 and it has one of the highest gas emission rates of any volcano in the Lesser Antilles. Gas emissions here are principally from three fumarolic sites at the summit though the typically high winds and low gas temperatures result in a laterally dispersed plume within a few metres of the ground. In this study, gas dispersion from the volcano over the period 2016–2021 was modelled using a numerical code that takes into account wind direction and strength, atmospheric stability, local topography and gas flux measurements; we used information from local meteorological stations, ECMWF Climate Reanalysis data and the gas flux dataset acquired by MultiGas measurements during the mentioned period.  We ran c.100 individual simulations of the most frequently observed wind and gas flux conditions using a Monte-Carlo scheme. From the ensemble of results, we calculated the mean (i.e. most probable gas concentration values at any given location) and found that the most exposed zones are the hamlet of Matouba and the upper parts of St. Claude. We also simulated particular dates with strong H2S odours reported by local inhabitants via online surveys and we compared the model results with the Gwad’air agency’s air quality station located at St Claude, the closest town to the volcano. This allowed us to establish the prevalence of gases coming from La Soufrière in nearby cities and the accuracy of our models. The resulting maps of the areas potentially long-term (>8 years) exposed by gas emissions can be used to evaluate health risks for all people living around the volcano. In these locations, our results suggest that there is a 20% and 5% probability, respectively, for these areas of exceeding H2S guidelines for long-term gas exposure (70 ppb).
Assessment of the impact of mesoscale eddies on the large-scale physical and biogeochemical responses under climate change
Authors: Ruan Xi , Couespel Damien , Levy Marina , Li Jiying , Mak Julian , Wang Yan
Published: February 2023

Earth System Models utilized to predict the ocean physical and biogeochemical responses under anthropogenic climate change do not yet routinely resolve mesoscale eddies due to computational resource constraints, and ocean mesoscale eddies are often parameterized. Mesoscale eddy parameterizations are known to affect the large-scale ocean circulation through impacts on the stratification, leading to for example changes of the nutrient stream, which is known to have large-scale impacts for the nutrient supply. Here we examine numerical ocean models with different representations of the mesoscale eddies and their combined physical and biogeochemical response in a hierarchy of models differing in the horizontal resolution, ranging from a non-eddying model with eddy parameterization, eddy permitting models without and with eddy parameterization, and eddy resolving models that serves as the model truth. In the case of non-eddying models, we find that existing prescriptions can result in a "better" bulk biogeochemical response but for the wrong physical reasons, relative to the model truth. On the other hand, more recent parameterization schemes can improve the physical response in terms of the sensitivity to changes in forcing, but the biogeochemical response is more subtle. It is confirmed here that the biggest change in the biophysical response stems from a model becoming eddy permitting. However, the eddy permitting model without parameterization is found to overshoot and be "too good" relative to the model truth in the biogeochemical response, attributed to the explicit eddies being too weak. Results are presented from a new approach that supplements the action of explicit eddies in eddy permitting model via eddy parameterization, but without adversely damping the explicit eddies. Combined with more recent parameterizaton schemes, the approach can lead to a biogeochemical response that compares very favorably to the model truth, attributed entirely to the improvement in the physical response in the eddy permitting model, so that we are getting the right answer for the right reasons.
Solar activity relations in energetic electron events measured by the MESSENGER mission
Authors: Rodríguez-García Laura , Balmaceda Laura , Gómez-Herrero Raúl , Kouloumvakos Athanasios , Dresing Nina , Lario David , Zouganelis Yannis , Fedeli Annamaria , Espinosa Lara Francisco , Cernuda Ignacio , Ho George , Wimmer-Schweingruber Robert , Rodríguez-Pacheco Javier
Published: February 2023

We perform a statistical study of the relations between the properties of solar energetic electron (SEE) events measured by the MESSENGER mission from 2010 to 2015 and the parameters of the respective parent solar activity phenomena to identify the potential correlations between them. During the time of analysis MESSENGER heliocentric distance varied between 0.31 and 0.47 au.The main conclusion of the study is as follows. For this particular sample of events, with a majority of SEE events being widespread in heliolongitude and displaying relativistic electron intensity enhancements, a shock-related acceleration mechanism might be relevant in the acceleration of near-relativistic electrons. This conclusion is mainly based on three results. (1) The high and significant correlation found between the SEE peak intensities and the shock speed. (2) The ∼4 orders of magnitude in the SEE peak intensities for the same CME-driven shock speed that might be related to the presence of supra-thermal seed population that made local shock acceleration more efficient. (3) The asymmetry to the east of the range of connection angles (CAs) for which the SEE events present higher peak intensities and higher correlations with the solar activity, which might be related to the evolution of the magnetic field connection to the shock front. We note that the CA is defined as the angular distance between the footpoint of the magnetic field connecting to the spacecraft and the longitude of the source region.
Early Indosinian magmatism in the West Qinling orogen and its tectonic implication
Authors: Wang Meng , Pei Xianzhi , Li Zuochen , Li Ruibao , Pei Lei , Chen Youxin , Liu Chengjun , Zhao Shaowei
Published: February 2023

The West Qinling Orogen (WQO), which is bounded by the Qilian Orogenic Belt, Qaidam Block and the Songpan-Ganzi Block, is the western extension of the Qinling Orogenic Belt, and experienced complex tectonic evolution processes, involving the opening, subduction and closure history of the Proto- and Paleo-Tethys Oceans. The WQO features widespread Indosinian magmatic rocks, which are crucial to constrain the tectonic evolution of the WQO. The Indosinian magmatic rocks were formed mainly in two stages, 250 to 240 Ma and 225 to 210 Ma. The Early Indosinian magmatic rocks (250 to 240 Ma) are mainly distributed in the west and middle northern WQO. In comparison, the Late Indosinian magmatic rocks are mainly exposed in the eastern WQO, but also in the western WQO and the Bikou terrane. Controversy has existed for a long time on the petrogenesis and tectonic setting of the Early Indosinian magmatic rocks. We selected four respective plutons, including the Heimahe pluton, the Ren’ai pluton, the Daerzang pluton and the Ganjiagongma pluton. Detailed field investigation, petrology, LA-ICP-MS zircon U-Pb dating, zircon Lu-Hf isotope analyses, whole rock geochemistry and Sr-Nd isotope analyses, and mineral EPMA analyses were conducted for the studied plutons. The studied plutons were emplaced between 246 to 241 Ma according to zircon U-Pb dating results. Based on detailed studies on petrology, geochronology and geochemistry, we emphasis the significance of magma mixing in the petrogenesis of the Early Indosinian granitic rocks. The high Mg# signature of the Early Indosinian granitic rocks were generated by magma mixing between mafic and felsic magmas, but not result of direct fractional crystallization of mafic rocks. The granitic rocks with high Sr/Y values in the WQO, represented by the Ganjiagongma pluton, were not derived from thickened continental crust. No evident continental thickening occurred in the WQO during the Early Indosinian. Combining with regional geological evidence, we propose an alternative tectonic model to explain the evolution history of the WQO during the early Mesozoic. The A’nimaque-Mianlue ocean subducted northward with low angle, then the subducted slab rolled back during the Late Permian to Middle Triassic, and the ocean closured in the Late Triassic. This model can explain the spatial and temporal distribution characteristics of the magmatic rocks and sedimentary rocks, as well as Late Triassic uplift and deformation event in the WQO.
Adjoint-State Surface Wave Tomography for Azimuthally Anisotropic Media: Eikonal Equation-Based Methods and Incorporation of Surface Topography
Authors: Hao Shijie , Tong Ping , Chen Jing
Published: February 2023

Surface waves contain critical information on seismic azimuthal anisotropy, which is directly related to underground geological dynamics. However, despite seismic azimuthal anisotropy, the topographic variation may also contribute to the azimuthal dependence of surface wave speed. To our knowledge, most surface wave traveltime tomography methods ignore the topographic variation in forward modeling. Furthermore, the theoretical propagation path is also calculated in isotropic media with flat surface. Undoubtably, inaccurate forward simulations could introduce artefacts to imaging results.  

To address these problems, we develop a novel surface wave tomography method which tracks the surface wave propagation path in anisotropic media and incorporates the topographic variation. An elliptically anisotropic eikonal equation is used to describe the traveltime field of surface wave propagation, and sensitivity kernels with respect to shear wave velocity and azimuthal anisotropy are derived using the adjoint-state method. This new tomography method is tested and verified in Po Basin and adjacent regions, including the central Alps and northern Apennines.  
Investigate the Optimization of Micro-hydropower in Agricultural Channels in the Water-energy-food Nexus
Authors: Shih Jen-Chieh , Lin Fu-Yuan , Hong Ming-Der , Lin Hong-Ru , Wen Jet-Chau
Published: February 2023

Micro-hydropower is an excellent source of renewable energy. There is no need to build additional DAMs, so it has the advantages of lower setup costs and construction times and reduces greenhouse gas emissions during the generation process. Central and southern Taiwan is mainly developed by agriculture, especially the Zhuoshui River Basin, which has a large watershed area, developed agricultural irrigation system, abundant water source and stable flow, so it is suitable for the installation of micro-hydropower. Its micro-hydropower generation mainly uses the kinetic energy of water to drive the turbine to generate electricity, and the water in the agricultural channel does not disappear with the installation of the turbine.Therefore, this study selected Linnei channel in the Zhuoshui River Basin in central Taiwan as the research site. It is Linnei channel, an agricultural irrigation channel with a stable flow rate, and the first group of micro-hydropower generation was installed in Linnei channel in 2018, and the second groups of micro-hydropower generation were installed in 2020. Therefore, this study measured the water level and flow of the Linnei channel from 2018 to 2022 to analyze the flow changes with or without micro-hydropower generation. Using rice planting evaluate the agricultural economic output value brought by irrigation water. Since 2019, the addition of hydropower generation increased the income brought by hydropower generation. The benefits and costs of each year are compared, and the economic analysis method is used to evaluate whether the installation of hydropower generating units is worth the investment and whether they can get benefits. The results showed that the increase of channel water volume could lead to more rice harvest, but there was no positive correlation between power generation and irrigation water volume. The addition of additional micro-hydropower in 2022 with sufficient irrigation increased net profit margin by only 0.02%, compared to 0.07% in 2019 with less irrigation. It shows that the relationship of the water-energy-food nexus has not yet been optimized, and in the future add the interaction between energy and water to optimize the profit of the system.
Development of Mitigation Device to Wind Risk on Urban Region
Authors: Um Jeong Ah , Lee Sungsu , Kim Byungjo , Shin Seunghun , Woo Jongyeol
Published: February 2023

As urbanization progresses worldwide, the number of high-rise buildings is rapidly increasing, especially in large cities, and the damages from building wind are expected to increase further. In particular, strong winds in urban canyon frequently damage doors, windows and signboards, etc. There also is a risk of building exterior materials scattering due to delamination at the edges of buildings, vortex generation, and gust. Among the damage caused by the building wind, the damage by the exterior material that has been removed due to strong wind can cause not only property damage but also personal damage. Recently, concerns about the damage of building winds in urban areas on pedestrian safety and living environment are increasing, but there is very little consideration in domestic architecture and urban planning procedures. Therefore, it is very essential to reduce the possibility of delamination of exterior materials by strong wind and consequent low pressure. The purpose of this study is to develop mitigation device attached to the edges of the buildings to lower the maximum peak pressure to reduce the potential detachment of building envelope. Using CFD and experimental approach, it was found that developed device can reduce the maximum peak pressure up to 20%.This research was supported by a grant (RS-2022-00155691) of Disaster-Safety Industry Technology Commercialization R&D Program, funded by Ministry of Interior and Safety (MOIS, Korea).
Assessment of Human Health Risks from Arsenic Contamination in Groundwater-Soil-Crop System of a Humid Sub-Tropical Region in India
Authors: Dhamija Sana , Joshi Himanshu
Published: February 2023

Arsenic (As) pollution has become a global concern due to its toxic and carcinogenic nature. Even at relatively low concentrations, arsenic can cause acute and chronic human toxicity. In the current study, samples of groundwater, soil at three depths (top, 50cm, and 150 cm), and grains were collected from a humid sub-tropical region in India encompassing Ballia, Deoria, and Mau districts in the state of Uttar Pradesh. All the samples were analyzed for arsenic employing Inductively Coupled Plasma Mass Spectrometry (ICPMS-MS). 60.3% of groundwater samples exceeded the Bureau of Indian Standards (BIS) permissible limit of 10 μg/l. 40% of soil samples were above the mean background concentration for arsenic in the soil as indicated by the Indian Agricultural Research Centre (IARC), i.e., 5 mg/kg. Further, Human Health Risk Assessment (HHRA) was evaluated in four stages: hazard identification, dose-response assessment, exposure assessment, and risk characterization. HHRA estimates the nature, magnitude, and probability of arsenic impacts in the present and the future. Chronic Daily Intake rate (CDI) was determined to assess the exposure, which depends on the mobility of arsenic in groundwater→soil→crop system. The gradual increase in arsenic contamination in groundwater, mostly used in irrigation, finds its way to the food chain either via drinking or cooking, which is a matter of concern for humans. For risk assessment, Total cancer risk (TCR) and Hazard Index (HI) were computed. Finally, the study estimated the cancerous and non-cancerous risks from arsenic toxicity in groundwater-soil-crop system to human adults and children. The cancerous risk for arsenic contamination was in the order of adults>children due to long-term exposure to arsenic by adults. In contrast, the non-cancerous risks for adults and children exceeded the threshold value of 1 provided by the U.S. Environmental Protection Agency (USEPA), specifying a high health risk rate (children>adults). Apparently, children are more sensitive to chemicals in comparison to the adaptability of adults, and hence, they are most affected. It is envisaged that studies like this, which examine scenarios of elevating probabilities of health risks in children and adults from arsenic-contaminated groundwater, soil, and crops, would enable more rational and decisive actions from the concerned stakeholders for arsenic management in the future.
Integrated modeling of radiation transfer, plant growth, and the movement of soil moisture in the soil–plant–atmosphere continuum (STEMMUS–SCOPE-WOFOST v1.0.0)
Authors: Yu Danyang , Zeng Yijian , Wang Yunfei , Su Bob
Published: February 2023

Accurate estimation of carbon assimilation and allocation plays a significant role in the plant growth and terrestrial ecosystems. The STEMMUS-SCOPE model integrates photosynthesis, fluorescence emission, and transfer of energy, mass, and momentum in the soil–plant–atmosphere continuum system, and has good performances in estimating water, energy, and carbon fluxes. However, the plant growth states (i.e., leaf area index (LAI) and plant height (PH)) are needed as inputs for running the STEMMUS-SCOPE model, and are obtained either from interpolating observations or taking as constants over the time. As a result, the physical interactions are not adequately captured between radiative transfer, plant growth and soil water movements. The objective of this study is to consider the plant growth in STEMMUS-SCOPE model via coupling a crop growth module (i.e., WOFOST module). The coupled STEMMUS-SCOPE-WOFOST model was evaluated with plant functioning measurements. The results indicate that the simulation of LAI and PH is significantly improved and consistent with the dynamic of the water stress and gross primary production (GPP). Besides, the additional generated state variables (i.e., the biomass of root, leaf, stem as well as yield) can also agree well with the observations. Finally, the interactions between the land surface fluxes, soil moisture dynamic and plant growth are all well simulated. The STEMMUS-SCOPE-WOFOST model provides a mechanistic window to link the satellite observation of solar-induced fluorescence to above- and below-ground biomass, land surface fluxes, and root zone soil moisture, in a physically consistent manner.
How does spatiotemporal dynamics of large wood impact its ecosystem services in a meandering river?
Authors: Poledniková Zuzana , Galia Tomáš
Published: February 2023

Large wood is an essential component of the river channel. Channel morphodynamics are impacted, specific habitat for aquatic biota is created, and aesthetic or education function is enhanced by the presence of large wood in the river. The concept of ecosystem services can be applied to describe the functions of large wood. In the case of large wood, there can also be potential risks for human society connected with flooding or bank erosion. We inventoried large wood in 13 active meanders of the Odra (Oder) River, Czechia, and its potential ecosystem services. We surveyed large wood using aerial images (2012 and 2020) and field surveys (2016 and 2020). Based on previous literature research, we assessed each large wood piece separately and decided on the services (3 main categories and 13 subcategories) based on the functions by preselected indicators. Preliminary results show that the functions and provided services depend mainly on the residence time of large wood in the channel and its additional characteristics such as dimensions, type of large wood (e.g., whole tree with preserved crown, present/absent root wad) or its orientation against the flow. We provide a methodological approach of (i) possible assessment of large wood in the river reach to summarize its benefits and risks and (ii) to simplify the understanding of the presence of large wood and its promotion to river practitioners, city planners, and the broader public.
Study on surface layer turbulent and energy exchange in Eastern edge of the Tibetan Plateau
Authors: Li Maoshan , Chang Na , Ma Yaoming
Published: February 2023

Mount Emei is located in the eastern edge of the Tibetan Plateau, on the transition zone between the main body of the Tibetan Plateau and the Sichuan Basin in China. It is not only the necessary place for the eastward movement of the plateau system, but also the place where the southwest vortex begins to develop. Its special geographical location makes it particularly important to understand the turbulence characteristics and surface energy balance of this place. Based on the Platenay Boundary Layer (PBL) tower data, radiation observation data and surface flux data of Emeishan station on the eastern edge of Tibetan Plateau from December 2019 to February 2022, the components of surface equilibrium are estimated by eddy correlation method and Thermal Diffusion Equation and Correction (TDEC) method, the characteristics of surface energy exchange in Emeishan area are analyzed, and the aerodynamic and thermodynamic parameters are estimated. The results show that the annual average value of zero-plane displacement d is 10.45 m, the annual average values of aerodynamic roughness Z0m and aerothermal roughness Z0h are 1.65 m and 9.95 m, respectively, and the annual average values of momentum flux transport coefficient CD and sensible heat flux transport coefficient CH are 1.58×10-2 and 3.79×10-3, respectively. Under the unstable stratification, the dimensionless three-dimensional wind fluctuation variance in Emeishan area can better conform to the 1/3 power law of Monin-Obukhov similarity theory. In the near neutral case, the dimensionless velocity variances in the u, v and w directions are 2.412, 2.181 and 1.125 respectively, and the dimensionless velocity variances in the horizontal direction are greater than those in the vertical direction. The diurnal and seasonal variations of each component of surface balance are more obvious. The dominant position of sensible heat flux and latent heat flux during the day varies with seasons. The latent heat flux is dominant in summer and the sensible heat transport is dominant in winter. The diurnal variation range of surface albedo in Emeishan area shows the characteristics of large in the morning and small in the afternoon, which is an asymmetric "U" shape. Its value is between 0.04-0.08. The surface albedo in summer and autumn is higher than that in Emeishan. The influence of underlying surface on surface reflectance is much greater than other factors such as altitude, longitude and latitude.
Hydrological setting control 137Cs and 90Sr concentration at headwater catchments in the Chornobyl Exclusion Zone
Authors: Igarashi Yasunori , Onda Yuichi , Matsushita Koki , Sato Hikaru , Wakiyama Yoshifumi , Lisovyi Hlib , Laptev Gennady , Samoilov Dmitry , Kirieiev Serhii , Konoplev Alexei
Published: February 2023

Concentration-discharge relationships are widely used to understand the hydrologic processes controlling river water chemistry. We investigated how hydrological processes affect radionuclide concentrations (137Cs and 90Sr) in surface water in the headwater catchment at the Chornobyl exclusion zone in Ukraine. In flat wetland catchment, the depth of saturated soil layer changed little throughout the year, but changes in saturated soil surface area during snowmelt and immediately after rainfall affected water chemistry by changing the opportunities for contact between suface water and the soil surface. On the other hand, slope catchments with little wetlands, the water chemistry in river water is formed by changes in the contribution of "shallow water" and "deep water" due to changes in the water pathways supplied to the river. Dissolved and suspended 137Cs concentrations did not correlate with discharge rate or competitive cations, but the solid/liquid ratio of 137Cs showed a significant negative relationship with water temperature, and further studies are needed in terms of sorption/desorption reactions. 90Sr concentrations in surface water were strongly related to water pathways for each the catchments. The contact between surface water and the soil surface and the change in the contribution of shallow and deep water to stream water could changes 90Sr concentrations in surface water for in wetland and slope catchments, respectively. In this study, we revealed that the radionuclide concentrations in rivers in Chornobyl is strongly affected by the water pathways at headwater catchments.
Machine learning based automated parameter tuning of ICON-A using satellite data
Authors: Bonnet Pauline , Iglesias-Suarez Fernando , Gentine Pierre , Giorgetta Marco , Eyring Veronika
Published: February 2023

Global climate models use parameterizations to represent the effect of subgrid scale processes on the resolved state. Parameterizations in the atmosphere component usually include radiation, convection, cloud microphysics, cloud cover, gravity wave drag, vertical turbulence in the boundary layer and other processes. Parameterizations are semi-empirical functions that include a number of tunable parameters. Because these parameters are loosely constraint with experimental data, a range of values are typically explored by evaluating model runs against observations and/or high resolution runs. Fine tuning a climate model is a complex inverse problem due to the number of tunable parameters and observed climate properties to fit. Moreover, parameterizations are sources of uncertainties for climate projections, thus fine tuning is a crucial step in model development.Traditionally, tuning is a time-consuming task done manually, by iteratively updating the values of the parameters in order to investigate the parameter space with user-experience driven choices. To overcome such limitation and search efficiently through the parameter space one can implement automatic techniques. Typical steps in automatic tuning are: (i) constraining the scope of the study (model, simulation setup, parameters, metrics to fit and corresponding reference values); (ii) conducting a sensitivity analysis to reduce the parameter space and/or building an emulator for the climate model; and (iii) conducting a sophisticated grid search to define the optimum parameter set or its distribution (e.g., rejection sampling and history matching). The ICOsahedral Non-hydrostatic (ICON) model is a modelling framework for numerical weather prediction and climate projections. We implement a ML-based automatic tuning technic to tune a recent version of ICON-A with a spatial resolution typically used for climate projections. We evaluate the tuned ICON-A model against satellite observations using the Earth System Model Evaluation Tool (ESMValTool). Although automatic tuning technics allow to reach the optimum parameter values in less steps than with the manual tuning, they still require some experience-driven choices throughout the tuning process. Moreover, the performances of the tuned model is limited by the structural errors of the model, inherent to the mathematical description of the parameterizations included in the model.
Impact of hail events on agriculture: A remote sensing-based analysis of hail damage in the context of climate change
Authors: Streifeneder Vanessa , Hölbling Daniel , Dabiri Zahra
Published: February 2023

In the project HAGL (“Impact of hail events on agriculture: A remote sensing-based analysis of hail damage in the context of climate change”), we analyse the effects of hail damage on agriculture. In the context of climate change and the associated increased risk of extreme weather events to society and the economy, this project deals with a locally catastrophic natural hazard that causes high costs, namely hail. Hail, combined with severe storms, causes millions of Euros of damage to agriculture every year. The influence of climate change on local weather patterns (e.g. thunderstorms) is still relatively unexplored, but early evidence points to an increase in weather patterns causing hail and an increase in hailstone sizes. In Austria, especially southeastern Styria with its various crops is frequently affected by extreme hail events. Yield losses due to hail damage can be existence-threatening for farmers, which is why an effective damage assessment is of great interest.We aim to develop an efficient method to determine the damage to agriculture caused by hail using various remote sensing data. Through a spatial hotspot analysis, we identify regions in southeastern Styria that are particularly affected by hailstorms to test and validate our method. We perform a combined analysis of Sentinel-2 optical and Sentinel-1 synthetic aperture radar (SAR) data using object-based image analysis (OBIA) methods and different vegetation indices derived from the multispectral data as well as radar backscatter signals to detect hail damage. Finally, we aim to create a damage categorisation that could support insurance work in the event of a disaster and make it more efficient by providing a first estimation of the damage before an on-side assessment is conducted. Especially for large agricultural fields, this would save time and resources by making it possible to prioritise areas with high damage and organise the fieldwork of insurance employees accordingly.
Assessment of variability and trends of the tropopause from reanalyses data
Authors: Zou Ling , Hoffmann Lars
Published: February 2023

As the boundary between the troposphere and stratosphere, the tropopause plays a key role in regulating the entrance of air from the troposphere into the stratosphere and in controlling stratosphere-troposphere exchange. In the context of global warming, investigations of the climatological characteristics and trends of the tropopause are of particular interest. In this study, the long-term variability and trends of global tropopause characteristics from 1980 to 2021 are analyzed based on data derived from the ERA5, ERA-Interim, MERRA2, and NCEP reanalyses. We find a general increase in tropical tropopause geopotential height, which is on average about 0.05 km/decade$ during 1980-2021 for the WMO lapse rate tropopause and the cold point. Over the same time period, no significant trend in tropical tropopause temperature was detected in ERA5 and MERRA2. However, the tropical tropopause temperature experiences a decrease from 1980 to the early 21st century, then changes to an increasing trend (0.2 K/decade) from 2005 to 2021 in all reanalyses. Along with the increase of the tropical tropopause height, a widening of the tropics is observed from all reanalyses. The edges of the tropics are found to be extending poleward by about 0.2°/decade in the northern hemisphere and about 0.1°/decade in the southern hemisphere. Despite the multiple challenges involved in deriving the characteristics and trends of the tropopause from global reanalysis data, this study and our open data sets will help to better inform future assessments on stratosphere-troposphere exchange and chemistry and dynamics of the upper troposphere and lower stratosphere region. 
Impact of Persistent Heatwave on Heat-Related Illness
Authors: Baek JongHyeon , Lee Sungsu , Um Jeong Ah
Published: February 2023

Since 2000, numerous people have suffered from heat-related illness and even died of the heatwave, and more than thousands of people in Korea share the similar pain and loss since 2010. The extremely high temperature and humid are known to be responsible for illness and death; however, the spatial correlation between highest temperature and occurrence of heat-related illness seems relatively low according to the previous studies. There can be many reasons for this, one of which is social aspect. Another reason of the varying probability of occurrence can be the duration of the temperature. Therefore, in this paper, in order to analyze the impacts of persistent high temperatures on the occurrence of heatwave disease, we analyzed the number of days of heatwave days and tropical night days immediately preceding the date of the onset of heat-related illness. This research was supported by a grant(2020-MOIS35-002) of Policy-linked Technology Development Program on Natural Disaster Prevention and Mitigation funded by Ministry of Interior and Safety(MOIS, Korea).