bluuebunny/crossref_metadata_2025 huggingface dataset:
Observation-constrained estimates of the global ocean carbon sink from Earth system models
Authors: Terhaar Jens , Frölicher Thomas L , Joos Fortunat
Published: February 2023

The ocean slows global warming by currently taking up around one-quarter of all human-made CO2 emissions. However, estimates of the ocean anthropogenic carbon uptake vary across various observation-based and model-based approaches. Here, we show that the global ocean anthropogenic carbon sink simulated by Earth system models can be constrained by two physical parameters, the present-day sea surface salinity in the subtropical–polar frontal zone in the Southern Ocean and the strength of the Atlantic Meridional Overturning Circulation, and one biogeochemical parameter, the Revelle factor of the global surface ocean. The Revelle factor quantifies the chemical capacity of seawater to take up carbon for a given increase in atmospheric CO2. By exploiting this three-dimensional emergent constraint with observations, we provide a new model- and observation-based estimate of the past, present, and future global ocean anthropogenic carbon sink and show that the ocean carbon sink is 9 %–11 % larger than previously estimated. Furthermore, the constraint reduces uncertainties of the past and present global ocean anthropogenic carbon sink by 42 %–59 % and the future sink by 32 %–62 % depending on the scenario, allowing for a better understanding of the global carbon cycle and better-targeted climate and ocean policies. Our constrained results are in good agreement with the anthropogenic carbon air–sea flux estimates over the last three decades based on observations of the CO2 partial pressure at the ocean surface in the Global Carbon Budget 2021, and they suggest that existing hindcast ocean-only model simulations underestimate the global ocean anthropogenic carbon sink. The key parameters identified here for the ocean anthropogenic carbon sink should be quantified when presenting simulated ocean anthropogenic carbon uptake as in the Global Carbon Budget and be used to adjust these simulated estimates if necessary. The larger ocean carbon sink results in enhanced ocean acidification over the 21st century, which further threatens marine ecosystems by reducing the water volume that is projected to be undersaturated towards aragonite by around 3.7×106–7.4×106 km3 more than originally projected.
Evaluating Agricultural Sustainability Based on theWater–Energy–Food Nexus in the ChenmengquanIrrigation District of China
Authors: Liu Chang
Published: February 2023

 Agriculture is one of the largest consumers of water and energy. This paper evaluatedthe agricultural sustainability of the Chenmengquan irrigation district of China based on thewater–energy–food nexus. One objective weighting method and one subjective weighting methodwere integrated, based on game theory, and a matter–element model was constructed to evaluateagricultural sustainability for the research region. The sensitivity of each index to the evaluation classwas also analyzed. The results showed that agricultural sustainability was moderate in 2006–2012and high in 2012–2015. The indexes, which represent water-use efficiency and yield per unit areaof crops, had higher sensitivities in the context of the present case study. The results also indicatedthat agricultural sustainability had a comparatively positive trend between 2012 and 2015, and thatpesticide utilization was the most important issue for agricultural sustainability. The approachof using the combination of a weighting method, based upon game theory, and the use of thematter–element model provides a guide for the evaluation of agricultural sustainability 
Connections of Geomorphological Activity, Geological History and Organic Carbon Storage in Steep, Mountainous Drainage Basins: A Field Investigation
Authors: Martin Yvonne , Gurung Deepa , Johnson Edward
Published: February 2023

This study investigates connections amongst geomorphological activity, geological history and organic carbon storage for trees, shrubs and herbs along valley floors of channel networks in small, steep drainage basins in the Canadian Rockies. The amount of potential storage space for organic carbon often varies considerably along valley floors in mountainous terrain due to variability in valley floor widths resulting from large-scale tectonic controls. Vegetation density on valley floors is anticipated to show significant variability along channel networks in steep terrain due to changing environmental conditions (e.g., climate, moisture, geomorphic disturbances). Valley floor widths were measured and analyzed for two steep drainage basins, Ribbon Creek and Porcupine Creek, in the Front Ranges of the Canadian Rockies. Results show that the complex tectonic history and associated geological structures and bedrock type influence valley floors widths, with no regular, discernible pattern in an upstream direction. Field surveys were undertaken to document vegetation density along these same channel networks. Geomorphological processes, such as debris flows and other mass wasting events, influence grain sizes along valley floors in the study drainage basins. Substrate characteristics, such as grain size, were found to influence vegetation density along channel networks. Finally, total organic carbon storage along valley floors is determined for Ribbon Creek and Porcupine Creek. Values of total organic carbon storage are influenced by the joint controls of potential storage space for organic carbon that results from the tectonic history and the control of geomorphological activity on substate conditions and vegetation density.
Beyond agriculture? A review of cross-sectoral drought risk and impacts research in Europe over the past two decades
Authors: Cotti Davide , Sabino Siemons Anne-Sophie , Naumann Gustavo , Wens Marthe , de Moel Hans , Blauhut Veit , Stahl Kerstin , Rossi Lauro , Maetens Willem , Toreti Andrea , Hagenlocher Michael
Published: February 2023

The impacts of drought events can be diverse, far-reaching and encompass multiple sectors and systems. This became particularly evident in recent droughts in Europe (e.g. 2018 and 2022), when, together with extensive damages to agriculture across the whole continent, severe impacts on public water supply, energy production and riverine transportation were also registered. However, while the scientific community has called for the study of these events in their multi-sectoral complexity, research on drought risk and impacts still tends to be conducted in sectoral and disciplinary silos, with different conceptualizations, terminology and methodologies evolving in relative isolation. In order to assess the state of multi-sectoral drought risk research in the European Union, we have completed a systematic literature review (n=168) aimed at understanding how different sectors and systems are represented in drought impacts and risk assessment research in the 27 countries of the European Union (EU27). The analysis focused on peer-reviewed publications and conference proceedings from 2000 to 2022, sourced through the Scopus database, and returned a research landscape where agricultural applications are predominant across the period considered, but in which the representation of other sectors and systems (e.g. energy, ecosystems) is steadily increasing throughout the years. However, only a minority of the studies tackle more than one sector or system (e.g. agriculture and ecosystems), and in most cases the multi-sectoral perspective is not accompanied by a fully integrated assessment of risk in its hazard, exposure and vulnerability components. Another trend of interest is the progressive, albeit still limited, increase in the representation of different geographical clusters among the studies analysed: in particular, while Southern European countries (e.g. Spain, Italy, Portugal) lead in number of case studies, applications to Western European countries (e.g. Germany, France, Austria) have become more frequent. These results can be interpreted as a general improvement towards a more unified understanding and characterization of drought events, but also point at a still high compartmentalization across sectoral fields. Because of the complexity of droughts, this persisting separation may hinder progress towards a common conceptualization of drought events as systemic and multi-sectoral events with multiple direct, indirect and cascading impacts. In particular, a stronger focus on multi-sectoral risk analysis could provide actionable information to support the identification of solutions capable of tackling multiple issues, thus expanding the policy space into which drought risk management can operate.
Gamma radiation for rare earth elements (REEs) in deep-sea sediments
Authors: Lee Changyoon , Kim Yuri , Kim Yoon-Mi , Hong Sung Kyung , Hong Seok-Hwi
Published: February 2023

Gamma ray is routinely used for correlation, evaluation or classification of minerals and rocks on continent and ocean. Using natural gamma radiation (NGR) derived from Integrated Ocean Drilling Program (IODP) and Ocean Drilling Program (ODP), this study focuses on the correlation between lithology and REE (Rare Earth Element)-bearing sediments in two deep-sea areas, IODP Expedition 329 in the Southwest Pacific and ODP Leg 199 Sites in the Northeast Pacific basins, where values of the REEs are abundant. Deep-sea sediments are consisting mainly of clays, calcareous oozes and siliceous oozes. As a result of the correlation, the REEs prefer to the clays rather than oozes and high values of the REEs correspond with intervals of the clays where the upper sediments (0–70 mbsf) are. The clays show relatively high values of the gamma radiation and the differences between significant elements (Th, U and K) for gamma radiation, derived from geochemical analysis at every site, show two trends reflecting characteristics of regions. Therefore we suggest that the gamma radiation is fully useful for detecting REEs in the deep-sea sediments and plays a role as a predictable tool for finding quantitative REEs. 
Effect of Snow on Streamflow Variability
Authors: Han Juntai , Yang Yuting
Published: February 2023

With the ongoing climate warming, changes in intra-annual distribution, annual volume, and their inter-annual variability of streamflow have been key research topics of ever-increasing interest. For settling the question of how changing climate shapes streamflow dynamics, here, we used long-term (1950-2010) observations of monthly streamflow (Q) for 2960 global unimpaired catchments, combined with snowfall (SF) and precipitation (P) estimates from ERA5-Land to provide a global assessment of effect of snowfall on streamflow variability. Results showed that precipitation was the main control of intra-annual and inter-annual streamflow variability while the propagation process of variability would be regulated by snow. As the snowfall fraction (sf) decreased, the annual runoff coefficient decreased, while the timing of streamflow got advanced and the intra-annual distribution became more even. Besides, the inter-annual variability of streamflow shows a negative relationship with snowfall fraction. The negative relationship between streamflow inter-annual variability and snowfall fraction may result from the asymmetric hydrological effects of snowfall in the wet and dry years.
Record-breaking rainfall accumulations in eastern China produced by Typhoon In-fa (2021)
Authors: Huang Xin , Chan Johnny C. L. , Zhan Ruifen , Yu Zifeng , Wan Rijin
Published: February 2023

Persistent heavy rainfall produced by western North Pacific (WNP) tropical cyclones (TCs) can lead to widespread flooding and landslides in Asian countries. On July 2021, unprecedent rainfall amount occurred when Typhoon In-fa passed through the highly populated eastern China. While the associated synoptic features have been analyzed, the extreme characteristics and return periods of rainfall induced by In-fa remain unexplored. Analyses of rainfall data from a WNP TC database of the China Meteorological Administration (CMA) show that Typhoon In-fa not only produces record-breaking rainfall accumulations at individual surface stations, but generates unprecedent rainfall amounts for the whole area of eastern China. Quantitatively, 2, 4, 11, 24 and 55 stations are exposed to once in 200-, 100-, 50-, 20- and 10-year extreme TC rainfall accumulations, respectively, and total rainfall at 75 stations reaches a record high since 1980. Overall, the return period is up to ~481 years for the total rainfall amount accumulated in eastern China during the 1980-2019 baseline. The extremely long rainfall duration is identified as key to the torrential rains in the Yangtze River Delta before In-fa changes its direction of movement from northwestward to northeastward, while the extreme rain rate plays a dominant role in the northern areas afterwards. Probabilities of occurrence of such an unprecedented TC rainfall event have increased in most (~75%) of the eastern China during the period of 2000-2019 compared with those during 1980-1999. Our study highlights the likely increase in risk of extreme TC-induced rainfall accumulations which should be considered in disaster risk mitigation.
Integrated urban water management modeling under future water demand and climate scenarios for the city of Bangalore, India
Authors: Mohapatra Snigdha Sarita , Arora Meenakshi , Wu Wenyan , Tiwari Manoj Kumar
Published: February 2023

Climate change and population growth have a significant impact on urban water supplies. This is due to the fact that meeting urban water demand with the available water resources is quite challenging due to ever-growing water demand, variable supply as a result of climate uncertainties, and water pollution. In many urban areas around the world, the concept of integrated urban water management (IUWM) has become quite prominent in recent decades to tackle the challenges of urban water supply and management. The main principle of IUWM is to incorporate non-conventional water supply sources, such as stormwater, rooftop rainwater, and recycled wastewater, to augment the water supply and provide fit-for-purpose water. IUWM, if implemented successfully, has the potential to mitigate multiple challenges outlined above including enhanced water security during droughts, reduced waste streams, reduced floods, and enhanced groundwater recharge as well as reduced water pollution.In this research, an IUWM principles incorporated water balance model (i.e., developed using eWater Source Version 5.4.0.11797) was used to identify the most suitable supply options from multiple water sources to satisfy the water demands under future demand and climate scenarios for the city of Bangalore, India. Five different water supply configurations were generated based on available water sources and within the policy framework to meet water demand. The effect of climate change has been incorporated into the IUWM model configurations through the runoff responses from future precipitation and temperature changes. Future climate change scenarios for four IPCC emission scenarios i.e., ssp126, ssp246, ssp323, and ssp586 have been incorporated from thirteen Coupled Model Intercomparison Project-6 (CMIP6) models (i.e., 0.25° spatial resolution available at the study location). Three water demand scenarios i.e., low (150 liters per capita per day), average (175 liters per capita per day), and high (200 liters per capita per day) for the projected population were considered as per the Indian Standards. The selected configurations were evaluated for water supply reliability (i.e., time and volumetric reliability) in the study area. Further, as multiple future scenarios resulted in multiple water supply reliability solutions under five IUWM model configurations, the robust solution was identified using robustness metrics.
New Insights into Global Plume Buoyancy and Heat Fluxes from Numerical Models of Plume-Lithosphere Interaction
Authors: Ma Ziqi , Ballmer Maxim
Published: February 2023

Earth's dynamic evolution is controlled by the interplay between mantle convection and plate tectonics. While subducted plates stir the mantle, upwelling plumes can lubricate, push, and break up plates. As the surface expression of upwelling plume dynamics, the plume buoyancy flux is traditionally estimated as the cross-sectional area of the hotspot swell multiplied by plate velocity (for intraplate hotspots) or multiplied by the full-spreading rate (for ridge-centred hotspots).This classical approach implies two big assumptions: that the swell is fully isostatically compensated by the hot ponding plume material at the base of the lithosphere; and that this plume material spreads at exactly the same speed as the overriding plate moves. However, geophysical observations and numerical models demonstrate that those assumptions are wrong. Hotspot swells are largely dynamically instead of fully isostatically compensated; to some extent, swells are further compensated by sublithospheric erosion [1]. Moreover, at least some plumes spread faster than plate motion [2]. For example, evidence in the North Atlantic from prominent V-shaped ridges, ephemeral landscapes, and off-axis uplift of oceanic gateways suggests that along-axis asthenospheric velocities can be an order of magnitude faster than the full plate-spreading rate near Iceland [3]. Thus, classical estimates for the buoyancy fluxes of deep-seated mantle upwellings may be strongly biased by surface-plate velocities [4]. Alternative estimates of plume buoyancy flux assume a constant swell decay timescale [4] but without any physical underpinning. As detailed estimates of dynamic seafloor topography are now available [5], it is time to revisit the buoyancy fluxes and, thereby, the mass and heat fluxes carried by mantle plumes.Here, we explore high-resolution regional-scale geodynamic models with a free surface to study plume-ridge interaction and swell compensation. We consider composite diffusion-dislocation creep in our models. We investigate the effects of plume temperature/radius, plate velocity (or spreading rate for ridge-centred hotspots), and mantle rheological parameters on plume-lithosphere interaction and swell support. Preliminary results demonstrate that plume spreading is significantly faster than plate motion for intermediate-to-large plumes at realistic rheological conditions. From this result, we update estimates of plume buoyancy fluxes, showing that the total heat flux carried by plumes across the core-mantle boundary is significantly larger than previously thought.  Reference List1. Cadio et al., 2012; doi:1016/j.epsl.2012.10.0062. Ribe & Christensen, 1999; doi:10.1016/S0012-821X(99)00179-X3. Poore et al., 2011; doi: 10.1038/ngeo11614. Hoggard et al., 2020; doi: 10.1016/j.epsl.2020.1163175. Hoggard et al., 2016; doi: 10.1038/ngeo2709
A Water Resource Allocation Model Based on Coupled Socio-economic-Environment-Ecology-Resources System
Authors: Shi Yujia , Wang Zhongjing , Chen Jiahui , Chen Jibin
Published: February 2023

With the ongoing economic development and population growth, the shortage of water resources has become a severe problem which involves conflicts and tradeoffs among society, economy, environment, and ecology. Although previous researches proposed multi-objective optimization models, human-water coupled models, and hydro-economic models to deal with these conflicts and tradeoffs, they still did not address water demands’ integration and lacked future vision of water resource allocation. This paper proposed a Water Resource Allocation Model based on coupled Socio-economic-Environment-Ecology-Resources System (WRAM-SEERS) which considered integrally optimization objectives of socio-economic, environmental, and ecological subsystems under the constraints of water and land resources. The proposed model has the following advantages: (a) It could reflect all the closely related elements of the evolution of human society including urban and ecological space planning, cultivated structure and scale, population structure and size, industrial structure and scale, and so on, (b) It could generate the Pareto frontier surface, which maximized the socio-economic interest while minimizing the adverse externalities reacting in environment and ecology, and (c) It could forecast the future development range of each subsystem under hydrologic uncertainties. We applied WRAM-SEERS to allocate water resources of Yinchuan City in China in 2021-2035 and explained issues related the future perspective of Yinchuan: (a) “what is the lower and upper limits of subsystems’ development targets”, (b) “how to set targets consistent with sustainable development”, and (c) “how to achieve the settled targets”. The above explanations provided a scientific basis and decision-making reference for improving the water safety guarantee ability of Yinchuan's economic and social development and promoting a green, sustainable and high-quality development.
Reduced moisture sources contributed to the 2017-2019 southeast Australian drought
Authors: Taschetto Andréa S. , Stojanovic Milica , Holgate Chiara , Drumond Anita , Evans Jason , Gimeno Luis , Nieto Raquel
Published: February 2023

The Murray Darling Basin, located in southeast Australia, is an agriculturally rich area, providing one-third of the country’ food supply. In 2017-2019 the region experienced one of its worst droughts since 1900. Rainfall in the Murray Darling Basin was consistently below average for three consecutive cool seasons, an unprecedented event on record. The drought set the extreme conditions that led later to the 2019-2020 Black Summer Bushfires. Previous studies suggest that the strong 2019 positive Indian Ocean Dipole intensified the conditions of the drought, however the state of the climate drivers cannot fully explain the onset and development of the Murray Darling Basin drought. In this study, we investigate processes other than remote climate drivers that may have triggered the drought. Using a Lagrangian model to backtrack moisture sources to southeast Australia, we show that local processes were crucial in explaining the onset and development of the drought. We identify the sources of moisture to the cool season precipitation over the Murray Darling Basin and show for the first time that the moisture supply from the Tasman Sea declined in 2017 and 2018. We further show that the expected moisture was instead transported northward by an anomalous anticyclonic circulation. Our results provide an explanation for the moisture and rainfall deficit that caused the 2017-19 drought. Understanding the processes that led to the 2017-2019 Murray Darling Basin drought is important for predicting and planning future multi-year droughts in Australia.
Contribution of tropical cyclone seeds in the poleward shift of the tropical cyclone formation
Authors: Chu Jung-Eun , Timmermann Axel , Raavi Pavan Harika , Lee Sun-Seon , Chan Johnny C. L. , Cheung Hung Ming
Published: February 2023

Tropical cyclones (TCs), the generic name for typhoons, are among the most destructive natural hazards. It is important to understand how climate change affects TC frequency, to minimize human and economic losses. Some studies have suggested that the number of TCs will decrease, and their formation will shift poleward. However, there is a major lack of fundamental understanding of the origin and development of the TCs from the initial precursory vortex, called a TC seed. The changes in the number of TC seeds and their survival rate (i.e., the proportion that successfully develops into TCs) will eventually control the future TC frequency. However, key challenges are mainly due to a lack of consensus in TC seed definition and a lack of computing resources for TC modeling.This study aims to meet the above challenges, through the following three tasks: (1) to identify the representation of TC seeds based on three different definitions from early-stage to matured stage; (2) to investigate the future changes in TC seeds and survival rate and their contribution to the poleward shift in TC genesis location; and (3) to unravel the physical mechanisms responsible for the change in response to climate change. We use a high-resolution fully-coupled Community Earth System Model (CESM) with an atmospheric resolution of 0.25° and an ocean resolution of 0.1° with present-day, doubling, and quadrupling CO2 concentrations. Our results show TC seeds defined by early-stage definition show more equatorward distribution with a strong connection to vertical velocity than those defined by matured stage. Interestingly, all three definitions exhibit a statistically significant reduction in the frequency of TC seeds while that in survival rate is not significant. Details of the methods and mechanisms will be further discussed during the presentation. The outcomes of this project will strengthen fundamental scientific knowledge of the TC seeds and their future change mechanisms, as well as provide a scientific basis for future risk assessment and precautionary strategies.
Cryospheric-hydrologic modeling and prediction of a mountainous catchment in the northeast Tibet Plateau
Authors: Gao Hongkai , Chang Zehua , Han Chuntan , Chen Rensheng , Wang Kang , Fenicia Fabrizio , Savenije Hubert
Published: February 2023

Increased attention directed at cryosphere hydrology is prompted by climate change. In spite of an increasing number of field measurements and modeling studies, the impact of cryospheric change, especially of frozen soil, on hydrological processes at the catchment scale is still largely unclear. Traditional frozen soil hydrology models have mostly been developed based on a “bottom-up” approach, i.e. by aggregating prior knowledge at point scale, which is an approach notoriously suffering from equifinality and uncertainty. Therefore, in this study, we explore the impact of frozen soil at catchment-scale, following a “top-down” approach, implying: expert-driven data analysis -> qualitative perceptual model -> quantitative conceptual model -> testing of model realism -> future prediction. The complex mountainous Hulu catchment, northeast of the Tibet Plateau (TP), was selected as the study site. Firstly, we diagnosed the impact of frozen soil on catchment hydrology, based on multi-source field observations, model discrepancy, and our expert knowledge. Two new typical hydrograph properties were identified: the low runoff in the early thawing season (LRET) and the discontinuous baseflow recession (DBR). Secondly, we developed a perceptual frozen soil hydrological module, to describe the LRET and DBR properties. Thirdly, based on the perceptual model and a landscape-based modeling framework (FLEX-Topo), a semi-distributed conceptual cryosphere-hydrologic model (FLEX-Cryo) has been developed, considering all cryospheric factors, including glacier and snow accumulation/ablation, and soil freeze/thaw processes. The results demonstrate that the FLEX-Cryo model can represent the effect of soil freeze/thaw processes on hydrologic connectivity and groundwater discharge and significantly improve hydrograph simulation. Furthermore, its realism has been confirmed by alternative multi-source and multi-scale observations, particularly the freezing and thawing front in the soil, the lower limit of permafrost, and the trends in groundwater level variation. In the end, we used the FLEX- Cryo model to predict the impacts of future climate change on hydrology, including the glacier retreat, the decreasing snow cover area, and permafrost degradation. The FLEX- Cryo model is a novel conceptual cryosphere-hydrologic model, which represents these complex processes and has potential for wider use in the vast TP and other cold mountainous regions.
The Effect of Arctic Vertical Warming on East Asia temperature variability on a monthly time scale and its predictability.
Authors: Kim Gaeun , Lee Woo-Seop , Kim Baek-Min
Published: February 2023

Recent studies have widely discussed arctic warming and its effect on the temperature variability over Eurasia. They agreed that Eurasia is cold while the arctic is warm during the boreal winter. Yet, the differences in month-to-month features and their predictability have not been examined. In this research, we categorized Arctic vertical warming into four types – Deep Arctic Warming (DAW), Shallow Arctic Warming (SAW), Arctic Warming Aloft, and Others – based on the vertical temperature distribution in the Barents-Kara Sea. And we discussed two significant events, DAW and SAW, which are closely related to the cold event over East Asia. The result shows that the temperature variability over East Asia associated with the Arctic events is significant in January and February but not in December. The multi-model ensemble of seasonal prediction models can distinguish the four types of Arctic events well than the individual models. In contrast, the individual models show better skill in reproducing the circulation patterns associated with the DAW than MME. Models tend to exhibit higher predictability over Eurasia in January and February compared to December. We suggest that this is partly due to the models' better representation of DAW in those months,  which is helpful for the better simulation of Arctic-midlatitude linkage. 
Development of PBL Parameterization Emulator using Neural Networks
Authors: Jang Jiyeon , Oh Tae-Jin , An Sojung , Park Wooyeon , Na Inchae , Kim Junghan
Published: February 2023

Physical parameterization is one of the major components of Numerical Weather Prediction system. In Korean Integrated Model (KIM), physical parameterizations account for about 30 % of the total computation time. There are many studies of developing neural network based emulators to replace and accelerate physics based parameterization. In this study, we develop a planetary boundary layer(PBL) emulator which is based on Shin-Hong (Hong et al., 2006, 2010; Shin and Hong, 2013, 2015) scheme that computes the parameterized effects of vertical turbulent eddy diffusion of momentum, water vapor, and sensible heat fluxes. We compare the emulator performance with Multi-Layer Perceptron (MLP) based architectures: simple MLP, MLP application version, and MLP-mixer(Tolstikhin et al., 2021). MLP application version divides data into several vertical groups for better approximation of each vertical group layers. MLP-mixer is MLP based architecture that performs well in computer vision without using convolution and self-attention. We evaluate the resulting MLP based emulator performance. MLP application version and MLP-mixer showed significant performance improvement over simple MLP.
Characterization of coarse-grained sediment supply for the assessment of soil erosion in mountainous areas. Application to the Upper Llobregat River Basin (Pyrenees, Spain)
Authors: Rodriguez Stephania , Hürlimann Marcel , Medina Vicente , Torra Ona , Oorthuis Raül , Puig Polo Càrol
Published: February 2023

In the scope of soil erosion modeling few attempts have been made to assess the coarse-grained sediments at steep slopes. The current approach results in a lack of correspondence in mountain watersheds because most models perform validation for different scales, topography, and land use, especially in the agricultural field. Available models normally prioritize the estimation of fine sediment in the field while the contribution of course-grained sediment is simplified or even neglected, especially in areas that require an analysis of hillslope failure events. Herein, we selected the Upper Llobregat River Basin (Pre-Pyrenees, Spain) as a study area and focus on the 1982 rainstorm, which triggered more than 1000 mass movements. The present investigation aims to allow an assessment of sediment production that focuses on the characterization of coarse sediment source areas from a mountain range.The methodology includes analysis through geomatic methods, field surveys, and historic landslide inventories, followed by an index connectivity calculation to main rivers, morphometric parameters, and triggering factors. Preliminary results of this ongoing study confirm the importance of hillslope processes for the assessment of the sediment budget in mountainous areas. The outcomes will be incorporated into a modular sediment-budget model, which will be calibrated in our study area and tested in other watersheds in the Pyrenees. In addition, the impact of future changes (climate and land use) will be analyzed since extreme weather scenarios strongly affect both the production and transport of sediment in mountainous areas.
Numerical Modeling of Capillary Hysteresis and Coupled Elastoplasticity for Geological Carbon Storage
Authors: Yoon Hyun Chul , Kim Jihoon
Published: February 2023

When CO2 is injected into the saline aquifer or depleted reservoir for geological carbon storage, physical processes are tightly coupled, affecting CO2 flooding and its trapping mechanisms.For example, injection induces pore pressure build-up and dilation of pore space, which can uplift the ground surface or tensile/shear failure of the caprock which may result in the leakage of CO2. Thus, rigorous analyses of coupled flow and geomechanics are necessary to predict the long-term security of geological carbon storage. In this study, we focus on two irreversible (path-dependent) processes that are coupled through flow and geomechanics: hysteretic capillary pressure in flow and elastoplasticity in geomechanics. Hysteresis in capillary pressure during drainage and imbibition processes can be seen as mechanical energy dissipation. We employ our previously proposed numerical model based on the 1D elastoplasticity algorithm for constitutive relation of the hysteretic capillary pressure in two-phase flow, i.e., capillary pressure and irreducible water saturation. In particular, we model the irreducible (plastic) water saturation being attributed to the part from the hysteretic capillary pressure, which yields a mathematically well-posed problem. We implement the irreversible flow and geomechanics simulation, calculating the residual saturations and plastic strain from each iteration of flow and geomechanics, as we employ the fixed-stress sequential method solving coupled flow and geomechanics.From the numerical experiments, we find robust computations of the coupled processes, highlighting the coupled effects of capillary hysteresis and elastoplasticity. As residual/capillary and structural trappings are major trapping mechanisms for CO2 geological storage, the proposed constitutive relation and algorithm for coupled path-dependent processes can predict flooding and trapping of CO2 underground more accurately.  
Resolving the rupture directivity and seismogenic structure of the 2018 Taiwan Shoal MW5.7 earthquake
Authors: Tang Lanlan
Published: February 2023

On November 26, 2018, a Mw5.7 earthquake occurred on the northern edge of the Taiwan Shoal. The epicenter was not on the known deep fault, and the direction of the rupture was doubtful due to the lack of near-station control. Based on the broadband station recordings in Fujian, Guangdong and Taiwan, we use microseismic detection technology to obtain a more complete aftershock sequence. The number of detected aftershocks is 4 times that of the Fujian network catalogue. These aftershocks are distributed in a 2*10 km east-west trending strip. In addition, the focal mechanism solutions of the main shock and five strong aftershocks were inverted by the GCAP method. The inversion results showed that the main shock and the strong aftershocks were both strike-slip earthquakes with high dip angles, and the principal compressive stress direction was in the NW-SE direction. The obtained focal depths are slightly different, the focal depth of the main shock is 14 km, and the focal depth of strong aftershocks above Mw3.9 is between 12 and 17 km. There are significant differences in aftershock activities between the east and west of the main shock. The aftershock activities on the east are mainly concentrated within one month after the main shock, while the aftershock activities on the west continued to be active within the six months after the main shock, indicating that the stress on the east side is relatively fully released after the main earthquake. Moreover, the multi-channel seismic profiles passing through the epicenter reveal that the shallow active faults in the epicenter are EW, with significant strike-slip characteristics, and their spatial locations are consistent with the distribution of aftershocks and the focal mechanism solution. Based on the temporal-spatial distribution of aftershocks, focal mechanism solutions and the characteristics of shallow active faults, we inferred that the seismic fault of the Mw5.7 earthquake is a near east-west trending Taiwan Shoal Fault, which may be an extension of the B Fault of Taiwan Island. The strong right-handed shear stress in the upper crust generated by the lateral subduction rate difference is the dynamic cause of the 2018 Taiwan Shoal Mw5.7 earthquake.
Landscape-scale links between microbial ecology and surface processes
Authors: Ben-Israel Michal , Lukens Claire E. , Peyakov Kolleen , Beman J. Michael
Published: February 2023

Microbial activity on Earth’s surface is key in the decomposition of organic matter and humus formation, carbon sequestration, cycling of rock-derived nutrients, and the development of soil structure and stabilization. While the role of microbial life in various weathering processes has been demonstrated experimentally and observed at the nanometer-centimeter scale, the obvious link between microbial life activity and landscape-scale geomorphic processes remains unexplored.We examined the reciprocal relationship between microbial communities and rates of surface processes in recently deglaciated landscapes in the eastern Sierra Nevada Mountains, California, USA. Sampling along an elevational transect in a glacial basin in the high Sierra (between 2800 and 3050 masl), we quantify exposure ages and rates of soil production using cosmogenic nuclides and examine microbial community ecology in the same rocks and soils. Exposure ages from cosmogenic 10Be indicate rapid deglaciation around 12-13 ka and relatively fast soil production rates (~4.3-4.5 cm/kyr), independent of elevation.To understand how these rapid soil production rates correlate with microbial community composition and diversity, we extracted and sequenced environmental DNA from near-surface soils, saprolite samples, and exposed surface rocks. Microbiome sequencing results constrain changes in microbial ecology from rock to soil, shed light on the complex relationship between microbial community dynamics, and weathering rates in the eastern Sierra, and help us to better understand the link between life and landscape evolution.
years of observations of earthquakes with Swarm satellites: results and open questions
Authors: Zhu Kaiguang , Marchetti Dedalo , Fan Mengxuan , Wang Ting , Zhang Yiqun , Chen Wenqi , Cheng Yuqi , Wen Jiami , Zhang Hanshuo , Zhang Donghua , Shen Xuhui , Zhima Zeren , Yan Rui
Published: February 2023

The Swarm mission was successfully launched in November 2013 and it’s still in orbit and providing global continues measurements of Earth’s magnetic field and plasma parameters such as electron density (Ne).In this presentation, several examples of research of pre-earthquake electromagnetic phenomena in the occasion of medium (M6+) or large (M7.5+) seismic events by using Swarm magnetic and electron density data will be shown. In most cases, an acceleration of the Y-East magnetic component of the anomalies has been detected one week to months in advance with respect to the incoming earthquake.A recent study, based on the first 8 years of Swarm magnetic field and Ne data, shows statistical proof of the correlation between Swarm anomalies and incoming M5.5+ earthquakes. In particular, it was identified that the anticipation time of the anomalies increases with earthquake magnitude and in addition that earthquakes with an epicentre on the sea tend to show higher frequency (period = 2s-10s) anomalies than land earthquakes (period = 25s-50s). A possible influence of the focal mechanism was also investigated but the results are not statistically significant and further studies are necessary.On 2nd February 2018, China successfully launched its first satellite completely dedicated to studying earthquakes, called China Seismo-Electromagnetic Satellite (CSES-01) or ZhangHeng-01 (ZH-01). CSES-01 is equipped with several payloads to measure the magnetic and electric fields, ionospheric plasma properties, and two particle detectors with the purpose of understanding the possible ionospheric disturbances induced by earthquakes. This data from CSES-01 allowed us to better understand the ionospheric environment together with the Swarm mission and we will show how the join use of the two missions can highly help to characterize the ionosphere and possible pre-earthquake phenomena. For example, before the occurrence of Mw=7.5 Indonesia 2018, Mw=7.1 Ridgecrest 2019 or Mw=7.7 Jamaica 2020 earthquakes, an enhancement of the electron density has been detected and better described by multi-missions (Swarm and CSES) investigation.Finally, a test of the quasi-real-time application of Swarm data to monitor earthquakes will be shown. In fact, a very quick investigation of the seismicity that occurred North of Rome, Italy (Guidonia city) on December 2022 and 1st January 2023 (ML=3.3) has been conducted identifying an anomalous Swarm track which is compatible with seismic acceleration that occurred before these events, but further explanations are possible. This test, even if still a manual analysis shows the capability to implement in near future an automatic monitoring system which could get further advantage from the Swarm data produced by the proposed FAST processor by ESA, even though not strictly crucial. 
Improvement of the dust retrieval algorithm using GK-2A Geostationary satellite by updating Asian dust chemical composition
Authors: Parsa Javid Ehsan , Park Sang Seo
Published: February 2023

Dust storms often occur in the spring season and influence large areas of Korean peninsula. During a dust storm event, the concentration of dust particles in the atmosphere increases significantly. Satellite monitoring is a powerful tool for studying the properties of large-scale dust storms. however, amidst all uncertainties associated with aerosol properties, the inadequate information about the chemical composition of the dust also greatly affects the radiation field at the top of atmosphere (TOA). GEO-KOMPSAT-2A is a South Korean geostationary meteorological satellite for the meteorological mission and the space weather monitoring mission. It has been equipped with AMI (Advanced Meteorological Imager) and KSEM (Korean Space Environment Monitor) payloads. In this study, an algorithm will be investigated that uses four infrared channels: 8.6 μm, 10.4 μm, 11.2 μm and 12.4 μm, on the AMI. updating Asian dust components according to 25 samples collected during 14 Asian dust events occurring between 2005 and 2018 on the Korean Peninsula and compared them to 34 soil samples (<20 µm) obtained from the Mongolian Gobi Desert, which is a major source of Asian dust will be presented. We used the libRadtran radiative transfer model for simulation of the atmospheric condition, presence of the aerosols and radiance reaching TOA. according to the refractive index and size distribution dataset of new components and strong dependency of TIR wavelength bands to the optical properties of the dust we expect this method will increase the accuracy of the algorithm.
Record-breaking High Temperature in July 2021 over East Sea and Possible Mechanism
Authors: Kwon MinHo , Lee Kang-Jin , Kang Hyun-Woo
Published: February 2023

As climate change due to global warming continues to be accelerated, various extreme events become more intense, more likely to occur and longer-lasting on a much larger scale. Recent studies show that global warming acts as the primary driver of extreme events and that heat-related extreme events should be attributed to anthropogenic global warming. Among them, both terrestrial and marine heat waves are great concerns for human beings as well as ecosystems. Taking place around the world, one of those events appeared over East Sea in July 2021 with record-breaking high temperature. Meanwhile, climate condition around East Sea was favorable for anomalous warming with less total cloud cover, more incoming solar radiation, and shorter period of Changma rainfall. According to the results of wave activity flux analysis, highly activated meridional mode of teleconnection that links western North Pacific to East Asia caused localized warming over East Sea to become stronger. 
NECKLACE: A circum-Antarctic dataset of basal melt
Authors: Cook Sue , Nicholls Keith W. , Vaňková Irena , Thompson Sarah S. , Stewart Craig L.
Published: February 2023

Ocean-driven melt at the base of floating ice shelves is a major mass loss process from the Antarctic ice sheet, and a key component in accurately predicting its contribution to future sea level rise. Observations of basal melt are important tools for testing and improving models of ice shelf-ocean interaction. While many of these observations come from satellite methods, field observations of melt are valuable for validating satellite-derived data products, and to provide higher-temporal resolution timeseries of melt.The NECKLACE project aims to collate field measurements of ice shelf melt to create a standardised data product that can be used by glaciologists, oceanographers, and ice sheet modellers for testing and validation. Field measurements of melt can use a range of techniques, including range finding from under-ice moorings and surface radar instruments, but the most commonly used instrument in recent years is the Autonomous phase-sensitive Radio Echo Sounder (ApRES) due to its low cost and ease of deployment. The project will combine data contributions from multiple international teams to create a continent-wide, open-access database of timeseries of basal melt rates. The initial dataset will contain contributions from over 40 sites on 12 ice shelves. Beyond the collation of existing data, the project team also aims promote the collection of new field data by providing assistance with equipment procurement, set-up, and data processing. We hope that this data product can provide the basis for an ongoing monitoring network observing basal melt around Antarctica.
Toward diurnal observations of tropospheric NO2 from Chinese polar-orbiting satellite series
Authors: Zhang Chengxin , Liu Cheng
Published: February 2023

Nitrogen oxides (NOx=NO2+NO) play an important role in atmospheric chemistry and human health. Satellite measurements of atmospheric NO2 have been made available by satellite ultraviolet‒visible spectrometers such as GOME, SCIAMACHY, OMI, and TROPOMI. To enhance the stereoscopic monitoring of air quality, China has launched the series of Environmental trace gases Monitoring Instruments (EMI) onboard multiple satellites including GaoFen-5 (2018 May–2020 April), GaoFen-5A (since 2022 December), GaoFen-5B (since 2021 September), and DQ-1 (since 2022 April), as well as more satellites to be planned. The EMI-series instruments can measure NO2 at two local overpass times, i.e., 10:30 in the morning (DQ-1) and 13:30 in the afternoon (others), with a nadir spatial resolution of 12×13 km2. In this study, we optimized a consistent retrieval algorithm for tropospheric NO2 from the EMI series by fitting spectra with an earthshine reference over the remote ocean, masking cloudy pixels by the cloud fraction, and calculating the air mass factor by using high-resolution a priori profiles from a global chemical model and surface Lambertian-equivalent reflectivity. We have compared the EMI NO2 retrievals with ground-based remote sensing measurements from NDACC, TCCON and other MAX-DOAS networks, as well as other satellites such as OMI, TROPOMI and GEMS. In general, both ground and satellite validations show good correlations and high precision of EMI NO2 datasets. Finally, we explored the potential of detecting the diurnal variability of atmospheric NO2 in different global cities by using EMI NO2 observations. Such diurnal patterns can be helpful for the understanding of atmospheric chemistry and the design of geostationary satellite instruments in different global regions.