bluuebunny/crossref_metadata_2025 huggingface dataset:
Comprehensive flood risk assessment of urban flooding based on the 1D/2D coupled hydrodynamic model
Authors: Dong Boliang , Huang Bensheng , Tan Chao , Gao Shuailing , Xia Junqiang
Published: March 2024

In urban environments, urban flooding can lead to significant economic losses due to high population density and valuable economic properties. The complexity of urban flood disasters and the diverse entities affected present substantial challenges for accurate flood risk assessment. In response to this critical need, we have developed a comprehensive urban flood risk assessment method that evaluates the flood risk for primary affected entities, including residents' lives, ground buildings, and underground spaces. This proposed assessment method is based on both scenario analysis and the index system method. Initially, it predicts the disaster-causing hydraulic characteristics, such as water depth, flow velocity, and building inundation, using a high-performance 1D/2D coupled urban flood hydrodynamic model. Subsequently, it assesses the flood risk of disaster-affected objects, such as people, ground buildings, and underground spaces, based on hazard, vulnerability, and exposure indices. We successfully applied this comprehensive urban flood risk assessment method to a highly developed urban area in Wuhan City, China. To address the challenge of data acquisition, we utilized web crawling to gather information on industrial distribution, property prices, and shop rents to support flood risk analysis. The flooding process and corresponding risk levels of primarily affected objects under different rainfall return period scenarios were comprehensively evaluated. The established model can serve as a reference for disaster prevention and reduction technologies for other cities threatened by urban flood disasters.
Effects of biofouled plastics on phytoplankton community assembling and water chemistry: pilot study and implications for freshwater environments
Authors: Binda Gilberto , Carnati Stefano , Costa Margarida , Hostyeva Vladyslava , Leu Eva , Skjelbred Birger , Spanu Davide , Šupraha Luka , Trotta Sara , Vogelsang Christian , Nizzetto Luca
Published: March 2024

The presence of plastic litter and microplastics in freshwaters has raised concern about their potential transport and accumulation in water and sediments over time. However, several direct and indirect environmental consequences are still not well understood. In this study, we investigated the role of plastic as a carrier of algal species favouring their dispersal in freshwaters, and we assessed the potential effects on water biodiversity and chemical features in a pilot, laboratory-based study. We simulated an algal community using 5 algal species commonly found in freshwaters and we exposed this community to both pristine and biofouled polypropylene fragments of 5 × 5 × 0.3 mm in size. The biofouled plastic was generated by incubating similar polypropylene fragments with 2 other freshwater algal species, which were different from those in the simulated community. In addition, we evaluated the effect of the dispersal of algae from plastic without the presence of a simulated pelagic community. The experiment lasted 15 days in total. At different time intervals, we assessed: total algal growth and photosynthetic efficiency, algal community composition and the concentration of macronutrients and minor elements in the water. We observed changes in the algal community composition and marked chemical alterations driven by the presence of the biofouled plastics. The presence of pristine plastic, instead, did not show significant changes in the community composition and in the concentration of dissolved elements. The dispersal of algal species from the biofilm on plastic and competitive interactions between the plastic biofilm and the pelagic community were, therefore, likely responsible for the changes in the algal diversity. These results confirmed the hypothesis that plastic can influence dispersal and biodiversity of the algal community. Biofouled plastic from environmental samples and environmental communities selected from natural freshwater bodies will be used in future experiments. This will help to unravel the potential consequences of plastic pollution for ecosystem functioning and microbial biodiversity.
Applications of Data Assimilation and Parameter Calibration with Multi-Resolution Measurements of Seawater Temperature for Hydrodynamic Modeling of Shallow, Tidal Environments
Authors: Alsulaiman Nada , Van Reeuwijk Maarten , Piggott Matthew
Published: March 2024

This study investigates the integration of seawater temperature data acquired through in-situ and remote sensing methods, aiming to enhance the accuracy of hydrodynamic models. Our focus is on a shallow bay influenced by semidiurnal tides, where continuous thermal discharges from a coastal power plant significantly impact the local temperature field. The investigation addresses the model's uncertainty in capturing the variability of thermal effluents, particularly regarding the input descriptions for the discharge rate (Q) and excess temperature (ΔT) added to the ambient waters. These parameters display seasonal variations that reflect the energy consumption trends of the local population, introducing complexity into seawater temperature modeling. We aim to assess the effectiveness of using different data types in two key application areas: (A) generating better initial conditions through data assimilation with the Ensemble Kalman Filter (EnKF) technique, and (B) automating the calibration of the model parameters for the description of the thermal discharge. To explore these applications, we conduct a twin experiment that replicates the bay's real-world conditions, allowing for a comprehensive evaluation of the impact of integrating temperature data of varying resolutions on the assimilation and calibration processes. Our goal is to determine the most effective spatiotemporal scales for these applications, and to provide recommendations for modeling approaches in similar tidal environments.
Artificial light at night reveals hotspots and rapid development of industrial activity in the Arctic
Authors: Akandil Cengiz , Plekhanova Elena , Rietze Nils , Oehri Jacqueline , Roman Miguel O. , Wang Zhuosen , Radeloff Volker , Schaepman-Strub Gabriela
Published: March 2024

Climate warming enables easier access and operation in the Arctic, fostering industrial and urban development. However, there is no comprehensive pan-Arctic overview of industrial and urban development, which is crucial for the planning of sustainable development of the region. In this study, we utilize satellite derived artificial light at night (ALAN) data to quantify the hotspots and the development of human activity across the Arctic from 1992 – 2013. We find that out of 16.4 million km2 analyzed a total area of 839,710 km2 (5.14%) is lit by human activity with an annual increase of 4.8%. The European Arctic and the oil and gas extraction regions in Russia and Alaska are hotspots of ALAN with up to a third of the land area lit, while the Canadian Arctic remains dark to a large extent. On average, only 15% of lit area in the Arctic contains human settlement, indicating that artificial light is largely attributable to industrial human activity. With this study, we provide a new, standardized approach to spatially assess human industrial activity across the Arctic, independent from economic data. Our results provide a crucial baseline for sustainable development and conservation planning across the highly vulnerable Arctic region. 
Comparing the distribution and development of Urban Green Spaces in the two Vietnamese delta cities Hanoi and Ho Chi Minh City
Authors: Scheiber Leon , Zühlsdorff Vera , Son Ngo Than , Duong Nong Huu , Quan Nguyen Hong , Garschagen Matthias , Reimuth Andrea
Published: March 2024

Promoting public access to Urban Green Spaces is a central objective in sustainable city planning. Urban Green Spaces can play a vital role in enhancing various aspects of public life, including human recreation, local climate regulation and rainwater infiltration. However, in most metropolitan areas, especially in developing countries and emerging economies, Urban Green Spaces face competition with strong economic interests leading to their deterioration over the last decades. Our study critically examines this assumption for two Vietnamese delta cities, namely Hanoi and Ho Chi Minh City. In particular, we use multi-spectral satellite imagery from the Sentinel-2 mission to create seasonal maps of the Normalized Difference Vegetation Index in order to estimate the local proportion of densely vegetated areas. By blending these maps with population data from the National Census of 2019, we determine the spatial distribution of Urban Green Spaces per capita in both cities and interpret these findings against the background of recent spatial planning efforts. Spanning seven dry seasons in total (Dec 2016 – Jan 2023), the satellite data furthermore allow us to compare the temporal development of Urban Green Spaces and tentatively extrapolate these trends into the near future. Our preliminary results suggest that districts with particularly high percentages of Urban Green Spaces in Hanoi generally encompass the historic city core, while the greenest districts of HCMC are located in the newly established city-within-city Thu Duc east of the Saigon River. Moreover, the Urban Green Space per capita in Hanoi is nearly twice as high as in Ho Chi Minh City amounting to 11.6 and 6.8 square meters, respectively. Judging from the NDVI time series, these figures seem relatively stable with variations in the order of 1 square kilometre per year. Yet, ongoing urbanization trends will put stress on both the proportion of Urban Green Spaces and the number of inhabitants benefitting. Even though the stability of the Normalized Difference Vegetation Index is subjected to atmospheric and climatic boundary conditions, we can report that measurement-inherent variations in our study only accounted for standard deviations below 0.1 at selected locations with constant land cover. Consequently, the applied methodology is considered a valid instrument for documenting spatial distributions and temporal developments in order to support and advocate the advantages of Urban Green Spaces in future spatial planning.
Using salt diapirs and minibasins to constrain interpretations of crustal rifting and inversion in the Basque Pyrenees, Spain
Authors: Rowan Mark G , Muñoz Josep Anton , Roca Eduard , Ferrer Oriol , Carola Eloi , Garcia Iñaki
Published: March 2024

Published interpretations across the Basque Pyrenees vary significantly in their depictions of rifting and subsequent inversion. Major points of disagreement relate to: (i) the asymmetry of the margin, i.e., whether the major extensional and contractional detachment dipped toward the north or south; and (ii) the degree of decoupling between supra- and subsalt deformation and thus the amount of thin-skinned translation of the cover relative to basement. Here we use outcrop and subsurface data to analyze the salt structures along a regional transect in order to resolve this ongoing debate.Several aspects of the salt-related geometries are diagnostic of thin-skinned deformation. First, Villasana de Mena diapir has significantly thicker synrift strata on its basinward (northern) flank, contains stringers of Paleozoic rocks, and was growing passively during crustal extension. Its origin was consequently related to an underlying basement fault, yet it is situated today above an unfaulted detachment, suggesting that the diapir was translated above the salt during rifting and/or shortening. Second, Salinas de Rosio diapir is located at the southern termination of landward-shifting synrift depocenters and developed as a postrift to synorogenic salt pillow and then diapir. Thus, thin-skinned translation over a fault-related ramp in the base salt created synrift ramp-syncline basins, with the basement fault subsequently localizing salt inflation due to differential loading and then contractional buttressing. Third, Poza de la Sal diapir is at the basinward end of another set of synrift ramp-syncline basins and along a thin-skinned fold and thrust structure that was active during the synrift. Fourth, the large-scale geometry from the Bilbao Anticlinorium to the south documents contractional translation above a continuous salt detachment with a ramp-flat geometry.In summary, the salt and suprasalt geometries in a large part of the Basque Pyrenees demonstrate two phases of thin-skinned translation above a north-dipping salt detachment: (i) decoupled, basinward (northward) translation during rifting; and (ii) thin-skinned, southward-directed thrusting during inversion. The geometries are incompatible with thick-skinned inversion on a major south-dipping crustal detachment and smaller, basement-rooted faults that cut through the salt and its overburden.
Sensitivities of Marine Cloud Brightening Studied with a Lagrangian Cloud Model
Authors: Rowland Zachary Christopher , Hoffmann Fabian , Glassmeier Franziska , Steinke Isabelle , Russchenberg Herman
Published: March 2024

Marine cloud brightening (MCB) is a proposed climate engineering technique in which shallow liquid clouds are deliberately seeded with aerosol particles to increase their albedo and lifetime. Development of accurate models is essential to assess the feasibility of MCB; however, this is complicated by the large number of interacting microphysical processes that occur during cloud formation and the many environmental parameters that influence them. To simulate these microphysical processes in the required detail, a Lagrangian cloud model has been coupled to a simple adiabatic parcel model for this study.Using this modelling framework, a sensitivity analysis is performed to determine the susceptibility of MCB to the aerosol particle size distribution, meteorological conditions, and several cloud microphysical choices. Attention is paid to the effect of varying the number of giant cloud condensation nuclei (GCCN) in the aerosol distribution, as these are known to enhance precipitation, with potentially deleterious effects to MCB. The results of this analysis provide insight for understanding the susceptibility of cloud formation to environmental conditions and practical considerations for any possible future MCB implementation.
Ocean boundary pressures: Its significance and sensitivities
Authors: Styles Andrew , Boland Emma , Hughes Chris
Published: March 2024

The measurement and theoretical interpretation of circulations is often complicated by the abundance of eddies in the global ocean. However, when considering ocean pressure on the continental boundaries, the system of large-scale circulations can simplify drastically. As part of the OceanBound project, we demonstrate how this deliberately narrow view on the ocean can describe the fundamental aspects of ocean dynamics. Once the interpretative power of boundary pressures is established, we will present early results from an adjoint model (ECCO) to determine the remote and local physical processes which influence the boundary pressure signals. Adjoint models effectively run “backwards” as they relate ocean behaviours to physical causes in the past via automatic differentiation. If the final adjoint study can identify a manageable number of “control points” where specific forcing determines boundary pressures (therefore constraining global circulation) then this will help simplify conceptual models of the global ocean. Such a result would highlight the essential ocean processes for climate projections and produce a core vocabulary for interpreting ocean dynamics.
Paleozoic evolution in the Alborz: Continuous extension from the Gondwanan active margin to Paleotethys post-rift passive margin
Authors: Dolati Asghar , Smit Jeroen , Behrooz Amin , Jabbari Akbar , Shahidi Alireza
Published: March 2024

The transition from the Ediacaran-Cambrian Gondwana active margin to the rifting and opening of the Rheic and Paleotethys Oceans forms a turning point in the history of the Peri-Gondwanan Terranes. There are few better places to study the Pre-Cambrian and Paleozoic evolution of the northern Gondwana margin better than in the Central Iranian Microplate (CIM). The Alborz Mountains of northern Iran, formed by inversion of the Paleozoic Paleotethys passive margin of the Central Iranian Plate during successive collision phases since the Late Triassic, is one of the places where Paleozoic rocks are well exposed. The aim of this study is to elucidate the Paleozoic structural-tectonic framework and the transition of geodynamic regimes. We present the first paleostress analysis of the Paleozoic evolution of Alborz, were carried out for 49 sites, ranging from Cambrian to Permian outcrops in the Central and Eastern Alborz.We focus on the orientation of the pre-orogenic Paleotethys margin and the evolution of the Paleozoic stress field by inversion of fault slip data, starting with the Central and Eastern Alborz. Syn-sedimentary faults, i.e. those not reactivated by later tectonic events, were the main target of measurements for the paleostress analysis. Calculated paleostress tensors show a constant north-south extension stress regime throughout the Paleozoic during successive geodynamic regimes, from the Gondwana active margin to the Paleotethys post-rift passive margin. The extension was accommodated by east-west oriented (current reference frame), margin-parallel normal faults. These intra-formational faults are parallel to the main basin-bounding faults, which were repeatedly reactivated during later inversion and extension phases.
Nitrous oxide emissions from water bodies was a no-negligible contribution to nitrous oxide budgets in a subtropical forest catchment
Authors: Huang Tao , Lu Lingfeng
Published: March 2024

Inland water was considered an important sources of nitrous oxide (N2O) production and emissions. However, assessment of indirect emission factors (EF5r) and contribution of different water body N2O on N2O budgets remains challenging, and results are uncertain due to limited data availability. In this study, floated chamber and boundary layer model method were conducted on four diurnal days, and two year observations at high temporal resolution in a subtropical forest catchment in Southeast China. The results showed that there was clearly diurnal characteristics of N2O emissions, and the CC98 model was more fit for estimating stream N2O emissions. The N2O fluxes from different water body was in the order: ponds (35.99±33.58 μg m-2 h-1) > main stream (17.09±4.48 μg m-2 h-1)> tributary (14.78±12.79 μg m-2 h-1). All of their EF5r (0.050%±0.058% to 0.249%±0.456%) were significantly higher than the IPCC 2006 default value 0.025%, suggesting that N2O emissions from China and world inland water may be grossly underestimated. Multiple regression model selected the dissolved oxygen and NH4-N concentrations as the crucial factors influencing the N2O emission fluxes from streams, whereas dissolved oxygen and NO3-N in ponds. Although the water body's surface area only occupied 2% in this catchment, where the N2O emissions fluxes were approximately contribute 1.4% of N2O budget in whole catchment. These findings will draw attentions to the role of inland water N2O productions and emissions in the contributions of N2O budgets, especially in the large scale N2O estimated.
Resilience of the AMOC
Authors: Jacques-Dumas Valérian , Kühn Christian , Dijkstra Henk A.
Published: March 2024

The Atlantic Meridional Overturning Circulation (AMOC) is a crucial part of the climate system that carries warm and saline water towards the northern Atlantic and is an important component in the global meridional heat transport. However, the AMOC is a so-called “tipping element”: there is observational evidence that it is in a bistable regime and may thus collapse under anthropogenic greenhouse gas emissions. Bi-stability has also been found in a hierarchy of models, from a simple two-box model up to a CMIP5 global climate model (CESM1). Considering a possible upcoming tipping, it is critical to assess how likely the AMOC is to undergo a collapse under different greenhouse gas forcing scenarios.  This issue is tightly related to the notion of resilience, which refers to the ability of a system to sustain a certain forcing while remaining in its original state or to return to its original state after being displaced.Studying the resilience of the AMOC requires to observe its collapse, which is very difficult due to its rarity, especially in very complex models. That is why we use a rare-event algorithm called Transition-Adaptive Multilevel Splitting (TAMS). Given a certain definition of the current-day and collapsed AMOC, TAMS pushes trajectories in the direction of a collapse at a much lower cost than Monte-Carlo simulations. This method outputs typical collapse trajectories starting from a present-day AMOC, under a certain chosen hosing flux. This process is repeated for a wide range of freshwater forcings. From those trajectories, we extract observables (e.g. the AMOC strength), which are scalar functions that are interpreted as resilience observables. By monitoring these observables, we can rank different climate change scenarios depending on the risks they impose on the AMOC. Moreover, we relate these observables to existing mathematical definitions of resilience. Finally, we determine which observables are best suited to describe the resilience of the  AMOC, with a focus on those that can be measured in the field.
The critical importance of Wilkes Land Subglacial Basin stability (East Antarctica)
Authors: Colleoni Florence , De Santis Laura , Barruol Guilhem , Dutrieux Pierre
Published: March 2024

While most of West Antarctic ice shelves are thinning due to ongoing oceanic warming, East Antarctic ice shelves, except a few ones, are apparently more stable. One sector in particular, the Wilkes Subglacial Basin, is not showing any or very little sign of weakness to ongoing climate change. This sector of Antarctica is drained by the Cook ice shelf, the Ninnis ice shelf and the Mertz ice tongue. Those ice shelves have experienced some observed calving events in the past decades, but actual ice flow does not indicate that this sector is retreating and contributing to global mean sea level rise. But can we really measure the sensitivity of a sector only accounting for two decades of observations? Geological archives and morphological evidence of the George V Land continental margin in front of those glaciers suggest, on the contrary, that the ice sheet over the WSB has been one of the most active of East Antarctic sectors through its glaciological history. A multi-year sea ice cover, reducing only under exceptional atmospheric conditions, does not allow the systematic exploration of the area.  Rare geophysical, glaciological, oceanographical, geological and geographical hampers a proper assessment of the instability potential of this area. International cooperation not only is needed to reach and operate in such difficult sector of Antarctica, both at land and on sea, but is also needed to perform multi-disciplinary measurements.
Water Availability Assessment in the Upper Colorado River Basin
Authors: Miller Matthew , Day Natalie , Dickinson Jesse , Engott John , Jones Casey , Knight Jacob , Longley Patrick , Lopez Samuel , Masbruch Melissa , McDonnell Morgan , Miller Olivia , Schmadel Noah , Tillman Fred , Wise Daniel
Published: March 2024

The lack of comprehensive water supply prediction capacity in most areas of the U.S. poses challenges in evaluating water availability. In order to improve water availability prediction and assessment, in 2019, the U.S. Geological Survey initiated planning efforts to intensively study five medium-sized basins throughout the U.S. over the next decade, including the Upper Colorado River Basin (UCOL). Research in the UCOL aims to provide insight into how past, present, and future snow conditions – including amount, timing, melt, and transitions from snow- to rain-dominated systems – impact water supply (quantity and quality) and the ability to meet demand. A specific emphasis is placed on how these processes affect water budget components and dissolved solids concentration and loading in the UCOL. A fully integrated groundwater-surface water hydrologic model (GSFLOW), and temporally dynamic dissolved solids models (SPARROW) that explicitly represent the groundwater contribution to dissolved solids loading to streams are being applied to meet the study objective. Comprehensive information on water diversion and groundwater pumping has been compiled and is being explicitly represented in the models to better represent human demand.  Temporal and spatial patterns in predicted water quantity and quality conditions are being evaluated in the context of past and projected future changes, summarized over 30-year time periods, in snow metrics.  Historical trends in multiple snow metrics, water budget components, groundwater levels, and dissolved solids provide context for evaluations of current conditions and motivation for further investigation and modeling. The tools and concepts developed in the UCOL will contribute to ongoing work in the other regional study basins as well as a forthcoming national water availability assessment. 
Evaluating and improving cesium-137 technology for estimating soil redistribution using soil loss data measured during 1954-2015
Authors: Zhang X.C. John
Published: March 2024

Soil erosion causes worldwide land degradation. Long term monitoring of soil erosion is costly and labor intensive. Multiple models using Cs-137 fallout from atomic bomb tests are developed to retrospectively estimate average soil erosion since 1954. However, those models have not been rigorously validated due to the lack of compatible long-term measured soil loss data and thus their usefulness has been seriously challenged. Using 70 years of rare soil loss data measured in two small watersheds of
Closing the data gap to develop Land Surface Models for Congo Basin forests
Authors: Hubau Wannes ,   DAMOCO, PILOTMAB & CANOPI consortium
Published: March 2024

Congo Basin forests are among the most diverse, carbon-rich and CO2-absorbing areas in the World (1,2) and play an increasingly important role in international climate policy (3). On the pivotal CoP26 in Glasgow, more than 100 World leaders promised to stop deforestation by 2030, including specific pledges to focus on protecting Congo Basin forests. However, there is a striking discrepancy between the Congo Basin’s paramount importance versus its poor scientific coverage (4). As a result of this data gap, Earth System Models are not capturing present-day tropical forest carbon dynamics (5). Therefore, our consortium is contributing to closing the Congo Basin forest data gap and improve Land Surface Models to capture its biodiversity and carbon dynamics. To reach this ambition, we are collecting field data on permanent forest inventory plots scattered across the Congo basin.The data covers multiple time scales by combining different methodological approaches: (i) weakly monitoring of cambial and foliar phenology of selected trees in the plots provides seasonal- and annual-scale changes in carbon uptake, (ii) repeated tree diameter and height measurements of all trees in the plots reveal decadal-scale changes in the carbon balance and tree community composition, (iii) measuring whole-tree, wood and leaf traits on selected trees in the plots allow in-depth analysis of decadal-scale changes in taxonomic and functional composition, (iv) identification of radiocarbon dated soil charcoal sampled in the plots reveal century-scale and millennial-scale changes in biodiversity, (v) continuous monitoring of climate variables provides yearly and decadal-scale changes in temperature and water availability.By themselves, those data shed light on the short- and long-term resilience of critical Congo Basin forest ecosystem functions. Here we present an overview of recently published and preliminary results showing how our consortium contributes to advance our understanding of the effects of environmental change on vegetation dynamics, tree mortality and carbon dynamics of Congo Basin forests. Combining all these collected field data will ultimately allow to parameterize and validate Land Surface Models specifically for the Congo Basin.1.Hubau, W. et al. Nature 579, 80–87 (2020). 2. Jung, M. et al. Nat. Ecol. Evol. 5, 1499–1509 (2021). 3. Rockström, J. et al. PNAS 118, 1–5 (2021). 4. White, L. J. T. et al. Nature 598, 411–414 (2021). 5. Koch, A., Hubau, W. & Lewis, S. L. Earth’s Future. 9, 1–19 (2021).
Humid, warm and treed ecosystems show longer time-lag of vegetation response to climate
Authors: Gao Xinran , Gonsamo Alemu , Zhuo Wen
Published: March 2024

Climate-induced temperature rise and shifting precipitation patterns across diverse global ecosystems impact vegetation growth. Due to the diverse nature of terrestrial ecosystems and their climates, interactions between climate and vegetation vary spatially and temporally. Most studies focus on simultaneous interactions, overlooking the legacy effects of climate on vegetation physiology and growth. In this research, we use satellite-observed Solar-Induced Fluorescence (SIF) and Enhanced Vegetation Index (EVI) as the indicators of vegetation photosynthesis and greenness to assess the time-lag effect in vegetation response to climate from May 2018 to Dec 2021. Specifically, we examine the relationship between SIF, EVI, and concurrent or antecedent climate variables containing precipitation, soil moisture, and temperature. Additionally, we compare different time-lags of these climate variables under distinct environmental conditions to understand how climatic conditions influence them. Our findings reveal that arid and cold climates exhibit more concurrent climate-vegetation interactions than other ecosystems. In contrast, humid ecosystems with high mean annual temperature and precipitation show a substantial time-lag response of vegetation to climate, for up to six months. Given the significance of time-lag effects in global climate-vegetation interactions, acknowledging these effects is paramount for improving our understanding of vegetation dynamics in a changing climate.
Causal effects of teleconnection patterns on soil moisture through different climate paths over the Greater Horn of Africa
Authors: Zhuo Wen , Fang Shibo , Gao Xinran , Lourenco Ricardo B. , Yu Yanru , Han Jiahao , Gonsamo Alemu
Published: March 2024

Soil moisture is undoubtably a vital variable of the climate system. Understanding the interactions among atmosphere, climate, and soil is necessary for water resource management, drought monitoring, and disaster prevention. However, evaluation of those interactions so far primarily focused on typical correlation analysis which often fail to imply causal relationship due to autocorrelation and high dimensionality within time series variables. Here, we used a data driven causal inference method called PCMCI+ to discover causal relationships among teleconnection patterns (El Niño Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD)), climate variables (precipitation and temperature) and soil moisture during 1980-2022 over Great Horn of Africa (GHOA), where is a susceptible region to suffer from severe drought. Further, we quantitative calculated the causal effects of teleconnection patterns on SM through different climate paths. Results suggest that IOD generally presents higher causal effects on climate variables (temperature and precipitation) or on soil moisture through both precipitation and temperature paths than ENSO over most parts of GHOA. Moreover, precipitation performs shorter lag effect and greater causal effect on soil moisture in GHOA. Our study provides the first attempt to quantitatively analyze the causal effects of teleconnection patterns on SM through both precipitation path and temperature path, and it highlights the causal relationships within atmosphere-climate-soil interactions, which could help for better understanding of climate change impact on drought over GHOA.
Investigating Changes in Tropical Cyclone Inner Core and Outer Rainband Precipitation in Models under Warming Scenarios
Authors: Stansfield Alyssa , Rasmussen Kristen
Published: March 2024

Extreme precipitation from tropical cyclones (TCs) commonly results in fatalities and expensive property damage in both coastal locations and hundreds of miles inland. Recent studies have found a decreasing trend in TC inner core precipitation and an increasing trend in outer rainband precipitation using about 20 years of precipitation data from satellite products. Most modeling studies that have looked at the response of TC precipitation to climate change found either an increase in the inner core only or an increase in both the inner core and outer rainbands; however, the models were too coarse to resolve detailed TC precipitation structures. This work uses high-resolution Weather Research and Forecasting (WRF) simulations to explore how three-dimensional TC convective structures and precipitation respond to both idealized and more realistic warming scenarios. TCs in the idealized simulations show increasing precipitation in both the TC inner core and outer rainbands with warmer SST, in disagreement with the decrease in inner core precipitation over time in observations. This suggests that either these model simulations are too idealized to simulate the observed decrease in inner core precipitation or the models are missing a key physical process happening in real-world TCs. It also suggests that the disagreements between TC precipitation trends with warming in models and satellite observations are not caused by insufficient model resolution. Results from these idealized simulations will be compared to TCs in 20-year-long historical and future climate runs in regional WRF.
Development of counterscarps by flexural toppling of schist in the Bedretto valley, Swiss Alps
Authors: Chigira Masahiro , Kojima Satoru , Pedrazzini Andrea , Li Fei , Jaboyedoff Michel
Published: March 2024

We investigated the geological structure and the development of DGSD in the south side of the Bedretto Valley, Swiss Alps by field survey, topographic analysis, trenching, and 14C dating.The Bedretto valley has major slope breaks approximately 300 m above the current valley bottom, which separate the area into two domains. Above the slope breaks, and in the catchments of the tributaries of the Bedretto valley, large flexural toppling occurs with counterscarps and troughs on two ridges between tributaries. Their hinges expose on the side of each ridge to suggest that the flexural toppling reaches to the depth of 200 m. The two large flexural toppling accompanied settling down of a wedge-shaped ridge top, which is bounded by two face-to-face normal faults. Below the slope breaks and on the side slopes of Bedretto valley, smaller but sharper counterscarps and terraces, which are of the incipient stage of counterscarps, develop. These counterscarps and troughs appeared by the preferential shearing along tectonic faults, which are pervasive in the area with a ~30 m average spacing. They are nearly parallel to the steeply-dipping schistosity; the faults may originate as lateral faults but reactivated as normal gravitational faults.Deformation of the trenched sediments suggests that the flexural toppling occurred intermittently along a fault during three events, in which the first event had the largest dip slip of 30 m, much larger than the displacements of the subsequent events.The third event at least was probably induced by an earthquake shaking, which is strongly suggested by the injection of fault gouge into the overlying sediments in the trough. Such injection should have been caused by pore pressure build up during earthquake shaking.
Permafrost stability in and around three North Slope Borough communities in Alaska
Authors: Romanovsky Vladimir , Nicolsky Dmitry , Farquharson Louise , Rybakov Sergei , Wright Thomas
Published: March 2024

The impact of climate warming on permafrost and the potential of climate feedback resulting from permafrost thawing have recently received remarkable attention. Climate warming promotes an increase in permafrost temperature and active layer thickness, which, in turn, affect the stability of northern ecosystems, threaten infrastructure, and cause the release of carbon dioxide and methane into the atmosphere. The timing and the rate of permafrost degradation are two of the major factors in determining the anticipated negative impacts of climate warming on the Arctic ecosystems and infrastructure. The results of permafrost and active layer temperature observations (from the ground surface down to 1.5 m) at the three North Slope Borough communities of Point Lay, Wainwright, and Utqiagvik will be presented in this paper. Ground temperatures were measured both in natural conditions around the villages and under residential and commercial buildings to estimate the impact of infrastructure on permafrost stability. Generally, for all three villages, permafrost is still thermally stable. The mean annual ground temperature at 1.5-m depth is typically below -4°C for both natural conditions and under the elevated above ground engineering structures. One of the exceptions is thermokarst depressions such as deep troughs or ponds filled with water within and outside of the village of Point Lay. The mean annual water temperature at the bottom of some of these ponds with the water depth more than 0.5 m approaches the 0°C threshold, and in some cases even exceeds it, which can trigger development of a talik under these depressions. This may accelerate permafrost degradation at these locations with certain negative consequences for the stability of the village infrastructure and may manifest in numerous hazards for the residents. The methods of stabilization of permafrost and mitigation of adverse impacts of permafrost degradation will be discussed in this presentation. To enhance our understanding of possible future rates and pathways of permafrost degradation and to predict the consequences to residents, accurate high spatial resolution permafrost models are needed. Establishment of these models is possible only by integrating available high-resolution environmental data and by the assimilation of existing field and remote sensing data and observations into these models. The use of high-resolution (30x30 m) stand-alone permafrost dynamics GIPL2 model will be discussed to illustrate how changes in climate and further development of infrastructure will affect permafrost and people in this area.
Remote sensing of trace gases from multiple Chinese satellite instruments and its application combined with AI 
Authors: Liu Cheng , Wang Xiaohan , Xue Jingkai , Hu Qihou , Li Qihua , Su Wenjing , Zhang Chengxin
Published: March 2024

Recently, China launched a series of the Environmental Trace Gases Monitoring Instruments (EMI) on satellites with different over-pass times to support global daily multi-temporal atmospheric monitoring. Compared with previous satellites in sun-synchronous orbit, such as OMI and TROPOMI which over passes at 13:30 LT, the series of Chinese EMI satellite instruments with similar performance can be used to investigate the diurnal variations in trace gases. Besides, the series of EMI expanded the areas with diurnal observation in trace gases from the North America, East Asia, and Europe, where are covered by geostationary satellite observations, to the global scales, particularly the South Hemisphere. However, how to eliminate the systematic bias between retrieval results from multiple satellites is the major difficulty.Here we are performed further spectral calibration and inversion algorithm improvement. We use meteorological parameters and a priori atmospheric profiles at different moments in the radiative transfer calculations and inversion. Results from the Tracer Model (version 5, TM5) were also used for background correction. We use secondary radiometric calibrations, i.e. soft calibrations, to further correct the systematic biases between observed spectra from different instruments. Through these algorithm updates, we have successfully retrieved the concentrations of several trace gases, such as Ozone (O3), nitrogen dioxide (NO2), sulfur dioxide (SO2) and formaldehyde (HCHO), at different times of day (10:30 and 13:00 LT). The retrieved trace gas concentrations from the series of EMI were further used to investigate the diurnal variation in air pollutant emissions and ozone formation.Moreover, due to the influence of factors such as cloud cover, satellite observations often have gaps. Here we used artificial intelligence (AI) analysis, such as neural operator methods, to achieve spatial full coverage of remote sensing results. We masked existing satellite observation data, and then used artificial intelligence models to repair and fill in missing areas, with ERA5 meteorological field data, various emission inventories, and geographical information data. The combination with AI analysis improved the usability and application scope of satellite data.
Tracking permafrost thaw using iron as a geochemical tracer for climate change
Authors: Barker Amanda , Baxter William , Barbato Robyn , Sullivan Taylor , Douglas Thomas
Published: March 2024

Arctic ecosystems are changing as a result of climate warming, altering soil thermal and moisture regimes and contributing to permafrost thaw, which impacts the biogeochemistry of terrestrial and aquatic environments. This occurs across broad scales of space and time. Assessing how and to what extent thawing permafrost impacts soils, sediments, and aquatic environments is integral to constraining greenhouse gas emission estimates, microbial diversity, vegetation succession, and water quality, but quantifications remain difficult to assess on a landscape-scale. When top-down thaw of near-surface permafrost occurs porewaters infiltrate deeper and expose fresh, previously frozen material. This input of oxygenated water greatly alters the oxidation/reduction (redox) conditions, which are intricately tied to soil moisture/temperature, ionic strength, and play a critical role in carbon release. Using optical sensors, satellite and unmanned aerial surveys, and bulk- and micro-scale analytical techniques, we present a comprehensive approach for tracking iron concentrations and redox conditions in permafrost regimes in the Arctic. Overall, we found evidence that iron (Fe) and to a lesser extent manganese (Mn) could be useful as geochemical indicators of permafrost thaw and release of Fe(II) from thawing permafrost and further oxidation to Fe(III) could translate to a higher degree of seasonal rusting coinciding with the warming and thawing of near surface-permafrost.
Early evaluation of effects on Dual-frequency Precipitation Radar observations by the orbit boost of the GPM Core Observatory 
Authors: Kubota Takuji , Masaki Takeshi , Kikuchi Gennosuke , Ito Masato , Higashiuwatoko Tomohiko , Kanemaru Kaya , Takahashi Nobuhiro , Yamamoto Kosuke , Furukawa Kinji , Nio Tomomi
Published: March 2024

The NASA and the JAXA performed orbit boost maneuvers in November 2023 that raised an altitude of the Global Precipitation Measurement (GPM) Core Observatory from 400 km to 435 km to extend its lifetime. Effects of the orbit boost on the spaceborne precipitation radar have been investigated in the Tropical Rainfall Measuring Mission (TRMM) performed in August 2001. This study evaluates effects on DPR observations due to the GPM orbit boost.Firstly, spacecraft altitudes of the GPM Core Observatory were analyzed during the period from 13rd October to 17th November 2023. The minimum altitudes were changed from about 400 km to about 435 km by the orbit boost. The averaged altitudes were changed from about 407 km to about 442 km by it. Thus, 407km and 442km were adopted as typical averaged satellite altitudes in pre-boost and the post-boost, respectively.Spatial resolution at the nadir and swath width is changed at 5.04km×5.04km and 255.8 km at satellite altitude of 407 km to 5.48km×5.48km and 277.9 km at satellite altitude of 442 km, respectively.  Distances between adjacent footprints in the cross-track direction between the pre-boost and the post-boost using observation data and they confirmed that changes of the sampling were larger in the cross-track direction (about 5 km to 5.5 km at the nadir).It was found that the DPR coverage tendency was changed by the GPM orbit boost. In pre-boost, DPR achieved 100% coverage in 8 days. On the other hand, with post-boost, the coverage was still 99.9834% after 24 days, slightly less than 100%. This coverage trend is expected to change with satellite maneuvers. The maneuver is expected to change the orbit elements, thereby covering all locations.The sensitivity degradation of the DPR is expected owing to the increase of satellite altitude. Measured radar reflectivity factor (Zm) at storm top height (STH) over the ocean for is used as an indicator of the sensitivity. With analyzing Zm at STH over the ocean, the sensitivity degradation was found for about 0.8-0.9dB for KuPR, and about 0.7-0.9dB for KaPR.
High resolution Sentinel-2 data-based ecological and biophysical variables analysis in Indian part of Sundarban Mangrove Forest
Authors: Al-Ramadan Baqer , Halder Bijay , Yaseen Zaher Mundher , Juneng Liew
Published: March 2024

Mangrove forests are important in Indian Sundarban Biosphere Research (SBR) for coastal hazards and vulnerability reduction. Recent extreme natural disasters like flood inundation, cyclonic effects, shoreline change, and river bank erosion are the main threatening phenomena for coastal livelihood and forest cover change. Mangrove forest is not only a shelter for human life but also important for animals and gradually forest degradation triggers their life in serious issues. Technologies can assist in reducing those serious issues through space-based analysis, and adaptation policies and give them a sustainable life. Current space-based technologies can be applied for forest cover change analysis in the SBR area. This analysis investigates the forest cover in different years (2018 and 2022) through Sentinel-2 data. Various biophysical and ecological variables are measured because of recent cyclonic effects that have gradually affected this region. Some recent cyclones like Titli (2018), Fani (2019), Bulbul (2019), Amphan (2020), and Yass (2021) gradually triggered coastal geomorphology change, shoreline shifting, river bank erosion, and mangrove forest losses. Sentinel 2 data is applied in ArcGIS v10.8 and SNAP v9.0 for calculating those outcomes. The highest NDVI values are observed at 0.72 (2018) and 0.53 (2022), while the highest TNDVI values are also remarkable observations like 1.11 (2018) and 1.02 (2022) respectively. During cyclonic effects, those regions are affected by flood inundation, increased soil salinity, bank erosion, and huge economic losses observed. Similarly, high SAVI values are 1.08 (2018) and 0.81 (2022). The forest areas mainly decrease in G-plot, L block, some parts of Kultali block, and Jambu Dweep areas, while Blacky Island, HaLF-FiSH Island, and near Kakdwip block have increased mangrove forest areas. The high NDSI values observed were 0.42 (2018) and 0.49 (2022) because of saltwater intrusion which is triggering the crop dynamics and production losses in those regions. The S2REP and IRECI, both chlorophyll estimation indices indicate that the forest cover areas are lost during the study periods. The forest degradation index (FDI) values and threshold-based forest health index are also warned for adopting those regions, otherwise, the mangrove environment is gradually destroyed by natural extreme events and some man-made activities. Mangrove forest protection is essential for the planners, policy-makers, and stakeholders for safe forest life as well as coastal environment and coastal livelihood. Some adaptation strategies like cyclone shelters, mangrove plantations, early warning systems, river bank erosion reduction, and awareness can help to reduce the risk of extreme natural hazard events.