bluuebunny/crossref_metadata_2025 huggingface dataset:
The performance of scientific, indigenous, and hybrid weather forecasts: Systematic evaluation and farmers’ perception in Bangladesh
Authors: Sutanto Samuel , Paparrizos Spyridon , Kumar Uthpal , Datta2 Dilip , Ludwig Fulco
Published: February 2023

Access to reliable and skillful weather information could assist smallholder farmers in Bangladesh to reduce their vulnerability to rainfall variability and extremes. The available weather forecast information, however, is still limited in the provision of daily location-specific weather information for smallholder farmers in Bangladesh. Because of this reason, the use of local forecasts is a more favorable and affordable way of accessing weather information for many farmers in low-latitude developing countries. In the WATERAPPscale project, we have initiated a climate information service that provides timely and location-specific weather forecasts for smallholders and established 16 farmer’s weather schools across Bangladesh, where training on interpretation of scientific forecasts (SF), collection of local forecasts (LF) data, and sharing forecast information took place. This study aims to systematically evaluate the performance of the SF and LF used by farmers, by applying a dichotomous method to distinguish yes/no rainfall events. The results were compared with farmers’ perception of the forecast skills. In addition, the skill of a simple hybrid forecast (HF), which is an integrated system of SF and LF, was assessed. The SF and LF data were obtained from the meteoblue hindcast and from the questionnaires, respectively. This study used ERA5 and ground observation datasets as benchmarks for the weather forecasts. Results show that overall, the LF has slightly higher skill than the SF when compared to the ERA5 dataset. The forecast performance, however, reduces by almost half when the ground-based observation is used instead of ERA5, associated with a high false alarm. The evaluation results, however, are contradictory to the farmers’ perception that SF has a much higher performance than LF. Combining the SF and LF into a simple HF generates higher skill than any single forecast alone, which highlights the necessity to develop a hybrid forecast that combines scientific and indigenous weather forecasting for farm decision-making. The developed HF system will deliver a reliable forecast, trustworthy, and conserved indigenous knowledge that has been passed down from generation to generation.   
Modeling lunar magmas in the Artemis Era
Authors: Iacovino Kayla , Prissel Kelsey
Published: February 2023

As the planetary science community sets its sights on the Moon, the existence of an open-source, up-to-date, and user-friendly modeling tool for lunar rocks is critical to maximizing the scientific return of ongoing and upcoming lunar missions (e.g., Artemis, PRISM, CLPS). While the creation of new code from the ground up is an important aspect of modern computational petrology, here we advocate for the modernization of legacy code, the results of which dominate the literature and shape our current understanding of geologic processes across multiple scales. Modernization of legacy code is critical as it enables the community to put new model results in the context of modern consensus gentium. Here we discuss how modern best practices for code development, publishing, and maintenance should be applied to upgrading legacy code, using lunar petrologic models as an example. We highlight critical gaps in our ability to model lunar processes that could be filled simply with updated modeling tools (i.e., where underlying experimental and analytical data already exist but are not incorporated into existing modeling tools).Current modeling tools developed specifically for lunar compositions are sparse and can contain outdated parameterizations. One critical knowledge gap is our ability to model silicic lunar magmas, which are evidenced in nature by felsic fragments in returned Apollo samples and silica-rich volcanic domes identified on the borders of lunar mare by remote sensing. The most popular tool for modeling lunar magmas is MAGPOX, born from a series of FORTRAN scripts and ported to MATLAB, which is underpinned by an exclusively basaltic database. MAGPOX requires the crystallization of olivine on the liquidus, and thus has limited application to the full compositional diversity of lunar magmas. rhyolite-MELTS has been used to model silicic magmatism on the Moon, but its use typically requires additional experimental work given that the MELTS database is biased towards terrestrial rocks with lower FeO, higher alkalis, and higher fO2 than lunar rocks. Notably, the MELTS database includes the same published basaltic lunar rocks used in MAGPOX regressions and so should be trustworthy for silica-poor lunar magmas. Still, the adoption of MELTS by the lunar community requires extensive testing against MAGPOX, PERPLE_X, and large lunar experimental databases.Before we can even begin to update the parameterizations underpinning MAGPOX or efficiently compare MAGPOX to other models, a modern code library is required to perform adequate testing and benchmarking. In this talk we will explore the state of lunar petrologic modeling, what can be done now, and how we can best bring it into the 21st century.
Soil moisture simulation at the local scale using satellite remote sensing data towards sustainable irrigation
Authors: Moradi Shirin , Mengen David , Vereecken Harry , Montzka Carsten
Published: February 2023

Water plays a crucial role in food security. Currently, agriculture irrigation withdraws about 70% of the world’s fresh water. By 2050, the world population is estimated to increase to over 9 billion (UNDP, 2022). Together with climate change that is increasingly affecting the terrestrial ecosystem such as increasing the temperature, drought and extreme flood, all of which can lead to crop failure (IPCC et al., 2007) and water scarcity, the demand for food and irrigation water is expected to rise, dramatically. Accordingly, novel technologies for innovative, real-time water management for sustainable irrigation are necessary. In this regard, the main objective of this study is to simulate and predict the soil water content at the root zone, as a main factor of defining the irrigation time and quantity. Here, we have chosen a study area of 150km2 which is located in west Europe, covering parts of Netherlands, Belgium, Luxemburg and west of Germany. Therewith, we have relied on the coupled land surface-subsurface CLM-Parflow model for hydrological simulations and the soil moisture data from on-site Cosmic-ray neutron sensor (CRNS) stations, as well as the SMAP (L3_SM_E_P), and high resolution C- and L-band Synthetic Aperture Radar (SAR) are used for data assessment. It is expected that the reliability of the soil moisture magnitude and dynamic will be examined.
Deep learning based identification of carbonate rock components in core images
Authors: Dawson Harriet , John Cédric
Published: February 2023

Identification of constituent grains in carbonate rocks is primarily a qualitative skill requiring specialist experience. A carbonate sedimentologist must be able to distinguish between various grains of different ages, preserved in differing alteration stages, and cut in random orientations across core sections. Recent studies have demonstrated the effectiveness of machine learning in classifying lithofacies from thin section, core and seismic images, with faster analysis times and reduction of natural biases.  In this study, we explore the application and limitations of convolutional neural network (CNN) based object detection frameworks to identify and quantify multiple types of carbonate grains within close-up core images. Nearly 400 images of carbonate cores we compiled of high-resolution core images from three ODP and IODP expeditions. Over 9,000 individual carbonate components of 11 different classes were manually labelled from this dataset. Using transfer learning, we evaluate one-stage (YOLO v3) and two-stage (Faster R-CNN) detectors under different feature extractors (Darknet and Inception-ResNet-v2). Despite the current popularity of one-stage detectors, our results show Faster R-CNN with Inception-ResNet-v2 backbone provides the most robust performance, achieving nearly 0.8 mean average precision (mAP). Furthermore, we extend the approach by deploying the trained model to ODP Leg 194 Sites 1196 and 1190, developing a performance comparison with human interpretation. 
Cratonic Lithosphere Delamination and Relamination Explain the Temporal Variation of Cratons
Authors: Peng Lihang , Liu Lijun , Liu Liang
Published: February 2023

Cratonic lithosphere delamination has been frequently suggested in recent studies. However, the fate of the delaminated Sub-Cratonic Lithospheric Mantle (SCLM) has not been thoroughly investigated. Here, we use 2D numerical models to study the evolution of initially delaminated SCLM whose density is initially larger than that of the ambient mantle. Our simulations reveal that after the dense lithospheric segments sink into the hot mantle, the increase of thermal buoyancy and/or removal of the dense components reverse their trajectory, and most of these segments eventually relaminate to the base of the above lithosphere. The time needed for the relamination process to complete is 100-300 Myr since initial delamination, with the exact value depending on the buoyancy of the SCLM and the mantle viscosity. Both delamination and relamination could generate a rapid hundred-meter to kilometer scale surface uplift. After the relamination, the subsequent cooling of the SCLM causes gradual subsidence by ~2 km. This model provides a novel explanation for the observed Phanerozoic vertical motion of many cratons as well as the origin of the enigmatic intracratonic basins, arches, and domes in the upper cratonic crust. According to our models, the delamination-to-relamination evolution mode could occur repeatedly during the past one billion years, as could reconcile the apparent long-term intactness of cratonic crusts and the temporal variations of cratonic topography.
Efficiency of dietary sustainability and its global transition
Authors: He Pan , Liu Zhu , Hubacek Klaus , Baiocchi Giovanni , Guan Dabo
Published: February 2023

Global diets consume tremendous natural resources while causing multiple environmental and health issues. As the world faces challenges of adequate nutrition security with concomitant climate and environmental crises requiring urgent action, policies need to improve the efficiency of devoting environmental input of the food systems for health benefits. Here we evaluate the global transition of such efficiency in the past two decades represented by health benefits obtained by per unit of 4 key environmental inputs (GHG emissions, stress-weighted water withdrawal, acidifying emissions, and eutrophying emissions) in 195 countries. We find that the efficiency of each environmental input follows an N-shaped curve along the Socio-Demographic Index (SDI) gradient representing different development levels. The efficiency first increases by benefiting from the eliminated stunting with a larger abundance of food supply, then decreases driven by climbing environmental impacts from a shift to animal products, and finally starts to slowly grow again as countries shift toward a healthier diet. Our efficiency indicator offers an improved understanding of nutritional transitions in terms of environmental impacts and a useful way to monitor the transition of dietary patterns, set up policy targets, and evaluate the effectiveness of specific interventions.
Coupling simple dry physics to a dynamically adaptive global atmosphere model
Authors: Kevlahan Nicholas , Ching-Johnson Gabrielle , Dubos Thomas
Published: February 2023

Adaptive global circulation models (GCMs) have the potential to significantly improve the computational efficiency and accuracy of climate simulations by dynamically adjusting the local grid resolution to ensure a specified numerical tolerance or to track features of interest.  We have developed the global dynamical cores WAVETRISK-ATMOSPHERE and WAVETRISK-OCEAN to explore the strengths and weaknesses of dynamical GCMs. The main open challenge of adaptive climate modelling is how to appropriately couple the dynamical core to the physics. The physics should ideally be “scale-aware”: adjusting the parameterization as necessary based on the current local resolution (or disabling it entirely if the physical phenomenon becomes fully resolved).  A related question is whether the grid adaptation criteria should be based on the physics as well as the dynamics. Such scale-aware physics parameterizations remain poorly understood.  In this talk we report on initial progress in coupling WAVETRISK-ATMOSPHERE to Hourdin’s (1992) “simple dry physics”.A better understanding of scale-aware physics will also improve non-adaptive climate modelling, since such models currently require extensive tuning each time the resolution is increased. An additional goal of this project is to develop a set of test cases for the simple physics that could be used to compare dynamical cores using a well-understood and standardized physics package.This is joint work with Gabrielle Ching-Johnson (MSc student, McMaster University, Canada) and Thomas Dubos (LMD, École Polytechnique, France)
Hydrothermal breccias in banded iron formations from the Isua Supracrustal Belt, Southwest Greenland
Authors: Nichols Claire , Halwa Stephanie , Robinson Stuart
Published: February 2023

Eoarchean (3.7 Ga) banded iron formations (BIFs) from the Isua Supracrustal Belt, Southwest Greenland have been variably metamorphosed and deformed.  At the top of the northeastern extent of the belt, the lowest degree of metamorphism is observed with a maximum pressure and temperature of 1.5 – 4 kbar and 360 – 400 °C, respectively.  Previously, the banding in these BIFs has been interpreted as entirely tectono-metamorphic in origin3.  However, in the best preserved regions in the northeastern part of the belt the BIFs are exceptionally well preserved, and exhibit potentially sedimentary features including possible way-up indicators. A particularly striking features of the BIFs in the northernmost region are repetitive bands of brecciated material which are approximately 30 cm wide and occur every 1 – 2 m.  Similar brecciation textures are observed in dolomites in the area which have previously been interpreted as tempestites (storm-wave breccias) and evidence for a shallow marine environment.  The occurrence of similar breccias in the BIFs is at odds with the interpretation that these deposits formed in relatively deep water.  The aim of this study is to interrogate the origin of the brecciated layers in the BIF, and whether these layers represent primary depositional ‘beds’ or were formed by later metamorphism and fluid alteration. Petrographic observations show that the brecciated layers contain extensive carbonates, while the surrounding BIF is dominated by alternating layers of magnetite and chert. This is consistent with the contrast in weathering between the brecciated layers and banded layers from field observations.  The origin of the carbonates is investigated by examining their δ13C and δ18O isotope and rare-earth element compositions.  Preliminary results indicate that the breccias are hydrothermal in origin.  We use these observations, in combination with paleomagnetic field tests to argue for some degree of preservation of primary depositional features in the Isua BIF.
Analysis of extreme precipitation in Bangladesh based on reanalysis data and climate models
Authors: Huang Yuwei
Published: February 2023

Understanding extreme precipitation is essential for mitigating the associated risk. This study analysed eight Coupled Model Inter-comparison Project phase 6 (CMIP6) models by capturing daily, seasonal, yearly, and extreme precipitation over Bangladesh during the period 1961-2014, treating ECMWF Reanalysis v5 (ERA5) rainfall reanalysis data as an observational reference. Sixteen extreme precipitation definitions were found in the literature, implemented, and used in a comparative analysis in Bangladesh, one of the most vulnerable countries to climate change. Definitions used in the literature, duration definitions, such as the Consecutive Dry Days (CDD) and the Consecutive Wet Days (CWD), frequency definitions, such as the days when precipitation is at least 10 mm, 20 mm, 30 mm, at least 65 mm but less than 100 mm, at least 100 mm but less than 115 mm, at least 115 mm but less than 205 mm, and at least 205 mm, and intensity definitions, such as SDII, RX1day, RX3day, RX5day, PRCPTOT, R95pTOT, and R99pTOT. Temporal trends in extreme events identified by 16 different methods were assessed using both the modified Mann-Kendall (MK) method and Sen's Slope Estimator (SSE).Analysis of the ERA5 reanalysis product indicated a 0.33-day-per-year increase in consecutive dry days (CDD) during 1961-2014 over Bangladesh, revealing that Bangladesh may be drying out at a faster rate than previously anticipated. For average daily wet-day precipitation intensity (SDII), ERA5 and MIROC6 showed a decrease at annual rates of -0.07 and -0.06 mm per day, respectively. If these trends continue over the next few years, Bangladesh may encounter water scarcity. In addition, a decrease at a rate of -0.09 days per year in R65mm was found in ERA5, while other frequency definitions do not have statistically significant trends. MIROC-ES2L has the closest agreement to ERA5 in terms of Percentage BIAS (PBIAS), R-Squared (R2), Root Mean Squared Error (RMSE), and Mean Squared Error (MSE) metrics, followed by EC-Earth3-Veg-LR, IPSL-CM6A-LR, and MIROC6. Several recommendations for future studies and improvements are also included in this study. Results presented in this study, specifically a faster drying rate, fewer days with 65-100 mm of daily precipitation, and possibly less monsoon seasonal precipitation are important for the development of adaptation strategies in Bangladesh.
Stratospheric climate anomalies and ozone loss caused by the Hunga Tonga volcanic eruption
Authors: Randel William , Wang Xinyue , Zhu Yunqian , Tilmes Simone
Published: February 2023

The Hunga Tonga volcanic eruption in January 2022 injected extreme amounts of water vapor (H2O) and a moderate amount of aerosol precursor (SO2) into the Southern Hemisphere (SH) stratosphere. The H2O and aerosol perturbations have persisted and resulted in large-scale SH stratospheric cooling, equatorward shift of the Antarctic polar vortex, and slowing of the Brewer-Dobson circulation associated with a substantial ozone reduction in the SH winter midlatitudes. Chemistry-climate model simulations forced by realistic HTHH inputs of H2O and SO2 reproduce the observed stratospheric cooling, circulation changes and ozone loss, demonstrating the observed behavior is due to the volcanic influences. Furthermore, the combination of aerosol transport to polar latitudes and a cold polar vortex enhances springtime Antarctic ozone loss, consistent with observed polar ozone behavior in 2022.
Dragon-king detection for real-time forecast of catastrophic rock slope failures
Authors: Lei Qinghua , Sornette Didier , Yang Haonan , Loew Simon
Published: February 2023

Catastrophic rock slope failures pose great threats to life and property, but remain difficult to predict. Over the past decades, great efforts have been devoted to develop and deploy high-precision monitoring technologies to observe unstable rock slope movements. However, only a limited number of large rock slope failures have been so far successfully mitigated. Here, we present a novel predictive framework to quantitatively assess the slope failure potential in real time. Our method builds upon the physics of extreme events in natural systems: the extremes so-called “dragon-kings” (e.g. slope tertiary creeps prior to failure) exhibit statistically different properties than other less intense deformations (e.g. slope secondary creeps). We develop robust statistical tools to detect the emergence of dragon-kings during rockslide evolution, with the secondary-to-tertiary creep transition quantitatively captured. We also construct a phase diagram characterising the detectability of dragon-kings against “black-swans” and informing on whether the slope evolves towards a catastrophic or slow landslide. We test our method on both synthetic and real datasets, demonstrating how it might have been used to forecast three representative historical rockslide events at Preonzo (Switzerland), Veslemannen (Norway), and Moosfluh (Switzerland). Our method, superior to the conventional velocity threshold approach, can considerably reduce the number of false alarms and identify with high confidence the presence of true hazards of catastrophic rock slope failures. Our work adds a new conceptual framework and operational methodology with a significant potential to reduce landslide risks and support existing early warning systems.
EMIRS observations of temperature and dust aerosols: Seasonal and diurnal variability
Authors: Haider Syed A. , Majeed Tariq , Shah Siddhi
Published: February 2023

Recently, Emirates Mars Mission (EMM) arrived at Mars on 9 February 2021. It carried three instruments: (1) Emirates eXploration Imager (EXI), (2) Emirates Mars Infrared Spectrometer (EMIRS), and (3) Emirates Mars Ultraviolet Spectrometer (EMUS). In this paper we have used EMIRS data. The EMIRS instrument is measuring atmospheric temperature (at 0.5 mbar) and the column abundance of dust aerosols (referenced to 9 μm), water ice clouds (referenced to 12 μm), and water vapour (pr-μm). These observations were taken between 24 May, 2021 (MY 36, Ls= ~ 50o) and 24 February, 2022 (MY36, Ls = 180o). There is a gap in these data between Ls = 100o and 120o due to the solar conjunction and the spacecraft entering into safe mode. We have studied the seasonal and diurnal variability of surface temperature and dust aerosols in the Martian atmosphere. These observations are reported at Ls= 5o interval and 2o interval in latitude. The data are averaged over longitude. Our results show that Mars was relatively cool with little dust. The growth and decay of regional dust storms were observed by EMIRS instrument. Based on our analysis we conclude that EMIRS instrument is well suited for the study of temporal and seasonal variability of atmospheric temperature and column integrated quantities of dust. Detailed analysis of these observations will improve our understanding of the underlying physical processes. It will also help to validate and tune GCM models. The EMIRS observations are always providing an exciting new information as we enter the dust perihelion season.  
The Malolotsha Klippe: Large-Scale Subhorizontal Tectonics Along the Southern Margin of the Archean Barberton Greenstone Belt, Eswatini
Authors: Heubeck Christoph , Thomsen Tonny Bernt , Heredia Benjamin D. , Zeh Armin , Balling Philipp
Published: February 2023

Whether Archean tectonics were horizontally or vertically dominated is controversially discussed because arguments bear on the kinematics and thermal state of the Archean mantle and constrain the mode of formation of the earliest continental crust. Highly deformed strata of Archean greenstone belts figure prominently in this debate because they record long periods of time and multiple deformation phases. Among the best-preserved greenstone belts counts the Barberton Greenstone Belt (BGB) of southern Africa. Geological mapping of part of the southern BGB in Eswatini (Swaziland), combined with U-Pb zircon dating, shows that the region preserves a tightly re-folded imbricate thrust stack in which metavolcanic and -volcaniclastic strata of the Onverwacht Group, deposited at 3.34–3.29 Ga, have been thrust on top of ca. 3.22 Ga siliciclastic strata of the Moodies Group. The structurally highest element, the Malolotsha Syncline, forms a tectonic klippe of substantial size and is >1,450 m thick. Forward modeling of a balanced cross section indicates that this thrust stack was part of a northwestward-verging orogen along the southern margin of the BGB and records a minimum horizontal displacement of 33 km perpendicular to its present-day faulted, ductily strained and multiply metamorphosed margin. Because conglomerate clasts indicate a significantly higher degree of prolate strain which extends further into the BGB than at its northern margin, late-stage tectonic architecture of the BGB may be highly asymmetrical. Our study documents that the BGB, and perhaps other Archean greenstone belts, preserves a complex array of both vertically- and horizontally-dominated deformation styles that have interfered with each other at small regional and short temporal scales.
Equatorial Electrojet and Counter Electrojet caused by the 15 January 2022 Tonga Volcanic Eruption
Authors: Le Guan , Liu Guiping , Yizengaw Endawoke , Englert Christoph
Published: February 2023

We present space and ground-based multi-instrument observations demonstrating the impact of the 2022 Tonga volcanic eruption on dayside equatorial electrodynamics. A strong counter electrojet (CEJ) was observed by Swarm and ground-based magnetometers on 15 January after the Tonga eruption and during the recovery phase of a moderate geomagnetic storm. Swarm also observed an enhanced equatorial electrojet (EEJ) preceding the CEJ in the previous orbit. The observed EEJ and CEJ exhibited complex spatiotemporal variations. We combine them with the Ionospheric Connection Explorer (ICON) neutral wind measurements to disentangle the potential mechanisms. Our analysis indicates that the geomagnetic storm had minimal impact; instead, a large-scale atmospheric disturbance propagating eastward from the Tonga eruption site was the most likely driver for the observed intensiYcation and directional reversal of the equatorial electrojet. The CEJ was associated with strong eastward zonal winds in the E-region ionosphere, as a direct response to the lower atmosphere forcing.
Ordering of small parameters in nonlinear wave problems
Authors: Burde Georgy
Published: February 2023

It is a common situation when asymptotic methods are applied to nonlinear wave problems which involve several parameters assumed to be small. As a canonical example, the classical problem of shallow water waves in ideal fluid may be mentioned. In particular, the famous Korteweg–de Vries (KdV) equation, which is the prototypical example of an exactly solvable soliton equation, was first introduced in the context of that problem. The system of equations describing the long, small-amplitude wave motion in shallow water with a free surface involves two independent small parameters: the amplitude parameter α and the wave length parameter β. No relationship between orders of magnitude of α and β follows from the statement of the problem. In the derivation of model equations, the question of ordering is usually not discussed and it is tacitly assumed that the two small parameters are of the same order of magnitude (the derivation of the KdV equation is the case). However, it is evident that there are no grounds for that assumption and that, in general, the parameters α and β can be not of the same order of magnitude. It is indicated in [1], that, in such a case, a consistent truncation of the asymptotic expansion can be made only on the basis of a prescribed relationship between orders of magnitude of α and β, and a systematic procedure for deriving an equation for surface elevation is developed. The results of the analysis provide a set of consistent model equations for unidirectional water waves which replace the KdV equation in the cases of the nonstandard ordering. The problem of shallow water waves over a slowly varying bottom [2], [3] provides an example of the problem which involves three independent small parameters. As other examples of the problems involving several small parameters, the nonlinear interactions among internal oceanic gravity waves and nonlinear instability of (weakly) nonparallel flows are to be considered.

[1] G. I. Burde and A. Sergyeyev, J. Phys. A: Math. Theor. 46, 075501 (2013).[2] A. Karczewska, P. Rozmej, and E. Infeld, Phys. Rev. E 90, 012907 (2014).[3] G. I. Burde, Phys. Rev. E 101, 036201 (2020).
Unveiling the Mechanisms and Implications of Vegetation Carbon Dynamics for the last two decades in India
Authors: Kashyap Rahul , Kuttippurath Jayanarayanan
Published: February 2023

Abstract In recent decades, vegetation cover and productivity exhibit substantial variability around the globe. Both climate drivers and human induced changes significantly impact vegetation, which is not adequately explored for the Indian region. Here, we use satellite and reanalysis data to unravel the phenomena driving the greening/browning of India. The analysis shows that India is largely greening (62.5%) and marginally browning (14.1%). This greening is predominantly by the contribution of croplands (72.3%), led by Zaid (70.1%), followed by Kharif (59.5%) and Rabi (54.8%) agricultural seasons of India. Among the climate drivers, soil moisture (44%) has the major influence followed by temperature (32%) and precipitation (23%). Greening is predominantly observed in the north west due to positive influence of both increased soil moisture and decreased temperature, termed as the ‘moisture induced greening’. The Indo-Gangetic plain (IGP) is the most extensively irrigated region in the world, which results in greening. Drying due to warming and increased soil heat flux, termed as the ‘warming induced moisture stress’, suppresses Gross Primary Productivity (GPP) (i.e., browning), mainly in the croplands of southern India and eastern IGP. Granger causality test reveals that warming induced moisture stress is taking place at a lag of 1 month in these areas. We also examined the Carbon Use Efficiency (CUE), a metric to define the ability of plants to sequester carbon from atmosphere, of vegetation in different regions. Water availability as soil moisture (32%) and precipitation (26%) has strong positive influence on CUE, establishing its importance in driving vegetation carbon dynamics (VCD) for cropland dominated India. Our analysis shows enhanced productivity (greening) in regions of lower (< 0.3) CUE in western India (moisture induced greening) and IGP (irrigation induced agricultural boom). However, a reduced productivity (browning) is found in the northeast, east (deforestation and extreme events) and south (warming induced moisture stress) India in regions of higher (> 0.6) CUE, which is a concern. Effective management of croplands and conservation of forest resources is the key to achieve sustainable development goals (SDGs). Furthermore, it serves as a tool to counter the challenges of food security, global warming and climate change.Keywords: Greening; Browning; Vegetation carbon dynamics (VCD); Soil Moisture; Food security; Climate Change
Wave boundary layer at the ice–water interface: theory and experiment
Authors: Yu Jie , Orzech Mark , Wang David , Landry Blake , Zuniga-Zamalloa Carlo , Trubac Kathryn
Published: February 2023

Marginal ice zones (MIZs) are distinguished by the highly heterogeneous condition of sea ice, e.g., floes of various sizes, pancake, brash and frazil ice, ice ages, brine content, ice thickness and concentration, etc. This makes it challenging to model wave propagation in MIZs, either theoretically or numerically, since there remain similar limitations to mathematically describing such an ice cover on the ocean surface. In this study, we re-consider the problem of linear gravity waves in two layers of fluids with a viscous ice layer overlaying water of deep depth, giving a comprehensive analysis of the fluid velocities, velocity shear, and Reynolds stress associated with wave fluctuations in both the ice layer and the wave boundary layer just beneath the ice. For the turbulent wave boundary layer, water eddy viscosity is used. Speculation of the Eulerian steady streaming is made based on the Reynolds stress distribution, offering a preliminary insight into the wave-induced mean drifts in both the ice layer and wave boundary layer in the water. For wave attenuation, the results using a typical ice viscosity and a reasonable water eddy viscosity show good agreement with data over the range of frequencies for both field and lab waves, significantly outperforming those results assuming an inviscid water. Also discussed are the PIV (particle imaging velocimetry) measurements from the experiment of wave propagation through broken surface ice in a salt water tank in a temperature-controlled facility at the US Army Corps of Engineers Cold Regions Research and Engineering Laboratory (CRREL). Preliminary analysis of the PIV data has provided strong evidence of such a wave boundary layer at the water–ice interface. The measured vertical profiles of fluid velocities and wave-induced Reynolds stress have trends similar to the theoretical predictions, despite the quantitative discrepancies in terms of numerical values. To our knowledge, this is only the second such experiment to measure the three-dimensional fluid velocity fields due to the wave motion under surface ice. This is to be followed by the phase II experiment (scheduled in 2023) in which the ice thickness and other properties will be configured to improve the similitude with field applications. 
Drivers of Laptev Sea interannual variability in salinity and temperature from satellite data
Authors: Hudson Phoebe , Martin Adrien , Josey Simon , Marzocchi Alice , Angeloudis Athanasios
Published: February 2023

Arctic surface air temperatures are warming twice as fast as global average temperatures. This has caused ocean warming, an intensification of the hydrological cycle, snow and ice melt, and increases in river runoff. Rivers play a central role in linking the components of the water cycle and Russian rivers alone contribute ~1/4 of the total freshwater to the Arctic Ocean, maintaining the halocline that covers the Arctic and dominates circulation. Increases in river runoff could further freshen this layer and increase Arctic Ocean stratification. However, the increase in atmosphere-ocean momentum transfer with sea ice loss could counteract or alter this pattern of circulation, mixing this cold fresh water with the warm salty water that currently sits below it. Understanding the interplay between these changes is crucial for predicting the future state of the Arctic system. Historically, studies trying to understand the interplay between these changes have been challenged by the difficulty of collecting in situ data in this region. Over most of the globe, L-band satellite acquisitions of sea surface salinity (SSS), such as from Aquarius (2011–2015), SMOS (2010- present), and SMAP (2015-present), provide an idea tool to study freshwater storage and transport. However, the low sensitivity of L-band signal in cold water and the presence of sea ice makes retrievals at high latitudes a challenge. Nevertheless, retreating Arctic sea ice cover and continuous progress in satellite product development make the satellite based SSS measurements of great value in the Arctic. This is particularly evident in the Laptev Sea, where gradients in SSS are strong and in situ measurements are sparse. Previous work has demonstrated a good consistency of satellite based SSS data against in situ measurements, enabling greater confidence in acquisitions and making satellite SSS data a truly viable potential in the Arctic. Therefore, this project aims to combine satellite data, particularly SMAP and SMOS sea surface salinity (SSS) data, with model output to improve our understanding of interactions between the components of the Arctic hydrological cycle and how this is changing with our changing climate. The Laptev Sea was chosen as an initial region of focus for analysis as the Lena river outflows as a large, shallow plume, which is clearly observable from satellite SSS data. The spatial pattern of the Lena river plume varies considerably interannually, responding to variability in atmospheric and oceanic forcing, sea ice extent, and in the magnitude of river runoff.  Numerical model output and satellite products confirm what has previously been suggested from in-situ data: wind forcing is the main driver of river plume variability.
Mercury evidence global volcanic effects during the Permian-Triassic transition
Authors: Shen Jun
Published: February 2023

The latest Permian mass extinction (LPME) was triggered bymagmatism of the Siberian Traps Large Igneous Province (STLIP), which left an extensive record of sedimentary Hg anomalies at Northern Hemisphere and tropical sites. Here, we present Hg records from terrestrial sites in southern Pangea, nearly antipodal to contemporaneous STLIP activity, providing insights into the global distribution of volcanogenic Hg during this event and its environmental processing. These profiles (two from Karoo Basin, South Africa; two from Sydney Basin, Australia) exhibit significant Hg enrichments within the uppermost Permian extinction interval as well as positive Δ199Hg excursions (to ~0.3‰), providing evidence of long-distance atmospheric transfer of volcanogenic Hg. These results demonstrate the far-reaching effects of the Siberian Traps as well as refine stratigraphic placement of the LPME interval in the Karoo Basin at a temporal resolution of ~105 years based on global isochronism of volcanogenic Hg anomalies.
Black carbon-climate interactions regulate dust burdens over India revealed during COVID-19
Authors: Wei Linyi , Wang Yong , Lu Zheng , Liu Xiaohong
Published: February 2023

India as a hotspot for air pollution has heavy black carbon (BC) and dust (DU) loadings. BC has been identified to significantly impact the Indian climate. However, whether BC-climate interactions regulate Indian DU during the premonsoon season is unclear. Here, using long-term Reanalysis data, we show that Indian DU is positively correlated to northern Indian BC while negatively correlated to southern Indian BC. We further identify the mechanism of BC-dust-climate interactions revealed during COVID-19. BC reduction in northern India due to lockdown decreases solar heating in the atmosphere and increases surface albedo of the Tibetan Plateau (TP), inducing a descending atmospheric motion. Colder air from the TP together with warmer southern Indian air heated by biomass burning BC results in easterly wind anomalies, which reduces dust transport from the Middle East and Sahara and local dust emissions. The premonsoon aerosol-climate interactions delay the outbreak of the subsequent Indian summer monsoon.
pyRCIT - A rainfall nowcasting tool based on a synthetic approach
Authors: He Ting , Einfalt Thomas
Published: February 2023

Operating precise rainfall nowcasting with the help of observations from weather radar can give an effective warning before hydrometerological hazards occur. A common radar based rainfall nowcasting procedure includes: rain cell identification and tracking, spatial and temporal analysis of rain cell, rainfall nowcasting and nowcasting results evaluation.In this study, an open source rainfall nowcasting tool - pyRCIT is designed and developed which is purely based on qualified weather radar data. It have four main modules: (1) weather radar data processing; (2) rainfall spatial and temporal analysis; (3) deterministic rainfall nowcasting and (4) ensemble rainfall nowcasting. In pyRCIT, rainfall is firstly obtained from weather radar data sets with a series of data quality adjustment procedures. Secondly, rain cells are identified and their spatial and temporal properties are analyzed by the RCIT algorithm. Thirdly, deterministic rainfall nowcasting is operated following the extrapolating schema using lagrangian persistence and semi-lagrangian methods separately, nowcasting results are evaluated by the object oriented verification method - SAL (Structure-Amplitude-Location). Finally, nowcasting uncertainties are analyzed by the random field theory and the quantified uncertainties are implemented as the aid of ensemble rainfall nowcasting.Nowcasting quality of pyRCIT are evaluated by comparing it with some main rainfall nowcasting methods: TREC, SCOUT and pySTEPS. Comparative results showed that deterministic nowcasting score of pyRCIT were higher than the TREC and SCOUT methods but is nearly equal to the score of pySTEPS, for the ensemble nowcasting, score of pyRCIT is higher than all three methods for the selected cases. The pyRCIT can serve as the basis for further hydro-meteorological applications such as spatial and temporal analysis of rainfall events and flash flood forecasting.The code of pyRCIT is available at https://github.com/greensubriane/PYRCIT.git
Impact of soil organic carbon - gravel parameterization scheme on soil water and heat transport on the Tibetan Plateau
Authors: Yuan Yuan
Published: February 2023

In this paper, the CLM5.0 organic carbon – gravel (OC – G) parameterization scheme was used to simulate soil temperature and moisture on the Tibetan Plateau from 1990 to 2018. Correlation between the simulated and observed soil temperature or moisture was higher, and the error was smaller, after the modification of the parameterization scheme. This improvement justifies the applicability of the scheme for soil hydrothermal simulations on the plateau. The effects of soil organic carbon (SOC) and gravel content on soil temperature and moisture across the plateau were also evaluated, and show that increasing SOC content increased soil moisture and decreased soil temperature, with the southeastern key area being most sensitive to SOC and gravel content. With increasing gravel content, soil moisture decreased and soil temperature increased, especially in the northwestern key areas. However, in general, soil on the plateau was more sensitive to changes in SOC content, and when the SOC and gravel content changed at the same time, the effects on soil temperature and moisture were a “cumulative” effect. The change directly affected the memory time of soil temperature and moisture in summer over the plateau. Specifically, when the organic carbon content was increased, the memory time of surface soil moisture increased in the northwest and decreased in the southeast. When gravel content was increased, the memory time of surface soil moisture decreased in the northwest but increased in the southeast, and the memory time of soil temperature remained largely unchanged. Changes to the abnormal duration may alter summer weather and climate in Eastern China.
Groundwater Flow Mechanisms and Related Carbon Sink Potential in Coastal Blue Carbon Ecosystems
Authors: Chen Xiaogang , Li Ling
Published: February 2023

Mangroves and saltmarshes are important coastal blue carbon ecosystems characterized by high soil carbon storage. Groundwater flow and associated carbon export in mangroves and saltmarshes is the frontier and challenging issue in the estimates of coastal blue carbon sinks. Large amounts of groundwater-derived sediment carbon outwelling remains in the ocean and may represent an important carbon sink, which are potentially significant yet poorly understood components of mangrove and saltmarsh carbon budgets. This study aims to how to quantify the groundwater flow and related carbon fluxes, analyze their driving mechanisms, and then reassess the carbon budget and carbon sink potential of mangroves and saltmarshes.
Comparing dual porosity approach and discrete fracture network for modelling seawater intrusion in fractured porous media
Authors: Baalousha Husam , Koohbor Behshad , Fahs Marwan , Younes Anis
Published: February 2023

Coastal aquifers are very important as they provide water supply for more than one billion inhabitants around the world. Due to the increased stresses on the coastal aquifers and the anticipated sea level rise from climate change, the risk of seawater intrusion is high. Most of coastal aquifers around the Mediterranean and in the Middle East are comprised of fractured limestone. While numerous studies have been done to investigate flow in coastal aquifers, these studies consider classical flow in un-fractured aquifers. The seawater intrusion in fractured aquifers remains unexplored.This study focuses on simulating seawater intrusion in fractured porous media using the dual porosity approach (DP). A new numerical model is developed for sweater intrusion with the DP approach, based on advanced finite element schemes. The newly developed model is applied to the common benchmark of Henry’s problem and verified by comparison against a semi-analytical solution and a standard finite element solution obtained with COMSOL Multiphysics. The newly developed model is used to perform a sensitivity analysis for understanding the effect of parameters on the model predictions. The results show that the salinity in the domain is mainly controlled by the mass exchange rate between fractures and porous matrix. The DP approach is compared to the discrete fracture (DF) approach, via an inverse approach procedure. Synthetic observation data are generated with the DF approach and then used to calibrate the DP model. Agreement between the predictions of the DP and DF approaches depends on the fracture density.
Mean, variance, and trends of Levant precipitation over the past 4500 years from reconstructed Dead Sea levels and stochastic modeling
Authors: Morin Efrat , Ryb Tamar , Gavriely Ittai , Enzel Yehouda
Published: February 2023

A novel quantitative assessment of late Holocene precipitation in the Levant is presented, including mean and variance of annual precipitation and their trends. A stochastic framework was utilized and allowed, possibly for the first time, linking high-quality, reconstructed rises/declines in Dead Sea levels with precipitation trends in its watershed. We determined the change in mean annual precipitation for 12 specific intervals over the past 4500 yr, concluding that: (1) the twentieth century was substantially wetter than most of the late Holocene; (2) a representative reference value of mean annual precipitation is 75% of the present-day parameter; (3) during the late Holocene, mean annual precipitation ranged between −17 and +66% of the reference value (−37 to +25% of present-day conditions); (4) the driest intervals were 1500–1200 BC and AD 755–890, and the wettest intervals were 2500–2460 BC, 130–40 BC, AD 350–490, and AD 1770–1940; (5) lake-level rises and declines probably occurred in response to trends in precipitation means and are less likely to occur when precipitation mean is constant; (6) average trends in mean annual precipitation during intervals of ≥200 yr did not exceed 15mm per decade. The precipitation trends probably reflect shifts in eastern Mediterranean cyclone tracks.
Case study on the detection and quantification of the gas flares on the southeastern continental shelf of the East Sea, Korea
Authors: Kim Young-Jun , Chun Jong-Hwa , Kong Gee-Soo , Alarcon Mario E. Veloso , Cukur Deniz , Yoon Youngho , Kim Jung-Ki , Choi Joung-Gyu
Published: February 2023

Since most of the shallow gas is composed of methane, studies on its availability as a resource and global warming are being conducted. A gas flare is called a phenomenon in which shallow gas escapes from the sub-bottom into the seawater. Gas flares cause seafloor deformation and can trigger large-scale geohazards such as landslides and tsunamis. We discovered the gas flares in 2021 and 2022 by conducting seismic and acoustic surveys using R/V TamaheⅡ seismic vessel at the southeastern continental shelf of the East Sea in Korea. The gas flares were detected on the water column data obtained by an EK60 of 38 kHz frequency and a multi-beam echo sounder of 20 – 40 kHz frequency bands (Kongsberg EM2040). We observed the deformation of the seafloor and sub-bottom using a Chirp sub-bottom profiler (SBP) of 2 – 7 kHz frequency bands (FalMouth HMS-622 CHIRPceiver). The water depth of the survey area ranges from 130 to 140 m. Four gas flares are distributed within approximately 3.5 km in a northwest-southeast direction. The height of the gas flare is about a maximum of 100 m from the seafloor. The seafloor where the gas escaped was observed to deform into dome shapes and pockmark. Additionally, we performed the seismic survey using a 60 in3 mini GI gun and a 48-channel streamer cable with a 12.5 m group interval to detect the source layer of shallow gas and the migration pathways. We tried using VBALab software to quantify the gas flow rate on the acoustic data of EK60.