bluuebunny/crossref_metadata_2025 huggingface dataset:
Combining Remote Sensing and On-site Observations to Explore Salinization Dynamics in the Po River Delta 
Authors: Ghiardelli Aurora , Straffelini Eugenio , Cucchiaro Sara , Tarolli Paolo
Published: March 2024

Seawater intrusion (SWI) is an escalating concern in coastal regions globally, with alterations in weather patterns and sea-level rise emerging as pivotal factors contributing to the occurrence of SWI in both surface waters and groundwater. This phenomenon poses a significant risk to low-lying agricultural areas, leading to soil salinization with substantial adverse effects on soil quality and crop yields. In the Po River Delta, Italy's broadest agricultural region impacted by SWI, summer droughts play a pivotal role in driving SWI dynamics. Within this extensive lowland area, the deficiency in rainfall during the summer months reduces river flow, facilitating the inland movement of seawater. The escalating frequency of drought events and exceptionally high temperatures in recent summers, has highlighted the necessity for a thorough understanding of the impact of SWI on cropland, both on vegetation and soil, to detect any possible correlations between SWI, accumulation of salts and plant stress. The objective of this study is to combine multi-temporal remote sensing from satellite imagery, to monitor plant greening, with on-site observations of soil electrical conductivity (EC). Normalized Difference Vegetation Index (NDVI) maps for the summer period 2023 were elaborated from satellite data, classifying cropland with a machine-learning algorithm to filter bare soil and surface water from green vegetation. In the same time period, two experimental sites located in the delta region were periodically sampled with a Time Domain Reflectometry (TDR) probe to monitor soil temperature, moisture and EC. Soil samples were also collected and analyzed to measure EC of the water extracts. Although summer 2023 was not characterized by extreme drought, the combined results offered a quick method for identifying salinization trends within the delta cropland area, pinpointing the most susceptible areas both on a regional scale and on a local scale.
Geomorphological evolution of the Eastern Sardinian Margin (Western Tyrrhenian) from the Messinian to the Plio-Quaternary: New evidence for post-rift deformation from bathymetric and seismic data.
Authors: Sylvain Romain , Gaullier Virginie , Chanier Frank , Watremez Louise , Caroir Fabien , Graveleau Fabien , Lofi Johanna , Maillard Agnès , Sage Françoise , Thinon Isabelle , Travan Gaia
Published: March 2024

The hyper-extended Eastern Sardinian margin is due to the eastward migration of the Appennine-Calabria subduction zone, creating the Neogene back-arc Tyrrhenian Basin. This area was affected by strong erosion during the Messinian Salinity Crisis (MSC, 5.97 - 5.33 Ma) on the continental shelf and slope leading to a major discontinuity, known as the Messinian Erosion Surface (MES), constituting, therefore, a remarkable stratigraphic marker. It is also a powerful paleo-topographic marker of the MSC times and can be used as a marker of the deformation during Plio-Quaternary times. The end of the rifting phase in the Eastern Sardinian margin is dated during the Tortonian (11.63 - 7.25 Ma) attested by the occurrence of a relatively thick syn- and post-rift sequence pre-dating the MES.The “METYSS 4” cruise led to the acquisition of more than 2,000 km of very high-resolution (VHR) seismic reflection data, following a dense grid, on the Eastern Sardinian continental shelf and slope, which has been little explored until now. Seismic interpretation allowed for mapping the major erosion surface, the MES, across the continental shelf and slope. At the base of the PQ sequence, the MSC paleo-topography highlights a hydrographic paleo-network identical to the current one and a general progradation of the shelf-break toward the east during the Plio-Quaternary. In the southern part of the study area, several east-dipping normal faults, oriented N-S, significantly shift the MES (between 5 and 55 m; assuming sound wave velocity of 1700 m/s in Plio-Quaternary sediments). The MES is tilted toward the fault and is covered by Plio-Quaternary deposits, which display a fan-shaped geometry (eg. 50 m thick on the hanging wall). These NS-trend faults are cross-cut by E-W trending messinian canyon and this fault pattern is also observed on the other flank of the canyon. The along-strike geomorphological analysis of canyons reveals the occurrence of knickpoints (slope breaks) coinciding with the front of the two fault patterns. Moreover, the shifts in water depth of most knickpoints are at the same order of amplitude than fault offsets (ie. 10 to 50 m). These geomorphologic markers reinforce the hypothesis that the fault activity is recent (ie. less than 5 Ma). We interpret these observations as markers of a recent reactivation of the structures inherited from the rift in the western part of the Tyrrhenian Sea.
Precipitation bias correction: A novel method combining wavelet analysis and quantile mapping (WA-QM)
Authors: Wu Xia , Liu Zhu , Duan Qingyun
Published: March 2024

While CMIP6 has made notable improvements compared to CMIP5, there are still biases present in its simulations of different climate features due to limitations in model physics and uncertainties in input data. To address these biases, effective bias correction methods need to be employed. One commonly used method is quantile mapping, which aligns the probability density function (PDF) of climate simulations with observed data. However, this method has a limitation as it fails to maintain the temporal correspondence between model predictions and observations.To overcome this limitation, a new approach called Wavelet Analysis-Quantile Mapping (WA-QM) has been proposed. This method involves decomposing GCM simulations into different frequency bands using discrete wavelet transformation. The scaling factors of these bands are adjusted based on their correlations with observed data. Additionally, a quantile mapping procedure is applied to modify the overall PDF of the simulations.The WA-QM method was tested in monthly precipitation simulation data from five CMIP6 models covering the period 1951-2010 in the Pan Third Pole (PTP) region, which includes the Tibetan Plateau, Central Asia, and Southeast Asia. Results showed that WA-QM combines the advantages of wavelet analysis and quantile mapping. It effectively improves the representation of seasonal and monthly climatology varying through wavelet analysis, while also correcting mean and variance biases using quantile mapping. Consequently, the PDF closely resembles the observed data. The effectiveness of the WA-QM approach extends to correcting precipitation biases across different spatial areas and CMIP6 models.
Fast seafloor topography mapping of large oceanic provinces by optimization/parallelization
Authors: Seoane Lucia , Fuseau David , Ramillien Guillaume , Darrozes José , Plazolles Bastien , Rouxel Didier , Salaün Corinne , Schmitt Thierry
Published: March 2024

During the last decades, several inversion approaches have been proposed to derive sea floor topography from satellite-based gravity data. Unfortunately, the most accurate non linear ones are based on iterative schemes that remain very time-consuming, especially if the number of topographic heights to be fitted is very important, e.g. when the oceanic domain is large and/or the gravity data is geographically dense and thus the maximum grid resolution to be accessible is high. Our strategy of computation is to decompose the total area into geographical cells that are overlapped to cancel the edge effects. The reference ocean depth given by GEBCO and the elastic thickness for regional compensation in function of the square root of the age of the oceanic crust are assumed to be constant in each cell. The initial inversion code has been translated into C++ and optimized using Armadillo software and LAPACK library to obtain a gain of speed of 1000 for a large region such as the complete North Atlantic Ocean (-54,-26,18,37). Post-fit and absolute errors are typically less than 200 m and 50 m r.m.s. respectively. These new detailed maps of bathymetry represent a precious source of information for geophysical applications. 
Water and Carbon Dioxide Interactions in the most unlikely places: The hidden dynamics of the Sahara Desert soils
Authors: Bekin Nadav , Ashilenje Dennis , Chehbouni Abdelghani , Bouchaou Lhoussaine , Kouisni Lamfeddal , Kool Dilia , Agam Nurit
Published: March 2024

Soil CO2 efflux is primarily attributed to the metabolic activity of soil organisms and is a major component of the global carbon balance. The carbon balance of deserts, such as the Sahara Desert, the largest desert on Earth, is considered neutral as low soil moisture inhibits biological activity and reduces the soil CO2 efflux to its lower limit. Studies in the last decades challenge this paradigm, reporting a mysterious nocturnal CO2 uptake by desert soils, which in some cases leads to a net gain of carbon by the soil. While the factors controlling this phenomenon are still under debate, it is clear that the presence of water is essential. How, then, can nocturnal CO2 uptake occur in the driest soil conditions when no apparent water is available to drive the process? We embarked on a field expedition in the Sahara Desert, southwest Morocco, during the summer of 2022 to explore the dynamics of water and carbon in this presumably “stagnant” ecosystem. We discovered nocturnal water vapor adsorption, driven by atmospheric water vapor transported from the Atlantic Ocean and penetrating hundreds of kilometers inland where the vapor is captured in the soil’s top layer. Changes in soil water content were determined from soil relative humidity (measured using a profile of relative humidity sensors) and soil-specific vapor sorption isotherms (measured using a vapor sorption analyzer). With this novel method, we were able to detect a daily increase of 0.3 mm of water even at a distance of 250 km from the Ocean. Concurrent measurements of CO2 fluxes (measured using manual and automatic flux chamber systems), confirmed that small atmosphere-to-soil CO2 fluxes occurred during the night, coinciding with downward water vapor fluxes. This indicates that the atmosphere provides a consistent water source and may initiate soil CO2 uptake. Simultaneous measurements of water vapor and CO2 fluxes at a second site suggested that the quality of the correlation between the two fluxes depends on soil properties. Overall, the daily CO2 cycle was unbalanced (net uptake of 0.08 g m-2) implying that the soil acted as a carbon sink. This sink is small, but considering its occurrence even in inland desert ecosystems and the fact that arid and hyper-arid regions occupy 26% of Earth’s terrestrial surface, the effect of atmospheric water capture by desert soils on CO2 exchange may play a significantly larger role in the global carbon balance than previously thought. 
Quantifying seasonal bedload transport rates in a sub-arctic river using image velocimetry methods
Authors: Välimäki Juha-Matti , Lotsari Eliisa , Eltner Anette , Takala Tuure
Published: March 2024

The bedload transport rate is the quantified amount of sediment being transported in the active layer of the riverbed. Traditional measuring methods involving laborious mechanical equipment are unable to capture the spatial and temporal fluctuations of bedload transport rate and measurements done with these methods have large uncertainties caused by the disturbance of the hydraulic conditions of the riverbed by the equipment itself. Computer vision-based particle image velocimetry methods have been previously successfully applied to quantify bedload transport rates from video data sets in laboratory conditions, but not in ice-covered and open channel field conditions.The aims of this study are to 1) to apply image velocimetry methods to underwater video data sets to quantify seasonal bedload transport rates in different types of flow conditions and 2) understand the seasonal variation in bedload transport amounts based on both mechanical and image velocimetry methods.The study is based on field data, measured at sub-arctic Pulmanki river, located in northern Finland (~70°N latitude) and draining towards the Arctic Sea. The data has been gathered over 2021-2023 during winter (ice-covered, low flow), spring (open channel, high flow), and autumn (open channel, low flow) seasons to cover different possible sediment transport conditions. The preliminary results are presented. They show that the method is promising in enhancing the understanding of sediment transport processes and the seasonal transported amounts in sub-arctic river conditions.
Active Commuters’ Exposure to PM2.5, Black Carbon, Noise, and Heat During the Northeast Monsoon in Selected Urban Cities in Malaysia
Authors: Uding Rangga Josfirin , Ezani Eliani , Norkhadijah Syed Ismail Sharifah , Mohd Yusof Mohd Johari , Bahari Shamsudin Shamsul
Published: March 2024

Today, more than 70% of the Malaysian population lives in urban areas, and this proportion continues to increase. Changes in land use and land cover, as well as additional anthropogenic factors, have altered the energy balance and led to spatio-temporal variations in urban climate. Active commuters who travel near roadways with high traffic density face a range of exposures, such as traffic-related air pollution (TRAP), traffic noise (TN), and urban heat (UHI). As urbanisation and population acceleration increase, understanding the environmental stressors faced by active commuters becomes crucial. Our aim is to measure the weekly spatial and temporal variation of TRAP, TN, and UH in selected cities in Malaysia and assess the health risks of exposures. The assessment was conducted along the selected routes in Kuala Lumpur (KUL) city centre and Cyberjaya (CYB) in Malaysia. The sampling campaign was conducted in October and November 2023. This comprehensive assessment measured TRAP (i.e., PM2.5, black carbon (BC)), TN, and UH simultaneously. The TSI SidePak (AM510), microAeth (MA200), TSI Edge 5 Personal Noise Dosimeter, and QUESTemp 36 models were used to measure PM2.5, BC, TN, and UH, respectively. The preliminary findings indicate a significant difference between peak hours (morning, noon, and evening) for all parameters (p < 0.001), except for BC concentrations (p = 0.37) during weekdays. All parameters were significant (p < 0.001) during weekends in KUL (Route 1). For CYB (Route 2), there was a significant difference in PM2.5, BC, TN, and UH levels (p < 0.001) between peak hours on both weekdays and weekends. PM2.5 (73.31 µg/m3), BC (6.19 µg/m3), and TN (80.10 dB(A)) were significantly higher on weekdays in Route 1 compared to Route 2, while the heat index was also higher (27.90 °C) in Route 1. Similar findings showed higher levels of PM2.5 (85.14 µg/m3), BC (5.95 µg/m3), and TN (77.89 dB (A)) on weekends in Route 1. Our study will help to address the knowledge gap on the impact of urban heat, air pollution, and noise pollution on climate adaptation among active commuters in urban cities. The findings of this study will contribute to the development of targeted interventions and strategies to enhance the resilience of these active commuters to the adverse effects of urban stressors. Our examination will also add to the wider discussion on sustainable urban mobility, highlighting the importance of specific actions to improve the environmental conditions for those who use active modes of transport. This will eventually encourage healthier and more sustainable travel options.
Convection-Permitting simulations over South America: a look at the uncertainty sources at the sub-daily time scale
Authors: Raffaele Francesca , Coppola Erika , Silva Leidinice , Bettolli Maria Laura , Blasquez Josefina , Fernandez Jesus , Milovac Josipa , Porfirio da Rocha Rosmeri , Solman Silvina
Published: March 2024

A set of high resolution simulations have been performed over the La Plata region in South America, and a multi-model ensemble of Convection-Permitting simulations has been produced for a 3-years period (2018-2021). We have used this new high resolution ensemble to investigate more in depth the daily and hourly timescales.The available satellite and gridded observational datasets show a clear uncertainty  when going to sub-daily timescale, therefore the validation of the model ensemble mean and extreme precipitation is performed by including also a station based observational dataset at both daily and hourly time scale, to assess  the model uncertainty within the context of the aforementioned observational uncertainty.Moreover, a cluster analysis of the diurnal cycle precipitation has been used as a starting point for a spatial characterization of the precipitation in a region of heterogeneous topography. The ensemble models' performance has been validated inside five different regions in order to spatially homogenize the precipitation regimes at hourly timescales.The results underlined a good agreement in the model ensemble especially in those areas where the homogenization of the stations is more pronounced.On the other hand, the spread among models grow when looking at areas characterized by complex orography, thus highlighting the importance of having available a set of simulations as big as possible so that complexity can be represented within the  model uncertainty. 
Long-wavelength gravity and topography of the Pacific Ocean: Relative contribution of mantle dynamics and plate flexure 
Authors: Yang An , Watts Anthony , Zhong Shijie
Published: March 2024

It is widely recognized that mantle dynamics and plate flexure both contribute to Earth’s topography and gravity fields at different wavelengths, yet the actual transition wavelength between them is not well quantified, ranging from ~100 km to ~1000 km. Here we use the observed relationship between topography and the free-air gravity anomaly fields (admittance) to infer the relative contribution of plate flexure and mantle dynamics based on mantle flow models which incorporate an essentially elastic plate. Global and regional Pacific Ocean data studies show that plate flexure and mantle convection potentially contribute to the topography and gravity for wavelengths larger than ~600 km. Plate flexure mainly contributes at wavelengths shorter than ~600 km and is consistent with the support of uncompensated topography for wavelengths shorter than ~200 km. To investigate the admittance associated with mantle dynamics at long wavelengths we have constructed mantle flow models based on a number of different seismic tomography models. The finite element software CitcomS was used to calculate mantle flow and related surface dynamic topography and associated free-air gravity anomaly. Admittance analysis in the Pacific Ocean from different mantle flow models show that the dynamic admittance is generally larger than the observed admittance, while the admittance from plate flexure is smaller than the observed admittance, suggesting that both mantle dynamics and plate flexure contribute to Earth’s topography and gravity at long-wavelengths. The difference between the dynamic admittance and the observed admittance is smallest for cases with temperature-dependent viscosity and weak asthenosphere, and the combined admittance in the presence of both flexure and mantle convection for these cases is generally consistent with the observed admittance. We use a new method to separate the effects of plate flexure and mantle convection to the topography and gravity fields at long wavelengths which has been developed from the plate flexure and dynamic admittances. We assume that the topography and gravity at long wavelength are the combination of plate flexure and mantle dynamics and further assume that the topography and gravity are linearly related through the admittance. The final separated dynamic topography in the Pacific Ocean is generally consistent with previously published residual topography studies at long-wavelengths.
Tsunami early warning using high-frequency ocean radar system in the Kii Channel, Japan
Authors: Wang Yuchen , Imai Kentaro
Published: March 2024

The high-frequency (HF) ocean radar system is a shore-based remote sensing system that monitors sea surface currents, waves, and wind over large areas. It can measure tsunami-induced surface current velocity and provide information for tsunami early warning. An HF ocean radar system, installed by the Ministry of Land, Infrastructure, Transport, and Tourism in Japan, measured the tsunami velocity in the Kii Channel during the 2011 Tohoku earthquake. The Kii Channel is a strait that separates the Japanese island of Shikoku from the Kii Peninsula on the main island of Honshu. It connects the Osaka Bay with the Pacific Ocean.We adopted the tsunami data assimilation approach to predict coastal tsunami waveforms. It is a method that reconstructs the tsunami wavefield using offshore data without the need for source information (Maeda et al., 2015). To process the HF radar data as the input, we initially converted the current velocity along the beam direction to into u, v directions (i.e., EW, NS directions). This process also involved the spatial interpolation of observational points from the beam of two HF radar land stations. In addition, recognizing the tradeoff between the sampling rate and velocity resolution, we applied a 10-min moving average to enhance data quality. The processed velocity data exhibited consistency with numerical simulations derived from the source model of Satake et al. (2013). The data assimilation started at 08:05 (UTC, hereafter) on March 11, 2011.We predicted coastal tsunami waveform at Kobe, located in the Osaka Bay, and compared it with real observation recorded by the tide gauge. The forecast at 08:10 underestimated the tsunami amplitude, achieving an accuracy of 50.1% with a mean squared prediction error (MSPE) of 0.0101. However, the forecast at 08:20 matched well with the real observation, boasting an accuracy of 82.9% and a reduced MSPE of 0.0098. At 08:30, it continued to perform similarly, maintaining consistency between the predicted and observed waveforms. The accuracy was 81.3% and the MSPE further decreased to 0.0093. Given that the tsunami arrived in Kobe at 09:10, our approach can make an accurate prediction at least 50 min before its arrival.To summarize, we demonstrated the effectiveness of the HF ocean radar system in tsunami early warning. The case study of the 2011 Tohoku tsunami yielded a remarkable accuracy of over 80% at Kobe station. In the future, we will investigate the relationship between the number and location of HF radar observational points and the forecast accuracy.
Serverless Computing Architecture for Enhanced Martian Aurora Detection in the Emirates Mars Mission
Authors: Pacios David , Vázquez-Poletti José Luis , Dhurri Dattaraj B. , Atri Dimitra , Moreno Vozmediano Rafael , Lillis Robert J. , Schetakis Nikolaos , Gómez-Sanz Jorge , Di Iorio Alessio , Vazquez Luis
Published: March 2024

This work introduces a novel serverless computing architecture designed to analyze Martian auroras for the Emirates Mars Mission (Hope probe). Utilizing OpenCV and machine learning algorithms, the architecture offers efficient and scalable image classification, object detection, and segmentation. It leverages cloud computing's scalability and elasticity, handling large volumes of image data and adapting to varying workloads. Our study highlights the system's capacity to process and analyze images of Martian auroras swiftly while maintaining cost-effectiveness. The application of this technology within the HOPE Mission not only addresses the complexities involved in detecting Martian auroras but also sets a precedent for future remote sensing applications. Our results demonstrate the potential of serverless computing in enhancing the analysis of extraterrestrial phenomena and contributing significantly to planetary science.This contribution has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No.101007638 (Project EYE - Economy bY spacE) .
Modeling multiple concurrent soil erosion processes
Authors: Borrelli Pasquale , Panagos Panos , Alewell Christine
Published: March 2024

Healthy soil is essential for agriculture and ecosystem functioning. Changes in soil quality have an impact on the delivery of critical ecosystem services such as food production, water supply, and regulation. Soil erosion is notoriously ephemeral because it is dependent on the nexus of vulnerable soil, weather, and antecedent moisture levels; particularly the occurrence of climate extremes, such as big strong rainfall episodes or droughts with wind. When the right mix of events occurs, positive feedbacks can lead to erosion striking with disastrous environmental and socio-economic consequences. A situation that makes it important to better identify locations where multiple concurrent soil erosion processes may occur.
In this presentation we discuss (i) the geography of soil loss by water, wind, tillage, and crop harvesting erosion; (ii) their possible co-occurrence at EU (Borrelli et al., 2023a) and globally scale (Borrelli et al., 2023b); and (iii) how to better integrate research on soil erosion to improve modeling performances and to support decision-makers in both ex-ante and ex-post policy evaluation.
 
Acknowledgement. This research is part of the project “Accelerating collection and use of soil health information using AI technology to support the Soil Deal for Europe and EU Soil Observatory” (AI4SoilHealth) that received funding from the European Union’s Horizon Europe research and innovation programme under grant agreement No. 101086179.
 
References
Borrelli, P., Panagos, P., Alewell, C., Ballabio, C., de Oliveira Fagundes, H., Haregeweyn, N., ... & Robinson, D. A. (2023a). Policy implications of multiple concurrent soil erosion processes in European farmland. Nature Sustainability, 6(1), 103-112.
Borrelli, P., Alewell, C., Yang, J. E., Bezak, N., Chen, Y., Fenta, A. A., ... & Panagos, P. (2023b). Towards a better understanding of pathways of multiple co-occurring erosion processes on global cropland. International Soil and Water Conservation Research, 11(4), 713-725.
Fractal complexity evaluation of meteorological droughts over three Indian subdivisions using visibility Graphs
Authors: Rajesh Susan Mariam , Bahuleyan Muraleekrishnan , Nair GR Arathy , Sankaran Adarsh
Published: March 2024

Evaluation of scaling properties and fractal formalisms is one of the potential approaches for modelling complex series. Understanding the complexity and fractal characterization of drought index time series is essential for better preparedness against drought disasters. This study presents a novel visibility graph-based evaluation of fractal characterization of droughts of three meteorological subdivisions of India. In this method, the horizontal visibility graph (HVG) and Upside-down visibility graph (UDVG) are used for evaluating the network properties for different standardized precipitation index (SPI) series of 3, 6 and 12 month time scales representing short, medium and long term droughts. The relative magnitude of fractal estimates is controlled by the drought characteristics of wet-dry transitions. The estimates of degree distribution clearly deciphered the self-similar properties of droughts of all the subdivisions. For an insightful depiction of drought dynamics, the fractal exponents and spectrum are evaluated by the concurrent application of Sand Box Method (SBM) and Chhabra and Jenson Method (CJM). The analysis was performed for overall series along with the pre- and post-1976-77 Global climate shift scenarios. The complexity is more evident in short term drought series and UDVG formulations implied higher fractal exponents for different moment orders irrespective of drought type and locations considered in this study. Useful insights on the relationship between complex network and fractality are evolved from the study, which may help in improved drought forecasting. The visibility graph based fractality estimation evaluation is efficient in capturing drought and it has vast potential in the drought predictions in a changing environment.Keywords:  Drought, Fractal, SPI, Visibility Graph
Changes in potential evaporation over the last four decades in Hornsund SW Spitsbergen
Authors: Hanselmann Nicole , Osuch Marzena , Alphonse Abhishek Bamby , Wawrzyniak Tomasz
Published: March 2024

Svalbard is one of the fastest warming regions of the earth, over the last 40 years SW Spitsbergen has experienced large changes in hydrological and meteorological conditions. Evaporation is an important component of the hydrological cycle but remains understudied in High Arctic Svalbard. Cold climate evaporation in Spitsbergen is often neglected and commonly used evaporation estimates date to the early 2000’s. In this study, potential evaporation (PET) estimates for the period 1982 to 2023 were calculated using ten different PET models and meteorological data from the Polish Polar Station Hornsund (SW Spitsbergen). The ten potential evaporation methods includes radiation-based (Abtew), temperature-based (Hamon), radiation-temperature based (Hargreaves Samani) and combined models (Penman Montheit) and more. Trends in annual and interannual potential evaporation have been analyzed and compared to changes in meteorological conditions. The study evaluates the influence of the choice of PET model and the derived changes in potential evaporation estimates. The results of the study show a large spread in the amount of annual PET estimates ranging from ~30mm/y (Kharrufa) through ~300mm/y (Penman-Monteith) up to ~450mm/y (Abtew). Trends analysis shows different outcomes depending on the length of the averaging period. Using a daily timescale, PET models tend to show more similar patterns of changes than using monthly timescales. That corresponds well with changes in the meteorological conditions.
Crustal and upper mantle structure beneath Afar
Authors: Legendre Cédric P. , Kumar Utpal
Published: March 2024

The interaction of the Arabian, Nubian, and Somalian plates in the Afar triple junction is characterized by diverging plate dynamics along the Red Sea, Gulf of Aden, and East African rifts. Previous investigations using shear-wave splitting measurements and geodetic analyses have found that the average anisotropy aligns with the observed surface motion. However, the vertical layering of anisotropy in this region is yet to be accurately determined. In this study, we use earthquake seismic data to map Rayleigh-wave azimuthal anisotropy in the crust and lithospheric mantle beneath the East African Rift System. Our findings indicate the presence of layered anisotropy around the East African Rift System. 
At shorter periods, which sample the crust, we identified rift-parallel anisotropy near the rift, but in the central portion of the rift, rift-normal anisotropy was observed. At longer periods, which sample the lithospheric mantle, the anisotropic pattern exhibited significant differences. These observations suggest that the crust and lithospheric mantle are mechanically distinct below the East African Rift System. Likewise, these results imply the presence of complex dynamics within the crust and lithosphere in the region of the Afar triple junction.
A study on the enhancement mechanism of the eastward moving convective clouds over the Tibetan plateau and their enhancement in the secondary terrain
Authors: wang xiaofang
Published: March 2024

Using the cloud top blackbody brightness temperature (TBB) data retrieved from the FY-2B satellite observations in June-August 2010-2020, which is 1 ° × 1 ° per hour, the criterion is that the area of the cold cloud (TBB ≤ -32 ° C) is greater than or equal to 5000 km2, there were 114 cases of enhanced eastward moving convective systems over the Tibetan plateau（ECSs-TP） and 56 cases of weakened ECSs-TP  in the areas of secondary topography. Six types of major circulation patterns are obtained from the enhanced case study, of which the southwest vortex in the middle troposphere is the most significant. The favorable conditions are: At 500 hPa, there is a large gradient area of the meridional distribution of the potential height difference, i. e. , there is an obvious meridional disturbance in the middle troposphere. At 700 hPa, the southwesterly wind increment in the south of the secondary topography and the northward wind disturbance increment in the east of the plateau form an obvious cyclonic anomalous circulation.The whole-layer water vapor flux is the large value center of anomalous convergence, and the vertical wind shear and the equivalent potential temperature from the surface to 700 hpa are the large value regions of positive anomaly. 
    The heavy precipitation in the middle reaches of the Yangtze River caused by ECSs-TP with the development of the vortex system is analyzed. The vertical distribution of the non-adiabatic heating of convective clouds during the enhancement of the second-order precipitation is studied. It was found that the wet snow particles increased significantly near the melting layer during the enhancement of local precipitation, indicating that the falling and melting of snow particles contributed to the increase of precipitation. In addition, when the content of large raindrops under the melting layer increased, the content of graupel particles near the melting layer also showed a significant increase trend, indicating that the falling and melting of graupel also contributed to the increase of precipitation. The main source of non-adiabatic heating consists of two parts, one is the latent heat released by the condensation of water vapor into liquid phase particles, the other is the latent heat released by the condensation of water vapor into ice phase particles. The maximum value of the former appeared near 600hPa height, the maximum value of the latter appeared near 400hPa height, and the maximum value of the sum of the two appeared near 550hPa. For the latent heat released by the ice phase particles, the proportion of latent heat released by the ice phase particles is the largest.
Neoproterozoic-Early Paleozoic evolution of the southern Central Asian Orogenic Belt: constraints from eclogites in the Beishan Orogenic Belt (NW China)
Authors: Wang Tingyi , Cawood Peter A. , Diwu Chunrong , Zhao Guochun
Published: March 2024

Eclogites have provided important constraints on the processes of plate subduction, collision and the overall tectonic evolution of orogens. The Gubaoquan eclogite is the only one identified in the Beishan Orogenic Belt, which constitutes the southernmost part of the Central Asian Orogenic Belt. The protolith age and tectonic setting of the eclogite and associated rock units remain ill-constrained. U–Pb dating of the eclogite indicates a Neoproterozoic age of 887 ± 7 Ma for its protolith age and an Ordovician age of 461 ± 15 Ma for the eclogite facies metamorphism. Detailed U-Pb ages of zircons, monazites, rutiles and apatites from the eclogite and country rocks suggest that they have experienced multiple metamorphic events in the Neoproterozoic and Paleozoic, which are inferred to correlate with retrograde metamorphism during the later exhumation. The protoliths of the Gubaoquan eclogite are of continental origin, and along with the extensive distribution of the Neoproterozoic arc-related rocks probably resulted from assembly of Rodinia. This work was financially supported by the National Natural Science Foundation of China (41730213 and 41890831), Hong Kong RGC GRF grants (17307918), HKU Internal Grants for Member of Chinese Academy of Sciences (102009906) and for Distinguished Research Achievement Award (102010100), Northwest University Excellent Doctoral Thesis Cultivation Program (YB2023003), and from the Australian Research Council (FL160100168).
Tropical cyclone induced coastal flooding under current and future climates: A novel model framework for continental scale applications. 
Authors: Quinn Niall , Collings Thomas , Pranantyo Ignatius , Bruneau Nicolas , Wilkinson Hamish , Haigh Ivan , Haylock Malcolm
Published: March 2024

Coastal flooding, often triggered by the convergence of high tides and intense storm surges and waves, poses a grave threat to global coastal communities, leading to widespread property damage and loss of life. Tropical cyclones (TCs) in particular have been responsible for the majority of the most devastating coastal flood events in the recent years, causing billions of dollars in damages over the last decade within the US alone. Further, the compounded impact of rising sea levels, fuelled by a warming climate, along with projected population growth and continued development in the flood zone, is widely expected to increase these risks to coastal communities in the future. It is essential to many end users, from environmental mangers to (re)insurers, to accurately characterize the risk of coastal flooding over large, often national scales, both under current and highly uncertain, future climate conditions. This poses a number of challenges. For instance, in many of the most heavily impacted regions of the world, the majority of the coastal flooding stems from severe TC induced storm surge events. The rarity of these events means that the historical record alone is insufficient to truly capture the current risk, let alone represent the vast range of potential future climate conditions and their subsequent impacts upon TC-induced flood risk. To provide the information required catastrophe model frameworks that can efficiently represent the full range of potential flooding events, from hazard generation through to financial impacts, and how their frequencies might change through time, are essential. This research introduces a comprehensive TC-induced storm surge catastrophe modelling framework. An extensive catalogue of synthetic TC wind and pressure fields, under current and future climate forcing, is utilised. The SCHISM model suite is used to numerically model surge and waves to generate boundary conditions to the reduced physical solver, SFINCS, which is used to model the nearshore and overland inundation processes. Using an example US implementation, novel approaches developed to enable the efficient representation of approximately 2.5 million unique TC events are discussed, and preliminary results presented. The proposed catastrophe model framework offers a valuable tool for those interested in coastal flooding, enabling a robust evaluation of TC-induced risk under any climate scenario, over extensive geographical domains.   
Spatial and temporal distribution of all Arctic Polynyas since 1979
Authors: Wong Hau Man , Heuzé Céline , Ickes Luisa , Zhou Lu
Published: March 2024

Polynyas, open water regions within the sea ice cover, have been observed by satellites intermittently in the Arctic region over the past few decades. Their formation is complex, requiring various drivers to precondition and trigger the opening, which then influences local and regional weather significantly. Therefore, understanding Arctic polynyas’ spatial and temporal distribution is crucial to studying the polynyas’ impacts on climate. To date, most research is local and short-term, focusing on the major active Arctic polynyas or specific events; there is a need for pan-Arctic, long-term studies of all polynyas. Here, we use all available sea ice satellite data products to investigate all Arctic polynya events since 1979, in particular their locations for each day. The location preciseness and robustness are examined by sensitivity tests, varying the sea ice concentration (20 – 40%) and thickness (10 – 30 cm) thresholds. In the meantime, polynyas’ daily area extent, event duration, and recurrence are also obtained. The results indicate that the Franz-Josef Land, Eastern Kara Sea, and Nares Strait are the most active polynya formation-prone regions during wintertime. In addition, there is an increasing trend of polynya formation across the observation period. In future work, we plan to use the retrieved locations to determine whether thermodynamics or dynamic forcings contribute most to the Arctic polynyas’ opening.
Quantifying cross-scale hydrodynamic effects of root ecophysiology
Authors: Bouda Martin , Vanderborght Jan , Couvreur Valentin , Šípek Václav , Javaux Mathieu
Published: March 2024

Mechanistic representation of soil-root hydrodynamics is necessary to make robust predictions of canopy fluxes (transpiration, photosynthesis) under water limitation. Soil water limitation can arise at a range of characteristic scales down to millimetres but its effects can be felt across entire landscapes. This mismatch between the scales of cause and effect makes representing water limitation a central challenge in Earth System Models (ESM) and a key source of uncertainty in the terrestrial carbon cycle. We aim to unify the description of soil-root water flows across scales to bridge this gap and to demonstrate cross-scale effects of root ecophysiological mechanisms on the water and carbon cycles.We developed a new model formulation from analytical solutions to the differential equations for flows on root networks. By formulating the integrals in terms of mean water potentials over arbitrary root segments, we obtain a linear system directly without introducing a numerical approximation. Partial Gaussian elimination then yields a system of exact equations for mean water potentials in the absorbing roots at any chosen scale.The upscaled equations reproduce exact solutions for water potentials and flows on a single plant at any scale under set boundary conditions. Fitted to explicit stand-scale simulations, the model shows non-increasing error with the addition of further plants to the explicit simulation set. Proof-of-concept results show improved agreement with field data during a seasonal drought over previous models. The computational cost of these calculations is lower or equal to methods present in ESM and other upscaling methods. Code for producing the upscaled equations for any root hydraulic architecture is available online for beta testing.We will use this model formulation to connect observations of plant hydrodynamic functioning across scales. We are currently collecting data on root growth, turnover, and soil-plant hydrodynamics at six instrumented forest sites. We will supplement these observations with lab-based measurements at root and plant scale. By using the model to bridge across the scales of observation, we expect to quantify the cross-scale effects of individual mechanisms, such as the effect of root phenology on the seasonal variation in land-atmosphere hydrodynamics. This will be an important step towards reducing uncertainties in the plant-mediated processes that link the terrestrial carbon and water cycles.
The thrust structure and slip partitioning of Haiyuan-Qilian systems at NE margin of Tibetan plateau, constrained from geomorphic evidence 
Authors: Hu Xiu , Wang Yiran
Published: March 2024

Faulting and folding of basement rocks together accommodate convergence within continental orogens. Here we use the river terraces sequences along the Dongda river as the geomorphic tracer to examine deformation patterns at the northeastern Qilian Shan. Five river terraces, T1 (youngest), T2, T3, T4a and T4b (oldest), were identified and dated as 4.2 ± 0.3 ka, 6.1 ± 0.5 ka, 12.4 ± 2.5 ka, 16.4 ± 0.2 ka and 27.4 ± 2.5 ka, respectively. Three major reverse faults, Minle-Damaying fault, Huangcheng-Ta’erzhuang fault, and Fengle fault, contribute to deformation of the region. Based on displaced terrace treads, we estimated the vertical slip rate along the Minle-Damaying fault as 0.7–1.2 mm/a, along Fengle fault as 0.5–0.7 mm/a. Apart from surface displacement across faults, folding of the Dahuang Shan anticline at the hangingwall of Fengle fault adds to an additional uplift rate of ~ 0.2 mm/a at its crest. Inhomogeneous uplift of the intermontane basins between Minle-Damaying fault and the Dahuang Shan anticline indicates a 0.9 ± 0.2 mm/a uplift rate along the Huangcheng-Ta’erzhuang fault. Kinematic modeling shows that the deformation propagated from North Qilian to the foreland along a south-dipping 10° décollement which rooted Haiyuan fault at the depth of 20–25 km, accommodating 2.7–3.8 mm/a total crustal shortening rate. We suggest that the thrusts formed and high strain rate at eastern Qilian as a results of strain partitioning within the Haiyuan-Qilian systems, might coincided with the restraining bend of Haiyuan fault system, and strain rate within this complex structure may bear high regional seismic hazard.
Transport of ammonium nitrate and organic aerosol into the extratropical stratosphere associated with the Asian monsoon outflow
Authors: Ekinci Fatih , Köllner Franziska , Eppers Oliver , Appel Oliver , Brauner Philipp , Dragoneas Antonis , Molleker Sergej , Lauther Valentin , Volk C. Michael , Hoor Peter , Schneider Johannes , Borrmann Stephan
Published: March 2024

The Asian Monsoon Anticyclone (AMA) is of global importance because of its role in transporting pollutants over long distances through dynamic processes such as eddy shedding. Its impact extends beyond the Asian region to Europe and North America. To study the composition of the extratropical Upper Troposphere and Lower Stratosphere (UTLS) under the influence of the export of AMA air masses, airborne measurements were conducted on board the research aircraft HALO from Anchorage (Alaska) in August/September 2023.Our instrument ERICA (ERC Instrument for the Chemical composition of Aerosols) was a part of this mission, with the objective to analyze the chemical composition of particles in the outflow region of the AMA. ERICA combines the aerosol mass spectrometer ERICA-AMS, which is designed for bulk measurements of aerosol particles, and the single-particle mass spectrometer ERICA-LAMS.The objective of our study was to determine whether aerosol particles are transported from the AMA into the extratropical UTLS region. Measurements of methane and dichloromethane were employed to identify air masses originating from the AMA. To distinguish between the tropospheric and stratospheric air masses, ozone and nitrous oxide were utilized. Our results demonstrate that UTLS air masses exhibit elevated concentrations of ammonium, nitrate and organic matter based on ERICA-AMS data, along with enhanced methane and dichloromethane mixing ratios. These results are consistent with previous high-altitude measurements in the center of the AMA, showing the presence of enhanced ammonium nitrate and organic particle concentrations (Appel et al., 2022). These findings lead to the conclusion that particles from the AMA were transported from the center of the AMA into the extratropical UTLS region. Initial data analysis suggests a quasi-horizontal isentropic transport of these particles from subtropical to extratropical regions.