bluuebunny/crossref_metadata_2025 huggingface dataset:
Blended LEO-GEO Tropospheric Column NO2 for Air Quality Applications
Authors: Wei Zigang , Kondragunta Shobha , Yang Kai
Published: March 2024

With the launch of Tropospheric Emissions: Monitoring of Pollution (TEMPO) and Geostationary Environment Monitoring System (GEMS) instruments in geostationary (GEO) orbit, we are entering a new era of air quality monitoring.  These hourly observations of trace gases and aerosols need to be thoroughly evaluated for the time of the day biases that stem from solar-satellite viewing conditions.  Because observations made from low earth orbit (LEO) satellite sensors such as TROPOspheric Monitoring Instrument (TROPOMI) and Ozone Mapping and Profiler Suite (OMPS) are well characterized, comparisons can be made to understand viewing geometry dependent biases in GEMS and TEMPO retrievals and develop soft calibration methods.  We developed a Kalman filter approach that combines tropospheric nitrogen dioxide column (tropNO2) data from TROPOMI and GEMS. The spatial and temporal variability in tropNO2 comes from GEMS whereas TROPOMI tropNO2 observations are added to the Kalman filter process as observations that nudge GEMS tropNO2.  The relative weighting is influenced by the observation error covariance from GEMS and TROPOMI. Analysis of the GEMS tropNO2 data reveals its systematic biases, while applying the Kalman filter method to merge the GEMS and TROPOMI will yield a more accurate NO2 product. Accuracy of the merged tropNO2 data is determined by comparing the merged dataset against ground-based measurements from the Pandonia Global Network. We will present the methodology and case studies application of the merged dataset.
Likely accelerated weakening of Atlantic overturning circulation emerges in optimal salinity fingerprint
Authors: Zhu Chenyu , Liu Zhengyu , Zhang Shaoqing , Wu Lixin
Published: March 2024

The long-term response of the Atlantic meridional overturning circulation (AMOC) to anthropogenic forcing has been difficult to detect from the short direct measurements available due to strong interdecadal variability. Here, we present observational and modeling evidence for a likely accelerated weakening of the AMOC since the 1980s under the combined forcing of anthropogenic greenhouse gases and aerosols. This likely accelerated AMOC weakening signal can be detected in the AMOC fingerprint of salinity pileup remotely in the South Atlantic, but not in the classic warming hole fingerprint locally in the North Atlantic, because the latter is contaminated by the “noise” of interdecadal variability. Our optimal salinity fingerprint retains much of the signal of the long-term AMOC trend response to anthropogenic forcing, while dynamically filtering out shorter climate variability. Given the ongoing anthropogenic forcing, our study indicates a potential further acceleration of AMOC weakening with associated climate impacts in the coming decades.
Combining crowdsourced weather data and the numerical urban climate model PALM – potentials and limitations
Authors: van der Linden Lara , Hogan Patrick , Maronga Björn , Hagemann Rowell , Bechtel Benjamin
Published: March 2024

The increasing intensity and frequency of heat waves combined with the urban heat island can create thermal conditions which are hazardous for human health. Numerical urban climate modelling can deliver the necessary information to plan resilient adaptation measures for healthy living conditions in cities under a future climate. However, as a model is always a simplification of the real world, model evaluation with measurement data is important. Traditional measurement networks and campaigns are very often not suitable in active planning processes. Crowdsourcing the required weather data offers the potential to easily evaluate model results at any given time.To identify the potentials and limitations of this approach, the microscale urban climate model PALM is applied to simulate a hot day (Tmax > 30 °C) in a German city. The model results are evaluated with quality controlled crowdsourced air temperature data. The evaluation reveals a good model performance with a high coefficient of determination (R2) of 0.86 to 0.88 and a root mean squared error (RMSE) around 2 K. A temporal pattern in model accuracy is detected with an underestimation of night-time air temperatures. Due to the high number of available stations and the resulting representation of intra-urban temperature variations, the crowdsourced air temperature data proved valuable for model evaluation. Limitations for this approach arise from radiation errors leading to a reduced data quality. Furthermore, measurements from a single station are influenced by microscale and localscale conditions and therefore only the information derived from several stations can be used for evaluation.
Crustal modification influenced by multiple convergent systems: Insights from Mesozoic magmatism in northeastern China
Authors: Huang He , Wang Tao , Guo Lei
Published: March 2024

Convergent continental margins are the major sites for the formation, differentiation, preservation, and destruction of continental crust. This article focuses on the Mesozoic crustal modification history of northeastern China from a magmatic perspective. During Mesozoic times, NE China was influenced by three convergent systems, namely the Paleo-Asian Ocean (PAO) regime to the south, the Mongol-Okhotsk Ocean (MOO) regime to the northwest, and the Paleo-Pacific Ocean (PPO) regime to the east. This study comprehensively synthesizes information on Early Triassic to Early Cretaceous magmatic rocks. We unravel the spatiotemporal effects of the above-mentioned convergent regimes by evaluating the migration of major magmatic belts and other geological and geophysical evidence. The PAO regime is confined to the southernmost part of NE China and exerted influence during pre-late Late Triassic times. The MOO regime-related magmatism lasted until the early Early Cretaceous and occurred throughout the Great Xing’an Range and adjacent regions. The spatial effect of the PPO did not exceed the eastern margin of the Songliao Basin until the Early Jurassic; low-angle to flat subduction of the PPO slab led to the westward migration of continental arc front in the Middle Jurassic and the waning of PPO regime-related magmatism in the Late Jurassic. Since the earliest Cretaceous, the rollback and retreat of the PPO slab became the predominant geodynamic control in NE China, but the superposition of the MOO regime played a role during the early Early Cretaceous. Employing whole-rock Nd and zircon Hf isotope spatial imaging, this study elucidates that, although the pre-Mesozoic lithospheric heterogeneity provides first-order control, the Mesozoic crustal architecture of NE China was further carved by Mesozoic tectonics. Retreating subduction (slab rollback) and post-collisional lithospheric delamination resulted in the prolonged extensional background and crustal growth (rejuvenation); on the contrary, low-angle subduction and syn-collisional compression could cause transient periods of ancient crust reworking. Our results also estimate the high altitude of the Great Xing’an Range and adjacent regions in the Early Cretaceous. This study opens new possibilities to explicitly document crustal modification processes in fossil orogens from a magmatic perspective.
Quantifying economic impact of tropical climate variability: From past to future
Authors: Liu Yi , Cai Wenju , Lin Xiaopei , Li Ziguang , Zhang Ying , Newth David
Published: March 2024

The El Niño-Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) are the most prominent tropical climate variability affecting extreme weathers often with largescale socioeconomic impacts on global countries. Elusive are issues to what extent the impact affects the macroeconomy, how long the impact lasts, and how the impact may change in a warming climate. Using a smooth nonlinear climate-economy model fitted with historical data, here we find a damaging impact from El Niño and pIOD which increases for a further several years after initial shock. We attribute a loss of trillions and hundreds of billions US dollars globally for extreme El Niño and pIOD, which are far greater than previous estimates based on tangible losses. We find impacts from La Niña and nIOD are asymmetric and weaker. Under climate change, economic loss grows exponentially with increased ENSO and IOD variability. Exacerbated economic damage from changing ENSO and IOD should be considered in assessments of international mitigation strategies.
Modeling and future prediction of spring phenology in grassland on the Qinghai-Tibetan Plateau
Authors: Wang Lei , Zhao Xinyi , Yin Haobo , Zhu Guoying
Published: March 2024

The Qinghai-Tibet Plateau (QTP) is an important ecological barrier in China and even East Asia, and its main vegetation cover type is grassland. With the global climate change, the phenological period of grassland on the QTP is constantly changing, which affects the climate and ecosystem through carbon cycle, hydrothermal cycle, etc. The influencing factors of phenology and its future change trend have become the key issues. In this paper, the spring phenological model of the QTP grassland was constructed by using the start of growing season (SOS) extracted from MODIS NDVI, air temperature and soil moisture data from 2000 to 2020. Combined with CMIP6 climate data, the future phenological changes of the QTP grassland under the SSP245 scenario were predicted. The results showed that: (1) The cumulative temperature and cumulative soil water threshold model was effective in simulating spring phenology of grassland on the QTP, and the root-mean-square error was only about 8 days. (2) The climatic thresholds at SOS of different vegetation types are closely related to their spatial distribution locations. Vegetation growth in the eastern and southern parts of the QTP requires higher hydrothermal conditions. (3) The QTP showed an overall warming and wetting trend in the future, with greater changes in the first half of the 21st century than those in the second half of the 21st century. (4) The advance of SOS in the northwest grassland was significantly higher than that in the southeast grassland. By the end of the 21st century, most grasslands on the QTP began to grow before mid-June.
Hyperspectral Remote Sensing of Saline Soils in Arid and Semi-Arid Environments
Authors: Abuelgasim Abdelgadir , Aldhaheri Alya
Published: March 2024

Remote sensing of saline soils has been an active area of research in the past few decades. This is particularly so as soil salinity is a major environmental geo-hazard in both agricultural lands and arid and semi-arid regions. Saline soil adversely affect soil and play a major role in soil erosion, dispersion and degradation. Furthermore, saline soils in arid and semi-arid regions lead, in certain situations, to land subsidence, and ground upheaval. In agricultural lands saline soils lead to reduced agricultural productivity, interference with plant nutrition and soil erosion.Mapping saline soils is carried out using various techniques and procedures ranging from direct field observations and sampling to space based remote sensing techniques. Traditional methods of measuring soil salinity are time-consuming and labor intensive, making remote sensing techniques an attractive alternative. Remote sensing provides a less costly procedure due to the large global spatial coverage, continuous repetitive coverage and high-quality earth observations. Most of the remote sensing of saline soils previous research have focused on the broad band remote sensing part with primary focus on the spectral ranges in the near infra-red and the short-wave infra-red. However, higher levels of detection accuracy has not been widely achieved.In comparison to broad band remote sensing data, hyperspectral remotely sensed data provides an alternative approach that is much more accurate in detection levels of saline soils and their spatial distribution. This research employed a hand-held hyperspectral sensor specifically the SVC-XHR-1024i to collect reflectance data over various samples of soils collected in western United Arab Emirates. The collected data were then processed to derive spectral indices that are sensitive to soil salinity. Laboratory measurements of electrical conductivity (EC) of soil water extracts were carried out for the corresponding soil samples. The study established a statistical relationship between measured soil hyperspectral reflectance and EC salinity values. The study findings indicate that the spectral ranges in the shortwave infrared (SWIR) and near-infrared (NIR) are crucial and optimal in detecting soil salinity, in comparison to any other spectral ranges. An accuracy of 71% in detecting saline soils, including salt flats, was achieved through the use of narrow band hyperspectral data at the SWIR and NIR ranges. This by far exceeds accuracy levels that were previously achieved using broad band remote sensing data. The study also, highlights the potential of hyperspectral remote sensing as a cost-effective and efficient tool for monitoring soil salinity and identifying areas at risk of salinization, which can inform land management strategies for sustainable agriculture and future land development.
Dynamic recrystallization of olivine during simple shear: evolution of microstructure and crystallographic preferred orientation from full-field numerical simulations
Authors: Yu Yuanchao , Llorens Maria-Gema , Griera Albert , Gomez-Rivas Enrique , Bons Paul D. , Garcia-Castellanos Daniel , Hao Baoqin , Lebensohn Ricardo A.
Published: March 2024

The deformation of the upper mantle is predominantly governed by the mechanical behavior of olivine (Karato et al., 1989). During mantle flow, olivine undergoes crystal-plastic deformation, leading to the development of crystallographic preferred orientations (CPOs). In this process, the a-axes of olivine polycrystalline aggregates align with the flow direction (Hansen et al., 2012). Consequently, the observed CPOs in olivine-rich rocks serves as an indicator of the mantle flow direction. While the influence of plastic deformation is well understood, the role of dynamic recrystallization during deformation remains not fully comprehended, hindering our ability to interpret the deformation history of naturally-deformed rocks.This contribution employs microdynamic numerical simulations of olivine polycrystalline aggregates with varying iron content (fayalite content) to explore the CPO and grain size response to dynamic recrystallization. Utilizing a full-field approach with explicit simulation of viscoplastic deformation (http://www.elle.ws; Bons et al., 2008; Piazolo et al., 2019) and dynamic recrystallization processes under simple shear boundary conditions up to high strain, this study indicates that simulations with only dislocation glide and also those including recrystallization successfully reproduce such steady state conditions, without requiring other potential mechanisms. The model establishes a framework for understanding the development of olivine CPOs in mantle rocks, highlighting the interplay between plastic deformation and dynamic recrystallization processes, including grain boundary migration, intracrystalline recovery, and new grain nucleation.Acknowledgements: Yuanchao Yu acknowledges funding by the China Scholarship Council for a PhD scholarship (CSC-202008130104). This work has been developed using the facilities of the Laboratory of Geodynamic Modelling of GEO3BCN-CSIC.
Late oligocene elevation of the Himalaya recorded by O and H isotopes of fluid inclusions
Authors: Melis Raphaël , Mahéo Gweltaz , Gardien Véronique , Leloup Philippe-Hervé , Scaillet Stéphane , Jame Patrick , Bonjour Erik
Published: March 2024

Since the Earth’s topography is shaped by both tectonic and climatic processes, measuring land surface elevation variations through time is of critical importance for the investigation of the multiple interactions between mountain building (orogenic) processes and long-term climate change. With a total surface area of over 5 million km2, an average elevation of 5000 m and 14 peaks over 8000 m, the Tibetan Plateau (TP) and adjacent Himalaya are particularly well suited to this research, as many models attempt to explain the growth of these high elevation regions in the context of the continental collision between India and Asia and their feedback on the Asian climate. However, the evolution of surface elevation (paleoaltimetry), whilst essential, is still elusive in the Himalaya. A number of published paleoaltimetric data hinges on the relationship between the stable isotopic composition of precipitation (δ18O and δD) and altitude. However, these methods, based on the stable isotopic composition of carbonates and phylosilicates, do not provide both δ18O and δD values and involve the use of an isotope exchange equation to calculate the composition of paleoprecipitation. To avoid such calculation, we use a method developed at LGL-TPE, which directly measure the isotopic composition (δ18O and δD) of paleoprecipitation trapped in fluid inclusions of hydrothermal quartz veins.We measured the δ18O and δD of fluid inclusions in quartz veins within the Main Central Thrust shear zone in the Jajarkot klippe (Central Himalaya, Nepal). The δ18O of fluid inclusions varies between -3.69‰ and -9.01‰ and the δD between -43.11‰ and -74.24‰, which are consistent with meteoric water compositions. Stable isotope analysis were coupled with Ar-Ar geochronology on hydrothermal white micas that co-crystallized with quartz and indicates an age of 24.7 ± 0.2 Ma for vein formation. Taken together, these data allow us to calculate a mean elevation of the Central Himalaya of 2771 +286/-403 m at the end of the Oligocene, a period for which no previous paleoaltimetric data are available. Although already significant 25 Myr ago, the mean elevation of the Central Himalaya was nevertheless lower than the average elevation of the present topography (~5000 m), which formed at least ~16 Myr ago (e.g., Gébelin et al., 2013, Melis et al., 2023). Collectively, our data as well as previous paleoaltimetric studies provide a valuable contribution to the assessment of deformation models for the Himalayan range. 
Biogeochemical feedback effects on future wetland methane emissions and implications for global mitigation
Authors: Shen Lu , Peng Shushi , Zhang Zhen , Tong Chuan , Lin Jintai , Li Yang , Zhong Huiru , Ma Shuang , Zhuang Minghao , Gauci Vincent
Published: March 2024

Natural wetlands account for one-third of global methane (CH4) emissions and so profoundly influence climate. However, existing estimates of future changes in CH4 usually neglect feedbacks associated with global biogeochemical cycles. Here, we employ data-driven approaches to estimate both current and future wetland emissions that consider the effects of changing meteorology and biogeochemical feedbacks arising from sulfate deposition and CO2 fertilization. We report intensified wetland emissions from 2000-2100, with biogeochemical effects explaining 30% of emissions growth by 2100. Our results suggest that 8-15% more aggressive cuts to anthropogenic methane emissions are needed if we are to stay within the Paris Agreement guardrails of 1.5°C warming.
Spatio-temporal characteristics of rainfall over different terrain features in the middle reaches of the Yangtze River basin during the warm seasons of 2016-202
Authors: Sun Jianhua , Wei Qian
Published: March 2024

Based on the hourly rain gauge data during May-September of 2016-2020, we analyze the spatio-temporal distributions of total rainfall (TR) and short-duration heavy rainfall (SDHR, hourly rainfall ≥ 20 mm) and their diurnal variations over the middle reaches of the Yangtze River basin. For all three types of terrains (i.e., mountain, foothill and plain), the amount of TR and SDHR both maximized in June/July, and the contribution of SDHR to TR (CST) peaked in August (amount: 23%; frequency: 1.74%). Foothill rainfall is characterized by a high TR amount and a high CST (in amount); mountain rainfall is characterized by a high TR frequency but a small CST (in amount); and plain rainfall shows a low TR amount and frequency, but a high CST (in amount). Overall, stations with high TR (amount and frequency) are mainly located in the mountains and foothills, while those with high SDHR (amount and frequency) are mainly concentrated in the foothills and plains close to mountainous areas. For all three types of terrains, diurnal variations of both TR and SDHR exhibit a double-peak (weak early morning and strong late afternoon) and a phase shift from the early-morning peak to the late-afternoon peak from May to August. Around the late afternoon peak, the amount and frequency of the SDHR in the foothills is larger than those of mountains and plains. The TR amount in the foothills increase significantly from midnight to afternoon, suggesting that thermal instability may play an important role in this process.
West African dust load modeling and its impact on solar radiation forecast during the dry season
Authors: Clauzel Léo , Anquetin Sandrine , Lavaysse Christophe , Siour Guillaume , Bergametti Gilles , Marticorena Béatrice , Bouet Christel , Lapere Rémy , Thomas Jennie
Published: March 2024

The expected growth of solar photovoltaic (PV) production in West Africa over the coming decades poses challenges to the electrical network requiring accurate solar forecasts for both energy producers and power grid managers. Furthermore, solar radiation is affected by dust aerosols which play a significant role in West African meteorology, due to the proximity of this region to the Sahara desert, which is the world's largest source of mineral dust aerosols emissions.In this general context, our research aims at identifying the impact of mineral dust on solar energy production. Thus, this study focuses on evaluating the influence of dust aerosols on solar radiation forecasts for the Zagtouli solar plant in Burkina Faso. Employing a coupled approach between a meteorological model (WRF) and a chemical transport model (CHIMERE), two dust events that are representative of the dry season are simulated in line with West African climatology. While one event is linked to dust emissions from the Bodélé plateau (Chad), the other is related to dust sources located within the South Atlas area.The model undergoes rigorous assessment in regards to dust life cycle parameters (Aerosol Optical Depth (AOD), PM10, size distribution) and variables essential for solar energy production (Global Horizontal Irradiance (GHI), temperature) using in-situ measurements from long-term observatories (AERONET, INDAAF, AMMA-CATCH) and from the solar farm (GHI), satellite observations (AQUA/TERRA-MODIS, CALIPSO-CALIOP), and reanalysis data (CAMS). This evaluation shows a robust performance of the model.In addition, sensitivity studies are implemented to evaluate the respective impacts of direct and indirect effects of dust aerosols on the amount of solar radiation available at the surface.Overall, this study provides strong support for a modeling approach that couples meteorological processes with the dust life cycle to refine solar forecasts in the West African region.
Current adjustment of the mean Earth ellipsoid parameters
Authors: Panou Georgios , Marti Urs
Published: March 2024

The need for the determination of the parameters of an equipotential rotational ellipsoid of revolution that approximates closer and closer to the Earth requires analysis of the most currently available data. The main objective of this study is to examine such new data and to perform an adjustment technique to estimate the parameters and their standard deviations of the mean Earth ellipsoid. The parameters considered are the geocentric gravitational constant, the angular velocity, the geoidal potential, the dynamical form factor, and the major and minor semi-axes. A-priori estimates of these quantities, which may be determined independently, are treated as “observations” and their adjusted values from a weighted least-squares procedure are presented. Since a level ellipsoid of revolution and its gravity field are completely determined by four constants, we use two non-linear condition equations to relate the six parameters for performing the adjustment. Among the products of the adjustment is the correlation matrix of the adjusted values of parameters, which helps us in the selection of a consistent set of four parameters for the definition of a new Geodetic Reference System (GRS). After the selection of the four parameters, we compute by Newton’s method the two derived parameters and estimate their standard deviations by applying the law of propagation of variances. Furthermore, all the derived geometric and physical constants are computed from the defining constants of a GRS, by means of closed formulas. Finally, in order to yield numerical results of high precision, all computations are executed in computer algebra system software using variable precision floating point numbers.
What do we really know about Historical Earthquakes in Australia?
Authors: Martin Stacey , Cummins Phil , Allen Trevor , Griffin Jonathan
Published: March 2024

Given the projected population and economic growth in urban and regional Australia over the coming decades, a robust knowledge of past seismicity must be required for modern seismic hazard assessments. This is important because it influences the recurrence rates used in seismic source-rate models needed to characterize ground-motion hazard. Together with observations from a short modern instrumental record and a growing paleoseismic dataset, information on past seismicity in Australia is gleaned from records of historical earthquakes since the start of European colonization in the late 18th century. As with any scientific data, such documentary evidence extracted from newspapers and other written materials is subject to uncertainties and is prone to the repetition of misinterpreted incomplete data stemming from the absence of a modern re-examination of primary sources. We address these issues by consulting primary documentary sources at Australian libraries and archives to construct a dataset of over 4,000 uniformly assessed macroseismic observations (felt shaking effects) for earthquakes since 1788. These uniformly assessed data have led to the identification of discrepancies in the historical catalogue such as in the locations of the 1897 Beachport, 1918 Queensland and the 1954 Adelaide earthquakes for which catalogued epicentral locations are inconsistent with their macroseismic intensity distributions, felt aftershocks, environmental effects, and reviewed instrumental observations. Our study highlights the benefit of the re-evaluation of underutilized pre-instrumental documentary source materials to homogenize both archival and seismological observations, with modern observations, and to quantify uncertainties that are geological, numeric or societal. This will in turn improve our understanding of historical earthquakes in Australia and will benefit future assessments of modern seismic hazard in the country. We note further that the need to document, interpret, and analyse such underutilised pre-instrumental documentary source materials is not restricted to the analysis of historical earthquakes alone, but is also of benefit to the evaluation of other natural hazards not only in Australia but also around the world.
The morphotectonic evolution of the Albanian Dinarides: new insights from the application of in situ and meteoric Be cosmogenic nuclides
Authors: Bazzucchi Chiara , Crosetto Silvia , Wittmann Hella , Ballato Paolo , Faccenna Claudio , Muceku Bardhyl , Rossetti Francesca
Published: March 2024

The Albanian Dinarides represent the central segment of the Dinarides–Hellenides orogenic belt. The Albanian sector is strategically located at the boundary between continental subduction to the north and oceanic subduction to the south, making it an ideal setting to explore the interplay between surface and deep geological processes. Furthermore, modern seismicity (e.g. 1979, Mw 7.1 Montenegro, and 2019, Mw 6.4 Durres earthquakes) and geomorphic features indicate ongoing tectonic activity at least since the late Quaternary. In this study, we explore the landscape response to tectonics and climate by 1) conducting an extensive geomorphic analysis including knickpoint extraction, ksn and chi analysis, longitudinal river profile projection, and mapping of geomorphic features such as windgaps, river terraces, pediment surfaces and uplifted relict landscapes, and 2) estimating basin-wide denudation rates using cosmogenic nuclides.Specifically, we collected river sediment samples from more than 20 rivers draining all tectonic units and we determined denudation rates using the classic in situ 10Be technique for catchments draining quartz-bearing lithologies, and the new meteoric 10Be/9Be technique in carbonate and ophiolite settings where quartz-poor lithologies predominate. In a few cases, we used both techniques on the same catchments for inter-method comparison. The geomorphic analysis highlights the presence of river terraces, non-lithological knickpoints, uplifted relict landscapes and wind gaps suggesting recent tectonic activity at both regional and local scales. This led to a reshaping of the river network with changes in the hydraulic connectivity with the regional sea level that altered the sediment transport directions. Furthermore, Quaternary climatic variations appear to play a crucial role in the erosive power of rivers and in controlling cycles of aggradation and incision.Denudation rates show spatial variability, ranging from less than 0.3 mm/yr to 0.9 mm/yr in the south, where carbonate and siliciclastic predominate, to over 1 mm/yr in the central part of Albania, where siliciclastic rocks and ophiolites are widely exposed. Although the rates present a good correlation with geomorphic metrics (e.g., ksn and hillslope), the observed variability appears to be influenced by local tectonic processes associated with active normal faults and salt diapirism. Overall, the denudation rates obtained with the two Be techniques are consistent and align with published incision rates derived from river terrace dating, suggesting coupling between fluvial incision and hillslope processes over the last few thousands of years. The consistency between the two cosmogenic Be methods validates the high future potential of the meteoric 10Be technique in quantifying denudation rates in settings dominated by non-quartz lithologies.
A deep learning model-based reconstruction of Landsat NDVI and its application for vegetation phenology monitoring
Authors: Song Zijie , He Tao
Published: March 2024

High quality Normalized Difference Vegetation Index (NDVI) time series data are important for regional and global ecological applications. However, missing observations in cloudy and shaded areas in current high-resolution satellite data severely limit their use. Traditional temporal filtering reconstruction methods are easily affected by frequent fluctuations, large data gaps and irregular noise in the observations. Meanwhile, satellite images often lack complete and accurate real data as training sets, which limits deep learning-based reconstruction methods. To address these problems, this paper proposes a reconstruction method with Landsat-8 NDVI time-series images based on bidirectional long-short memory networks (Bi-LSTM). The core of the method is a sequence-to-sequence time series reconstruction model using Bi-LSTM as an encoder, decoder, and additionally adding a mask layer to locate irregular gaps in the time series data. To train the model, a multi-scale continuous NDVI time series dataset was constructed using near-surface observations and satellite fused images. Simulation experiments were conducted in 48 areas covering PhenoCam sites in North America. The coefficient of determination (R2) between the simulation results of this method and the real observations reached 0.7024 with an absolute bias of -0.0080, which outperformed the filtering method both in predicting missing cloud-covered areas and in extracting key nodes for vegetation growth. This method is pre-trained on a large-scale ground sample dataset before fine-tuning the parameters for the scenarios, which can be easily and quickly applied to generate long-term continuous NDVI datasets at a large spatial scale. In addition, the analysis of the phenology monitoring in the experimental areas shows that the results extracted from the reconstructed results of this method is very close to the PhenoCam-measured values, which is significantly improved compared to the extraction results using original Landsat data only, and at the same time shows more spatial detail compared to the MODIS climate products. This indicates that the 30m gap-free NDVI time series is sufficient for analysis and understanding of climate dynamics in heterogeneous areas with multiple vegetation growth patterns, mixing plant components and microclimates variation, which are difficult to be identified by the coarse spatial resolution phenology product.
A novel new T-FACE research platform advancing climate change simulation in paddy fields
Authors: Zhu Chunwu
Published: March 2024

This paper introduces an innovative new research platform known as T-FACE (Temperature by Free-Air CO2 Enrichment) for climate change simulation developed by Chinese Academy of Sciences. This T-FACE enables the simulation of future climate scenarios, specifically focusing on the interaction between high CO2 levels and warming within the paddy fields. The elevated CO2 treatment involves maintaining ambient CO2 levels in addition to an increase of 200 ppm, and the elevated temperature treatment includes a 2℃ rise in whole-ecosystem warming (air, water and soil surface temperature increase) compared to ambient conditions. The level of precision and stability achieved in the treatment control is of the first-class level. This is the first platform to explore the interaction between elevated CO2 and whole-ecosystem warming in open ecosystems. It can provide climate change simulation conditions for crop science, soil science, plant nutrition, ecology, environmental science and other related fields. This enables the study of how farmland systems respond, adapt to and address climate change.
Deriving long-term continous 30-m resolution surface albedo over Greenland based on Landsat data and preliminary accuracy evaluation
Authors: Fan Chao , He Tao
Published: March 2024

Surface albedo is one of the important climate variables that plays a key role in regulating the absorption of solar radiation available for melting over the Greenland Ice Sheet (GrIS). There is an increasing need for albedo data to be available for use in applications that require a medium to fine spatial resolution, such as GrIS melting changes. The different sensor characteristics and the active lifespan of the associated satellite result in the inherent limitations of the existing satellite albedo products, namely, coarse spatial resolution or short effective data time span. In earlier studies, the direct estimation method was applied to Landsat data for albedo estimations, which has been widely demonstrated to have high accuracy. However, due to the data collection frequency (16-day), cloud coverage (about 57% missing data caused by cloud coverage), and instrument failure (approximately 22% of the normal scene area missing in an SLC-off image), continuous data gaps often occur in Landsat observations. This paper proposed a spatiotemporal shape matching method to generate spatiotemporally continuous surface albedo data at a spatial resolution of 30m for snow surfaces. Validation results show that this algorithm can effectively fill the data gaps, in addition, it can be extended to the pre-MODIS era. Almost all the missing data resulting from cloud cover and instrument failure can be filled. And the temporal resolution of the fused Landsat albedo is 8-day. The fused Landsat albedo was demonstrated good accuracy with an R2 of greater than 0.8 and a RMSE of less than 0.075 against ground observations, which is comparable to the accuracy of the MODIS albedo product. By analyzing long-term albedo changes on the pixel level over the automatic weather stations operated by the Programme for Monitoring of the Greenland Ice Sheet (PROMICE), we found that the albedo of most sites was abnormally low in 1995, 1998, 2010, 2012, and 2019, indicating that large-scale GrIS melting occurred in these years. In addition, the variations in surface albedo over PROMICE stations exhibit geographic variability.
The Role of Interdisciplinary PBL Activities: Climate of the Past
Authors: Correia Nuno , Neves Vanessa , Gandra Alexandre
Published: March 2024

Nowadays, in Portugal, the challenge of Natural Sciences (NS) for middle and high school teachers is to make science education more attractive to young students. One way to achieve that is through practical work. Unfortunately, this kind of work is not very common in geology teaching. The Curricular Autonomy and Flexibility Project (DACP) with Biology/Geology, Mathematics and Physical/Chemistry was intended to increase the quality of teaching and learning, based on the Students Profile at Completion of Compulsory Education reference document and the guiding documents for Essential Learnings, which will provide help in the planning and assessment of teaching and learning.This work is an example carried out through the interaction of different learning environments, inside the classroom, and outdoors, and of different types of practical work, namely laboratory and fieldwork.  The organisation of the activities followed a pattern: the field trip to the Valongo Anticline (North of Portugal) and Problem-Based Learning (PBL).The Valongo Anticline allows  the observation of evolution of life during the Paleozoic, based on animal and plant fossils, as well as the possibility of dating the strata from the fossils they contain. It also presents some particular lithology evidence, namely the presence of icebergs, the existence of submarine volcanism, and the presence of beaches. The tectonic action is evidenced by the existence of folds and faults.The Problem Question (PQ) was based on an outcrop from the Paleozoic where we have the geo-trails that cover rocks of different ages of the region of Valongo. In this site it is possible to observe the variation in sedimentation environments (marine and continental) from nearly 540 to 300 M.y. Also, in this region we can find several outcrops with diamictites beds.  This   glaciomarine record of the Hirnantian (end-Ordovician) glaciation is evidence of the climate changes that occurred over Earth's history.  In this poster we discuss some ideas about what students learn from different activities and which other factors influence their learning process as students. The idea of interdisciplinary learning is to allow students to realize that certain fundamental concepts don’t belong to a single science subject. On the contrary, these concepts can be applied in many subjects.In conclusion, this poster presents some formal and non-formal educational practical activities that the students developed, in groups, during the year 2023 and 2024 and that can be used in the teaching of geology. 
Potential Field Line Resonances in Ganymede’s Magnetosphere Observed by Juno
Authors: Martos Yasmina M , Romanelli Norberto , Espley Jared R. , Connerney Jack E. P. , James Matthew , Kotsiaros Stavros
Published: March 2024

On June 7, 2021 Juno performed a close flyby of Ganymede, providing a unique opportunity to improve the current understanding of the magnetosphere. Here, we study the high-resolution (64 Hz signal) magnetic field spectrum employing three different approaches: 1) analysis of a ~3.5 minute near Juno’s closest flyby to the moon, 2) analysis of 12 sliding windows of ~2 min in this period and, and 3) analysis of a ~63 s window selected based on the dominant frequencies observed in the evolutionary spectra of the entire flyby. A fundamental period of ~16 s is observed in all three methods. In the specific case of the spectrum of the 63 s window, this shows a harmonic structure which could potentially be related to the frequencies associated with resonances of a dipole field. If this were the case, we estimate that the plasma density near the equator at 1.685 RG (selected L-shell) is equal to 22 amu/cm3, a much lower value than the local density of the plasma sheet near Ganymede (~100 amu/cm3). These two aspects may indicate that Juno crossed closed magnetic field lines of Ganymede’s magnetosphere for a short period of time only, if at all.
Complex Dynamics of Human Migration: Beyond Linear Thinking
Authors: Oh Woi Sok
Published: March 2024

Somalia is one of the countries suffering from severe environmental and socio-political situations without well-operating state power. Such conditions lead to huge population movements within the country. While many researchers attempted to understand these movements, conventional approaches (e.g., econometric modeling, logistic regression) are restricted to fully capture the underlying mechanisms of migration. Alternatively, I use multiple analytical techniques from complex systems science, including network analysis and modeling, event coincidence analysis, and causality detection. First, systematic network patterns are observed throughout multiple years. Transitive movements, which involve both direct and indirect movements via transit to migrate from an origin to a destination, clearly exist in internal displacement networks regardless of the driver (e.g., conflict or drought). Second, migration timings follow either bursty or Poisson dynamics depending on the external forces. If a district is not highly affected by external forces, migration timings in the district are likely to follow bursty dynamics due to self-organization. In the opposite case, Poisson processes work better. Third, external stressors drive migration differently in dry and rainy seasons. While the effects of socio-political and environmental drivers vary, network effects exist regardless of the season. Lastly, cascading behaviors are found, making migration decisions to be collective behaviors. Thus, a shock may propagate and lead to migration decisions in a remote place. These are just a few examples of the complex and higher-ordered dynamics of human migration. To grasp the full picture of human migration, more works beyond linear thinking are required in the future.
Machine-Learning-Based Ground Motion Models for Crustal and Subduction Zones of West Java, Indonesia
Authors: Rachmadan Andy , Kaka SanLinn
Published: March 2024

This study presents Ground-motion Models developed to predict Peak Ground Acceleration (PGA), Peak Ground Velocity (PGV), and 5% damped pseudo-spectral acceleration (PSA) at periods of 0.3, 1, and 3 seconds in West Java, Indonesia. The models consider Moment Magnitude, Epicentral Distance, Depth, and Soil site condition. We develop comprehensive ground motion models using three machine-learning techniques—Artificial Neural Network (ANN), Random Forest (RF), and Extreme Gradient Boosting (XGB) for the study area. The dataset comprises 2016 ground motions recorded at 60 stations during 211 earthquakes, including the notable M 5.6 Cianjur events. To assess model performance, we utilize evaluation metrics such as coefficient of determination (R2), root mean square error (RMSE), mean absolute error (MAE), standard deviation of residuals, and between-event and within-event residuals. Comparative analysis reveals the superiority of the three machine learning models over the classical regression approach, with Random Forest exhibiting the most robust performance. The best model is effectively applied to recent earthquakes, providing accurate predictions at various stations. These models will be valuable for updating seismic hazard analyses and contributing as inputs in developing an earthquake early warning system in this region.
Comprehensive evaluation of soil heavy metal distribution characteristics and soil quality in coalfield fire area
Authors: Hao Ruirui , Zeng Qiang
Published: March 2024

In this study, the soil physical and chemical properties and the distribution of heavy metals in the coalfield fire area were analyzed and evaluated, and the soil environmental quality in the coalfield fire area was comprehensively evaluated, so as to provide a theoretical and scientific basis for the comprehensive management of soil environmental quality in the coalfield fire area of Xinjiang. The pH、SOM,、TN、TP、K+、Ca2+、Na+、Mg2+、CO32-、HCO3-、Cl- 、SO42-and total heavy metals Pb、Ni、Cd、Cr、Cu、Zn、As、Hg were measured. The results showed that the average values of Pb, Ni, Cd, Cr, Cu, Zn, As and Hg were 17.24, 29.08, 0.18, 62.67, 34.68, 83.38, 8.45 and 0.06 mg/kg, respectively. The maximum exceedance multiple of Hg element was 10.15 times, the number of points exceeding the standard was 37, the point over-standard rate was 90.20%, and the average over-standard multiple was 1.78. There were 2 soil samples with a single factor pollution index of 0.7-1, which belonged to the alarmed soil, and 39 soil samples with a single factor pollution index of 1-2, which belonged to the lightly polluted soil, and the proportion of the alert soil and the lightly polluted soil were 4.88% and 95.12%.
The Evaporation Paradox in India
Authors: Saha Aniruddha , Jain Manoj Kumar
Published: March 2024

Evapotranspiration is pivotal in the hydrological cycle, significantly influencing agricultural practices, water balance and irrigation. An increase in reference evapotranspiration (ETo) is anticipated because of global warming; however, a decrease in pan evaporation/reference evapotranspiration is observed in various regions worldwide– known as the “evaporation paradox”. We study the existence of the evaporation paradox in India from 1990 to 2020 using data from 87 ground stations spanning across various climatic zones and its causative factors. Out of the four climatic drivers influencing ETo – solar radiation, wind speed, relative humidity, and air temperature; solar radiation was the major contributing factor leading to a decline of ETo over India. The reason being - ETo was observed to be highly sensitive to solar radiation, along with a decreasing trend of solar radiation (or sunshine hours). A seasonal analysis of the contributions analysis shows that - solar radiation is the major contributor in winter (Dec-Feb) and post-monsoon season (Oct-Nov) and the second major contributor after relative humidity during the summer season (Mar-May), all leading to a decline in ETo. During the monsoon (June-Sept), solar radiation does contribute to the declining trend of ETo. However, wind speed and vapour pressure are the major contributors during the monsoon season. Global dimming, which prevailed from the 1950s until late 1980 in most parts of the world, continues to persist over India without any signs of abating.