bluuebunny/crossref_metadata_2025 huggingface dataset:
Increases in extreme power shortage events of wind-solar supply systems worldwide
Authors: Zheng Dongsheng , Tong Dan , Davis Steven J. , Qin Yue , Liu Yang , Xu Rongchong , Yang Jin , Yan Xizhe , Zhang Qiang
Published: March 2024

Extreme power shortage events, especially occurred in wind-solar hybrid supply systems, are longstanding serious threats to safeguard energy security and socioeconomic stabilization. Here, 43 years of hourly reanalysis climatological data are leveraged to examine historical trends in defined extreme long-duration and low-reliability events in wind-solar systems worldwide. We find interannual and decadal uptrends in the two types of defined extreme power shortage events regardless of their frequency, duration, and intensity since 1980. For instance, duration of extreme low-reliability events worldwide has increased by 5.39 hours (0.113 hours y−1 on average) between 1980–2000 and 2001–2022. However, such ascending trends are unevenly distributed worldwide, with a higher variability in low- and middle-latitude developing countries but a smaller change in high-latitude developed countries. This observed uptrends in extreme power shortage events are primarily driven by increases in extremely low wind speeds instead of solar radiation. However, the changes in power shortage events and extremely low wind speeds are strongly disproportionated. Only 8.80% change in extremely low wind speed gives rise to over 30% variability in extreme power shortage events, despite a mere 1.26% change in average wind speed. Our findings underline that wind-solar hybrid supply systems will probably suffer from weakened power security if such upwards trends persist in a warmer coming future.
The sudden and prolonged Mesoamerican megadrought (1400-1600 CE) during the early LIA
Authors: Winter Amos , Zanchettin Davide , Warken Sophie , Lachniet Matthew , Rubino Angelo , Burnett Allison , Cheng Hai , Jury Mark , Miller Thomas
Published: March 2024

The Little Ice Age (LIA) was a predominant anomalously cold event on Earth that occurred from c. 1350 to c. 1850 with a near-global signature.  Many records from different paleo archives located throughout the greater Caribbean show hydroclimate heterogeneity throughout all or part of this period. Here we present new evidence from the Guatemalan stalagmite GU-Xi-1 that contains a prolonged period of persistently heavy oxygen isotope values indicating a long-term major dry event (MDE) which started rather abruptly around 1400 CE and lasted for about approximately 200 years (age uncertainty c.50 years), with both onset and termination likely occurring within a couple of decades. The age model and hence, the timing of the Xibalba MDE is regarded as robust because they are consistent with a change in calcite precipitation that produced the “L” layer in the Xibalba speleothem.  This layer which is associated with drying in speleothems could be precisely dated and bracketed using U/Th.  In this contribution, we present the Gu-Xi-1 record and discuss possible mechanisms underlying the reconstructed Mesoamerican megadrought and their connection with natural climate forcing agents active in the period.
Citizen-science approach to long-term observation of aquifer response to meteorological forcings
Authors: Hayashi Masaki , Uddin Md Shihab
Published: March 2024

Groundwater provides more stable source of water supply, compared to surface water, in the areas that experience large fluctuations in dry/wet condition, such as semi-arid, continental regions of Africa, Asia, and Americas. These regions are characterized by decadal-scale variability in precipitation, which translates into variability in groundwater recharge rates. Depending on the balance between precipitation and evapotranspiration, these regions can have several consecutive years of no or little recharge, causing a substantial decline of aquifer storage. Therefore, it is important to have a dense network of observation wells to monitor the spatial and temporal variability in aquifer storage over a long term, particularly in regions with highly heterogeneous aquifers. Groundwater in a system of heterogeneous aquifers is disintegrated, meaning that a large number of wells are required to monitor the behavior of many individual aquifer units. This is in contrast to the surface water system integrated by the river network, which can be effectively monitored using a relatively small number of river-gauging stations. As an example, the Paskapoo Formation aquifer system in Alberta, Canada, consists of numerous small sandstone aquifer units encased in mudstone aquitards, resulting in highly heterogenous behavior of aquifer water levels over a distance of < 1000 m. A community-based groundwater monitoring network was initiated in the Rocky View County in 2007-2008 to monitor the response of the Paskapoo Formation aquifer to multi-decadal fluctuations in meteorological forcings. The county occupies ~4000 km2 of predominantly agricultural area under the semi-arid climate, where mean annual precipitation is 400-500 mm and annual potential evapotranspiration is 600-700 mm. A citizen-science approach is used, whereby community volunteers monitor their own wells and report their observation to university researchers. The groundwater monitoring network is part of a hydrological observatory including stream gauging stations and meteorological stations measuring precipitation and evapotranspiration fluxes. The long-term data collected at the observatory are used to demonstrate the effects of wet-dry cycles on soil moisture, groundwater storage, and stream flow; and to predict responses of aquifer storage to climate-change scenarios using numerical groundwater recharge models.
Seasonal prediction of typhoon track density using deep learning based on the CMIP datasets
Authors: Sun Yuan , Feng Zhihao , Zhong Wei , He Hongrang , Wang Shilin , Yao Yao , Zhang Yalan , Bai Zhongbao
Published: March 2024

Tropical cyclones (TCs) seriously threaten the safety of human life and property especially when approaching coast or making landfall. Robust, long-lead predictions are valuable for managing policy responses. However, despite decades of efforts, seasonal prediction of TCs remains a challenge. Here, we introduce a deep-learning prediction model to make skillful seasonal prediction of TC track density in the Western North Pacific (WNP) during the typhoon season, with a lead time up to four months. To overcome the limited availability of observational data, we use TC tracks from CMIP5 and CMIP6 climate models as the training data, followed by a transfer-learning method to train a fully convolutional neural network named SeaUnet. Through the deep-learning process (i.e., heat map analysis), SeaUnet identifies physically based precursors. We show that SeaUnet has a good performance for typhoon distribution, outperforming state-of-the-art dynamic systems. The success of SeaUnet indicates its potential for operational use.
The time of emergence of Arctic warming, wettening and sea ice melting
Authors: Bintanja Richard , Tsakali Nicoleta , Skyllas Nomikos , Kolbe Marlen
Published: March 2024

The strongly warming and wettening Arctic exhibits considerable temporal interannual and decadal variability. A conclusive transition point to a new climate state – the time of emergence (ToE) – occurs when the forced signal exceeds natural variability. Uncertainties in model-simulated climate trends and variability, as well as in methods, have thus far resulted in diverging estimates of Arctic ToE. Here we use a detailed, robust method applied to state-of-the-art climate model projections to show that in most seasons Arctic sea ice thickness emerges first (2038-2043), followed by surface air temperature (2037-2053) and sea ice cover (2050-2074). Since precipitation/rainfall variability is comparatively high, these variables emerge relatively late (after 2080). Autumn generally exhibits the earliest ToE-values due to strong sea ice retreat and associated warming and surface evaporation. Spatial variations in Arctic trends and variability cause ToE for temperature and sea ice thickness to emerge first in the Central Arctic, whereas for sea ice cover and rainfall this primarily occurs in the North Atlantic – Barents Sea region. Evidently, parts of the Arctic are close to entering a new climate state in terms of temperature and sea ice changes, with wide-ranging, long-term and possibly irreversible consequences for vulnerable Arctic ecosystems and human activities.
Study of Changes in the Ulan Buh Desert under the Dual Impacts of Natural and Anthropogenic
Authors: Yan Yujie , Cheng Yiben
Published: March 2024

The Ulan Buh Desert, as one of China's eight significant deserts, is situated in the country's northwestern region and encompasses a diverse array of landscapes, including various desert types, vegetation, water bodies, and other landforms. This diversity is crucial for the ecological integrity and safety of the Yellow River Basin. The desert is notably constrained by water availability, and there has been a notable expansion in the degree of human activities, particularly regarding agricultural development, in the area.Over the past 32 years, studies tracking the temporal and spatial variations of the Normalized Difference Vegetation Index (NDVI) in the Ulan Buh Desert have revealed a consistent increase in vegetative cover. Through the analysis of drivers such as climate change and human activity, it has been determined that temperature exhibits a positive correlation with NDVI, a relationship that has strengthened progressively over the years. Conversely, precipitation's influence on NDVI has been relatively insignificant. On the human activity front, contributions to NDVI changes have grown considerably, with such activities accounting for nearly a 50% increase in the vegetative index, suggesting that human interventions are increasingly aligning with ecological rehabilitation and positive environmental outcomes.By scrutinizing the ecological consequences of both natural processes and human endeavors on the Ulan Buh Desert, insights gleaned can offer actionable recommendations for ecological restoration efforts, ensuring the sustainable management and recovery of this vital region.
Future Projections of Marine Heatwaves in the Indian Ocean under Different Socioeconomic Pathways
Authors: Wijendra Naidhelage Dushantha Sandaruwan Jayarathna , Zhou Wen , Collins Matthew , E. Adeyeri Oluwafemi , Wang Xuan , Widana Arachchige Erandani Lakshani , Zekai Ni
Published: March 2024

Marine heatwaves (MHWs) are extended periods of abnormal warm sea surface temperature (SST) events that can have considerable impact on the marine ecosystems and associated services. Despite recent developments in studying MHWs in the Indian Ocean, our understanding of their future occurrence remains limited. Hence, this study is crucial to expanding our understanding of future MHWs in the region. We use observational data from the Optimal Interpolated Sea Surface Temperature analysis (OISSTv2) and daily SST data from 14 models obtained from Coupled Model Intercomparison Project Phase 6 (CMIP6) to investigate the spatial and temporal characteristics of MHWs in the historical period (1982-2014) and future (2015-2100) under three shared socioeconomic pathways (SSPs, e.g., SSP126, SSP245, SSP585). During the historical period, more intense MHWs concentrated near the northern Arabian and Bay of Bengal region, with total MHW days of 20 ~ 25 days per year and mean intensity of 2 ~ 3 oC per year. The CMIP6 models overestimate the duration of MHWs while underestimating their intensity. Nevertheless, we employ the quantile delta mapping bias correction method to minimize these uncertainties in the CMIP6 multi model ensemble mean for a robust and reliable depiction of the future MHWs characteristics. We note accelerated positive trend in MHW metrics, including total days, and cumulative intensity, in the future compared to the historical period, resulting from global warming. Moreover, different emission scenarios exhibit different future MHWs characteristics. Specifically, the duration and mean intensity of MHWs are distinctly higher under SSP585 compare to other two scenarios, except for MHW frequency. Considering that we focused on a fixed baseline for MHW detection, we attribute the increase in MHWs duration to anthropogenic greenhouse gas emissions. Therefore, we emphasize the need for proactive measures to mitigate the impacts on future MHWs on marine ecosystems and associated services in the face of climate change. 
Enhanced subduction flux during the assembly of Pangea recorded by global intracontinental magmatism
Authors: Chen Qian , Liu He , Giuliani Andrea , Johnson Tim , Doucet Luc , Zhang Lipeng , Sun Weidong
Published: March 2024

Plate tectonics drives the compositional diversity of Earth’s convecting mantle through subduction of lithosphere. In this context, the role of evolving global geodynamics and plate (re)organisation on the spatial and temporal distribution of compositional heterogeneities in the convecting mantle is poorly understood. We test the hypothesis that an increase in the cumulative length of subduction zones associated with supercontinent assembly triggered geochemical enrichment of the convective mantle globally, in particular since the emergence of protracted, cold, deep subduction in the late Neoproterozoic. We compiled the trace element and Nd isotopic compositions of intracontinental basalts formed over the last billion years (1000 Myr).  After careful filtering to eliminate samples with evidence for crustal contamination, the data show that intracontinental basalts formed before 300 Ma exhibit supra-chondritic initial 144Nd/143Nd values. Those with sub-chondritic initial 144Nd/143Nd values become common only after 300 Ma, broadly coeval with the global appearance of kimberlites with geochemically enriched isotopic signatures. We attribute these step-changes in the sources of intraplate magmatism to a rapid increase in the supply of deeply subducted lithosphere due to increased peri-continental subduction during the assembly of Pangea.
Cold Pools in the Trades: External Drivers and Self-Organization Impact
Authors: Alinaghi Pouriya , Janssens Martin , Jansson Fredrik , Siebesma A. Pier , Glassmeier Franziska
Published: March 2024

Recent observations of the trades highlight the covariability between cold pool (CP) properties and cloud cover, suggesting a potential impact of CPs on the cloud radiative effect (CRE). To explore this, we use an ensemble of 103 large-domain, high-resolution, large-eddy simulations (Cloud Botany). We investigate the extent to which the variability in CPs is driven by external conditions or convective self-organization. Our findings show that CPs are notably controlled by large-scale conditions, specifically (horizontal) wind speed and subsidence. The temporal evolution of CPs is tightly related to the diurnality in radiation. To understand the extent to which CPs vary with self-organization, we switch off the diurnality in radiation. Despite the absence of the diurnal cycle, CP time series still exhibit fluctuations. These fluctuations result from the recharge-discharge of thermodynamic and dynamic properties of the sub-cloud layer owing to CP-cloud interactions. Our results demonstrate that circulations induced by CPs reinforce the parent clouds, resulting in deepening and scale growth, followed by mesoscale arcs enclosing clear-sky areas. Finally, we show that CPs influence CRE, but only when they exist during the day. Our findings emphasize the importance of the relationship between the timescales of self-organization and the diurnal cycle of external conditions, greatly influencing the CRE dependency on self-organizing CPs.
Monitoring long-term changes in NO2 pollution from global to city scale: A journey guided by environmental laws and policies
Authors: Kuttippurath Sai Amritha
Published: March 2024

Air pollution presents a formidable global challenge, exerting profound impacts on climate, human well-being and the world economy. Notably, atmospheric NO2, predominantly of anthropogenic origin, arises from diverse sources, including vehicular and industrial emissions. This study investigates the changes in global atmospheric NO2 through analysis of satellite and ground-based data, focusing on the period from 2002 to 2019. Elevated NO2 levels (> 8 × 1015 molec./cm2) are identified in regions such as the USA, Europe, India, China, the Middle East (MDE), South Africa (SA), Central Africa (CA) and selected regions in Brazil. Seasonal variability is evident, with peak concentrations in winter and troughs in summer, largely influenced by meteorological conditions and biomass burning. While NOx emissions from road transport dominate the USA and Europe, various industrial activities drive elevated NO2 levels in East China (EC), the Indo-Gangetic Plain (IGP) and SA. Noteworthy is the substantial decline (approximately -0.1 × 1015 molec./cm2/year) in NO2 observed in the USA and Europe during the study period. In contrast, significant positive trends (approximately 0.06–0.1 × 1015 molec./cm22/year) are noted in the MDE, EC, SA, CA and IGP. An additional analysis of NO₂ pollution in 3000 global cities reveals a declining trend in most cities in the USA and Western Europe (WE) at -0.1 × 1015 molec./cm2/year. Conversely, cities in India, China, Africa, Southeast Asia, MDE, and South America exhibit positive trends in NO2, ranging from 0.04 to 0.1 × 1015 molec./cm2/year. The decreasing NO2 trends in developed nations of North America and Europe are attributed to the enforcement of stringent vehicular norms, resulting in a significant reduction in road transport emissions. This study offers a comprehensive overview of recent NO2 pollution trends across nations and cities, highlighting the contrasting trajectories between developed and developing regions. It also suggests potential strategies for developing nations to mitigate air pollution.
The contribution of participatory decision making in the planning of ecosystem-based adaptation
Authors: Riera Spiegelhalder Mar , Campos Rodrigues Luís
Published: March 2024

Inland and coastal floods are becoming more frequent and severe, affecting natural and socioeconomic systems. Coastal urban areas, where population and economic activity are highly concentrated, appear as particularly vulnerable to these events. Local adaptation to climate change benefits from the integration of opinions from different stakeholders in the design and decision process, helping practitioners, planners, and policy makers to address climate change. This process can be operated under the umbrella of Living Labs, where innovative solutions to specific problems can be defined, designed and created through a social-iterative approach. Multicriteria analysis (MCA) is a suitable decision-making tool to develop within the context of Living Labs and climate change adaptation as it allows to capture perceptions from different actors about adaptation measures characterised though various criteria. This study presents the results of an MCA applied to the evaluation of Ecosystem-based Adaptation (EbA) to flooding in three Coastal City Living Labs of the Iberian Peninsula: An ex-ante analysis in Vilanova i la Geltrú (Spain) focused on potential measures to be implemented in an intermittent river-stream; Benidorm (Spain) followed an interim evaluation of planned EbA to address flooding in different city areas; and an ex-post analysis was performed in Oeiras (Metropolitan area of Lisbon; Portugal) to assess the perception of different stakeholders about the performance of already implemented measures along a river stream.
Data gap in air quality related health analysis and projections in data scarce regions of the world: Case study of West Africa 
Authors: Ewona igwe-Steve ,   Environmental Monitoring and Energy Research Group - Africa (EMERGAfri)
Published: March 2024

The health effect of air pollution is gaining global attention due, primarily, to elevated values of Particulate Matter (PM) with devastating consequences on health, agriculture, aviation and the climate system.  The increasing exposure to PM and its health effects have been backed up by scientific evidence around the world. A number of sources have been identified and are being tackled by various interventions. However, there are still subtle sources of air pollution, which are culturally related, that are neglected in most reports. This study takes a cursory look at some air pollution sources, common in the West African sub region, with possible serious health implications.  The dry season period has been identified as the most hazardous seasons in West Africa, in terms of air pollution, due to a combination of both natural and anthropogenic activities (such as: harmattan, bush burning, farmland preparation, ground sweeping, farm produce transportation, etc.) which are at their peak at this time of the year. These leave inhabitants exposed to PM values, far above WHO limits, for an average period of 5 months yearly. Harmattan winds, originating from the Sahara Desert, spray vast amount of fine particles between 0.5 and 10 microns into the region polluting the air and reducing visibility. Agricultural practices such as bush burning, farmland preparation and farm produce transportation on untarred roads generate PM in high concentration, which is directly inhaled by operators. In the same way, ground sweeping is done with the African broom and stirs dust directly to the face of the cleaner. Unfortunately, most of the cultural sources of pollution in West Africa and related diseases are poorly documented, and most air quality related analyses and reports on source apportionment neglect their contributions. Data used for most health related statistics and projections are from from satellite imageries, which in most cases, do not represent actual data on ground. Unfortunately, in-situ measuring stations are grossly inadequate, underscoring the need for increased on-ground based data collection and a comprehensive air pollution inventory in the region, to enhance data integrity and evidence-based research approach. 
Keywords: Harmattan, farm preparation, ground sweeping, source apportionment, air pollution, health effects,
Instantaneous Radiative Forcings of Greenhouse Gases  
Authors: van Wijngaarden William , Happer Will
Published: March 2024

The top of the atmsophere (TOA) instantaneous long wave radiative forcings resulting from increasing greenhouse gases such as CO2, CH4, N2O and various halogenated gases were found by solving the equation of transfer.  The observed altitude dependence of the greenhouse gas concentrations was used as well as the standard midlatitude temperature profile.  The calculations used the line intensities or absorption cross sections from the HITRAN database and also considered the effect of scattering by a cloud layer.  Various cloud properties were considered including altitude, optical depth and single scattering albedo for both isotropic and forward scattering.  The results show that a cloud layer reduces the TOA radiative forcing from its clear sky value.  The incremental forcing is even negative for an optically thick high altitude cloud.  This occurs because the temperature increases with altitude in the stratosphere.
Better weather forecasts = better human health? Yes, with TRIGGER(s)
Authors: Di Napoli Claudia , Wetterhall Fredrik
Published: March 2024

As the impacts of climate change on human health become increasingly evident, so does the need for a systemic and interdisciplinary understanding on the climate-health connection. Achieving such an understanding is key to the development of effective and rational adaptation plans, including those involving the creation of weather forecasts-driven systems that can increase the preparedness and response to health hazards.To address this shortcoming, the Horizon Europe project TRIGGER (SoluTions foR mItiGatinG climate-induced hEalth thReats) aims to generate and disseminate information about upcoming conditions detrimental to human health, such as heatwaves and cold spells, via an innovative prototype that integrates state-of-the-art climate and weather indicators with personal exposure monitoring data.We here present the TRIGGER prototype with a focus on the hydrometeorological prediction system that is tasked to forecasts health-impacting climate variables and indicators on temporal scales ranging from the short-range (hours) to sub-seasonal lead-time. Using a co-design approach involving medical doctors and epidemiologists, we describe how the system utilizes the ECMWF forecasts, provides probabilistic predictions for the near future, and enables the assessment of the associated uncertainty.
Real-time measurement of total and water-soluble organic carbon with developed online monitors 
Authors: Sioutas Constantinos , Aghaei Yashar , Aldekheel Mohammad , Tohidi Ramin , Badami Mehdi
Published: March 2024

In this study, two online monitoring systems were developed for measuring total organic carbon (TOC) and water-soluble organic carbon (WSOC) in fine and coarse airborne particles. The performance of these monitoring systems was assessed through field experiments to confirm their capability for real-time measurement. For collecting fine airborne particles, a versatile aerosol concentration enrichment system (VACES) coupled with an aerosol-into-liquid sampler (AILS) were utilized. On the other hand, the collection of coarse particles was conducted by two virtual impactors (VIs) in tandem with a modified BioSampler. These particle collection setups were connected to a Sievers M9 TOC analyzer to provide hourly readings of TOC and WSOC levels in water-based samples. Hourly average concentrations of TOC in fine and coarse particles were found to be 5.17 ± 2.41 µg/m³ and 0.92 ± 0.29 µg/m³, respectively. A parallel comparison was made with a Sunset Lab EC/OC analyzer, and a high degree of correlation in TOC readings was observed with R2 values of 0.89 and 0.85 for fine and coarse PM, respectively. Field tests were also performed to represent diurnal variations in WSOC levels bound to fine particles. The observed average WSOC concentrations for winter and summer were found to align closely with prior studies conducted in Los Angeles. In summary, validation was provided for the reliability of the novel developed monitors in the real-time measuring of TOC and WSOC, establishing their utility for future studies aimed at identifying pollution sources and their health impacts.
Freshwater fluxes drive decadal variability of the Amundsen Sea undercurrent and ice-shelf basal melt
Authors: Haigh Michael , Holland Paul
Published: March 2024

The ice sheets flowing into the Amundsen Sea, West Antarctica, are losing mass faster than most others about the continent due to rapid basal melting of their floating ice shelf extensions. A key oceanographic control of the rate of ice-shelf basal melting is a warm eastward undercurrent that flows along the continental shelf break and eventually towards the ice shelves. On monthly timescales surface winds drive fast barotropic variability in the undercurrent. On decadal timescales, however, undercurrent variability is not well understood. We present model results that show that on decadal timescales undercurrent variability opposes wind variability, with this being a consequence of sea-ice and ice-shelf freshwater flux variability. Specifically, periods of fast (more eastward) undercurrent are a result of enhanced brine rejection north of the continental shelf break, which enhances the cross-slope pressure gradient at depth and accelerates the undercurrent baroclinically. Opposite anomalies in the sea-ice freshwater flux decelerate the undercurrent. A positive feedback mechanism between the undercurrent and ice-shelf basal melt strengthens the undercurrent anomalies. Lastly, we show that variability in sea-ice freshwater fluxes, and by extension the Amundsen Sea undercurrent and ice-shelf basal melt, can be attributed to tropical Pacific variability impacting atmospheric conditions over the Amundsen Sea.
Study of major historical GLEs on the basis of historical records 
Authors: Mishev Alexander , Hayakawa Hisashi , Koldobskiy Sergey , Poluianov Stepan , Usoskin Ilya
Published: March 2024

A methodological study of relativistic solar energetic particles provides the necessary basis to reveal the nature of various processes, such as the production and acceleration of energetic particles at the Sun, their transport in the interplanetary medium, interactions of energetic particles with magnetic fields in the heliosphere, the induced corresponding terrestrial and space weather effects. Following solar eruptive processes, such as solar flares and/or coronal mass ejections solar ions are accelerated to a high-energy range. When the energy of the accelerated solar proton reaches the GeV/n range, it is enough high, so that solar ions generate an atmospheric cascade in the Earth’s atmosphere, whose secondary particles reach the ground, eventually registered by ground-based detectors, such as neutron monitors (NMs). This particular class of events is known as ground-level enhancements (GLEs). Over several decades, NMs provided the main records allowing analysis of GLEs, namely their spectral and anisotropy characteristics, a procedure requiring complicated modeling and several NM stations (records starting from GLE #5, 23-Feb-1956). However, the first four GLEs were recorded mostly by ionization chambers (ICs), devices with a weaker responses and greater energy threshold compared to NMs. Here, we analyzed several GLEs on the basis of historical records, where data of NMs and IC are both available. As a first step, we derived the GLE protons spectra employing a method verified by space-borne measurements. Secondly, employing a forward modeling, we rescaled the response of the available ICs, that is, we assessed the response function of selected ICs. Finally, employing a procedure similar to GLE analysis using NMs, but here using ICs records, we derived for the first time the spectra of e.g. GLE # 4. We compared the derived spectra with GLE #5 and discussed the obtained results.
Nonparametric estimation of age-depth relationships from sedimentological and stratigraphic information
Authors: Hohmann Niklas , De Vleeschouwer David , Batenburg Sietske , Jarochowska Emilia
Published: March 2024

Age-depth models are fundamental tools used in all disciplines that rely on geohistorical records. They assign ages to stratigraphic positions (e.g., in outcrops or drill cores), which is necessary to estimate rates of past environmental change and establish timing of events in the Earth’s history.Methods to estimate age-depth models commonly use simplified parametric assumptions on the uncertainties of ages of tie points, e.g., that they follow a normal distribution. The distribution of time between tie points is estimated using simplistic assumptions on the formation of the stratigraphic record, for example that sediment accumulation follows a Poisson process. As a result, these methods cannot incorporate evidence from complex empirical data or expert knowledge (e.g., from sedimentary structures such as erosional surfaces or from basin models) into their estimates, leaving important sources of information un- or underused.Here, we present two non-parametric methods to estimate age-depth relationships from complex sedimentological and stratigraphic data. The methods are implemented in the admtools package for R Software and allow the user to specify any error model and distribution of uncertainties. As use cases of the package, weconstruct age-depth models for Devonian strata in the La Thure section, Belgium, using sedimentation rates constrained by cyclostratigraphic methods.
use measurements of extra-terrestrial 3He from ODP site 690 (Maud Rise, Weddell Sea) to construct age-depth models for the Paleocene–Eocene thermal maximum.
examine how temporally variable 210Pb fluxes in lacustrine environments affect estimates of sedimentation rates and age-depth models.
These examples show how information from a variety of sedimentological and stratigraphic sources can be combined to estimate age-depth relationships that accurately reflect uncertainties of both available data and expert knowledge.
Atmospheric Tides Near the Equator on Mars
Authors: Leino Joonas , Harri Ari-Matti , Banfield Don , de la Torre Juárez Manuel , Paton Mark , Rodriguez-Manfredi Jose-Antonio , Lemmon Mark , Savijärvi Hannu
Published: March 2024

Diurnal solar radiation forces global oscillations in pressure, temperature, and wind fields. They are called atmospheric or thermal tides and are additionally modified by topography, surface properties, and atmospheric absorber consentration. They propagate around the planet in periods that are integer fractions of a solar day and are only relevant in the upper atmosphere on Earth, but they represent a very large part of the atmospheric circulation on Mars. First two harmonic components (diurnal and semi-diurnal), with periods of 24 and 12 hr at the locations of InSight and Mars Science Laboratory (MSL) are represented here with the comparison to Mars Climate Database (MCD) predictions.Both of these landers are located in the tropics, InSight on Elysium Planitia (4.5°N, 135.6°E) and MSL within the Gale Crater (4.6°S, 137.4°E). In this study, we utilized observations of the time period from Martian year (MY) 34 solar longitude (Ls) 296° to MY 36 Ls 53°. Diurnal amplitude was larger than semi-diurnal amplitude on both platforms and similar sensitivity to atmospheric dust content was found. However, the amplitude of the semi-diurnal component was smoother than the diurnal amplitude due to its sensitivity to global atmospheric dust content. One clear difference between the platforms was the average amplitude of the diurnal tide, which was 17 Pa for InSight and 33 Pa for MSL. Lateral hydrostatic adjustment flow, generated by the topography causes this difference since it increases the diurnal range of pressure within the Gale. Diurnal tide phase at the InSight was lower than that at the MSL, with averages of 03:39 and 04:25 LTST. In addition, MSL detected roughly contant diurnal tide phase, but InSight observed much more variation. Semi-diurnal phase pattern was very similar on both platforms.Diurnal tide amplitude predicted by the MCD mimicked the observations quite well at both locations, except during MY 35 Ls 0°–180°. During that time, MCD amplitudes were lower than observed. This is very likely explained by the atmospheric dust conditions, due to the sensitivity of the diurnal tide to the local atmospheric dust loading. MCD dust optical depth was in good agreement with MSL observed optical depth during MY 35 Ls 180°–360°, but was lower than observed during MY 35 Ls 0°–180°. MCD semi-diurnal amplitudes mimicked the observations well throughout MY 35 due to its sensitivity to global atmospheric dust loading.
The Key Role of the Vertical Structure of the Stratospheric Quasi-Biennial Oscillation in the Variations of Asian Precipitation in Summer
Authors: Luo Fuhai , Luo Jiali , Xie Fei , Tian Wenshou , Hu Yihang , Yuan Leiye , Zhang Ruhua , Wang Tao
Published: March 2024

Based on observations and numerical simulations, this study explores the responses of Asian precipitations in summer to the vertical structure of Stratospheric Quasi-Biennial Oscillation (QBO), and the relevant mechanisms. Compared to the QBO phase defined by a particular level traditionally, considering QBO's vertical structure leads to more significant precipitation responses. When the tropical zonal winds exhibit easterlies (westerlies) at 70 hPa and westerlies (easterlies) at both 30 hPa and 50 hPa, there are downwellings (upwellings) over tropics and upwellings (downwellings) over mid-latitudes in the upper troposphere and lower stratosphere (UTLS). The meridional movement of the subtropical westerly jet (SWJ) is related to this secondary circulation, accompanied by anomalies of the South Asian High (SAH). These circulation anomalies lead to anomalous lower tropospheric circulations, causing abnormal vertical velocities and moisture transports, resulting in increased precipitation over South Asia and decreased precipitation in the Yangtze River basin.
Basal debris at an Antarctic ice rise revealed by seismic amplitude-vs-angle analysis. 
Authors: Agnew Ronan , Brisbourne Alex , Booth Adam , Clark Roger
Published: March 2024

Reconstructing past ice sheets is important for understanding the response of modern ice sheets to changes in climate. The evolution of the Weddell Sea Sector’s grounding line since the last glacial maximum (LGM) to its present position remains ambiguous; previous authors have proposed hypotheses both of monotonic grounding line retreat and of rapid grounding line retreat followed by readvance. However, distinguishing these scenarios with current observations remains difficult. To explore these scenarios, we report seismic measurements of basal properties at KIR, an ice rise in the Weddell Sea Sector, West Antarctica. A three-component seismic survey enabled detection of the compressional (P) wave reflection and the converted (PS) wave reflection (an incident P wave converted to a shear wave at the base-ice reflector) from the base of KIR. Amplitude-vs-angle (AVA) analysis aims to constrain the physical properties (namely density, seismic velocity, by measuring the variation of reflectivity with incidence angle at the reflector. By jointly inverting the AVA responses of the PP wave reflection and the PS reflection, we increase the confidence in the interpretation of the base-ice properties. Analysis of PP and PS AVA responses at KIR indicates that the reflection arises from a material with a P wave velocity of 4.03 ± 0.05 km/s, an S wave velocity of 2.16 ± 0.06 km/s and a density of 1.44 ± 0.06 g/cm3; these properties are consistent with a reflection from a layer of entrained basal debris, with 20-30% debris by volume. The observed properties are not indicative of interference at a thin layer, as observed beneath glaciers elsewhere. The absence of deeper subglacial reflections indicates a poorly-defined boundary between this basal debris layer and the underlying subglacial material, which we therefore propose consists of frozen sediments . If this interpretation is correct, the presence of a debris layer overlying basal frozen sediment indicates a potential retreat/readvance scenario for KIR. A possible scenario is a previous episode of flow during which KIR may have been weakly grounded as an ice rumple, followed by grounding on the lee side of the bathymetric high and subsequent freezing of subglacial sediments. However, the origin of such a homogeneous and debris-rich layer remains unclear. The indication of a reflection from a basal debris layer raises questions about whether conventionally interpreted basal reflections can truly be considered as such, and whether these interpretations may mask the true nature of the underlying subglacial material. This ambiguity may be most effectively reconciled by borehole sampling.
Scenario-based Assessment of Land Use Change on Air Quality
Authors: Sarkar Tanbir , Gautam Anita , Behera Mukunda D. , Aithal Bharath H.
Published: March 2024

In recent decades, growing urbanization and rapid land use changes have been important components of current development, affecting environmental dynamics, particularly air quality. Over 80% of city people may be exposed to levels of pollution that exceed WHO standards (WHO 2016). Previous research focused solely on the relationship between built-up space and particulate matter (PM), with no concern for future scenarios. This study explores the potential impact of land use change on air quality using a detailed scenario-based technique. The air pollutant data for 2022 was principally gathered from five distinct land uses, whereas previous years (2010 to 2021) were received from the Central Pollution Control Board. In a supervised classification technique, a Maximum Likelihood Classifier is utilized to analyze the LULC of 2010, 2016, and 2022 in Kharagpur, a rising industrial town and the fourth-largest city in West Bengal. The analysis shows a strong 20.62 percent rise in urban areas, particularly in the eastern region, from 2010 to 2022, comprising residential, commercial, and industrial zones. Between 2010 and 2022, there is an 11.23 percent loss in vegetative areas, a 9.29 percent decrease in agricultural land, and a 0.10 percent decrease in aquatic bodies. Further spatiotemporal analysis reveals that areas with low urban density had the lowest amounts of air pollution, with an overall Air Quality Index (AQI) in the "excellent" range (0-50). Industrial land use contributes 74.37 percent to air pollution, followed by densely populated urban regions, which have a 47.62 percent higher AQI than low-density zones. Furthermore, the vehicular corridor has a 33.49 percent higher AQI than low-density places. According to the data, the most significant pollutants leading to AQI variance are PM2.5 and PM10. A correlation study emphasizes the effect of land use changes on air quality since PM10 was followed by overall AQI is positively related to built-up areas and negatively related to vegetation and water bodies. It suggests that fast urbanization may damage air quality, but vegetation and waterbodies might improve air quality and lower AQI. Polluted air has a negative impact on human health, agricultural production, and numerous ecosystems, putting future urban growth at risk. It is therefore critical to assess future land use changes in order to predict future air quality settings and take preventive efforts to mitigate air pollution. To compare future air quality settings to a baseline, two scenarios for LULC prediction are examined: business as usual (BUA) and sustainable development (SD). These scenarios can help determine future urban development paths, as well as land use planning and policy-level action to improve air quality.Keywords: Land Use change, Air quality, Time series forecasting, CA-ANN, Scenario-based Analysis, Kharagpur.
A novel composite Index for early-season maize mapping
Authors: Gao Yuan , Pan Yaozhong , Ren Shoujia , Zhao Chuanwu
Published: March 2024

Maize cultivation significantly contributes to global food security and sustains human livelihoods. Efficient early-season maize mapping is pivotal for forecasting production and informed pre-harvest decisions. Existing approaches rely on prolonged phenological data or available crop labels, limiting their applicability in areas lacking comprehensive data. Thus, an automated, dynamic, and accurate maize identification method for the early growing season is crucial. This study explores spectral bands to distinguish maize early in terms of water content and chlorophyll levels. A novel composite index for dynamic maize identification independent of labels was proposed. Utilizing this index with a multi-temporal Gaussian Mixture Model facilitated early-season maize mapping and identification. Assessments across diverse global regions revealed the method's robustness, consistently achieving 90% accuracy and F1-score. NDCI outperformed other indices, enhancing F1-score by up to 30%. NDCI-mGMM accurately generated maize maps two months pre-harvest, promising an F1 score of at least 77%. Operating autonomously from labels, this framework offers swift and precise maize identification in data-deficient regions, revolutionizing global food security and trade forecasts.
Distributive Justice in Multi-Objective Optimization: A Priori vs. A Posteriori Approaches in Eastern Nile Basin Management  
Authors: Znabei Meron , Zatarain Salazar Jazmin , Kwakkel Jan , Doorn Neelke
Published: March 2024

Addressing global water scarcity requires effective, sustainable water resource management. However, water resources management problems are complex challenges with multiple, often contradicting, objectives. Moreover, increasingly, questions are raised regarding the fair allocation of scarce water resources. In this study, we use multi-objective optimization as an approach to explore the trade-offs between these conflicting objectives. Questions pertaining to fair allocation are commonly integrated a posteriori. In contrast, this study explores their a priori incorporation and the impact of doing so on the trade-offs identified through multi-objective optimization. We investigate utilitarianism, egalitarianism, and prioritarianism, representing diverse theories of distributive justice. These theories guide the translation of justice principles into mathematical models, offering insights into how societal values influence water distribution. Our research centers on the management of the heavily disputed shared water resources within the Eastern Nile River Basin. We compare a priori and a posteriori integration of distributive justice principles to find Pareto-optimal trade-offs across irrigation, hydropower, and urban supply objectives for Sudan, Egypt, and Ethiopia. Our findings demonstrate that the a priori integration produces trade-offs that differ significantly from those obtained through analyses that omit distributive justice principles during optimization and only incorporate them post-optimization for filtering. Utilitarian integration enhances overall system performance, egalitarian integration diversifies solutions, and prioritarian integration produces sharper trade-offs, highlighting the challenges in reconciling distributive justice principles. Our findings contribute to the broader discourse on ethics in many-objective optimization, offering valuable insights for policymakers and water resource managers, especially in contexts where sustainability and fair distribution of water resources are essential. 
Retrieving stress and elastic properties distributions from stress orientation and satellite data using physics-informed machine learning
Authors: Poulet Thomas , Behnoudfar Pouria
Published: March 2024

Traditional geomechanical modelling involves a lot of a priori knowledge regarding, among others, the distribution of material properties and boundary conditions to apply to a model. Setting those parameters is usually time-consuming, starting with extensive literature reviews to get initial estimates, which are then refined by trial and error by calibrating the numerical simulations against observations. In particular, the boundary conditions typically remain poorly constrained since precise data is rarely available.In this contribution, we present a physics-based machine learning approach to infer the current displacements and full stress tensor distribution of an effective 2D linear elastic model, based on stress orientation and Global Navigation Satellite System (GNSS) data. This allows for automatic retrieval of a reasonable approximation of the model's elastic material properties, consistent displacement, and stress values over the whole physical domain, including at the boundaries, which could be used for instance in following forward simulations.We show an application to the Australian continent, for which a rich dataset of stress orientation is available from the World Stress Map project and the GNSS measurements are particularly steady. This allows us to compare various options to account for stress orientation and displacement information as input data. Interestingly, we recover the smoothest stress field compatible with the (very accurate) GNSS observations and consequently identify areas where the resulting stress orientation differs from current estimates.