bluuebunny/crossref_metadata_2025 huggingface dataset:
Wildfire Art: Lessons in Science and Art
Authors: Van Rees Ken
Published: March 2024

Over 18.5M ha of forests have burnt in Canada in 2023 far surpassing the previous record of 7.6 M ha set in 1989. How do we engage the public with the enormity of this natural disturbance on our landscapes and it possible causes? As a scientist and an artist, I was in a unique position to explore the possibilities of creating new ways of doing research in these landscapes. Almost 15 years ago a wildfire burnt my research plot and destroyed my monitoring equipment in northern Canada. As I examined the damaged equipment, charcoal imprints were made on my clothing which led to exploring how to capture charcoal markings in burnt forests. That fire changed my perceptions of research and art and began the journey of how I might use science and art to address environmental issues. On a sabbatical to Berlin, I was challenged to think about how science might inform art and how my art might inform my science.  My charcoal artwork the past 14 years has been a unique opportunity to look at wildfires and understanding the movement of charcoal in these burnt forests and how my artwork has revealed some of these transfers. This presentation will discuss how my charcoal artworks in burnt forests has driven my ideas about science and art with regards to natural disturbances and the communication of these disturbance events to the public.
Synthetic Aperture Radar Altimetry Processing on Demand at ESA’s Altimetry Virtual Lab
Authors: Benveniste Jérôme , Restano Marco , Dinardo Salvatore , Buchhaupt Christopher , Scagliola Michele , Passaro Marcello , Fenoglio-Marc Luciana , Ambrózio Américo , Orrù Carla
Published: March 2024

This presentation updates on the ESA Altimetry Virtual Lab for the exploitation of CryoSat-2 (CS-2), Sentinel-3 (S-3) and Sentinel-6 Michael Freilich (S-6MF) data from L1A (FBR) data products up to SAR/SARin L2 geophysical data products. The following on-line & on-demand state-of-the-art research  algorithm services compose the portfolio:The ESA-ESRIN SARvatore service for CS-2 and S-3 services, which allow users to customise the processing at L1b & L2 (a list of configurable options for, e.g., SAMOSA+/++ and ALES+ SAR retrackers, not yet available in the ESA Ground Segment).
The ESA SAMPY (Cryo-TEMPO project) for CryoSat-2, which appends the SAMOSA+ retracker output to official CryoSat-2 Level-2 GOP products.
The TUDaBo SAR-RDSAR (TU Darmstadt–U Bonn SAR-Reduced SAR) for CS-2 and S-3, which allows users to generate reduced SAR, unfocused SAR & LRMC data, with configurable L1b & L2 processing options and retrackers (BMLE3, SINC2, TALES, SINCS, SINCS OV).
The TU München ALES+ SAR for CS-2 and S-3, which allows users to process official L1b data and produces L2 products by applying the empirical ALES+ SAR subwaveform retracker, including a dedicated Sea State Bias solution.
The Aresys Fully-Focused SAR for CS-2 & S-3, to produce L1b products with configurable options and appending the ALES+ FFSAR output.
These services will be extended with the following new services:Appending the SAMOSA+ retracker output in all services.
The Aresys FF-SAR service for S-6MF
The CLS SMAP S-3 FF-SAR processor extended to process S-6MF
The UBonn FF-SAR Omega-Kappa processor for S-3 and S-6MF
An upgrade of the TUDaBo SAR-RDSAR extended to S-6MF with new ocean and coastal retrackers.
The ESA-ESTEC/isardSAT L1 S-6MF Ground Prototype Processor.
SAR services updated to process S-6MF
Output products are generated in netCDF, therefore compatible with the multi-mission “Broadview Radar Altimetry Toolbox” (BRAT, http://www.altimetry.info).The ESA Altimetry Virtual Lab, a community space for simplified services and knowledge-sharing, is hosted on the EarthConsole® (https://earthconsole.eu), supported by the ESA Network of Resources. This service has more than 120 users and sponsored so far more than 500 CPU years, leading to more than 30 publications and 3 PhD theses.Brochure at https://earthconsole.eu/knowledge-base/. Info at altimetry.info@esa.int.
Constitutive behavior of rocks during the seismic cycle in non-isothermal, non-isobaric conditions
Authors: Barbot Sylvain
Published: March 2024

Establishing a constitutive law for fault friction is a crucial objective of earthquake science. However, the complex frictional behavior of natural and synthetic gouges in laboratory experiments eludes explanations. Here, we present a constitutive framework that elucidates the slip-rate, state, temperature, and normal stress dependence of fault friction under the relevant sliding velocities and temperatures of the brittle lithosphere during seismic cycles. The competition between healing mechanisms explains the low-temperature stability transition from steady-state velocity-strengthening to velocity-weakening as a function of slip-rate and temperature. In addition, capturing the transition from cataclastic flow to semi-brittle creep accounts for the stabilization of fault slip at elevated temperatures. The brittle behavior is controlled by the real area of contact, which is a nonlinear function of normal stress, leading to an instantaneous decrease of the effective friction coefficient upon positive normal stress steps. The rate of healing also depends on normal stress, associated with an evolutionary response. If these two effects do not compensate exactly, steady-state friction follows a nonlinear dependence on normal stress. We calibrate the model using extensive laboratory data covering various relevant tectonic settings. The constitutive model consistently explains the evolving frictional response of fault gouge from room temperature to 600º for sliding velocities ranging from nanometers to millimeters per second, and normal stress from atmospheric pressure to gigapascals. The frictional response of faults can be uniquely determined by the in situ lithology and the prevailing hydrothermal conditions.
Phenology and knowledge mobilization about the importance of trees in urban environments in southern Quebec, Canada
Authors: Levac Elisabeth , Courtemanche Bruno
Published: March 2024

A phenology project was launched in 2020 in the Eastern Townships region of southern Quebec, Canada, with the help from students from Bishop’s University. Initially, one of the main goals was to boost local phenology observations and gather data that will become useful in the future to document the impacts of climate change. We also wanted to pair the pollen monitoring programme that exists in Sherbrooke since 2006 with directs phenological observations of the local vegetation. The other goal of TreeTraque is to increase people's awareness of the impacts of climate change on vegetation. Riding on the momentum generated by the recent adoption of the politique de l’arbre (tree- or greening policy) by the city of Sherbrooke and by the push from numerous conservation organizations within the region, we are now adding a knowledge mobilization component to the project. We wish to reach the genera public more broadly to educate them about the importance of trees in the urban environment: they combat the urban heat island effect, capture atmospheric pollution, and enhance the esthetics of a neighbourhood. A few greening programs are already in place in Sherbrooke, however, they only aim at planting trees on institutional, industrial and commercial lots. It appears important to raise awareness among the general population, especially homeowners. Indeed, in some neighbourhoods, we see that numerous owners choose not to have trees on their property or prefer shrubs or plants that do not provide any shade on buildings, streets or driveways. Our long-term objective is to create more shade to help combat the urban heat island effects and reduce the impacts of future heat waves.  
Urban Residents’ Justice Preferences in the Design of Climate Adaptation Flood Policy
Authors: Tier Melissa , Weber Elke , Oppenheimer Michael
Published: March 2024

There is an increasing need for ex-ante climate adaptation policy planning and design. Moreover, meeting robust standards to minimize harm and environmental inequities will require innovative practices and foresight, but little is currently known regarding how such standards influence residents’ preferences for or against climate policies. One set of climate adaptation strategies ripe for such consideration is urban risk management for worsening flooding. These strategies are often complex and controversial (e.g., choices between protection, retreat, and relocation), and can vary widely in structure with regard to key justice components (e.g., types of distributive, procedural, and corrective justice). This presentation will share results from a large-scale, international survey that examined a comprehensive set of justice values underlying residents’ urban flood policy preferences. The online survey was translated and administered in 5 cities globally (n=650 residents per city): Buenos Aires (Spanish), Johannesburg (Zulu & English), London (English), New York City (English, Spanish, & Korean), and Seoul (Korean). The survey explores which urban climate adaptation flood policies are generally preferred by residents, whether certain categories of policies are preferred over others, and whether certain characteristics of residents best predict their preferences. More specifically, analysis of survey data considers which variables are best predictors of differences in policy preferences: a) self-perceived vulnerability to flood risk; b) city of residence; c) political, economic, and psychological worldviews; or d) other common demographics. Preliminary analysis of survey results suggests that residents with higher self-perceived vulnerability to flood risk also have an increased likelihood of preferring more expansive adaptation strategies (i.e., not just homeowner-focused policies, not just protection strategies, and more reparative actions). This survey was designed to integrate contemporary topics in environmental justice, climate adaptation, and urban planning. The hypothesis was that people who self-identify as more vulnerable to flood risk prefer policies that focus more on other vulnerable people – in other words, an empathy effect caused by higher salience of vulnerability. Moreover, this effect was expected to be stronger than that of city of residence, worldviews (e.g., political identities), and other demographic characteristics. The presentation will both review detailed statistical analysis of the survey data, as well as discuss recommendations for how to best frame risk management policies in order to increase support for policies aimed at minimizing environmental inequities. This dissertation thesis project has been supported by the Princeton School of Public & International Affairs and the 2023 Young Scientists Summer Program at the International Institute of Applied Systems Analysis.
LEO Satellites as Sensors for Thermospheric Mass Density and Drag Research  
Authors: Thayer Jeffrey , Pilinski Marcin , Sutton Eric , Waldron Zach , Ray Vishal
Published: March 2024

The charge to the space science community is to improve specification and forecast of the low Earth orbit (LEO) space environment to provide reliable collision avoidance and risk assessment analyses for space traffic management and reduce the number of false conjunction warnings. The challenge is that the prediction of LEO object trajectories is severely limited. This is due primarily to poorly captured variability in neutral density estimates during space weather events, resulting in large and variable position errors of all resident space objects across LEO. To improve operations in LEO, the specification and forecast of the thermosphere neutral mass density must improve.Most recently launched LEO satellites are equipped with global navigation satellite system (GNSS) devices, making them excellent sources of continuous orbit ephemeris to enable precision orbit determination (POD). Many are also equipped with attitude and vehicle knowledge to allow for the construction of an accurate force model. Combining these “data of opportunity” from LEO satellites with POD processing tools offers the possibility of extracting thermospheric mass density information regularly and globally from the multitude of GNSS-equipped LEO satellites in operation today.This talk explores this possible trove of LEO space environment data by investigating methods and providing specificity to the level of data information required to provide useful mass density outcomes. The ICESAT-2 spacecraft is used as a test vehicle for this type of analysis. The NASA GSFC GEODYN POD software is employed to produce precise science orbits for the ICESAT-2 spacecraft. These precise science orbits are then used to extract mass density estimates along specified orbital arcs. Simulation is also employed to address the potential errors of system requirements and how they can influence the thermospheric mass density estimate from LEO spacecraft. The future GDC mission will also be highlighted as a much-needed LEO space environment resource for direct multi-point measurements of the thermospheric gas and ionospheric plasma. These direct neutral measurements will enable a careful validation of POD-extracted densities. By fully characterizing all free-stream parameters, GDC is also a well-equipped constellation for studying the gas-surface interactions critical for drag research.
First TanSat CO2 retrieval over land and ocean using both nadir and glint spectroscopy
Authors: Zhang Chengxin , Hong Xinhua , Liu Cheng
Published: March 2024

The world is facing a serious warming crisis, highlighting the need for monitoring greenhouse gases such as carbon dioxide (CO2). In 2016, China launched its first satellite mission for measuring atmospheric CO2, i.e., TanSat. Previous TanSat retrievals of the column-averaged dry air mole fraction of CO2 (XCO2) have a moderate precision of 1.47–2.45 ppm, with only limited spatial coverage over the land surface by using TanSat nadir-mode (ND) spectroscopy. These existing gaps are affected by the poor signal-to-noise ratio of glint mode (GL) or over the oceanic surface. However, CO2 measurements over the ocean, a major source of global carbon sinks, are often lacking and subject to significant uncertainties but are nevertheless quite important. To increase the spatial coverage and retrieval accuracy and precision of TanSat CO2, we further improve XCO2 retrieval by introducing spectral recalibration, spectral window optimization, and explicit radiative transfer simulation. Thus, universal CO2 retrieval with high precision over land and ocean is realized by using both ND and GL spectra. Ground-based comparisons using the total carbon column observing network (TCCON) indicate that the standard deviations of the bias-corrected XCO2 retrievals from the ND and GL modes were 1.28 and 1.19 ppm, respectively. Consistent spatial and temporal distributions of satellite XCO2 retrievals can also be found among TanSat, the Greenhouse gases Observing SATellite (GOSAT), and the Orbiting Carbon Observatory-2 (OCO-2) satellites. The updated TanSat XCO2 retrievals have ~3.5 times the seasonal spatial coverage of GOSAT, while the highest difference between TanSat and OCO-2 is only +0.63 ppm. In addition, TanSat XCO2 retrievals over the ocean successfully captured enhanced CO2 plumes from the neighboring Yasur volcano, with an estimated emission flux of 32.1 kilotons per day. These results indicate that the improved TanSat XCO2 retrieval is useful for understanding and quantifying global land and ocean carbon emissions.
Evaluation of a UAV-Based Methodology for Measuring Flare Combustion Efficiency
Authors: Festa-Bianchet Simon , Mohammadi Milad , Tanner Alexis , Kopp Greg , Johnson Matthew
Published: March 2024

This work will present a quantitative evaluation of the potential for measuring gas flare combustion efficiency using an aspirating sensor platform mounted under an uncrewed aerial vehicle (UAV).  The UAV sensor package contains lightweight commercial gas analyzers capable of precise measurements of atmospheric methane (CH4), ethane (C2H6), carbon dioxide (CO2), and carbon monoxide (CO).  By sampling the flare’s plume of combustion products with the help of a UAV, flare efficiency measurements can be safely and remotely completed without affecting the flare’s operation.  The relative mole fraction of the measured major carbon containing species can be used to close a carbon mass balance, which permits calculation of a local carbon conversion efficiency of the flare.  However, because the composition of the flare plume can be inhomogeneous as well as turbulent, it is not straightforward to determine whether the measured incomplete combustion products are representative of total inefficiencies.  Further uncertainty arises if the flared gas contains additional hydrocarbon species (e.g., C3+ hydrocarbons) that may not be directly measurable by the UAV platform.  To address these challenges, controlled experiments were completed on large scale (100-mm diameter) flares burning within Western University’s Boundary Layer Wind Tunnel.  With the wind tunnel running in an open circuit configuration, the UAV/sensor package was suspended within the wind tunnel test section downstream of the flare where it measured combustion efficiency while being moved in and out of the combustion plume.  Results were compared with known combustion efficiencies for identical operating conditions obtained following the established method of Burtt et al. (J. Energy Inst. 2022).  Further, combustion efficiency measurements from operating flares will be made using the developed sensor to validate the proposed measurement approach.  Ultimately, this tool could close a known gap in our ability to quantify carbon conversion efficiency and methane slip from flares under field conditions as required under emerging measurement, reporting, and verification (MRV) programs.  
Wetland trees are a potential methane sink during dry soil conditions
Authors: Gomez Carla , Pangala Sunitha , Gowing David , Olsson-Francis Karen , Page Susan , Gauci Vincent
Published: March 2024

The contribution of trees to the wetland methane (CH4) budget remains highly uncertain. The water table level is an essential driver for stem CH4 emissions, which vary across seasons and soil hydrological conditions. Exceptionally dry conditions are increasingly affecting forests because of climate change, and wetland trees can potentially switch from CH4 sources to sinks. CH4 production and oxidation potentially occur in the oxic/anoxic microsites within wetland tree stems, as in soil, balancing the net stem CH4 emissions to the atmosphere. Yet, the microbial ecology behind these processes is still vastly unexplored, and understanding the role of microbial ecology is essential to predict stem CH4 emission patterns.Our study focused on characterising stem CH4 fluxes using semi-rigid static chambers and assessing CH4 oxidation and production activities through gas-enriched incubations in two forested wetland ecosystems: a temperate wetland in Flitwick Moor (UK) and tropical peat swamp forests in the Sebangau Forest (Kalimantan, Indonesia), both experiencing lower water table levels than previous years during the same period. Targeted tree species were measured at multiple height intervals and were Alnus glutinosa and Betula pubescens in Flitwick Moor and Shorea balangeran and Xylopia fusca in the Sebangau Forest, the same tree species that were investigated in earlier studies at these sites. DNA analysis from bark, wood, and soil involved two-step PCR and sequencing targeting the 16S rRNA gene, complemented by whole shotgun metagenomics (WGS) to explore the microbial composition and CH4-cycling microorganisms.Results from Flitwick Moor and the Sebangau Forest showed significantly reduced stem CH4 emissions (
Mitigating Methane Emissions: A Comprehensive Measurement Study of Canadian Landfills
Authors: Khaleghi Afshan , Bourlon Evelise , Omidi Athar , Stuart Jordan , Martino Rebecca , Ghasemi Donya , Fougere Chelsea , Darlington Andrea , Ars Sebastien , Gillespie Lawson , Goeckede Mathias , Risk David
Published: March 2024

Canada’s waste sector contributes 23% toward national methane emission totals. Recently Canada committed to a 50% reduction in waste sector methane emissions by 2030 from 2020 levels, as part of its Global Methane Pledge action plan. Achieving this ambitious goal will certainty requires that regulators to be armed with an accurate and measurement-informed understanding of landfill methane emissions. In 2022 we carried out a snapshot methane emissions quantification campaign targeting 125 landfills across Canada, followed in 2023 by more detailed source-level measurements across seasons at selected landfills in various climate zones. Snapshot measurements were carried out by vehicle-based surveying coupled with Gaussian and Lagrangian flux inversion, and aircraft mass balance measurements. Repeating source-based measurements were conducted in 2023 across seasons at 12 landfills for 3 climatic regions using vehicle-based surveys, stationary tripod deployments, and drone measurements of plumes, from on-site and off-site locations. Source-specific flux rates were generated based on triangulation, Lagrangian backtrajectory analysis, and a Gaussian dispersion model, and were assessed for magnitude and temporal variability.  In snapshot measurement campaigns across the country, we saw generally good agreement between aircraft mass balance and truck measurements, with a moderate but consistent low bias in the truck emission rate estimates. Lagrangian methods to derive flux rate were comparable as long as input data was limited to exclude highly enriched onsite samples. Throughout a varied population of landfills across Canada, we found that emission rate estimates from measurement campaigns were generally in-line with operator-submitted values to the Canadian Greenhouse Gas Reporting Program, whereas a First Order Decay model used by the federal government for planning purposes tended to over-estimate landfill emissions. Climate zone was a clear predictor of methane generated per waste in place. In more detailed source studies, we found that numerous features on landfill operations could emit methane, most expected, but some unexpected. Management practice was a strong predictor of whether source types emitted significantly, or not. Meteorology and seasonal changes in climate were also strong predictor of emissions over time. These large-scale studies provide a wealth of data upon which Canada can base regulatory development and will be beneficial to countries with similar waste sector patterns and climates.
Snow-depth Spatial Distribution Analysis Technology linked to Ground Observation Network
Authors: Kang Narae , Yoon Jungsoo , Hwang Seokhwan
Published: March 2024

In this study, we attempted to classify snowfall patterns using multiple dual-polarization radars and quantitatively review the amount of snowfall observed from radar using a ground observation network (snow depth). In order to more quantitatively compare the difference between radar reflectivity and precipitation (snow) intensity compared to ground observed snow depth, comparison was made on an hourly basis, taking into account the Korea Meteorological Administration's snow observation data provision period (1 hour). Radar observation data were compared with precipitation intensity based on cumulative reflectivity, differential reflectivity, and specific differential phase difference. Compared to radar reflectivity, there were various delays ranging from 2 to 7 hours from the time the precipitation intensity accumulated with the snow depth. In addition, the difference between the time of increase in snow cover is judged to be an error generated by the wind, and it is necessary to expand the range of radar pixels as well as the blinding factor to take into account the influence of wind. AcknowledgmentsThis research was supported by a grant(2022-MOIS61-003(RS-2022-ND634022)) of Development Risk Prediction Technology of Storm and Flood for Climate Change based on Artificial Intelligence funded by Ministry of Interior and Safety(MOIS, Korea).
Evaluation of compound precipitation and temperature extremes in a changing climate 
Authors: Dhakal Nirajan
Published: March 2024

Past studies on weather and climate extremes have focused on individual extremes. These studies cannot effectively track/model compound extreme events. The major objective of this study is to evaluate the changing risk of compound precipitation and temperature extreme events based on historical observed period (1964–2014) and the future period (2045-2054 and 2085-2094). We explored four different compound extreme event impacts of temperature and precipitation (dry-warm, dry-cold, wet-cold, and wet-warm) at the United States Department of Energy Office of Environmental Management (DOE-EM) sites. 25% and 75% quantile thresholds were used to define extreme climate conditions. The empirical approach for the analysis of compound extremes was conducted by counting the number of concurrent occurrences of multiple extremes during the same month (year). The empirical probability density function of compound events was constructed using nonparametric kernel density estimators to compare the seasonal distribution of four different compound event modes. Our results show slightly increasing trends in both Wet-Cold Mode and Wet-Warm Mode, and slightly decreasing trends in Dry-Cold Mode. Results from our study provide better understanding of the impact of climate extremes on mission-critical assets at EM cleanup sites.
Nature of asperities and barriers along the Chilean megathrust unveiled by an integrated analysis of seismicity, gravity, geodetic locking and wedge geometry
Authors: Tassara Andres , Sippl Christian , Riedel Martin , Castro Catalina , Carcamo Favio
Published: March 2024

Asperities inside the seismogenic zone of subduction megathrust are regions where specific frictional properties allow a stick-slip behavior characterized by the accumulation of slip deficit over decades to centuries and its sudden release during earthquakes. Despite its major role on the occurrence of the most devastating earthquakes and tsunamis on the planet, the physical nature of asperities and their limiting barriers is still unclear. This is partially due to an, often, ambiguous interpretation of individual geophysical proxies that are theoretically connected with the frictional structure of the megathrust at quite different time scales, ranging from 100-102 yrs (seismicity patterns, geodetic locking, Vp/Vs and MT anomalies) to 105-107 yrs (coastal geomorphology, forearc wedge geometry and associated basal friction, magnetic and gravity anomalies). If transient phenomena, like slow slip events (SSEs) or stress shadows created by previous earthquakes, do not dominate the seismogenic behavior of the megathrust, then short- and long-term frictional proxies should coincidently illuminate the location of asperities and barriers. Moreover, this would imply that the nature of this features must be connected to the geology structure of both converging plates, with strong implications to seismic hazard assessment. A number of previous studies have explored a combination of several geophysical proxies for megathrust frictional structure, most of them along the Chilean margin. Here we expand over the work of Molina et al. (2021) and Sippl et al. (2021) by performing an integrated analysis of gravity anomalies, friction from critical wedge theory, geodetic locking and seismicity patterns for the entire 4000-km long Chilean megathrust. Particularly, we use available (micro)seismicity catalogues to compute maps of the b-value of the frequency-magnitude relationship. This parameter contributes with an independent short-term proxy for the stress state of the megathrust and we treat it as an additional continuous field into a principal component analysis (PCA) similar to Molina et al. (2021) that aims to quantify the main spatial correlation between the proxies. We will also test other techniques to measure the degree of spatial correlation, like AI-based pattern recognition methods. This integrated analysis will also consider rupture length of historical earthquakes over the last 500 yrs and slip distribution of instrumental earthquakes and SSEs. This will allow us to test contrasting hypothesis about the nature of seismic asperities and barriers along the Chilean megathrust and elsewhere.
Construction and Test of WRF Model in Chinese Mainland
Authors: Yang Mingxiang
Published: March 2024

Based on WRF model, this paper constructs a mesoscale numerical weather forecast model covering Chinese Mainland, with a spatial resolution of 5km. Driven by ERA5 reanalysis data, long-term simulation experiments are carried out. We selected observation data from the National Meteorological Station of China to test and analyze the core forecast elements such as precipitation, temperature, and wind speed of the WRF model, and further verified the simulation ability of the model for typhoons, extreme precipitation, sustained drought, and total water resources in different water resource zones, obtaining relatively objective evaluation results. On this basis, based on WRF-Hydro, a regional distributed hydrological model in Chinese Mainland is constructed. The WRF-Hydro model is driven by the long-term simulation results output from the WRF model, and the runoff simulation data corresponding to major rivers in China are obtained. By comparing with the measured data, the validity of the WRF model built in this paper in hydrological simulation is verified, which provides a reference for the next step of operational application and improvement of the model.
Constraining LLSVPs initial conditions and heating scenarios from simulations of mantle convection with heterogeneous thermal conductivity
Authors: Guerrero Joshua , Deschamps Frédéric , Hsieh Wen-Pin , Tackley Paul
Published: March 2024

New insights from models of thermo-chemical mantle convection featuring heterogeneous thermal conductivity indicate that heat-producing element (HPE) enrichment in large low shear velocity provinces (LLSVPs) significantly impacts the long-term stability of these regions. Because the internal heating rate was more significant in the past, thermal conductivity's influence on thermal buoyancy (and bulk erosion) must have also been more substantial. As a consequence, the initial volume of the LLSVPs may have been significantly larger than their present-day volume. In numerical models, the evolution and stability of LLSVPs are often initiated by considering a dense and uniformly distributed layer on top of the core-mantle boundary. From energy balance calculations, a thin layer of LLSVP material (small mantle volume fraction) supports more HPE enrichment than a thicker layer (larger mantle volume fraction) to maintain the mantle's heat budget. For example, an initial layer thickness of 160km (~3% mantle volume) implies present-day HPE enrichment factors up to ~70 times the ambient mantle heating rate. This should be compared with more conservative factors of 10 to 20 for similar dense layer thicknesses employed in previous studies of thermochemical pile stability. Thus, HPE enrichment may have been significantly underestimated in earlier models of LLSVP evolution. Conversely, and assuming that LLSVPs formed from a much larger reservoir, HPE enrichment may be overestimated based on the present-day LLSVP volume. Our study considers LLSVPs with a primordial geochemical reservoir composition (consistent with an undegassed 4He/3He signature and HPE enrichment). We examine models of thermo-chemical mantle convection models with time-dependent internal heating rates and HPE enrichment (implied by the initial dense layer thicknesses). In this new context, we re-examine, in particular, the impact of a fully heterogeneous lattice thermal conductivity (derived from conductivity measurements of upper and lower mantle minerals). Furthermore, in light of recent developments with radiative conductivity, we also examine the added effect of a strongly temperature-dependent radiative conductivity component on the stability of LLSVPs. Using LLSVPs' present-day volume and core-mantle boundary coverage as a constraint, we recover potential initial conditions, heating scenarios, and thermal conductivity for an Earth-like model.
Upward transport in a canopy assisted by raindrop impacts on plant leaves
Authors: Gilet Tristan , Tadrist Loïc
Published: March 2024

The interception of raindrops by plant leaves induces a redistribution of water, nutrients, and micro-organisms, from the surface of these leaves to their surroundings. It consequently shapes the plant ecosystem. For example, in wheat fields (as in most major crops), splashing raindrops are the main mechanism of spore dispersal for fungal diseases at the epidemic stage, with severe consequences on crop yield. Surprisingly, the observed dispersal is not only downward (wash off / dripping) or outward (splash), but also upward, which may considerably speed up the fungus propagation. Other nutrients and microorganisms might also benefit from such upward transport external to the plant.In this work, we unravel an efficient and universal mechanism of upward transport: after a raindrop splashed on a plant leaf, the residual water on the leaf can be shot upward as the leaf springs back. We illustrate this phenomenon with several plant leaves. Then we present results obtained from systematic experiments with artificial leaves, thanks to which both the mechanics of rain-induced leaf motion and the fluid dynamics of leaf-induced droplet ejections are elucidated. We identify the range of mechanical properties of the leaf that makes upward shooting fully effective. Finally, we show that the efficiency of this upward transport increases more than proportionally with rain intensity. Its occurrence and role in shaping ecosystems will be largely amplified in the case of an increased frequency of extreme rain events.
Deciphering Hidden Ancient Human Physical and Chemical Markers through pOSL and  pXRF Analysis: A Case Study at Tel Burna
Authors: Ackermann Oren , Janovský Martin , Nikolskaia Polina , Fišer Jan , Anker Yaakov , Anker Yamm , Ben-Gedalya Tziona , Friedman Aharon , Hejcman Michal , Shai Itzhaq
Published: March 2024

As archeological sites are not isolated islands, they exert horizontal and vertical influence on their surrounding area. Therefore understanding the impact of these sites on their periphery becomes crucial.  Soil and sediments, as reliable historical archives, provide a unique opportunity to investigate these processes. Recent research has demonstrated that not all markers of human activity are visible, and a combination of physical and chemical methods, including pOSL and pXRF analysis, can provide insights into hidden past human signatures.Core drills conducted at the footslope of Tel Burna In Israel's archaeological site revealed an anthropogenic unit buried within the valley. This unit also contains a layer indicative of heightened anthropogenic activity, which could either signify the remnants of an ancient field's surface or the site's abandonment, followed by rapid site erosion. Given that these drills spanned from the slope of the Tell to the valley below, we were able to track the sediment's properties from the top of the site down to the valley. It was shown that the anthropogenic influence reduced with distance from the site, resulting in increasingly intricate patterns, suggesting multiple sources of sedimentation—both natural and anthropogenic. Furthermore, the study revealed a cycle of deposits that were transported to the site from the adjacent valley through human material transport activities to be subsequently eroded back into the valley due to natural processes. In summary, the ancient archeological site during its occupation and abandonment is still a physical feature that has been contributing to the landscape cycling processes.
Global and social factors impacting agricultural pond discontinuation in Japan
Authors: Watanabe Satoshi
Published: March 2024

Japan typically experiences a substantial annual precipitation, but its rugged topography and short rivers lead to rapid water runoff into the sea. Consequently, in many regions of Japan, agricultural ponds have served as the primary water reservoirs for irrigating rice paddies. It is estimated that there are approximately 150,000 agricultural ponds in Japan, most of which were constructed over a century ago. This study investigates the impact of climate change-induced shifts in rainfall patterns, as well as demographic changes such as declining birth rates and an aging population, especially in rural areas, on the status of agricultural ponds in Japan. Case studies conducted in various regions indicate that the discontinuation or abandonment of these ponds is primarily driven by reduced demand and the availability of modern irrigation facilities that can access water from larger, more efficient reservoirs compared to nearby agricultural ponds. Notably, small-scale ponds (less than 5,000 m3 in capacity), which constitute the majority of the total pond count, are being phased out due to considerations of utilization and management efficiency. Furthermore, recent increases in heavy rainfall events have underscored the risks associated with agricultural ponds, prompting stakeholders to opt for discontinuation or abandonment. This presentation delves into discussions on sustainable and effective water management, considering the environmental and socioeconomic factors influencing the fate of agricultural ponds in Japan. We also outline the survey methodology used, which emphasizes socio-hydrological aspects, and discuss the data analysis techniques applied to study the extensive number of agricultural ponds.
Effects of historical food production, consumption and trade on agricultural ammonia emissions and fine particulate matter (PM2.5) pollution worldwide: Implications for food-system mitigation strategies for a sustainable future
Authors: Tai Amos , Wong Avis
Published: March 2024

Fine particulate matter (PM2.5) pollution threatens human lives and wellbeing worldwide. Agricultural ammonia (NH3) is a key precursor of PM2.5. To examine how food consumption, production, and trade in different countries and regions affect global air quality, we derived a half-century (1962–2018) crop- and livestock-specific agricultural NH3 emission inventory and used it to conduct numerical experiments with the GEOS-Chem chemical transport model to estimate the impacts of food production, consumption, and trade in nine major food-importing and food-exporting countries or regions (China, India, Japan, Russia, Argentina, Brazil, Canada, European Union, USA) on PM2.5 pollution in themselves and in other countries via both atmospheric transport and food trade. We further performed sensitivity experiments by deducting NH3 emissions related to different food items that are consumed domestically vs. exported for each major country or region. We found that the rise in domestic food and feed crop consumption contribute significantly to PM2.5 pollution in China and India (up to ~40% of the total PM2.5 increase from all sources), among which ~40% is driven by meat production and consumption, highlighting the environmental impacts of dietary changes. We also found that even though China and India consume substantial amount of food imported from other countries, it is not a major contributor to PM2.5pollution in the exporting countries (e.g., ~1% of total PM2.5 in the food trading partners), mostly because the majority of domestic food demand is still satisfied by domestic production, and food import is diversified among a basket of exporting countries. Furthermore, agricultural NH3 is found to have a crucial modulating influence on PM2.5; e.g., the increase in PM2.5 due to agricultural NH3 could partly offset the decrease in PM2.5 induced by other anthropogenic emissions in North America after 1990, and such a phenomenon is expected for China as significant controls of non-agricultural emissions are underway. Our study highlights the significance of food consumption, production and trade in shaping PM2.5 worldwide, and it is important to incorporate sustainable food-system and agricultural strategies to simultaneously safeguard food security as well as the health of citizens and our planet.
Groundwater recharge and circulation processes in an arid mountainous area of northern Chile (30°S): Hydrogeochemical and isotopic study of the Arrayán basin, Coquimbo region, Chile.
Authors: Cárcamo Yerelin , Taucare Matias , Figueroa Ronny , Bresciani Etienne
Published: March 2024

Recent global hydrometeorological changes have increased in both duration and intensity due to anthropogenic impact. These changes are manifested, for example, in a generalized reduction of freshwater supply, threatening drinking water supply and socioeconomic development. In particular, in arid and semi-arid environments, precipitation and surface water resources are scarce and groundwater is a vital resource for sustaining life and fundamental for the integrity, development and conservation of ecosystems. Northern Chile (28-32°S) is characterized by transverse valleys and an arid climate, which has experienced an almost continuous sequence of relatively dry years since 2010, resulting in decreased flows and declining groundwater levels. Much of this area is characterized by plutonic and volcanosedimentary rocks. However, fractured hydrogeologic systems and secondary basins are poorly studied, and a lack of knowledge of local or regional groundwater flow paths exists in this region. Therefore, this study seeks to improve the scientific understanding of fractured hydrogeologic systems and their interaction with alluvial aquifers in secondary basins of the Coastal Cordillera (<2000 m a.s.l.) to improve long-term water management and contribute to ensure the sustainability of the resource. The study area is characterized by a mountainous morphology with high topographic gradients and narrow transverse valleys that give rise to numerous sub-basins dominated by the presence of plutonic and volcanosedimentary rocks. The hydrogeology of the studied area is characterized by hydrogeochemical analysis of 28 groundwater points and stable isotope analysis (δ18O and δ2H) at 35 points. The results reveal that hierarchical cluster analysis groups the samples according to the type of material storing groundwater, from bedrock or alluvial fill, while factor analysis evidence water-rock interaction processes in fractured aquifers areas and secondary evapotranspiration processes in alluvial aquifers. The calculated local meteoric water line shows the role of local precipitation in the recharge of the sub-basins. Recharge is distributed in alluvial and fractured environments, where it remains even though several years may pass without a recharge episode due to the large interannual variability of precipitation. Altogether, groundwater circulation is originated from local recharge, and the predominant processes are the dissolution of primary minerals in volcanosedimentary rocks and the precipitation of salts in alluvial aquifers.
Community-Driven Development of Tools to Improve AI-Readiness of the Open Environmental Data
Authors: Rao Yuhan "Douglas" , Redmon Rob , Khin Eric
Published: March 2024

As artificial intelligence (AI) and machine learning (ML) gaining broad interests in the Earth and space science community, the demand for AI-ready data can support the development of responsible AI/ML applications with open environmental data. Through a broad community collaboration under Earth Science Information Partners, we have developed an AI-readiness checklist as a community guideline for the development of AI-ready open environmental data. The checklist was initially based on an early draft of an AI-ready matrix developed by the OSTP Open Science Sub-committee but has been modified notably based on feedback from data users and AI/ML practitioners. The current version of the AI-readiness checklist can be used to holistically assess the documentation, quality, access, and pre-processing of a given dataset. The AI-readiness assessment result can be then summarized into a data card that provides human-readable metrics to assist users in determining if the dataset meets the user's need for their AI/ML development. The next milestone of this community-driven effort is to develop a community-driven convention by building on the existing data conventions and standards to fill the data management gap to support AI-ready data management. In this presentation, we will also showcase a collection of AI-ready climate datasets applying the AI-readiness checklist and data card concept to support AI/ML applications in climate sciences. The AI-readiness development process requires active community engagement with data repositories, domain scientists, and AI/ML practitioners to establish a flexible framework to ensure the rapid evolution of AI/ML technologies can be addressed in modern data management.
Millimeter wave radars: the way forward for remote sensing of ash plumes?
Authors: Nair Vishnu , Mohanathan Anujah , Herzog Michael , Macfarlane David , Ferguson Duncan
Published: March 2024

Ground-based observation of volcanic ash clouds after an eruption is currently done using weather radars which were originally designed for monitoring meteorological clouds. As ash particles and aggregates have different sizes and refractive indices compared to raindrops and ice crystals, certain parts of the volcanic ash cloud can go undetected by these low frequency weather radars. This can lead to incorrect predictions from the volcanic ash transport prediction models to the aviation industry; the field could benefit from higher frequency radars designed exclusively for ash cloud monitoring. However, the increased sensitivity to fine ash from high frequency signals comes at a cost of significant path attenuation as the wavelengths (in the order of millimeters) are comparable to the ash sizes, and any selection of frequencies should take into account the increased attenuation. In this talk we present a radar forward operator ‘SynRad’ that numerically simulates the radar measurement process and generates synthetic return signals. SynRad is used to evaluate the performance of three radar frequency bands (C-,Ka- and W-bands) to detect a volcanic ash cloud. The numerically simulated volcanic ash cloud of the Redoubt 2009 eruption serves as the case study. Results suggest that a dual-frequency radar with a C- and Ka-band is the best option to detect the predominantly larger ash particles and aggregates at the early stages of the eruption and the fine ash in the distal ash cloud during the later stages of the eruption respectively. The W-band radar undergoes heavy attenuation at all locations except for downwind of the ash cloud. 
Tracking dust sources and human health impacts around California's shrinking Salton Sea
Authors: Porter William , Miao Yaning
Published: March 2024

Windblown dust has long been an air quality and public health concern among residents living around California’s Salton Sea, a region characterized by serious socioeconomic and health outcome disparities. Dropping water levels and unique biogeochemistry within the Salton Sea water itself have raised concerns regarding the human health impacts of drying sediments exposed on shrinking shorelines, as well as potential lake spray emissions from the water surface. As particles emitted from different surface types can differ greatly in terms of composition, size distribution, and other properties, variability in the resulting health impacts of particulates reaching communities in the region may likewise be source dependent. Here I will share analyses of surface-specific health outcomes associated with windblown coarse PM around the region, as well as attempts to better understand and mitigate the unique issues linked to these emissions across the basin. I will further explore similarities and differences connecting evaporating inland lakes and seas worldwide, as well as some of the opportunities for sharing knowledge and tools to address air quality changes in the increasingly dry, dusty future facing the Salton Sea basin and other analogous regions.