bluuebunny/crossref_metadata_2025 huggingface dataset:
Developing Chorus Wave Model Using Van Allen Probe and Arase Data
Authors: Roy Alwin , Wang Dedong , Shprits Yuri Y , Feng Ting , Lepage Thea , Michaelis Ingo , Miyoshi Yoshizumi , Reeves Geoffrey D , Kasahara Yoshiya , Santolik Ondřej , Kumamoto Atsushi , Matsuda Shoya , Matsuoka Ayako , Hori Tomoaki , Shinohara Iku , Tsuchiya Fuminori
Published: March 2024

Chorus waves play an important role in the dynamic evolution of energetic electrons in the Earth’s radiation belts and ring current. Due to the orbit limitation of Van Allen Probes, our previous chorus wave model developed using Van Allen Probe data is limited to low latitude. In this study, we extend the chorus wave model to higher latitudes by combining measurements from the Van Allen Probes and Arase satellite. As a first step, we intercalibrate chorus wave measurements by comparing statistical features of chorus wave observations from Van Allen Probes and Arase missions. We first investigate the measurements in the same latitude range during the two years of overlap between the Van Allen Probe data and the Arase data. We find that the statistical intensity of chorus waves from Van Allen Probes is stronger than those from Arase observations. After the inter-calibration, we combine the chorus wave measurements from the two satellite missions and develop an analytical chorus wave model which covers all magnetic local time and extends to higher latitudes. This chorus wave model will be further used in radiation belt and ring current simulations.
Fiducial Reference Measurements for Soil Moisture (FRM4SM): recent progress in error source identification and traceable uncertainty budget calculation
Authors: Himmelbauer Irene , Aberer Daniel , Bader Nicolas , Preimesberger Wolfgang , Dorigo Wouter , Gibon François , Mialon Arnaud , Richaume Philipp , Tercjak Monika , Boresch Alexander , Crapolicchio Raffaele , Gruber Alexander
Published: March 2024

In situ soil moisture data is used as the main reference for the validation of satellite soil moisture products.  Although in situ measurements are often referred to as the “ground truth” and we have an understanding of the error sources, the magnitudes of the uncertainties associated with in situ measurements and methods to eliminate these uncertainties are hardly known. However, in order to achieve the best possible Return Of Investment (ROI) for a satellite mission, reliable and fully characterized in situ reference datatsets are crucial.ESA`s Fiducial Reference Measurement for Soil Moisture project (FRM4SM) was launched in 2021 to tackle the establishment of comprehensive and fully characterized, traceable uncertainty budgets for in situ soil moisture observations at the satellite footprint scale. The project aims to address the following scientific questions to facilitate the creation and exploitation of such Fiducial Reference Measurements (FRMs), using the International Soil Moisture Network (ISMN) as the in situ source and ESA’s Soil Moisture and Ocean Salinity (SMOS) mission as an example satellite product:(1) understand the status quo and means to establish an (SI-)traceable uncertainty budget for in situ soil moisture measurements(2) identify error sources that impact the in situ measurement(3) create quality indicators that allow to identify the most reliable “soil moisture FRMs” from the ISMN(4) verify and demonstrate the merit of these select soil moisture FRMs within validation case studies,(5) create protocols and procedures for the creation and use of such an FRM subset,  which are built upon community=agreed standards and practices(6) integrate the established FRM dataset and all developed validation methods into the freely-accessible Quality Assurance for Soil Moisture (QA4SM) online validation serviceIn this presentation, we will introduce the FRM4SM project and highlight our latest achievements and ongoing developments. Furthermore, we will discuss future directions, and give insights into challenges that need to be overcome in order to achieve a traceable uncertainty budget calculation for in situ soil moisture data at the satellite footprint scale.
DISCO: a low-cost Device-Instrumented Secchi disk for water Clarity Observations
Authors: Donini Gaia , Piccolroaz Sebastiano
Published: March 2024

Water clarity regulates light penetration in aquatic environments, influencing both physical and biological dynamics. Its influence extends to heat transfer within the water column, shaping the thermal structure of lakes. Photosynthetically Active Radiation (PAR) in the euphotic zone is the source of energy for light-dependent organisms, which are crucial for ecological balance. The ability to accurately assess water clarity is therefore important in several aquatic science contexts, ranging from data analysis and process interpretation to modelling. Common metrics used to quantify water quality include the vertical attenuation coefficient Kd,PAR, a measure of light penetration, and the Secchi depth (ZSD), a measure of water visibility. The enduring simplicity and cost effectiveness of the Secchi disk has made it a global standard for measuring water clarity for almost two centuries. In contrast, Kd,PAR is typically determined using expensive instruments designed to measure light in the PAR range. This discrepancy highlights the need for innovative yet cost-effective methods that integrate both types of measurements. In this contribution, we present DISCO, a low-cost instrument that combines the standard and globally used Secchi disk with light attenuation measurement supported by light sensors. DISCO retains the traditional shape of a Secchi disk but is equipped with light-dependent resistors (LDRs), which are used as light sensors both looking up and down. In addition to the LDRs, the disk is also equipped with low-cost temperature and pressure sensors, all connected to an ArduinoUNO board. After calibrating the sensors against commercial instruments, DISCO was tested in two mountain lakes together with high-resolution PAR, temperature and pressure sensors used as a benchmark. The results show that the proposed low-cost instrument is able to reproduce the shape of the light profiles with proper quantification of the light attenuation coefficients. Its affordable cost and ease of construction and use is expected to increase the ability to make measurements in locations where expensive instruments are not available, thereby extending the coverage of water clarity monitoring sites. This in turn has potential implications for wider in-situ calibration of remote sensing products. The prototype of DISCO will be shown at the poster session.
Causal Insights on the dynamics of Soil Moisture across Agro-climatic regions of India
Authors: Adigarla Yeswanth Naidu , Singh Sarmistha
Published: March 2024

Soil moisture stands as a pivotal element in land-atmospheric interplay, crucially affecting water, energy, and biogeochemical cycles. At a larger spatial scale, meteorological forces and land cover patterns significantly influence soil moisture dynamics. Prior studies primarily focused on investigating soilmoisture variability with soil texture and topography which have prominent influence factors at small spatial scales. Previous studies have employed various correlation techniques to explore these interactions however, correlation does not necessarily imply causation. Our study employs a causal discovery approach, specifically, Peter Clark Momentary Conditional Independence (PCMCI) using 8-day satellite-based gridded data from NASA's SMAP soil moisture, precipitation, leaf area index (LAI), evapotranspiration (ET), land surface temperature (LST), and vapor pressure deficit (VPD). The data was collected across diverse climate classes in India, and seasonal effects were removed to get valuable causal insights. Our results reveal that precipitation plays a predominant role in arid regions compared to humid ones, while LST and VPD significantly impact sub-arid regions. Notably, ET demonstrates substantial influence in the sub-humid regions. The maximum lag in causation is 2.5 to 3 months between the soil moisture and other variables. These findings significantly enhance our comprehension of soil moisture dynamics across various agro-climatic classes, thereby help in enhancing soil moisture predictions and improving agricultural drought forecasting.
Modelling Solar Energetic Particle event onsets in the turbulent heliosphere
Authors: Laitinen Timo , Dalla Silvia
Published: March 2024

Solar Energetic Particles (SEPs), accelerated during solar eruptions, are observed using instruments onboard spacecraft in interplanetary space, at a large distance from their source. As SEPs propagate in the solar wind, they are guided by the interplanetary magnetic field (IMF), which consists of a large-scale Parker spiral magnetic field superposed by turbulent fluctuations. The turbulence causes the SEPs to scatter along the magnetic field lines, resulting in some cases in delayed arrival of SEPs to spacecraft in interplanetary space. It also gives rise to meandering of field lines, which helps to spread SEPs across heliolongitudes, and eventually results in diffusive cross-field propagation of the particles. To investigate how turbulence affects SEP propagation and arrival to observing spacecraft in different locations in the heliosphere, we have developed a novel analytical model of the IMF, where the Parker spiral is superposed with Fourier modes that represent the turbulence. Unlike any previous models, our description reproduces the observed geometry for the main mode of turbulence, the so-called 2D mode, with both the magnetic field disturbance vector and the wavenumber vector normal to the background Parker spiral field. We use 3D test particle simulations to study the propagation of energetic protons in our new turbulent IMF description. Particles are injected close to the Sun and observables derived at different radial distances and heliolongitudes, representing the locations of near-Earth spacecraft as well as locations accessible to Solar Orbiter and Parker Solar Probe. We compare the SEP onset times obtained from our simulations to those obtained with a 1D focused transport model. We find that the turbulence prolongs the field lines, and thus when particle are simulated in our new IMF model, the SEP intensity onsets are delayed compared to those obtained by using a 1D focused transport model. Further, we find that onset delay depends on the longitudinal separation of the SEP source and the heliolongitude of the location where the observables are derived. We discuss the implications of our findings on current understanding of the sources and transport of SEPs.
Combined DAS and seismic nodes acquisition for shallow geophysics purposes around the Scrovegni Chapel in Padua, Italy
Authors: Nesterova Olga , Barone Ilaria , Cassiani Giorgio , Brovelli Alessandro , Rodríguez Tribaldos Verónica , Galtarossa Andrea , Schenato Luca , Palmieri Luca , Peruzzo Luca , Boaga Jacopo , Pavoni Mirko , Karbala Ali Haleh , Deiana Rita
Published: March 2024

Active and passive seismic measurements using conventional point sensors (geophones or seismometers) are usually performed to characterize the near surface in urban areas. However, high-resolution studies depending on the measurement scale, require hundreds to thousands of seismic sensors, which involves costly and time-consuming deployments. In recent years, DAS (Distributed Acoustic Sensing) has enabled standard optical fibers to be used as a continuous streamer of seismic sensors, allowing low-cost, high-resolution seismic surveys. The use of DAS technology has become standardized in the oil and gas industry. However, it is still under-exploited in shallow geophysics, where mainly dark fibers (unused telecom fibers) are exploited.Here, we show preliminary results from a seismic investigation using a combination of DAS and seismic nodes conducted in the vicinity of the Scrovegni Chapel in Padua, Italy. As the site includes buried archaeological remains from various eras, including a Roman amphitheatre, seismic measurements can be used for archaeological prospection. Moreover, to ensure the preservation of this cultural heritage, understanding the mechanical properties of the underlying soil is key for seismic risk assessment.Active seismic measurements were conducted on November 15, 2023 using a sledgehummer as the active source. Data were recorded using a Silixa iDAS interrogator unit along a 440 m long fiber optic tactic cable deployed in loop configuration inside three 20 m deep boreholes drilled around the chapel connected through a shallow (few cm) horizontal trench. A combination of 1C and 3C seismic nodes were also utilized as surface receivers along six receiver lines, deployed from the well heads and covering different azimuths. Shot points were located every second receiver position along each line. The acquired in-well DAS and surface node data was integrated for a first-arrival travel-time tomography study, allowing the retrieval of compressional-wave velocity vertical sections.
The present study represents the initial phase of our research efforts, which are being conducted partially within the framework of the USES2 project, which receives funding from from the EUROPEAN RESEARCH EXECUTIVE AGENCY (REA) under the Marie Skłodowska-Curie grant agreement No 101072599.
Toward automatic avalanche detection with Distributed-Acoustic-Sensing leveraging telecommunication infrastructure
Authors: Edme Pascal , Paitz Patrick , Fichtner Andreas , van Herwijnen Alec , Walter Fabian
Published: March 2024

Snow avalanches pose significant threats in alpine regions, leading to considerable human and economic losses. The ability to promptly identify the locations and timing of avalanche events is essential for effective prediction and risk mitigation. Conventional automatic avalanche detection systems typically rely on radars and/or seismo-acoustic sensors. While these systems operate successfully regardless of weather conditions, their coverage is often confined to a single slope or a small catchment (distances < 3 km).In our study, we demonstrate the feasibility of detecting snow avalanches using Distributed Acoustic Sensing (DAS) through existing fiber-optic telecommunication cables. Our pilot experiment, conducted over the 2021/2022 winter, involved a 10km long fiber-optic dark cable running parallel to the Flüelapass road in the eastern Swiss Alps close to Davos. The DAS data reveal distinct evidence of numerous dry- and wet-snow avalanches, even when they do not reach the cable, as confirmed photographically. We show that avalanches can be distinguished from other signals (e.g., vehicle traffic) using a frequency-dependent STA/LTA attribute, enabling their detection with high spatiotemporal resolution. These findings pave the way for cost-effective and near-real-time avalanche monitoring over extensive distances, leveraging existing fiber-optic infrastructure.
Remote Sensing: a stellar occultation video game based on ALTIUS
Authors: Berthelot Antonin , Baker Noel , Demoulin Philippe , Franssens Ghislain , Fussen Didier , Gramme Pierre , Mateshvili Nina , Pieroux Didier , Sotiriadis Sotiris , Dekemper Emmanuel
Published: March 2024

ALTIUS (Atmospheric Limb Tracker for the Investigation of the Upcoming Stratosphere) is an atmospheric limb mission being implemented in ESA's Earth Watch programme and planned for launch in 2026. The primary objective of the mission is to measure high-resolution stratospheric ozone concentration profiles. The Royal Belgian Institute for Space Aeronomy (BISA) is responsible for the development of retrieval algorithms for ALTIUS.In remote sensing, retrieval algorithms use the spectroscopic measurement data to determine atmospheric species concentrations. While being a crucial aspect of remote sensing, they are most often unknown to the public.On top of its scientific activities, BISA is also regularly involved in scientific outreach activities, including its own open doors days. In this framework, a video game in the form of an interactive ozone retrieval application was developed by the scientists. The user replaces the retrieval algorithm and tries to figure out the shape of the stratospheric ozone density profile using measured data. It is used to explain to the public the principle of atmospheric ozone density retrievals and in particular the concept of stellar occultation.Components typical of video games were added to make it more entertaining: a score is calculated based on the accuracy of the retrieved profile and the score is added to a wall of fame.So far, the game was used during BISA’s and ESA’s open doors days as well as during a scientific conference (Limb Workshop) held in Brussels. Several scientists involved in teaching to university-level students also showed their interest for such tools.A demonstration of the game will be performed and feedback from the various events where it was used will be given.
Frequency analysis of compound heat and wet extremes over Nepal
Authors: Neupane Bishnu Prasad , Guntu Ravi Kumar , Agarwal Ankit
Published: March 2024

Nepal faces a spectrum of climate-related challenges, such as floods, landslides, and droughts, causing substantial economic and environmental consequences. The country’s vulnerability to climate change is intensified by its geographic features and inadequate preparedness, underscoring the significance of studying compound extremes for water resources management and disaster mitigation. The susceptibility to climate change, coupled with geographic vulnerability heightened by extreme weather events, like floods and landslides, poses significant threats to Nepal’s socioeconomic development, necessitating further research. Studying compound extremes is crucial due to the escalating disastrous effects of cascading disasters, impacting agriculture, food security, and water resources. This study utilizes observed and model data to analyze compound heatwaves and extreme precipitation events, categorizing extreme precipitation as values surpassing the 95th percentile and defining heatwaves as three or more consecutive days with maximum temperatures exceeding the 95th percentile. Station data from 1981-2020 along with CMIP6 13 models data from 1951-1982 for past event analysis and from 2015 to 2100 for future projections reveal varying trends in heatwaves, extreme precipitation, and compound events across Nepal. Different models indicate diverse distributions of heatwaves and wet extremes, with some regions experiencing a decline in heatwave events in the past. The sensitivity of compound events to lagging periods is evident, resulting in a shift from 15 to 30 days and a subsequent increase in compound events. SSP scenarios project an overall rise in compound heatwaves and extreme precipitation in the future, emphasizing the risk of cascading disasters and urging stakeholders and governments to implement robust disaster risk reduction and management strategies. The study underscores the complexities of extreme events in Nepal’s climate data and model results, stressing the importance of considering spatial, temporal, and modeling factors for effective climate change impact adaptation and mitigation. 
The prediction of Ice SuperSaturated Regions and persistent contrail formation using weather data and in-flight observations.
Authors: Mackay Catherine , Marizy Corinne , Raguet Ioan
Published: March 2024

Aviation emissions contribute to climate change, one of the key contributors being contrail cirrus clouds. The importance of the impact is strongly dependent on their formation and persistence. A condensation trail - or contrail - is composed of ice crystals which form behind the aircraft engine exhaust at high altitudes when local weather conditions are favorable. The formation is also influenced by the engine technology and operating conditions, and by the fuel type. The contrail persists and evolves as long as it remains in an ice supersaturated region - or ISSR-, a local atmospheric air mass characterized by a low temperature and a humidity level that is saturated versus ice. Only persistent contrails are considered as having a climate effect.Weather forecast or reanalysis datasets were leveraged to understand if current data are sufficient to predict ISSRs and contrails, and to support the preparation of in-flight measurement campaigns. Statistics on ISSRs using multiple years of ERA5 ECMWF data will be presented for different months, and geographical areas. Results clearly help to identify geographical areas where the frequency of ISSRs is more important, as well as the seasonal, diurnal and vertical evolution of these frequencies. Using these results and incorporating information on annual meteorological changes, such as El Niño, a region and time of year was selected to conduct a contrail-related flight measurement campaign in Minnesota for two weeks of December 2023.During this period, NOAA GFS forecasts were used to identify ISSRs and plan aircraft flight paths. The forecast for a flight will be presented and compared to what was observed during this flight. The use of different resolutions to establish this forecast will also be discussed.
The Adiabatic Heat Flux through the Top of the Core of Ancient Vesta from High-P,T Resistivity Experiments
Authors: Lenhart Eric , Yong Wenjun , Richard Secco
Published: March 2024

Heat flow mechanisms in terrestrial planetary cores contribute to geophysical processes with broader significance such as the generation of a magnetic field. Thermal convective flow in a planetary core may be found with the combination of adiabatic heat flow estimates—which this study seeks to estimate—and thermal evolution models of total heat flow across the core-mantle boundary. Experimental data constraining the effects of light elements on these processes is still needed. In the case of asteroid Vesta, the core is expected to be composed of Fe alloyed with 13-16wt% S (Steenstra et al., 2019) and 1-2wt% Si (Pringle et al., 2013).To simulate the conditions of the early Vestan core, the resistivity of Fe alloyed with 16wt% S and 2wt% Si (Fe-16S-2Si) was measured at high pressures and into the liquid state. A 1000-ton cubic anvil press applied a static pressure of 2, 3, 4, or 5 GPa on the sample. The resistivity of Fe-16S-2Si was then calculated from the voltage drop and constant current across the sample at 300-2000 K along with post-experimental geometry measurements.With the electrical resistivity data, the thermal conductivity of Fe-16S-2Si is estimated using the Wiedemann-Franz Law. For 2-4 GPa, a thermal conductivity of 11+1.5 W/m/K is found. For the top of the core of ancient Vesta, an adiabatic heat flux of 0.3-0.4 mW/m2 is derived. These results indicate that the light elements expected in the Vestan core have a large effect on the thermodynamic properties, including more than halving the expected adiabatic heat flow. Since the total heat flux across the early Vestan core-mantle boundary has been previously estimated as >10 mW/m2 (Weiss et al., 2010), thermal convection alone may account for the magnetic dynamo in early Vesta with the presence of light alloying elements.References:Pringle, E.A., Savage, P.S., Badro, J., Barrat, J.-A., Moynier, F., 2013. Redox state during core formation on asteroid 4-Vesta, Earth and Planetary Science Letters, v. 373, p. 75-82.Steenstra, E.S., Dankers, D., Berndt, J., Klemme, S., Matveev, S., van Westrenen, W., 2019. Significant depletion of volatile elements in the mantle of asteroid Vesta due to core formation, Icarus, v. 317, p. 669-681.Weiss, B.P., Gattacceca, J., Stanley, S., Rochette, P., Christensen, U.R., 2010. Paleomagnetic Records of Meteorites and Early Planetesimal Differentiation, Space Science Reviews, v. 152, p. 341-390.
Examining the weakening of the AMOC using a Bermudan Stalagmite 
Authors: Forman Edward , Baldini James , Jamieson Robert , Lechleitner Franziska , Baldini Lisa , Breitenbach Sebastian , Macpherson Colin
Published: March 2024

While the Atlantic Meridional Overturning Circulation (AMOC) is understood to be weakening as a consequence of anthropogenic climate change, the precise onset of this decline remains subject of debate. There are two principal hypotheses surrounding the initiation of the slowdown: (a) it began in the mid-twentieth century in response to escalating atmospheric carbon dioxide concentrations, and (b) the trend started in the mid-nineteenth century, resulting from the increased freshwater fluxes associated with the end of the Little Ice Age (LIA). Here, we present a monthly resolved record of magnesium concentration extending back to 1456 derived from a Bermudan stalagmite. We use this proxy record to reconstruct sea surface temperature (SST) by calibrating the data to a previously published SST record, and with it derive an AMOC fingerprint spanning more than 550 years. From this we aim to decipher an estimate for the initiation of the observed AMOC decline within the context of its subsequent manifestations. 
Understanding unrest and dynamic triggering processes on Sierra Negra, Galápagos Islands.
Authors: Dunn Eleanor , Bean Chris , Lokmer Ivan , Bell Andrew
Published: March 2024

Dynamic earthquake triggering refers to the phenomenon where local seismic activity is induced by dynamic stress disturbances, originating from teleseismic earthquakes. An understanding of dynamic triggering on volcanoes offers a window into volcano stress states and seismicity initiation. Sierra Negra, a basaltic shield volcano situated on Isabela Island, Galápagos, has been the site of recurring episodes of dynamic triggering. Sierra Negra features a large elliptical summit caldera with a trap-door fault system and a magma reservoir extending 2km below the surface. Sierra Negra experienced an eruption in June 2018, characterized by a sequence of pre-eruption inflation, co-eruption deflation, and post-eruption inflation. The occurrence of dynamic earthquake triggering at Sierra Negra was observed in response to high magnitude teleseismic events from 2010 to 2018. The frequency of dynamically triggered earthquakes correlates with the increasing inflation of the magma reservoir. In this study, we aim to answer two questions: 1) How confident are we that the seismicity on Sierra Negra is dynamically triggered? And, 2) What is the location of these dynamically triggered events? Random simulations are used to calculate the likelihood that triggered events are related to teleseismic arrivals rather than being representative of local seismic activity. Results show that for the pre-2018 eruption, the likelihood that events are dynamic triggering is very high, compared to post-2018 eruption where events are more likely to be representative of local seismic activity. We only have access to a single station (VCH1) on Sierra Negra meaning the single-station location method must be used to locate all dynamically triggered events. To test and refine this method, 79 known seismic events are located using a full network from April 2018 – December 2018. Rotation of the 3-component VCH1 into the RTZ (radial-transverse-vertical) coordinate system is used to calculate the back-azimuth and the P-wave to S-wave delay is used to calculate the distance between event and station. 21 unknown dynamically triggered events are located in and around the caldera using this method. Looking forward we hope to understand the relationship between the location and timing of dynamic triggering, and its potential use in understanding volcano unrest state.
Locating charged regions in extensive layer cloud
Authors: Harrison R.Giles , Nicoll Keri
Published: March 2024

Extensive layer clouds are common in Earth’s atmosphere. They acquire charge at their upper and lower boundaries, from the vertical current flowing in the global atmospheric electric circuit. The quantity of charge collected is related to the current, the transition distance from clear air to cloudy air at the cloud boundary, and the background cosmic ray ionisation. The transition distance is the region in which a change in conductivity occurs, which determines the charge acquisition. This differs between cloud top and cloud base. At cloud top, the boundary transition distance is closely related to the temperature inversion, which can be less than the transition distance at cloud base. At cloud base, the transition distance depends on droplet growth rate and updraft speed. The combined effects of the local ionisation, current flow and conductivity gradient leads to droplet charging.Using instrumentation carried on enhanced meteorological radiosondes, the extent of the charged region in extensive layer clouds has been observed with specially developed cloud sensors operating at multiple optical wavelengths, simultaneously with the in situ electrical measurements. (Further, in some situations, ceilometer measurements of backscatter are also available). These soundings are compared with modelled profiles of droplet properties and layer cloud charges, for situations characteristic of mid-latitude and polar clouds. Effects of the droplet size distribution on the layer cloud electrification are also investigated, and responses to variations in cosmic ray ion production.Charging is known to affect some aspects of the microphysical behaviour of droplets, such as their evaporation and growth rates. This may in turn influence properties of layer clouds in the climate system.
A Real-time Monitoring System of Dissolved Nitrous Oxide, Methane and other Gases and their Isotopes in Aquatic Ecosystems
Authors: Shorter Joanne , Roscioli Joseph , Lunny Elizabeth , Wankel Scott
Published: March 2024

Coastal ecosystems are dynamic regions especially rich in diverse biological and geochemical interactions.  However, major gaps exist in our knowledge of the primary biogeochemical processes and the factors regulating their relative importance.  The study of the biogeochemical cycles of nitrogen and carbon in aquatic systems is important for understanding the fate of nutrients and other chemical components present there. Nitrous oxide (N2O) and methane (CH4), have important roles in these nitrogen and carbon biogeochemical processes as they are produced and cycled within coastal and ocean environments.  They are also significant greenhouse gases with major roles in climate change.  The gaps in our understanding of the distribution and dynamics of the underlying processes controlling their fluxes can be filled with the development and deployment of high-resolution spatial-temporal measurement methods.We have developed a field deployable, real-time, in situ system to quantify dissolved greenhouse gases (N2O and CH4 and their isotopologues) in aquatic ecosystems including coastal wetlands.  This measurement system consists of i) an array of permeable, hydrophobic probes that can be brought under a partial vacuum without intrusion of liquid water; ii) a collection protocol for efficiently drawing dissolved gases into the sampling system without isotopic fractionation; and iii) an interface of the probe array and the extraction and sampling system with real time analytical instrumentation.  By integrating an Aerodyne tunable infrared laser direct absorption spectrometer (TILDAS) into the measurement system, we can achieve real time determination of concentration and isotopic abundances of N2O and CH4.We have compared dissolved gases extracted from a variety of collected water samples including different tap water sources, ocean water, and wetland “swamp” water.  We observed higher N2O in the tap water samples compared to the ocean waters.  Swamp water collected from two areas of the wetland (i.e., still and moving water zones) had elevated CH4 and N2O, with the still water having higher methane and lower N2O than observed in water from area with movement.  We also compared dissolved N2O isotopologues with headspace in dosing experiments, achieving excellent comparisons of the 15N2O isotopic ratios (δ456, δ546) and site preference (SP = δ456- δ546) of dissolved N2O with the headspace.  Laboratory results as well as plans for field demonstrations in coastal areas will be discussed.
Balancing seasonality in decarbonising electricity systems worldwide
Authors: Gangopadhyay Anasuya , Masiwal Rajat , K Seshadri Ashwin
Published: March 2024

Decarbonizing electricity grids across the world will be increasingly impacted  by systematic seasonal variation in wind speed and solar irradiance as well as seasonally varying patterns of demand, more so in the context of progressive decarbonization of energy services such as winter heating. These seasonal variations are governed by local meteorology which also has large-scale manifestations impacting entire electricity grid systems. Using ERA5 reanalysis, we quantify the amplitude of seasonality in wind speed and solar insolation across the world and consider the impacts on grid scale generation. Owing to effects of seasonal evolution of solar insolation as well as the seasonal cycle of cloudiness, the seasonal cycle amplitude for solar insolation at the surface is much larger in higher latitudes. For horizontal winds, high seasonal amplitudes are experienced in global tropical monsoon regions and higher latitudes associated with meridional shifts in mid-latitude zonal winds. In general, wind power availability is much higher in high-latitude winters.Seasonal weather variation also drives electricity demand for heating and cooling, which is a major part of the total electricity consumption of many regions. While many large electricity consumers including China, US, India, and Brazil experience peak electricity consumption during summer, most European countries have higher demand during winter, giving a double peak structure for global monthly electricity demand. Many large electricity consuming countries experience nearly 40 percent variation in electricity demand between seasons. Solutions to bridge large seasonal variations in demand and generation, e.g. bulk energy storage, excess of wind and solar capacity, renewable portfolio design, and demand-side management present critical challenges.This paper will consider whether a portfolio of such solutions is adequate to balance seasonal variability in supply and demand. We will characterize the main patterns of seasonal load variability across countries, explore whether within-country wind and solar variability are well matched with these patterns, and consider the role of excess capacity and storage in bridging the gaps, in context of limitations of seasonal-scale demand side management. Bridging seasonal-scale gaps and mitigating the impacts of various manifestations of seasonality remains an important roadblock towards net zero electricity systems worldwide, and we will survey the most promising solutions to this challenge.
Aged carbon mineralisation from headwater peatland floodplains in the Peak District, UK
Authors: Alderson Danielle , Evans Martin , Garnett Mark , Worrall Fred
Published: March 2024

Floodplains are dynamic ecosystems that cycle carbon, which is both delivered from upstream catchment sources and produced in-situ by pedogenesis. These landforms are being progressively acknowledged as important environments of carbon processing, with the capacity for both substantial carbon sequestration in addition to acting as hotspots of carbon mineralisation. The balance between storage and release is dependent on a number of controls including landscape position, environmental conditions and soil characteristics. This study focuses on three headwater floodplains in a single catchment (approximately 10km in length), downstream of a highly eroded blanket bog peatland in the Peak District, UK. Aged organic carbon of peatland origin has been found in floodplains in this area based on prior research, and therefore we aimed to understand whether the allochthonous carbon was being mineralised in this context. We examined sediment cores and analysed the radiocarbon (14C) content of CO2 respired from the floodplain soils using a partitioning approach to scrutinise the depth and age relations of respiration in the individual floodplains and patterns of age distributions downstream. As such, we examined whether soil heterogeneity as a function of distance downstream and within individual floodplain profiles had an impact on age of respired CO2.Aged organic carbon was released from the upper and mid floodplain sites (14C ages of 682 and 232 years BP, respectively), whereas only modern dates were recorded at the lower site. The sedimentology was in accordance with the radiocarbon dates, suggesting primarily allochthonous deposition at the upper sites, but a dominance of in-situ soil development at the lower site. There was no age-depth relationship within individual floodplains, suggesting that the floodplain sediments were well-mixed and that aged organic matter was being processed both at the surface and at depth in the uppermost sites. An isotope mass balance mixing model indicated the control of two sources of CO2; recently fixed C3 organic matter and CO2 produced by methanogenesis. The results indicate that floodplains in a relatively narrow halo around eroding headwater peatlands could be important sites of aged carbon turnover originally derived from upstream sources, with those further downstream playing a different role. Reworked carbon does not transfer passively through the system and experiences periods of deposition where it can be subject to microbial action. In areas where organic carbon has previously been ‘locked up’ (e.g., permafrost regions) but is now under the threat of release due to climate change, this is an important consideration.
Exploring the efficient frontier in physical risk reporting
Authors: Bresch David N.
Published: March 2024

An increasing number of countries request large companies to disclose their physical climate-related risks based on regulations inspired by work of the Task Force for Climate-related Financial Disclosure (TCFD). Current reports do not lend themselves to direct comparison of physical risks across companies and by no means allow investors to build a portfolio optimised with respect to physical risks. Methods such as event-based probabilistic natural catastrophe risk assessment exist and would allow for aggregation of pertinent information, taking into account global diversification of risk. Convergence of TCFD-reporting towards such methods would enable investors and financial intermediaries to construct portfolios with respect to an efficient frontier in terms of physical risks. In the true spirit of TCFD, this would allocate capital towards companies best positioned to cope with the impacts of climate change and hence incentivise economic actors to strategically embrace climate adaptation. We present a fully transparent and easily replicable open-source and -access approach to construct such an efficient frontier and will discuss resulting risk-reward profiles and implications for corporate strategy development in the context of climate change.
Towards improving numerical sea ice predictions with data assimilation and machine learning
Authors: Gregory William , Bushuk Mitchell , Zhang Yongfei , Adcroft Alistair , Zanna Laure
Published: March 2024

In this presentation we highlight recent developments in the implementation of Machine Learning (ML) algorithms into the large-scale sea ice model, SIS2. Specifically, we show how a Convolutional Neural Network (CNN) can be used to systematically reduce global sea ice biases during a 5-year ice-ocean simulation. The CNN has been trained to learn a functional mapping from model state variables to sea ice concentration Data Assimilation (DA) increments. Therefore, during model integration, the CNN ingests information about the numerical model's atmosphere, ocean, and sea ice conditions, and predicts the appropriate correction to the sub-grid category sea ice concentration terms (without seeing any actual sea ice observations). We also show how this combined DA+ML approach leads to a natural framework for augmenting training data for neural networks; one which can lead to significant improvements in online performance, without the need for direct online learning. The bias reductions over the 5-year simulation period for this CNN correction scheme are even competitive with the bias reductions achieved from DA. These findings therefore suggest that our approach could be used to reduce systematic sea ice biases in fully coupled climate model predictions on seasonal-to-climate timescales.
GoNorth – Fieldwork in the Arctic Ocean
Authors: Simon Margit , Paasche Øyvind ,   GoNorth consortium
Published: March 2024

In 2009 the United Nations' Shelf Commission supported the Norwegian claim for an extended continental shelf north of Svalbard, into the Nansen Basin.Given that the scientific knowledge about the new-gained shelf areas is limited, it implied the necessity for new marine fieldwork and data-collection as this would provide expertise required by national authorities to reach sound and science-based decisions about the area in question.Hence the mission of the Norwegian GoNorth consortium was established. It continues to organize and launch a series of scientific expeditions deep into the Arctic Ocean to acquire new and essential knowledge about the oceanic areas, from the sea floor and subsea geology, through the water column, to the surface sea ice. The program is ambitious and strives for scientific excellence while at the same time being economically feasible and a key knowledge-provider. The program seeks, in other words, to bring Norway to the forefront as a responsible manager of the environment and the natural resources.The first GoNorth expedition was carried out in 2022 with Norwegian research vessel Kronprins Haakon heading for the Nansen Basin and the northern part of the Knipovich Ridge. In 2023, during the summer-expedition with the RV Kronprins Haakon, GoNorth scientists did, in collaboration with scientists onboard the German icebreaker vessel Polarstern, target one of the slowest spreading areas of the global system of mid-ocean ridges: the Gakkel Ridge. An exciting summer-cruise is planned for 2024 in collaboration with the Swedish icebreaker ship Oden with destination Morris Jesup Rise and the Yermak-plateau. Here we will introduce the project history and goals, its recent successful field campaigns and discoveries made as well as present the outlook for future Polar Ocean explorations. 
Forest Fires during COVID-19: Assessing Environmental Interactions and Fire Dynamics Amidst Reduced Human Intervention in India
Authors: Kate Rutuja , Bhattacharya Jayanta
Published: March 2024

This research delves into the dynamics of forest fires across various Indian regions, particularly during the unique COVID-19 lockdown period. The study's core focus is on the interaction between forest fires, climatic factors, and vegetation indices in a scenario of reduced human activity. It employs a multidimensional methodology, integrating satellite imagery and climatic data from periods before, during, and post-lockdown. The lockdown provides a critical opportunity to assess the impact of decreased human interference on forest fire patterns. Advanced statistical techniques are used to analyze the relationship between vegetation indices, fire occurrences, and meteorological conditions. This approach aims to uncover the underlying mechanisms driving these relationships, moving beyond simple trend identification. The research offers a nuanced perspective by differentiating natural factors from human influences. This distinction is vital in understanding the environmental dynamics during the lockdown. The findings have significant implications, offering insights for policymakers and environmentalists in enhancing forest fire management strategies. Emphasizing the need for a comprehensive understanding of environmental interactions, this study contributes to forming more informed and sustainable approaches to natural disaster management in the face of global challenges like climate change and pandemics.
Ecohydrological modelling to assist decision making for land- and water management: applications from The Netherlands
Authors: Clevers Sharon , Aggenbach Camiel , Bartholomeus Ruud , Nijp Jelmer
Published: March 2024

Ecohydrological modelling to assist decision making for land- and water management: applications from The NetherlandsBiodiversity in nature areas is severely declining on both global and European levels. Many species and ecosystems are threatened by climate change, desiccation due to lowering groundwater levels and high nitrogen deposition. The Natura 2000 Network, a European-wide network of nature conservation areas, has been created to preserve and restore biodiversity. Ecohydrological processes are a key factor in the conservation of vegetation in nature areas. The relative impact of hydrological measures on biodiversity and vulnerable species is poorly understood in these nature areas, especially when uncertainty associated with climate change is taken into account. This knowledge gap delays decision making for land and water management. This study demonstrates a ecohydrological modelling approach to quantify the impact of hydrological changes on  vegetation.In recent years, research has been done at KWR Water Research Institute in collaboration with several partners [1] to construct ecohydrological models that include the process-based relationships between water-related habitat factors and vegetation types. These models are currently applied at various spatial scales (local to national) to support decision making. The Water Vision Nature (WWN, in Dutch: Waterwijzer Natuur) is a tool including the model PROBE (PRObability-Based Ecological target model) to simulate the impact of water management, climate change and nitrogen deposition on terrestrial vegetation. PROBE uses the waterlevel output of a groundwater model to calculate the important habitat factors oxygen and transpiration stresses of the vegetation. Additionally, the habitat factors nutrient availability and acidity are derived from output of the hydroloigical model and soil factors. Next, these values are translated into vegetation indicator values for moisture, nutrients and acidity, respectively, by using empirical relationships. PROBE uses these values to predict the occurrence of vegetation types and the botanical nature value of these vegetation types.To analyse the potential impact of the ecohydrological outlined approach on decision making in land and water management, WWN has been applied to evaluate local restoration and management plans of Natura 2000 areas in the Netherlands. These studies show that the process-based ecohydrological model PROBE is a useful method to analyse future management scenarios in nature areas by taking into account both water management measures and climate change scenarios.

[1] Wageningen University en Research , Stowa, Nutrient Management Institute (NMI) and Hoefsloot Spatial Solutions (HSS)