bluuebunny/crossref_metadata_2025 huggingface dataset:
Challenges in applying an empirical modelling approach for resilience of soil carbon functioning
Authors: Todman Lindsay , Adekanmbi Adetunji Alex , Zou Yiran , Shu Xin , Pathan Shamina Imran , Sizmur Tom
Published: February 2023

Soils function under highly variable weather conditions which can be challenging to capture in models and metrics. A previous metric of soil resilience used an empirical model to characterize a key soil function (substrate induced respiration) and how this changed over repeated stress cycles. Here, we apply this laboratory and modelling approach to soils from a plot experiment in which cover crops (single species monocultures and 4-species polycultures) were grown over the summer in between autumn sown cash crops in a cereal rotation to compare their resilience. Open Top Chambers (OTCs) were also used to warm the soil surface of part of each plot to mimic climate change impact. Soil samples were collected from these experimental plots after harvesting the cereal crop and we assessed barley grass powder substrate induced soil respiration (a measure of soil microbial function) after 0, 1, 2, 4, and 8 wet/dry cycles imposed in the laboratory. In contrast to previous studies, the initial drying and rewetting stress did not markedly decrease or alter the substrate induced respiration profiles, suggesting that the soil was highly resilient to this stress. Warming slightly reduced soil microbial function after 8 repeated wet/dry cycles, relative to microbial function after 0 wet/dry cycles. However, cover crops, and particularly the 4-species cover crop polyculture, increased soil microbial function significantly after 8 repeated wet/dry cycles, relative to microbial function after 0 wet/dry cycles. The modelling approach suggested high resilience of this soil function in all plots, but did not detect any differences in the resilience of soil carbon functioning for soils from the different plots, but it was unclear whether this was due to lack of sensitivity of the approach. This further emphasizes the challenges in quantifying the ‘resilience’ of soil functioning as it is highly dependent on context.
Ambient Noise and Earthquake Surface Wave Phase Velocity Tomography of the South American Lithosphere
Authors: Quadros de Souza Lúcio , El-Sharkawy Amr , Assumpção Marcelo , Meier Thomas
Published: February 2023

The development of new automated techniques to measure earthquake-based interstation phase velocities allows for more detailed imaging of the South American Lithosphere. We calculated Rayleigh-wave phase velocities using the earthquake records from 1022 broadband seismic stations (South America, Antarctica and the Caribbean) operated between 1990 and 2020. A total of 1.069.259 earthquakes were selected with the following criteria: (1) events aligned within 10° of the 2-station great circle path; (2) a linearly increasing minimum magnitude between 4 and 6 Mw as a function of the epicentral distance; (3) maximum magnitude of 8 Mw; and (4) epicentral distances between 2.5° and 30°.We used surface wave fundamental mode dispersion curves calculated automatically using a new implementation of the 2-station cross-correlation method and a number of strict quality criteria, which include the selection of the phase velocity curves based on a 3D background model, curve smoothness and width of the considered frequency range. Following this process, we obtained 46.763 broad-band dispersion measurements between 4 and 315 s. Finally, the single-event dispersion curves were averaged for each interstation pair with associated error estimates and further quality control comparing results from both directions, evaluating smoothness and the standard deviation of the resulting dispersion curve.The dispersion curves were simultaneously inverted for isotropic and anisotropic (2ψ and 4ψ) phase-velocity maps parameterized on a triangular grid with a knot spacing of 30 km.The isotropic phase velocity maps at periods of 15 and 30 s indicate around 8% high-velocity perturbations in the regions of: (1) cratonic blocks of the South American platform (Brazilian Shield, São Francisco and Rio Apá cratons); and (2) the basement of the Pantanal basin (a 500 m thick sedimentary basin) possibly related to a high-velocity lower crust. For those periods, we also observed between -8 to -4% low-velocity perturbations associated with the Andean Mountain range root below the Altiplano Boliviano region (central Andes), the forelands of the Andes. The Paraná, Chaco and Parecis intracratonic basins also have lower velocities with relation to the neighboring cratonic areas.At periods of 60 and 100 s, we observed around 4% high-velocity perturbation associated with the deep roots of the oldest region of the Amazonian craton (eastern area of the Brazilian Shield) and the São Francisco craton. Azimuthal anisotropy is laterally and vertically variable within the South American lithosphere. At longer periods, fast directions are pointing to asthenospheric flow guided by LAB topography, for example below the Pantanal basin (central-west Brazil).For the next steps, we plan to jointly invert for a isotropic and anisotropic 3D model using earthquake and ambient noise dispersion curves with Rayleigh and Love waves.
Cyclostratigraphic investigations with special emphasis on half-precession signals using XRF-data from ODP Site 663 (Eastern Equatorial Atlantic)
Authors: Ulfers Arne , Zeeden Christian , Kaboth-Bahr Stefanie , Westerhold Thomas , Röhl Ursula
Published: February 2023

The characteristics of half-precession (HP) cycles (~9,000 - 12,000 years) are still poorly understood, despite their appearance in numerous records. Previous studies on European terrestrial and marine records indicate a connection of the HP-signal to low latitudes. Here, we investigate HP-cycles in equatorial regions to study the assumed origin of this signal.Spectral analysis, evolutive approaches and correlation techniques are used on records from ODP Sites 662 and 663 to identify the HP-signal in elemental ratios reflecting e.g. terrigenuous input and/or bioproductivity. Filters have been designed to remove the classical orbital cycles (eccentricity, obliquity, precession), in order to isolate the HP-signal and to determine the temporal evolution of its presence and amplitude.We present first results of a larger project which has the overall objective to characterize the HP-signal across the Mid-Pleistocene Transition (MPT) at Sites 662 and 663. Over the course of the MPT, the ~100 kyr-eccentricity cycles supersede the 41-kyr obliquity as the primary driver of climate forcing. As precession is modulated by eccentricity, a similar relationship may be assumed for HP and eccentricity. Our preliminary analyses show an enhanced HP-signal in the younger, 100-kyr eccentricity world, but also in the late MPT which is partly influenced by the 41-kyr obliquity cycle. Cyclostratigraphic investigations of high-resolution XRF data will provide a clearer insight into the presence, amplitude and role of HP during the MPT and the late Pleistocene.
Inconsistency and violation of causality in Bayesian inversion paradigms
Authors: Mosegaard Klaus
Published: February 2023

Probabilistic formulations of inverse problems are most often based on Bayes Rule, which is considered a powerful tool for integration of data information and prior information about potential solutions. However, since its introduction it has become apparent that the Bayesian inference paradigm presents a number of difficulties, especially in the phase where the problem is mathematically formulated. Perhaps the most notable difficulty arises because Bayes Theorem is usually formulated as a relation between probability densities on continuous manifolds. This creates an acute crisis because of a problem described by the French mathematician Joseph Bertrand (1889), and later investigated by Kolmogorov and Borel. According to Kolmogorov's (1933/1956) investigations, conditioning of a probability density is underdetermined: In different parameterizations (reference frames), conditional probability densities express different probability distributions. Surprisingly, this problem is persistently neglected in the scientific literature, not least in applications of Bayesian inversion. We will explore this problem and show that it is a serious threat to the objectivity and quality of Bayesian computations including Bayesian inversion, computation of Bayes Factors, and trans-dimensional inversion. Another difficulty in Bayesian Inference methods derives from the fact that data uncertainties, and prior information on the unknown parameters, are often unknown or poorly known. Because they are required in the calculations, statisticians have inventedhierarchical methods to compute parameters (known as hyper-parameters) controlling these uncertainties. However, since both the data uncertainties and the prior information on the unknowns are supposed to be known 'a priori', but are calculated 'a posteriori', this creates another crisis, namely a violation of causality. We will take a close look at the consequences of this mixing of 'prior' and 'posterior', and show how it potentially jeopardizes the validity of Bayesian computations. 
Effect of energetic particles on the atmosphere of terrestrial exoplanets
Authors: Iro Nicolas , Grenfell John Lee , Herbst Konstantin , Sinnhuber Miriam , Taysum Benjamin , Bartenschlager Andreas
Published: February 2023

M-dwarf stars have been preferred targets of exoplanet search due to the favourable parameters of the system for remote characterisation. However, planets in the habitable zones of these stars are expecting to experience intense radiation.
We present the INCREASE project (INfluence of strong stellar particle Events and galactic Cosmic Rays on Exoplanetary AtmoSpherEs), aiming at modelling the effect of energetic particles on the atmosphere of terrestrial exoplanets. The INCREASE model suite is an almost self-consistent simulation chain coupling the state-of-the-art magnetospheric and atmospheric propagation and interaction models PLANETOCOSMICS (Desorgher et al. 2006) and AtRIS (Banjac57 et al. 2019) with the atmospheric chemistry and climate models 1D-TERRA (e.g., Wunderlich et al. 2020) and ExoTIC. Finally, spectral characterisation is done using the GARLIC line by line radiative transfer model.
By combining these models, we are able to constrain the habitability of such planets, the stability of their atmosphere as well as simulating observational features.
Geomorphological signatures of extreme wave events: a literature review of studies on coastal boulder deposits within the Mediterranean Region
Authors: Gauci Ritienne , Causon Deguara Joanna , Inkpen Rob
Published: February 2023

The presence of boulders and coarse clasts on rocky coasts has been the subject of numerous studies worldwide, exploring a wide range of meteo-marine settings and site-specific geological contingency. Such coastal boulder deposits (CBD) are considered to be geomorphological signatures of erosional and depositional processes by wave action and hence, considered as important indicators in reconstructing historic impacts of wave climates and other extreme events. The scope of this paper is to review the breadth and depth of scholarly works in geomorphology (but not only), carried out on boulder deposits within the coastal regions surrounding the Mediterranean Sea. Extreme wave events are a source of hazard that may have major negative impact on human life and a vast spectrum of economic activities across many coastal Mediterranean states. Population demographics indicate an increase in the number of people living in coastal cities around the Mediterranean region, from 100 million in 1980 to 150 million in 2015 and is expected to exceed 200 million by 2030. Although population density varies across countries the highest densities are found in port cities, mainly due to higher economic opportunities associated with these areas. The aims are to analyse how the focus of studies has evolved over time in response to new findings, observations and technological advances. Understanding how such mechanisms function in terms of wave dynamics and boulder detachment and transportation may assist in the prediction of hazards and erosion. This can be done both in the short term by combining data from weather forecast and wave models and for longer timeframes by considering the cumulative effect of yearly storms, the stronger fifty year or hundred-year storm and other exceptional events.
The effect of removal of all non-functional turf in Las Vegas: tradeoffs between water conservation, excessive heat, and storminess
Authors: Mejía Valencia John Freddy , Henao Juan , Saher Rubab
Published: February 2023

This study shows the unintended tradeoffs of water conservation strategies in the City of Las Vegas. We used the Weather and Research Forecasting model coupled with a multilayer Urban Canopy Model, and forced with the Local Climate Zones from WUDAPTv2, to carry out cloud-resolving simulations aiming to estimate the impacts of city-wide turf removal. Results show that removing the turf, which removes most of non-functional urban irrigation needs, significantly warms up surface temperature via surface energy rebalancing by reducing latent heat and increasing sensible and ground heat fluxes. A striking result is that the increase in sensible heat also increases boundary layer instability favoring more and longer lasting clouds and invigorating afternoon storms. The enhanced afternoon storms tend to cool the surface temperature, but the turf removal net warming impact remains. We also used the model to show how climate intervention scenarios based on cool roofing and pavement strategies can ameliorate the underlying turf removal consequences.
Meteorological variability and regional pollutant distributions during the summer 2022 ACROSS/PANAME campaign
Authors: Beekmann Matthias , Siour Guillaume , Di Antonio Ludovico , Foret Gilles , Meleux Frederic , Colette Augustin , Rosso Amandine , Di Biagio Claudia , Cuesta Juan , Formenti Paola , Gratien Aline , Haeffelin Martial , Kotthaus Simone , Masson Valery , Michoud Vincent , Cantrell Christopher
Published: February 2023

The international ACROSS (Atmospheric ChemistRy Of the Suburban forest) intensive field measurement campaign (supported by the Make Our Planet Great Again initiative) took place from June 13 to July 25 2022 in and around the Ile-de-France during an exceptional hot (more than 3°C above the climatological mean for France) and dry summer season. This work will provide a broad classification of weather conditions that occurred during the campaign, useful for further analysis of observations and simulations. Weather scenarios will be analysed in terms of synoptic weather situations, relating transport patterns (regional advection to the Ile-de-France region, plumes from Paris agglomeration), temperature and relative humidity evolution. During the June-July 2022 period, several distinct weather and pollution patterns occurred, among which: (1) two strong heatwaves, with large photochemical activity promoting secondary pollutants build-up (O3, SOA), (2) advection of relatively clean oceanic air masses, and (3) Saharan dust and intense forest fire events with dust and fire aerosol advection to the Ile-de-France region. The analysis is based on meteorological data from several models (GFS, WRF, ARPEGE, AROME) and observations, pollution forecasts from the French Prev’Air system (http://www2.prevair.org/), and from the AirParif Esmeralda platform (http://www.esmeralda-web.fr/accueil/)  that have been used for the airborne campaign support. In addition, dedicated simulations with the CHIMERE model (see companion abstract by Di Antonio et al. for this session), and major pollutant observations by air quality networks, from satellites, or performed within ACROSS will be used to analyse how meteorological conditions and weather patterns impacted the spatial distributions of major primary and secondary chemical species. Especially tracers of anthropogenic and biogenic emissions and photochemical activity (O3, PM2.5, OA, BC, NOx, BVOC) will be analysed.  Keywords: Meteorology, pollutant distributions, transport patterns, ACROSS, MOPGA  
Optical thermometry to characterize heat transport in permeable porous media
Authors: Rashed Arwa , Klepikova Maria , Rousseau Gauthier , Gomez Francesco , Heyman Joris , Fond Benoît , Méheust Yves
Published: February 2023

The study of heat transport in porous media has recently attracted a lot of attention due to the wide range of industrial and geological applications, yet the impact of the structural heterogeneity of naturally occurring aquifers on their hydraulic and thermal properties is often disregarded. In that regard, a novel application of phosphor thermometry to porous media is proposed with the aim of examining under which conditions the validity of existing thermal transfer models in complex natural saturated porous media can be questioned. This experimental technique relies on monitoring the temperature-dependent luminescence properties of solid phosphor particles seeded into the fluid as tracers, using light sources and cameras. It offers the possibility of characterizing quantitatively the interaction between flow and heat transport processes at the pore scale in transparent analog porous media, with minimal interference and from spatially-resolved measurements, hereby overcoming the technical limitations of current experimental techniques, which are constrained to point temperature measurements.Here, as proof of concept, we present a demonstration experiment performed on a slow-moving flow in a synthetic porous medium with a heterogenous size distribution, and using YAG:Cr3+, a thermographic phosphor with a temperature sensitivity exceeding 0.3%/K [1]. The measurements are performed using a modulated light source and are recorded at a sampling rate of 1 kHz during continuous injection of an aqueous solution which is initially at a constant temperature, different from that of the resident solution. The results show the dynamics of the spatial temperature distribution in the porous medium with a precision of ±0.3°C.[1] J. L. Bonilla and B. Fond, "Phosphor thermometry using the phase-shift method: optimization and comparison with decay time method," 2022.
Challenges in Developing a Software Architecture for a National Research Data Infrastructure in Earth System Sciences
Authors: Henzen Christin , Degbelo Auriol , Nüst Daniel
Published: February 2023

Research data infrastructures (RDIs) are evolving and driven by diverse initiatives ranging from international to local, e.g., institutional scales, who try to build sustainable and useful services. The German national data infrastructure for Earth System Sciences (NFDI4Earth) aims to support researchers in 1) discovering and exploring relevant data sources, 2) data publication and curation, 3) solving research data management problems and 4) creating and publishing information products. In the development of the  software architecture for NFDI4Earth, we face challenges of computational, social, cultural, and strategic nature. Here, we are going to present an overview of these challenges and early outcomes and to reflect  first lessons learned from the initial concept and development phase of the NFDI4Earth architecture.Starting with the (meta) data layer, the landscape of existing ESS services and repositories is diverse and features various metadata and data, like governmental (meta) data following INSPIRE, OGC, and ISO19xxx. This diversity demands harmonising and linking concepts that fit to standards for metadata, data and services, such as OGC APIs or ISO19xxx, as well as to Semantic Web concepts, e.g., FAIR Digital Objects, and provide extension points for (newly developed) specific formats. At the same time, the software stack and technologies of the business layer should consider interoperability, openness and sustainability aspects while providing a flexible solution to manage the distributed metadata. Moreover, in our case, activities on developing (meta) data and business layer concepts also include coordinating a software developer team with different scientific and technological backgrounds spread across several institutions.NFDI4Earth is located in a dynamic landscape of ESS services and repositories which are often not sustainably funded. Hence, we need to implement  practices and collaborations to link or integrate further software, services, and information products so that an up-to-date living and evolving architecture serves the needs of researchers.
Monitoring flocculation during a deep-sea mining test in the Clarion-Clipperton Zone, eastern equatorial Pacific Ocean
Authors: Diaz Melanie , Stigter Henko , Gillard Benjamin , Gazis Iason-Zois , Mohrmann Jochen , Heger Karl , Baeye Matthias , Thomsen Laurenz , Greinert Jens
Published: February 2023

Where fine-grained marine sediments are being brought in suspension and become subject to transport by currents, aggregation of cohesive primary particles (flocculation) can occur. By changing the inherent particle properties, flocculation processes play an important role in speeding up settling and redeposition of sediment particles. However, while numerous laboratory experiments have been conducted to understand properties and behavior of flocs, so far, there is not yet an appropriate method to monitor flocculation in-situ. Gaining a better understanding of the flocculation process and how it will affect the dispersion of man-made sediment plumes is important to assess the impact of human activities on the environment, for example in the context of deep-sea mining or offshore dredging.In this study, the inherent acoustical and optical properties of sediment particles are studied using in-situ plume monitoring data collected by the MiningImpact2 project consortium during the first deep-sea mining trial of a pre-prototype polymetallic nodule collector vehicle. The trial was conducted in April 2021 at 4500 m water depth in the Clarion-Clipperton Zone (eastern equatorial Pacific Ocean) by the Belgian contractor DEME-GSR. During this trial, one of the main goals was to monitor the spatiotemporal evolution of the sediment plume generated by the mining vehicle. For this purpose, numerous sensors were deployed around the test area including ADCPs of different frequencies, OBSs and deep-sea particle camera. In this study, the main interest is to use this dataset to gain knowledge on the variability of particle properties and to monitor flocculation in the generated plume.The monitoring array of sensors proved successful in measuring the dispersion of the plume around the mining site. In the data recorded in the plume, a gradient in optical and acoustic response was found, suggesting a change in inherent particle properties such as their size and shape induced by flocculation. The evolution of particle size as inferred by the particle camera recordings (PartiCam) corroborated this finding. In combination with currents and environmental measurements, this dataset provided valuable information to better understand the flocculation process.
Heterocyte glycolipids: novel tools to obtain high-resolution climate and ecosystem data from lacustrine archives
Authors: Bauersachs Thorsten , Russell James M. , Schwark Lorenz
Published: February 2023

Lacustrine sediment sequences represent highly valuable, continuous records of continental climate and ecosystem change. As such, they provide vital information on both the timing and magnitude of long-term climate trends as well as abrupt climate change events and associated biotic responses. Assessing this information, however, is often not straight forward as many conventional lipid-based temperature proxies are affected not only by temperature but also other environmental parameters. Here, we show that the distribution of heterocyte glycolipids (HGs), which are synthesized by N2-fixing heterocytous cyanobacteria and abundantly present in modern freshwater environments, are strongly correlated to lake surface water temperatures. We used these components, in form of the novel organic temperature proxy HDI26, to reconstruct climate variations in tropical East Africa and simultaneously study the impact of climate change on the frequency and intensity of cyanobacterial blooms using a sediment record from Lake Tanganyika (Tanzania). HDI26-reconstructed surface water temperatures varied from ~22 °C to 26 °C in Lake Tanganyika over the last 40,000 years. Lowest temperatures were observed during the Last Glacial Maximum, which is followed by a 3 to 4 °C deglacial warming to yield highest temperatures in the Late Holocene. This general warming trend is interrupted by up to 1 °C cooling during abrupt climate change events (e.g. Younger Dryas). Lipid-based reconstructions of past cyanobacterial activity indicate that although continuously present in Lake Tanganyika, cyanobacteria only became bloom-forming in the late Holocene and in particular during the last 200 years. Our data thus provides new insights and quantitative estimates on Pleistocene to Holocene climate changes in tropical East Africa and associated ecological responses. Given that heterocyte glycolipids are present ubiquitously in polar to tropical lakes and that they have been identified in lacustrine sediments of Early Cenozoic age, the HDI26 and other HG-based indices provide valuable novel tools to extract the highly sensitive climate and ecosystem information that is stored in sediments of lakes worldwide.
Insights into the daily emissions and consumptions of methane and nitrous oxide from tropical tree stem surfaces
Authors: Bréchet Laëtitia M. , Salomόn Roberto L. , Daniel Warren , Stahl Clément , Burban Benoît , Goret Jean-Yves , Steppe Kathy , van Haren Joost , Saleska Scott , Janssens Ivan A.
Published: February 2023

Methane (CH4) and nitrous oxide (N2O), critical climate-forcing trace gases, are rising sharply in the atmosphere. The estimate for their natural emissions remains uncertain because of mismatches between bottom-up (from flux measurements to process-based models) and top-down (from satellites to inversion models) approaches. Besides soils, trees can exchange CH4 and N2O with the atmosphere (either emitting or taking up), potentially acting as conduits for transporting large amounts of soil-produced CH4 and N2O. However, tree CH4 and N2O fluxes are not included yet in models, mainly because of a lack of detailed understanding of the sources and drivers of their temporal variation. This holds particularly true in tropical forests where high-frequency measurements are rare.We first hypothesized that, although on well-aerated upland forest soils, trees contribute to ecosystem CH4 and N2O fluxes, with seasonal CH4 and N2O flux dynamics being reversed between the stems and soil. Second, we postulated that, at the daily scale, circadian rhythms of tree physiology affect stem CH4 and N2O fluxes. We investigated these hypotheses by examining the high-temporal-resolution fluxes of CH4 and N2O of three tropical trees. We measured fluxes from their stems (and adjacent soils) with an automated chamber system and tree and environmental variables (i.e. tree growth, sap flux density, tree water deficit, stem and soil temperature, stem and soil water content) over 20 months in a tropical forest, in French Guiana.Long-term series of stem CH4 and N2O fluxes not only revealed that stems emitted CH4 and consumed N2O but also that flux variability was greater between tree individuals than seasons. We also found that stem CH4 and N2O fluxes were not linked to soil fluxes and exhibited diurnal patterns, with stems being greater emitters of CH4 and lower consumers of N2O in the early morning than at midday. CH4 and N2O peaks at sunrise suggest that gases accumulated in the stem at night when there was no gas flow and were vented out as soon as the pressurized flow started, following daily tree water dynamics. These preliminary results showed clear evidence of the need for continuous CH4 and N2O flux measurements in tropical forests to disentangle tree-mediated CH4 and N2O transport; more study is required to determine the relative importance of wood microbial organisms and tree traits for regulating gas transport through their aboveground parts.
Acceleration of Daily Land Temperature Extremes and Link to Land Forcing
Authors: Huntingford Chris , Cox Peter , Rithie Paul , Clarke Joe , Williamson Mark
Published: February 2023

We analyse a large number of Earth System Models (ESMs) and find that there is some evidence that the temperatures of extreme events are rising faster than local background rises in mean summer temperatures. We find this to be true for almost all land regions when analysing the SSP585 scenario and for the decades from now until the end of the 21st Century. We find strong correlations between the level of acceleration and upward trends in sensible heat fluxes. In the few tropical regions where there is less correlation, we instead find a link to background latent plus sensible heat, which acts as a proxy for overall available energy. We then study extreme acceleration in the contemporary period, in both ESMs and ERA5 data. We find in these circumstances particularly strong evidence of faster warming of extreme events, but only for selected regions. We suggest this is a consequence of highly regional effects such as aerosols. Our analysis hints that as atmospheric composition changes move towards alteration by greenhouse gases only, there will be a more general globally-applicable occurrence of high-temperature extremes, with their mean increase more than the more general background warming levels.  
Detecting Climate-Driven Increases in Interannual Net Primary Productivity of Forest Ecosystems
Authors: Kim Sukyoung , Choi Jaeyeon , Park Chan
Published: February 2023

Under Paris Agreement, carbon sink at the national level has been reported to the international community. There are various attempts to improve the accuracy of reporting on the national carbon sink. Especially, IPCC has discussed the necessity of reports distinguished by artificial and natural factors’ effects on the carbon sink based on the Interannual variability (IAV) (IPCC, 2019). However, there are no clear methods to identify the effect of artificial factors. The forest, which has a high density of vegetation, is important as the place that absorbs carbon. The accelerated photosynthesis process of forests by climate change can lead to changes in vegetation productivity and carbon sink. Forest net primary productivity is representative of carbon sink in vegetation which retains the amount of carbon based on aboveground biomass.The main purpose of this study is to suggest a method to extract climate-driven changes in the carbon sink of forest ecosystems in order to increase the accuracy of carbon sink reported to the international community. The suggested method is composed of three steps: 1) This study estimated annual forest net primary productivity change due to climate change using the Carnegie-Ames-Stanford Approach (CASA) model. 2) The variability of FPAR and temperature affected by climate change was extracted through the Empirical mode decomposition (EMD) algorithm, which decomposes a time-series signal. Then, this value was applied to the CASA model to estimate the change in the net primary production of forest ecosystems. 3) The forest productivity due to the climate effect was derived by comparing the above two results.This assessment approach is expected to understand the variability of forest carbon sink and to support the decision-making of the greenhouse gas reduction report system by assessing climate-driven changes in forest net primary productivity.
Design of an affordable and highly flexible IoT station for multiple gas concentration monitoring
Authors: Renzi Francesco , Cammillozzi Flavio , Cecchini Giancarlo , Filippi Alessandro , Valentini Riccardo
Published: February 2023

The air quality monitoring is a core topic for European environmental policies and worldwide. At the same time technologies such as electrochemical or NDIR gas sensors became affordable and easy to implement in a customized design. A highly flexible monitoring station has been designed and build in order to obtain a customizable and affordable device. It is composed of two boards, one in charge of connectivity and processing while the other allows to insert up to 11 gas sensors. Such number is achieved through the use of three multiplexers that allow to spare input pins of the processor. Moreover the flexibility at the moment is achieved using sensors with the same form factor but adapters are under development to increase the adaptability of the system, both hardware and software. An Arduino MKR zero runs the application that can be run in three different modes: single measurement, time driven or position driven. The last feature is obtained through an optional on-board U-blox GNSS module that allows to georeference the performed measurements. This mode is mainly used when the measurement cell is applied on moving object, such as drones. The system is able to send the data collected and receive commands using MQTT protocol (HiveMQ broker) through a NB-IoT connection and interact with the user from an online dashboard created using Thingsboard. The use of the MQTT protocol allows to send the data to multiple endpoints if the data should be provided also to third parties. Moreover, the data and some parameters are also saved on a sd card. All the system is built on stand alone boards to achieve easy maintaince of the system and to allow a rapid change in the used technology (a plug and play LoRaWan module is under development). Being a multi-application platform, price of the device is of course highly dependent on the chosen set of sensors thus, in the end, on the application itself (i.e. Air pollution or gas emission in barns). To sum up, the device described is a possible solution for an affordable gas concentration measurement system that can be adapted to fit a large variety of use cases combining software and hardware solutions.
Testing a hyperspectral, bio-optical approach for identification of phytoplankton groups in the Chesapeake Bay
Authors: McKibben Morgaine , Schollaert Uz Stephanie , Palacios Sherry
Published: February 2023

The multi- to hyperspectral evolution of satellite ocean color sensors is advancing space-based coastal ocean science and applications. Among anticipated new capabilities is satellite-based identification of phytoplankton groups. In this work the bio-optical Phytoplankton Detection with Optics (PHYDOTax) approach for deriving taxonomic class-level phytoplankton community composition (PCC, e.g. diatoms, dinoflagellates) from hyperspectral information (<= 10 nm spectral resolution) is evaluated in the Chesapeake Bay on the East Coast of the United States. PHYDOTax is among relatively few regionally customizable, optical PCC differentiation approaches available for optically complex water, but these features have not been tested beyond the California coastal regime where it was initially developed. Study goals include: 1) regional parameterization to an enclosed estuary, including novel addition of colored dissolved organic matter (CDOM) and non algal particles (NAP) to the algorithm, and 2) performance assessment using field-based remote sensing reflectance and pigment data from two cruise campaigns. Algorithm testing was conducted at spectral resolution settings relevant to hyperspectral sensors (e.g. 1nm, 5nm, 10nm) and with and without incorporation of CDOM and NAP. Statistical performance was typically robust for cryptophyte and cyanophyte phytoplankton groups with variable to poor results for dinoflagellate and diatom groups. Small, but significant, differences were observed in algorithm output at varied spectral resolutions, but no significant differences were observed in runs with or without CDOM and NAP. Based on these datasets, PHYDOTax is able to differentiate some phytoplankton groups in an estuary. The approach warrants further investigation with in estuaries and other optically complex regimes.
ACTRIS - CiGas side-by-side interlaboratory comparison of new and classical techniques for formaldehyde measurement in the nmol/mol range
Authors: Salameh Therese , Tison Emmanuel , Stratigou Evdokia , Dusanter Sébastien , Gaudion Vincent , Jamar Marina , Tillmann Ralf , Rohrer Franz , Winter Benjamin , Verea Teresa , Muñoz Amalia , Bachelier Fanny , Daele Véronique , Grandjean Audrey
Published: February 2023

Formaldehyde is an important hazardous air pollutant, classified as carcinogenic to humans by the International Agency for Research on Cancer (IARC). It is emitted directly by many anthropogenic and natural sources, and formed as a secondary product from volatile organic compounds (VOCs) photo-oxidation. Formaldehyde is, as well, a significant source of radicals in the atmosphere resulting in ozone and secondary organic aerosols formation. Routine measurements of formaldehyde in regulatory networks within Europe (EMEP) and USA (EPA Compendium Method TO 11A) rely on sampling with DNPH (2,4-Dinitrophenylhydrazine)- impregnated silica cartridges, followed by analysis with HPLC (High-performance liquid chromatography).
In the framework of the EURAMET-EMPIR project « MetClimVOC » (Metrology for climate relevant volatile organic compounds: http://www.metclimvoc.eu/), the European ACTRIS (Aerosol, Cloud and Trace Gases Research InfraStructure: https://www.actris.eu/) Topical Centre for Reactive Trace Gases in-situ Measurements (CiGas), IMT Nord Europe unit – France, organized a side-by-side intercomparison campaign in Douai-France, dedicated to formaldehyde measurement in a low amount fraction range of 2 - 20 nmol/mol, from 30 May to 8 June 2022. The objectives of the intercomparison are to evaluate the instruments metrological performance under the same challenging conditions, and to build best practices and instrumental knowledge.
Here, we present the results from the intercomparison, where ten instruments belonging to seven different techniques were challenged with the same formaldehyde gas mixture generated either from a cylinder or from a permeation system, in different conditions (amount fractions, relative humidity, interference, blanks, etc.), flowing through a high-flow (up to 50 L/min) Silcosteel-coated manifold. The advantages/drawbacks of the techniques will be discussed.
Subsurface preferential flow occurrence and relevance in agricultural hillslopes: experimental evidence
Authors: Filipović Vilim , Ehrhardt Annelie , Gerke Horst H.
Published: February 2023

Preferential flow (PF) has long been discussed as potential cause for unintended contamination of ground and surface waters with agrochemicals. In agricultural soil landscapes, especially along hillslopes, the mostly vertically-directed preferential flow (VPF) of infiltrating water in unsaturated topsoil horizons fosters the formation of water saturated pore regions at less permeable subsoil horizons that can trigger laterally-oriented preferential flow (LPF) along subsurface preferred flow paths. The occurrence of LPF processes depends on complex interrelations between soil properties and subsurface structures, climatic conditions, crop development, and agro-management, among other factors. Field observations in hillslope agricultural soil landscapes to quantify the relevance of LPF are rare. Here we present studies on LSF processes at two contrasting sites. One is the CarboZALF-D, located in northeastern Germany in hummocky arable soil landscape (Luvisol and Regosol soil types). The second (SUPREHILL) is an agricultural vineyard hillslope with Stagnosol soils located in central Croatia. Both sites show erosion and tillage effects in the soils along slopes. An extensive network of soil moisture sensors, suction cups, and lysimeters are installed at both sites. Relevant soil physical, hydraulic, and chemical properties have been determined for running simulation models. The SUPREHILL site has been equipped also with self-constructed subsurface runoff collection system, while at CarboZALF-D site, LPF was captured by a field tracer experiment; and in the laboratory, LSF along a soil horizon boundary was studied on undisturbed soil monoliths. Different subsurface flow processes were identified and captured at the two sites, for SUPREHILL shortly below the topsoil along the lower permeable Btg horizon and for CarboZALF-D at buried topsoil under colluvium and along coarser-textured bands within compact glacial till C-horizon. The collected experimental results revealed the qualitative importance of LPF and transport in the subsurface; the presented experimental data will be used for the model-based quantitative analysis of the LPF related processes.
Local dust plume analysis and classification using ground-based remote sensing and microphysical measurement acquired at Lhù’ààn Mân’ (Kluane Lake), Yukon
Authors: Sayedain Seyedali , O’Neill Norman T. , King James , Hayes Patrick L. , Bellamy Daniel , Washington Richard , Engelstaedter Sebastian , Vicente-Luis Andy , Bachelder Jill , Bernhard Malo
Published: February 2023

The sub-Arctic Lhù’ààn Mân’ (Kluane Lake) region in the Canadian Yukon is subject to regular drainage wind-induced dust plumes emanating from the Slims River basin. This dust emissions site is just one of many current and potential future proglacial dust sources in the Canadian North. We employed ground-based passive and active remote sensing (RS) techniques to analyze the complementarity and redundancy of such RS retrievals relative to springtime (May 2019) Kluane Lake microphysical measurements. This included correlation analyses between ground-based coarse mode (CM) aerosol optical depth (AOD) retrievals from AERONET AOD spectra, CM AODs derived from co-located Doppler lidar profiles and OPS (Optical Particle Sizer) surface measurements of CM particle-volume concentration ( ). An automated dust classification scheme tied to intercorrelations between lidar-derived CM AOD, AERONET-derived CM AODs and  variations was developed to objectively identify local dust events. Lidar ratios derived from a priori refractive indices and OPS-derived effective radius statistics were also validated using AERONET-derived CM AODs. Bi-modal CM PSDs from AERONET inversions showed CM peaks at ~ 1.3 µm and 5 – 6.6 µm radius: we argued that this was associated with springtime Asian dust and Lhù’ààn Mân’ dust, respectively. Correlations between the CIMEL-derived fine-mode (FM) AOD and FM OPS-derived particle-volume concentration suggest that remote sensing techniques can be employed to monitor FM dust (which is arguably a better indicator of the long-distance transport of HLD).
Diagnosing multi-hazard risk research, practice, and policy in a European context - lessons learnt from the first year of research in MYRIAD-EU
Authors: Ciurean Roxana Liliana , Duncan Melanie , Gill Joel , Smale Lara , Crummy Julia , Stuparu Dana , Schlumberger Julius
Published: February 2023

The first priority of the Sendai Framework for Disaster Risk Reduction is Understanding Disaster Risk. To achieve this goal, it is essential that research and practice draw upon previous disaster risk work. What can the use of terminology and concepts tell us about the barriers and opportunities to further our understanding of disaster risks? How can we build more effectively upon existing tools, methods, and approaches to inform future multi-hazard risk solutions? And what is the current multi-risk governance landscape in Europe? To answer these questions, we present the results of the first work package (WP1) of MYRIAD-EU – a multi-disciplinary, multi-sector project on systemic risk assessment and management in the E.U., funded by the Horizon 2020 Programme. WP1 aimed at undertaking a common baseline development to ensure that all MYRIAD-EU work packages are underpinned by a common understanding of terminology, concepts, and current academic, policy, and industry perspectives on multi-hazard, multi-risk assessment and management.In this presentation, we briefly introduce the methods, outputs, and outcomes of the first year of Diagnosis research in MYRIAD-EU. We look closer at two outputs, namely the Handbook of multi-hazard, multi-risk definitions and concepts, and the Disaster Risk Gateway wiki platform, aimed at promoting interdisciplinary research and engagement between different actors involved in disaster risk assessment and management. Finally, we reflect on lessons learnt and highlight upcoming work in this project.
Urban textures and flood hazard impacts from 2008 to 2018 in Nairobi, Kenya
Authors: Majani Bernard , Malamud Bruce D , Millington James
Published: February 2023

This research develops a methodology to examine the change over time of urban textures for Nairobi in relation to flood hazard impact on infrastructure. We use three Landsat 7 (30 m resolution) images of Nairobi (2008, 2013, 2018). ‘Urban textures’ are the spatial distribution, shape and relative arrangement of urban elements such as green spaces, trees, roads and height of buildings and their geometry in a given urban city. Here, revising Stewart and Oke’s classifications for built-up areas and land cover types, we classify each of the three Landsat images into 14 urban textures using maximum likelihood under supervised classification. The building structure types were then examined using local knowledge, YouTube videos, Google Street View and ground truthing. We find that from 2008 to 2018 the urban textures with the largest total increases in area were compact mid-rise by 49.9km2 (6.9%) and compact high-rise by 11.3 km2 (1.5%). In contrast, the compact low-rise residential urban texture decreased greatly (29.2 km2). This suggests that for non-industrial land uses, Nairobi has grown upward. Accuracy assessments for the 2008 [2018] map were 83.6% [87.9%] with 95% confidence interval of 75.4–90.0% [80.6–93.2%] and kappa statistic 0.777 [0.834]. We then examine the spatial temporal change of intensive (high severity – low frequency) and extensive (low severity – high frequency) flood hazard events in terms of pattern, trend and impact in relation to rainfall, elevation, and urban textures. We find that urban textures for 2018 have reduced area coverage of the urban texture lightweight low-rise, having partly changed to compact midrise. The impact of change in land use through the development of urban areas greatly affects flooding and impacts in terms of severity. Flooding is more prevalent close to the major rivers in Nairobi, some of which occur in the non-informal settlements. Flood water flows from the higher areas of Ngong and Kikuyu towards the town centre, Nairobi west into industrial area going towards east lands. Rivers in Nairobi regularly overflow their banks and inundate low-lying areas like T-Mall, Nairobi west, industrial area and Mathare valley. These are the flood hotspots of Nairobi that also have high severity of fatalities and impact on infrastructure. We believe that our methodology of examining urban textures over time, using remote sensing images, combined with flood hazard impact information, will help scientists and hazard managers better understand, and prepare for, the interlinked nature of urban change with the flood hazard.