bluuebunny/crossref_metadata_2025 huggingface dataset:
Manufacturing surprise: How information content, modeling capabilities and decision making purpose influence optimal streamflow monitoring
Authors: Weijs Steven , Werenka Alexander , Kovacek Daniel
Published: February 2023

Streamflow monitoring is a key input to water resource management, as it is an important source of information for understanding hydrological processes and prediction catchment behaviour and resulting flows. Both the monitored and the predicted flows support important decisions in areas such as infrastructure design, flood forecasting and resource allocation. It is therefore essential that the predictive information we have about our water resources serves these various needs.Since observations are from the past and our decisions affect the future, models are needed to extrapolate measurements in time. Similarly, streamflow is not always measured at places where the information is needed, so interpolation or extrapolation is needed in space or across catchment properties and climates. Recent advances in publicly available large datasets of streamflow records and corresponding catchment characteristics have enabled succesful applications of machine learning to this prediction problem, leading to increased predictability in ungauged basins.Since information content is related to surprise, we could see the objective of monitoring networks as manufacturing surprising data. This is formalized in approaches for monitoring network design based on information theory, where often the information content of the sources, i.e. the existing monitoring stations, has been investigated, including the effects of redundancy due to shared information between stations.In this research, we argue that information content is related to unpredictability, but is inevitably filtered through several layers, which should be considered for monitoring network design. Examples of such filters are the models used for extrapolation to ungauged sites of interest, the target statistics of interest to be predicted, and the decision making purpose of those predictions. This means that the optimal monitoring strategy (where to measure, with how much precision and resolution, and for how long) depend on evolving modeling capabilities and representation of societal needs. Also, biases in the current neworks may exist as a function of how they are funded.In this presentation, these theoretical aspects are investigated with examples from an ongoing project to investigate the streamflow monitoring network in British Columbia, Canada, which recently experienced record-breaking floods. 
Seasonal hydro-sedimentary dynamics of a small tropical estuary under Amazone influence (the Cayenne river estuary, French Guiana)
Authors: Sottolichio Aldo , Roche Nicolas , Gardel Antoine , Maury Tanguy , Brunier Guillaume , Lesourd Sandric
Published: February 2023

The Cayenne River estuary is a small mesotidal tropical estuary located in the French Guiana (04° 54’ N / 52° 21’ W). It forms at the confluence between the Cayenne and Montsinery rivers, and is one of the numerous estuarine systems situated between the mouths of the Amazon and the Orinoco Rivers, likely to be controlled by coastal mud banks formed by suspended sediment discharge of the Amazon river. This estuary drains a small coastal catchment composed of mangrove forests. Dynamics of this estuary are described for the first time from oceanographic and sedimentary data collected in 2022 during dry and rainy seasons. Surveys consisted of 13h anchor stations at three locations distributed across the main channel, at 5 km from the mouth, where vertical profiles of salinity and turbidity were measured every 30 mn. Complementary vessel-towed ADCP transects were performed in order to capture the current field and residual flow in the same cross section. The data collection was performed during one semidiurnal tidal cycle at neap and spring tides. Water levels records indicate that frictional forces dominate, since the tidal range decreases from the mouth toward the upper estuary, although the tidal wave propagates up to 30 km usptream from the mouth, with increasing asymmetry between ebb and flood. Current patterns show that flood current dominates near the left bank and the ebb current is more intense in the center and the right bank. Residual flow shows inflow at west and inflow at east boundaries, except for neaps in dry season, when a two-layer estuarine circulation develops on the central channel. During the dry season, tidal currents induce strong resuspension of fine sediments. A very turbid estuary is found in the dry season, suggesting pumping of mud from the coastal area. Less loaded waters in the wet season result from the predominance of the fluvial dominance which flushes the suspended matter to the ocean. Residual fluxes of suspended sediment were calculated at each of the three anchor stations. Residual flux follows trends of residual currents, meaning that they are all directed downstream in the wet season, with the exception of the left bank of the estuary, while in dry season they are upstream oriented near the bottom and downward oriented near the surface. These first observations confirm the influence of coastal mud in the infilling of the estuary. However they need to be completed to get a reference state of the estuary, as it is soon about to experience significant anthropogenic changes related with an increasing development of port activities.
Moho Inversion of East China Sea and Its Adjacent Areas Based on Potential Field Data
Authors: Wang Dingding , Wang Wanyin , Zhang Yimi
Published: February 2023

East China Sea and its adjacent areas are an important part of the circum-Pacific tectonic belt, and its fluctuation characteristics of Moho can provide an important basis for the study of the deep structure of the western Pacific. At present, the inversion of Moho depth based on potential field data is an important task. Meanwhile, its inversion accuracy is closely related to the gravity anomaly data quality, and to the density contrasts and inversion algorithm. We use the fast solution algorithm of forward problem for gravity field in a dual interface model to eliminate the gravity influence of terrain and sediments, and adopt the minimum curvature potential field separation method to remove the effect of residual geological bodies. Then we try to identify the Moho gravity anomaly as the regional field which has the strongest correlation with depths estimations from seismic data. Regression analysis and the "3σ" principle are used to delete the constraint points of Moho depth with large deviations, and the Bouguer plate formula is used to estimate the laterally variable density contrasts of Moho. Finally, the Moho depth in East China Sea and its adjacent areas is obtained by the dual-interface fast inversion algorithm, and the inversion deviations are mostly concentrated within 2 km. The inversion result shows that there is an obvious local uplift zone of Moho in East China Sea Basin, while the Okinawa Trough basin is located on a whole Moho uplift. The strike of the two uplift belts has the same change from NE to NNE.
Investigation of thermal cooling potential of Permeable Paving at an urban trial site in London, UK
Authors: Butler Adrian , Rowan Thomas , Paschalis Athanasios
Published: February 2023

The built environment is being forced to adapt to rising global temperatures and severe weather events such as more intense storms, longer heatwaves etc. The proliferation of impermeable surfaces has over time led to many urban design problems, such as storm surges overwhelming sewers. Increasing urban temperatures are also caused by the built environment, the Urban Heat Island (UHI) effect. These impacts can be tackled through better infrastructure. Permeable paving offers an alternative to many impermeable surfaces, providing a robust surface with the advantage of drainage. Its ability to mitigate heat, however, remains poorly understood.To address this, a detailed performance evaluation of two permeable paving pads, one a control and the other actively (mains supply) and passively (rainwater retention) watered, was undertaken. The 16 m2 permeable paving pads were installed at Imperial College London’s White City campus (London, UK) and monitored over 4 months (July to October 2021). The pads were bounded by a raised impermeable barrier and consisted of a block layer with foundations of grit underneath. Both pads were placed on a slope enabling them to be drained, a weir prevented flooding and a tap allowed for complete drainage. The pads were instrumented with internal heat and water content sensors, as well as surface thermal sensing, and a dedicated weather station. Several artificial wetting events were conducted during the summer of 2021 alongside controlled laboratory work. A significant cooling effect was found (average of 1, and up to 5 of cooling), which was around half that computed for well-watered green space. It was found that the evaporation rate of the wetted pad was dependent on the degree of saturation, with the greatest heat loss efficiency occurring when the grit layer was partially saturated. A variety of secondary observations were also made, including issues around water fouling, and porous bricks. Whilst permeable paving can assist with flood alleviation, is it hoped, through minor design modifications, that it can also help tackle extreme urban heat impacts.
Spatial-temporal transferability assessment of remote sensing data models for mapping agricultural land use
Authors: Wijesingha Jayan , Dzene Ilze , Wachendorf Michael
Published: February 2023

To assess the impact of anthropogenic and natural causes on land use and land use cover change, mapping of spatial and temporal changes is increasingly applied. Due to the availability of satellite image archives, remote sensing (RS) data-based machine learning models are in particular suitable for mapping and analysing land use and land cover changes. Most often, models trained with current RS data are employed to estimate past land cover and land use using available RS data with the assumption that the trained model predicts past data values similar to the accuracy of present data. However, machine learning models trained on RS data from particular locations and times may not be well transferred to new locations and time datasets due to various reasons. This study aims to assess the spatial-temporal transferability of the RS data models in the context of agricultural land use mapping. The study was designed to map agricultural land use (5 classes: maize, grasslands, summer crops, winter crops, and mixed crops) in two regions in Germany (North Hesse and Weser Ems) between the years 2010 and 2018 using Landsat archive data (i.e., Landsat 5, 7, and 8). Three model transferability scenarios were evaluated, a) temporal - S1, b) spatial - S2 and c) spatial-temporal - S3. Two machine learning models (random forest - RF and Convolution Neural Network - CNN) were trained. For each transferability scenario, class-level F1 and macro F1 values were compared between the reference and targeted transferability systems. Moreover, to explain the results of transferability scenarios, transferability results were further explored using dissimilarity index and area of applicability (AOA) concepts. The average macro F1 value of the trained model for the reference scenario (no transferability) was 0.75. For assessed transferability scenarios, the average macro F1 values were 0.70, 0.65 and 0.60, for S1, S2, and S3 respectively. It shows that, when predicting data from different spatial-temporal contexts, the model performance is decreasing. In contrast, the average proportion of the data inside the AOA did not show a clear pattern for different scenarios. In the context of RS data-related model building, spatial-temporal transferability is essential because of the limited availability of the labelled data. Thus, the results from this case study provide an understanding of how model performance changes when the model is transferred to new settings with data from different temporal and spatial domains.
Water level and stable Isotope based river aquifer interaction in different river styles of a semi-arid river
Authors: Duggad Yash , Jain Vikrant , Padhya Virendra , Deshpande Rajendra
Published: February 2023

Understanding the groundwater-surface water (GW-SW) interaction is critical for river management, especially in water-stressed regions such as semi-arid and arid areas. The pattern of GW-SW interaction may vary across variable valley settings, floodplain width and river planform.
This study aims to analyse the pattern of GW-SW interaction in different River Styles reaches. The study is carried out in the Sabarmati River basin in using stable isotopes. Sabarmati River is an intermittent River of 419 km in length that drains a 21,085 km2 area in the semi-arid region of Western India. Representative sites of each River Styles were selected for water level measurement and stable isotope samples. The study was conducted in the post-monsoon period of 2021-22, which represents groundwater contribution to river system after major runoff seasons. Samples at each River Styles reach were collected along a cross-section. 1 river water and up to 4 groundwater samples (2 from each bank) were collected along the transect. A total of 48 samples were collected along 11 such transects. The depth of groundwater and stage of river water at each sample site was also measured.
 
The GW depth and river stage data indicate GW-SW connection for 9 sites (all except 1 are from the upstream region), while was inconclusive for 2 (all in the middle and lower reaches). Stable isotope-based analysis suggests a similar scenario. The upper reaches, which are gaining, have enriched δO18 composition and lower d-excess than the groundwater. The depleted isotopic composition of groundwater indicates faster groundwater recharge from the meteoric water. Such reaches are characterized by boulders and gravel beds. The reach-scale variability of the river from the losing-gaining stream also collaborates with the reach-scale variation of δO18 isotopic values. The losing reach has a depleted δO18 isotopic composition than the groundwater, thus indicating recharge of groundwater from the river water and the impact of evaporation. The integration of the River Styles map and GW interaction study suggests the following – (a) Generally, River Styles that were showing connected and gaining reaches were found to have low sinuosity  (b) River Styles with occasional and discontinuous flood-plains showed an inconclusive result about river aquifer connectivity by both methods (c) For all confined or partly unconfined reaches with bedrock margin-controlled settings, a connected river aquifer system was noted. The study highlights geomorphic control on the important process of GW-SW interaction in a semi-arid river channel.  
Keywords: River style, stable isotope, river-aquifer interaction
Monitoring of suspended mater with H-ADCP devices and comparison with sedimentation rates and soil properties in the Köhlfleethafen harbour basin of the Hamburg port
Authors: Ohle Nino , Shaikh Suleman , Thies Thomas , Strotmann Thomas , Schmekel Ulrich
Published: February 2023

For future strategies in water depth maintenance in the Port of Hamburg, determining the navigability limit (i.e. the nautical safe depth) is of major importance. For this purpose, a project "Nautical Depth" was set up at the Hamburg Port Authority (HPA), which is dedicated to dealing with this issue. The aim is to measure a nautical safe depth under various boundary conditions and to identify limits for a safe passage of high concentrated soil suspensions. Among other things within the project monitoring data of suspended sediment fluxes and data from multibeam echo-sounders and sub-bottom profilers were analysed and compared.Therefore, the backscatter along the cross-section of a long-term H-ADCP monitoring station was analysed and calibrated with water samples and data of optical backscatter sensors. The standard monitoring frequency of the data is 1 minute. The data were aggregated and summarized as half-tide values and flood-tide, ebb-tide and the residual sediment fluxes were calculated. These data sets were compared with hydroacoustic measurements of the bathymetry, including sub-bottom profilers, in the harbour basin Köhlfleethafen nearby the cross-section of the H-ADCP monitoring station. In a defined and shaped area volumetric calculations, layer densities and the amount of sedimented dry matter of the bottom layer were analysed.The presentation will give a closer look to the sampling, monitoring and interpretation of the data. The data sets of sediment fluxes derived by the H-ADCP will be compared with the data sets of the hydroacoustic measurements. The influence of dredging campaigns will be shown, and an interpretation of the data will be given. The investigations also show, that the soil properties and analysed data sets are dependent from local and regional boundary conditions, as flow velocity, grain size distribution and especially in Hamburg from the organic matters and nutrients within the suspended and the soil material. All data sets are used to optimize the maintenance strategies of the nautical bottom in the Köhlfleethafen area, especial regarding sediment conditions methods with bed levellers or water injection dredgers.References:Nino Ohle, Thomas Thies, Rolf Lüschow, and Ulrich Schmekel - Sediment sampling and soil properties of sediments in the Hamburg port and the river Elbe in comparison with hydro-acoustic measurements , Proceedings of the EGU2020-16468, https://doi.org/10.5194/egusphere-egu2020-16468Ahmad Shakeel, Claire Chassagne, Jasper Bornholdt, Nino Ohle, and Alex Kirichek - From fundamentals to implementation of yield stress for nautical bottom: Case study of the Port of Hamburg, Ocean Engineering, Volume 266, Part 2, 2022, 112772, ISSN 0029-8018, https://doi.org/10.1016/j.oceaneng.2022.112772
Assessing the predictability of droughts through seasonal forecasts
Authors: Dal Monte Thomas , Cherchi Annalisa , Alessandri Andrea , Gaetani Marco
Published: February 2023

Atmospheric circulations at the mid-latitudes are marked by circulation regimes, structures evolving in space very slowly and persisting over time. Their persistence and duration in a context such as Europe's, could lead to weather patterns, such as heat waves and drought, that have a­­ major impact on many socio-economic sectors. Forecasts at seasonal timescale are becoming then crucial to plan or give relevant indicators for societal applications. Predictability of such events could be of great use in further applications related to energy and management of water supplies. Also, this may provide useful insights to understanding the increase in frequency and intensity of these extreme events and their location.The late purpose of this study is to investigate the predictability of European droughts in a forecast range of 1-3 months. To this aim, drought events are firstly identified, and state-of-the-art seasonal forecast products are analysed to compute the skill for targeted drought-related climate variables and/or circulation patterns. Observational datasets, high-resolution reanalysis and latest generation satellite observations will be used for the characterization of drought events and the forecast validation.
Analysis of diffuse scattering from liquid and amorphous samples: protocols and software
Authors: Boccato Silvia , Morard Guillaume , Garino Yiuri , Sanloup Chrystele , Zhao Bin , Morand Marc , Antonangeli Daniele
Published: February 2023

Fostered by third-generation synchrotron sources, experimental studies of physical and chemical properties of liquids at high pressure and temperatures are constantly pushed towards more and more extreme conditions, with applications ranging from Earth and planetary science, to material science, to fundamental physics.In the last 20 years, many efforts have been dedicated to the development of a method to obtain structural information from the X-ray diffuse scattering signal of a liquid [1], allowing, for instance, to improve our understanding of the structure and evolution of deep planetary interiors. However, while data collection protocols are by now quite advanced and overall comparable across beamlines worldwide, data analysis largely differs depending on user and employed codes. To answer to the need of a unified data analysis tool for liquids and amorphous systems, we developed Amorpheus [2].Amorpheus is an open-source, versatile, free and easy-to-use software for the analysis of X-ray diffuse scattering signal, allowing to perform a customizable analysis of a large amount of data and to invert for the density.  Available on GitHub [3] it is fully accessible by the community. This software has been tested on data collected with DAC and with large volume presses and it is well adapted for the analysis of liquid metals and alloys, as well as of amorphous systems. Here we will present and discuss selected examples of data analysis performed by Amorpheus in order to determine local structure and density of liquid iron binary and ternary alloys at planetary core conditions.[1] Eggert JH, Weck G, Loubeyre P, Mezouar M. Quantitative structure factor and density measurements of high-pressure fluids in diamond anvil cells by x-ray diffraction: Argon and water. Phys Rev B. 2002;65(17):174105. doi:10.1103/PhysRevB.65.174105[2] Boccato S, Garino Y, Morard G, et al. Amorpheus: a Python-based software for the treatment of X-ray scattering data of amorphous and liquid systems. High Press Res. 2022;42(1):69-93. doi:10.1080/08957959.2022.2032032[3] https://github.com/CelluleProjet/Amorpheus
The Jurassic oceanic tectonostratigraphy of the high-pressure Lanzo Valleys Ophiolites (Western Alps)
Authors: De Togni Marcello , Gattiglio Marco , Balestro Gianni
Published: February 2023

The Western Alpine Ophiolites represent the remnants of the oceanic lithosphere of the Alpine Tethys (Ligurian–Piedmont Ocean), which separated the Europe and Adria plates at the Jurassic time. These ophiolites now consist of several tectonic units (i.e., the Piedmont Zone) exposed in the axial sector of the Alpine orogenic belt (Balestro et al., 2019). Along the inner Western Alps, the meta-ophiolites are characterized by subduction-related eclogite-facies metamorphic peak conditions (i.e., the Internal Piedmont Zone) and underwent polyphase deformation. Despite this Alpine overprint, records of the oceanic tectonostratigraphy are partly preserved.The Lanzo Valleys meta-Ophiolites (LVO) are tectonically juxtaposed with continental basement units (Dora-Maira to the South and Gran Paradiso to the North), resulting in an extended but poorly known ophiolitic complex. In the southern sector of the LVO (i.e., the Viù Valley), new geological mapping, structural analysis and lithostratigraphic observations, allowed us to reconstruct the oceanic tectonostratigraphy of this Alpine Tethys segment (De Togni et al., 2021). The LVO succession consists of serpentinite, metagabbro, metabasalt and metasediments, whose primary lithostratigraphic relationships highlight different phases of the oceanic tectonostratigraphy. Mantle peridotites were firstly intruded by small gabbroic plutons, mainly of Mg-Al-rich composition, followed by minor Fe-Ti-rich differentiated types. Mantle rocks were then exhumed at the seafloor, and partly overlain by laterally discontinuous metabasaltic lavas. The latters were interlayered with mafic breccia and sandstone layers and with calcschist (i.e., the syn-extensional succession). The whole succession was then sealed by quartzite, impure marble and calcschist, representing the post-extensional succession.The reconstructed oceanic tectonostratigraphy of LVO highlights, as documented in other sectors of the Western Alpine Ophiolites, the original occurrence of tectonically unstable reliefs and structural lows, linked to spreading-related extensional tectonics at the Jurassic time.  ReferencesBalestro G., Festa A. & Dilek Y. 2019. Structural architecture of the Western Alpine ophiolites, and the Jurassic seafloor spreading tectonics of the Alpine Tethys. J. Geol. Soc. Lond., 176, 913–930.De Togni M., Gattiglio M., Ghignone S. & Festa A. 2021. Pre-Alpine tectonostratigraphic reconstruction of the Jurassic Tethys in the high-pressure Internal Piedmont Zone (Stura di Viù Valley, Western Alps). Minerals, 11 (4), 361.
Drinking water temperature model for urban environments validated with measurements from real-life distribution networks
Authors: van Summeren Joost , Moerman Andreas , Blokker Mirjam , Quan Pan
Published: February 2023

The Dutch drinking water sector distributes treated drinking water without a disinfecting residual. Among many other microbiological safety measures, Dutch water utilities are legally obliged to distribute drinking water to the customers’ tap at a maximum temperature of 25 °C. Ongoing urbanization, climate change, and subsurface infrastructure intensification related to the energy transition pose a growing risk to meet this requirement.Previous research at KWR has shown that the temperature of drinking water converges to the temperature of the surrounding soil that, in turn, is influenced by weather conditions and the presence of anthropogenic heat sources, such as electric power distribution stations and district heating pipes. During a hot summer, cool drinking water reaches the soil temperature within hours. The rate of warming up depends on hydraulic conditions, dimensional and thermal properties, and a delaying effect caused by the continuous supply of drinking water that cools down the surrounding soil.KWR has developed numerical tools to predict the temperature of distributed drinking water in the presence of subsurface heat sources and fluctuating weather conditions. These tools can be used to assess the impact of climate change and the urban environment on drinking water temperatures and investigate the optimized design of distribution networks and the urban environment.Our contribution describes the validation of the numerical model using drinking water temperatures measured in a real-life Dutch DWDS. The case study concerns Ø300 mm pipes in the city of Leeuwarden (Vitens drinking water company). We discuss the results in the context of two additional case studies that compare model predictions and temperature measurements in a Ø100 mm drinking water distribution network and a Ø160 mm single pipe. Finally, we discuss future applications that can improve codes of practice regarding the organization of subsurface infrastructure; a central point of attention is the installation of drinking water and district heating pipes at safe distances.
Assessing the spatio-temporal changes of groundwater parameters: a multivariate geostatistical approach
Authors: Palma Monica , Maggio Sabrina , Cappello Claudia , Congedi Antonella , De Iaco Sandra
Published: February 2023

Groundwater over-exploitation and environment pollution, together with rising temperatures and other climate changes, can cause a large imbalance in the soil physicochemical properties, with a negative impact on economic, social and human health conditions. Therefore, monitoring and assessing the evolution in space and time of groundwater qualitative parameters as well as quantitative status are crucial aspects for a sustainable water management.Multivariate Geostatistics foresees dedicated tools for analyzing multivariate spatio-temporal data which are characterized by heterogeneous patterns in space-time, such as those concerning hydrogeological data. In the literature, few analyses (Jang et al., 2012; Yazdanpanah, 2016; Mastrocicco et al., 2021) have been developed on the main groundwater qualitative indicators through the use of spatio-temporal multivariate geostatistical methodologies.This paper aims to propose a spatio-temporal multivariate analysis for some benchmark indicators describing the qualitative and quantitative status of an unconfined aquifer in Italy. By applying the fitting procedure proposed in De Iaco et al. (2019) and recalled in Cappello et al. (2022), a spatio-temporal multivariate correlation model is developed for forecasting purposes. Then, on the basis of a comparison among predicted values of the variables under study and values recorded for the same variables a decade before, hazard maps of groundwater degradation are produced by through a non-parametric approach, identifying those vulnerability areas where the aquifer system could be contamined. The empirical findings will help the policy makers to pursue effective actions aimed at safeguarding groundwater resources. REFERENCES- Cappello, C., De Iaco, S., Palma, M., 2022. Computational advances for spatio-temporal multivariate environmental models. Comput. Stat. 37, 651–670. https://doi.org/10.1007/s00180-021-01132-0- De Iaco, S., Palma. M., Posa, D., 2019. Choosing suitable linear coregionalization models for spatio-temporal data. Stoch. Environ. Res. and Risk Assess. 33, 1419–1434.- Jang, C.S., Chen, S.K., Kuo, Y.M., 2012. Establishing an irrigation management plan of sustainable groundwater based on spatial variability of water quality and quantity. Journal of Hydrology, 414-415, 201–210- Mastrocicco, M., Gervasio, M.P., Busico, G., Colombani, N., 2021. Natural and anthro- pogenic factors driving groundwater resources salinization for agriculture use in the Campania plains (Southern Italy). Science of the Total Environment, 758, 144033.- Yazdanpanah, N. 2016. Spatiotemporal mapping of groundwater quality for irrigation using geostatistical analysis combined with a linear regression method. Model. Earth Syst. Environ., 2, 1-18.
Dissolved organic carbon (DOC) analyses: vials, sample filtration and acidification, matrix effects and stability
Authors: Tisserand Delphine , Daval Damien , Fernandez-Martinez Alejandro , Nemery Julien , Sarret Geraldine , Spadini Lorenzo , Truche Laurent
Published: February 2023

Despite the presence of an ISO protocol for the determination of dissolved organic carbon (DOC) since 2018, a variety of protocols is used in the literature. The way of sampling and storage is crucial to get reliable results, especially when DOC concentrations are low. This technical note describes experiments first carried out on DOC contribution from several materials: (i) opaque glass vials versus polypropylene (PP) vials, (ii) filter membranes and (iii) acids. The effect of glass vial decontamination, as well as the temperature of storage (4° C versus -18°C) with time were evaluated. The possible matrix effects due to the presence of sulfides (SH2S), sodium (Na) or calcium (Ca) in the samples were tested.Opaque glass vial decontamination during 3 h at 450 °C and filtering ultra-pure water through 0.45 µm hydrophilic polytetrafluoroethylene (PTFE) filters previously rinsed with 20 mL resulted in the lowest DOC deviation from the baseline with a 2.6-factor and the lowest relative standard deviation (RSD) at 5% on nine replicates. Compared to the background signal, the lowest DOC concentration was obtained when the acidification was realized with puriss analytical grade hydrochloric acid (HCl) (4.8-factor, RSD = 5%, N= 5).Storage at 4°C ensured minor DOC changes within one month for a 1 mg L-1 DOC solution (factor of increase less than 1.5) whereas for lower concentrations close to the quantification limit (~ 0.5 mg L-1), DOC concentrations in samples filtrated through 0.45 µm PTFE filters varied up to 29% after one-week storage. Even if freezing might intuitively seem to be a reliable way to fix the chemistry of a sample with time, frozen samples showed drastic increases in DOC concentration after one month of storage, which went up to factor of increase from 10 for a 1 mg L-1 DOC acidified solution to 142 for ultra-pure water only.The presence of sulfides (SH2S) did not induce a significant change in DOC concentration (< 10%) whereas sodium (Na) or calcium (Ca) impacted DOC analyses with underestimations from 53% to 75%.
i-φ-MaLe: a novel AI-phasor based method for a fast and accurate retrieval of multiple Solar-Induced Fluorescence metrics and biophysical parameters
Authors: Scodellaro Riccardo , Cesana Ilaria , D'Alfonso Laura , Bouzin Margaux , Collini Maddalena , Chirico Giuseppe , Colombo Roberto , Miglietta Franco , Celesti Marco , Schuettemeyer Dirk , Cogliati Sergio , Sironi Laura
Published: February 2023

The accurate retrieval of Solar-Induced chlorophyll Fluorescence (SIF) is a pivotal target for Earth Observation since SIF can be easily monitored through optical remote sensing and provides unique information concerning the vegetation health status. Here, we propose i-φ-MaLe (metti il nome per esteso), a novel algorithm, which couples the Fourier analysis with a supervised machine learning-based procedure trained with the atmosphere-canopy radiative transfer (RT) SCOPE model.  i-φ-MaLe is the first method able to simultaneously retrieve, from the vegetation reflectance spectra, the Top Of Canopy SIF spectrum, the SIF spectrum corrected for leaf/canopy reabsorption (i.e. at photosystem level), the quantum efficiency (Fqe) and three canopy-related biophysical parameters (Leaf Area Index - LAI, Chlorophyll content - Cab and APAR) in few milliseconds. Validation procedures, based on the analysis of RT simulations, demonstrated that i-φ-MaLe, in experimental conditions (signal to noise ratio – SNR >= 500), estimates each biophysical parameter and SIF spectrum with a relative root mean square error (RRMSE) lower than 5%. In order to investigate the seasonal and daily dynamics of SIF, LAI, Cab, Fqe and APAR, the method has been also applied to field experimental data collected in the context of the AtmoFLEX and FLEXSense ESA campaigns, both at top-of-canopy (TOC) and tower (~100 meters) levels. Concerning the TOC scenario, the retrieved annual dynamic for SIF spectra has been compared with the results obtained by inversion-based methods, showing a good consistency amongthe different approaches (RRMSE ~ 10%). Moreover, SIF daily and annual dynamics, retrieved by excluding the oxygen spectral bands affected by the atmospheric reabsorption,  have been investigated for  high tower measurements. . In this context, i-φ-MaLe provided  promising results that can integrate and possibly overcome complex and computationally expensive atmospheric compensation techniques actually needed to retrieve fluorescence from oxygen absorptions bands. This study demonstrates a promising potential to exploit ground and tower spectral measurements with advanced processing algorithms, for improving our understanding on the link between canopy structure and physiological functioning of plants. Moreover, i-φ-MaLe can be straightforwardly employed to process reflectance spectra and open new perspectives in fluorescence retrieval at different scales.
A low-dimensional dynamical systems approach to climate ensemble design and interpretation
Authors: de Melo Viríssimo Francisco , Stainforth David
Published: February 2023

Earth System Models (ESMs) are complex, highly nonlinear, multi-component systems described by large number of differential equations. They are used to study the evolution of climate and its dynamics, and to make projection of future climate at both regional and global levels – which underpins climate change impact assessments such as the IPCC report. These projections are subject to several sorts of uncertainty due to high internal variability in the system dynamics, which are usually quantified via ensembles of simulations.Due to their multi component nature of such ESMs, the emerging dynamics also contain different temporal scales, meaning that climate ensembles come in a variety of shapes and sizes. However, our ability to run such ensembles is usually constrained by the computational resources available, as they are very expensive to run. Hence, choices on the ensemble design must be made, which conciliate the computational capability with the sort of information one is looking for.One alternative to gain information is to use low-dimensional climate-like systems, which consists of simplified, coupled versions of atmosphere, ocean, and other components, and hence capture some of the different time scales present in ESMs. This approach allows one to run very large ensembles, and hence to explore all sorts of model uncertainty with only modest computational usage.In this talk, we discuss this approach in detail, and illustrate its applicability with a few results. Particular attention will be given to the issues of micro and macro initial condition uncertainty, and parametric uncertainty – including external, anthropogenic-like forcing. The ability of large ensembles to constrain decadal to centennial projections will be also explored.
The Effect of Climate Change on Global Wildfire Activity
Authors: Lampe Seppe , Burton Chantelle , Burke Eleanor , Chang Jinfeng , Christidis Nikos , Forrest Matthew , Gudmundsson Lukas , Huang Huilin , Hantson Stijn , Ito Akihiko , Kelley Douglas , Kou-Giesbrecht Sian , Lasslop Gitta , Li Fang , Li Wei , Nieradzik Lars , Thiery Wim
Published: February 2023

Recent long and intensive wildfire seasons in many regions have highlighted the urgency to understand the shift in worldwide fire regimes, raising the question if human induced climate change has played a role therein. However, attributing changes in fire to anthropogenic climate change is difficult, since possible signals are confounded by multiple drivers including fire weather, fuel availability and sources of ignition. Therefore, fire indices or individual input variables are often used as proxies. There have been some attempts to model drivers of recent trends in fire, though assessment of overall anthropogenic climate change is still lacking. Recent integration of fire models into ISIMIP now allow us to perform a fire impact attribution analysis using multiple coupled fire-vegetation models. Here, we combine both ISIMIP factual and counterfactual simulations with remote sensed observations to understand how burnt area has changed over the historical period due to a changing climate.
Insights from CO2/SO2 gas molar ratio variations and distribution at Stromboli volcano
Authors: Tamburello Giancarlo , Bitetto Marcello , Delle Donne Dario , Aiuppa Alessandro
Published: February 2023

Gas-sensor-based monitoring stations (aka MultiGAS) near degassing volcanic vents sensibly increased the sampling rate of gas composition measurements. In particular, the CO2/SO2 gas molar ratio was demonstrated to be a good indicator of magma depth thanks to the CO2 and SO2 contrasting solubilities in magma. Numerous high CO2/SO2 gas transients recorded days before an effusive/explosive eruption have been reported in the literature (e.g. Etna, Villarrica, Masaya, Poas). The successful detection of a precursor gas signal in these volcanoes has been favoured by the presence of open or highly permeable closed-conduit (as in the case of Poas) and the instrument’s vicinity to a high-flux degassing vent (high signal/noise ratio). Volcanic gas monitoring in Stromboli represents a particular case. Stromboli is characterised by degassing from multiple vents, which exhibit simultaneous different molar gas ratios during quiescent degassing. The gas emissions during transient strombolian explosions are also different, with higher CO2 contents. Stromboli occasionally exhibits major explosions and paroxysms of greater energy which have often shown a substantial variation of the gas bulk composition weeks before their onset. Finally, the safest sites for a monitoring station in Stromboli are located hundreds of meters from the crater terrace, implying that the detected gas concentrations depend on the wind direction and speed. All these features make the analysis and interpretation of the volcanic CO2/SO2 challenging. This work presents a 2-year-long CO2/SO2 time series recorded at the Stromboli’s summit. We discuss different types of analysis that can be performed to enhance the variations before major and paroxysmal eruptions. We apply an iterative algorithm to estimate the time, number and magnitude of abrupt changes within the CO2/SO2 time series and discuss the origin of such variations. We use an algorithm for finite mixture models on the whole dataset to characterise the source of different gas phases. Finally, we compare the measured CO2 and SO2 concentrations with the wind parameters obtained for the area of Stromboli from the ERA5 reanalysis dataset. Hence, we determine the best conditions for gas ratio measurements and how meteorological conditions may affect the measurements' quality.
Sensitivity of ozone return dates to shared socioeconomic pathway in CMIP6 models
Authors: Keeble James , Hassler Birgit , Schlund Manuel
Published: February 2023

Following the success of the Montreal Protocol, stratospheric ozone is projected to recover over the coming decades as halogenated ozone depleting substances decline. However, future projections of stratospheric ozone recovery are also dependent on assumptions made about the emissions of other gases such as CO2, CH4, and N2O. As a result, the pathway of ozone recovery is sensitive to the choice of future emissions scenario. Here we explore ozone recovery under different Shared Socioeconomic Pathways (SSPs) in 6 CMIP6 models that include interactive chemistry schemes: CESM2-WACCM, CNRM-ESM2-1, GFDL-ESM4, GISS-E2-1-G, MRI-ESM2-0, UKESM1-O-LL. We explore the impact of different SSP scenarios on projections of ozone recovery, the date at which total column ozone returns to historic values, and the healing of the ozone hole. Additionally, we compare global mean return dates with regional return dates and explore the different processes affecting the timing of ozone recovery in these different regions.
Variations of the CO2 fluxes and atmospheric CO2 in multi-model predictions with an interactive carbon cycle
Authors: Li Hongmei , Spring Aaron , Dunkl istvan , Brune Sebastian , Bernardello Raffaele , Bopp Laurent , Merryfield William , Mignot Juliette , Sospedra-Alfonso Reinel , Tourigny Etienne , Watanabe Michio , Ilyina Tatiana
Published: February 2023

Variable fluxes of anthropogenic CO2 emissions into the land and the ocean and the remaining proportion in the atmosphere reflect on the global carbon budget variations and further modulate global climate change. A more accurate reconstruction of the global carbon budget in the past decades and a more reliable prediction of the variations in the next years are crucial for assessing the effectiveness of climate change mitigation policies and supporting global carbon stocktaking and monitoring in compliance with the goals of the Paris Agreement.In this study, we investigate reconstructions and predictions of the CO2 fluxes and atmospheric CO2 growth from ensemble prediction simulations using 5 Earth System Model (ESM) - based decadal prediction systems. These novel prediction systems driven by CO2 emissions with an interactive carbon cycle enable prognostic atmospheric CO2 and represent atmospheric CO2 growth variations in response to the strength of CO2 fluxes into the ocean and the land, which are missing in the conventional concentration-driven decadal prediction systems with prescribed atmospheric CO2 concentration.The reconstructions generated by assimilating physical ocean and atmosphere data products into the prediction systems are able to reproduce the annual mean historical variations of the CO2 fluxes and atmospheric CO2 growth. Multi-model ensemble means best match the assessments of CO2 fluxes and atmospheric CO2 growth rate from the Global Carbon Project with correlations of 0.79, 0.82, and 0.98 for atmospheric CO2 growth rate, air-land CO2 fluxes, and air-sea CO2 fluxes, respectively. The CO2 emission-driven prediction systems with an interactive carbon cycle still maintain the predictive skill of CO2 fluxes and atmospheric CO2 growth as found in conventional concentration-driven prediction systems, i.e., about 2 years for the air-land CO2 fluxes and atmospheric CO2 growth, the air-sea CO2 fluxes have higher skill up to 5 years. The ESM-based prediction systems are capable to reconstruct and predict the variations in the global carbon cycle and hence are powerful tools for supporting carbon budgeting and monitoring, especially in the decarbonization processes. Furthermore, we investigate the contribution of uncertainty in the predictions of CO2 fluxes and atmospheric CO2 growth rate from internal climate variability, different model responses, and emission-forcing reductions to identify the prominent challenge in limiting the skill of CO2 predictions. 
Multiscale Characteristics of West African Summer Monsoon Precipitation Derived from UCadMet Network Observations
Authors: Rodríguez de Fonseca Belen , Durán Montejano Luis , González Cervera Alvaro , Gires Auguste , Fall Cheikh Modou Noreyni , Dieng Abdou Lahat , Gaye Amadou  Thierno , Mohino Elsa
Published: February 2023

Since 2012 a joint Université Cheikh Anta Diop de Dakar and Universidad Complutense de Madrid meteorological observation network (UCadMet) has been in place in the city of Dakar (Senegal). During the last years, the observation and data storage systems have been considerably improved. Last summer of 2022, a laser disdrometer was installed providing  detailed information on the size and speed of precipitation with a time resolution of one minute. Observations from several tipping bucket rain gauges are available also at the same site. Summer 2022 has been anomalously rainy in West Africa, with large precipitation events during the African monsoon season, which seems to be enhanced by a La Niña situation in the Pacific. These events have proven to be particularly suitable for evaluating the performance of the installed observing systems and for drawing some conclusions about the characteristics of monsoon precipitation in this region not only at different time scales, but also across scales (from 1 min to season). Commonly used rain rate together with drop size distribution are used to access information on rainfall microphysics. This analysis allows the design of future lines of action considering climate change, for which large precipitation events are expected to become more frequent.