bluuebunny/crossref_metadata_2025 huggingface dataset:
eWaterCycle V2: enabling Hydrology as a Service (HaaS) 
Authors: Kalverla Peter , Schilperoort Bart , Verhoeven Stefan , Drost Niels , Hut Rolf
Published: March 2024

2024 marks the 10th anniversary of presenting eWaterCycle at EGU [i]. Over the past decade, we've been building a platform capable of running global hydrological simulations, that democratizes research, and fosters reproducibility [ii]. We've built various libraries, added models, and glued them together. Our efforts culminated in the release of eWaterCycle V1 in 2021[iii].  

For eWaterCycle V1 we initially targeted users of hydrological models, enabling researchers and students to do experiments that they would not have been able to do before. While this narrow focus was great for designing the core functionality of the platform, the process for adding or upgrading supported models was still tedious. Model developers had to make changes to the core of eWaterCycle whenever they updated their model.  

To address this, we have recently released a new version of the eWaterCycle Python package that connects all components of the platform. In V2, compatibility with existing models is facilitated through a plugin structure. In contrast to eWaterCycle V1, plugins are small, simple, and self-contained, and can easily be maintained by the model owners. This structure also facilitates gradual adoption of standards until the compatibility layer becomes obsolete.

Another improvement in eWaterCycle V2 is that it is now possible to run certain BMI models without containers. The use without containers, on the other hand, enables new use cases for purposes like education. While we recognize that this facilitates the development process, we still emphasize the use of containers for sharing and reproducibility.

The changes in V2 make eWaterCycle simpler and more robust and facilitate a better governance structure for developing and maintaining the platform and contributed models, enabling what we envision for “Hydrology as a Service”: infrastructure providers host instances of the eWaterCycle platform, model developers can register their model to make it available on these platforms, and researchers can access and use them. 

[i] https://ui.adsabs.harvard.edu/abs/2014EGUGA..16.6291V [ii] https://doi.org/10.1002/2017WR020665 [iii] https://doi.org/10.5194/gmd-15-5371-2022 
Scots pine response to short-term dry conditions after long-term soil moisture manipulation experiment  
Authors: R. Freund Elham , Villiger Maurus , M. Lehmann Marco , Hu Zhaoyong , Meusburger Katrin , Gessler Arthur
Published: March 2024

Transpiration fluxes from land to the atmosphere hinge significantly on the degree to which trees opt to open their stomata to trade off water for CO2. Yet, the terrestrial ecosystem response to the changes in the atmosphere (CO2, VPD, etc.) and the redistribution of water on land in an era of change are largely unknown. In addition, the effects of such long-term changes in trees’ adaptation strategies and resilience under short-term dry conditions are not yet fully understood. To address this issue we determined stable water isotopologues within a long-term (20-year) irrigation experiment in a drought-prone Scots pine-dominated forest in one of the driest areas of Switzerland, Pfynwald. Our sampling included plots with trees growing under naturally dry conditions (control), irrigated (from 2003 to present), and previously irrigated (irrigation stop; irrigated from 2003–2013; control condition since 2014). We have installed an in-situ high-frequency isotope measurement system in the field to sample stable water isotopologues (2H and 18O) in different soil depths, tree xylem, and in the atmosphere and to track tree water uptake dynamics at the control, irrigated, and irrigation stop plots. The sampling was complimented with manual extraction of soil and xylem water samples at the three treatment plots for isotope analysis in the lab. Our preliminary findings support the hypothesis that pine forests adjust their carbon allocation strategies during long-term wet periods, establishing a deeper rooting system to access deeper water sources. This adaptive mechanism enhances their resilience during short-term dry periods.
Multiphysical description of atmospheric pressure interface chemical ionization in MION2 & Eisele type inlets
Authors: Finkenzeller Henning , Mikkilä Jyri , Juuti Paxton , Righi Cecilia , Sarnela Nina , Kangasluoma Juha
Published: March 2024

The inlets of chemical ionisation mass spectrometers are fundamental instrument components in chemical ionisation mass spectrometry (CIMS). However, the sample gas and reagent ion trajectories are often understood only in a general and qualitative manner. Here we evaluate two common atmospheric pressure chemical ionisation inlets (MION2 and Eisele type inlet) with 3D physico-chemical models regarding the reagent ion and sample gas trajectories and evaluate their efficiencies of reagent ion production, reagent ion delivery from the ion source volume into the ion-molecule mixing region, and the interaction between reagent ions and target molecules. The models are validated by laboratory measurements and quantitatively reproduce observed sensitivities to tuning parameters, including ion currents and changes in mass spectra. The study elucidates how the different transport and chemical processes proceed within the studied inlets, how space charge is already relevant at concentrations of as low as 107 cm-3, and compares the two investigated models. The models provide insights into how to operate the inlets and will help in the development of future inlets that further enhance the capability of CIMS.
Baltic Sea reanalysis from Copernicus Marine Service – soaked in local knowledge
Authors: Ringgaard Ida Margrethe
Published: March 2024

A regional reanalysis is like a good local restaurant: it builds on local knowledge and focus is on local specialities. For the Baltic Sea, one of the most important local ‘specialities’, or features, is the gateway: the narrow and shallow Danish Straits where the salty North Sea water mass meets with the fresh Baltic Sea water. If this very important process of inflow of saline and oxygen-rich water from the North Sea into the Baltic Sea is not modelled correctly, the results will be of insufficient quality, and not represent the ocean accurately. Currently, global ocean models cannot run with sufficiently high resolution, nor do they focus on local features required to simulate the Baltic Sea adequately. This requires a regional ocean model. Here we present the CMEMS high-resolution ocean reanalysis for the Baltic Sea covering the 30 year period 1993 to 2023. The reanalysis consists of the physical state as well as the bio-geo-chemical state and the waves. Preliminary results from 2 on-going tasks will also be presented: 1) extending the reanalysis back in time to 1980 and 2) expanding the data assimilation from the present parameters (SST and in-situ temperature and salinity profiles) to include sea ice concentration, nutrients and oxygen.
Coastal and regional marine heatwaves and cold spells in the northeastern Atlantic
Authors: Simon Amelie , Poppeschi Coline , Plecha Sandra , Charria Guillaume , Russo Ana
Published: March 2024

The latest Intergovernmental Panel on Climate Change (IPCC) report describes an increase in the number and intensity of marine heatwaves (MHWs) and a decrease in marine cold spells (MCSs) in the global ocean. How- ever, these reported changes are not uniform on a regional to local basis, and it remains unknown if coastal areas fol- low the open-ocean trends. Surface ocean temperature mea- surements collected by satellites (from 1982–2022) and 13 coastal buoys (from 1990–2022) are analyzed in the north- eastern Atlantic and three subregions: the English Channel, Bay of Brest and Bay of Biscay. The activity metric, com- bining the number of events, intensity, duration and spatial extent, is used to evaluate the magnitude of these extreme events. The results from in situ and satellite datasets for each of the studied regions are quite in agreement, although the satellite dataset underestimates the amplitude of activity for both MHWs and MCSs. This supports the applicability of the method to both in situ and satellite data, albeit with cau- tion on the amplitude of these events. Also, this localized study in European coastal northeastern Atlantic water high- lights that similar changes are being seen in coastal and open oceans regarding extreme events of temperature, with MHWs being more frequent and longer and extending over larger ar- eas, while the opposite is seen for MCSs. These trends can be explained by changes in both the mean of and variance in sea-surface temperature. In addition, the pace of evolu- tion and dynamics of marine extreme events differ among the subregions. Among the three studied subregions, the English Channel is the region experiencing the strongest increase in summer MHW activity over the last 4 decades. Summer MHWs were very active in the English Channel in 2022 due to long events, in the Bay of Biscay in 2018 due to intense events and in the Bay of Brest in 2017 due to a high occur- rence of events. Winter MCSs were the largest in 1987 and 1986 due to long and intense events in the English Channel. Finally, our findings suggest that at an interannual timescale, the positive North Atlantic Oscillation favors the generation of strong summer MHWs in the northeastern Atlantic, while low-pressure conditions over northern Europe and a high off the Iberian Peninsula in winter dominate for MCSs. A pre- liminary analysis of air–sea heat fluxes suggests that, in this region, reduced cloud coverage is a key parameter for the generation of summer MHWs, while strong winds and in- creased cloud coverage are important for the generation of winter MCSs.
Fire trends on ATTO footprint over the last two decades
Authors: Dajti Gisela , Urquiza David , van Asperen Hella , Jones Sam , Komiya Shujiro , Lavric Jost , Hantson Stijn , Botía Santiago
Published: March 2024

The Amazon Tall Tower Observatory is located in the central Amazon (S 02 08.9°, W 059 00.2°) inside the Uatumã Sustainable Development Reserve and has been monitoring continuously the atmospheric composition since 2013. The site is set up with two measurement towers of 80 meters and a tall tower of 325 meters for continuous monitoring of trace gases and aerosols. The surface influence (hereafter footprint) of the research station covers a large area to the east and northeast with the fetch extending for hundreds of kilometres, overlapping with the main branch of the Amazon River reaching the city of Belém (during the dry season) and large swaths of primary forest over the Amapá state (during the wet season).  We have analysed trends in fire counts (using MODIS thermal anomalies) and burned area (GFED4 and GFED5, Global Fire Emission Database 4th and 5th version) over the last two decades (2000-2023) inside the ATTO footprint and found that both show increasing and significant trends for the months of June (14,68 fire counts/year) July (42,23 fire counts/year), August (59,6 fire counts/year) and September (148,6 fire counts/year). Spatially, fires are located on easternmost part of the footprint and there is no evidence of a spatial trend approaching ATTO. Interestingly, in October the mean longitude of the fire counts over the period of interest shows a trend migrating from -56°W to -54°W, but with no significant trend in fire counts. We complement these results by analysing mole fractions of carbon monoxide (a proxy for biomass burning) at ATTO for an overlapping period (2013-2023). In addition, we provide links to the environmental drivers explaining these trends and spatial patterns. Observing biogenic greenhouse gases enhances our understanding of the Amazonian rainforest’s carbon budget, influenced by climatic conditions, land use alteration and other anthropogenic impacts.  
Development of extended medium-range reforecasting system based on the Korean Integrated Model (KIM)
Authors: Kim Shin-Woo , Shim Taehyoun , Hong Ja-Young , Park Hye-Jin
Published: March 2024

The Korean Integrated Model (KIM) is a global numerical weather prediction (NWP) system developed by the first phase project of the Korea Institute of Atmospheric Prediction Systems (KIAPS) and has been used as the operational NWP system at the Korea Meteorological Administration (KMA) since April 2020. The second phase project of KIAPS aims at developing a next-generation NWP system to seamlessly predict from very short-range to extended medium-range. To improve the extended medium-range forecast, one of the main goals of KIAPS is to develop the ensemble prediction system with coupling to land, ocean, and sea ice. The production of extended medium-range reforecast data is necessary to understand the climatological characteristics and model biases of KIM. KIAPS developed an initial version of reforecasting system based on the KIM atmopheric model. The system has a spatial resolution of 50 km (NE090NP3) and consists of 91 vertical layers. We produce reforecast of the cold season cases for 20 years (from 2001 to 2020) and perform the diagnosis and verification of reforecast data. A suite of sensitivity experiments are also performed to investigate the impact of initial perturbations on the ensemble prediction system.
Knowledge curation and review of water resources studies in Lebanon 
Authors: Merheb Mohammad , Cudennec Christophe , Moussa Roger
Published: March 2024

Knowledge fragmentation poses a significant obstacle to the effective implementation of the science-policy-practice (SPP) nexus in water resources management. While this fragmentation can arise from the inherent specialization in scientific studies, external factors such as compartmentalized thinking in management and policymaking, along with competition among stakeholders, including researchers, can further compound the issue.
This study focuses on mitigating knowledge fragmentation in Lebanon's water resources, a country where civil wars, geopolitical conflicts, confessionalism, and corruption have intensified compartmentalization. The objective is to create the most comprehensive database of water resources studies conducted in Lebanon since its establishment in 1920. The database with aroud 400 entries encompasses both peer-reviewed and gray literature documents, covering various water resources domains such as water balance, quality, management, and governance. It falls within the WMO plan of actions for hydrology (2023-2030) especially ambitions F, G, and H. Aiming at providing a solid base for operational hydrology through a more complete knowledge of Lebanon’s water resources. One that can help reach the sustainable development goals especially goal 6. Utilizing this database, we assess the current knowledge base, review existing water-related knowledge, and identify gaps in knowledge production, policies, and operationalization.
The studies are categorized into four main topics: water balance, water quality, water management, and water governance, each with relevant sub-topics. A bibliometric analysis is conducted, and the content is summarized and discussed, revealing critical findings and challenges. Finally, as we acknwoledge the need to complete and continually update this database, we sure hope that this work will contribute to overcoming the barrier of knowledge fragmentation in the SPP nexus and will serve as a valuable tool for researchers, policymakers and stakeholders to better operationalize Lebanon’s water resources management.
Parameter estimation and sensitivity in Lagrangian oil spill models
Authors: Skancke Jørgen , Nepstad Raymond
Published: March 2024

Lagrangian oil spill models, like many environmental models, are constructed from a large set of submodels, each with their own set of parameters and constants. The submodels belong to different domains of science, such as physical oceanography, petroleum chemistry, sediment and coastal geoscience, biochemistry, and ecotoxicology. Generally, these submodels have been derived and fitted to observations independently and within separate contexts, before being combined in some sequence to become the oil spill model. In this way, oil spill models have a large set of input parameters and constants that affect model output. When oil spill models are compared with observed data, it is challenging to know which of this large set of parameters should be adjusted to improve the model's performance against observations. Given the scale of oil spill models, parameters from different submodels can be correlated in non-trivial ways. It is also generally not known to which parameters the oil spill model displays the most sensitivity. This is further complicated by parameter sensitivity being dependent on environmental input such as wind speeds and ocean currents. Here, we present a sensitivity analysis of an idealised oil spill model, with submodels for oil surface spreading, entrainment of oil by breaking waves, resurfacing of oil, emulsification of surface oil by water uptake, and increase in viscosity of oil due because of weathering and water uptake. We discuss our results in context of improving oil spill models from observations, both laboratory data and sea-truth in the form of past spill events. 
Earth Observation-Driven Flood Response for Emilia-Romagna: The SaferPlaces Platform
Authors: Mazzoli Paolo , Luzzi Valerio , Renzi Marco , Bargiotti Marianne , Outmani Sabrina , Pasetti Stefania , Bagli Stefano , Renzi Francesca
Published: March 2024

In May 2023, the region of Emilia-Romagna, Italy, experienced an unprecedented hydrological event when 350 million cubic meters of rain fell over 36 hours, leading to widespread flooding and landslides. This disaster, affecting 100 municipalities, was compounded by antecedent drought conditions that had decreased the soil's water absorption capacity. Earth observation (EO) data became critical, providing emergency services with the means to assess and manage the catastrophe and facilitate post-event damage evaluation.The SaferPlaces platform, supported by the ESA InCubed programme, played a pivotal role in disaster response. It provided the Civil Protection of Emilia-Romagna with high-resolution flood water and depth maps, crucial for decision-making in the aftermath of the floods. This cloud-based platform integrates satellite data, climatic records, and AI algorithms to generate global flood forecasts.Leveraging AI, SaferPlaces processed terrain data alongside inundated area information, combining in situ measurements with satellite data from Copernicus Sentinel-2, CosmoSky-Med, Planet, and SPOT. This was further enriched with local data from municipalities and the Emilia-Romagna Civil Protection, enhancing urban flood area accuracy.Detailed maps illustrating flood extent in the severely hit municipalities of Faenza, Cesena, Forlì, and Conselice were generated. These contained vital data on water depth and volume, forming the basis for a preliminary Flood Damage Assessment. These assessments were crucial for authorities to estimate economic losses swiftly.The suite of tailored algorithms within SaferPlaces, extracts flood water masks from satellite imagery. This module, accessible on-demand through a user-friendly interface, requires few parameters from users to accurately delineate flooded areas and contribute to the Global Flood Monitoring system.The main workflow of algorithm includes the GFM procedure for baseline flood extent retrieval, the Hydraflood method for flood mask extraction via GEE, and the CommSNAP pipeline for processing commercial data. The final output is a flood mask for the area and event of interest, which can also feed into the GFI model to identify flood-prone areas.This study underscores the essential role of integrated EO and AI technologies in managing hydrological disasters. The SaferPlaces platform's capacity to synthesize multi-source data and provide actionable intelligence marks a milestone in the power of interdisciplinary approaches in enhancing disaster resilience and preparedness.
Exploration of Solar Wind Phenomena: Database and Duration Analysis
Authors: Asenovski Simeon , Georgieva Katya , Kirov Boian
Published: March 2024

The provided open-access database compiles information on various solar wind types and their durations in near-Earth space, encompassing high-speed solar wind streams, coronal mass ejections, and slow solar wind. The categorization of these different flows relies on criteria derived from experimental data on the primary solar wind parameters. Employing physical conditions, the database precisely delineates the commencement and conclusion of each solar wind event. Its primary objective is to span the last five 11-year solar cycles (cycles 20 to 24) and partially 25, leveraging in situ satellite observations. The study also explores the temporal dynamics of high-speed solar wind streams (HSS) and endeavors to establish their precise duration.
A mesoscale model for aerosol-cloud interaction studies WRF-PMCAMx-UF with insights to secondary ice production
Authors: Holopainen Eemeli , Georgakaki Paraskevi , Patoulias David , Sotiropoulou Georgia , Foskinis Romanos , Pandis Spyros , Nenes Athanasios
Published: March 2024

The interaction between aerosols and clouds is a complex process and it causes large uncertainties in predicting the global climate. This interaction has been studied using chemical transport models (CTMs) as they simulate the distribution and composition of atmospheric aerosols. In this study, we developed a coupled version of the Weather Research and Forecasting (WRF) model with the PMCAMx-UF CTM (Skamarock et al., 2008; Patoulias et al. 2022). We did this by using prognostic cloud droplet number in the Morrison et al. 2009 cloud microphysics scheme of the WRF model. We calculated the prognostic cloud droplet number from the predicted aerosol fields of PMCAMx-UF using the Morales and Nenes 2014 activation scheme. In addition, we investigated the effects of prognostic cloud droplets to secondary ice production (SIP) in the WRF model. This involved the incorporation of various SIP processes, including Hallett-Mossop (HM), collisional fracturing and breakup (BR), droplet freezing and shattering (DS), and sublimational breakup of snow (SBS) and graupel (SBG), following the approaches outlined in Georgakaki et al. 2023. First we evaluated the impact of coupled WRF-PMCAMx-UF model with prognostic droplets to the same model with prescribed droplet number as well as the SEVIRI satellite observations. Secondly we evaluated the effects of adding SIP processes and prognostic droplets to non-SIP and prescribed droplet case and satellite observations. The results showed that using the combined model with prognostic droplets decreased the cloud droplet number concentration (CDNC) and liquid water content (LWC) when compared to the prescribed droplet simulation. This caused a more positive surface radiative forcing and thus a warming effect. In addition, the number of small particles decreased and large particle numbers increased when switching to prognostic droplets. Further, comparing to satellite observations, the prognostic droplet simulation performed better in terms of CDNC than the prescribed droplet simulation. Adding the SIP processes to the model increased the ice crystal number concentration (ICNC) as well as LWC in some areas. Compared to satellite observations, introducing SIP and prognostic droplets into the model performed slightly better in terms of CDNC as well as ice water path (IWP) than the non-SIP and prescribed droplet cases. Thus, a more realistic representation of CDNC as well as incorporation of SIP processes in the coupled model allows a more precise capture of evolving aerosol-cloud interactions in the atmosphere.
Probabilistic Approach toward Seismic Exploration with Autonomous Robotic Swarms
Authors: Nierula Kai , Shutin Dmitriy , Shin Ban-Sok , Igel Heiner , Keil Sabrina , Bernauer Felix , Reiss Philipp , Sesko Rok , Lindner Fabian
Published: March 2024

This research introduces a novel approach to seismic exploration on the Moon and Mars, employing autonomous robotic swarms equipped with seismic sensing and processing hardware. By relying on probabilistic inference methods, we aim to survey large surface areas to both autonomously identify and map subsurface features such as lava tubes and ice deposits. These are crucial for future human habitats and potential in-situ resource utilization.This endeavor presents unique challenges due to the communication limitations and uncertainties inherent in remote, autonomous operations. To address these challenges, we adopt a distributed approach with robotic swarms, where each rover processes seismic data and shares the results with other rovers in its vicinity, contending with imperfect communication links. Thus, the swarm is used as a distributed computing network. The decisions made within the network are based on probabilistic modeling of the underlying seismic inference problem. A key innovation in this respect is the use of factor graphs to integrate uncertainties and manage inter-rover communications. This framework enables each rover to generate a localized subsurface map and autonomously decide on strategic changes in the seismic network topology, either exploring new areas or repositioning to enhance measurement accuracy of targeted underground regions.The vision is to implement this approach on a distributed factor graph, allowing for a coordinated, probabilistic analysis of seismic data across the swarm. This strategy represents a significant departure from traditional static seismic sensor arrays, offering a dynamic and adaptable solution for planetary exploration. The first step towards realizing this vision involves implementing a Kalman filter for the one-dimensional linear heterogeneous wave equation. This has been achieved by reformulating finite difference schemes for wave propagation simulation into a state-space description. The resulting linear continuous n-th order system can be explicitly solved and rewritten into a discrete state space model that can be used in the standard Kalman filter recursion. However, the standard Kalman filter is limited due to its assumption that both model and process noise are Gaussian. With factor graphs, this limitation can be overcome, enabling a more robust and versatile analysis. Several simulation results will be shown to demonstrate the performance of these approaches.We intend to extend the approach to higher-dimensional problems, implementing distributed versions of the Kalman filter and factor graph with simulated, non-perfect communication links. Eventually, the seismic inverse problems will be solved in these frameworks. Successfully achieving these objectives could greatly enhance our capabilities in extraterrestrial exploration, paving the way for more informed and efficient future space missions.
Dissolved Organic Matter from Coastal Vegetated Ecosystems Through the Lens of Carbon Sequestration
Authors: Baiko Dariya , Dittmar Thorsten , Böning Philipp , Seidel Michael
Published: March 2024

Coastal vegetated ecosystems (CVEs) are highly productive habitats whose role in coastal biogeochemical cycles cannot be understated. The high productivity of salt marshes, seagrass meadows, and mangrove forests is channeled into the sediments and into the sea in form of particulate and dissolved organic matter (DOM). While labile DOM is degraded within a short time frame, recalcitrant DOM compounds can remain in the oceanic water column for hundreds to thousands of years. However, so far, DOM has received little consideration in carbon sequestration approaches. In sulfidic porewater of CVEs, DOM can undergo abiotic sulfurization, producing dissolved organic sulfur (DOS), which may render it resistant to biodegradation. Thus, the formation of DOS in CVEs can act as a link between labile and recalcitrant pools of DOM and provide the means of carbon transport across and beyond ecosystem boundaries. We analyzed DOM as well as inorganic nutrients in samples from temperate (German) and tropical (Malaysian) mesotidal CVEs. Unprecedentedly high porewater DOC concentrations were found in both temperate salt marshes as well as in tropical mangroves. High proportions of DOS in the DOM pool demonstrated accumulation of sulfurized compounds in the porewater. Molecular DOM patterns deduced from ultrahigh-resolution mass spectrometry (FT-ICR-MS) analysis indicated that up to 50% of the several thousand molecular formulas identified were characteristic of the analyzed CVEs. Adjacent habitats shared a substantial proportion of DOM molecular formulas indicating lateral transfer of organic material. This emphasizes that the potential for carbon dioxide removal of CVEs extends beyond the areas with above-ground biomass.
Creating tools for the generation of weather-based crop calendars to support climate services. 
Authors: Aguilar Enric , Boqué Anna , Olano Jon , Gascon Tania , Gray Sebastian , Agniga Kossi
Published: March 2024

The UN 2030 Sustainable Development Agenda included achieving Zero Hunger as one of its prominent goals. According to Food and Agriculture Organization for the United Nations (FAO), this objective is far from being achieved, as over 735 million people faced hunger in. The geographical distribution of food insecurity is not even across the globe, with greater impact over less developed countries where subsistence agriculture is a major livelihood. Weather, climate, climate variability and climate change alter in time and space the phenological stages of crops and, therefore, agricultural planning and production. One of the most widely used tools to convey weather and climate information to final agricultural users are weather-based crop calendars. They use time series of daily accumulated rainfall to provide actionable information on the timing of phenological stages, specifically on the times for planting (start of the season) and harvesting (end of the season) for different crops and different agroclimatic zones. The creation of a Crop Calendar requires quality controlled and homogeneous rainfall series to detect the onset and cessation of the rainy season, plus crop-specific information, like drought resilience and crop cycle length. Rainy season onset and cessation are determined using threshold-based methods, which combine rainfall accumulation over several days and additional criteria to avoid false alarms, such as the presence/absence of consecutive dry days. The rainy season onset and cessation for each year are calculated and their timeseries fit to a probability distribution to evaluate the climatological expectations for early/normal/late onsets and cessations. The final crop calendar results from assimilating the first/early/normal/late onsets of the rainy season to the span of possibilities for the sowing dates. The harvest dates are defined as the sowing dates plus the crop cycle length for each variety and agroecological zone. In this contribution, we present a series of tools developed with the support of the World Meteorological Organization (WMO) and the Climate Risk and Early Warning Systems Initiative (CREWS) project in West Africa and the Enhancing Adaptive Capacity of Andean Communities through Climate Services (ENANDES) project in South America, following a “from data to service” approach and including a series of training events. The process is illustrated using rainfall series from Togo.
Numerical modelling of antigorite dehydration at 3 GPa: reaction-induced stress variations and effects of tectonic forcing
Authors: Porkoláb Kristóf , Moulas Evangelos , Schmalholz Stefan
Published: March 2024

Dehydration reactions at high pressures are considered as sources of stress perturbations potentially leading to the nucleation of intermediate-depth earthquakes. Dehydration reactions entail the release of water and significant solid volume changes, while solid deformation, fluid flow, and the migration of the reaction front interact with each other. Observation-based quantification of such complex interactions is challenging; hence, the exact mechanisms of dehydration-induced seismicity remain unclear. One of the most prominent dehydration reactions in subducted slabs, that may contribute to intermediate-depth seismicity, is the breakdown of antigorite at high pressures. To improve the understanding of this process, we quantify interactions between the metamorphic reaction, solid deformation, and fluid flow for the phase transformation of antigorite --> enstatite + forsterite + water. We present a two-phase, hydro-mechanical-chemical model that is based on the coupled solution of rock deformation, Darcy-flow of pore fluids, and equilibrium thermodynamics of the dehydration reaction (assuming isothermal conditions). We consider total and non-volatile mass conservation, while solid and fluid densities are based on thermodynamic lookup tables. We investigate the magnitude of reaction-induced stresses and test the effects of kinematic boundary conditions and rheological heterogeneities via a broad parameter study. We relate our findings to natural examples of antigorite dehydration and discuss implications for dehydration-induced earthquakes.AcknowledgementsThe reported investigation was financially supported by the National Research, Development and Innovation Fund, Hungary (PD143377).
Microseismic monitoring and insights of rupture mechanism from China's pilot EGS project in Gonghe, Northwestern China
Authors: Zhang Hao ,   Hao Zhang, Institute of Geomechanics, Chinese Academy of Geological Sciences
Published: March 2024

Enhanced Geothermal Systems (EGS) are effective means of developing hot dry rock (HDR) type geothermal resources, transforming low porosity and permeability rock masses deep underground into artificial geothermal reservoirs with high permeability through reservoir stimulation. EGS systems can economically extract a considerable amount of thermal energy over the medium to long term to be utilized for power generation. The development and research of EGS has been ongoing internationally for over 40 years. However, at present, the development of EGS is still in the stage of on-site experimental research and development, and its commercial development still faces many challenges. China, like many other countries, is in need of developing deep geothermal resources to meet its energy demands. In 2017, a well named GR1 with a temperature of 236°C was drilled to a depth of 3705m in the Gonghe Basin of Qinghai Province. Recognizing the potential of HDR resources, the China Geological Survey launched an exploration and production project in Gonghe Basin in 2019. Following several critical technological breakthroughs, the first power generation test of HDR was successfully conducted in the Gonghe Basin in 2022. This study offers a detailed introduction to the localization of microseismic events that occurred during thermal reservoir stimulation at different stages of development. By analyzing these microseismic events, we can evaluate the effectiveness and volume scale of artificial thermal reservoir transformation. In addition, we assess the development of natural fractures utilizing data from 3D seismic attributes of the granite, imaging logging, etc. We conclude by discussing implications for successful geothermal development of the specific geological conditions present at the Gonghe HDR field, based on the localization results of microseismic data and the distribution of natural fractures in the field.
Urban trees phenology and local climate feedbacks of a residential area in Berlin.
Authors: Tsirantonakis Dimitris , Looschelders Dana , Fenner Daniel , Meier Fred , Chrysoulakis Nektarios , Christen Andreas , Grimmond Sue , Birkmann Joern
Published: March 2024

The role of vegetation in urban climate has been in the spotlight in recent years, as it can play significant roles in carbon sequestration through photosynthesis as well as in the urban energy balance, mainly through evapotranspiration and shading. Based on these, the green infrastructureof cities is considered as a potential solution to lower the urban net CO2 exchange and lower air temperatures, improving the resilience of cities in the context of climate change.Being part of the general physiological responses of trees, the abovementioned mechanismshave been excessively studied in natural environments. However, the quantification of the different effects of these processes in complex and heterogeneous urban landscapes is challenging. In this study, we demonstrate initial results of a year-long observation period of tree vegetation in a residential area in Berlin, Germany, using PhenoCam and flux-tower observations. The phenology curves were extracted from half-hourly PhenoCam images of trees from the Acer, Aesculus, Fagus, and Pinus genera and analysed in combination with comprehensive observations of  thesurface energy balance components, including net radiation, turbulent sensible and latent heat fluxes as well as CO2 fluxes and standard meteorological variables. We showcase the agreement between the gradual development of tree foliage fordeciduous vegetation (which dominates the area) with: a) the upward latent heat flux seasonal maxima observations; and b) the decline of upward CO2 flux values. In particular, the timing of the start of season (SOS), peak of season (POS) and end of season (EOS) is assessed and compared to changes detected in the flux trends. Our data indicates a strong connection of the green-up period of deciduous vegetation with the largest rate of decrease of the CO2 fluxes, leading to a change from CO2 source to sink for a constrained time period. These observations highlight the measurable effect of vegetation-related carbon sequestration that can take place in urban areas with significant vegetation cover under specific/average meteorological conditions.
The spatio-temporal variability of particulate pollution through modelling: new insigths from a dense network of micro-sensors in urban environment
Authors: Marion Sarah , Martiny Nadège , Dudek Julita , Boilleaut Mathieu , Ristori Marie , Detournay Anaïs
Published: March 2024

Current high-resolution models generally present a relatively flat signal that poorly represents the spatial and temporal variability of particulate pollution at the scale of a city. This study is based on the SIRANE model, an urban air quality model that enables to simulate the dispersion of atmospheric pollutants according to the city geometry at a 10-meter spatial resolution. The model outputs provided by the ATMO Bourgogne - Franche - Comté air quality monitoring agency are actually post-processed based on a physical equation defined for the PM10 (d < 10 μm) and PM2.5 (d < 2.5 μm) pollutants and based on mass concentration levels measured by 4 micro-sensors deployed in representative sites in Dijon for the year 2021.This study first aims at verifying if the equations established could be applied to another period, taking into account any differences in atmospheric circulation. The second objective is to test if the integration of more measurement stations enables to significantly refine the physical equations and improve the SIRANE maps correction. More generally, we would like to evaluate to what extent micro-sensors can improve the information provided by high-resolution models and when with respect to the particle season.The work is conducted in three steps: first, apply the physical equations to 2022 and 2023 SIRANE maps and compare the outputs with reference stations; second, analyse measurements from the micro-sensors implemented in Dijon in Summer 2023; third, use this dataset to select new representative traffic, background and intermediate sites in order to refine the physical equations and quantify the added value.The first results are encouraging as the SIRANE corrected maps based on the first 4 representative micro-stations in Dijon enable a more realistic spatial variability in the city, illustrated by a clear pollution gradient from the city centre to the suburbs (with a greater range between concentration levels and a higher number of classes), and a less flat season cycle with more realistic PM levels in Winter everywhere in the city.
Implementing a new model of urban solid waste management at a local scale: application to the municipality of l'alcora (castellón, spain)
Authors: Pérez Estela , Rodrigo-Ilarri Javier , Rodrigo-Clavero Maria-Elena
Published: March 2024

The implementation of efficient municipal waste management systems is crucial to address current environmental challenges. These systems allow for the minimization of waste generation, promotion of reuse and recycling, and proper management of remaining waste. By reducing the amount of waste sent to landfills, soil, water, and air pollution decreases, and the emission of greenhouse gases is limited. Moreover, efficient municipal waste management fosters the circular economy by recovering valuable resources from waste, thereby contributing to the conservation of raw materials and long-term sustainability.This work presents a methodology for urban waste management tailored to medium-sized municipalities (approximately 10,000 inhabitants). It highlights the resources and tools available at the municipal level to achieve the objectives set by European Directives on waste management. These resources encompass environmental communication and information, economic, fiscal, and regulatory instruments, as well as a proposal for a model of urban solid waste collection.The proposed methodology is applied to the municipality of l'Alcora (Castellón, Spain), whose current management model relies on anonymous municipal waste collection, where citizens voluntarily decide where to dispose of their waste based on their environmental awareness, without any form of reward or penalty for their actions. This voluntariness and limited promotion of environmental awareness have led to a general lack of interest among the population in waste management. This situation has, in general, caused Spain to lag behind other EU member states in achieving the goals of waste prevention, valorization, and recycling set by the European Union.
Exploring aerosol size distributions from polar to tropical zones of the Atlantic Ocean
Authors: S Raj Subha , Hrabe de Angelis Isabella , Basic Sanja , M. Aardema Hedy , A. Slagter Hans , Weber Jens , Ll. Calleja Maria , Krüger Matteo , O. Andreae Meinrat , Dragoneas Antonis , Nillius Björn , Walter David , Berkemeier Thomas , H. Haug Gerald , Pöschl Ulrich , Schiebel Ralf , Pöhlker Christopher
Published: March 2024

Aerosols over the oceans significantly influence the composition of the Earth’s atmosphere and climate. Over the vast expanse of oceans, aerosols are emitted at high rates, primarily through wave breaking and bubble bursting. Additionally, secondary aerosol particles can be formed by gas-phase reactions. Particles emitted from shipping activities, long-range transport from continents, and potential downward transport from the upper troposphere can also contribute to aerosols in the marine boundary layer (MBL). Hence, marine aerosols represent a highly heterogeneous and complex mixture pivotal in regulating the global radiation budget.This study explores aerosol number size distributions over the North Atlantic Ocean measured on the research vessel S/Y Eugen Seibold. The cruises conducted between June 2020 and September 2021 covered a broad geographic range from polar (~67° N) to tropical (~3° N) waters. Aerosols were sampled at approximately 13 m above the ocean surface using two sets of instrumentation covering particle sizes of 10 nm to 430 nm and 520 nm to 20 µm.Three aerosol size modes, Aitken, accumulation, and coarse, were consistently identified throughout the dataset, aligning with prior research. Additionally, we observed an intermittently occurring nucleation mode and a bimodal coarse mode. While the presence of a nucleation mode suggests aerosol formation over the open ocean, it did not exhibit the typical banana-shaped contour plots usually observed during new particle formation and subsequent growth. Prior research indicates that ships may act as emitters in this size range, in addition to secondary formation from atmospheric gases.Here, we describe and discuss particle number size distributions observed over the open ocean, raising questions about the formation and lifecycle of aerosol modes. Our goal is to track the behavior of nucleation, Aitken, accumulation and coarse modes in the MBL with high temporal resolution, spanning the latitudinal range of the northern Atlantic Ocean. A comprehensive dataset is prepared by incorporating surface ocean data retrieved on board and satellite observations to disentangle the natural and/or anthropogenic origins of aerosols responsible for the observed particle number size distributions in the MBL.
North Atlantic teleconnection reflected in a Mid-Holocene Ecuadorian speleothem
Authors: Vargas Danny , Palcsu László , Temovski Marjan
Published: March 2024

Paleoclimate reconstructions in northern tropical South America are scarce and hindered due to the small temperature fluctuations. In particular, the potential of records to study past climate variability close to the Equator (0° 0’ 0”) and at the periphery of the Amazon basin has been unexplored. The reason obeys to the complex orography of the Andes and the direct influence of the Intertropical Convergence Zone (ITCZ) and the South American Monsoon features (i.e., low level jets) which overlap at the so called “monsoon trough” and masks a clear annual seasonality.In this contribution, we present a newly constructed speleothem record (Dino-1) from Central Ecuador based on 14 U-Th Ages from 6849±51 to 5469±62 yr (Mid-Holocene) for studying the evolution of the hydrology during centennial to millennial scales. For the calibration of the archive, we undertook a 4-year monthly monitoring of stable isotopes in precipitation (δ2H and δ18O) and temperature in the vicinity and inside the cave.Results show that the rainfall lowest δ18O values occur during austral autumn (AMJ) and spring (ON), while higher values are found in summer (DJFM) and winter (JAS), displaying a strong negative correlation with the bimodal rainfall pattern. Lagrangian back trajectory analysis (2015-2022) indicates that moisture is seasonally advected from the Tropical North and South Atlantic. At centennial scale, the Dino-1 δ18O time series seems to capture the variability of Bond event 4 (abrupt cold ice-raft inputs from the North Atlantic), coherent with other paleoarchives (e.g., speleothems, lacustrine sediments, ice cores) in the same timeframe. On the other hand, at millennial scale, our record (although short) is in line with previous studies indicating that the ITCZ has been the main system modulating the climatology in Northern South America driven by the increment in the solar forcing input.