bluuebunny/crossref_metadata_2025 huggingface dataset:
Long-term trends and radiative impact in vertically resolved stratospheric water vapour from ESA WV_cci data records
Authors: Ye Hao , Hegglin Michaela , Hubert Daan , Lambert Jean-Christopher , Walker Kaley , Sioris Chris , Millan Luis , Manney Gloria , Froidevaux Lucien , Kerridge Brian , Siddans Richard , Wang Ray , Plummer David , Krämer Martina , Rolf Christian , Shine Keith
Published: February 2023

Water vapour in the upper troposphere and stratosphere has a significant impact both on the radiative and chemical properties of the atmosphere.  Reliable water vapour climate data records (CDRs) are essential for use in climate research, to assess vertically resolved trends and associated radiative impacts. Within the ESA Water Vapour Climate Change Initiative (WV_cci), new vertically resolved water vapour CDRs in the stratosphere and UTLS were merged from a range of satellite observations. In this contribution, we provide an overview of these CDRs, highlighting innovations in the merging methodologies and results from a detailed quality assessment. In particular, the long-term trends derived from the new water vapour CDRs are compared to other merged datasets, reanalyses, and simulations from chemistry-climate models, with the ESA WV_cci CDRs deemed to be valuable new datasets for climate studies.  We conclude that, mostly driven by dynamical variability, the derived water vapour trends vary significantly depending on the dataset used, chosen time period and location in the atmosphere. Using an off-line radiative transfer model, we estimate the consequence of these differences on the radiative forcing from water vapour changes in the upper troposphere and stratosphere over the past 30+ years.
Ultra-high resolution (micro-bathymetric mapping and sub-bottom profiling) imaging of an active strike-slip fault, the North Alfeo Fault, offshore Catania, Eastern Sicily (Ionian Sea, Central Mediterranean)
Authors: Giovanni Barreca , Arnaud Gaillot , Frauke Klingelhoefer , Pauline Dupont , Edgar Lenhof , Vincent Coussin , Stèphane Dominguez , Marc-Andrè Gutscher
Published: February 2023

The goal of the ERC funded FOCUS project is to study an active fault offshore Catania using fiber optics, sea-floor geodesy, seismological stations (onshore and OBS on the seafloor) and detailed in-situ observations using an ROV and an AUV. Here, we report on the latter. In October 2020 using the ROV Victor6000 and in January 2022 using the AUV IdefX, we performed micro-bathymetric mapping (at an altitude of 50 m above the seafloor) of a 15-km-long segment of the North Alfeo Fault, covering water depths of about 1600 m to 2300 m. A prominent lozenge-shaped transpressive ridge or “pop-up” type structure is one of the primary features of this portion of the fault zone. It forms a flat-topped plateau culminating at about 1700 m water depth. It is cross-cut by a network of N-S striking faults resembling domino blocks or books in a book-shelf.Sub-bottom profiling (using a chirp system on the AUV IdefX at an altitude of 70 m above the seafloor) crossed the transpressive ridge and imaged the network of narrowly spaced (typically 100 - 200 m spacing) N-S striking faults, which are steeply W dipping normal faults. This suggests the transpressive ridge is currently collapsing. Indeed, the eastern part of the plateau is marked by a small (600 m long from headscarp to toe) submarine landslide. The overall pattern in the northern portion of the mapped area (west of the plateau) is a series of oblique secondary faults, crossing the primary fault at an angle of about 30°. Using a very simple analog model of a thin layer of cohesive granular material above two rigid plates, with a slightly curved fault track, it was possible to produce a primary strike-slip fault directly above the cut between the two plates, and several distinct transpressional ridges (pop-ups) as well as transtensional fissures or gashes. Secondary faults form obliquely to the primary fault and are oriented at about a 30° angle clockwise from the trend of the primary fault. This pattern reproduces the large-scale features observed in the micro-bathymetry from the NW prolongation of the North Alfeo fault. A series of analog experiments using different rheologies in the sediment layer is planned in the future to test the likely detachment (nucleation) depth for the strike-slip fault in the basement. 
The Atmosphere’s Oxidizing Capacity in China: Role and Influence of different photochemical processes
Authors: Dai Jianing , Brasseur Guy , Vrekoussis Mihalis , Zhang Yijuan , Zhang Hongliang
Published: February 2023

With the drastic actions initiated by the Chinese authorities to improve air quality, the level of several secondary pollutants including near-surface ozone still has been increasing significantly between years 2013 and 2020, most notably in the Northern China Plain. Alleviating ozone pollution requires a quantitative understanding of the different processes that contribute to the photochemical formation and destruction of secondary species. It also requires that the budget of fast-reacting radicals that are directly involved in photochemical oxidation processes be investigated in detail. Here, we used a modified regional chemical transport model (the WRF-Chem) to analyze the influence of different photochemical processes on the entire geographical area covered by China. This analysis provides a quantitative estimate of the different factors that affect the oxidation capacity of the atmosphere in different regions of the country. Besides that, our model simulations will assess the relative importance of different photochemical processes that contribute to the budget of near-surface ozone in different chemical environments and provide some theoretical considerations on which our analysis is based. This study should support to reduction of ozone and other secondary pollutants in China.
Current and future drought hazards in the Flemish pear sector
Authors: Bamps Brecht , Gobin Anne , Somers Ben , Van Orshoven Jos
Published: February 2023

Recurring episodes of drought have become a hot topic in recent years in the Flemish pear sector. Damages associated with these episodes increasingly cause economic losses and create uncertainty for fruit growers. This trend is expected to continue in the future, as episodes of drought are likely to increase in frequency, intensity and duration as a result of climate change.This problem calls for the development of efficient risk management methods, which rely on accurate estimates of the hazard imposed by extreme weather. Therefore, our study aims to quantify the location-specific hazard and impact of past and projected drought episodes on pear orchard vigour and productivity in the region of Flanders (Belgium). The hazard under the recent past climate is characterised based on daily historical meteorological observations (1961-2022) with 5x5 km spatial resolution (Gridded Observational Dataset of the Royal Meteorological Institute of Belgium). The future hazard is determined based on daily regional climate model projections from the CORDEX ensemble (12.5x12.5 km spatial resolution). Climate projections are bias-corrected using Multivariate Quantile Mapping based on a N‐dimensional probability density function transform.Regional AquaCrop, a spatially distributed modelling system of the field-scale crop growth model AquaCrop1, is used to calculate the soil water balance on a daily timestep, covering the region of Flanders at a spatial resolution of 12.5x12.5 km. Phenology-dependant thresholds of critical values of the soil water potential are used to analyse the frequency, intensity, duration and timing of drought-related stress episodes for rainfed pear orchards (cv. Conférence). Moreover, changes in the characteristics of potentially damaging episodes of drought under future climates are analysed.Preliminary findings show an increase in projected frequencies of stress-inducing occurrences under Representative Concentration Pathway (RCP) 4.5 and RCP 8.5 for the period 2022-2072 compared to the reference period 1972-2022. Moreover, spatial variation in drought hazards for pear orchards across Flanders points to local environmental factors such as soil type and groundwater depth.The spatially explicit hazard maps associated with the future climatic conditions resulting from this analysis are useful for decision-making by fruit growers, governments and insurance companies. 1Raes, D., Steduto, P., Hsiao, T. C., and Fereres, E.: AquaCrop – the FAO crop model to simulate yield response to water: II. Main algorithms and software description, Agron. J., 101, 438–447, https://doi.org/10.2134/agronj2008.0140s, 2009.
Conformally-mapped planetary magnetosheath model
Authors: Narita Yasuhito , Toepfer Simon , Schmid Daniel
Published: February 2023

A high-precision model of steady-state plasma flow and magnetic field in the planetary magnetosheath region is proposed by introducing the concept of conformal mapping and transforming the Kobel-Flueckiger scalar potential (the exact solution of Laplace equation) from the parabolic boundaries (bow shock and magnetopause) into arbitrary shape of boundaries. While the statistically-confirmed bow shock and magnetopause models can often be extended to the complex plane by analytic contiuation, construction of conformal mapping in a general magnetosheath case turns out be a mathematical challenge. The reason for this is that the analytic continuation of the bow shock shape does not necessarily meet the analytic contination of the magnetopause shape in general. We overcome this problem and construct a numerical conformal mapping method for the magnetosheath with arbitrary bow shock and magnetopause shapes by (1) modeling shell-like envelopes that smoothly change vary between the two boundaries (the v-variables), (2) imposing the orthogonality condition to find normal directions to the envelopes (the u-variables), and (3) applying the u and v variables to the Kobel-Flueckiger potential. Our conformal mapping method serves as a reference model of magnetosheath, which is numerically inexpensive and is easily implemented. Analysis of in-situ measurement data and numerical simulations of the planetary magnetosheath region will significantly benefit from the conformal mapping method. Moreover, our method can be used to derive the upstream conditions (flow speed and magnetic field) using the magnetosheath data.
Stormwater management in volcanic islands using dry gallery infiltration systems
Authors: Marazuela Miguel Ángel , García-Gil Alejandro , Baquedano Carlos , Martínez-León Jorge , Cruz-Pérez Noelia , Santamarta Juan Carlos
Published: February 2023

Extreme precipitation events are expected to become more frequent in the coming years due to climate change, which together with the continuous development of cities and surface sealing that hinder water infiltration into the subsoil, is accelerating the search for new facilities to manage stormwater. The Canary Islands (Spain) are taking advantage of the knowledge acquired in the construction of water mines to exploit a novel stormwater management facility, which we have defined as a dry gallery. Dry galleries are constituted by a vertical well connected to a horizontal gallery dug into highly permeable volcanic layers of the vadose zone, from where infiltration takes place. However, the lack of scientific knowledge about these facilities prevents them from being properly dimensioned and managed. In this work, we simulate for the first time the infiltration process and the wetting front propagation from dry galleries based on a 3D unsaturated flow model and provide some recommendations for the installation and sizing of these facilities. The results demonstrate that stormwater infiltration from dry galleries is a highly transient process in which a sizing underestimation can be committed if unsaturated conditions or geological configuration are neglected.
Impact of gas emissions from oil and gas reservoirs on stable carbon isotope variability in tree rings
Authors: Churakova (Sidorova) Olga , Batalin Georgy , Gareev Bulat , Mingazov Gazinur , Terekhin Andrey , Tishin Denis , Kuzina Dilyara , Nurgaliev Danis
Published: February 2023

Accelerated development of energy resources around the world has significantly increased forest change associated with oil and gas activities, leading to both carbon dioxide and methane emissions. The impacts of these anthropogenic indirect greenhouse gases play a significant role on forest ecosystems at the regional and global scales.In this study we aim to reveal site-specific differences in stable carbon isotope (δ13С) variability of pine trees (Pinus sylvestris) growing on the territory of (i) oil and gas reservoirs located in Almetyevsk and Leninogorsk regions (Tatarstan Republic, Russian Federation) classified as “disturbed”; and (ii) in a remote “undisturbed” site in Raifa, which is located ca. 250 km away from the oil and gas deposits.Tree cores were sampled from the south- and north-facing sides of each of the nine trees for both study sites using a Pressler increment borer. The state-of-the-art classical dendrochronological method was applied for the tree-ring width measurements and cross-dating. Each annual ring was split using a sharp BA-170P NT blade under the Leica M50 microscope. Stable carbon isotope measurements were performed for each year separately using a Delta V Plus isotope mass spectrometer (Thermo Fisher Scientific, Germany) via a Flash HT Plus in constant flow mode. Based on the nine individual trees stable carbon isotope chronologies were developed from 1930 to 2022. Tree-ring δ13C in wood chronologies were corrected according to δ13C atmospheric CO2 for both study sites.Results of our study indicate significant differences between carbon isotope variability in tree rings from “disturbed” the oil and gas deposits site, which is rapidly developed over the recent decades compared to the “undisturbed” natural forest site.This work was funded by the Kazan Federal University Strategic Academic Leadership Program (PRIORITY-2030). 
High-latitude, high-altitude seismic stations on Mt. Erebus, Antarctica
Authors: Cramer Avilash , Hunt Madeline , Arnell Kirsten , Horton Alan , Stanford Susan , Anderson Kent , Beaudoin Bruce
Published: February 2023

Mt Erebus, the world’s southernmost active volcano, is only 30 miles from McMurdo Station (US) and Scott Base (NZ). Scientific instruments deployed on the volcano need to survive a range of environmental factors including high winds, extreme cold, lava bombs, and months of total darkness. Additionally, the reduced air pressure at high elevations affects the lift of the helicopters and the physiology of the engineers during installation.We present a novel design for a network of environmentally hardened seismic stations intended specifically for the constraints of this polar volcano. The purpose of the network is to provide a baseline measurement of volcanic events and act as a fiducial array for future experiments. Stations are designed to function continuously over both summer and winter for years at a time. The station’s instrument package comprises a data logger recording broadband seismic and infrasound data, and a second data logger recording strong-motion seismic data.  The station design is modular and can be scaled for various experiment requirements and easily adapted for different instrument packages.Station state-of-health will be monitored at the EarthScope Primary Instrument Center (EPIC, formerly IRIS PASSCAL) and low sample rate (20 sps) broadband data are transmitted by Iridium modems and captured in near-real time. Higher sample rate (100-200 sps) data are recorded locally and collected annually during the austral summer. All data will be available from the EarthScope Data Management Center (network codes 1G, 8E, and 2H).A prototype was installed near McMurdo station in 2021/22 season and evaluated over the Antarctic winter. Based on this prototype, four stations recording data from nine instruments were installed around Mt Erebus in the 2022/23 season. An additional three stations of an older design that are recording data from five instruments were installed in previous seasons as part of an interim network. These stations will be upgraded to the new design in upcoming seasons.Our talk will center on the following three components:1) the electrical and mechanical design of this new station, including power electronics, satellite telemetry, insulation, and rigging;2) the logistics of Antarctic volcanology, including site selection, geographical constraints, and US Antarctic Program helicopter operations;3) recent results and future plans for maintaining and upgrading seismic networks on Mt. Erebus.
Quantifying windstorm risks by translating historical extreme events into the future
Authors: Hawkins Ed , Brohan Philip , Burgess Samantha , Burt Stephen , Compo Gilbert , Gray Suzanne , Haigh Ivan , Hersbach Hans , Kuijjer Kiki , Martinez-Alvarado Oscar , McColl Chesley , Schurer Andrew , Slivinski Laura , Williams Joanne
Published: February 2023

Extreme wind events are among the costliest natural disasters in Europe. Significant effort is dedicated to understanding the risk of such events, usually analysing observed storms in the modern era. However, it is likely that some historical windstorms were more extreme and/or followed different tracks from those in the modern era. Producing plausible reanalyses of such events would improve the quantification of current and future windstorm risks.Billions of historical climatological observations remain unavailable to science as they exist only on paper, stored in numerous archives around the world. We demonstrate how the rescue of such paper observations has improved our understanding of an extreme windstorm that occurred in February 1903 and its significant impacts. By assimilating newly rescued atmospheric pressure observations into the 20th Century Reanalysis system, the storm is now credibly represented in an improved reanalysis of the event. In some locations this storm produced stronger winds than any event during the modern era. As a result, estimates of risk from severe storms, based on modern period data, may need to be revised. Simulations of the storm surge resulting from this storm show a large coastal surge of around 2.5m, comparing favourably with newly rescued tide gauge observations and increasing our confidence in the quality of the reconstruction.In addition, we use novel reanalysis experiments to translate this windstorm into a warmer world to quantify how it might be different both in the present and in the future. We find that the same storm produces more intense rainfall and stronger winds in a warmer climate, providing a new approach to quantifying how extreme weather events will change as the world is warming.
Harmonising the sharing of marine observation data considering data quality information
Authors: Jirka Simon , Autermann Christian , Del Rio Fernandez Joaquin , Konkol Markus , Martínez Enoc
Published: February 2023

Marine observation data is an important source of information for scientists to investigate the state of the ocean environment. In order to use data from different sources it is critical to understand how the data was acquired. This includes not only information about the measurement process and data processing steps, but also details on data quality and uncertainty. The latter aspect becomes especially important if data from different types of instruments shall be used. An example for this is the combined use of expensive high-precision instruments in conjunction with lower-cost but less precise instruments in order to densify observation networks.Within this contribution we will present the work of the European MINKE project which intends, among further objectives, to facilitate the quality-aware and interoperable exchange of marine observation data.For this purpose, a comprehensive review of existing interoperability standards and encodings has been performed by the project partners. This included aspects such as:standards for encoding observation data
standards for describing sensor data (metadata)
Internet of Things protocols for transmitting data from sensing devices
interfaces for data access
From a technical perspective, the evaluation has especially considered developments such as the OGC API family of standards, lightweight data and metadata encodings, as well as developments coming from the Internet of Things community. This has been complemented by an investigation of relevant vocabularies that may be used for enabling semantic interoperability through a common terminology within data sets and corresponding metadata.Furthermore, specific consideration was given to the description of different properties that help to assess the quality of an observation data sets. This comprises not only the description of the data itself but also quality related aspects of data acquisition processes. For this purpose, the MINKE project is working on recommendations how to enhance the analysed (meta) data models and encodings with further elements to better transport critical information for better interpreting data sources with regard to the accuracy, uncertainty and re-usability.Within our contribution we will present the current state of the work within the MINKE project, the results achieved so far and the practical implementations that are performed in cooperation with the project partners.
HSS/CIR driven storm effects on the ionosphere-thermosphere system
Authors: Prasannakumara Pillai Geethakumari Gopika , Aikio Anita , Cai Lei , Vanhamaki Heikki , Pedersen Marcus , J. Coster Anthea , Marchaudon Aurelie , Blelly Pierre-Louis , Haberele Veronika , Maute Astrid , Ellahouny Nada , Virtanen Ilkka , Norberg Johannes , Oyama Shin , Kozlovsky Alexander , Grandin Maxime
Published: February 2023

Solar wind interactions with the Earth’s magnetosphere cause geomagnetic storms and thereby induce ionospheric storms. This study investigates the spatio-temporal evolution of the ionospheric Total Electron Content (TEC) during a moderate but long duration storm driven by solar wind high-speed streams (HSSs) and associated co-rotating interaction region (CIR) during 14-21 March 2016. The storm starts with a strong storm sudden commencement (SSC) with a peak close to 19 UT on 14 March 2016. The GNSS/TEC maps are obtained from the Madrigal database. The associated field-aligned currents (FACs) from AMPERE, ionospheric convection maps from SuperDARN, and the O/N2 ratio from TIMED/GUVI are also studied for understanding the physics behind the different features observed in TEC during the storm.The study predominantly focuses on the changes of TEC at high and middle latitudes. The storm induced changes in the TEC were extracted by removing the quiet time background (mean of five quietest days of the month) from the TEC maps. During the initial phase, TEC enhancements and depletions are found mainly at high latitudes within the auroral oval and close to the cusp, plausibly associated with auroral precipitation and variations in the upward and downward field-aligned currents (FACs). After the onset of the main phase, the TEC is enhanced at mid-latitudes and auroral ovals with a maximum of ~10 TECU. Meanwhile, a significant decrease in TEC is observed in the polar cap region. During the main phase, we observe the evolution of a storm-enhanced-density (SED) plume and a transient enhancement of TEC in the polar cap. Later during the storm, a strong TEC depletion at high and middle latitudes is found on the dayside and in the evening sector. The depletion of O/N2 ratio, triggered by Joule heating and atmospheric upwelling, could be a plausible reason for the TEC depletion. The possible physical mechanisms associated with the observed TEC variations will be discussed. 
Unveiling global patterns of forest phenological diversity and their long-term changes
Authors: Girardello Marco , Ceccherini Guido , Duveiller Gregory , Migliavacca Mirco , Cescatti Alessandro
Published: February 2023

Land-surface phenology is a widely used indicator of how terrestrial ecosystems respond to environmental change. The spatial variability of this ecosystem functional property has also been advocated as an indicator of the functional composition of ecosystems. However, a global-scale assessment of spatial patterns in the spatial heterogeneity of forest phenology is currently lacking. To address this knowledge gap, we developed an index based on satellite retrievals and use it to quantify phenological diversity across global forest biomes. We show that there is considerable variation in phenological diversity among biomes, with the highest overall levels occurring in arid and temperate regions. An analysis of the drivers of the spatial patterns revealed that phenological diversity is primarily determined by temperature-related factors. Furthermore, an assessment of temporal changes over an 18-year period revealed strong climate-driven shifts in boreal and arid regions, suggesting that there may be an ongoing widespread homogenization of phenological strategies within forest ecosystems. Our findings ultimately contribute to the development of a novel ecosystem-level Essential Biodiversity Variable (EBV), which may enable scientists and practitioners to quantify the functional composition of ecosystems at unprecedented spatial and temporal scales.
Indicators of tropical forest resilience in vegetation models
Authors: Bathiany Sebastian , Nian Da , Boers Niklas
Published: February 2023

The resilience of tropical forests against climate change and deforestation is vital for biodiversity and carbon drawdown. This resilience is hard to measure directly, but is suspected to be decreasing. There is particular concern that the Amazon rainforest may be approaching a “tipping point” where the large-scale loss of species and carbon pools amplifies substantially. Candidate mechanisms for such threshold effects often involve positive feedbacks and span a large range of scales. For example, individual trees can die from hydraulic failure when soil moisture decreaseses, forest fires can mediate a regional transition to a savanna state, and by synchronising remote regions, the moisture recycling feedback could cause a continental-scale forest dieback. Conceptual dynamical systems suggest that the loss of resilience that accompanies such transitions can be measured by statistical indicators like increasing autocorrelation. Satellite observations of vegetation indices related to greenness and biomass seem to support these theoretical expectations.Here we analyse dynamic global vegetation models (DGVMs) from CMIP6, as well as idealised simulations with LPJ, in order to bridge the complexity gap between conceptual models and the real world. First, we assess how resilience of terrestrial carbon pools in the tropics depends on mean annual rainfall (MAP). We find that this relationship differs between models, and can also differ substantially from the observed positive relationship, depending on how the models capture carbon pool dynamics on the grid-cell level. Second, we show that changes in resilience do not necessarily require any atmosphere-vegetation feedbacks, fire feedback or ecological interactions, suggesting that observed relationships may capture physiological effects in individual trees rather than the stability of the entire forest. Third, we also find that the coexistence of vegetation types affects vegetation resilience in DGVMs. In particular, plant types with faster dynamics can replace slower ones (e.g., grass replacing trees), leading to decreased autocorrelation but not necessarily larger sensitivity to MAP. We conclude that suitable indicators of tropical vegetation resilience should be determined by (i) using DGVMs to understand better what mechanisms are at play, and (ii) using observations to rule out certain model approaches (e.g. area-averaged versus individual-based models).
Assimilating GRACE Total Water Storage Anomalies into hydrological forecasts in order to acquire information for groundwater level changes
Authors: Gemitzi Alexandra , Stathopoulos Stavros
Published: February 2023

The present work aims at assimilating GRACE Total Water Storage Anomalies (TWSA) into hydrological forecasts in order to estimate groundwater level changes. The motivation of our research was to provide information for groundwater levels and storage changes along with the rest of hydrological parameters provided usually by hydrological models, i.e., surface runoff, lateral flow contribution to stream flow, groundwater contribution to stream flow, water percolation below the soil profile, soil water and evapotranspiration. Therefore, we investigated a possible approach to acquire information on the groundwater regime of a watershed assimilating downscaled GRACE TWSA along with two variables related to groundwater flow obtained from the application of SWAT model, i.e., groundwater contribution to stream flow and percolation. The methodology was developed and tested in a medium sized river basin (~360 km2) in NE Greece, namely Vosvozis river basin. Initially we checked for possible correlation of the downscaled GRACE TWSA with the groundwater level anomalies for the period 2013 – 2021. Results indicated that downscaled GRACE TWSA can be used as possible predictor for groundwater level changes. Thereafter, two model approaches were evaluated for their predictive ability regarding groundwater level changes. The first approach is a Multiple Linear Regression (MLR) model whereas the second was an Artificial Neural Network Multilayer Perceptron (MLP-ANN) model. Both models indicated a satisfactory performance with R2 values ranging from 0.76 – 0.78 for the MLR model, in the training and testing phases, whereas the MLP-ANN outperformed in both phases the MLR model, with R2 ranging well above 0.8, indicating its predictive ability for groundwater level changes. The methodology can be applied parallel to SWAT model and groundwater level changes can be acquired simultaneously with the rest of hydrological variables.      
Atmospheric CO2 removal by alkalinity enhancement in the North Sea
Authors: Liu Feifei , Daewel Ute , Kossack Jan , Schrum Corinna
Published: February 2023

Increased ocean alkalinity reduces the activity of CO2 in seawater and prompts an enhanced flux of CO2 from the atmosphere into the ocean, thereby provides a promising means to reduce the atmospheric CO2 concentrations. However, due to the high complexity of physical and biological processes in coastal waters, the possible effects of coastal alkalinity enhancement (AE) are unclear yet. We thereby aim to set up a model framework to simulate the carbon cycles in the North Sea, which further allows scenario studies to disentangle the efficiency of various forms of coastal AE measures as well as their side effects and ecosystem impacts on the Northwest European Shelf (NWES) system. In two scenarios, the same quota of alkalinity is added into two designated areas, the European coast and the middle North Sea along with the ship tracks, respectively. The alkalinity is distributed continuously and evenly into the two areas. Our results indicate that the North Sea is quickly adjusted to both AE deployments, given that the AE efficiency shows no significant trend since the second year of these deployments. Seasonally, AE is more efficient in wintertime. The efficiency reaches the lowest level in spring, implying that the ocean uptake of the atmospheric CO2 is dominated by biological processes during this season. This modelling assessment will serve as a guide for coastal management and policy making that allows reconciling the application of Carbon Dioxide Removal (CDR) techniques with the maintenance of a good environmental status. It thereby offers an important yet unprecedented case study for a regional to local CDR deployment in the proximal coastal ocean of a temperate shelf sea.
Spatial distribution and changes in the debris flow hazard across High Mountain Asia
Authors: Bazilova Varvara , de Haas Tjalling , Immezeel Walter
Published: February 2023

Debris flows and floods and flash floods pose hazards to the densely populated areas of High Mountain Asia (HMA). The continuous decline in the cryosphere across the region such as glacier mass loss and permafrost thaw leads to exposure of the unconsolidated debris material and sediment deposits. This has led to changes in the magnitude and frequency of debris flows and floods. We aim to identify the controlling parameters and quantify the likelihood of debris flow and floods and the change in likelihood due to projected regional climate and cryosphere changes. Based on visual inspection of alluvial deposition and surface properties of the alluvial fans, we identified catchments across HMA where floods or debris flows occur. We built a database with morphometrical (e.g. catchment area, perimeter, slope, elevation range, Melton ratio) and climatic features (e.g. temperature and precipitation regime, freeze – thaw cycles, glacier and permafrost area) and build a CatBoost gradient boosting based machine learning classifier. We identify that debris flows are more likely to occur in small catchments, defined as catchments with small Melton ratio and high slope. Projected regional climate change will decrease the probability of the debris flows. It will also increase the probability of the flood being a dominant process in the catchment across the entire HMA.

 

 

 
Developing Deep Learning Methods for Surface NO2 Estimation from GEMS Satellite Data
Authors: Gödeke Janek , Hong Hyunkee , Richter Andreas , Maaß Peter , Lange Kezia , Lee Hanlim , Park Junsung
Published: February 2023

Recent works on using Machine Learning methods for deriving estimates of the NO2 concentration at the Earth's surface from satellite observations exploit measurements taken from low Earth orbits, e.g. from the TROPOMI instrument on the Copernicus Sentinel-5P satellite. However, given geographic location, the time resolution is quite low, with a single measurement per day, which leads to rather small data sets. In order to increase the performance of Machine Learning methods, large data sets would be desirable.Launched in 2019, the Korean Geostationary Environmental Monitoring Spectrometer (GEMS) mission has been the first geostationary satellite mission for observing trace gas concentrations in the Earth's atmosphere over Asia. Geostationary orbits allows for hourly measurements, which leads to a much higher temporal resolution compared to measurements taken from low Earth orbits. Within the next years, two further geostationary missions will follow: NASA‘s TEMPO and ESA‘s Sentinel-4 mission, providing additional data with high temporal resolution over North America and Europe.One of the GEMS level-2 data products is the NO2 tropospheric vertical column density (VCD). In our research project we discuss and develop Deep Learning methods that use not only these NO2 VCDs, but also additional data such as meteorological and geographical data, to derive estimates of the NO2 surface concentration in high spatial as well as high temporal resolution, enabled by the geostationary GEMS measurements mentioned above. The validation of the network‘s prediction is realized by the consideration of in-situ NO2 observations from the air quality network of South Korea.
Assessing fire danger synchronicity in Europe
Authors: Gincheva Andrina , Moreno Alberto , Jerez Sonia , Montávez Juan Pedro , Turco Marco
Published: February 2023

This contribution seeks to better understand recent changes in synchronous fire danger across Europe that can overwhelm fire suppression capacity. We analyze the spatio-temporal synchronicity of fire danger in Europe over the period 1979-2021 based on the Canadian Fire Weather Index, one of the most commonly used fire indices globally (FWI; Vitolo et al. 2020). The daily synchronicity index indicates the total area with a level of FWI above 50, that represents the extreme fire danger threshold as classified by the European Forest Fire Information System (EFFIS). The annual mean surface affected by synchronicity extreme fire danger increased by about 100000 km2 over the 42-year-long study period (i.e. 57% of the mean historical value). The expansion of synchronized fire potential can compromise fire management efforts.ReferencesVitolo, C., Di Giuseppe, F., Barnard, C., Coughlan, R., San-Miguel-Ayanz, J., Libertá, G., & Krzeminski, B. (2020). ERA5-based global meteorological wildfire danger maps. Scientific data, 7(1), 1-11.AcknowledgmentsWe acknowledge funding through the project ONFIRE, grant PID2021-123193OB-I00, funded by MCIN/AEI/ 10.13039/501100011033. A.G. thanks the Ministerio de Ciencia, Innovación y Universidades of Spain for PhD contract FPU19/06536.
Numerical optimization of drinking water distribution network design: ideas and questions provided by practice
Authors: van Laarhoven Karel , Hillebrand Bram , Mitrovic Djordje , Vertommen Ina
Published: February 2023

In the past decades, the potential of numerical optimization for the automated design of drinking water distribution networks has been extensively studied. In particular, evolutionary algorithms have been shown to be a powerful and versatile tool for several design tasks. In the past few years in the Netherlands, drinking water utilities have started to embrace this approach more and more to explore new design philosophies as well as to address immediate asset management decision challenges. Key to meaningful application has been the possibility to iteratively and flexibly develop the optimization problem throughout the design process. The traditional 'benchmark problems' from academia provide a strong starting point for a design process, giving utility experts a taste of the possibilities. Subsequently, however, the problem definition has to be adapted and fine-tuned in order to keep up with the evolving perspective of the utility experts on the design problem. During this type of practical implementation, it frequently occurs that questions emerge which greatly increase the complexity of the optimization task without an approach being readily available from scientific literature, requiring workarounds to be created on the spot. Here, we present recent examples of such questions and their workarounds, which we ran into while tackling different practical design challanges, namely: how to incorporate topology optimization into regular pipe dimension optimization for a network in Belgium; how to incorporate topology and project cost optimization into sectorization of the network of The Hague; and how to incorporate optimal utilization of different water sources into regular pipe dimension optimization of the water distribution network of Amsterdam.
First observations of Deimos from the Emirates eXploration Imager (EXI)
Authors: Osterloo Mikki , Edwards Christopher , Fisher Charles , Jeppesen Chris , Wolff Michael , Jones Andrew , Knavel Justin , Pilinski Emily , Tomso Christopher , Shuping Ralph , Deighan Justin , Al Matroushi Hessa
Published: February 2023

The Emirates Mars Mission (EMM) has a unique opportunity to observe the surface of Deimos, the smaller and outermost of the two moons of Mars. The origins of both Phobos and Deimos remain debated largely due to lack of available observations. The elliptical orbit of the EMM spacecraft, designed to provide comprehensive coverage of the martian atmosphere, allows for campaigns to periodically observe the moon. The slight adjustment of the orbit to move into a resonance with Deimos permits nominal science to continue. The campaign began in August of 2022 by undertaking a series of maneuvers to enable several flybys each stepping in and progressively attaining a closer distance to Deimos. Here, we will present the images collected by EXI of the targeted flyby (e.g., the flyby wherein the spacecraft achieves its closest distance to the moon). Observations for each flyby will include an initial image set at the start of the approach (red/green/blue/320 nm/260 nm), red images will be acquired at 1 min intervals during the approach, and when the spacecraft is at the closest point to Deimos a red/green/blue image set at full resolution, as well as a 320 nm image binned at 2×2 pixels, will be acquired. As the spacecraft leaves Deimos, the reverse observation strategy will be employed. These observations will help constrain the short-wavelength spectral properties and further characterize the geomorphology of this relatively understudied martian moon.
Using Distributed Fiber-optic Sensing for Tracking Caprock Fault Activation Processes
Authors: Rodríguez Tribaldos Verónica , Hopp Chet , Soom Florian , Guglielmi Yves , Cook Paul , Shadoan Tanner , Ajo-Franklin Jonathan , Robertson Michelle , Wood Todd , Birkholzer Jens
Published: February 2023

Identifying and monitoring the reactivation of faults and opening of fractures affecting low permeability, sealing formations in natural underground storage complexes such as Carbon Capture and Storage projects and Nuclear Waste repositories is essential to ensure storage integrity and containment. Although passive seismic monitoring can be effective for detecting induced failure, stress accumulation and fault reactivation can occur aseismically in clay-rich formations, preventing early failure to be recognized. Here, we investigate the potential of applying strain monitoring with fiber-optics sensing technologies to assess in-situ changing stress conditions at high spatial and temporal resolution.We present results of fiber-optic sensing monitoring during the FS-B experiment, a controlled activation of a fault zone affecting the Opalinus Clay Formation in the Mont Terri underground Laboratory (Switzerland). Six constant flowrate water injections induced the hydraulic opening of the fault. A hydraulic connection between the injector and a monitoring borehole occurred, developing a flow path sub-parallel to the fault strike. A 2 km long fiber-optic cable looped through 10 monitoring boreholes surrounding and crossing the fault zone was used for distributed acoustic and strain sensing (DAS and DSS) before, during and after injection. Continuous low-frequency (< 1 Hz) DAS data reveals mechanical strain associated with fault reactivation. Increasing extensional strain is recorded near the point of injection and near the newly formed hydraulic flow path, reaching a value of ~150 μɛ. Post-activation residual strain of ~60 μɛ suggests irreversible fault zone deformation. Smaller strain changes are recorded above and below the high pressure flow path, suggesting a mechanically disturbed zone larger than the leakage zone. Low-frequency DAS data are consistent with co-located DSS strain data, local, 3D displacement measurements of fault movements and P-wave velocity anomalies derived from Continuous Active Source Seismic Monitoring (CASSM). Our results are promising and demonstrate the potential of fiber-optic sensing as a powerful tool for monitoring spatio-temporal evolution of fault reactivation processes and leakage in clay formations induced by fluid pressurization.
Rethinking green roofs- natural and recycled materials improve their carbon footprint
Authors: Nehls Thomas , Tams Laura , Calheiros Cristina Sousa Coutinho
Published: February 2023

Green roofs are promoted to deliver climate regulation and urban heat island mitigation and many more. Ecosystem services of green roofs are discussed generally positively, but their footprint from production and demolition processes have not been fully addressed. In this study, a life cycle analysis (LCA) was conducted to assess the possibility of creating of a carbon-neutral green roof and to evaluate and compare the global warming potential (GWP) of two green roofs: 1) a conventional green roof (GR-c) with expanded clay, pumice, and compost in the substrate and a polypropylene drainage, and 2) an eco-friendly green roof (GR-a) with recycled bricks and compost in the substrate and a cork drainage. The LCA refers to a functional unit (FU) of a 218 m2 green roof (substrate depth of 9 cm; lifespan of 40 years). The results showed that the use of a brick substrate can reduce the GWP to 3139 kg of CO2 eq/FU (- 50%) and the use of cork drainage to 441 kg of CO2 eq/FU (- 69%). Apart from production, demolition is a key process  to be improved in future, accounting for 32% (GR-c) and 55% (GR-a) of the GWP. Once produced, a green roof can take up 783 gCO2/(m2⋅a) because of plant uptake. To become CO2-neutral, a GR-c and GR-a would have to last 88 and 53 years, respectively. Furthermore, the GWP was influenced by green roof maintenance and plant CO2 uptake. We conclude that recycled bricks and cork are promising green roof materials.
Persistent Activity and Crater Formation at Telica Volcano Driven by the Shallow Hydrothermal System
Authors: LaFemina Peter , Saucier Emilie , Feineman Maureen , Saballos Armando
Published: February 2023

Telica volcano is a persistently restless volcano with activity expressed as long-lived high-temperature fumaroles and magmatic degassing, high rates of background seismicity and frequent (sub-decadal) explosive, phreatic to phreatomagmatic eruptive activity. We are studying this system through the combination of geophysical, geochemical, and geologic observations and analyses. To date our observations and analyses indicate: 1) long-lived fumaroles and subsequent hydrothermal alteration of the crater walls lead to regions of preferential crater wall collapse into the active the crater; and 2) hydrothermal alteration and mineralization within the shallow hydrothermal system leads to sealing of the conduit, a build-up of pressure and explosions. The partial to complete sealing of the top of the volcanic conduit is thought to occur through the deposition of salts and silicate minerals from hydrothermal fluids, moving the volcano from an open to a closed system. The formation of a seal is observed indirectly by the eruption of hydrothermal mineral species and altered rock, decreases in measured gas flux, thermal anomalies, and LF seismicity that indicates a decrease in gas flow, and deformation of the volcanic edifice due to the increase in pressure from gas accumulation. Additionally, the eruption of a small volume lava dome in 2017 indicates the presence of highly viscous basaltic andesite magma in the conduit, which may also contribute to sealing of the conduit and the observed deformation. Here, we model cGPS displacement time series based on our conceptual model for the transition from an open to a closed system, utilizing our disparate, but complimentary data sets, including gas flux, terrestrial and remotely sensed thermal, web camera and cGPS displacement time series. Our numerical model incorporates changes in permeability of the conduit due to mineralization and the subsequent accumulation of gas beneath the seal. The increase of pressure due to sealing of the system and rising magma eventually leads to failure of the seal and phreatic explosions. Improving our knowledge of this transition from an open to closed system is important for understanding Telica’s eruptive processes and hazards, as well as gaining a better understanding of how this transition could manifest at other volcanic systems.