bluuebunny/crossref_metadata_2025 huggingface dataset:
A pinnacle-like structure dominated by the chemosymbiotic bivalve Thyasira from the Arctic Sea
Authors: Riva Marta , Bracchi Valentina Alice , Argentino Claudio , Savini Alessandra , Fallati Luca , Panieri Giuliana , Basso Daniela
Published: February 2023

The West‐Svalbard continental slope represents one of the northernmost gas hydrate provinces in the world. It is located on the western Svalbard margin in the eastern Fram Strait at ~79°N, north of the Knipovich Ridge and Molloy transform fault, situated on a hot and relatively young oceanic crust. The project Advancing Knowledge of Methane in the Arctic (AKMA), funded by the Norwegian Research Council, explores Arctic methane sources, processes, ecosystems and geological history in part of this province. During a dedicated research expedition (CAGE21-1-AKMA) a spectacular pinnacle-like structure has been identified at 914 m of water depth in the area of the north Kniponich Ridge, during the exploration by remotely operated vehicle. The structure is located at the base of a small-scale escarpment, typified by the presence of carbonate slabs. It is more than 1 m in height, has a diameter of at least 50 cm, and appears isolated on a flat seafloor with muddy-dominated heterogeneous sediment. From the video, the structure was apparently composed of dead bivalves cemented in a substrate of finer particles. Many bivalves were still articulated and with their valves closed, although no sign of living bivalves could be detected. Living regular echinoids, one large crinoid, several sponges and a few soft corals colonized the surface at the time of observation. Small samples have been collected from the surface of this fossil bivalve pinnacle. These samples supported the video-based interpretation of a fossil structure composed of cemented and carbonate-encrusted dead valves, among which the most abundant and the largest specimens belong to Thyasira cf capitanea, both juvenile and adult. The valves, either articulated or disarticulated, are often cemented by a white thick (3 mm) authigenic carbonate crust that binds together the mollusk shells, but also encrusts some of them internally. This means that these crusts continued to grow also after the death of the mollusks, when some of the valves were open. Additional interesting benthic fauna recognized in the cement includes small gastropods and foraminifers. The genus Thyasira has already been described as a typically chemosymbiotic group of species and as such, it has been reported from active cold seeps in the Arctic, as well as in other geographic areas and in the geologic record. We interpret the pinnacle as fossil evidence of a site of past methane emission, possibly exhumed by recent erosional or gravity-driven resedimentation processes.
Stratospheric water vapor affecting atmospheric circulation
Authors: Charlesworth Edward , Plöger Felix , Birner Thomas , Baikhadzhaev Rasul , Abalos Marta , Abraham Luke , Akiyoshi Hideharu , Bekki Slimane , Dennison Fraser , Jöckel Patrick , Keeble James , Kinnison Doug , Morgenstern Olaf , Plummer David , Rozanov Eugene , Strode Sarah , Zeng Guang , Riese Martin
Published: February 2023

Water vapor plays an important role in many aspects of the climate system, by affecting radiation, cloud formation, atmospheric chemistry and dynamics. Even the low stratospheric water vapor content provides an important climate feedback, but current climate models show a substantial moist bias in the lowermost stratosphere. Here we report crucial sensitivity of the atmospheric circulation in the stratosphere and troposphere to the abundance of water vapor in the lowermost stratosphere. We show from a mechanistic climate model experiment and inter-model variability that lowermost stratospheric water vapor decreases local temperatures, and thereby causes an upward and poleward shift of subtropical jets, a strengthening of the stratospheric circulation, a poleward shift of the tropospheric eddy-driven jet and regional climate impacts. The mechanistic model experiment in combination with atmospheric observations further shows that the prevailing moist bias in current models is likely caused by the transport scheme, and can be alleviated by employing a less diffusive Lagrangian scheme. The related effects on atmospheric circulation are of similar magnitude as climate change effects. Hence, lowermost stratospheric water vapor exerts a first order effect on atmospheric circulation and improving its representation in models offers promising prospects for future research.
geokube: A Python Package for Data Analysis and Visualization in Geoscience
Authors: Mancini Marco , Stojiljkovic Mirko , Walczak Jakub
Published: February 2023

geokube is a Python package for data analysis and visualisation in geoscience that  provides high level abstractions in terms of both Data Model, inspired by Climate Forecast and Unidata Common Data Models, and Application Programming Interface (API), inspired by xarray. Key features of geokube are the capabilities to: (i) perform georeferenced axis-based indexing on data structures and specialised geospatial operations according to different types of geo scientific datasets like structured grids, point observations, profiles etc. (e.g. extracting a bounding box or a multipolygon of variable values defined on a rotated pole grid), (ii) perform operations on the variables that are either instantaneous or defined over intervals, (iii) convert to/from xarray data structures and to read/write CF-compliant netCDF datasets.
Bathyal bivalve assemblages of the eastern Mediterranean record the Early-Middle Pleistocene transition
Authors: Koskeridou Efterpi , Thivaiou Danae , Agiadi Konstantina , Quillévéré Frédéric , Moissette Pierre , Cornée Jean-Jacques
Published: February 2023

Molluscs, and among them bivalves, are organisms known for their ability to precisely record paleoenvironmental changes, both in shallow and deep marine settings. When looking into the recent geological past, bivalve assemblages offer information on the climatic changes that have impacted their taxonomic compositions. In the eastern Mediterranean, assemblages of bathyal bivalves are scarce. In order to investigate the impact of climatic changes on deep-water bivalve communities during the Early-Middle Pleistocene Transition, we focus here on two well-dated sections on Rhodes Island (Greece) corresponding to the Lindos Bay Formation. The sections of Lindos and Lardos present a continuous sedimentation of fine, marly sediments, and cover the Marine Isotopic Stages (MIS) 32 to 18. A total of 15 samples were analysed, resulting in the recovery of 31 species of bathyal bivalves. The depositional depths of these samples are estimated to be between 150 and 500 m. All samples are dominated by Protobranch bivalves, with the larger diversity found in families Nuculanidae and Yoldiidae. Three species, found only in cool intervals, are now extinct: Ledella nicotrae, Katadesmia confusa, and Pseudoneilonella pusio. Differences in sample composition are thought to be due mainly to climatic rather than bathymetric conditions. Although the associations in most MIS are similar to those found in the Italian Pleistocene deposits, those of the MIS 21 interglacial (Nucula nucleus – Saccella commutata – Cyclopecten hoskynsi – Limea crassa) and the MIS 20 glacial (Saccella commutata – Bathyspinula excisa –Yoldiella curta – Bathyarca spp.) are new for the Mediterranean region. These results imply that there were significant changes in bathyal bivalve associations during the climatic transitions of the Early-Middle Pleistocene and that modern bathyal associations of bivalves have been stabilized after the Middle Pleistocene.
Pleistocene opening of the Ouarzazate Basin, and incision rate history of the Draa canyon in the Anti-Atlas of Morocco revealed by 10Be cosmogenic nuclide dating and non-linear river profile inversion
Authors: Babault Julien , Owen Lewis A. , Arroucau Pierre , Charco María , Bodet Ludovic , Van Den Driessche Jean , Caffee Marc
Published: February 2023

Records of incision history such as topographic data and landform dating can be gathered in inversion schemes to reconstruct base-level fall and uplift history. Here, we use a non-linear inversion scheme and the stream power incision model to study the landscape evolution of a mountainous area to quantify whether it responds to an uplift or a capture-induced local base-level fall. Our inversion is constrained by 10Be cosmogenic nuclide data. The probabilistic approach yields an ensemble of solutions made by a combination of model parameters. We apply our model to the Draa Canyon located in the Anti-Atlas of Morocco at the outlet of the Ouarzazate Basin which was internally drained during the Miocene. We show that incision rates in the Ouarzazate Basin and the southern margin of the High Atlas are compatible with a Pleistocene age for the opening of the Basin. The forcing to drainage integration may be due to capture by regressive erosion in the proto Draa river or tilting to the south of the High Atlas, Ouarzazate basin, and Anti-Atlas as a whole in response to mantle-related continental-scale uplift, or a combination of both. The southern border of the High Atlas in this region displays a transient landscape previously interpreted as evidence for recent shortening and rock uplift. Our results suggest that the rejuvenation of the southern Central High Atlas, in the northern margin of the Ouarzazate Basin, mainly occurred in response to the opening of the Ouarzazate Basin, with only several hundreds of meters of rock uplift localized along the South Atlas front during the late Cenozoic.
Assessing urban green space area and quality using remote sensing and population data: A case study of Hanoi urban districts
Authors: Reimuth Andrea , Nong Duong Huu , Ngo Son Thanh
Published: February 2023

Expansion of built-up areas has consumed large areas of natural ecological patches in many cities around the world, affecting environmental and living quality of urban residents.  Managing urban landscape and urban trees has gained a special attention in Vietnam in recent years. The green space development plan for Hanoi to 2030 and a vision to 2050 has targeted to reach 62% of green spaces. However, there is lack of detailed green space development plan at the district and commune/ward levels. This study aims to assess urban green space area and quality in Hanoi at the commune/ward levels using remote sensing and population data. The study uses combined remote sensing data from Google Earth, Sentinel-2, and Normalized Difference Vegetation Index (NDVI) to analyze urban green quality and space for Hanoi. The urban green space will be combined with population data at commune/ward level to estimate urban tree cover per person. The research results can contribute to improve the credibility and scientifically of green space construction so that urban planning can adapt and serve the city and its residents and achieve green development.
Forecasting landslide occurrence from radar rainfall at the municipality scale : a case study in a Mediterranean climate context in France
Authors: Bernardie Séverine , Viaggio Stefania , Marcot Nathalie , Drouillas Yoann , Vandromme Rosalie , Lebourg Thomas
Published: February 2023

Improving the resilience of territories to landslides is a rising need for security managers in a context of climate change, with the increase in frequency and intensity of extreme events. The French department of the Alpes-Maritimes has experienced numerous heavy rainfall occurences  over the last two decades, among which the particularly intense events of November 2019 and October 2020 (known as Storm Alex) should be mentioned. During these intense events, the Menton municipality has experienced several damaging landslides. In this context, it is necessary to develop innovative operational systems, based on rainfall data, which is a fundamental physical parameter for triggering landslides. In this study, we propose to develop a tool for landslide prevention at a municipality scale. For that, a fine-tuned approach is proposed : we uses a physical based model to estimate the landslide susceptibility induced by meteorological events, with considering the influence of groundwater level evolution on slope stability. This distributed model is based on a limit equilibrium method that computes Safety Factor along 2D profiles over the entire area. Then a hydrogeological model has been applied for estimating the daily local piezometric level, based on meteorological parameters (rainfall, snowmelt, evapotranspiration...) that might evolve in response to rainfall. Spatialized radar rainfall data has also been introduced and has made it possible to improve the temporal and spatial accuracy of susceptibility maps, by making them "dynamic" and thus facilitating real-time forecasting. This analysis is now possible by setting up a processing chain that, starting with the radar measurement of rainfall (grid resolution 1km²) and through the computation of the corresponding groundwater level, allows a landslide susceptibility map to be produced in response to groundwater level fluctuations. The methodology has been tested on a significant rainfall episode in 2019, and the results are presented. This system is intended for local managers, which are facing with the management of landslide risk. The accuracy of the approach and the different uncertainty sources are presented, leading to some discussions about some necessary improvements of the system for a reliable Early Warning System.
Historical land cover changes of the Erebe-islands forest reserve (Hungary) and their effects on carbon cycle
Authors: Balázs Pál , Horváth Adrienn , Végh Péter , Bidló András
Published: February 2023

In our study, we analysed the long-term land cover changes and soils of the Erebe-islands forest reserve (Hungary). The historical land cover investigation is based on digitized military survey maps dating back to the 18th century and the lately finished national ecosystem basemap. Based on the analysed map series in the core area forests first appeared in the middle of the 20th century. The buffer zone was covered by water and grassland until the first half of the 20th century. Results can contribute to the investigation of interrelations between historical land use and actual soil and vegetation properties, especially carbon storage.This article was made in frame of the project TKP2021-NKTA-43 which has been implemented with the support provided by the Ministry of Innovation and Technology of Hungary (successor: Ministry of Culture and Innovation of Hungary) from the National Research, Development and Innovation Fund, financed under the TKP2021-NKTA funding scheme.
A Study On Applicability Of Flood Risk Maps For Flood Risk Assessment
Authors: Kang YuJin , Lee Hoyong , Kim Soojun , Kim Hung Soo
Published: February 2023

Regarding existing qualitative evaluations for flood risks, the researcher is to use the food risk map made by the flood risk map made by applying extreme rainfall to national, local, and small rivers. The submerged range is the same regardless of rainfall intensity. Therefore, this study prepares a flood risk map by frequency and conducted IBA (Indicator-Based Approach) flood risk assessment from 2016 to 2020 for metropolitan cities. In addition, by calculating climate change through the future flood risk index, the researcher will analyze this trend with the Mann-Kendall method. This study individually prepares a flood risk map according to rainfall intensity by calculating the design flood discharge by frequency. In this case, not only hazard but also changes in the exposure and vulnerability indexes as the area of the flood risk map changes. In the case of exposure and vulnerability, extracted and calculated flood risk map includes the population and the number of buildings, so the index of the relevant items changes according to the area of the flood risk map. This study conducts a future flood risk assessment using the climate change scenario when flood risks for future metropolitan cities can be analyzed and used to cope with environmental changes. In addition, if there is a trend towards increasing at specific rainfall observatories around metropolitan cities through trend analysis, it can be shown as evidence that the probability of rainfall by future frequency is extensively estimated given these characteristics. Using these results, a local government can make a plan to manage flood risks.
Analysis of Climate Change Mitigation and Flood Reduction Effects of Nature-based Solutions
Authors: Lee Hoyong , Kang Yujin , Kim Hung Soo , Kim Soojun , Kim Kyunghun
Published: February 2023

Due to climate change, rainfall occurs at a higher frequency than the design frequency, and flood damage has occurred in excess of the river design standard. Currently, river management in general is gray infrastructure such as embankments and weirs for irrigation and flood control. However, the river management plan through the gray infrastructure emits carbon dioxide, increasing the occurrence of extreme weather due to climate change and intensifying flood damage, causing a vicious cycle to repeat. Therefore, since the river management method by gray infrastructure cannot be adopted as a sustainable solution, the concept of Nature-based Solutions(NbS), which seeks to solve environmental and social problems through ecosystem services, is attracting attention recently. Therefore, in this study, the flood reduction effect of river management using NbS was quantitatively analyzed for the Hwang River, which is directly downstream of Hapcheon Dam. In addition, using the climate change scenarios of the IPCC 6th Assessment Report, the study tried to confirm the ability to respond to climate change through NbS. We used SSP5-8.5(Shared Socioeconomic Pathways5-8.5) and SSP2-4.5 scenarios for future precipitation, and the design flood discharge was calculated through HEC-HMS. Floodplain excavation and dyke relocation, which are included in the NbS, were applied to the flood risk area of the Huang River. As a result of analyzing the flood level of the river through the unsteady flow analysis of HEC-RAS, it was possible to confirm the effect of reducing the flood level by 5 to 7 cm for each scenario at the confluence of the Nakdong River. The results of this study can be expected to be sufficiently utilized as a basis for use as a management plan through NbS rather than the river management with grey infrastructure.
Side-effects of doing research? Potential consequences of involving non-academic actors in natural hazard research
Authors: Posch Eva
Published: February 2023

Academia is more and more under the demand to create both scientific and societally relevant research with beneficial effects for society. There is a strong consensus that the engagement of non-academic actors in research activities is associated with greater societal relevance and usability of science for society. Involving non-academic actors within natural hazards and disaster risk research has seen a rise in popularity with the advent of participatory and transdisciplinary research approaches. Particularly in countries of the Global South, the participation, engagement, or involvement of non-academic actors in research on natural hazards and disaster risk is seen as promising strategy for solving data issues, raising awareness and generating knowledge. However, besides beneficial consequences, the participation, engagement, or involvement in scientific research may also have negative side-effects for non-academic actors (e.g., causing mistrust, anxiety, or research-fatigue). Against this background, the aim of the ImSE-R project is to assess how the participation, engagement, or involvement in scientific research on natural hazards and disaster risk may have consequences – ranging from intended impacts to unintended implications and negative side-effects for non-academic actors. This contribution presents the results of a systematic review of studies on hazards and disaster risk in the Himalayan region (2000-2022) to better understand how academic actors negotiate and manage research relationships with non-academic actors in the context of natural hazards and disaster risk research. The contribution derives insights on how non-academic actors were involved in natural hazard and disaster risk research activities (actively, passively); underlying motivations and goals of academic actors for involving non-academic actors in natural hazard and disaster risk research; and perceived impacts and implications of involving non-academic actors in research. The results of the review feed into the development of a conceptual framework on research impacts and implications in the context of natural hazard and disaster risk research.
Summer jet stream response to global af-/reforestation and deforestation
Authors: Manola Iris , Coumou Dim , Luo Fei , Guo Suqi , Havermann Felix , De Hertog Steven , Lejeune Quenting , Menke Inga , Pongratz Julia , Schleussner Carl , Seneviratne Sonia , Thiery Wim
Published: February 2023

 Global-scale af-/reforestation (A/R) and deforestation substantially changes the Earth’s energy and water fluxes, thereby affecting the large-scale atmospheric circulation and thus have significant impacts on weather systems. During summer, A/R and deforestation induced changes in the soil moisture are shown to have an impact on the planetary wave response through the jet stream. Such changes might lead to high-amplitude, quasi-stationary circumglobal Rossby waves that have been associated with extreme summer heatwaves and persistent high-impact extremes. In this study we investigate how idealized global land use and land management changes can alter the boreal summer circulation with a focus on the response of the jet stream. For the analysis we conducted model experiments with three fully coupled Earth System Models (EC-EARTH, MPI-ESM and CESM). Each scenario run for 160 years from which we analyze the final 30 years.  A control run with constant current land use and land management is compared to a global A/R and a global deforestation (global cropland expansion) simulation. In order to assess clean land-atmosphere interactions, all simulations are kept with constant present-day atmospheric forcings (year 2014). We investigate the potential changes in the amplitude of the waves, the likelihood of quasi-stationary wave activity, and of summer blockings within the three different simulations, and the weather consequences that such changes lead to.
Fate and transport modelling of microbial water quality: impacts of climate change and socioeconomic development
Authors: Sokolova Ekaterina , Begion Viktor , Islam M. M. Majedul , Bondelind Mia
Published: February 2023

Anthropogenic activities in a watershed may pose human health risks due to faecal contamination of surface waters. Thus, socioeconomic development is important when predicting future microbial water quality. Moreover, climate change alters meteorological conditions, thereby affecting flow regimes as well as fate and transport of microorganisms. In this study, possible risks due to socioeconomic development and climate change were assessed for the drinking water source Lake Vomb in Sweden by means of water quality modelling. The hydrological model ArcSWAT and the hydrodynamic model MIKE 3 FM were used to simulate fate and transport of two microorganisms, i.e., Cryptosporidium and E. coli, from the watershed to the water intake. The hydrological model and the hydrodynamic model were calibrated and validated using observed data on water flow and water temperature, respectively. The water quality in the watershed and in the lake was simulated for a baseline scenario and for future scenarios in the second half of this century. The future scenarios were formulated based on Representative Concentration Pathways (RCPs) and Shared Socioeconomic Pathways (SSPs). The modelling results illustrated the effects of climate changes and of socioeconomic development. The results were also interpreted in the context of infection risks to drinking water consumers using quantitative microbial risk assessment. This study clearly illustrates that socioeconomic development is important to include when investigating future microbial water quality.
The potential of probabilistic moment-tensor inversions for the characterization of geothermal reservoirs in urban environments
Authors: Draganov Deyan , Naranjo David , Polychronopoulou Katerina , Weemstra Cornelis
Published: February 2023

Geothermal energy is a cleaner and more sustainable source of power, which plays a key role in the transition to a low-carbon economy. Sustainable and safe exploitation of geothermal resources, however, depends on our ability to understand and manage the associated seismic risks. In 2018, Nature's Heat geothermal project began operations in Kwintsheul, Netherlands, aiming to supply heat to 64 hectares of greenhouses. Between July and October 2019, a temporary seismic array was installed to monitor for possible seismic activity at the site. Microseismic moment-tensor inversion is a valuable tool for understanding the mechanics and structure of geothermal reservoirs, and for optimizing their exploitation. It can be challenging, though, to apply this technique when there are high levels of ambient seismic noise, as is often the case in geothermal operations in densely populated areas. In this study, we evaluate the feasibility of inverting the centroid moment tensor of microseismic events in Kwintsheul, using probabilistic moment-tensor inversions. We first test the probabilistic inversion using synthetic recordings of ambient seismic noise, after which we apply the technique to the low-magnitude (Md=0.16) event recorded on July 14, 2019. Our results give insight into the challenges and limitations of applying moment-tensor inversion to low-magnitude events in the context of geothermal operations in the Netherlands.
Increasing probability of extreme records in heavy precipitation
Authors: de Vries Iris , Sippel Sebastian , Fischer Erich , Zeder Joel , Humphrey Vincent , Knutti Reto
Published: February 2023

It comes as no surprise that the future holds record-breaking weather and climate events. As global warming continues, temperature records will continue to be broken. Also heavy precipitation records are likely to be broken due to the increased water holding capacity of the atmosphere, in combination with changing atmospheric stability and circulation patterns. Improved estimates on the range of possible record-breaking precipitation events – now and in the future – are a first step to inform adequate adaptation policies for heavy precipitation. Of particular interest are events that break records by large margins – record-shattering events –, since these are likely to incur most damage and losses. In order to improve estimates of record shattering precipitation events in the present and future climate we use initial condition large ensemble simulation data (CESM2, SSP370) and statistical models. We evaluate record-shattering events in Rx1d (day with most precipitation per chosen time period (year or season)). In a stationary climate, the probability of Rx1d record-breaking is known to decrease with the number of data points since the start of measurements (inversely proportional). We find, however, that in our nonstationary climate, the decay in Rx1d record breaking and shattering probability is slowed down and even reversed in most world regions. Regional changes in record shattering probability are attributable to a changing underlying probability distribution of Rx1d, which also is region specific. We elucidate the contributions of changes in mean (distribution shift), and in variability (distribution widening/narrowing) to increasing record shattering probability by using a statistical model to create counterfactual realities representative of the regions of interest.We focus on regions of a size relevant for national and cross-border policy that show differently driven changes in record shattering precipitation probabilities. For example, the annual probability of a record shattering precipitation event somewhere in the Benelux-Germany region which was hit by severe floods in summer 2021 increases from ~2% now to ~4.5% at the end of the century in CESM2. This increase results from a non-linear interaction between mean and variability increases, and is primarily driven by increasing variability. At lower latitudes, for example in Central America, the effect of variability is even stronger, where we find increasing record shattering probability despite a negative long-term trend in Rx1d levels.Very unlikely events are, paradoxically, arguably the most important to know about, since their unimaginability often means that critical infrastructure is not sized to withstand these events. Our results may thus prove invaluable for regional policy. 
Seasonal forecasting of subsurface marine heat waves
Authors: McAdam Ronan , Masina Simona , Gualdi Silvio
Published: February 2023

Marine heat waves (MHWs) cause devastating damage to ecosystems and ocean services, with effects being identified mostly below the ocean surface. Current forecasting efforts, however, focus only on metrics based on sea surface temperature. To create a more user-relevant detection system, it is necessary to provide forecasts of subsurface events. Here, we demonstrate the feasibility of seasonal forecasting of subsurface MHWs by using ocean heat content, a more relevant indicator than surface temperature for marine stakeholders. We validate summer MHW indicators in a fully-coupled seasonal forecast system against a global ocean reanalysis and satellite data. Our main result is that subsurface summer MHWs are predicted with greater skill than surface MHWs across much of the global ocean. Sub-surface MHWs are typically longer-lasting than surface events, rendering them easier targets for forecasting systems. Despite the long-lasting nature of subsurface MHWs, we also show that the dynamical forecast system used here typically outperforms a MHW-persistence model, indicating the capability for capturing the onset and decay of MHWs. Lastly, we highlight the role of warming oceans in MHW detection skill, by removing linear trends. This work highlights the need for a wider appreciation of subsurface ocean phenomena and the increased uptake of seasonal forecasting indicators by marine stakeholders such as marine protected areas and fisheries.
The influence of the carbonate pump on the ocean carbon cycle - natural air-sea carbon fluxes, inter-hemispheric carbon transport and anthropogenic perturbations
Authors: Planchat Alban , Bopp Laurent , Kwiatkowski Lester
Published: February 2023

To what extent does the representation of the carbonate pump and its evolution in a transient climate influence the ocean carbon cycle? The carbonate pump, the amplitude of which can be estimated through the CaCO3 export flux, is sometimes qualified as a counter-pump. Indeed, by inducing an imbalance between total alkalinity (Alk) and dissolved inorganic carbon (DIC) in the surface ocean, calcification induces relative degassing and acidification. However, it also drives vertical gradients of Alk and DIC in the ocean in response to CaCO3 dissolution at depth. Using equilibrium simulations of the NEMO-PISCES marine biogeochemical model, we investigate the influence of the carbonate pump on natural air-sea carbon fluxes and inter-hemispheric carbon transport within the ocean. We further show that despite diverse twenty-first century changes in the carbonate pump in CMIP6 models, its impact on the projected upper ocean carbon cycle is minimal compared to other drivers. Interpreting our results, we rely on the pair of conservative variables Alk and DIC, central to the representation of the ocean carbon cycle in models. In particular, we show that the usefulness of the classically represented Alk/DIC diagram can be extended to derive quantitative and comparative visual information on the processes driving the upper ocean carbon cycle.
EUMETNET Nowcasting Programme
Authors: Schmid Franziska , Sivle Anders , Agersten Solfrid , Simon André , Atencia Aitor
Published: February 2023

One major task of the National Meteorological and Hydrological Services (NMHS) is the provision of consistent and integrated forecasting products from minutes to several days ahead (seamless forecasting). The former EUMETNET (European Meteorological Services’ Network) project ASIST (Application oriented analysis and very short-range forecast environment) which started in 2015 focused on the nowcasting and very short range forecasting. Then, it was extended to the EUMETNET Nowcasting Programme (E-NWC) which started in 2019 and will last until the end of 2023 with focus on nowcasting and also on seamless prediction.
In this presentation, the main objectives of the E-NWC Programme will be introduced. E-NWC supports NMHS in sharing expertise, experiences and best practices for developing and implementing nowcasting, very short-range forecasting and seamless prediction systems. Key activities lie in the exchange of information and experiences with the users during e.g. the every two years European Nowcasting Conference and the strong cooperation with the World Meteorological Organization (WMO) and EUMETSAT, and in summarizing the relevant findings in project reports and joint peer-reviewed papers. Highlights of this contribution comprehend a few results from studies and surveys carried out recently.
Machine Learning models for probabilistic rainfall nowcasting applied to a case study in Italy: the extreme rainfall event on 26 November 2022 over Casamicciola town, Ischia Island.
Authors: Pirone Dina , Del Giudice Giuseppe , Pianese Domenico
Published: February 2023

On 26 November 2022, an extreme rainfall event occurred over Ischia Island (Italy). It triggered a mudflow that swept over Casamicciola Terme town and caused 12 victims. Based on available rainfall data from 4 rain-gauge stations over the island, the precipitation values registered during the event were higher than the annual maxima values of the previous 15 years. With regards to 1 and 24 hours, the rain-gauge stations measured values between 40.6 and 57.6 mm, and between 145.4 and 176.8 mm, respectively. Since one of the main challenges during these phenomena is predicting rainfall sufficiently in advance in order to allow water managers to take action (issue warnings or real-time control), this study investigates how much time before the peak - or threshold exceedance - a machine learning model is able to capture the peak - or threshold exceedance. A model that predicts rainfall intervals and the corresponding probability of occurrence for lead times from 10 minutes to 6 hours is proposed. The model employs cumulative rainfall depths from recording stations in an area of 50 km radius from the Ischia Island as inputs for a Feed Forward Neural Network to nowcast rainfall in the 4 rain-gauges over the study area. Based on almost 400 rain events observed during years 2009-2022, 24 machine learning models were independently trained for each rain-gauge and each of the 6 lead-times - 10, 30, 60, 120, 180 and 360 minutes. The performance of each model was evaluated and compared using different metrics, both continuous (RMSE and MAE) and categorical (POD and FAR). In addition, the Eulerian Persistence (EP) was considered as a benchmark model. The rainfall nowcasts showed encouraging results. Even though for convective rain events the potential lead-time is short, the models produced consistent nowcasts for lead-times up to 2 hours. With probabilities of almost 90%, the thresholds exceedance was forecasted up to 1 hour before. As expected, predictive accuracy and probabilities gradually decreased as the lead-time increased, according to physically based models. Moreover, the proposed models outperformed the benchmark EP for all the lead-times and performance criteria. Results confirmed that the use of cumulative rainfall depths for precipitation nowcasting made this approach a promising tool for nowcasting purposes, and his flexibility and conceptual simplicity resulted in a rapid, easily replicable and convenient nowcasting approach. To conclude, the proposed models enhanced a first identification of critical thresholds, which should be further analysed in order to achieve a better, complementary understanding of the occurring phenomenon. Keywords: Precipitation nowcasting; Multi-step predictions; Rain-gauge measurements; Pattern recognition; Feed forward neural networks; Cumulative rainfall fields.
Lithospheric modeling in Iran and the Arabian Peninsula from gravity data including seismic tomographic data: first results.
Authors: Maurizio Gerardo , Braitenberg Carla , Sampietro Daniele , Capponi Martina
Published: February 2023

In this presentation we want show our lithosphere density model of a Middle East area encompassing Iran and the Arabian Peninsula, realized through a Bayesian inversion applied to an optimized density model. The starting model used for the inversion was obtained converting seismic velocities interpolated from local and global tomographies and converted in densities using a simplified version of the Brocher’s relation for velocity-to-density conversion, recalculating new coefficients for the relation. This optimization was realized following a Least Squares method, inverting global gravity field data. The model was divided into five parts: water, sediment, crust, mantle, and a separate crustal layer was defined in the Red Sea zone. Specifically, the Moho depth was obtained using the vertical velocity gradient method as presented in Tadiello and Braitenberg (2021), except for the southeastern zone along the Red Sea suture, which had strong velocity anomalies at the surface, and we relied on those to model a faster intrusive body within the crust, while estimation of the density distribution in the mantle was obtained using Perple_X software.  We present the final density model, resulting from the inversion, and discuss it in terms of intra-crustal densification and relation to surface magmatic outcrops, finding that correlations can be identified. These demonstrate the presence of deep-seated crustal density variations which relate to geological provinces identified from surface investigations. A further point to discuss is the rheological properties obtainable from the joint velocity and density model and the relation to the inhomogeneous distribution of seismicity.
A strategy to deal with climate change: Intercropping system has attracted increasing interest.
Authors: Ma Longshuai
Published: February 2023

Rainfed agriculture is conducted on 80% of the world's arable land and provides 60% of the world's food, therefore playing an important role in ensuring food security for a growing population. Climate change impacts are predicted to be harmful for rainfed agriculture all over the world, which will face future yield reductions of up to 30%, so more attention should be given to the efficient use of agricultural water in agricultural production, especially under rainfed conditions. Intercropping is a traditional sustainable planting system having advantages of increased production and improved yield stability, which is widely valued and has attracted increasing interest as a strategy to deal with climate change. Clarify the water consumption process of the intercropping system, especially the complementary and competition mechanism of soil water between species, is necessary for optimizing the field management and improving the water use efficiency of the intercropping system. The Loess Plateau is a typical rainfed farming area in northern China, the limitation of water resources and soil erosion are two major problems for efficient agricultural production. Therefore, we focuses on water consumption process of the intercropping system on the Loess Plateau, and the research results can provide theoretical support for the healthy and sustainable development of agriculture in rainfed area.
Assessing urban water insecurity under access inequality - coupled human-natural systems analyses in the Upper Bhima Basin, India
Authors: Klassert Christian , Wang Ankun , Jain Figueroa Anjuli , Zhu Yuanzao , Karutz Raphael , Zozmann Heinrich , Klauer Bernd , Gawel Erik , Gorelick Steven
Published: February 2023

Adapting to growing urban water scarcity requires accurate assessments of present and future water security challenges. An estimated 1 billion people live in cities with intermittent public water supply, often resulting in highly unequal access to water. Under these conditions, households with below-average water access are most exposed to water insecurity. As a result, the full extent of water insecurity could substantially exceed the impacts identified by aggregate water security metrics. Here, we extend an existing coupled human and natural system model of the entire water sector in the Indian Upper Bhima basin, in order to analyze the degree to which water access inequality exacerbates urban water insecurity. The model integrates hydrologic modeling with urban water allocation institutions and water user agents, using data from a quantitative survey of almost 2,000 households in and around Pune, remote sensing data, as well as village-level census and water supply data. We use the model to assess water security impacts under historical and future droughts and various levels of supply augmentation. We find that a large share of households falls below critical water security thresholds before impacts are detected by aggregate metrics. While an unequal water distribution prevails, supply augmentation projects require several times the scale to meet given per capita water supply targets across the population than they would under a more equitable distribution. The findings demonstrate the extent to which current assessments of future urban water insecurity can underestimate the challenges ahead.
Settings of cryogenic cave carbonate formation
Authors: Dublyansky Yuri , Spötl Christoph , Koltai Gabriella
Published: February 2023

Cryogenic cave carbonates (CCCs) and, more generally, cryogenic cave minerals, form by solute rejection mechanisms when water enters and freezes in caves, or parts of caves, at temperatures below the freezing point. Negative temperatures may occur in caves in conjunction with climatic factors ranging from seasonal (e.g., sag-type cave entrances or ventilated parts of caves) to millennial (development of permafrost in karst massifs) timescales. When using CCCs for paleoclimate reconstructions, it is important to understand the environment in which they were formed.Conventionally, two ‘end-members’ of cave microclimate settings are distinguished, in which water freezes either rapidly or slowly. These settings are responsible for the formation of fine-grained (typical sizes < 1 mm) vs. coarse-grained CCC (> 1 mm; the largest individual CCC encountered so far weighs 123 g). Besides difference in size, these two types of CCC show distinct stable isotope (O and C) patterns, currently considered as the most reliable (if not the only) feature that allows discriminating between the two types. The slowly formed CCCs that are coarse grained and show characteristic trends of 18O depletion and 13C enrichment (relative to non-cryogenic carbonates from the same cave) are thought to represent markers of past permafrost.   Although both defining features, size and stable isotopic properties of CCCs, are controlled by the rate of freezing, the control may have different characteristic times. The rate of freezing is controlled by: (1) the overcooling of the site; (2) the amount of water entering the cave; and (3) the regime of water inflow (semi-continuous or pulse-like). Large amounts of water (even of low temperature) entering a cave entrain large amounts of heat that need to be dissipated before freezing commences. Further, the release of latent heat maintains the temperature of the freezing water body at 0 °C for the duration of the freezing process. Slow freezing leads to progressive depletion of the residual water in 18O and, as a result, CCCs are also increasingly depleted in 18O. We observed depletions of several permil in the time span of a few days in laboratory experiments.  In caves located in relatively cold environments (e.g., Alpine or high-latitude caves) seasonal freezing conditions can be created by low-intensity influx of outside cold air into sections of caves located in already relatively cold rock. In such zones a small overcooling may be maintained for a sufficiently long time, producing CCCs with isotope properties mimicking (partly or entirely) those of CCCs forming in static settings of “true” permafrost.
Observation-Consistent Nonlinear Ice Melt Contribution to Sea Level Rise and its Implications for Sea-Level Projections
Authors: Avrutin Sandy , Goodwin Philip , Haigh Ivan D , Nicholls Robert
Published: February 2023

Sea level rise is a major result of climate change that threatens coastal communities and has the potential to incur significant economic damage. Projecting sea level rise as temperatures rise is therefore crucial for policy and decision-making.The two modelling methods currently used to project future sea level change are process-based and semi-empirical. Process-based models rely on combining outputs from coupled atmosphere/ocean models for each component of sea level rise. Semi-empirical models calculate sea level as an integrated response to either warming or radiative forcing, using parameters constrained from past observations.Historically, there is disagreement in sea-level projections between different modelling methods. One source of the discrepancies is uncertainty in land ice response to warming; although nonlinearities exist within processes affecting this response, most existing semi-empirical models treat the relationship between warming and ice-melt as linear.Non-linear ice melt processes may have not yet affected the observational record (such as tipping points as future warming crosses some threshold) or may have already occurred (such as non-linear effects that apply across all levels of warming, or for which the threshold has already been passed). Here, we examine the effect on semi-empirical projections of sea level rise of nonlinearities in ice melt that have already affected the observed sea level record, by adding a nonlinear term to the relationship between warming and the rate of sea level rise within a large ensemble of historically constrained efficient earth systems model simulations.Projections reach a median sea level rise of 1.3m by 2300 following SSP245, and 2.6m by 2300 following SSP585. Results suggest that nonlinear interactions can be sub-linear, super-linear or 0, with a mainly symmetrical distribution. This includes high-impact, low-probability super-linear interactions that lead to significantly larger high-end sea level rise projections than when nonlinear interactions are not included. It is key to note that nonlinear interactions that have not yet occurred but that may occur in the future, are not considered – these will lead to an increased projection of sea level rise.