bluuebunny/crossref_metadata_2025 huggingface dataset:
Spatial variations of slip and creep rates along the Dead Sea Fault and the Carmel-Gilboa Fault System
Authors: Hamiel Yariv , Piatibratova Oksana
Published: March 2022

Crustal deformation and seismic activity in the Levant is mainly related to the interplate Dead Sea Fault (DSF) and the intraplate Carmel-Gilboa Fault System (CGFS). In this study we analyze the interseismic deformation along these fault systems using 23 years of GPS measurements obtained from 209 campaign and 60 continuous stations. This GPS dataset is the longest record and the densest dataset for the DSF and the Levant region. We use this dataset to investigate the spatial variations of slip and creep rates along the southern and central sections of the DSF and the CGFS. Our inversion model results indicate that part of the tectonic motion is transferred from the DSF to the CGFS. We find that the left-lateral strike-slip motion along the DSF decreases in a rate of 0.9±0.4 mm/yr, from 4.8±0.3 mm/yr south to the intersection with the CGFS, to 3.9±0.4 mm/yr north to this intersection. Along the CGFS the left-lateral strike-slip motion ranges between ~0.3-0.5 mm/yr and the extension rate between ~0.6-0.7 mm/yr, indicating a total slip rate vector of 0.8±0.4 mm/yr in the DSF direction, in agreement with the reduction of slip rate along the DSF near the intersection with the CGFS. Shallow creep is found along the southern and central sections of the Dead Sea basin and the northern Jordan Valley section of the DSF, with creep rates of 3.4±0.4 and 2.3±0.4 mm/yr, respectively. These creeping sections were identified as areas with thick salt layers at the shallow subsurface. We suggest that shallow creep behavior along the DSF is govern by the presence and mechanical properties of the salt layers, which probably allows plastic deformation and the transition to velocity strengthening at the shallow subsurface and promotes creep.
Terraces response to different uplift modes at subduction margins: a forward modelling approach
Authors: Crosetto Silvia , de Montserrat Albert , Oncken Onno
Published: March 2022

Marine terraces are preserved along the coast when their uplift rate overcomes the rate of sea level increase. Generally, if the relative sea level history is known, elevation and age of marine terraces can be used to quantify the average uplift rate.

At subduction margins, large-scale topography of the fore-arc is the result of complex subduction mechanisms. The existence of uplifted marine terraces along fore-arc coastal areas indicates that the topography is subject to long-term permanent uplift. However, it is yet not known when this permanent uplift is accommodated. Geodetic observations show that, of the total deformation occurring during the megathrust earthquake cycle, only a minimal part (<10-20%) is translated into permanent vertical deformation of the topography. Additionally, particularly high uplift rates (~1 mm/yr) of fore-arcs observed geodetically, or geologically using uplifted marine terraces, suggest the existence of uplift transients or pulses that seem to reflect earthquake clustering on upper plate faults lasting 10 to 100 kyrs, while underplating cycles deduced from field observations and derived from numerical models occur at time scales from 0.5 to 6 Myrs.

We use numerical models to investigate whether different uplift styles are reflected in the geometry of the marine terraces sequences. In particular, we aim at spotting the occurrence of diagnostic patterns representative of different uplift ‘modes’: constant uplift rate, uplift by earthquake pulses (permanent uplift only), or uplift resulting from interseismic and coseismic vertical displacements. The results show that the variability of the terrace staircase morphology subject to different uplift modes increases with the earthquake recurrence time. Preliminary comparison with natural case studies displaying an analogue variability confirms our argument.
Present and future influence of ocean heat transport on winter Arctic sea-ice variability
Authors: Dörr Jakob , Årthun Marius , Eldevik Tor
Published: March 2022

The recent retreat of Arctic sea ice area is overlaid by strong internal variability on all timescales. In winter, the variability is currently dominated by the Barents Sea, where it has been primarily driven by variable ocean heat transport from the Atlantic. As the loss of winter Arctic sea ice is projected to accelerate and the sea ice edge retreats deeper into the Arctic Ocean, other regions will see increased sea-ice variability. The question thus arises how the influence of the ocean heat transport will change. To answer this question, we analyze and contrast the present and future regional impact of ocean heat transport on the winter Arctic sea ice cover using a combination of observations and simulations from several single model large ensembles from CMIP5 and CMIP6. For the recent past we find a strong influence of the heat transport through the Barents Sea and the Bering Strait on the sea ice cover on the Pacific and Atlantic side of the Arctic Ocean, respectively. There is strong model agreement for an expanding influence of ocean heat transport through these two gateways for high and low warming scenarios. This highlights the future importance of the Pacific and Atlantic water inflows.
The impact of mesoscale variability on northward volume transport in the Irminger Sea
Authors: Fried Nora , Katsman Caroline A. , de Jong M. Femke
Published: March 2022

The Irminger Current (IC) is known to be an important contributor to the northward volume transport associated with the Atlantic Meridional Overturning Circulation (AMOC). The IC has a two-core structure with surface intensified velocities and transports warm and saline waters originating from the North Atlantic Current further north. The strength of the subpolar AMOC is continuously measured by the Overturning in the Subpolar North Atlantic Program (OSNAP) since 2014. Recent results highlight that most of the overturning in density space occurs in the array east of Greenland, in the Irminger and Iceland Basins. In previous work we looked into the transport variability of the IC on decadal to interannual time scales and could identify long-term trend related to basin-wide density changes which have the potential to impact AMOC variability. However, the impact of mesoscale variability on northward transport variability in the Irminger Sea has not been studied yet.

In this study, we explore the mesoscale variability in the IC and its impact on northward transport variability.

Previous studies showed that the western flank of the Reykjanes Ridge, where the IC is located, is a region of enhanced eddy kinetic energy. We used high resolution mooring data from 2014 – 2020 from the IC mooring array to investigate its transport variability. The mean volume transport obtained for the IC is 10.4 Sv but it strongly varies on time scales from days to months (std. dev. of 4.3 Sv). The mooring data reveals a seasonal cycle in the eddy kinetic energy with the strongest activity in winter. However, this does not coincide with a seasonal cycle in volume transport. We found the strongest EKE in the western core of the IC. In 2019, an exceptional 6-month intensification of the IC led to exceptionally strong volume transport of the IC of 19.9 Sv in August. Using sea level anomaly maps from satellite altimetry, the intensification was attributed to the presence of a mesoscale eddy in the vicinity of the moorings.  At this time, altimetry shows an anticyclone lingering next to a cyclone in the mooring array, which intensified northward velocities within the IC. We thus conclude that mesoscale variability can directly impact both the transport and the variability of the IC.

Considering the potential importance of mesoscale variability along the Reykjanes Ridge, further research will focus on estimating the mean properties of the eddies, their formation region and their faith using a high-resolution model.
Analysis of turbulence from EDR reports and ERA5 in the UTLS over the North Atlantic during winter in a tropopause-relative framework
Authors: Kaluza Thorsten , Hoor Peter , Kunkel Daniel
Published: March 2022

The tropopause is often concieved as a quasi-two-dimensional surface which marks the border between the troposphere to the stratosphere. The transition of chemical trace gas characteristics along with the ambiguity of different tropopause definitions however gives rise to a perception of the tropopause as a three-dimensional transition layer. The transition of the chemical composition is associated with the occurrence of distinct dynamical processes at the interface between troposphere and stratosphere. These processes foster cross-tropopause exchange and mixing around the tropopause which in turn is thought to create the chemical transition across the tropopause. A variety of diabatic processes have been proposed and analysed in this context, i.e., convective overshooting and injection of tropospheric air into the stratosphere, radiatively induced potential vorticity modification along with a modulation of the tropopause altitude and stratosphere-troposphere-exchange, and the occurrence of flow instabilities and turbulence. The overall significance of individual processes concerning the formation and maintenance of the all year existing and chemically defined extratropical transition layer remains an open research question.

This study aims to shed new light onto this question. For this an analysis is presented over the time period of two winter seasons. The goal is to obtain a tropopause relative vertical distribution of turbulence across the tropopause over the North Atlantic. A total of 1.5 million automated EDR reports from commercial aircrafts have been analysed to identify the occurrence of turbulence in the UTLS. This data is complemented by ERA5 reanalysis data to put the EDR reports into the tropopause relative coordinate system. From ERA5 several other turbulence indicators and diagnostics are calculated and will be presented to ultimately explain the vertical extent of the transition layer around the tropopause.
Application of the Shields diagram for evaluating critical shear stress for vegetated flows
Authors: Lu Yesheng , Cheng Nian-Sheng , Wei Maoxing
Published: March 2022

The well-known Shields diagram is developed for unvegetated open channel flows to describe incipient sediment motion by means of critical bed shear stress. Due to difficulties in estimating the bed shear stress in vegetated flows, it is not clear whether the Shields diagram is applicable in the presence of vegetation. By applying the phenomenological theory of turbulence, a new method to evaluate the bed shear stress in vegetated flows is proposed in this study. With this method, the critical bed shear stress subject to vegetated flows is calculated using the published data. The result shows that the calculated critical shear stresses are consistent with the Shields diagram.
Performance analysis of deep borehole heat exchangers in the Pannonian Basin
Authors: Békési Eszter , Szekszárdi Adrienn , Porkoláb Kristóf , Tóth Krisztina , Gáti Mátyás
Published: March 2022

Primarily due to the lack of production of geothermal fluids from subsurface aquifers, closed-loop geothermal systems are promising solutions for sustainable and cost-effective exploitation of geothermal energy. Compared to conventional or unconventional open-hole geothermal systems, the performance of deep borehole heat exchangers (DBHE) are relatively low. However, DBHEs may become favorable choices in certain areas due to the significantly lower exploration risks and their potential to be constructed in abandoned deep boreholes. We investigate the thermal performance of DBHEs in the Pannonian basin, exhibiting one of the hottest regions within Europe, with an average geothermal gradient of ~45 °C/km. We analyze the effect of various geological and technical parameters on the resulting outflow temperatures and output thermal powers in order to find the optimal sets of parameters for the long-term sustainable operation of DBHEs in the Pannonian basin. We approximate the performance of coaxial DBHEs through finite-element numerical modelling using the FEFLOW software. We construct the reference model in a geological environment representative for the Great Hungarian Plain based on information from well logs and literature data. The most important geological parameters we consider in the parameter tests include the geothermal gradient, lithologies, and the presence and significance of natural groundwater flows in the surroundings of the DBHE. Furthermore, we test the influence of various technical and operational parameters such as the type of working fluids, the depth of the DBHE, the thermal conductivity of the tubes, and the temperature and flow rate of the injected fluids. We predict the thermal output for the period of 10 years in order to find realistic parameter combinations that can facilitate sustainable production and reveal the most critical parameters that influence system performance in Pannonian basin settings. These results can help estimating system performance in case of actual geothermal projects and can be used as input parameters for economic calculations.
Natural and anthropogenic excitation sources for seismic and infrasonic on-site calibration
Authors: Schwardt Michaela , Gaebler Peter , Hupe Patrick , Pilger Christoph
Published: March 2022

In the low-frequency range down to 0.1 Hz suitable and reliable calibration procedures, which include traceability to SI, for seismic and infrasonic sensors are currently missing. Although many events occur whose evaluation is of global interest, much of the low frequency range relevant to these applications is not yet covered by primary measurement standards. A laboratory calibration of sensors results in an interruption of the measurements, just as the use of built-in calibration coils disturbs the measurements. Therefore, with regard to the design goal of the Comprehensive Nuclear-Test-Ban Treaty Organization’s (CTBTO) International Monitoring System (IMS), which requires the stations to be operational 100 % of the time, on-site calibration during operation with a reference sensor previously calibrated in the laboratory is of special interest.

We have assembled sets of both natural and anthropogenic sources of seismic, infrasonic, and hydroacoustic waves with respect to their individual signal characteristics and, as part of the joint research project "Metrology for low-frequency sound and vibration - 19ENV03 Infra-AUV", evaluated their potential use as excitation signals for on-site calibration regarding aspects that include knowledge about the source characteristics, the frequency content, reproducible and stable properties as well as the applicability in terms of cost-benefit. With the aid of these sources, procedures are to be established which will allow permanent on-site calibration without any interruptions of the recordings, thereby improving data quality and consequently the identification of treaty-relevant events.

In that context, man-made controlled sources such as drop weights or loudspeakers exhibit properties that make them an interesting source signal for the calibration of seismometers and infrasound sensors. Among the natural sources, earthquake generated signals in particular stand out because of their highly suitable signal and spectral properties. In addition, microbaroms and microseisms also play an important role for calibration, since they cover the lowest frequency range of interest. In particular, we focus here on sources that may generate both seismic and infrasonic signals. By means of a joint review of the waves’ sources in the solid earth and the atmosphere, parallels and differences are highlighted. Preliminary comparisons performed with IMS stations PS19 and IS26 in Germany show that the frequency response of different excitation sources can be determined using spectral methods and correlation analyses.
Flank instability at Mount Etna: new insights from seafloor deformation monitoring
Authors: Urlaub Morelia , Petersen Florian , Bonforte Alessandro , Gross Felix , Kopp Heidrun
Published: March 2022

Coastal and ocean island volcanoes are renowned for having unstable flanks, which expresses as slow seawards flank sliding observable by geodetic techniques and/or catastrophic sector collapses. A large section of these unstable flanks is often below sea level, where information on the volcanotectonic structure and, in particular, ground deformation are limited. Consequently, kinematic models that attempt to explain measured onshore ground deformation associated to flank instability are poorly constrained in the offshore area. This is also the case for Mount Etna’s unstable south-eastern flank that slides seawards at rates of 2-3 cm/yr. Displacements associated to flank movement, observed onshore by geodetic and remote sensing techniques, show maximum values at the coast and kinematic models consistently predict even larger movements seawards of the coast. Our seafloor geodetic measurements between 2016 and 2018 confirmed that offshore flank slip is equal or slightly larger compared to onshore slip. The main displacement was released during one slow slip event. Here, we present new data from a second deployment of the seafloor geodetic network in the same location with the same direct-path acoustic ranging technique and a modified network design. The measurements allow reconstructing relative seafloor displacement within the network at sub-centimetre precision, from September 2020 until November 2021. The preliminary results indicate a possible eastward sliding of the flank, although the overall slip of <1 cm is close to the limit of resolution. Flank slip is continuous over the observation period. With our seafloor geodetic network, we are able to record different styles of fault slip and deformation rates. Ongoing long-term monitoring will show how these styles of deformation interact, and which type of flank movement is dominant in the offshore sector.
MOVIDA: a procedure for flood damage assessment and mapping at the river district scale
Authors: Molinari Daniela , Ballio Francesco ,   MOVIDA group
Published: March 2022

The European Floods Directive (2007/60/EC) requires that Member States develop flood hazard and risk maps, to be used as the information basis for the development of Flood Risk Management Plans (FRMPs), and to update them every 6 years. To support such a process, the Po River District Authority signed in May 2020 an agreement with 20 Italian Universities and the Italian National Research Council (CNR) with the aim of transferring the state of the art about hydrology (including climate change), hydraulics and damage modelling into the production of the new maps, to be delivered by December 2021. This contribution describes the results obtained by the damage modelling group, composed by 8 universities and the CNR, within the project MOVIDA (MOdello per la Valutazione Integrata del Danno Alluvionale – Model for integrated evaluation of flood damage).
The objective of the project was to provide an Information System able to perform an analytical evaluation and mapping of expected damage, overcoming the limitations of present maps where the evaluation of risk remains highly qualitative and subjective. First, proper exposure and damage assessment tools were identified, for all the categories of exposed elements included in the Directive: population, infrastructures, economic activities (classified as: residential buildings, commercial and industrial activities, and agricultural activities), environmental and cultural heritage, and na-tech sites. These tools address specific requirements: (i) being valid/applicable for the whole District, (ii) being based on standardised and institutional data, available at national level, (iii) being calibrated (and possibly validated) in the Italian context. Second, the dedicated open-source Geographic Information System ISYDE (open-source Information SYstem for Damage Estimation) was developed to support technicians in the implementation of the proposed tools and in the visualisation and processing of damage results. Finally, ISYDE was transferred to Regional Authorities for flood damage evaluation and mapping to all areas at significant risk in the Po District.
Results of damage assessment are collected in dedicated sheets (one for each area) and are presented by means of tables, graphs, and maps, in order to provide both the overall expected damage in a specific area as well as its spatial distribution, for all the five categories of exposed elements. The new developed maps represent a significant improvement with respect to the previous ones, supporting the Cost Benefit Analysis (CBA) of mitigation measures to be defined in FRMPs. Indeed, they enable the identification and localization of typological and spatial hotspots within a single area as well as the comparison among different scenarios, in terms of CBAs.
The 2018-2020 multi-year drought sets a new benchmark in Europe
Authors: Rakovec Oldrich , Samaniego Luis , Hari Vittal , Markonis Yannis , Moravec Vojtech , Thober Stephan , Hanel Martin , Kumar Rohini
Published: March 2022

During the period 2018-2020, Europe experienced a series of hot and dry weather conditions with significant socioeconomic and environmental consequences. Yet, the extremity of these multi-year dry conditions is not recognized. Here, we provide a comprehensive spatio-temporal assessment of the drought hazard over Europe by benchmarking past exceptional events during the period from 1766-2020. We identified the 2018-20 drought event as a new benchmark having an unprecedented intensity that persisted for more than two years, exhibiting a mean areal coverage of 35.6% and an average duration of 12.2 months. What makes this event truly exceptional compared with past events is its near-surface air temperature anomaly reaching +2.8 K, which constitutes further evidence that the ongoing global warming is exacerbating present drought events. Our analysis shows that exceptional agricultural droughts enhanced by record-breaking near-surface air temperature anomalies have a significant impact (decline) on major crop yields (wheat, grain maize, and barley) across the European countries.  Furthermore, future events based on climate model simulations (CMIP5) suggest that Europe should be prepared for events of comparable intensity as the 2018-2020 event but with durations longer than any of those experienced in the last 250 years. Soil moisture drought projections synthesized in this study, even under a moderate emission scenario, indicate that decision-makers in Europe should be prepared for drought events of comparable intensity in future. Thus, the 2018--20 drought event could be considered as a wake-up call on agricultural policies. In this study, we compared and contrasted this event with earlier events of similar magnitudes and showed the role of increasing temperature rises. 

DOI of dataset: https://zenodo.org/record/5801249

Reference: 

Rakovec, O., Samaniego, L., Hari, V., Markonis, Y., Moravec, V., Thober, S., Hanel, M., Kumar, R. (2022). The 2018-20 multi-year drought sets a new benchmark in Europe. Under Review, resubmitted version

 
An analysis of robustness, sampling variation and performances of landslide triggering thresholds determined by different approaches
Authors: Peres David J. , Cancelliere Antonino
Published: March 2022

Rainfall intensity-duration landslide-triggering thresholds have been proposed as a possible component for the implementation of territorial landslide early warning systems. Given a set of rainfall and landslide data, three approaches can be distinguished to determine thresholds: (i) methods based on triggering events only, (ii) methods based on the non-triggering events only, and (iii) methods based on both type of rainfall events. The aim of the present research is to compare these three possible approaches based on statistical criteria: robustness, sampling variation, and performance. This comparison can provide an insight on which of the three approaches is more appropriate based on the dataset that happens to be available for the area of interest.

We address these aspects by setting up a virtual simulation framework combining a stochastic rainfall model with a hydrological and slope stability model, which allows to make repeated experiments and to simulate different uncertainty conditions.

Our analysis shows that methods based on triggering rainfall only can be the worst with respect to the three investigated statistical properties. Methods based on both triggering and non-triggering rainfall have the highest performances in terms of the ROC true skill statistic; they are also robust, but still require a quite large sample to sufficiently limit the sampling variation of the threshold parameters. On the other side, methods based on non-triggering rainfall only, which are mostly overlooked up, are characterized by good robustness and low sampling variation. It can also be shown that in realistic scenarios their performances can be acceptable and even higher than thresholds derived from triggering events only. Indeed, the use of triggering rainfall only, a common practice in the past literature, yields to thresholds with the worse statistical properties, except when there is a clear separation between triggering and non-triggering events.

Based on these results, it can be stated that methods based on non-triggering rainfall only deserve wider attention, as they have also the practical advantage that can be in principle used where limited information on landslide occurrence is available. The fact that relatively large samples (about 200 landslides events) are needed for a sufficiently precise estimation of threshold parameters when using triggering rainfall, provides a possible insight on the level of uncertainty of thresholds proposed in the past literature.

 
Drivers of the air-sea CO2 flux variability in the North Sea
Authors: Liu Feifei , Schrum Corinna , Daewel Ute
Published: March 2022

Identifying the mechanisms driving the variability of the air-sea exchange of carbon dioxide (CO2) in the North Sea is necessary to evaluate the consequences of human interventions such as coastal alkalinity enhancement (OAE) on this societally important ecosystem. For this purpose, the three-dimensional coupled physical-biological model SCHISM-ECOSMO, encompassing a carbonate chemistry module, is employed to present the local physical-biogeochemical processes as well as the exchange processes across scales and compartments. Here we present model results for a 5-year simulation (2002-2004), which are shown to agree well with the observations, indicating a net CO2 uptake in the northern North Sea (NNS) over the year while a net source of CO2 to the air in summer in the southern North Sea (SNS). In the NNS, the ‘Continental Shelf Pump’ mechanism, attributing to the seasonal stratification and efficient carbon export, determines the CO2 exchange, making the ocean a net sink despite the high temperature in summer that contributes to an enhancement of the CO2 release. In contrast, the temperature-driven release of CO2 outcompetes the biological CO2 drawdown in the shallower SNS. In this region, the tidal mixing prevents seasonal stratification. As a result, the CO2 generated via remineralization gets quickly in contact with the atmosphere. In addition, the interannual variability of the CO2 flux is assessed based on the 5-year simulation, which is mainly associated with the variations of the hydrodynamic conditions and productions induced by changes of meteorological conditions.
Integrated assessment of renewable urban heating systems considering water use, committed emissions and energy justice
Authors: Kaandorp Chelsea , van de Giesen Nick , Abraham Edo
Published: March 2022

Transitioning towards renewable heating is important to minimise the use of fossil fuels and abate carbon emissions, because heating accounts for 50% of the final energy consumption and 40% of carbon dioxide emissions globally. In the city of Amsterdam, the Netherlands, the aim is to transition towards renewable heating by 2040 and achieve carbon-neutral heating by 2050 through a neighbourhood-based approach. Such an approach entails that per neighbourhood a renewable heat solution is chosen  based on criteria such as carbon emissions, reliability, affordability and feasibility. The impacts of urban heating systems however goes beyond a neighbourhood, and take place on multiple spatial and temporal scales. In this presentation we discuss how a transition towards renewable heating systems can influence the water-energy-land nexus on multiple scales in three ways.

First, heating systems use water locally, but also indirectly through the water footprint embedded in energy carriers. We therefore present an analysis of the direct and indirect water use of heating pathways towards 2050. Second, heating systems which currently have the lowest carbon emissions, may not be the heat option with the lowest carbon emissions in the future. Current decisions for heat options can therefore create non-optimal solutions for minimising carbon emissions in the future. An optimization model to find a mix of heating systems to reduce committed emissions on a neighbourhood scale within a given time period for different scenarios for the insulation of buildings and the decarbonisation of electricity generation is therefore presented. At last, new norms and forms of organising neighbourhood-based heating systems may emerge, potentially creating or exacerbating social inequalities within and beyond the spatial boundaries of a neighbourhood. We therefore present the preliminary results of an analysis on energy justice based on in-depth interviews with urban professionals, dwellers and decision makers in Amsterdam. 

By presenting these three studies we aim to address the challenge of multi-scale impacts of transitioning towards renewable urban energy systems and show how energy-water-land nexus research can contribute to decision making for urban infrastructures.
Subglacial channels, climate warming and increasing frequency of alpine glacier snout collapse
Authors: Egli Pascal , Belotti Bruno , Ouvry Boris , Irving James , Lane Stuart
Published: March 2022

Alpine glacier retreat has increased markedly since the late 1980s and is commonly linked to the effects of rising air temperature on surface melt. Less considered are processes associated with glacier snout-marginal surface collapse. A survey of 22 retreating Swiss glaciers suggests that collapse events have increased in frequency since the early 2000s, driven by ice thinning and reductions in glacier-longitudinal ice flux.

Detailed measurement of a collapse event at one glacier with Uncrewed Aerial Vehicles and ablation stakes showed 0.02 m/day vertical surface deformation above a meandering main subglacial channel, the planform of which was mapped with Ground Penetrating Radar measurements. However, with low rates of longitudinal flux (<1.3 m/year), ice creep was insufficient to close the channel in the snout marginal zone. We hypothesize that an open channel maintains contact between subglacial ice and the atmosphere, allowing greater incursion of warm air up-glacier, thus enhancing melt from below. The associated meandering of subglacial channels at glacier snouts leads to surface collapse due to erosion and internal melt as well as removal of ice via fluvial processes.
Italian viticulture and climate change
Authors: Massano Laura , Fosser Giorgia , Gaetani Marco
Published: March 2022

Italy is a world leader for viticulture and wine business. According to the 2021 National Wine Market Forum, promoted by National Wine Union (Uiv), the wine business in Italy is expected to have an annual turnover of 11 billion euros in 2022, keeping Italy at second place in the world trade market ranking. 

Our study aims to understand the impact of climate change on wine production in Italy to provide useful information to winegrowers and stakeholders involved in the wine business to make their activities more sustainable and more resilient to climate change. The climate variables that most influence grape growth are: temperature, precipitation, and evapotranspiration. Starting from these variables, we calculate a range of bioclimatic indices, selected following the International Organisation of Vine and Wine Guidelines (OIV), to be correlated with grape yield data. 

Using observations from the E-OBS gridded dataset, we investigate how the bioclimatic indices changed in the last 39 years (1980-2019), and the impact of these changes on grape productivity aggregated at the regional (NUTS2) scale. The Italian Statistic Institute (ISTAT) provides yearly grape yield data for each region, which allows us to account for specific regional grape characteristics and wine production policies. 

Our results show low and not statistically significant correlations between individual bioclimatic indices and yields in most of the NUTS2 aggregations. Climate is not the only factor that influences wine productivity. In fact, vineyard management, policies, and markets can play a major role and those data are not included in the ISTAT dataset. The study highlights the need for higher quality data, including their metadata, and the active involvement of local businesses in this type of impact study.
Deep learning for improved bias correction of satellite-derived SIS maps 
Authors: Carpentieri Alberto , Wild Martin , Folini Doris , Meyer Angela
Published: March 2022

Accurate maps of surface incoming solar (SIS) radiation are a crucial prerequisite for producing precise solar radiation and photovoltaic power (PV) nowcasts useful to utility companies, grid operators and energy traders. 

We present a new bias correction approach for satellite-retrieved SIS measurements using deep neural networks with time encoding features, achieving significantly reduced biases on high time resolution data. Moreover, we demonstrate the necessity and the benefits of automated bias correction prior to performing surface radiation and PV nowcasts.

We make use of SIS retrieved from the SEVIRI spectrometer onboard the geostationary Meteosat MSG satellite with the HelioMont (Stöckli, 2013) and HelioSat (Müller et al., 2015) algorithms by the CM SAF team. HelioMont comes at a spatial resolution of 0.02x0.02 degrees, while HelioSat provides a resolution of 0.05x0.05 degrees. For the bias correction, we employ high-quality long-term pyranometer measurements from 113 ground stations of one of the densest meteorological networks around the world, the SwissMetNet.  The SIS radiations are retrieved at 30-minutes, 15-minutes and 10-minutes resolutions (HelioSat, HelioMont, and SwissMetNet, respectively) for the entire year 2018. We use 46 weeks as training set and 6 weeks as test set, wherein the latter consists of the 3 sunniest and 3 cloudiest weeks of 2018.

Our approach involves a multilayer perceptron (MLP) trained to correct the satellite SIS bias by exploiting the predictor variables (time encoding, location features and satellite SIS) and fitting them to predict the ground station SIS. By doing so, we demonstrate that our novel bias correction method can reduce the SIS mean absolute bias (MAB) of both HelioMont and HelioSat by more than 10%. Comparing our results with a standard linear regression (LR) model, we find that the MLP outperforms the LR approach on 112 and 111 SwissMetNet stations for HelioMont and HelioSat, respectively. 

Moreover, we found that the bias magnitude is significantly correlated with the altitude of the considered location and with the time of year. The biases are largest in mountainous regions that tend to have a higher albedo due snow and ice. In fact, the Pearson correlation between the altitude and the average MAB is 0.76 and 0.80 for HelioMont and HelioSat, respectively.

 

References

R. Stöckli (2013). The HelioMont Surface Solar Radiation Processing. Scientific Report 93, MeteoSwiss, 122 pp.

Müller, R., U. Pfeifroth, C. Träger-Chatterjee, J. Trentmann, and R. Cremer (2015), Digging the METEOSAT Treasure-3 Decades of Solar Surface Radiation, Remote Sensing, 7(6), 8067-8101, doi:10.3390/rs70608067.
Secular changes in length of day induced by the redistribution potential
Authors: Escapa Alberto , Baenas Tomás , Ferrándiz José Manuel
Published: March 2022

The secular change in the length of day due to mass redistribution effects is revisited using the Hamiltonian formalism of the rotation of a two-layer deformable Earth. The dissipative effects at the core-mantle boundary are described through a coupling torque formulated by means of generalized forces. Taking advantage of the canonical procedure, a closed analytical formula for the secular deceleration of the rotation rate is obtained, which can be evaluated using frequency-dependent Love numbers corresponding to solid and oceanic tides.

Under the widespread assumption of totally coupled core and mantle layers in the long-term response, a secular angular deceleration of 1328.6 as/cy2 is calculated, equivalent to an increase of 2.418 ms/cy in the length of day. Such an estimate is in very good agreement with recent observational values and theoretical predictions based on comparable modeling features. The complete research work can be consulted in the paper by Baenas, T., Escapa, A., and Ferrándiz, J. M. (2021), entitled “Secular changes in length of day: Effect of the mass redistribution” (A&A 648, A89).

This work has been partially supported by the Spanish projects PID2020-119383GB-I00 funded by Ministerio de Ciencia e Innovación (MCIN/AEI/10.13039/501100011033/) and  PROMETEO/2021/030 funded by Generalitat Valenciana.

 
Groundwater Quality Assessment Using CCME WQI and GIS Technique for Ujjain City, India
Authors: Mohseni Usman , Patidar Nilesh , Pathan Azazkhan , Raaj Saran , Kachhawa Nitin , Agnihotri Dr. P.G , Patel Dr. Dhruvesh , Prieto Dr. Cristina , Gandhi Dr. Pankaj , Durin Dr. Bojan
Published: March 2022

Groundwater is a significant source of freshwater for people all around the world. About 97.2 % of the water on Earth is saline, with only 2.8 % available for usage as fresh water, of which approximately 20 % is groundwater. In India, a large portion of the populace relies on groundwater for drinking. The determination of water quality in residential, commercial, and industrialised areas is of great importance, and for this, the water quality index (WQI) is an effective tool which determines the suitability for drinking water of groundwater. The WQI is described as an index that reflects the combined impact of several water quality parameters that are analysed and accounted for while calculating the water quality index. In the present study, 54 groundwater samples were collected from the 54 wards of Ujjain city, Madhya Pradesh, India, during the summer period of 2019. The Bureau of Indian Standards (BIS, 2012) was used to assess the appropriateness of groundwater for drinking and calculate WQI. The water quality index was calculated using eight water quality parameters, including pH, turbidity, electrical conductivity (EC), total dissolved solids (TDS), alkalinity, chlorides (Cl–), hardness, and fluorides (F–). The objective of the study is to determine the class of all 54 samples using the Canadian Council of Ministers of Environment Water Quality Index (CCMEWQI) into five classes: excellent, good, fair, marginal, and poor. Also, the Geographic Information System (GIS) mapping technique was used to outline the spatial distribution trend of physiochemical properties and predominant ion concentration in groundwater. The obtained results suggest that wards 34 and 39 had the lowest CCMEWQI values of 32.873 and 32.120, respectively, which is unsatisfactory when compared to other wards. As a result, the general water quality of both wards (34 and 39) is poor and completely unfit for direct drinking. The CCMEWQI was found to be marginal in Wards 2, 3, 4, 6, 8, 9, 10, 12, 15, 19, 24, 25, 26, 35, 38, 40, 41, 42, 45, 46, 48, 49, and 53. Wards 5, 8, 11, 13, 14, 21, 22, 23, 28, 29, 30, 31,32, 33, 36, 50, 51, and 54 had fair water quality. CCMEWQI > 79 indicates that the water quality is good, as in Wards 20, 44, and 47. It is concluded from CCMEWQI that 6% of samples were found in the good category. 33% of the ground water samples were found to be in the range of fair quality. Similarly, 41% of samples were marginal, while 20% of samples were found to be poor. In the study area, groundwater is the main source of drinking water, so it must be managed effectively before its quality degrades.
Finding the sweet scale to understand processes and climate control over soil carbon stocks
Authors: Jungkunst Hermann , Brunn Melanie , Goepel Jan , Ott Simone , Horvath Thomas
Published: March 2022

Earth system model are designed to capture our present knowledge of soil-carbon-climate interactions. However, uncertainties remain high because mechanistic insights are available at fine scales for which we can never achieve unbiased resolution for global modeling. Consequently, the key challenge gaining global or regional overviews of soil carbon-climate feedbacks is to identify the scale that best reflects the underlying soil processes without getting lost in details. According to latest findings, the dominant control of soil carbon persistence varies with climate, which suggests that overarching proxies at a critical mesoscale combine climatic and soil factors and could enable regionally tailored approaches. Here, the Holdridge Life Zone (HLZ) classification proved to be more than a descriptive tool to guide our understanding of soil carbon-climate interaction allowing for linking top-down (from global to local) and bottom-up (from local to global) approaches. In the talk we will present the results for the indiviaul 38 HLZ and present possibilities to add soil internal controls. Regionally tailored solutions can lead to better management of soil carbon. Improving ‘translations’ from the scales relevant for process understanding to the scales of decision-making is key to sustainable soil management and to improve predictions of the fate of our largest terrestrial carbon reservoir during climate change.
High-resolution modelling of marine biogenic aerosol precursors in the Arctic realm
Authors: Zeising Moritz , Oziel Laurent , Gürses Özgür , Hauck Judith , Heinold Bernd , Losa Svetlana , Thoms Silke , Bracher Astrid
Published: March 2022

The presence of liquid or ice as cloud phase determines the climate radiative effect of Arctic clouds, and thus, their contribution to surface warming. Biogenic aerosols from phytoplankton production localized in leads or open water were shown to act as cloud condensation nuclei (liquid phase) or ice nuclei (ice phase) in remote regions. As extensive measurements of biogenic aerosol precursors are still scarce, we conduct a modelling study and use acidic polysaccharides (PCHO) and transparent exopolymer particles (TEP) as tracers. In this study, we integrate processes of algal PCHO excretion during phytoplankton growth or under nutrient limitation and processes of TEP formation, aggregation and also remineralization into the ecosystem model REcoM2. The biogeochemical processes are described by two functional phytoplankton and two zooplankton classes, along with sinking detritus and several (in)organic carbon and nutrient classes. REcoM2 is coupled to the finite-volume sea ice ocean circulation model FESOM2 with a high resolution of up to 4.5 km in the Arctic. We will present the first results of simulated TEP distribution and seasonality patterns at pan-Arctic scale over the last decades. We will elucidate drivers of the seasonal cycle and will identify regional hotspots of TEP production and its decay. We will also address possible impacts of global warming and Arctic amplification of the last decades in our evaluation, as we expect a strong effect of global warming on microbial metabolic rates, phytoplankton growth, and composition of phytoplankton functional types. The results will be evaluated by comparison to a set of in-situ measurements (PASCAL, FRAM, MOSAiC). It is further planned that an atmospheric aerosol-climate model will build on the modeled biogenic aerosol precursors as input to quantify the net aerosol radiative effects. This work is part of the DFG TR 172 Arctic Amplification.
Solar Orbiter Data-Model Comparison in Venus' Induced Magnetotail
Authors: Stergiopoulou Katerina , Jarvinen Riku , Andrews David J. , Edberg Niklas J.T. , Dimmock Andrew P. , Kallio Esa , Khotyaintsev Yuri
Published: March 2022

We investigate the Venusian magnetotail and its boundaries utilising magnetic field and density measurements that cover a wide range of radial distances, from the two geometrically similar Solar Orbiter Venus flybys on 27 December 2020 and 9 August 2021. We look at the magnetic field components along the spacecraft trajectory in an attempt to identify boundary crossings, as well as the extent and intensity of the bowshock deep in the magnetotail. We compare these observations with results of a simulation of the induced magnetosphere and magnetotail of Venus, where the initial upstream conditions are provided by Solar Orbiter measurements, to examine in what degree the simulation representation agrees with the observations. The model encloses a massive volume of 80RV x 60RV x 60RV  in which we look at magnetic field and proton density variations. Additionally, we vary the rotation of the clock angle in order to find for which rotation angle we get the best match with the observations during the different steps of the spacecraft's trajectory. 
Neural ODEs in Hydrology: Fusing Conceptual Models with Deep Learning for Improved Predictions and Process Understanding
Authors: Höge Marvin , Scheidegger Andreas , Baity-Jesi Marco , Albert Carlo , Fenicia Fabrizio
Published: March 2022

Deep learning methods have repeatedly proven to outperform conceptual hydrologic models in rainfall-runoff modelling. Although attempts of investigating the internals of such deep learning models are being made, traceability of model states and processes and their interrelations to model input and output is not fully given, yet. Direct interpretability of mechanistic processes has always been considered as asset of conceptual models that helps to gain system understanding aside of predictability. We introduce hydrologic Neural ODE models that perform as well as state-of-the-art deep learning methods in rainfall-runoff prediction while maintaining the ease of interpretability of conceptual hydrologic models. In Neural ODEs, model internal processes that are typically implemented in differential equations by hard-coding are substituted by neural networks. Therefore, Neural ODE models offer a way to fuse deep learning with mechanistic modelling yielding time-continuous solutions. We demonstrate the basin-specific predictive capability for several hundred catchments of the continental US, and exemplarily give insight to what the neural networks within the ODE models have learned about the model internal processes. Further, we discuss the role of Neural ODE models on the middle ground between pure deep learning and pure conceptual hydrologic models.