bluuebunny/crossref_metadata_2025 huggingface dataset:
A performance baseline for the representation of clouds and humidity for cloud-resolving ICON-LEM simulations
Authors: Kiszler Theresa , Chellini Giovanni , Ebell Kerstin , Kneifel Stefan , Schemann Vera
Published: March 2022

In the context of the Transregional Collaborative Research Center on "Arctic Amplification: Climate Relevant Atmospheric and Surface Processes, and Feedback Mechanisms”, we challenge the ICOsahedral Non-hydrostatic modelling framework ICON by performing simulations in a complex Arctic environment. Our study aims at adding a significant reference for how well ICON can perform in the Arctic and give ideas on how to improve the performance related to the microphysical parameterizations.

With the ambition to resolve the clouds directly, we used ICON in the large-eddy mode (ICON-LEM), which enables the use of a 3D Smagorinsky turbulence scheme. We further applied a two-moment microphysics scheme. The setup consists of a circular domain with 600 m resolution centred around Ny-Ålesund (Svalbard) with approx. 100 km diameter. As forcing, hourly data from a 2.4 km ICON-NWP simulation covering a limited area around the archipelago of Svalbard was used. These NWP simulations were forced with the operational global ICON forecasts. Ny-Ålesund was chosen because of its intricate topography, heterogenic surfaces and availability of observational data for comparisons.

The setup was run semi-operationally for 24 h on a daily basis for several months and therefore we were able to create statistics based on an outstandingly large data set. Using the columnar output of Ny-Ålesund we compared it to a large variety of observations (e.g. liquid water path, wind and relative humidity). This evaluation showed an astonishingly high agreement between the measurements and the simulations. For instance, the orographically influenced flow, as well as seasonal and short-range changes in humidity, are captured. Certain aspects, such as the formation of liquid vs ice in clouds, need improvement. On the whole, we could show that ICON-LEM is a useful tool to study the Arctic atmosphere and its changing climate. Further, we can continue to get a better picture of possibilities to understand the microphysical processes and improve their representation in the model.

This work was supported by the DFG funded Transregio-project TR 172 “Arctic Amplification (AC)3“.
Data-driven data assimilation to better characterize both accuracy and uncertainty of climate projections: a case study with an idealized chaotic AMOC model
Authors: Le Bras Pierre , Ailliot Pierre , Le Carrer Noémie , Ruiz Juan , Sévellec Florian , Tandeo Pierre
Published: March 2022

The multi-model ensemble approach is applied in geosciences to provide better predictions or projections, by weighting the outputs from different dynamical models. Basically, the weighting procedure relies on the choice of a performance metric to measure the closeness of individual model outputs to actual observations. The highest weight is then given to the model that best matches the observations, and so forth. Model weights can be used to constrain both the mean and the uncertainty in future projections of climate models.

In this study, we seek to combine different parameterizations of an idealized three-dimensional chaotic model of the Atlantic Meridional Overturning Circulation. One of the parameterizations plays the role of the observations. Each parameterization is evaluated online in a data assimilation framework using the EnKF by comparing the forecasts with the observations.

Traditional data assimilation procedures require access to the model equations, resulting in significant computational costs to run multiple model simulations to obtain forecasts at each time step. Here, a machine learning approach is implemented to provide the forecasts (i.e., analog forecasting). For each parameterization, the classical way of producing the forecasts is, in our case, replaced by an already existing catalog of trajectory time evolutions (e.g., long-term simulations), allowing to statistically emulate the model dynamics. This data-driven methodology retains the benefits given by the classical EnKF (i.e., optimal initial conditions, uncertainties consideration), at low computational costs. For each model-parameterization, a local performance metric (namely, the contextual model evidence) is computed at each time step in order to compare observations and model forecasts. This metric, based on the innovation likelihood, is sensitive to differences in the model dynamics and takes into account both the uncertainties of the forecasts and of the observations. To validate the methodology, different case studies are performed with various sensitivity tests (e.g., changing the parameterization used for the observations).

The results of the proposed weighting scheme on projections are discussed considering different quality metrics compared to benchmark methodologies. These include the equally weighting approach (also called the “model democracy”) and the direct comparison between the climatological probability distributions of simulations and observations.
Analysis of thermal regimes at Tenerife(Canary Islands) with Independent Component Analysis applied to time series of Remotely Sensed Land Surface Temperatures
Authors: Stroppiana Daniela , Przeor Monika , D’Auria Luca , Tizzani Pietro
Published: March 2022

Land surface temperature (LST) is a manifestation of the surface thermal environment (LSTE) and an important driver of physical processes of surface land energy balance at local to global scales. Tenerife is one of the most heterogeneous islands among the Canaries from a climatological and bio-geographical point of view. We study the surface thermal conditions of the volcanic island with remote sensing techniques. In particular, we consider a time series of Landsat 8 (L8) level 2A images for the period 2013 to 2019 to estimate LST from surface reflectance (SR) and brightness Temperature (BT) images. A total of 26 L8 dates were selected based on cloud cover information from metadata (land cloud cover < 10%) to estimate pixel-level LST with an algorithm based on Radiative Transfer Equations (RTE). The algorithm relies on the Normalized Difference Vegetation Index (NDVI) for estimating emissivity pixel by pixel. We apply the Independent Component Analysis (ICA) that revealed to be a powerful tool for data mining and, in particular, to separate multivariate LST dataset into a finite number of components, which have the maximum relative statistical independence. The ICA allowed separating the land surface temperature time series of Tenerife into 11 components that can be associated with geographic and bioclimatic zones of the island. The first ten components are related to physical factors, the 11th component, on the contrary, presented a more complex pattern resulting possibly from its small amplitude and the combination of various factors into a single component. The signal components recognized with the ICA technique, especially in areas of active volcanism, could be the basis for the space-time monitoring of the endogenous component of the LST due to surface hydrothermal and/or geothermal activity. Results are encouraging, although the 16-day revisit frequency of Landsat reduces the frequency of observation that could be increased by applying techniques of data fusion of medium and coarse spatial resolution images. The use of such systems for automatic processing and analysis of thermal images may in the future be a fundamental tool for the surveillance of the background activity of active and dormant volcanoes worldwide.
Satellite-based investigation of the impact of COVID-19 restrictions on cloud properties in industrial regions
Authors: Saiprakash Athulya , Sourdeval Odran
Published: March 2022

The understanding of aerosols and their impact on climate via their interactions with clouds remains one of the largest uncertainty to our current estimates of future climate warming. A change in the amount of aerosol in the atmosphere, whether natural or artificial, can have a direct impact on cloud particle nucleation. However, anthropogenically induced aerosol-cloud interactions (aci) are thought to counteract some of the effects of global warming, quantifying their effect on total radiative forcing is vital for future climate predictions.

To tackle this problem, recent research has focused on so-called natural laboratories in order to better understand aci, meaning experiments where aerosol emissions are relatively well localized and understood, hence removing one important aspect of the aci uncertainties. For instance, volcano eruptions, ship tracks, industrial tracks, or contrails represent such laboratories. The purpose of the study is to assess if emission restriction events can act as a natural laboratory for aci studies, almost in a reverse manner as industrial tracks. Here, we will compare regional cloud properties observed during the lockdown periods to climatologies using MODIS satellite cloud droplet number concentration (Nd) retrievals. CAMS global reanalysis and CAM-chem model simulations are used to study CCN activity and aerosol emissions during the lockdown period. This study will focus on different industrial regions to examine if there are any clear signals of aci. It is found that there is no significant decrease in Nd during lockdown compared to climatology at a regional scale. Although there is a reduction in various anthropogenic activities such as industrial emissions, motor vehicle emissions, etc but the background CCN conditions played an important role in the influence of Nd.
Quantifying transport ability of hindcast and forecast ocean models 
Authors: Agaoglou Makrina , García-Sánchez Guillermo , Marcano Larrinaga Amaia , Mouttapa Gabriel , Mancho Ana M.
Published: March 2022

In the last years, there has been much interest in uncertainty quantification involving trajectories in ocean data sets. As more and more oceanic data become available the assessing quality of ocean models to address transport problems like oil spills, chemical or plastic transportation becomes of vital importance. In our work we are using two types of ocean models: the hindcast and the forecast in a specific domain in the North Atlantic, where drifter trajectory data were available. The hindcast approach requires running ocean (or atmospheric) models for a past period the duration of which is usually for several decades. On the other hand forecast approach is to predict future stages. Both ocean products are provided by CMEMS. Hindcast data includes extra observational data that was time-delayed and therefore to the original forecast run. This means that in principle, hindcast data are more accurate than archived forecast data. In this work, we focus on the comparison of the transport capacity between hindcast and forecast products in the Gulf stream and the Atlantic Ocean, based on the dynamical structures of the dynamical systems describing the underlying transport problem, in the spirit of [1]. In this work, we go a step forwards, by quantifying the transport performance of each model against observed drifters using tools developed in [2].

Acknowledgments

MA acknowledges support from the grant CEX2019-000904-S and IJC2019-040168-I funded by: MCIN/AEI/ 10.13039/501100011033, AMM and GGS acknowledge support from CSIC PIE grant Ref. 202250E001.

References

[1] C. Mendoza, A. M. Mancho, and S. Wiggins, Lagrangian descriptors and the assessment of the predictive capacity of oceanic data sets, Nonlin. Processes Geophys., 21, 677–689, 2014, doi:10.5194/npg-21-677-2014

[2] G.García-Sánchez, A.M.Mancho, and S.Wiggins, A bridge between invariant dynamical structures and uncertainty quantification, Commun Nonlinear Sci Numer Simulat 104, 106016, 2022, doi:10.1016/j.cnsns.2021.106016 
Current and future contribution of filter-feeding gelatinous zooplankton to global marine biogeochemistry
Authors: Clerc Corentin , Aumont Olivier , Bopp Laurent
Published: March 2022

Filter-feeding gelatinous zooplankton (FFGZ), namely pelagic tunicates (salps, dolioids, appendicularians and pyrosomes), are increasingly recognized as an essential component of the marine ecosystem.  Long ignored because they are difficult to sample due to their fragility, these organisms play a poorly understood but essential role in the food web. First, they are prey for many organisms of interest (e.g. fish and turtles). Second, unlike other zooplankton (e.g., crustaceans) that feed on preys that are about an order of magnitude smaller, filter feeding gives them access to a much wider range of organisms, and induces a much lower prey-to-predator ratio. Moreover, salps, appendicularians and pyrosomes produce carcasses and fecal pellets that sink at extremely fast speeds (up to 1500 m/d, 10 times higher than copepods). This implies a rapid and efficient transfer of organic matter to depth. Although these organisms represent only a small proportion of the overall biomass, the induced flux of organic matter could be substantial. Current estimates, based on a very limited amount of observations, range between 0.01 PgC/year and 1 PgC/year from 100 to 1000m and are thus very uncertain. Here, we present an estimate of the influence of FFGZ on global marine biogeochemistry using the marine biogeochemical model PISCES. In our modeling framework, two processes characterize FFGZ: a preference for small prey organisms due to filter-feeding and the rapid sinking of carcasses and fecal pellets. Our simulated contribution of FFGZ to the total living marine biomass is less than 3%, but FFGZ-induced organic matter sinking at 1000m depth reaches 20%. Finally, we explore the impact of climate change on the role played by FFGZ in the marine ecosystem using 21st century climate change simulations.  As climate change is expected to benefit small-size phytoplankton in the coming decades, FFGZ could be favored over other groups of the same size range and hence would have an increasing role in sequestering carbon in the deeper ocean.
3D Spectral Induced Polarization survey to evaluate a thawing permafrost endangered hut in the Italian Alps
Authors: Moser Clemens , Maierhofer Theresa , Drigo Elisabetta , Morra Di Cella Umberto , Hauck Christian , Flores Orozco Adrian
Published: March 2022

Due to generally rising air temperatures in the European Alps in context of climate change, large areas of mountain permafrost are thawing, and subsurface pore ice is melting. Consequently, the cohesion of rock masses decreases which can constitute a threat for infrastructure like mountain huts in alpine areas. One directly affected building is the Guide Val d'Ayas al Lambronecca, a hut on a rock ledge in the Italian Alps at 3400 m above sea level. During the last decade the ground directly underneath the hut sank of about 2 m, probably due to the melting of pore ice in the subsurface below the hut. In this study, we investigate the subsurface properties beneath the hut using a 3D geophysical survey. In particular, we deploy the spectral induced polarization (SIP) method, which has emerged as a promising tool to discriminate between ice-rich and ice-poor regions in the subsurface. Our investigation is built on the hypothesis that ice can be identified in electrical images due to its high electrical resistivity and polarization (i.e., capacitive) properties at frequencies above 10 Hz. In our survey, we conducted 2D SIP measurements in summer 2020 (between 0.5 and 225 Hz) along three profiles near the hut, while real 3D SIP measurements (in the range between 1 and 240 Hz) were conducted in summer 2021. For the 3D measurements, we deployed two parallel lines, one on the southern and one on the northern rock wall of the summit where the hut is located. To improve the data quality, we used coaxial cables for the 2D measurements in 2020, while data collected in 2021 were based on the actual separation of the transmitter and receiver (i.e., instrument and cables) to reduce the contamination of the data due to parasitic electromagnetic fields. Processing of the data was based on the statistical analysis of normal and reciprocal misfits. Inversion of the data was performed in 3D using ResIPy which uses complex calculus to simultaneously resolve for the conductive and capacitive properties. Our imaging results evidence a core of ice-filled pores corresponding to high resistivity values (>10 kΩm) directly underneath the hut, this structure is overlain by lower values (<1 kΩm) in near-surface areas representing the active layer. Images of the polarization effect confirm an anomaly due to high values at frequencies above 10 Hz in the center of the rock ledge. Our study demonstrates that 3D SIP measurements can be used to differentiate between ice-rich and ice-poor areas in high mountain permafrost sites with complex topography. Moreover, 3D SIP approaches enable a detection of electrical anomalies in all three dimensions and not only along one certain direction in the case of 2D profiles. This information can be used to assess the impact of permafrost degradation on infrastructure stability in mountain regions and to support restoration actions.
Modelling and evaluating nitrogen transport from land into the ocean
Authors: Stacke Tobias , Hagemann Stefan , Thomas Helmuth
Published: March 2022

The representation of biogeochemical cycles in land surface and ocean models is advancing focusing not only on the carbon cycle but also on nutrient interactions such as nitrogen. Some land surface models (LSM) already compute leaching of these constituents from the soil, and some ocean models (OM) consider nutrient influx from the land for a number of processes, e.g. biological activity. However, the OMs usually use observed data or prescribed climatologies as input instead of the nutrient loads computed by the LSMs. This setup cannot readily represent the effects of climate or land use change on nutrient availability and therefore limits the applications of OMs or Earth System Models with respect to climate change impacts on coastal ocean biogeochemistry.

For this reason, we extended our hydrology models, the HydroPy (land surface hydrology) and the HD Model (river routing), to not only transport water but also nitrogen. Additionally, we account for several nitrogen processes like fixation, plant assimilation and denitrification on the land surface. Using atmospheric deposition and fertilizer application provided by the CMIP6 project as model inputs, we simulate the riverine nitrogen input to the ocean in a similar magnitude compared to observations. Furthermore, we include the effects of different socio-economic pathways with respect to climate change, land use change and fertilizer application in future projections. Based on these simulations – conducted at global scale with 0.5deg resolution using forcing from the GFDL-ESM4 model provided by the ISIMIP project - we present possible impacts on riverine nitrogen flow until the end of the century.
Conductivities of Titan's dusty ionosphere
Authors: Shebanits Oleg , Wahlund Jan-Erik , Waite Hunter , Dougherty Michele
Published: March 2022

Titan’s ionosphere, host to a global dusty (ion-ion) plasma, provides a unique environment for studies of dusty ionospheres, featuring one of the largest dusty plasma datasets from 126 flybys of the moon over 13 years. Recent studies have shown the charged dust to have a large impact on the electric properties of plasmas, in particular planetary ionospheres. Here we use in-situ data to derive the electric conductivities and define the conductive dynamo region at Titan.

Our results show that using the full plasma content increases the Pedersen conductivities at ~1100-1200 km altitude by up to 35% compared to only using electrons. The Hall conductivities are not consistently affected but several cases indicate a reverse Hall effect at 900 km altitude (closest approach) and below. We also discuss day-night differences, solar activity impact and compare to similar environments.
RAEGE Project: Status, Analysis Endeavours, and Future Prospects
Authors: Moreira Mariana , Azcue Esther , Puente Víctor , García Abel , Avelar Diogo , Martínez Elena , Ferreira João , González-García Javier , López-Pérez José , Cuambe Valente
Published: March 2022

RAEGE (Atlantic Network of Geodynamic and Space Stations) is a project resulting from the cooperation between the National Geographic Institute of Spain (IGN) and the Government of Azores. It is a unique project at a geodetic and geodynamic level, in which it is committed to the combination of geodetic techniques in four stations - two in Spain (Yebes and Gran Canaria) and two in Azores (Flores and Santa Maria). Santa Maria and Yebes stations are already fully implemented. The instrumentation foreseen for all four stations and that are currently implemented are radiotelescopes that use the VLBI technique, GNSS receivers, superconductive gravimetries, seismographs, and maser clocks. Furthermore, an SLR system will be shortly installed at Yebes station.

These stations are integrated into the VGOS network and in the Global Geodetic Reference System (GGOS), as multi-technique observatories. These multi-technical observatories are key in the definition of reference systems, as they allow the integration of the individual networks of each technique into a single system. Additionally, they provide an idea of the quality and precision of the systems themselves, thanks to the validation of the results between techniques. Apart from the multi-technique, the uniqueness of the RAEGE project resides in the fact that the four stations will be located on three different tectonic plates, hence their data will be of great importance to understand this triple tectonic junction.

RAEGE not only focuses on providing the necessary infrastructure for observations but also, among its objectives, to promote multi-technical geodetic analysis and obtain studies and results supported by the data collected. The purpose of this contribution is, therefore, to present the current state of the RAEGE project, including the sites and instrumentation, as well as the current analysis activities and prospects, particularly concerning the combination of the techniques present at the stations. 
Understanding the preconditioning and driving factors of the 2017 glacial lake outburst flood in the Sulzenau valley, Tyrol, Austria
Authors: Piroton Valentine , Emmer Adam , Schlögel Romy , Mergili Martin , Havenith Hans-Balder
Published: March 2022

This study focuses on Lake Sulzenau, where a Glacial Lake Outburst Flood (GLOF), involving a partial moraine-dam breach, hit the valley in August 2017 and damaged the water supply infrastructure of a nearby mountain hut. Located in the Stubai Alps (Tyrol, Austria), the Sulzenau Lake is continuously evolving due to the rapid retreat of the Sulzenauferner Glacier. The objective of this study was to use multi-source remote sensing data (optical and radar imagery, close-range and ground-based data) to obtain a detailed overview of the whole valley, to monitor the dynamics of lake evolution since its first appearance in the early 2000s, and to characterize the conditions that led to the sudden failure of the dam and its impacts. First, we used optical images (e.g.: Sentinel-2, Google Earth) to produce two detailed geomorphological maps (pre- and post-event) of Lake Sulzenau and its surroundings to identify, describe and quantify the impacts of the 2017 event on the local geomorphology. Secondly, based on multi-temporal Digital Elevation Models (DEMs), we analyzed the changes in the topography for several periods before and after the 2017 event. This step was supported by the construction of a recent DEM from Unmanned Aerial Vehicle (UAV) data collected during a field campaign completed in August 2021. The DEM differencing revealed vertical changes (erosion and deposition) in GLOF-affected areas. The Sulzenau Valley is a perfect example of the current dynamics of glacial environments under global warming. The GLOF of 2017, associated with the rapid retreat of the glacier and the recent growth of its lake, represents an excellent case study to better understand these natural hazards.
Assessing past arthropod diversity - a case study for Eocene ecosystems
Authors: Loria Stephanie F. , Kottoff Ulrich , Harms Danilo
Published: March 2022

Zoological collections of extant taxa allow assessment of biodiversity only for the past few centuries, when it was already affected by human activity. To understand present-day diversity declines, documenting biodiversity changes in fossil taxa and the drivers behind these shifts is crucial. We present an ongoing project on arthropod palaeodiversity as a case study. In this project, arthropods – particularly arachnids – in different amber deposits are examined to assess the effect of ecosystem shifts and climate variability on biodiversity from the Eocene until today and to analyze evolutionary trends and biogeographical scenarios. We aim to compare past changes with current diversity trends in order to better predict the future of our arachnid fauna.
Memory effect of soil water regime in wet forests, Norther Europe, Latvia
Authors: Kalvans Andis
Published: March 2022

Forests in hydric (wet) growing conditions are characterised by waterlogged soil conditions for a significant portion of the year with peat layer less than 30 cm. In these locations growth of most tree species is hampered due to lack of oxygen in waterlogged soil, but peat accumulation does not take place as the organic detritus is decomposed during the dry periods. These are marginal ecosystems in between wetlands and drylands and as such are sensitive to climate change. But due to their limited practical value have often been neglected by researchers.

We study the soil water regime of hydric forests constructing Hydrus-1D soil water model. The model was validated with field observations of soil water content, potential and groundwater level at three field sites in Latvia, northern Europe. The meteorological parameters for the model forcing were obtained from the E-obs data set (version v24.0e), including wind speed, relative humidity, incoming shortwave radiation, air temperature and precipitation. Model run period was from 1980 to middle of June 2021.

The model was used to explore the sensitivity of the forest water balance to the crucial parameters such as soil grain size distribution, seasonality and value of the leaf area index (LAI) and canopy surface albedo, and root system ability to compensate lack of water or waterlogged conditions in some part of the soil profile. Preliminary results indicated that there is feedback between soil aeration and transpiration. This can result in a memory effect where increased transpiration leads to soil pore water depletion, better soil aeration and further increase in transpiration and vice versa.

This work was supported by ERDF postdoctoral research project “Groundwater and soil water regime”, under climate change (No. 1.1.1.2/VIAA/3/19/524).
Coupling modelling and satellite observations to constrain subglacial melt rates and hydrology
Authors: Wearing Martin , Goldberg Daniel , Dow Christine , Hogg Anna , Gourmelen Noel
Published: March 2022

Meltwater forms at the base of the Antarctic Ice Sheet due to geothermal heat flux (GHF) and basal frictional dissipation. Despite the relatively small volume, this meltwater has a profound effect on ice-sheet stability, controlling the dynamics of the ice sheet and the interaction of the ice sheet with the ocean. However, observations of subglacial melting and hydrology in Antarctica are limited. Here we use numerical modelling to assess subglacial melt rates and hydrology beneath the Antarctic Ice Sheet. Our case study, focused on the Amery Ice Shelf catchment, shows that total subglacial melting in the catchment is 6.5 Gt yr-1, over 50% larger than previous estimates. Uncertainty in estimates of GHF leads to a variation in total melt of ±7%. The meltwater provides an extra 8% flux of freshwater to the ocean in addition to contributions from iceberg calving and melting of the ice shelf. GHF and basal dissipation contribute equally to the total melt rate, but basal dissipation is an order of magnitude larger beneath ice streams. Remote-sensing observations, from CryoSat-2, indicating active subglacial lakes and ice-shelf basal melting constrain subglacial hydrology modelling. We observe a network of subglacial channels that link subglacial lakes and trigger isolated areas of sub-ice-shelf melting close to the grounding line. Building upon this Amery case study, we expand our analysis to quantify subglacial melt rates and hydrology beneath the entire Antarctic Ice Sheet.
First results of the RAGMAC glacier elevation change intercomparison exercise
Authors: Braun Matthias , Zemp Michael , Brun Fanny
Published: March 2022

The intercomparison exercise by the IACS Working Group on Regional Assessments of Glacier Mass Change (RAGMAC) aims to provide an overview of good practises as well as spread of different processing approaches for assessing glacier volume changes from geodetic methods. It is composed of two experiments with mandatory and optional tasks. Participants are encouraged to contribute to all tasks.

Experiment 1 targets a comparison of spaceborne elevation changes to high-quality, high-resolution airborne data (either from laser scanning or aerial photogrammetry) as well as to in-situ surface glacier mass balance data. Test sites are Aletsch Glacier and Hintereisferner in the Alps as well as Vertisen in Norway. The expected outcome of the first experiment (with validation data) is to see how the participants account for the mismatch between DEM acquisition dates and to assess quantitatively the divergence between estimates as a function of this mismatch.

Experiment 2 is setup for regions (Northern Patagonian Icefield, Karakoram, Franz Joseph Land) where not direct validation data is available. The challenge posed here is on the intercomparison and influence of different processing steps and approaches on the elevation and volume change results. Observation periods are pre-defined and participants deliver different versions of the processing results.

The presentation will provide an overview of the exercise and the experiments and outline first results of the endeavour.
Climate change impact on wind and PV power generation characteristics in Europe
Authors: Scholz Yvonne , Stegen Ronald
Published: March 2022

Climate change may alter long term averages as well as short term extremes of solar irradiation and wind speed distributions. Resulting changes in the performance of wind and solar power generation capacities can impact returns on investments and security of power supply. To assess this impact and enable robust energy system planning, we use climate scenarios from global and regional climate models on an hourly basis to calculate renewable power generation potentials with our Energy Data Analysis Tool EnDAT. We investigate the development of key parameters of wind and solar power generation: annual capacity factors, minimum and maximum generation, duration of periods with extremely low generation and ramp rates. Results show that while changes are small at European average, significant changes can occur at country level. We present model results and discuss uncertainties associated with the climate scenarios and wind and solar power technology parameters as well as capacity distribution. Future research will include demand scenarios and the impact of climate change on “Dunkelflaute”-events in Europe.
Spatial deployment of Nature-based Solutions to support carbon neutrality for 50 EU cities. 
Authors: Pan Haozhi , Page Jessica , Cong Cong , Kalantari Zahra
Published: March 2022

Clear implementing plan for Nature-based solutions (NBS) beyond conceptualization is critical for successful in mitigating urban carbon emissions. In this paper, we demonstrate an approach to deploy nature-based solutions on high-resolution (25x25-meter) land use grid and its carbon emission reduction benefits for 50 major European Union (EU) cities. The deployment process takes 3 parts: 1) downgrading carbon emission data with larger spatial scales (10x10km GID data) to high-resolution cells using land use and socioeconomic data; 2) identifying opportunities and suitability of deploying NBS on these land use cells from a database with meta-analysis on the emission reduction potentials of different types of NBS; 3) Estimating total carbon emission potentials from spatial deployment and coupling of of multiple NBS with parametric simulation. Our results indicate that vast areas of urbanized and un-urbanized lands in EU cities can apply NBS to further mitigate carbon emissions. The reduction potential is huge and can contribute to a critical wedge of carbon neutrality.     
Spatial classification of typical European heatwaves using clustering 
Authors: Felsche Elizaveta , Böhnisch Andrea , Ludwig Ralf
Published: March 2022

Prolonged heat periods have become a recurring feature of the European climate. Recent events like the 2003 heatwave in France, the 2010 Russian heatwave, and the 2019 European heatwave have caused considerable economic losses due to crop failure, imposed substantial stress on the health system, and caused thousands of heat-related deaths. Due to climate change, an increase in length and frequency of heatwaves has been observed since 1950 in most regions worldwide. However, until now, little knowledge is available on the generalized patterns of heatwaves since most studies focus on the analysis of single historical heatwave events.

This study aims to increase the general understanding of heatwaves by identifying and analyzing stable classes, i.e., recurring patterns, of heatwaves present in Europe. In this study, we use data from a regional climate model large ensemble (Canadian Regional Climate Model version 5, CRCM5-LE) consisting of 50 possible realizations of climate in the years 1981-2010 in the EUR-11 domain. We use the 95th percentile of three days' mean temperature as a threshold of heatwave occurrence. Those events are additionally filtered to at least one percent of the land area to ensure that the events have a considerable spatial extent. We repeatedly apply hierarchical agglomerative clustering to find a dozen stable heatwave patterns in Europe. Those results are in good correspondence with clustering on an observational dataset (E-OBS) and when comparing those to historical events. Therefore it is shown that the catastrophic historical events can be explained as an extreme manifestation of the same recurring pattern.

Moreover, we analyze the obtained typical patterns regarding a precipitation deficit present before or after the event. We find that, e.g., after a summer heatwave in South-East Europe, there is a high chance of having increased precipitation in autumn, while no such trend can be observed in Scandinavia. Moreover, the study serves as a blueprint for the analysis of other spatial extreme events (e.g., droughts). 
Modeling soil moisture at the Valencia Anchor Station (VAS), Eastern Spain.
Authors: Carbo Ester , Juan Pablo , Añó Carlos , Chaudhuri Somnath , Diaz-Avalos Carlos , López-Baeza Ernesto
Published: March 2022

The prediction of spatial and temporal variation of soil water content brings numerous benefits in the studies of soil. However, it requires a considerable number of covariates to be included in the study, complicating the analysis. Integrated nested Laplace approximations (INLA) with stochastic partial differential equation (SPDE) methodology is a possible approach that allows the inclusion of covariates in an easy way.

The current study has been conducted using INLA-SPDE to study soil moisture in the area of the Valencia Anchor Station (VAS), soil moisture validation site for the European Space Agency SMOS (Soil Moisture and Ocean Salinity). The data used were collected in a typical ecosystem of the semiarid Mediterranean conditions, subdivided into physio-hydrological units (SMOS units) which presents a certain degree of internal uniformity with respect to hydrological parameters and capture the spatial and temporal variation of soil moisture at the local fine scale. The use of the INLA-SPDE methodology presents the possibility to analyze the significance of different covariates having spatial and temporal effects and has allowed us to fit spatial and temporal hierarchical models that are too complicated to be fitted by maximum likelihood methods.

The models allow to analyze the influence of hydrodynamic properties on VAS soil moisture (texture, porosity/bulk density and soil organic matter and land use) filtering out the effect of spatial and temporal variation. With the goal of understanding the factors that affect the variability of soil moisture in the SMOS pixel (50 km x 50 km), five states of soil moisture are proposed (moisture values range from values near saturation to moisture values near wilting point). Regarding the different models for the different Soil Moisture states, a general pattern was detected where both porosity and organic matter are two significant elements in all the cases. The model with all covariates and spatial effect has the lowest DIC value. In addition, the correlation coefficient was close to 1 for the relationship between observed and predicted values.

The findings of this study demonstrate an advancement in that framework, demonstrating that it is faster than previous methodologies, provides significance of individual covariates, is reproducible, and is easy to compare with models. The use of this methodology permits to design more efficient sampling campaigns for future SMOS missions. In addition, it also allows to construct soil moisture maps in a more sensible and efficient way.

 
PFAS transport in the unsaturated zone
Authors: Dahan Ofer , Hinrichsen Helena , Knud Erik , Dondero Francesco , Tsakiroglou Christos
Published: March 2022

Characterization of contaminants transport in the subsurface is a key component for any measures required for either prevention of water resources pollution or remediation of contaminated sites. Yet, most water resources pollution start with down percolation of contaminated water from land surface through the unsaturated zone to the underlying groundwater, and from there to related surface water resources such as rivers and lakes. Therefore, real time monitoring of contaminant migration in the unsaturated zone is critical for both characterization of pollutants fate and to effective remediation of contaminated sites.

Per- and polyfluoroalkyl substances (PFAS), are a group of new man-made chemicals which is considered emerging contaminant that impose great concern to human health. PFAS release to the environment is attributed to many sources. Yet, decomposition of domestic and industrial waste in landfills and fire-fighting training zones, where PFAS has been heavily implemented as part of the chemical compounds which were commonly used for fire control, are considered major sources for PFAS release to the environment.

SCENARIOS, is an EU funded project, aiming at achieving new strategies and methods for detection, quantification, control and elimination of PFAS from soil, vadose zone and water. Throughout the framework of project, advanced Vadose zone Monitoring Systems (VMS) are implemented at typical PFAS contaminated sites, landfills and fire fighting training zones. Sensoil's VMS technology provides real time continuous information on water flow and contaminant migration through the unsaturated zone, from land surface to the water-table. Analysis of unique data on PFAS transport in the subsurface, with respect to the site-specific hydro-geological, chemical and climatic conditions creates the base-ground for setting up the optimal remediation strategy. The mobility of PFAS in natural unsaturated zones, as measured in full scale field conditions, will be analysed by combining measurements of their interfacial properties with experiments in porous media models and multi-scale numerical models able to describe the fate of PFAS from the pore-scale to aquifer-scale.
Assessment of the Finite VolumE Sea Ice Ocean Model (FESOM2.0), with respect to Partial bottom cells, embedded sea ice and vertical mixing library CVMix
Authors: Scholz Patrick , Sidorenko Dmitry , Danilov Sergey , Koldunov Nikolay , Wang Qiang , Sein Dmitry , Jung Thomas
Published: March 2022

In this study we will present the second part of the assessment and evaluation of the unstructured-mesh Finite-volumE Sea ice-Ocean Model version 2.0 (FESOM2.0). It focuses on the performance of partial cells, embedded sea ice and on the effect of mixing parameterisations available through the CVMix package.

It is shown that partial cells and embedded sea ice lead to significant improvements in the representation of the Gulf Stream and North Atlantic Current as well as the circulation of the Arctic Ocean. In addition to the already existing Pacanowski and Phillander (fesom_PP) and K-profile (fesom_KPP) parameterisations for vertical mixing in FESOM2.0, we document the impact of several mixing parameterisations from the Community Vertical Mixing (CVMix) project library. Among them are the CVMix versions of Pacanowski and Phillander (cvmix_PP) and K-profile (cvmix_KPP) parameterisations, the tidal mixing parameterisation (cvmix_TIDAL), a vertical mixing parameterisation based on turbulent kinetic energy (cvmix_TKE) as well as a combination of cvmix_TKE and the recent scheme for the computation of the Internal Wave Dissipation, Energy and Mixing (IDEMIX). Further, we show the benefit from using a parameterisation of southern hemisphere sea ice melt season mixing in the surface layer (MOMIX) for reducing Southern Ocean hydrographic biases in FESOM2.0.
The role of the Aleutian Low in driving Pacific Decadal Variability
Authors: Dow William , Maycock Amanda , McKenna Christine , Trascasa Castro Paloma , Joshi Manoj , Smith Doug , Blaker Adam
Published: March 2022

Variability in the Aleutian Low is a known contributor to North Pacific sea surface temperature (SST) variability, but its role in forcing the basin-wide SST anomalies that characterise Pacific Decadal Variability (PDV) is unclear owing to the difficulty of disentangling coupled atmosphere-ocean processes. Here we perform a large ensemble experiment with an intermediate complexity GCM where the winter-time Aleutian Low is nudged to an anomalously strong state during successive winters. This ensemble is compared to a free-running simulation to isolate the impacts of the anomalous Aleutian Low. The nudged experiment produces a basin-scale SST response that closely resembles PDV in the free running simulation, confirming that the Aleutian Low can force PDV-like variability. Tropical Pacific sea surface temperatures (SSTs) are significantly warmer in response to the strong Aleutian Low, demonstrating that extratropical atmospheric forcing can impart a signature in tropical SSTs. The largest tropical Pacific warming is manifest in the season following nudging (boreal spring), though anomalies persist year-round. We use the Bjerknes Stability Index to attribute the drivers of the tropical Pacific SST response and find that the thermocline feedback is key, which itself is most dominant in summer. The results lend new understanding to the potential for extratropical atmospheric forcing of tropical ocean variability.
Determining the beaming of Io decametric emissions, a remote diagnostic to probe the Io-Jupiter interaction
Authors: Lamy Laurent , Colomban Lucas , Zarka Philippe , Prangé Renée , Marques Manilo , Louis Corentin , Kurth William , Cecconi Baptiste , Girard Julien , Griessmeier Jean Mathias , Yerin Serge
Published: March 2022

We investigate the beaming of 11 Io-Jupiter decametric (Io-DAM) emissions observed by Juno/Waves, the Nançay Decameter Array and NenuFAR. Using an up-to-date magnetic field model and three different methods to position the active Io Flux Tube (IFT), we accurately locate the radiosources and determined their emission angle theta from the local magnetic field vector. These methods rely on (i) updated models of the equatorial lead angle, (ii) ultraviolet (UV) images of Jupiter's aurorae from the Hubble Space Telescope simultaneous with radio data and (iii) multi-point radio measurements. The kinetic energy E(e-) of source electrons is then inferred from theta in the framework of the Cyclotron Maser Instability. The precise position of the active IFT obtained from methods (ii) or (iii), when compared to (i), can be used to test of the effective torus plasma density. Simultaneous radio and UV observations reveal that multiple Io-DAM arcs are associated with multiple UV spots and provide the first direct evidence of an Io-DAM arc associated with a trans-hemispheric beam UV spot. Multi-point radio observations alternately probe the Io-DAM sources at various altitudes, times and hemispheres. Overall, theta decreases from ~75-80° to ~70-75° over 10-40 MHz and varies both as a function of frequency (altitude) and time (longitude of Io). Its uncertainty of a few degrees is dominated by that on the longitude of the active IFT. The inferred values of E(e-), also depending on altitude and time, vary between 3 and 16 keV, in agreement with Juno in situ measurements.
Diffuse emission of 3He and 4He and thermal energy released in volcanic systems
Authors: Alonso Mar , Pérez Nemesio M. , Hernández Pedro A. , Padrón Eleazar , Melián Gladys , Rodríguez Fátima , Padilla Germán , Barrancos José , Asensio-Ramos María , Fridriksson Thrainn , Sumino Hirochika
Published: March 2022

Active or recent volcanism indicates the presence of high-enthalpy resources at depth. This is obvious when visible surface emanations as volcanic plumes, fumaroles, solfataras or bubblings appear. However, visible manifestations of deep anomalies do not always appear at the surface, making more difficult the detection of possible geothermal reservoirs. In this work, we propose that in areas where there are no visible emanations, it is possible to make an estimation of the associated thermal energy of the reservoir. For this purpose, 15 volcanic systems located in different geotectonic environments have been studied, where diffuse 3He and 4He emission and thermal energy released have been calculated. This work has focused on the study of diffuse He emissions due to its chemically conservative properties as a noble gas, helium is an excellent indicator of magmatic activity allowing to delimit permeable areas of preferential ascent of deep origin fluids. Two different methodologies for the calculation of diffuse 3He and 4He emissions have been proposed. In addition, the thermal energy released has been calculated following the methodology proposed by Chiodini et al., 2001. A consistent observation across the entire study is that those areas with relatively high diffuse 3He and 4He emissions also show relatively high thermal energy released values, suggesting a clear and positive relationship between the parameters. This implies that, in volcanic areas where no visible geothermal emanations are observed, and therefore, the inability to sample, but anomalies in the diffuse 4He emission are present, there should be a deep thermal anomaly associated, and therefore, a possible geothermal reservoir.

 

Chiodini, F. Frondini, C. Cardellini, D. Granieri, L. Marini, G. Ventura. CO2 degassing and energy release at Solfatara volcano, Campi Flegrei, Italy. J. Geophys. Res. 106 (B8) (2001) 16213e16221, https://doi.org/10.1029/2001JB000246.