bluuebunny/crossref_metadata_2025 huggingface dataset:
Measurements of Evaporation in Urban area: A Comparison of two soil sealing types
Authors: Aljoumani Basem , Timm Anne , Sanchez Josep , Kluge Björn , Wessolek Gerd , Kleinschmit Birgit
Published: March 2021

Paved surfaces are a necessary infrastructure of cities, traditionally they are designed to carry vehicular, pedestrian traffic and transport products, and they provide public spaces for social communication. These paved surfaces also function as channels for waste matter, sewage, gas and electrical and as transport processes of water, matter, and energy between the soil and atmosphere in urban areas. In other hand, their characteristics lead to an altered hydrological balance compared to rural counterparts.

This study aimed to gain new insights into urban hydrological balance, in particular, the evaporation from paved surfaces. Hourly data of evaporation obtained from two high-resolution weighable lysimeters, these lysimeters are covered in two pavement sealing types commonly used for sidewalks in Berlin: cobblestones and concrete slabs. Soil volumetric water content and soil temperature of sandy soil was measured in the lysimeters with capacitance soil moisture sensors at 5cm depth. Moreover, time series consisted of hourly measurements climatology observations was obtained by climate station located near to the lysimeters. The measurements started in June 2016 and have been carried out for one year.

The data could be paired to estimate the variation of evaporation and how it was affected by cobblestones and concrete slabs and environmental factors.  In this case, a generalized additive model (GAM) for each sealing type was built, where the model response was the difference between the paired samples of evaporation from cobblestones and concrete slabs and the explanatory variables were the observations from the climate station and lysimeter data according to each sealing type. The statistical model tries to explain how the explanatory variables are related to a higher or lesser difference in evaporation between the two surfaces. As the result, the modelling approach showed that the evaporation from cobblestones tends to be higher than concrete slabs when the air temperate and soil temperature at 5 cm depth increases. The evaporation from cobblestone was also higher when the relative humidity was low, while the evaporation from concrete slabs was higher than cobblestones when the relative humidity was between 50 - 75%. When the relative humidity was higher than 75% the model showed that there was no difference in evaporating between the two sealing types.  The model showed also that the evaporation from concrete slabs tends to be higher than cobblestones when the solar radiation increases. Moreover, when the cumulative precipitation data in 9-hour intervals was higher than 10mm the cobblestone evaporates more than concrete slabs.
Impact of ozone on the carbon, heat and water fluxes in a land-surface model
Authors: Clancy Noel , Collins William , Vidale Pier Luigi , Folberth Gerd
Published: March 2021

Carbon uptake by land ecosystems is a hugely important carbon sink for the Earth's climate. Plants uptake carbon dioxide from the atmosphere via pores on the surface of their leaves called stomata. However, ozone can also be taken up by plants in this way leading to damage to the plant, a decrease in its growth rate and an impact on the carbon cycle. Ozone damage to plants also modifies other processes within the ecosystem such as transpiration and respiration rates, thereby effecting the hydrological cycle and energy cycle. The Joint UK Land and Environment Simulator (JULES) land-surface model includes ozone sensitivity parameters for all its vegetation cover (plant functional types). Our recent results from JULES experiments at FLUXNET sites show that ozone reduces photosynthesis and suppresses transpiration, thereby impacting the carbon, heat and water fluxes in JULES. Furthermore, we identify differences in a quantitative impact on leaf phenology.
Glacier biogeochemistry: from Haut Glacier d’Arolla to the Antarctic and Greenland Ice Sheets
Authors: Tranter Martyn
Published: March 2021

Glacier biogeochemistry grew out of hydrochemical studies of water movement through small valley glaciers in the 1970’s into modern studies of ice sheet runoff and ice berg fertilisation of the oceans. This talk will briefly review how this happened, and then look at the current research agenda with a view to identifying research needs and future research directions. Research on subglacial lakes, nutrient export to the oceans, biological ice sheet darkening and the production of bioavialable, yet ancient, dissolved organic carbon on glaciers will be covered. Finally, when you think you know it all, a new process fundamental process turns up. Recent work on the release and production of bioavailable chemicals by glacier erosion will be highlighted, including the significance of the this work in the search for life beyound Earth.  
Fingerprints of a New Normal Urban Air Quality in S5P TROPOMI Tropospheric NO2 Observations
Authors: Kondragunta Shobha
Published: March 2021

Most countries around the world took actions to control COVID-19 spread that included social distancing, limiting air and ground travel, closing schools, suspending sports leagues, closing factories etc., leading to  economic shutdown. The reduced traffic and human movement compared to Business as Usual (BAU) scenario was tracked by Apple and Android cellphone use; the data showed substantial reductions in mobility in most metropolitan areas.  We analyzed reductions in on-road mobile NOx emissions from light and heavy duty vehicles in four major metropolitan and one rural areas in the United States that showed a reduction in NOx mobile emissions from 9% to 19% between February and March at the onset of lockdown in the middle of March; between March and April, the mobile NOx emissions dropped further by 8% to 31% when lockdown measures were the most stringiest.  These precipitous drops in NOx emissions correlated well with tropospheric NO2 column amount observed by Sentinel 5 Precursor TROPospheric Ozone Monitoring Instrument (S5P TROPOMI).  Further, the changes in TROPOMI tropospheric NO2 across the continental U.S. between 2020 and 2019 correlated well with changes in on-road NOx emissions (r=0.78) but correlated weakly with changes in emissions from the power plants (r=0.44). These findings confirm that power plants are no longer the major source of NO2 in the United States. We also examined correlation between increase in unemployment rate between 2020 and 2019 to decrease in tropospheric NO2 amount.  The negative correlation indicates that with increased unemployment rate combined with telework policies across the nation for non-essential workers, the NO2 values decreased at the rate of 0.8 µmoles/m2 decrease per unit percentage increase in unemployment rate.  There is a substantial amount of scatter in the data with some cities such as Atlanta, Dallas, and Houston showing no noticeable trend in tropospheric NO2 changes during the time period when unemployment rate increased from 6% to 12%.   We examined the trends in on-road and power plant emissions for five different locations (four urban areas and one rural area) and show that the changes in NOx emissions during the lockdown are detectable in TROPOMI tropNO2 data, the economic indicators are consistent with emissions changes, and the trends reversing with the removal of lockdown measures in the major metro areas have not come back to pre-pandemic levels.  The COVID-19 pandemic experience has provided the scientific community an opportunity to identify emissions reductions scenarios that created a new normal for urban air quality and if the environmental protection agencies should look at this new normal as a guidance for instituting new policies. 
Multiple DNA-tracer transport approach for determining aquifer matrix properties in a laboratory 3D aquifer sand tank: a methodical perspective
Authors: Chakraborty Swagatam , Arachchilage Chamath , Elhaj Rayan Hamza Mohamed , Foppen Jan Willem , Bogaard Thom , Schijven Jack
Published: March 2021

Use of environmental or artificial tracers has been an effective approach to characterize groundwater flow and solute transport, tracking pollutant migration and determine travel time. However, availability of a distinctive number of tracers, variability in interaction with the aquifer matrix, and analytical detection limits are namely few of the significant concerns to be addressed and which led us to focus on employing novel DNA tracers.

Besides the quality of being unique, improbably prevalent in nature and environmentally friendly, DNA tracers can be synthesized virtually in infinite numbers of distinct sequences, rendering them a potential candidate for multi-tracer applications for subsurface and groundwater flow characterization. Studies have already demonstrated the potential of DNA tracing in groundwater studies but a blueprint for methodical application and analysis is required.

In this study, we investigate the applicability of DNA tracers in determining hydraulic parameters of a natural aquifer, such as, hydraulic conductivity, effective porosity, dispersivity, and travel time, the most significant characters of a matrix, influencing solute or pollutant transport. In addition, we aim to leverage the applicability of the tracers in terms of minimizing the uncertainty in estimating the parameters.

In order to capitalize on these advantages of DNA tracers with the aim of addressing the aforementioned objectives, this research focuses on employing multiple dsDNA (ds=double stranded) tracers in a 1.3 m long three-dimensional sand-filled aquifer tank. Under forced-gradient water flow conditions, distinctly sequenced, monodispersed dsDNA tracers are instantaneously injected through injection wells, taking into account different scenarios. The scenarios consider different configurations of injection and sampling strategies. Samples collected periodically were subjected to quantitative polymerase chain reaction (qPCR) for DNA concentration estimation. All the silica-encapsulated DNA particles were comparable in size and surface properties.

Individual breakthrough curves from each of the scenarios are carefully analysed for determining water flow and hydraulic properties. In addition, the experiments producing multiple breakthrough curves are cumulatively analysed for obtaining a minimal uncertainty for the parameter estimations.
Performance evaluation of gridded climate data in snow-melt models calibrated by spatial snow-cover observations from MODIS
Authors: Gyawali Dhiraj Raj , Bárdossy András
Published: March 2021

Considering the snow effect on land and atmospheric processes, accurate representation of seasonal snow evolution including the distribution and melt volume, is highly imperative to strengthen water resources development trajectories in mountainous regions. However, along with the high sensitivity to climate change, the limitation of reliable snow-melt estimation in these regions is further exacerbated with data scarcity. This study thus attempts to develop relatively simpler degree-day snow-models driven by freely available gridded datasets for data scarce snow-fed regions. The methodology uses readily available MODIS imageries to calibrate the snow-melt models on snow-distribution instead of snow-amount. In addition, freely available cloud masks from geostationary satellites are also used to complement the snow-melt models. The major advantage of this approach is the possibility of regional calibration using freely available reasonably accurate climate data, without the need of direct snow depth measurements. These models offer relative simplicity and plausible alternatives to data intensive physically based model as well as in-situ measurements and have a wide scale applicability allowing immediate verification with point measurements.

Bavaria region in Germany is selected for this study.  E-OBS (European Observations) gridded precipitation and temperature datasets (0.25 degrees) are considered here instead of the ground measured data to replicate “a data scarce scenario” as in most of the mountainous regions around the globe. The coarser meteorological inputs are downscaled applying the delta method using WorldClim monthly climate surfaces to 0.0833 degrees (~1km) grids. MODIS images are also resampled and upscaled to 1km resolution for uniformity. The qualitative pixel-to-pixel comparison suggest a very good agreement with MODIS data and the calibrated parameter sets depict plausible temporal stability.

The snow-melt volume will be further used in HBV hydrological model as standalone input to simulate the streamflow in one of the snow-fed catchments in Bavaria and to evaluate the performance of this approach in streamflow. The abstract will the updated as soon as the results are available.
Tools for monitoring the spatio-temporal evolution of seismic sequences: An application to the Azores triple junction
Authors: Soares Analdyne , Custodio Susana , Cesca Simone
Published: March 2021

In the last decades, the discovery of seismic signals other than those known as classical earthquakes have changed our understanding of the dynamic process of lithosphere fracturing with implications for seismic monitoring. These signals are hypothesized to be generated by slow slip on faults and/or by the motion of fluids in the crust. The earthquakes that occur in the Azores archipelago are thought to result from the interaction between a tectonic triple junction and a low-velocity (possibly hot) anomalous mantle. Although most of the seismic activity in this region is tectonic, there is also evidence of seismic activity related to hydrothermal and magmatic activity, which makes the Azores region a privileged natural observatory for studying different types of seismic signals. In this work we will then focus on the spatio-temporal evolution of the February 2018 seismic sequence which occurred in the island of São Miguel. We will carry out detection and preliminary location of seismic events using Lassie, an open-source software for earthquake detection. We will also perform waveform similarity and clustering analysis to understand the detailed spatio-temporal evolution of the crisis.

This work is funded by FCT through projects UIDB/50019/2020 – IDL and PTDC/CTAGEF/ 6674/2020 (RESTLESS).
Bivalves indicate that the North Atlantic was under stress before the onset of the Little Ice Age
Authors: Arellano Nava Beatriz , Halloran Paul R. , Boulton Chris A. , Lenton Timothy M.
Published: March 2021

The last millennium was characterised by a cooling from the Medieval Warm Period into the Little Ice Age. While strong volcanic eruptions could have triggered the onset of the Little Ice Age by reducing solar irradiance, modelling experiments suggest that it was amplified and maintained by sea ice-ocean feedbacks, including a potential abrupt weakening of the subpolar gyre. The weakening of negative feedbacks that maintain a system in a stable state, prior to an abrupt transition, can be detected as an increase in temporal autocorrelation and variability. Here we use an annually-resolved and absolutely dated shell-derived record from the North Icelandic Shelf that spans the last millennium, to detect such a loss of resilience in the marine environment leading up to the Little Ice Age transition. We find a significant increase in autocorrelation and variance in bivalve growth increments and oxygen isotopes before the transition, providing evidence consistent with loss of stability in the marine environment. This supports the idea that internal feedbacks played an important role in the Little Ice Age onset.
Estimation of the electric field and the altitude from  spectrophotometric observations in limb-viewing geometry
Authors: Garnung Matthieu , Celestin Sebastien , Farges Thomas
Published: March 2021

Sprites are bright and sudden events occuring above thunderstorms between 40 and 90 km altitude. These phenomena are usually observed using ground-based cameras and from spacecrafts. The Imager of Sprites and Upper Atmospheric Lightning (ISUAL), a payload on the FORMOSAT-2 satellite, recorded several sprite events during its mission. Contrary to JEM-GLIMS (JAXA) or ASIM (ESA), which are  space missions dedicated to the observation of TLEs from a nadir-viewing geometry, ISUAL used a limb-viewing geometry. This configuration offers the possibility to directly estimate the altitude of the event from its camera.
The challenge consists in estimating the altitude and the electric field from spectrophotometer measurements. The method of the spectrophotometric ratios consists to use ratios computed from different band systems to estimate the altitude and the electric field. It is the one of the most encouraging to achieve this goal.
In this work, we propose a method to estimate the electric field and the altitude from an observation made by the ISUAL instrument using the following ratios LBH/1PN2, 2PN2/1PN2 and LBH/1NN2+. We show that some spectroscopic ratios are more useful then others and point out some limitations of this approach that will need to be widen to nadir-viewing geometry observations.
Impact of bionanocomposite on aggregation rate of soil colloids
Authors: Kalinichenko Kira , Oliinyk Viktoria , Vorotytskyi Pavlo , Volobayev Igor
Published: March 2021

Soil degradation is a global issue, as the demand for food and feed consumption is growing rapidly every day, and agricultural land needed for their production is declining rapidly. The UN reports that 24 billion tons of fertile land are lost every year. One of the most important parameters causing and maintaining soil fertility is the presence of water-stable macroaggregates (> 0.25 mm) with a developed porous structure. In natural soil, aggregate formation occurs under the following main processes – coagulation with polyvalent cations, “glueing”/cementation under the action of mineral amorphous "glues" (silica, metal oxides/ hydroxides) and organic amphiphilic substances (microbial exopolymers and humic substances). In this research work we estimated the impact of bio-nanocomposite and its individual constituents with structure forming ability on the remediation efficacy of a degraded soil model sample.
The bio-nanocomposite was synthesised from active sludge. The composition of the bio-nanocomposite includes mineral matter – 36 %, organic matter – 64 %, humic acids, fulvic acids, ammonifying bacteria, nitrate-assimilating bacteria, actinomycetes, fungi, and metal nanoparticles in form of insoluble or sparingly soluble salts. To assess the effect of the concentration of bio-nanocomposite on the aggregation of soil colloids, the nanocomposites were added to the model soil system in concentrations of 1%, 2.5%, 5%, 10%, 20% and 50%, and compared with control unenriched soil.  The dynamics of soil colloids aggregation was assessed by the value of the optical density of aqueous suspensions at four months. The results indicate a correlation between the concentration of the introduced bio-nanocomposite and the degree of soil colloids aggregation – up to 70% after 2 months of incubation and up to 80% after 4 months. Analysis of the impact on the structure-forming processes of individual constituents of the bio-nanocomposite showed that nanoparticles of polyvalent metals made the most significant contribution (82 %), humic and fulvic acids had slightly less influence (80% and 78%, respectively). Exopolymers had the weakest effect on aggregation processes. Since exopolymers act as natural flocculants, their flocculating properties are highly dependent on the concentration, and at high concentrations they can stabilize colloidal particles.
Modelling local trend of bedrock topography by inverse modelling of Poisson’s equation
Authors: Kitterød Nils-Otto , Leblois Étienne
Published: March 2021

Bedrock topography and sediment thickness can be modelled as stochastic functions in space. These two functions are important for water storage and runoff and they are therefore essential to understand hydrological response to drought and extreme rainfall events. Digital information from remote sensing, geological mapping, and public databases comprise information which make it possible to control the estimation uncertainty. Depending on the geological history, the bedrock topography might have a complex structure in space. We present results from a case study where bedrock outcrops were exposed small patchy areas and with some scattered point information from a public well database. We modelled the estimation uncertainty by standard geostatistical methods (kriging and co-kriging), and the results showed that by including information of the outcrop locations, we were able to reduce the estimation uncertainty (Kitterød, 2017). In addition to the kriging approach, we explored numerical solutions of the Poisson equation. By this method, we modelled the bedrock surface by fitting a parabolic function to sediment thickness. This was done by inverse modelling of a global load parameter in the Poisson equation. For future research, we suggest to substituting the constant load parameter by a stochastic function in space.

References:

Kitterød, N.-O. (2017): Estimating unconsolidated sediment cover thickness by using the horizontal distance to a bedrock outcrop as secondary information, Hydrol. Earth Syst. Sci., 21, 4195-4211, https://doi.org/10.5194/hess-21-4195-2017, doi:10.5194/hess-21-4195-2017.
Evolution of the electron velocity distribution under the presence of whistler waves in the solar wind (high-cadence Solar Orbiter observations)
Authors: Bercic Laura ,   et al.
Published: March 2021

The solar coronal plasma which escapes the Sun’s gravity and expands through our solar system is called the solar wind. It consists mainly of electrons and protons, carries the Sun’s magnetic field and, at most heliocentric distances, remains weakly-collisional. Due to their small mass, the solar wind electrons have much higher thermal velocity than their positively charged counterpart, and play an important role in the solar wind energetics by carrying the heat flux away from the Sun. Their velocity distribution functions (VDFs) are complex, usually modeled by three components. While the majority of electrons belong to the low-energetic thermal Maxwellian core population, some reach higher velocities, forming either the magnetic field aligned strahl population, or an isotropic high-energy halo population. This shape of the electron VDF is a product of the interplay between
Coulomb collisions, adiabatic expansion, global and local electro-magnetic fields and turbulence.
In this work we focus on the effects of local electro-magnetic wave activity on electron VDF, taking advantage of the early measurements made by the novel heliospheric Solar Orbiter mission. The high- cadence sampling of 2-dimensional electron VDFs by the electrostatic analyser SWA-EAS, together with the EM wave data collected by the seach-coil magnetometers and electric-field antennas, part of

the RPW instrument suit, allow a direct investigation of the wave-particle energy and momentum exchange. We present the evolution of the electron VDF in the presence of quasi-parallel and oblique whistler waves, believed to be responsible for scattering the strahl and creating the halo population (Verscharen et al. 2019; Micera et al. 2020).
Seismic Structure and Tectonic Evolution of Borneo and Sulawesi
Authors: Linang Harry Telajan , Gilligan Amy , Jenkins Jennifer , Greenfield Tim , Tongkul Felix , Widiyantoro Sri , Rawlinson Nick
Published: March 2021

Borneo is located at the centre of Southeast Asia, which is one of the most active tectonic regions on Earth due to the subduction of the Indo-Australian plate in the south and the Philippines Sea plate in the east. Borneo resides on the leading edge of the Sundaland block of the Eurasian plate and exhibits lower rates of seismicity when compared to the surrounding regions due to its intraplate setting. Sulawesi, an island which lies just southeast of Borneo, is characterised by intense seismicity due to multiple subduction zones in its vicinity. The tectonic relationship between the two islands is poorly understood, including the provenance of their respective lithospheres, which may have Eurasian and/or East Gondwana origin.

Here, we present recent receiver function (RF) results from temporary and permanent broadband seismic stations in the region, which can be used to help improve our understanding of the crust and mantle lithosphere beneath Borneo and Sulawesi. We applied H-K stacking, receiver function migration and inversion to obtain reliable estimates of the crustal thickness beneath the seismic stations. Our preliminary results indicate that the crust beneath Sabah (in northern Borneo), which is a post-subduction setting, appears to be much more complex and is overall thicker (more than 35 km) than the rest of the island. In addition, we find that crustal thickness varies between different tectonic blocks defined from previous surface mapping, with the thinnest crust (23 to 25 km) occurring beneath Sarawak in the west-northwest as well as in the east of Kalimantan.

We also present preliminary results from Virtual Deep Seismic Sounding (VDSS) in northern Borneo, where from the RF results we know that there is thick and complex crust. VDSS is able to produce well constrained crustal thickness results in regions where the RF analysis has difficulty recovering the Moho, likely due to complexities such as thick sedimentary basins and obducted ophiolite sequences.
The structure of self-sustained instability, transition and turbulence in the separating boundary layer under an internal solitary wave of depression
Authors: Diamessis Peter , Sakai Takahiro , Jacobs Gustaaf
Published: March 2021

The development of the separated bottom boundary layer (BBL) in the footprint of a large-amplitude ISW of depression is examined using high-accuracy/resolution implicit Large Eddy Simulation. The talk will focus on a single relatively idealized case of a large-amplitude ISW propagating against an oncoming barotropic current with its own, initially laminar, BBL under the inevitable restriction of laboratory-scale Reynolds number. Significant discussion will be dedicated to the non-trivial computational cost of setting up and conducting the above simulation, within long domains and over long-integration times, in a high-performance-computing environment. Results will focus on documenting the full downstream evolution of the structure of the separated BBL development. Particular emphasis will be placed on the existence of a three-dimensional global instability mode, at the core of the separation bubble where typically one might assume two-dimensional dynamics. The particular instability mode is spontaneously excited and is considered responsible for the self-sustained nature of the resulting near-bed turbulent wake in the lee of the ISW. Fundamental mean BBL flow metrics will then be presented along with a short discussion for potential for particulate resuspension. The talk will close with a discussion of the relevance of the existing flow configuration to both the laboratory and ocean, in light of recent measurements in the NW Australian Shelf.
Environmental magnetism study of Lake Cadagno, Switzerland
Authors: Ali Artin , Biedermann Andrea , Berg Jasmine , Lever Mark , Vogel Hendrik
Published: March 2021

Climate affects the mineralogy and grain size of sediments deposited in lakes. These properties are reflected in the sediment magnetic properties and can be characterized using magnetic methods. As part of the Cadagno-Project, which recovered several gravity and piston cores spanning the entire lake history from the deglacial to the present from the deepest part of permanently stratified Lake Cadagno, which is due to its peculiar water column chemistry considered an early Earth ocean analogue, our study aims to define changes in climate conditions during sedimentation. Here, we present a rock magnetic dataset (low-field magnetic susceptibility and its temperature dependence, anhysteretic and isothermal remanent magnetization (ARM, IRM), acquired in various fields, AF demagnetization, and hysteresis loops) that helps characterize the concentration, mineralogy, and grain size of magnetic carriers, and their variability with depth. Susceptibility, ARM, and IRM were measured on core sediments down to a depth of 886 cm below the lake bottom, providing a high-resolution record of the sedimentary environment of Lake Cadagno over the last 11,000 years. In addition to these depth profiles, detailed rock magnetic experiments were conducted at specific depths. The cores consist of pelagic sediments, flood turbidites, and late glacial sediments. In order to determine the characteristics of the background sedimentation, only turbidite-free intervals were included in this study. The depth profiles of susceptibility, ARM and IRM have approximately similar variations with depth. They show distinct peaks at the upper parts of the pelagic sediments (156-158 cm below the lake bottom,   ̴1280-1320 cal. Yr Bp) and of the late glacial sediments (826-844 cm below the lake bottom), which can be interpreted as increased concentration of ferromagnetic minerals or as a change in the magnetic mineralogy, in addition to decreasing trend in the background. Several intervals within the pelagic sediments are dominated by low-coercivity minerals (<10 mT), while higher coercivity grains (10–100 mT) contribute significantly at (150-170, 418-448 and 719-735 cm below the lake bottom). Magnetic grain size was analyzed using a Day plot, and shows that single domain magnetite dominates at (844 cm) below the lake bottom, indicating the presence of magnetotactic bacteria, which are believed to dwell mainly in the oxic–anoxic interface where chemical gradients are high. These results provide important constraints on the environmental conditions and climate change recorded by the magnetic minerals in Lake Cadagno.
Groundwater recharge and groundwater water resources under present and future climate over the Pyrenees (France, Spain, Andorre)
Authors: Caballero Yvan , Lanini Sandra , Le Cointe Pierre , Pinson Stéphanie , Hevin Guillaume , Jódar Jorge , Lambán Javier , Zabaleta Ane , Antigüedad Iñaki , Beguería Santiago
Published: March 2021

Climate change is expected to have a significant impact on water resources in mountain areas, as it is the case of the Pyrenees range between France, Spain and Andorre. Independently of future changes on rainfall patterns, global temperature rise is likely to provoke larger and earlier snowmelt, and enhanced precipitation deficits during the dry summer season. Exploring the impacts of this future situation on groundwater is essential, as this resource is often important for drinking water, irrigation and breeding uses in mountain regions. However, studies on groundwater recharge in the context of climate change are relatively scarce, as compared to studies focusing on surface water resources.

We assessed potential groundwater recharge (part of effective precipitation that infiltrates and potentially reach the aquifers) over the Pyrenean range in the framework of the PIRAGUA project, a collaborative multi-national effort funded by the EU’s Interreg POCTEFA program. Based on a gridded (5x5 km²) meteorological dataset derived from observational data by the CLIMPY project, we estimated effective precipitation for each grid cell using a conceptual water balance scheme. The effect of the seasonal change of land cover / land use (based on the Corine Land Cover dataset) on the water budget model has been assessed, and showed the need to include this component for a more accurate simulation. Based on a spatial characterization of the land infiltration capacity, the potential groundwater recharge has been computed for homogeneous groundwater bodies. Results have been compared to the outputs of groundwater models applied on selected karstic catchments using the BALAN code, and to a general knowledge of groundwater recharge rates for different regions within the study zone. Finally, climate change impacts on future IDPR have been explored using scenarios provided by the CLIMPY project.

The Pyrenees range is a hot-spot for water resources with a tremendous impact over a much broader region in SW Europe, as Pyrenean rivers are fundamental contributors to large systems such as those of the Adour and Garonne (France) or Ebro (Spain), as well as smaller systems in the western and eastern sectors such as the Bidasoa (Spanish Basque Country), Llobregat-Ter-Muga (Catalonia), or Têt-Tech-Aude (France). Our results are relevant for the planning and management of water resources for this important transboundary region in the future, as changes in groundwater recharge will also affect water resources availability.

Acknowledgments: the project PIRAGUA, is funded by the European Regional Development Fund (ERDF) through the Interreg V-A Spain France Andorra programme (POCTEFA 2014-2020).
Characteristics Analysis of Wind Components according to the Typhoon Track Influenced in the Korean Peninsula Using a Wind Profiler Radar
Authors: Joung Min-Joung , Suh Sung-Ho , Lee Dong-In
Published: March 2021

 

 Typhoon is a tropical cyclone accompanied by strong wind and heavy precipitation. It induces high human and property damages depending on typhoon track. The typhoon influenced in the Korean Peninsula mainly passes through Jeju Island and the Southern costal area from northward the East China Sea. In this study, wind components analysis using a wind profiler radar close to the shoreline is conducted. The wind profiler radar observes the three-dimensional wind components for a fixed-point regardless of precipitation and provides high-resolution (10 min., 100 m) data for continuous analysis. The wind characteristics according to the typhoon track was investigated using the Boseong wind profiler radar (34.76 °N, 127.21 °E) located on the south coast in Korea.

 Some cases were selected as typhoons that occurred in 2010 (Dianmu, Kompasu, Malou), 2011 (Meari, Muifa) and 2012 (Khanun). For the horizontal wind analysis, there were distributed the preprocessed zonal (U) and meridional (V) wind components with time. As a result, the shape of the scatter plot and their distribution characteristics were differently shown according to the typhoon track. Dianmu and Malou had circle-shape and distributed similarly over time, however Muifa, Meari, Kompasu and Khanun displayed the line-shape, relatively. Their differences were confirmed through the quadratic regression equations by each typhoon track. In addition, the amount of change in U and V was analyzed in time series.

 These wind components analysis using ground-based observation data are expected to be applied for typhoon track analysis, prediction and natural disaster prevention.
Characterization of an optical signature of the DOM of the coastal permafrost in the Mackenzie delta, by PARAFAC analysis
Authors: Flamand Aude , Chaillou Gwénaëlle , Kipp Lauren , Whalen Dustin
Published: March 2021

Global warming increases the thawing rate of the permafrost in high northern latitudes. The Arctic soil organic carbon accounts for over 50% of global soil carbon which is roughly twice the amount present in the atmosphere. An increasing amount of the newly mobilized old organic carbon, and its associated compounds, originating from permafrost thaw, is expected to be delivered to the Arctic Ocean by rivers and groundwater discharges all along the Arctic coastline. Absorbance and fluorescence spectroscopy can be used to identify a specific optical signature of permafrost-derived solutes with the objective of studying their transport and transformation to coastal waters. Emission-excitation spectra (EEMs) from three sampling sites along the coastal area of the delta were assessed and parallel factor analysis (PARAFAC) was used to identify three different components characterizing the origin and the nature of the organic carbon present in various types of samples (massive ice, groundwater, seawater and water samples on top/bottom of slumps). This study suggests that the carbon originating from the thawing of the permafrost could indeed be traced along the coastal area of the Delta.
Robust multi-scale strategies for increasing the resilience of the Mekong Delta 
Authors: Schmitt Rafael , Giuliani Matteo , Bizzi Simone , Kondolf Mathias , Daily Gretchen , Castelletti Andrea
Published: March 2021

Rising sea levels, accelerated land subsidence, and changes in water and sediment supply from upstream basins put the major livelihoods and agriculture in global river deltas at risk. Identifying effective and robust strategies to make deltas more resilient will require to systematically address uncertainty while consider the coupling between global, basin and delta scale processes.

Here, we demonstrate a bottom-up exploratory approach to forecast land loss in the Mekong Delta by 2100 and to identify most effective management levers to fight that land loss through management on different scales. To our knowledge, this is the first time that such a robust approach is applied to study coupled delta and basin systems, thus considering the full range of drivers behind land loss and delta degradation.

For this analysis, we couple a network-scale river sediment model and a conceptual model of delta morpho-dynamics. Our land loss estimates cover a large range (20 – 90 %), driven mostly by uncertainty about accelerated subsidence from groundwater pumping. However, sediment supply from the basin plays an important role to maintain delta land, especially for low and moderate scenarios of accelerated subsidence. However, sediment supply from the basin is a function of counteracting and uncertain processes. Population growth and agriculture expansion are expected to increase erosion and sediment yield from the basin, but most of this increased sediment load will be trapped in existing and planned hydropower dams, ultimately reducing sediment delivery to the delta as a function of dam siting and design.

Using more than 2 million Monte Carlo runs of a river sediment model, we find that placement of hydropower dams is the dominant control on sediment supply, far outweighing increases in sediment yield due to land conversion or reduced sediment trapping in dams because of better sediment management. Thus, the future of the Mekong delta will be determined by renewable energy policies in the basin that strategically avoid excessive sediment trapping in dams as well as by effective water management in the delta.

Our results demonstrate (1) the need for connecting delta and basin scales for managing river deltas world-wide, (2) the contribution of basin-scale sediment management to maximize the resilience of delta land, and (3) the crucial control that dams and reservoirs exert on sediment continuity between rivers and deltas.  
An integrated system of observations driven by societal benefit
Authors: Larsen Jan Rene , Starkweather Sandy
Published: March 2021

Sustaining Arctic Observing Networks (SAON) and its committees have emerged as a vital regional facilitator for advancing sustained investments in Arctic observing and data management across a partnership of Arctic and non-Arctic countries, regional and global organizations, including those of Arctic Indigenous Peoples. The lack of a consistent, equitable and holistic planning mechanism has hampered efforts to strategically improve these systems. In response, SAON set forth a vision in its 2018-2028 strategic plan to develop a Roadmap for Arctic Observing and Data Systems (ROADS) to address this systemic shortcoming and improve linkages across independently funded efforts. ROADS will address this short-coming through generating a systems-level view of observing and data system impacts, requirements and implementation strategies under its Roadmap and engaging a diverse and inclusive group of actors to deliver it. A critical success factor for ROADS is the equitable inclusion of Indigenous Peoples in the design and development process, which presents specific challenges. These challenges include differing world views of knowledge systems and historical and current inequities that have limited the degree to which Indigenous communities and organizations can make their voices heard or support the human capacity required to engage in planning. ROADS is embedding strategies to address these challenges, particularly focused on funding Indigenous expertise.

 

ROADS is both a holistic concept, building from the societal benefit-based approach of the International Arctic Observing Assessment Framework, and one that can proceed step-wise so that the most imperative Arctic observing elements can be rapidly improved and accessed through interoperable data systems. The concept of Shared Arctic Variables (SAVs) occupies a central place in the ROADS planning process (Fig. 1). SAVs are linked to the essential variable strategies of broader global networks (e.g. Global Ocean Observing System, Global Atmospheric Watch), and through an emphasis on broadly shared societal benefit, extend their definitions in support of Indigenous-led benefit and regionally identified science and decision-making needs. Guided by a principle of benefit sharing, the ROADS process is designed to engage diverse partnerships of experts across sectors in support of integrated Arctic observing and data system development
Modelling of methane emissions from offshore oil platforms in the Norwegian sea
Authors: Pisso Ignacio , Foulds Amy , Allen Grant
Published: March 2021

Methane is a major greenhouse gas that has increased since the pre-industrial era and reducing its emissions is potentially an effective way of mitigating the radiative forcing in the short term. The oil & gas industry has a positive contribution to the global atmospheric methane budget with fugitive emissions from infrastructure installations such as offshore oil platforms. As part of the United Nations Climate and Clean Air Coalition (UN CCAC) objective to quantify global CH4 emissions from oil and gas facilities, a series of aircraft campaigns have been carried out in the Norwegian sea among other areas. We report on the Lagrangian modelling activity of the emissions and transport sensitivities used to support the flux assessment. Source identification has been carried out based on backward modelling and has proved useful to interpret observations form the in situ airborne platforms. In addition, forward modelling of the emission plume in high resolution has been applied to constraining the plume height for mass balance methods assessment. Dependency of the resulting uncertainty of the flux estimates on various factors such as the choice of the meteorology and the of the Lagrangian model parameters is also discussed.
Site effect analysis to support the future seismic microzonation of Dushanbe, Tajikistan
Authors: Hakimov Farkhod , Domej Gisela , Ischuk Anatoly , Reicherter Klaus , Cauchie Léna , Havenith Hans-Balder
Published: March 2021

Similar to other big cities in Central Asia (such as Tashkent, the capital of Uzbekistan, or Bishkek, the capital of Kyrgyzstan), the capital of Tajikistan, Dushanbe, is highly exposed to earthquake and associated secondary hazards due to its close vicinity to two active fault systems, the Hissar–Kokshal Fault located in the north of the city, and the Iyak–Vaksh Fault in the south. The most recent damaging earthquake near Dushanbe was located in the Tajik Depression in western Tajikistan, the Hissar Earthquake in 1989 (M = 5.5), causing small direct damage on buildings, but triggered extensive liquefaction phenomena and related landslide in loess deposits. The villages of Sharora and Okuli-Bolo were affected by mudflows destroying more than 100 houses, and 247 persons died.  

To ensure people’s safety, especially for a rapidly growing city such as Dushanbe, adequate constructions and a detailed seismic microzonation map (and related data) are the keys for sustainable urban planning. Existing estimations of seismic hazards date back to 1978; they are based on engineering geological investigations and observed macroseismic data. These were used to create the Tajik Building Code which considers seismic intensities according to the Medvedev–Sponheuer–Karnik Scale, MSK-64. However, this code does not accurately account for soil types which vary considerably in Dushanbe – not only by their nature but also due to increasing anthropogenic alteration. In this study, we performed a series of analyses on Microtremor Array Measurements, Seismic Refraction Tomography, and instrumental data recording from permanent as well as from mobile seismic stations (H/V method) in order to provide the site effect analysis for a new comprehensive microzonation of Dushanbe (and neighboring areas) accounting for the different soil types. Our results identify several critical areas where major damage is likely to occur during strong earthquakes.
From prototypes to first production units: blueSeis-1C Fiber Optical Gyroscope industrial solution for broadband ground motion rotation measurement at the best self-noise
Authors: Gautier Kevin , Auregan Pierrick , Laudat Theo , Guattari Frédéric
Published: March 2021

First results have been already shared about large mockup of giant Fiber-Optic Gyroscope from iXblue, having diameter as large as 1.2 meters, and the development road to reach an industrial product have been drawn.

Finally it appears that even if an improved performance is always wanted by scientists, a portable instrument remains the first criteria. Therefore blueSeis-1C is the smallest giant FOG achievable to our knowledge with only 400mm diameter. Moreover, and it has been made to allow performance tuning by the user without diameter increase.

With some delays, the first production units of blueSeis-1C are finally manufactured, and their tests results will be disclosed in this paper, including self-noise, scale factor variation in time and in temperature, bias variation in temperature, linearity, magnetic sensitivity, and transfer function.

These preliminary results will have to be confirmed soon by independent academic laboratory.
Better representing vegetation canopy structure in Earth System Models
Authors: Braghiere Renato
Published: March 2021

Addressing the impact of 3D vegetation structure on shortwave radiation transfer in Earth System Models (ESMs) is important for accurate weather forecasting, carbon budget estimates, and climate predictions. While leaf-level photosynthesis is well characterized and understood, estimates of global level carbon assimilation in the literature range from 110 to 175 PgC.yr-1. I will explore how neglecting canopy structure leads to significant uncertainties in shortwave radiation partitioning, as well as second order derived canopy properties, such as leaf area index (LAI). I will also cover how modeled carbon assimilation of the terrestrial biosphere is impacted when a satellite derived clumping index is incorporated into the UKESM. Finally, I will touch on how the clumping index might be integrated into hyperspectral ESMs to explore the theoretical relationship between canopy structure and photosynthesis.