bluuebunny/crossref_metadata_2025 huggingface dataset:
Global Terrestrial Network of Water Resources Observation Infrastructures
Authors: Dietrich Stephan , Aich Valentin , Dorigo Wouter , Recknagel Thomas , Koethe Harald , Egglestone Simon
Published: March 2021

Life on earth is closely linked to the availability of water and its variability. However, global change means that the demands placed on water resources are constantly increasing. According to the conclusions of the IPCC's 5th Assessment Report, it is likely that human activities have influenced the global water cycle since 1960. Satellite-based remote sensing of water-related parameters and operational data-assimilation services are becoming increasingly important to assess changes of the global water cycle as part of the essential climate variables (gcos.wmo.int). However, particularly over land or in the deep ocean where space-borne monitoring is not possible, in-situ data provide long-term records of changes in the various components of the hydrological cycle.

Global data centres, often operating under the auspices of UN agencies, collect and harmonise water data worldwide and make the global data sets available to the public again. Most of these relevant Global Data Centres are members of the Global Terrestrial Network of Hydrology (GTN-H) that operates under auspices of WMO and the Terrestrial observation Panel of Climate (TOPC) of the Global Climate Observing System GCOS. GTN-H links existing networks and systems for integrated observations of the global water cycle. The network was established in 2001 as a „network of networks“ to support a range of climate and water resource objectives, building on existing networks and data centres, and producing value-added products through enhanced communications and shared development. Since 2017 the GTN-H coordination is held by the International Centre for Water Resources and Global change (ICWRGC, operating under auspices of the UNESCO) aiming for a data and knowledge transfer between data providers, scientists and decision makers as well as between the different institutional bodies on UN-level inter alia the WMO, UNESCO, FAO, UNEP or GCOS.

We will demonstrate the state-of-the art of the global in-situ terrestrial water resources monitoring and draw a picture of a global water observation architecture.
As a major outcome we will share the most recent evaluation of global water storage and water cycle fluxes. Here, we assess the relevant land, atmosphere, and ocean water storage and the fluxes between them, including anthropogenic water use. Based on the assessment, we discuss gaps in existing observation systems and formulate guidelines for future water cycle observation strategies.
The incidence of unusual test morphologies of Eocene Larger benthic foraminifera: An example of Paleogene Adriatic Carbonate Platform
Authors: Ćosović Vlasta , Španiček Jelena , Drobne Katica , Mrinjek Ervin
Published: March 2021

The Paleogene Adriatic carbonate platform(s) existed within the Central NeoTethys (around 32 N paleolatitude) from the Danian to the late Eocene (Bartonian/Priabonian) and produced a succession of limestones up to 500 m thick, rich in larger benthic foraminifera (LBF). The Eocene sediments are widely distributed along the eastern Adriatic coast and have been studied for many years. Taking into account the climatic changes that took place within the Eocene (Early Eocene and Middle Eocene climatic optima, known as EECO, MECO), special attention was paid to the composition of shallow-marine foraminiferal assemblages. The studies reveal the following trends: (1) the alveolinid-dominated assemblages were replaced by nummulitid-dominated assemblages around the MECO; (2) the greater species and morphological diversity (spherical, ellipsoid, extremely elongated fusiform) of the alveolinid fauna was evident at the EECO; (3) the nummulitid-dominated fauna was characterized by less diversified assemblages compared to the alveolinid ones and by the co-occurrence of scleractinian corals, coralline red algae and aborescent foraminifera. The occurrence of twin embryos has been assigned to the early Eocene in the alveolinid populations, especially in Alveolina levantina and A. axiampla (in some sections, the frequency is greater than 5%), and these coalesced embryos have the same size as the single form (usually they are smaller). The LBF assemblages of Middle Eocene showed a greater frequency of doubled adult tests (Orbitolites sp., Nummulites sp.). The origin of these unusual morphologies is poorly known, usually described as the results of stressful conditions. Considering the timing of the appearance of such morphologies, temperature and associated changes in the shallow-marine environment could be the cause.

This study is carried out as part of the scientific project IP-2019-04-5775 BREEMECO, funded by Croatian Scientific Foundation.
Benchmarking source specific isotopic ratios of levoglucosan to better constrain the contribution of domestic heating to the air pollution
Authors: Khundadze Nana , Küppers Christoph , Kammer Beatrix , Garbaras Andrius , Masalaite Agne , Wissel Holger , Luecke Andreas , Kiendler-Scharr Astrid , Gensch Iulia
Published: March 2021

Due to the potential to fingerprint emissions, carbon stable isotopes are considered a powerful tool to get insight into sources of air pollutants and to study their atmospheric life cycle. Including the independent isotopic knowledge into chemical models, not only concentration but also isotope ratios can be predicted. This provides the possibility to differentiate the impact of source strength from that of chemical reactions in the atmosphere. In a recent study comparing Lagrangian-particle-dispersion-simulations with ambient observations, Betancourt et al. [1] (ACPD2020) found that the observed isotopic age of levoglucosan, a biomass burning tracer, agrees well with the isotopic age derived from back-plumes analyses. This showed that the wintertime aerosol burden from domestic heating observed in residential areas of North-Rheine-Westphalia, Germany, is of local or regional origin. Error analyses though indicated that the largest source of uncertainty was the limited information on emission isotope ratios.

In this work, the stable isotope ratios of levoglucosan in aerosol particles emitted from the combustion of 18 different biomass fuels typically used for domestic heating in Western and Eastern Europe (soft and hard woods, brown coals and corn cobs, respectively) were measured by Thermal Desorption- Two-Dimensional Gas Chromatographie- Isotope Ratio Mass Spectrometry (TD-2DGC-IRMS). Additionally to the compound specific measurements, isotopic ratios of total carbon in the fuel parent material, in the precursor cellulose, as well as in sampled aerosol particles were determined.

Levoglucosan δ13C was found to vary between -23.6 and -21.7‰ for the C3 plant samples, showing good agreement with Sang et al [2] (EST2012). The brown coal and the C4 plant samples were isotopically heavier, showing isotopic ratios in the range of -21,1 to -18.6‰ and -12.9‰, respectively. In this presentation, the observed levoglucosan δ13C will be discussed with respect to the carbon isotopic composition of the parent materials. The potential of using compound specific δ13C measurements of levoglucosan for improved source apportionment will be addressed.

References:
Using atmospheric in-situ measurements of 13CH4 to investigate methane emissions in Western Canada
Authors: Vogel Felix , Ars Sebastien , Muehlenbachs Karlis , Gonzalez Arismendi Gabriela , Worthy Doug
Published: March 2021

The climate change impact of methane is significant and the recent increase in its atmospheric concentrations raises great concerns. Across Canada, methane emissions are unevenly distributed with a large part attributed to the Western Canadian Sedimentary Basin (WCSB), which is the fourth largest reserve of fossil fuels in the world. The WCSB extends from northeastern British Columbia to southwestern Manitoba, encompassing Alberta and southern Saskatchewan. The extraction of  hydrocarbons mostly takes place in the provinces of Alberta and Saskatchewan and is a large source of methane.

According to recent international agreements, the Government of Canada has committed to reducing methane emissions by 40 to 45% by 2025 based on 2012 levels. However, a recent study using atmospheric measurements of methane concentrations in the region showed that methane emissions from the oil and gas sector might be nearly twice that reported in Canada’s National Inventory (Chan et al., 2020). More investigations are required to better understand the discrepancy between these two estimates.

In this study, we use atmospheric observations of δ13C measured successively at three locations across the WCSB between 2016 and 2020 to help identify the influence of different types of methane sources across the provinces of Alberta and Saskatchewan. We compare our atmospheric measurements with compilations and isotope contour maps of fugitive methane from energy facilities across the basin. Combining these measurements with trajectories computed with the HYSPLIT model developed by NOAA, we show a gradient in the methane isotopic signature across Alberta: methane being more depleted in southwestern Saskatchewan than northwestern Alberta. We also used the HYSPLIT5-STILT dispersion model to derive footprints during our measurements and estimate methane contributions of these two provinces using an optimization based on the isotopic measurements.

 

Chan et al. 2020:
 Acoustic/shock wave heating in the gravitationally stratified partially ionized plasmas: the two-fluid effects 
Authors: Zhang Fan , Poedts Stefaan , Lani Andrea , Kuźma Błażej , Murawski Kris
Published: March 2021

 The chromospheric heating problem is a long-standing intriguing topic of solar physics, and the acoustic wave/shock wave heating in the chromospheric plasma has been investigated in the last several decades. It has been confirmed that acoustic waves, and the shock waves induced by the steepening acoustic waves in the gravitationally stratified chromospheric plasma, are able to transport energy to the chromosphere, but the energy supplied in this way is not necessarily sufficient for heating the chromosphere. Here, we further investigate the acoustic/shock wave heating process while taking into account the two-fluid effects.

 As the plasma in the chromosphere is weakly or partially ionized,  neutrals play an important role in wave propagation in this region. Therefore,  a two-fluid computational model treating neutrals and charged particles (electrons and ions) as two separate fluids is used for modelling the acoustic/shock wave propagation in idealised partially ionized plasmas, while taking into account the ion-neutral collisions, ionization and recombination. We have thus investigated  the collisional and reactive interactions between separated ions and neutrals, as well as the resulting effects in the acoustic/shock wave propagation and damping. In the numerical simulations, both the initial hydrostatic equilibrium and chemical equilibrium are taken into account to provide different density profiles for comparison.

We have found that the shock heating in the partially ionized plasmas strongly depends on the ionization fraction. In particular, the relatively smaller ionization fraction resulting from the initial chemical equilibrium significantly enhances the shock wave heating, which dominates the overall heating effect according to an approximated quantitative comparison. Moreover, the decoupling between ions and neutrals is also enhanced while considering ionization and recombination, resulting in stronger collisional heating.
Perspectives and limits on the use of commercial low-cost digital MEMS accelerometers in gravimetry
Authors: Prato Andrea , Mazzoleni Fabrizio , Facello Alessio , Origlia Claudio , Schiavi Alessandro , Germak Alessandro
Published: March 2021

The value of the acceleration due to gravity is of interest in a wide range of fields, from geophysics, geodesy, water-floor monitoring, and hazard forecasting to oil, gas and mineral exploration. For this purpose, relative or absolute gravimeters have been developed and used for decades. While absolute gravimeters are mainly used in monitoring stations or as reference, relative gravimeters are those actually used to determine the relative variations of the local gravitational field given their smaller dimension, lighter weight, and better reading resolution, despite the high costs and the difficulty in being used under severe environmental conditions. In the last years, the advent of micro-electromechanical-systems (MEMS), in particular MEMS accelerometers, has opened up the doors to new measuring possibilities at very low-costs. As a consequence, different international research groups focused their efforts to develop relative MEMS gravimeters and showed that this technology might be really useful for monitoring the gravitational field. However, their current production is limited to a few specimens and prototypes that cannot be exploited on a large scale at the present day. For this reason, this work investigates the possibilities and the limits in the use of commercial digital MEMS accelerometers as relative gravimeters. The digital MEMS accelerometers investigated in this work are two commercial low-cost digital MEMS accelerometers (STM, model LSM6DSR, and Sequoia, model GEA). The first is composed of an accelerometer sensor, a charge amplifier, and an analog-to-digital converter and is connected by a serial cable to a separated external microcontroller (ST, model 32F769IDISCOVERY), in which other electronic components are integrated. The second is composed of the sensing element and the analog-to-digital converter. Both are connected to the computer via USB cable. The two devices are included in a thermally insulated case, in which a resistive heater and a resistance thermometer (PT1000), connected in loop, are placed in order to guarantee temperature stability during use. The system, installed on a tilting table to ensure higher accuracy in the evaluation of local g, is calibrated in static conditions by comparison to the absolute gravimeter IMGC-02 at a specific measurement location at INRIM. Calibration is repeated several times over a period of a few weeks in order to evaluate repeatability, reproducibility and stability over time. Despite the promising future prospects of this technology, at present, the levels of precisions are low compared to the ones required by most of geodynamics applications.
On the relationship between stable isotopes and major impurity species as inferred from a two-dimensional firn sampling approach at EDML, East Antarctica
Authors: Münch Thomas , Hörhold Maria , Freitag Johannes , Behrens Melanie , Laepple Thomas
Published: March 2021

Ice cores constitute a major palaeoclimate archive by recording, among many others, the atmospheric variations of stable oxygen and hydrogen isotopic composition of water and of soluble ionic impurities. While impurities are used as proxies for, e.g., variations in sea ice, marine biological activity and volcanism, stable isotope records are the main source of information for the reconstruction of polar temperature changes.

However, such reconstruction efforts are complicated by the fact that temperature is by far not the only driver of isotopic composition changes. A single isotopic ice-core record will comprise variations caused by a multitude of processes, from variable atmospheric circulation and moisture pathways to the intermittency of precipitation and finally to the mixing and re-location of surface snow by wind drift (stratigraphic noise). Under the assumption that specific trace components are originally deposited with the precipitated snow and its isotopic composition, the retrieved impurity records should display a similar spatial and seasonal to interannual variability as the isotope records, caused by local stratigraphic noise as well as the time-variable and intermittent precipitation patterns, respectively.

In this contribution, we investigate the possible relationship between isotope and impurity data at the East Antarctic low-accumulation site EDML. We sampled and analysed isotopic composition and major impurity species on a four metre deep and 50 metre long trench. This enables us (1) to study the spatial (horizontal times vertical) relationship in the data, and (2) to analyse and compare the seasonal and interannual variability after removing the strong contribution of local stratigraphic noise. By this, the study improves our understanding of the depositional mechanisms that play an important role for the formation of ice-core records, and it offers to investigate the potential of using impurities to correct isotopic variability in order to improve temperature reconstructions.
Extreme winds in a WRF downscaling for the SAM-22 CORDEX domain for the 1979-2018 Historical Period
Authors: Silva Natalia Pillar da , Rocha Rosmeri Porfírio da , Crespo Natália Machado , de Camargo Ricardo , Lima Jose Antonio Moreira , Kaufmann Clarisse Lacerda Gomes , Andrioni Marcelo
Published: March 2021

This study aims to evaluate how extreme winds (above the 95th percentile) are represented in a downscaling using the regional model WRF over the CORDEX South American domain in an approximate 25 km (0.22 degrees) horizontal resolution, along with CFSR as input. The main focus of the analysis resides over the coastal Brazilian region, given a large number of offshore structures from oil and gas industries subject to impact by severe events. Model results are compared with a reanalysis product (ERA5),  estimates from satellites product (Cross-Calibrated Multi-Platform Wind Speed), and available buoy data (Brazilian National Buoy Project). Downscaling results from WRF show an underestimation of maximum and extreme wind speeds over the region when compared to all references, along with overestimation in the continental areas. This directly impacts results for extreme value estimation for a larger return period and severity evaluation of extreme wind events in future climate projections. To address this, a correction procedure based on the linear relationship between severe wind from satellite and model results is applied. After linearly corrected, the extreme and maximum wind speed values increase and errors in the representation of severe events are reduced in the downscaling results.
Can a local weather station be used in place of on-site measurements for heat stress assessment in a sports setting?
Authors: Cahill Olivia , Grundstein Andrew , Walker Christian , Cooper Earl
Published: March 2021

Across the globe, exposure to environmental heat stress may impose increased health and safety hazards to active populations such as athletes and workers. Monitoring heat stress is a key component of a well-designed heat mitigation policy. Yet, the cost of several hand-held heat stress sensors may pose a financial barrier for use in many circumstances. Numerous areas, however, have existing networks of weather stations that could potentially be incorporated into monitoring heat stress. Currently, the Japanese Ministry of the Environment has set up a network of weather stations across the city to monitor environmental conditions in preparation of the 2021 Tokyo Olympic and Paralympic games. Our research question asks how representative are the values recorded at local weather stations (often located over a natural surface) to playing field conditions with various surfaces and microclimate conditions. In the U.S. the WeatherSTEM network has over 600 stations scattered across the country and measures a suite of variables relevant to heat stress including air temperature, humidity, wind speed, solar radiation and models the wet bulb globe temperature (WBGT) values. This study will compare measurements from a local WeatherSTEM station with on-site measurements taken over three different playing surfaces (grass, synthetic turf, and hardcourt tennis) in a humid subtropical climate in Athens, Georgia. U.S. It will also compare WBGT values computed using different models. Our results may provide insight not only for sports but also for the workplace which take place over various surface types and environments.
Machine Learning based Precipitation Types Classification from GEO Satellite Observations: Diagnostic Model
Authors: Upadhyaya Shruti , Kirstetter Pierre-Emmanuel
Published: March 2021

The high spatial, temporal, and spectral resolutions from the new generation of GEO satellites provide opportunities to map precipitation more accurately and enhance our understanding of precipitation processes. The research question addressed in this study is: Which predictors derived from satellite observations are significant in estimating the occurrence of a given precipitation process? Several indices from the Advanced Baseline Imager (ABI) sensor onboard the Geostationary Observing Environmental Satellite (GOES)-16 are derived and matched with surface precipitation types from the Ground Validation Multi-Radar/Multi-Sensor (GV-MRMS) system across the conterminous United States (CONUS). A machine learning (ML) based Random Forest (RF) classification is developed with several categories of predictors, such as ABI brightness temperatures (Tb) from five channels, spectral channel differences and textures, and environmental variables from the Rapid Refresh numerical forecast model (NWP).

The developed RF model displays overall classification accuracy of around 75%. Investigating the model shows that the absence of precipitation (no-precipitation) and convective types are better detected using GOES-16 derived predictors, while the detection of stratiform types is better with the NWP predictors. Simple Tbs detect no-precipitation and hail types correctly, whereas Tb textures contribute to the classification accuracy of warm stratiform and convective precipitation types. The accuracy of all precipitation types identification significantly improved with the addition of NWP predictors along with GOES-16 derived predictors. Overall, the analysis provided new insights on the monitoring of precipitation with GEO satellites and showed novel ways to diagnose ML models.
Dynamic evaluation of small urban green areas at local level using GEOBIA
Authors: Popa Ana-Maria , Onose Diana Andreea , Sandric Ionut Cosmin , Gradinaru Simona Raluca , Gavrilidis Athanasios Alexandru
Published: March 2021

Urban green infrastructure has various benefits known as ecosystem services such as regulating, cultural, provisioning and supporting services. Among the provided benefits there are decrease of air temperature, increasing humidity and mitigating urban heat island as regulating services; human-nature relations as cultural services; improving air quality, carbon sequestration as provisioning services and photosynthesis, nutrient and water cycling as supporting services. The high intensity of the urbanization process across the last decades coupled with weak legislative frameworks resulted both in large areas affected by urban sprawl and densification of the existing urban fabric. Both phenomenon generated loss in open spaces, especially green areas. In the context of the sustainable urbanization promoted by HABITAT Agenda, the knowledge related with the distribution, size and quality of urban green areas represents a priority. The study aim is to identify small urban green areas at local level at different time moments for a dynamic evaluation. We focused on small urban green areas since they are scarcely analysed even if their importance for the urban quality of life Is continuously increasing given the urbanization process. We used satellite imagery acquired by Planet Satellite Constellations, with a spatial resolution of 3.7 m and daily coverage, for extracting green areas. The images were processed using Geographic Object-Based Image Analysis (OBIA) techniques implemented in Esri ArcGIS Pro. The spatial analysis we performed generated information about distribution, surfaces, quality (based on NDVI) and dynamic of small urban green areas. The results are connected with the local level development of the urban areas we analysed, but also with the population consumption pattern for leisure services, housing, transport or other public utilities. The analysis can represent a complementary method for extracting green areas at urban level and can support the data collection for calculating urban sustainability indicators.
Supercell predictability on Iberian Peninsula using WRF-ARW model
Authors: Granda-Maestre Roberto , Calvo-Sancho Carlos , Martín Yago
Published: March 2021

Spain, having a complex topography, has many climate and weather particularities, acting in many aspects like a mini continent. This is shown in many aspects, such as supercells, which count for more than 1000 in the last 10 years. This indicates that severe weather happens yearly, and supercell thunderstorms are one of the biggest threats, producing damage to population and economical assets, which makes reliable supercell forecast for risk management and mitigation a priority.

This research evaluates supercell forecasts from the Weather Research and Forecasting (WRF-ARW) model over Spain. This first iteration analyzes 2018 supercells, trying to predict this events using three nested domains (15-3-1 km), feeded with GFS operational datasets. The configuration chosen for the model has been used in the past for a master's thesis, with great results, and thus this work aims to evalute the operational usage of this configuration for prediction with 12-36 hours of anticipation. Results so far show that around 80% of supercells could be perfectly forecasted, and another 15% could have medium forecasting skill. This results show that risk alarms could have been issued if this forecasts had being operative at the moment.
An assessment of the subsurface thermal diffusion regime at some sites in the Sierra de Guadarrama 
Authors: García Pereira Félix , González Rouco Jesús Fidel , Melo Aguilar Camilo , Schmid Thomas , Vegas Cañas Cristina , Steinert Norman
Published: March 2021

An analysis of the subsurface thermal structure of Sierra de Guadarrama, in central Spain, is provided. The question addressed herein is how the temperature perturbations at the land-atmosphere interface propagate into the subsoil and change with depth. To respond, we analyse subsoil temperature data coming from four monitoring stations belonging to Guadarrama Monitoring Network (GuMNet; https://www.ucm.es/gumnet/), which cover a vertical slope ranging from 900 to 2200 m.a.s.l and a depth profile from ground surface down to 20 m. Time series span from 2015 to 2020, with some missing periods. Thermal diffusivity values are estimated from them under the assumption of heat downward propagation according to the one-dimensional heat conduction model solution, by considering the annual cycle attenuation and phase shift with depth. In addition, the aforementioned estimation is also accomplished from adjusting amplitude attenuation curves between temperature spectra at different depths to the theoretical spectral attenuation solution for one-dimensional heat conduction, which is a negative exponential function of frequency.

Preliminary results show that thermal diffusivity increases with depth at every site. Major changes take place in the soil-bedrock transition, which is found between 5-8 m deep, depending on the site. Some material samples extracted show that bedrock consists mainly of gneiss at three sites, and granite at the other one. Mean values calculated through the whole profiles lie within 1-1.4 10-6 m2/s, which are in the range of diffusivity coefficients of gneiss and granite.
Impact of strong El Niño events on river discharge in South America
Authors: Deppner Markus , Goswami Bedartha
Published: March 2021

The impact of the El Niño Southern Oscillation (ENSO) on rivers are well known, but most existing studies involving streamflow data are severely limited by data coverage. Time series of gauging stations fade in and out over time, which makes hydrological large scale and long time analysis or studies of rarely occurring extreme events challenging. Here, we use a machine learning approach to infer missing streamflow data based on temporal correlations of stations with missing values to others with data. By using 346 stations, from the “Global Streamflow Indices and Metadata archive” (GSIM), that initially cover the 40 year timespan in conjunction with Gaussian processes we were able to extend our data by estimating missing data for an additional 646 stations, allowing us to include a total of 992 stations. We then investigate the impact of the 6 strongest El Niño (EN) events on rivers in South America between 1960 and 2000. Our analysis shows a strong correlation between ENSO events and extreme river dynamics in the southeast of Brazil, Carribean South America and parts of the Amazon basin. Furthermore we see a peak in the number of stations showing maximum river discharge all over Brazil during the EN of 1982/83 which has been linked to severe floods in the east of Brazil, parts of Uruguay and Paraguay. However EN events in other years with similar intensity did not evoke floods with such magnitude and therefore the additional drivers of the 1982/83  floods need further investigation. By using machine learning methods to infer data for gauging stations with missing data we were able to extend our data by almost three-fold, revealing a possible heavier and spatially larger impact of the 1982/83 EN on South America's hydrology than indicated in literature.
Co-Designing Mobile Applications for Data Collection: A Comparative Evaluation of Co-Design Processes in the Project "Nachtlicht-BüHNE"
Authors: Klan Friederike , Kyba Christopher C.M. , Schulte-Römer Nona , Kuechly Helga U. , Oberst Jürgen , Margonis Anastasios , Hauenschild Marius
Published: March 2021

Data collection via mobile software applications is playing an increasingly important role in Citizen Science projects. When developing such applications, it is important to consider both the requirements of the scientists interested in data collection and the needs of the citizen scientists who contribute data. Citizens and participating scientists therefore ideally work together when conceptualizing, designing, and testing such applications (co-design). In this way, both sides - scientists and citizens - can contribute their expectations, desires, knowledge, and engagement at an early stage, thereby improving the utility and acceptance of the resulting applications. How such a co-design process must and can be meaningfully designed depends very much on (1) the interests, skills and background knowledge of the project participants, (2) the complexity and type of the data collection methodology to be implemented, and (3) the time, financial and legal conditions under which the software is developed.

In our contribution, we address this point. We present two methodologies that enable the joint design and implementation of software applications for mobile data collection in citizen science projects. These represent quite different best practice approaches that emerged during the development of mobile applications on the topics of light pollution and meteor observation in our Citizen Science project Nachtlicht-BüHNE. We examine and compare the resulting methods with respect to their suitability for use under different conditions and thus provide future citizen science projects based on participatory developed mobile applications with decision support for the design of their co-design approach. We shed light on the two co-design methods with respect to the following criteria, among others: possible types of contributions by volunteers, requirements on expertise and knowledge of the contributors, flexibility of the method with respect to changing requirements, possibilities with respect to the design of complex data collection methods, costs incurred and time required for the implementation of the methodology.
A 2011-2018 Fukushima Perspective on North Pacific Mode Water Pathways
Authors: Macdonald Alison , Yoshida Sachiko , Rypina Irina
Published: March 2021

This investigation uses the tracer information provided by the 2011 direct ocean release of radio-isotopes, (137Cs, ~30-year half-life and 134Cs, ~2-year half-life) from the Fukushima Dai-ichi nuclear power plant (FDNPP) together with hydrographic profiles to better understand the origins and pathways of mode waters in the North Pacific Ocean. While using information provided by radionuclide observations taken from across the basin, the main focus is on the eastern basin and results from analyses of two data sets 2015 (GO-SHIP) and 2018 (GEOTRACES) along the 152°W meridian. The study looks at how mode waters formed in the spring of 2011 have spread and mixed, and how they have not. Our radiocesium isotope samples tell a story of a surprisingly confined pathway for these waters and suggest that circulation to the north into the subpolar gyre occurs more quickly than circulation to the south into the subtropical gyre. They indicate that in spite of crossing 6000 km in their journey across the Pacific, the densest 2011 mode waters stayed together spreading by only a few hundred kilometers in the north/south direction, remained subsurface (below ~200 m) for most of the trip, and only saw the atmosphere again as they followed shoaling density surfaces into the boundary of the Alaska Gyre. The more recent data are sparse and do not allow direct measurement of the FDNPP specific 134Cs, however they do provide some information on mode water evolution in the eastern North Pacific seven years after the accident. 
A New Database of Meteorological and Glaciological Observations: Tarija Glacier, Tropical Andes
Authors: Fuchs Pablo , Mendoza Javier
Published: March 2021

We present a numerical and geographical database for the Tarija Glacier in the Tropical Andes (68.2° W, 16.2° S, 4820-5380 m.a.s.l.). The database consists of meteorological data, mass balance observations, and variations in glacier front positions. Meteorological data was obtained by an automatic weather station (AWS) located on the glacier surface that includes the following variables: precipitation, temperature, incoming shortwave radiation, relative humidity, wind speed and wind direction. Mass balance for this glacier was observed on a monthly basis in an ablation stake network and annually in a snow pit at 5230 m.a.s.l. The glacier front topography was monitored annually using a DGPS survey. We set up the database using the relational database engine PostgreSQL which is capable of managing geospatial data through the PostGIS extension. The SAGA system was used for image analysis and mapping. Data quality control and further processing was carried out in the R environment which has interfaces to the PostgreSQL database system and SAGA, as well as several additional packages for statistical analyses and modelling. The database contains data spanning the 2011-2018 period and would be useful for multiple applications including environmental and ecological modeling, water resources assessment, and climate change studies.
The Relationship Between Atmospheric Boundary Layer Structure, Brown Haze, and Air Pollution in Auckland, New Zealand
Authors: Marley Hannah , Dirks Kim , Neverman Andrew , McKendry Ian , Salmond Jennifer
Published: March 2021

A brown air pollution haze that forms over some international cities during the winter has been found to be associated with negative health outcomes and high surface air pollution levels. Previous research has demonstrated a well-established link between the structure of the atmospheric boundary layer (ABL) and surface air quality; however, the degree to which the structure of the ABL influences for formation of local-scale brown haze is unknown. Using continuous ceilometer data covering seven consecutive winters, we investigate the influence of the structure of the ABL in relation to surface air pollution and brown haze formation over an urban area of complex coastal terrain in the Southern Hemisphere city of Auckland, New Zealand. Our results suggest the depth and evolution of the ABL has a strong influence on severe brown haze formation. When days with severe brown haze are compared with those when brown haze is expected but not observed (based on favorable meteorology and high surface air pollution levels), days with severe brown haze are found to coincide with significantly shallower daytime convective boundary layers (~ 48% lower), and the nights preceding brown haze formation are found to have significantly shallower nocturnal boundary layers (~ 28% lower). On severe brown haze days the growth rate during the morning transition phase from a nocturnal boundary layer to a convective daytime boundary layer is found to be significantly reduced (70 m h-1) compared to days on which brown haze is expected but not observed (170 m h-1). Compared with moderate brown haze, severe brown haze conditions are found to be associated with a significantly higher proportion of days with a distinct residual layer present in the ceilometer profiles, suggesting the entrainment of residual layer pollutants may contribute to the severity of the haze. This study illustrates the complex interaction between the ABL structure, air pollution, and the presence of brown haze, and demonstrates the utility of a ceilometer instrument in understanding and predicting the occurrence of brown haze events.
Responsible production and consumption of mineral resources: mobilising geoethics as a framework for mining companies, manufacturers and other stakeholders
Authors: Bilham Nic
Published: March 2021

Geoethics is intended to provide a conceptual and practical framework for all human agents engaging with the ethical challenges that arise from their interaction with the Earth.  In recent years, it has chiefly focused on the professional roles of geoscientists and allied professionals.  Great progress has been made towards putting geoethics in its rightful place at the heart of all geoscience, elaborating and applying its principles across a wide variety of disciplines and sectors, and promoting its importance in geoscience education, training, research and professional practice.  Geoethical thinking has been developed and applied in the mining sector, through initiatives such as the IAPG White Paper on Responsible Mining, through multidisciplinary research on responsible and sustainable mining, and through responsible exploration, production and associated activities in mining companies. 

Addressing the global challenges expressed in the UN Sustainable Development Goals will depend on a vast range of mined raw materials.  It is vital that we find, extract, manage and use these resources in a responsible way, minimising environmental and social harm, and sharing the benefits we derive from them equitably.  But achieving these objectives cannot depend on geoscientists and their colleagues in the mining sector alone.  It will also require the active engagement of manufacturers sourcing raw materials across complex mineral supply chains; investors and other value chain actors; and a wide range of other stakeholders including civil society organisations, policy-makers and citizens.

There is rapidly growing recognition among this wider set of actors of the need for a transition to more sustainable systems of production and consumption of raw materials, and of the roles they can play in delivering these alongside responsible mining companies.  This presentation will consider the suitability of geoethics, as currently framed and articulated, as a basis for engagement and action by this wider set of actors, in particular for manufacturers seeking to behave responsibly.  It will draw lessons from a recent project to help a multinational consumer-facing company to develop its responsible sourcing programme, and will suggest how the principles of geoethics can best be operationalised and communicated in such settings.
In the context of Comet Interceptor: Unexpected polarimetric properties of some dust particles in cometary comae and on small bodies surfaces
Authors: Levasseur-Regourd A.Chantal , Hadamcik Edith , Lasue Jérémie , Milli Julien , Renard Jean-Baptiste
Published: March 2021

The ESA-JAXA Comet Interceptor mission is expected to flyby a dynamically new comet (or an interstellar one) and better reveal the properties of its dust particles and nucleus surface. We therefore tentatively compare polarimetric properties of dust released by some comets, as well as present on surfaces of some small bodies.

Phase curves of the linear polarization of cometary dust particles (observed in equivalent wavelength ranges) show analogous trends. Some unique dynamically new comets or fragmenting comets (e.g. C/1995 O1 Hale-Bopp, C/1999 S4 LINEAR) may nevertheless present a higher positive branch than Halley-type or Jupiter-family comets (e.g. 1P/Halley, 67P/Churyumov-Gerasimenko). Such differences are clues to differences in the properties (sizes, morphologies, complex optical indices) of the dust particles. Dust particles, ejected by nuclei frequently plunging in the inner Solar System, might indeed partly come from quite dense a surface layer, as detected on the small lobe of comet 67P by Rosetta [1].

Although polarimetric observations of surfaces of cometary nuclei are almost impossible, observations of the rather quiescent nucleus of 1P/Encke have been obtained [2].  Similarities between polarimetric properties of 1P/Encke and atypical small bodies (e.g. Phaeton and particularly Bennu [3]), and of dust in cometary comae may be pointed out. Numerical and laboratory simulations could represent a unique tool to better understand such similarities. It may also be added that dust particles originating from comets, with emphasis on those of Jupiter-family, may survive atmospheric entry, as CP-IDPs collected in the Earth’s stratosphere, and that dust found in debris disks of stellar systems shows levels of polarization similar to those of highly-polarized comets [4].

 

[1] Kofman et al., MNRAS, 497, 2616-2622, 2020, [2] Boehnhardt et al., A&A, 489, 1337-1343, 2008. [3] Cellino et al., MNRAS, 481, L49-L53, 2018. [4] Levasseur-Regourd et al., PSS, 186, 104896, 2020,

 
Structure of current sheets formed in collisionless plasma turbulence
Authors: Jain Neeraj , Buechner Joerg , Munoz Patricio , Zelenyi Lev M.
Published: March 2021

Plasma turbulence is ubiquitous in space and astrophysical environments and believed to play important role in a variety of space and astrophysical phenomena ranging from the entry of  energetic particles in Earth's magnetic environment and non-adiabatic heating of the solar wind plasma to star formation in inter stellar medium. Space and astrophysical plasmas are usually magnetized and collisionless. An unsolved problem in turbulent collisionless plasmas, e.g., the solar wind, is the mechanism of dissipation of macroscopic energy into heat without collisional dissipation. A number of observational and simulation studies show that kinetic sale current sheets formed self-consistently in collisionless plasma turbulence are the sites of the dissipation. Mechanisms of dissipation in current sheets are, however,  not well understood. Free energy sources in and equilibrium structure of current sheets are important factors in the determination of the dissipation mechanism. Recent PIC hybrid simulations (with mass-less electrons) of collisionless plasma turbulence show that current sheets thin down to below ion inertial length with current carried mainly by electrons. This can lead  to embedded current sheet structure which was recently studied analytically.  We carry out 2-D PIC-hybrid simulations (with finite-mass electrons) using a recently developed code CHIEF to study the free energy sources and structure of current sheets formed in turbulence. In this paper, we focus on  the spatial gradient driven free energy sources and embedded structure of current sheets.  The results are compared to the results obtained from hybrid simulations with mass-less electrons. 
Nature Based Solution simulation design methods – A storm surge seagrass application
Authors: Pranavam Ayyappan Pillai Umesh , Pinardi Nadia , Federico Ivan , Causio Salvatore , Alessandri Jacopo , Unguendoli Silvia , Valentini Andrea
Published: March 2021

Nature Based solutions (NBS) have been presented in the recent past as a potential solution to natural and climate change adverse effects on human well-being and socio-economic activities.  In this study, we present a simulation design methodology for NBS that can mitigate the effect of storm surges and coastal erosion. The chosen NBS is marine seagrass and it will be applied to the coastal strip of the Emilia-Romagna coasts. Within the framework of the OPEn-air laboRAtories for Nature baseD solUtions to Manage environmental risks (OPERANDUM) project, the seagrass NBS is presented within a simulation design methodology consisting of the comparison between validated wave numerical simulations for the present climate and modified wave simulations with marine seagrass. In this context, the unstructured version of WAVEWATCH III (WW3) model has been implemented for simulating the wave characteristics across the Emilia-Romagna coastal strip with and without seagrass.

The calibration/validation of WW3 was carried out and sensitivity experiments using the various wind-input dissipation source packages and bottom friction formulations were also attempted to evaluate the model performances (validation results presented here are for the entire 2017 year). The ST6 physics along with SHOWEX bottom friction formulations were chosen ideal for the study area. To evaluate the model results a directional wave rider buoy data was utilized. The model simulated significant wave parameters namely Hs (significant wave height), Tm (mean wave period) were compared with buoy observations and high correlations (0.93) were found with Hs comparison. Further the WW3 model was modified by including the modified bottom dissipation stress due to submerged vegetation, thereby incorporating the NBS as a potential mechanism for wave amplitude reduction. The seagrass species ‘Zostera marina’ was chosen in this study and comparisons showed that seagrass is capable to reduce the wave energy in the study area. Furthermore, the dependence on seagrass plant high-density and low-density scenarios, together with seagrass parameters (height and width of the seagrass) and species show the sensitivity of the results even on reduction of wave energy as obtained with different degrees by all NBS scenarios.    

Keywords: Nature-based solutions, WW3, marine seagrass, storm surge, Zostera marina.
Dynamics of physical and chemical properties of soil after agricultural abandonment in a karst region in Southwest China
Authors: Wang Ke , Wang Zhigang , Wang Jiale , Li Jianming , Sun Bei , Yang Hefei , Zhang Pingcang
Published: March 2021

Rocky desertification induced by severe deforestation has caused the water loss and soil erosion in karst regions in southeast China, limiting local social and economic developments. To prevent further rocky desertification, the farmland which had obtained by deforestation were abandoned for recovery. As soil quality improved by agriculture abandonment should be examined, it is necessary to investigate the dynamics of physical and chemical properties of soil in different ages after abandonment. In this study, 38 investigation sites were selected for soil sampling on the slopes in Longtan trough valley in Youyang County, Chongqing Municipality, China. The dominant plant species of the investigation sites were also noted during soil sampling. The sites were divided into seven age classes according to their abandonment time. Dynamics of water content, bulk density, pH, and concentration of available potassium, available phosphorus, available nitrogen, total nitrogen and organic matters were examined. It suggests that soil quality might be deteriorated right after abandonment and then improved from around 20 years after abandonment. Deterioration of soil quality may be induced by lack of plant coverage and exposure of rock outcrops which may accelerate water loss and swelling and shrinkage cycles of soil. After the formation of plant communities and litter layer above the ground, soil quality was then apparently improved. These findings can provide a potential guideline for recovery management in karst regions in southwest of China.