bluuebunny/crossref_metadata_2025 huggingface dataset:
Drivers of water conflicts in co-evolving human-water systems in Cauvery Basin, Southern India
Authors: Srinivasan Veena , Khandekar Neha , Shinde Ganesh
Published: March 2020

 

​India is a rapidly evolving economy with rising demands from various sectors and stakeholders including the environment.  Water conflicts emerge when mechanisms to allocate water between different sectors do not keep up with changing demands. 

 

Because biophysical drivers of water availability such as industrialization, urbanization, and deforestation are driven by humans - integration of underlying socio-economic drivers with bio-physical in is, therefore, understanding water conflicts requires a socio-hydrological approach.

 

In an attempt to understand this dynamism of human-water interactions within the landscape and improve the emergence of water conflicts, we present the case of the Cauvery basin -- a highly contentious inter-state river basin in Southern India. Over a two-decade period, we explore how catchments have co-evolved by studying signatures of 53 watersheds in Cauvery basin and correlate it to the occurrence of conflict in print media. Using spatiotemporal cluster statistical analyses tools like principal component analysis in R, we explore how changes in the landscape have triggered water conflicts.
Sediment record of precipitation and changes in circulation in Bohol Sea area since the Last Glacial Maximum
Authors: Buen Sarahmae , Siringan Fernando , Lloren Ronald
Published: March 2020

Deep marine sediments may provide insights of past climate and oceanographic events. Knowledge of the past events can aid in scenario setting of future climate and their oceanographic consequences. A deep sea sediment core from the western side of Bohol Sea, a marginal sea located south of the Philippines, was used to reconstruct precipitation and identify the impacts of sea level rise on the circulation of Bohol Sea.  Five radiocarbon dates from bulk organic matter provide age control spanning back to the Last Glacial Maximum. Sedimentological (lithics and carbonate fractions; bulk density; sedimentation rate and mass accumulation rate) and geochemical (Ti, Al, Zr, Ti/Al and Y/Ni) data were used to reconstruct the sediment input for the area. Sediment input was decreasing from 20-15ka, followed by a relatively stable trend until ~9ka. After ~9ka sediment input increased up until the most recent years. Sedimentation trend follows the average winter (DJF) insolation curve at 10oN. This signifies that the sediment input reflects the general changes in precipitation in the area. Lithics and carbonate contents reflect a shift in sediment source that could be attributed to the change in circulation in the basin as the sea level rose to overtop the Surigao Strait located at the northeastern side of the basin. Greater westward transport of suspended material from large rivers to the east would contribute to the sedimentation in the western part of Bohol Sea.
Integrated modelling: a tool for combining findings from multiple studies in a hydrologic observatory
Authors: Pavlin Lovrenc , Széles Borbála , Blaschke Alfred Paul , Blöschl Günter
Published: March 2020

Research catchments allow a unique opportunity of acquiring long and varied datasets. This process takes years and is often performed by multiple generations of researchers with different research focuses. In this way, complex processes might be identified and explained on a variety of spatial and temporal scales. But how could these puzzle pieces be put together to form the complete picture of the catchment and would they even fit? Physically-based integrated surface-subsurface models, such as HydroGeoSphere, give us the possibility to jointly model a wide array of processes informed by measurable parameters. Here we present the ongoing work on conceptual models testing by an integrated model in the Hydrological open air laboratory (HOAL). This is a small headwater agricultural catchment in Lower Austria, where a variety of hydrometeorological and hydrogeochemical parameters are monitored with high spatial and temporal resolution. The model in this study builds on the conceptual models of previous studies in the catchment and incorporates features such as tile drainage system, macropores, variable land use and regional groundwater flow. Groundwater levels and discharge data at the tributaries and the catchment outlet from 2013-2017 were used for calibration. We discuss the preliminary findings and the advantages and disadvantages of this modelling approach.
Quantification of methane emissions from waste water treatment plants
Authors: Bühler Marcel , Häni Christoph , Kupper Thomas , Ammann Christof , Brönnimann Stefan
Published: March 2020

Quantification of gaseous emissions from waste water treatment plants (WWTPs) is challenging due to the heterogeneity of the emissions in space and time. The inverse dispersion method (IDM) using concentration and turbulence measurements in combination with a backward Lagrangian stochastic (bLS) dispersion model based on Flesch et al. (2004) is a promising option. It is  increasingly used to determine gaseous emissions from confined sources (Flesch et al., 2009; VanderZaag et al., 2014), as it offers high flexibility at reasonable costs. For the application on WWTPs the bLS model assumption of spatially homogeneous turbulence, which implies absence of obstacles as buildings and trees that disturbe the flow, is often not fulfilled. However, studies showed that with the correct instrument setup and data filtering the bLS can be used for emission estimates. Methane emissions from two WWTPs of different type and size were quantified using the IDM with the bLS model. Methane concentrations were analysed with open-path tunable diode laser spectrometers (GasFinder, Boreal Laser, Inc., Edmonton, Alberta, Canada) placed up- and downwind of the source. At each site at least 20 days of measurements averaged to 30-minutes intervals are available. Here we present first results from these two WWTPs emission estimates.

 

References

Flesch, T. K., Wilson, J. D., Harper, L. A., Crenna, B. P., and Sharpe, R. R.: Deducing ground-to-air emissions from observed trace gas concentrations:
A field trial, J. Appl. Meteorol., 43, 487–502, doi:10.1175/1520-0450(2004)043<0487:DGEFOT>2.0.CO;2, 2004.

Flesch, T. K., Harper, L. A., Powell, J. M., and Wilson, J. D.: Inverse-dispersion calculation of ammonia emissions from Wisconsin dairy farms, Trans. ASABE, 52, 253–265, doi:10.13031/2013.25946, 2009.

VanderZaag, A. C., Flesch, T. K., Desjardins, R. L., Baldé, H., and Wright, T.: Measuring methane emissions from two dairy farms: Seasonal and manure-management effects, Agricultural and Forest Meteorology, 194, 259–267, doi:10.1016/j.agrformet.2014.02.003, 2014.
Unravelling the complex interactions between root development and soil moisture profiles in the soil-root-system
Authors: Maan Debora Cynthia , ten Veldhuis Marie-claire , van de Wiel Bas
Published: March 2020

We  study  the coupled  action of  water  uptake  and root  development  of  maize  in Rhizotrons under greenhouse conditions. Questions we aim to answer are: What is the effect of a vertical soil moisture gradient on the root growth? How does the root structure in turn influence soil moisture? Do constant  irrigation  quantities and depths eventually lead  to  constant  root  distributions and soil moisture profiles?

We apply highly controlled subsurface irrigation schemes in potting soil-sand mixtures and measure the real-time response of the interdepending soil moisture fields and root structures.

Following a top-down approach, in which the overall behaviour of the coupled system is carefully investigated and described, we aim to unravel the complex soil-root-interaction system. Looking at the occurrence of steady states and continuities sheds light on the type of the underlying feedback loops, which in turn provides insight into the fundamental processes that underlie the typical behaviour. We are particularly interested in trade-offs between the development of rooting depth and rooting density (including its dependency on soil moisture profiles) and the coupled effect of roots and root structures on the infiltration capacity of the soil-root-system. Preliminary results suggest the possibility of an enhancing feedback loop between these processes. 

The next step will be to develop a numerical model that incorporates the interactions that were identified experimentally. The model will allow us to study the behavior and sensitivities of the system in more detail.

 
Long-term effects of precipitation removal manipulations on soil carbon balance and exchange in a Danish heathland/grassland ecosystem
Authors: Li Qiaoyan , Larsen Klaus Steenberg , Gundersen Per
Published: March 2020

The influence of drought on terrestrial carbon cycling has received great attention because of the increasing frequency of extreme drought events in climate scenarios. In the CLIMAITE experiment, we have exposed plots to reduced precipitation since 2006. During the first years, precipitation was only reduced for 4-6 weeks during spring/early summer. In order to increase our focus on finding thresholds for functional and structural change in the ecosystem, the experiment was redesigned towards more extreme manipulations in June 2016 using a new gradient design continuously removing 40, 50, and 66% of ambient precipitation with permanent rainout shelters.

Rates of net ecosystem exchange (NEE), ecosystem respiration (RE) and soil respiration (Rs) are measured inside treatment plots using an LI-6400 connected to a custom-built 210L transparent chamber (for NEE) that can be darkened (for RE) as well as a 1L dark chamber (for Rs). In addition, environmental variables such as soil temperature, precipitation, soil water content and photosynthetically active radiation (PAR) are recorded continuously at the plot or site level. In addition, soil cores from the different treatments will be collected and analyzed for soil substrate (e.g. soil organic carbon) and incubated in the lab for analysis of Q10.  Using the observations from the field and the lab together we will develop a new multiple regression model to fit the CO2 fluxes under severe precipitation removal treatments.

 

To obtain more reliable and accurate estimates of the seasonal and annual responses of soil carbon flux exchange under precipitation change scenarios, the change in soil water content and temperature, the soil substrate availability as well as the variation of the frequency and timing of precipitation events are included in the carbon flux model. The fitting of models to the observational data will reveal if functional/structural thresholds for the carbon exchange have been exceeded in the ecosystem, thus providing novel experimental and modeling evidence for such thresholds.
Biostratigraphic correlation of Miocene drillings in the Vienna Basin (Austria) - Integrated Neogene stratigraphy of the largest onshore petroleum province in Central Europe (Vienna Basin, Austria)
Authors: Kranner Matthias , Harzhauser Mathias , Mandic Oleg , Piller Werner E. , Ćorić Stjepan , Strauss Philipp , Siedl Wolfgang
Published: March 2020

Numerous boreholes of the OMV oil company penetrate the northern Vienna Basin (VB) and several detailed analyses have been conducted on these drilling for years. Despite the effort of decades, the distribution and correlation of Neogene sediments throughout the basin remained ambiguous, due to the complex fault system of the VB. To resolve remaining issues of the Neogene deposits of the area OMV initiated detailed integrative stratigraphic analyses, combining biostratigraphical, lithological, modern 3D seismic- and geophysical data.

Paleontological analysis with main focus on micropaleontology, especially foraminifers, of 46 wells (more than 650 samples) of the northern Vienna Basin have been conducted and help to create a well resolved stratigraphic north – south cross-section of the Neogene units. Of particular interest were lower and middle Miocene (Ottnangian, Karpatian, Badenian and Sarmatian) units. Hardly known and described were the patchy lower Badenian deposits and the much more complex, than previously expected, middle Badenian units. Foraminiferal analysis revealed about 50.000 specimens belonging to 228 species and an allocation to local ecozones, biostratigraphic zonations and ecological reconstructions were established.

Additionally, 50 samples have been analyzed for calcareous nannoplankton which showed extreme reworking throughout all successions.

Some samples displayed the underlying Mesozoic limestones and cutting samples of one well brought insights into the Cenozoic underling Rhenodanubian Flysch units of the Vienna Basin This huge and stratigraphic long ranging set of data did not just reveal major sedimentation gaps during the formation of the modern pull-apart basin, but also provided the opportunity to create a framework for a modern sequence stratigraphy re-assessment of the Vienna Basin.

Furthermore, a formalization of widely used formations in literature will be established in later steps of this project.

This project was financed by the OMV-AG.
Wolf spiders as biomonitors of mining derived contamination in Arctic ecosystems
Authors: Hansson Sophia V. , van Beest Floris M. , Schmidt Niels Martin , Høye Toke T. , Søndergaard Jens
Published: March 2020

The emission and spread of global contaminants such as Pb, Cd, Hg, U and rare earth elements (REE) are of high global concern as they pose a serious health risk to humans and wildlife alike. Although the Arctic is a known hot-spot for deposition of globally transported organic and inorganic contaminants, Greenland is often viewed as pristine with little influence of local emission sources. This perception is, however, flawed as Greenland hosts numerous former, active and prospected mining activities, many of which have a profound adverse impact on the surrounding environment. Detailed monitoring before, during, and after mining activities is thus essential to evaluate the environmental health status of a mining area and to minimize the potential spread of mining derived contaminants.

Arthropods constitute the majority of the terrestrial Arctic species diversity, which facilitates sampling for environmental assessment. With documented abilities to accumulate contaminant metals (e.g. Cd, Ag, Hg), we show that spiders play a key role in bioaccumulation and biomagnification processes. Acting as both predator and prey, and by linking food webs in the aquatic to the terrestrial environment, spiders can enable a continued transfer of contaminants up the food chain. Moreover, and because arthropods are an important food source for migrating birds, there is a strong potential for a further geographical spread of contaminants. However, the extent to which contaminant bioaccumulation occurs in Arctic spiders, and their role in global contaminant cycles, remain unclear.

The aim of this project and presentation is to examine the use of wolf spiders (e.g. P. glacialis, P. furcifera and P. hyperborea) as biomonitors of metal and radiogenic contamination near Arctic mine sites. Particular focus will be given to the globally prioritized elements Pb and Hg (incl. isotopic signatures), as well as contaminants of local concern such as U (incl. decay series) and REEs. Further, we discuss the role of spiders in local- to global contaminant cycles by linking the contamination transfer through onsite food webs to location data from migrating birds (e.g. GPS-trackers). Combining contamination- and location-data will allow us to model movement of biota, and inherent mining derived contamination, to and from arctic ecosystems on an annual basis.
A comparison between vegetable intercropping systems and monocultures in greenhouse gas emissions under organic management
Authors: Sánchez-Navarro Virginia , Marcos-Pérez Mariano , Zornoza Raúl
Published: March 2020

Legume crops have been proposed as a way of reducing greenhouse gas (GHG) emissions because both, their rhizosphere behaviour and their ability to fix atmospheric N reducing the need of external N fertilizer. Moreover, the establishment of organic agriculture has been proposed as a sustainable strategy to enhance the delivery of ecosystem services, including mitigation of climate change by decreases in GHG emissions and increases in soil C sequestration. The aim of this study was to assess the effect of the association between cowpea (Vigna unguiculata L.) and melon (Cucumis melo L.) growing in different intercropping patterns on soil CO2 and N2O emissions compared to cowpea and melon monocultures under organic management as a possible strategy for climate change mitigation. Soil CO2 and N2O emissions were weekly measured in melon and cowpea rows using the dynamic chamber method during one cropping cycle in 2019. Results indicated that melon growing as monoculture was related to increases in  O cumulative emissions (0.431 g m-2) compared to the average of the rest of treatments (0.036 g m-2). Cowpea growing as monoculture was related to decreases in CO2 cumulative emissions (390 g m-2) compared with the other treatments (512 g m-2 average). However, N2O and CO2 emission patterns did not directly follow soil moisture patterns in the experimental period, with no significant correlations. Finally there were no significant differences among intercropping treatments with regard to NO2 and CO2 emissions. Further measurements are needed to monitor the evolution of GHG emissions under these cropping systems and confirm the trend observed.
Sandy land structural consolidation engineering drive modern agricultural development in China’s Mu Us Sandy Land
Authors: Wang Yongsheng , Wu Wenhao , Li Yuheng
Published: March 2020

Sandification has become a major obstacle to China’s regional farmland protection, economic development and ecological civilization construction. Sandy land consolidation technologies and sustainable utilization modes will provide farmland for modern agricultural development. We introduced structural consolidation theory to sandy land rehabilitation from the aspects of soil body building, soil layer reconstruction and soil quality improvement. Filed experiments were conducted in Mu Us Sand Land to explore the effects of dry mixtures of guest material (red clay and loess) and sand at four volume ratios (1:1, 1:2, 1:3 and 1:5) on crop yield, soil properties and maize root growth. Red clay treatments had higher sandy land structural consolidation engineering costs and crop yields than loess treatments. Red clay and loess had significant promotion of maize and soybean yields at volume ratios of 1:3. The maximum potato yield is 42501 kg ha-1 and 37332 kg ha-1 in red clay treatment at volume ratio of 1:5 and in loess treatment at volume ratio of 1:5, respectively. Red clay and loess significantly increased clay and silt ratio and regulated the soil total nitrogen concentration and soil organic matter content during the critical growth stage of maize. Lowest root biomass in surface soil and lowest surface/subsoil root biomass ratio mediated maize growth in red clay treatment at volume ratio of 1:3. Red clay can be used to consolidate sandy land and develop modern agriculture in the long-term according to the engineering costs and crop yields. Enhanced land productivity, increased land transfer rent and extra wage income provide a stainable and stable increase in households’ income for escaping from poverty. Spatial overlap between red clay with sandy land makes red clay as a new available material for sand land consolidation and utilization from China to global scale. China’s sandy land structural consolidation engineering and sustainable utilization practices will contribute prescriptions to global desertification fighting and rural poverty alleviation. Regional water resource carrying capacity evaluation should be emphasized before sandy land structural consolidation engineering popularization.
Changes in snow storages and their impact on occurrence and extremity of runoff caused by rain-on-snow events
Authors: Hotovy Ondrej , Jenicek Michal
Published: March 2020

Seasonal snowpack significantly influences the catchment runoff and thus represents an important input for the hydrological cycle. Changes in the precipitation distribution and intensity, as well as a shift from snowfall to rain is expected in the future due to climate changes. As a result, rain-on-snow events, which are considered to be one of the main causes of floods in winter and spring, may occur more frequently.

The objective of this study is 1) to evaluate the frequency, inter-annual variability and extremity of rain-on-snow events in the past based on existing measurements and 2) to simulate the effect of predicted increase in air temperature on the occurrence of rain-on-snow events in the future. We selected 59 near-natural mountain catchments in Czechia with significant snow influence on runoff and with available long-time series (>35 years) of daily hydrological and meteorological variables. A semi-distributed conceptual model, HBV-light, was used to simulate the individual components of the water cycle at a catchment scale. The model was calibrated for each of study catchments by using 100 calibration trials which resulted in respective number of optimized parameter sets. The model performance was evaluated against observed runoff and snow water equivalent. Rain-on-snow events definition by threshold values for air temperature, snow depth, rain intensity and snow water equivalent decrease allowed us to analyze inter-annual variations and trends in rain-on-snow events during the study period 1980-2014 and to explain the role of different catchment attributes.

The preliminary results show that a significant change of rain-on-snow events related to increasing air temperature is not clearly evident. Since both air temperature and elevation seem to be an important rain-on-snow drivers, there is an increasing rain-on-snow events occurrence during winter season due to a decrease in snowfall fraction. In contrast, a decrease in total number of events was observed due to the shortening of the period with existing snow cover on the ground. Modelling approach also opened further questions related to model structure and parameterization, specifically how individual model procedures and parameters represent the real natural processes. To understand potential model artefacts might be important when using HBV or similar bucket-type models for impact studies, such as modelling the impact of climate change on catchment runoff.
DASH of Water – water distribution system modelling in the age of smart water meters
Authors: Steffelbauer David , Blokker Mirjam , Knobbe Arno , Abraham Edo
Published: March 2020

Worldwide, water utilities face exceptional challenges as communities are running out of water and new resources are ill-equipped to meet rising water demands. Furthermore, in many cities, years of stringent financial constraints on water utilities, unoptimized operations and the unaffordability for utilities to maintain and replace their aging infrastructure has resulted in dramatically growing leakage levels, especially in places already under high water stress. Even in Europe, as a matter of fact, nearly one quarter of treated water is lost in the distribution systems before reaching the customers. As a result, the aging water infrastructure is challenged to become more efficient.

Nowadays, an increasing number of water utilities use hydraulic simulation software to design and operate water systems in a more efficient way. However, measurements in water distribution are scarce, which results in inaccurate computer models of real systems. Recently, smart meters have become available as a promising remedy. These smart meters measure water usage of households and transmit information to water utilities in real-time. Now is the time to make water distribution simulation software fit for the future, by exploiting this new Big-data source and start a new era in hydraulic modeling, aiming to increase the operational efficiency of our drinking water systems and save our precious water resources.

This work proposes an innovative new way of combining hydraulic models, data from smart meters and stochastic demand modelling to develop beyond state-of-the-art methods to simulate water distribution systems. It is shown how data science algorithms (e.g. dynamic time warping, clustering, demand disaggregation, household activity identification, …) can be used to extract high-level information from smart meter data (e.g. daily water use routines, work schedules, socio-economic characteristics). Such information is crucial for simulating water demand accurately. Hence, data science algorithms can be used to automatically parametrize stochastic demand models (e.g. SIMDEUM) based on smart meter data, and improve their accuracy. The improved demand models are coupled with hydraulic simulations, leading to a more realistic way of simulating real water systems. Examples on a wide range of real-world applications show how these novel modelling approaches can be used to increase the operational efficiency of drinking water systems. For instance, more accurate models enable faster detection and localization of leaks in water pipes and, thus, minimize distribution losses. This work is part of the project “DASH of Water”, which aims to develop advanced data-driven stochastic hydraulic (DASH) models of drinking water distribution systems.
Forecasting forest dynamics with the individual-based model LAVESI across the Siberian treeline: from UAV surveys to simulations
Authors: Kruse Stefan , Shevtsova Iuliia , Brieger Frederic , Wieczorek Mareike , Pestryakova Luidmila A. , Herzschuh Ulrike
Published: March 2020

Boreal forests in Siberia store huge amounts of aboveground carbon. Global warming potentially threatens this carbon storage due to more frequent droughts or other disturbances such as fires. These disturbances can change recruitment patterns, and thus may have long-lasting impacts on population dynamics. Assessing high-resolution forest stand structures and forecasting their response for the upcoming decades with detailed models is needed to understand the involved key processes and consequences of global change.

We present forest stand inventories derived from UAV imagery and a developed processing chain including Individual Tree Detection (ITD) and species determination for 56 sites on a bioclimatic gradient at the Tundra-Taiga-Ecotone in Northeastern Siberia. We will use these and further 58 traditional count and measurement data as starting points for the detailed individual-based spatially explicit forest model LAVESI to predict future forest dynamics covering multiple sites across the Siberian treeline.

In our analyses, we will focus on assessing future structural changes of the forests and their aboveground biomass dynamics. For our discussion, we will evaluate the reliability of UAV-derived forest inventories by measuring the impact strength of error sources introduced in the methodology on the forecasts.
Modeling the biogeochemical dynamics of the Northern Adriatic Sea with an explicit benthic-pelagic coupling
Authors: Scroccaro Isabella , Zavatarelli Marco , Lovato Tomas
Published: March 2020

A high resolution three-dimensional (physical-biogeochemical) numerical model of the Northern Adriatic Sea has been implemented by coupling the European general circulation model - NEMO (Nucleus for European Modeling of the Ocean, https://www.nemo-ocean.eu/), with the marine biogeochemical model BFM (Biogeochemical Flux Model, bfm-community.eu/).

The modeling system is implemented with a horizontal resolution of about 800 m and a vertical resolution of 2 m, in z coordinates. The NEMO model is off-line nested at its open boundary with the Mediterranean Sea physical model of the Copernicus Marine Environment Monitoring Service (CMEMS, http://marine.copernicus.eu/).

The BFM component of the modeling system now includes a detailed and explicit representation of the benthic biogeochemical cycling (benthic fauna, organic matter, nutrients), as well as the dynamics of the benthic-pelagic processes.

The inclusion of the benthic dynamics in the 3D biogeochemical modeling of a shallow coastal basin, such as the Northern Adriatic Sea, represents an innovative application in the field of coastal and shelf biogeochemistry, since benthic biogeochemical processes can significantly constrain the coastal environmental dynamics.

Simulations have been performed in hindcasting mode with interannually varying physical (surface heat and water fluxes, including river runoff) and biogeochemical (river nutrient load) forcing. Results are validated against available observations from in situ and satellite platforms for sea surface temperatures, chlorophyll-a and dissolved inorganic nutrients, in order to explore the sensitivity of the pelagic environment to the inclusion of an explicit benthic dynamics and to evaluate issues related to model coupling and error/prediction limits.

The study is carried out in the framework of the European Project H2020 "ODYSSEA" (Operating a network of integrated observatory systems in the Mediterranean SEA, http://odysseaplatform.eu/), with the final goal to build an on-line forecasting modeling system of the Northern Adriatic Sea.
Emerging mechanisms of ecosystem functioning in a warmer and drier world
Authors: Grünzweig José M. , De Boeck Hans J. , Rey Ana , Tzuk Omer , Meron Ehud , Flores Omar , Santos Maria J. , Bahn Michael
Published: March 2020

Ecosystems are expected to face a significantly warmer and drier climate in the coming decades. Experiments have tried to unravel drought responses of ecosystems in mesic and humid biomes, but the structure and functioning of these systems may change when climatic regime shifts occur. Here, we summarize major mechanisms typical of drylands and indicate how these may come into play when current mesic ecosystems face tipping points in a warmer and drier world.

These dryland mechanisms of ecosystem functioning encompass (i) processes of vegetation development, such as self-organization of vegetation patchiness and formation of biological soil crust, (ii) biologically driven biogeochemical and physiological processes, such as drying-wetting cycles and hydraulic redistribution, and (iii) abiotically driven biogeochemical processes, such as photochemical degradation of organic matter and soil hydrophobicity. We present insights from published studies and original model simulations and mapping, and formulate hypotheses on thresholds and spatial locations beyond which dryland mechanisms are expected to operate in non-xeric ecosystems. Notably, for dryland mechanisms to get activated elsewhere there is no need for non-xeric biomes to become actual drylands. With a globally increasing area exposed to gradually rising temperatures, moderate decline in precipitation, and increasing frequency, duration and intensity of extreme heat and drought events, we envision that dryland mechanisms will increasingly control ecosystem functioning in many regions of the world.
Influence of the stratospheric shrinkage on the detected CCMI simulation trends
Authors: Pisoft Petr , Šácha Petr
Published: March 2020

There is a well-established observational evidence that the tropopause is shifting upward. More generally, warming of the troposphere is directly connected with a positive trend of geopotential of pressure levels in the troposphere, which reaches its maximum around the tropopause. In the stratosphere, the geopotential height trends are affected by the stratospheric cooling resulting in a gradual reduction of the upward shift and even its reversal in the upper stratosphere. That leads to a decreasing trend of the stratospheric thickness - a so-called stratospheric shrinkage. In GCMs, shrinkage is one of the strongest and most robust fingerprints of the changing climate. In this study, we investigate the question whether the shrinkage presents additional dynamical feedback influencing other detected trends in the middle atmosphere (besides the influence of vertical shift). Analyzing set of CCMI models, we compute inter-model correlations of shrinkage with trends of various variables to separate the possible shrinkage effect, which is otherwise a non-local function of the temperature.
Status and challenges of FAIR data principles for a long-term repository
Authors: Trabant Chad , Benson Rick , Casey Rob , Sharer Gillian , Carter Jerry
Published: March 2020

The data center of the National Science Foundation’s Seismological Facility for the Advancement of Geoscience (SAGE), operated by IRIS Data Services, has evolved over the past 30 years to address the data accessibility needs of the scientific research community.  In recent years a broad call for adherence to FAIR data principles has prompted repositories to increased activity to support them. As these principles are well aligned with the needs of data users, many of the FAIR principles are already supported and actively promoted by IRIS.  Standardized metadata and data identifiers support findability. Open and standardized web services enable a high degree of accessibility. Interoperability is ensured by offering data in a combination of rich, domain-specific formats in addition to simple, text-based formats. The use of open, rich (domain-specific) format standards enables a high degree of reuse.  Further advancement towards these principles includes: an introduction and dissemination of DOIs for data; and an introduction of Linked Data support, via JSON-LD, allowing scientific data brokers, catalogers and generic search systems to discover data. Naturally, some challenges remain such as: the granularity and mechanisms needed for persistent IDs for data; the reality that metadata is updated with corrections (having implications for FAIR data principles); and the complexity of data licensing in a repository with data contributed from individual PIs, national observatories, and international collaborations.  In summary, IRIS Data Services is well along the path of adherence of FAIR data principles with more work to do. We will present the current status of these efforts and describe the key challenges that remain.
Nonlinear time series models for the North Atlantic Oscillation
Authors: Hannachi Abdel , Önskog Thomas , Franzke Christian
Published: March 2020

The North Atlantic Oscillation (NAO) is the dominant mode of climate variability over the North Atlantic basin and has a significant impact on seasonal climate and surface weather conditions. This is the result of complex and nonlinear interactions between many spatio-temporal scales. Here, the authors study a number of linear and nonlinear models for a station-based time series of the daily winter NAO index. It is found that nonlinear autoregressive models including both short and long lags perform excellently in reproducing the characteristic statistical properties of the NAO, such as skewness and fat tails of the distribution and the different time scales of the two phases. As a spinoff of the modelling procedure, we are able to deduce that the interannual dependence of the NAO mostly affects the positive phase and that timescales of one to three weeks are more dominant for the negative phase. The statistical properties of the model makes it useful for the generation of realistic climate noise.
Seismic activity rate of Mars, based on 420 Sols of InSight data
Authors: Stähler Simon C. , Knapmeyer Martin , Giardini Domenico , Clinton John , Pike Tom , Lognonné Philippe , Panning Mark , Böse Maren , Ceylan Savas , Charalambous Constantinos , van Driel Martin , Horleston Anna , Kawamura Taichi , Kedar Sharon , Khan Amir , Scholz John-Robert , Banerdt Bruce
Published: March 2020

We present an updated estimate of the seismic activity rate of Mars after seven months of high-quality recording of the InSight SEIS instrument. The instrument has been deployed fully on Sol 60 (February 2, 2019) and has been recording with excellent performance since then. The first distant marsquake was observed on Sol 105 (March 14), the first local event on Sol 128 (April 7). From then until early January 2020 (Sol 400), 23 likely events and another 13 candidate events have been observed. Due to a strong diurnal variation in background noise and the generally low magnitude of the activity (compared to Earth), events have been observed only in few low-noise periods of the day. The change of seasons varied the duration of these low-noise periods over the mission, with a magnitude and time-dependent effect on detectability of events and the quantitative estimation of event rates and moment release.

We present a statistical analysis of the global seismic activity level based on a preliminary seismic magnitude model, weighted by the temporal evolution of the ambient noise over half a Martian year. The resulting number of events smaller magnitude 3 is roughly consistent with the pre-mission estimate of Golombek (1992) and the medium model of Knapmeyer et al. (2006), however, as of now, there is a statistically significant lack of events above magnitude 3.5. This hints at a distribution that is skewed towards smaller events, compared to terrestrial global averages.
Land Surface High Temperature Monitoring in Belt and Road Communities
Authors: Xu Ronghan
Published: March 2020

Heatwaves are extended periods of extremely hot weather and high temperature that have a major impact on human health, socioeconomics and natural systems. As predicted by climate models, ongoing global warming will potentially increase the incidence, intensity and duration of summertime heatwave events. Nevertheless, heat-related health impacts are largely preventable if populations, health and social care systems and public infrastructure are prepared. Therefore, this is plausible if heatwave events are studies for which heatwave real-time monitoring and assessment are central components. It is well recognized that land surface temperature retrieved by satellite sensors is an important variable associated with heatwaves and surface warming research. Land surface temperature retrieved by satellite sensors can be observed spatially and temporally, adequate for applications needing real-time and continuous measurements in quick response. In this study, Chinese Fengyun satellite data were used to monitor the land surface thermal environment during the heatwave event in Belt and Road communities. Split-window algorithm were applied to retrieve land surface temperature from thermal sensor. Spatial temporal distributions of Land surface high temperature are monitored in West Europe, India, and Australia as examples during their high temperature weather. The result shows that monitoring the real-time heatwave hazards in quick responds help provided information to the decision makers and get insight into the thermal environment characteristics over urban areas.
Hidden water fluxes in a Mediterranean ecosystem: new insights into seasonal dynamics from lysimeter data
Authors: Paulus Sinikka , El-Madany Tarek , Wutzler Thomas , Orth René , Perez-Priego Oscar , Reichstein Markus , Carrara Arnaud , Moreno Gerardo , Migliavacca Mirco
Published: March 2020

Surface water dynamics can impact ecosystem functioning, in particular in seasonally water-limited regions. The potential importance of dew and other non-precipitation water sources have long been recognized in arid biomes, however, their quantification is uncertain as the collection of precise data of these water sources has been difficult with typical measurement techniques.

The recent development of high precision shear-stress cells and validated data processing methods enables to detect water fluxes of 0.01 mm at the resolution of minutes from precision lysimeters. Thus, they outperform classical measurement devices like rain gauges and eddy covariance (EC) measurements regarding their accuracy in inferring dewfall or night-time evapotranspiration.

In this study, we analyze multiple (non-)precipitation water flux components with respect to their relative importance and corresponding inter-annual dynamics based on large high precision lysimeters. This is done in a Mediterranean tree-grass ecosystem.

Specifically, we concurrently analyze several years of lysimeter data with meteorological data and characterize how the different components of the water cycle respond in time to meteorological drivers and vegetation properties. The study is conducted at the experimental site Majadas de Tietar, Extremadura, Spain. Our results show that the fraction of non-precipitation water can account for more than half of the ecosystems water input during the dry months. We further investigate the micro-meteorological dimension of these processes in this ecosystem and changes of the flux components under exceptionally wet and dry years.

This study contributes to recent efforts to better understand the role of non-precipitation water sources in seasonally water-limited ecosystems of high seasonal precipitation dynamics. Furthermore, this investigation underlines the necessity to raise awareness of the limitations of EC and rain gauge devices in precisely quantifying all water fluxes.
Nitrogen dynamics measurements in wetland soils
Authors: Horváth-Szabó Kata , Grosz Balázs , Ringer Marianna , Szalai Zoltán
Published: March 2020

Wetlands are important sites for the biogeochemical cycles of macro and microelements, because the presence of the water induces faster chemical and transport processes in the soils which occur as intensive diurnal and seasonal fluctuations of the soil parameters and element-content. Vegetation is also varied basically because of the (often fluctuating) water level, which makes it possible to study these different ecotopes in a relatively small area.

We chose our long-term study site – a meadow formed by a local depression of the surface – near Ceglédbercel, Hungary in 2010. Three different vegetation patches were separated governed by the following species (in order of the influence of water): 1 – Agrostis stolonifera; 2 – Carex acutiformis, Carex flacca, Carex vulpina; 3 – Phragmites australis. Microclimatic and soil-representing parameters were measured in each patch: air temperature, evaporation, strength of wind and incident solar radiation; soil temperature, pH and redox potential of the soil solution. We also analyzed the main elements and element forms of the soil solution regularly: NO3-, NO2-, NH4+, PO43-, Mn, Fe, K, Na, Mg, Ca and emitted N2O, CH4 gas fluxes of the soil.

Our main hypothesis was that different plant species generate measurable differences and heterogeneities in the bulk soil. This is shown best by the run of the redox potential which often seemed to ignore the effect of water-gradient because of the regulating ability of plants in the rooting zone. The occurrence and concentration of nitrogen forms are very redox-sensitive; thus they are seemingly good indicators of the state of the soil. Somewhat surprisingly, diurnal cycles (caused by the plants’ alternating photosynthetic activity) rarely occurred among the measured parameters and concentrations. One of those rare occurrences was the emission of gaseous N2O, which reached its maximum in the afternoon and almost stopped before dawn. Our long-term experimentation also caught some interesting anomalies (e. g. accidental destruction of the vegetation) thus we managed to record the effect of these environmental changes on the soil and the most environment-sensitive elements of the soil proved to be the nitrogen-forms, with Fe and K.
e-infrastructures and natural hazards. The Center of Excellence for Exascale in Solid Earth (ChEESE)
Authors: Folch Arnau , de la Puente Josep , Sandri Laura , Halldórsson Benedikt , Fichtner Andreas , Gracia Jose , Lanucara Piero , Bader Michael , Gabriel Alice-Agnes , Macías Jorge , Lovholt Finn , Fournier Alexandre , Monteiller Vadim , Laforet Soline
Published: March 2020

The Center of Excellence for Exascale in Solid Earth (ChEESE; https://cheese-coe.eu) is promoting the use of upcoming Exascale and extreme performance computing capabilities in the area of Solid Earth by harnessing institutions in charge of operational monitoring networks, tier-0 supercomputing centers, academia, hardware developers and third parties from SMEs, Industry and public-governance. The scientific challenging ambition is to prepare 10 European open-source flagship codes to solve Exascale problems on computational seismology, magnetohydrodynamics, physical volcanology, tsunamis, and data analysis. Preparation to Exascale is considering code inter-kernel aspects of simulation workflows like data management and sharing following the FAIR principles, I/O, post-process and visualization. The project is articulated around 12 Pilot Demonstrators (PDs) in which flagship codes are used for near real-time seismic simulations and full-wave inversion, ensemble-based volcanic ash dispersal forecasts, faster than real-time tsunami simulations and physics-based hazard assessments for earthquakes, volcanoes and tsunamis. This is a first step towards enabling of operational e-services requiring of extreme HPC on urgent computing, early warning forecast of geohazards, hazard assessment and data analytics. Additionally, and in collaboration with the European Plate Observing System (EPOS), ChEESE will promote and facilitate the integration of HPC services to widen the access to codes and fostering transfer of know-how to Solid Earth user communities. In this regard, the project aims at acting as a hub to foster HPC across the Solid Earth Community and related stakeholders and to provide specialized training on services and capacity building measures.
Current sheet structure close to a reconnection point observed by MMS
Authors: Rojas Castillo Diana , Nakamura Rumi , Nakamura Takuma K.M.
Published: March 2020

The typical picture of magnetic reconnection in the magnetosphere includes a classic Harris-type current sheet, where the current density is maximum at the magnetic equator (Bx=0). However, observations have shown that the magnetotail current sheet structure is much more complicated than this simple view. Therefore, revealing the structure of the current sheet is of importance to understand the reconnection process. Based on the four-point MMS high-resolution data, we present observations of a multiple reconnection event for which we study the structure of the current sheet as well as some of its characteristic scales. We show that the CS structure is highly dynamic during the reconnection process, changing from a bifurcated shape away from the reconnection site, to a more symmetric (Harris-type) structure near the X-line.