bluuebunny/crossref_metadata_2025 huggingface dataset:
Adria microplate fragmentation: geophysical perspective
Authors: Stipčević Josip , Belinić Tena , Kolínský Petr , Herak Marijan , Molinari Irene , Dasović Iva
Published: March 2021

Adriatic microplate (Adria) has been a major component of the central Mediterranean geodynamic history since at least Late Cretaceous time. Although Cenozoic motion of Adria is relatively well established, there remains several open questions regarding its dynamics. This is especially evident when trying to reconstruct the motion of Adria since early Miocene. Although there is a general consensus about the counterclockwise rotation of Adria with respect to Europe, the amount of this rotation is still a matter of vigorous debate. In order to explain various measurements, several models of Adria motion were introduced: 1) Adria moving in conjunction with Africa, 2) Adria moving independently as a single block and 3) Adria moving independently but divided into two fragments.

Here we explore the third model by using data from temporary seismic station deployments (AlpArray and AlpArray-CASE) and available permanent stations surrounding the Adriatic Sea. We constructed the tomography image of the Adriatic Sea region using the interstation surface wave dispersion measurements from teleseismic events. Additionally, we test the properties of the Central Adriatic crust by analyzing P-receiver functions from mid-Adriatic island seismic stations. Preliminary results show anomalous lithospheric structure in the Central Adriatic dividing Adria into two sections thus indicating that Adria fragmentation has progressed all the way to the base of the lithosphere. 
Hayabusa2 returned samples: first analyses from the MicrOmega/curation investigation 
Authors: Bibring Jean-Pierre , Okada Tatsuaki , Pilorget Cédric , Yogata Kasumi , Brunetto Rosario , Riu Lucie , Hamm Vincent , Nakato Aiko , Hatakeda Kentaro , Loizeau Damien , Yada Toru , MicrOmega team and the
Published: March 2021

The JAXA Hayabusa2 mission has very impressively collected and returned more than 5 g of samples from the C-type Ryugu asteroid early December, 2020, all presently secured within the Extraterrestrial Sample Curation Center at ISAS, Sagamihara, Japan. Their characterization is being performed, using an optical microscope, a FTIR point spectrometer and MicrOmega, a hyperspectral microscope acquiring from each 22 µm pixel of its 256x250 pixels FOV, the full spectrum from 0.99 to 3.6 µm (+ 4 additional visible spectral channels, at 595, 643, 770 and 885 nm). Preliminary results acquired with MicOmega will be presented, and their interpretation discussed.
Analyze the retention characteristics of green roofs.
Authors: Hong Xiang Feng
Published: March 2021

Due to the expansion of the urban area increases the impervious area and Inhibits the influence of evapotranspiration and infiltration of the water cycle. In addition, climate change causes extreme rainfall events, increase rainfall have greatly increased surface runoff in cities, Increase the intensity and depth of rainfall. These have led to a substantial increase in surface runoff in cities.

Green roof is one of the low-impact development measures. This study will improve the above-mentioned problems through the rainfall retention characteristics of green roofs, Calculate peak flow reduction and delay of arrival time. We have built a green roof observation system which including experimental group (green roof) and control group (no green roof) to obtain various observational data of the water cycle. Then input the data into the surface hydrological model for calibration and validation to analyze the retention characteristics of green roofs. Evaluate the flood reduction effect of green roofs in Taiwan.
Tracing North Atlantic Oscillation Forecast Errors to Stratospheric Origins, with a new analysis of the 2021 winter
Authors: Kolstad Erik W. , Wulff C. Ole , Domeisen Daniela , Woollings Tim
Published: March 2021

The North Atlantic Oscillation (NAO) is the main driver of weather variability in parts of Eurasia, Greenland, North America, and North Africa on a range of time scales. Successful extended-range NAO predictions would equate to improved predictions of precipitation and temperature in these regions. It has become clear that the NAO is influenced by the stratosphere, but because this downward coupling is not fully reproduced by all forecast models the potential for improved NAO forecasts has not been fully realized. Here, an analysis of 21 winters of subseasonal forecast data from the European Centre for Medium-Range Weather Forecasts monthly forecasting system is presented. By dividing the forecasts into clusters according to their errors in North Atlantic Ocean sea level pressure 15-30 days into the forecasts, we identify relationships between these errors and the state of the stratospheric polar vortex when the forecasts were initialized. A key finding is that the model overestimates the persistence of both the negative NAO response following a weak polar vortex and the positive NAO response following a strong polar vortex. A case in point is the sudden stratospheric warming in early 2019, which was followed by five consecutive weeks of an overestimation of the negative NAO regime. A consequence on the ground was temperature predictions for northern Europe that were too cold. In this talk, we include a new analysis of the temperature prediction performance following the January 2021 sudden stratospheric warming. Another important finding is that the model appears to misrepresent the gradual downward impact of stratospheric vortex anomalies. This result suggests that an improved representation and prediction of stratosphere-troposphere coupling in models might yield substantial benefits for extended-range weather forecasting in the Northern Hemisphere midlatitudes.
Deep seated gravitational slope deformation north of the Tungnakvíslarjökull outlet glacier, in western Mýrdalsjökull ice cap, S-Iceland
Authors: Saemundsson Thorsteinn , Einarsson Pall , Geirsson Halldor , Belart Joaquin , Hjartardottir Asta Rut , Magnusson Eyjolfur , Palsson Finnur , Pedersen Gro , Drouin Vincent , Ben-Yehoshua Daniel
Published: March 2021

A large deep seated gravitational slope deformation has been detected in a mountain slope north of the Tungnakvíslarjökull outlet glacier, in the western part of the Mýrdalsjökull ice cap in South Iceland. Mýrdalsjökull also hosts the Katla central volcano, which erupted spectacularly last in 1918. Based on comparison of Digital Elevation Models (DEMs) obtained from aerial photographs, lidar and Pléiades stereoimages, the slope has been showing slow gravitational slope deformation since 1945 to present. The total vertical displacement in 1945-2020 is around 200 m. The deformation rate has not been constant over this time period and the maximum deformation occurred between 1999 and 2004 of total of 94 m or about 19 m/year.

The mountain slope north of the Tungnakvíslarjökull outlet glacier reaches up to around 1100 m height. The head scarp of the slide, which is almost vertical, is around 2 km wide rising from about 400-500 m in the western part up to the Mýrdalsjökull glacier at 1100 m in the east. The area of deformation, from the head scarp down to the present-day ice margin is around 1 km2. The total volume of the moving mass is not known as the depth of the sliding plane is not known, but the minimum mobile rock volume is between 100 to 200 million m3. The entire slope shows signs of displacement and is heavily fractured. Continuous GNSS stations which were installed in the uppermost part of the slope in August 2019 and in the lower part of the slope in 2020 provide real-time displacements. The GNSS time series show evidence of seasonal motion of the landslide, with highest deformation rates occurring in late summer or fall. Historically, seismicity in the area has been at maximum in the fall, although little seismicity has been observed since the GNSS stations were installed.

There are two main ideas of the causes for this deformation. One is the consequences of slope steepening by glacial erosion, followed by unloading and de-buttressing due to glacial retreat. Another proposed cause for the deformation is related to its location on the western flank of the Katla volcano. Persistent seismic activity in this area for decades may be explained by a slowly rising cryptodome into the base of the slope, which may also explain the slope failure.
Evolution of Large Bedrock Landslides in the South-Central Andes of NW Argentina 
Authors: M.Aref Mohammad , Bookhagen Bodo , R. Strecker Manfred
Published: March 2021

Deep-seated, slow moving bedrock landslides are significant natural disasters with severe socio-economic repercussions. During the past decades, an acceleration of these hazards has been reported globally due to changes in seasonal freeze-thaw cycles, permafrost thawing, infrastructure development and other anthropogenic sources, changes of precipitation and groundwater levels, and variation in seismic activity. Interferometric Synthetic Aperture Radar(InSAR) is a powerful tool to map landslides movement from space and the Sentinel 1 C-band radar mission provides a high temporal resolution data source to investigate seasonal and intra-annual changes of landslide behaviour.

To construct a 2D/3D displacement field, we decompose a combination of different look angles and InSAR ascending and descending tracks of different sensors including Sentinel and ALOS 1 PALSAR data. The ionospheric delay for InSAR observations is estimated with a split range-spectrum technique because significant ionospheric total electron content variation is common in our study area in the Central Andes. Both statistical phase-based and weather model estimation approaches are implemented to minimize the effect of tropospheric signal on InSAR observations.

Our observations identify several areas with rapid translational slide movements exceeding 5-10 cm/y. Multi-annual and inter-annual behaviour of deformation is extracted through time series analysis and a hierarchical clustering approach is used to identify geographic areas with similar characteristics and rates. We show the wide-spread spatial distribution of unstable hill slopes in the Eastern Cordillera of the south-central Andes, especially at high elevations where field observations are difficult. We identify driving forces to be a combination of pre-existing geologic structures and climatic parameters.
Operational implementation of the smoke forecasting capability in the RAP/HRRR numerical weather prediction system
Authors: Ahmadov Ravan , James Eric , Grell Georg , Alexander Curtis , McKeen Stuart
Published: March 2021

Since December, 2020 NOAA’s operational Rapid Refresh and High-Resolution Rapid Refresh (RAP/HRRR) numerical weather prediction modeling systems include smoke forecasting capability. In RAP/HRRR-Smoke primary aerosols (smoke) emissions from wildland fires are simulated by ingesting the fire radiative power data from the VIIRS (onboard S-NPP and NOAA-20) and MODIS (Terra and Aqua) satellite instruments in real time. I will describe the development and applications of the RAP and HRRR-Smoke models, which cover 3 domains – North America (at 13.5 km spatial gridding), CONUS and Alaska (3km resolution). I will present the applications of these models to forecast smoke distributions on regional and continental scales, and how adding the smoke direct feedback capability can improve weather and visibility forecasting. The RAP/HRRR-Smoke models are the first operational weather models in the US, which include the impact of the smoke aerosols on weather and visibility forecasting. The verification of the HRRR-Smoke model for July-August 2018 over the CONUS domain using various meteorological and aerosol measurements will be presented. For verification of the fire plume injection height simulations in HRRR-Smoke, we use the aircraft lidar and in-situ measurements from the FIREX-AQ campaign during August 6-8, 2019. Finally, I will discuss the future plans for improving forecasting of smoke-weather interactions in coupled air quality models.
Ion energy and momentum flux near the cometopause of Comet 67P/Churyumov-Gerasimenko
Authors: Williamson Hayley , Nilsson Hans , Moslinger Anja , Bergman Sofia , Stenberg-Wieser Gabriella
Published: March 2021

Defined as the region where the plasma interaction region of a comet goes from being solar wind-dominated to cometary ion-dominated, the cometopause is a region of comingling plasmas and complex dynamics. The Rosetta mission orbited comet 67P/Churyumov-Gerasimenko for roughly two years. During this time, the cometopause was observed by the Ion Composition Analyzer (ICA), part of the Rosetta Plasma Consortium (RPC), before and after the spacecraft was in the solar wind ion cavity, defined as the region where no solar wind ions were measured. Data from ICA shows that solar wind and cometary ions have similar momentum and energy flux moments during this transitional period, indicating mass loading and deflection of the solar wind. We examine higher order moments and distribution functions for the solar wind and cometary species between December 2015 and March 2016. The behavior of the solar wind protons indicates that in many cases these protons are deflected in a sunward direction, while the cometary ions continue to move predominately antisunward. By studying the distribution functions of the protons during these time periods, it is possible to see a non-Maxwellian energy distribution. This can inform on the nature of the cometopause boundary and the energy transfer mechanisms at play in this region.
S-wave velocity structure in the central Japan derived from adjoint tomography.
Authors: Mukumoto Kota , Tsuji Takeshi
Published: March 2021

In Japan, seismic velocity structures have been estimated by using first arrival tomography method. Many significant crustal structures such as the coordinate of the subducted Philippine Sea plate has been revealed by seismic tomographic images. In this study, we applied the adjoint tomography including full numerical simulation and finite frequency sensitivity kernels for the area of central Japan. The study area is characterized by the very heterogeneous geologic structures. We used 72 natural earthquakes in this study. Because the dominant phase used in our analysis is the surface wave, only S-wave velocity was inverted. We tried to minimize the time-frequency phase misfit between observed and calculated waveforms with the frequency of 0.033~0.1Hz. Based on the checker bord test, our inversion scenario resolved the upper and lower crust. From the results, we identified more heterogeneous structures compared to those from the first arrival tomography. The estimated S-wave velocity model clearly resolved the low velocity anomalies around the active volcanoes. Furthermore, the velocity boundaries agree with the main tectonic lines in the central Japan.
The integration of element cycles: contrasting perspectives from natural and managed systems in global change research
Authors: Buckeridge Kate
Published: March 2021

Despite the ecological connection between natural and managed systems, they are often studied separately, by different research groups. This echoes the focus of this session that, despite the tight coupling of carbon (C) and nitrogen (N), global change investigations of these element cycles may be carried out by different research groups. This talk will address the contrasting approach to integrating element cycles between researchers in natural and managed systems.

Global change research in natural systems has focused on predicting the C balance of the system. Integrating research between C and other element cycles makes sense in this situation, because the growth and activity of the research organisms (animals, plants, microorganisms) are limited by other elements. This stoichiometric theory (multiple limitation hypothesis) has been investigated for at least three decades, and although C and other elements are often studied independently, many researchers in natural systems have embraced this elemental integration in their global change research. 

Managed systems also have a long history of element limitation research, primarily NPK, with a focus on maximising plant growth and the economy of fertiliser use efficiency. However, natural climate solutions - necessary because mandatory reductions in fossil fuel emissions are insufficient to meet climate targets – often rely on sequestering C in biomass and soils, changing the focus of managed system research to include C. As we know from our research in natural systems, the process of C sequestration is tightly coupled to N (and other elements). Unfortunately, most soil C process models or earth system models do not include N (or other elements). Very few soil C sequestration predictions include the C-cost of N2O losses - an important trade-off in N-saturated systems - primarily because there has been insufficient research into the microbial interdependency of C and N in managed soils.

In this talk I will discuss recent insights into how the integration of C and N (and other elements) in the ecological research of managed systems can improve our ability to mitigate the consequences of global change.
3D Remote Sensing of Trace Gas Distributions with HAIDI (Heidelberg Airborne Imaging DOAS Instrument) - Power Plant and Ship Emissions observed during the EMeRGe Campaigns
Authors: Bigge Katja , Frieß Udo , Pöhler Denis , Platt Ulrich
Published: March 2021

Compared to ground-based or satellite measurements, atmospheric observations based on aircraft missions have many advantages, such as the potential to observe a large atmospheric volume using remote sensing measurements, among which Differential Optical Absorption Spectroscopy (DOAS) is a well established method for the observation of integrated trace gas concentrations along the light path. However, the interpretation of remote spectroscopic measurements using scattered sunlight is complicated due to the lack of prior knowledge on the light paths between sun and detector, and thus on the observed air volume. Using radiative transfer calculations, quantities commonly derived from DOAS measurements are integrated vertical columns of various trace gases, providing no information about their vertical distribution.

On the ground, tomographic approaches have been used to reconstruct the spatial distribution of trace gases by using multiple viewing directions and detectors. HAIDI, the Heidelberg Airborne Imaging DOAS Instrument, was designed to transfer this concept to the air. In addition to its excellent temporal and spatial resolution (40 m x 40 m at 1.5 km flight altitude, 266 m x 266 m at 10 km flight altitude, at 10 ms temporal resolution), HAIDI uses three separate scanning telescopes aimed at +/-45° forward- and backward looking angles and the nadir direction. In combination with a 3D radiative transfer model, this allows a reconstruction of the 3D distribution of the detected trace gases in the vicinity of the flight track.

HAIDI joined the EMerGe (Effect of Megacities on the Transport and transformation of Pollutants on the Regional to Global Scales) missions on HALO, the High Altitude and LOng range research aircraft based at DLR (German Aerospace Center) in Oberpfaffenhofen, Germany. The EMerGe missions targeted the emission outflows of megacities to investigate their compositions and the atmospheric impact of urban pollution in Europe (July 2017) and Asia (March 2018). HAIDI observed a number of trace gases such as NO2, SO2 and HCHO. For NO2 and SO2 in particular, strong plumes originating from power plants and ships were found, which were then used for inversion of the 3D distribution of the plume and emission estimation. Here we present the method and results of the HAIDI measurements during the EMeRGe missions.
Multiscale analysis of a current sheet embedded in a fast earthward flow during a substorm event detected by MMS
Authors: Le Contel Olivier , Retino Alessandro , Alexandrova Alexandra , Nakamura Rumi , Alqeeq Soboh , Chust Thomas , Mirioni Laurent , Catapano Filomena , Jacquey Christian , Toledo Sergio , Stawarz Julia , Goodrich Katherine , Gershman Daniel J. , Fuselier Stephen A. , Mukherjee Joey , Ahmadi Narges , Graham Daniel , Argall Matthew , Fischer David , Huang Shiyong ,   MMS team
Published: March 2021

In July 2017, the MMS constellation was evolving in the magnetotail with an apogee of 25 Earth radii and an average inter-satellite distance of 10 km (i.e. at electron scales). On 23 rd of July around 16:19 UT, MMS was located at the edge of the current sheet which was in a quasi-static state. Then, MMS
suddenly entered in the central plasma sheet and detected the local onset of a small substorm as indicated by the AE index (~400 nT). Fast earthward plasma flows were measured for about 1 hour starting with a period of quasi-steady flow and followed by a saw-tooth like series of plasma jets (“bursty bulk flows”). In the present study, we focus on a short sequence related to an ion scale current sheet crossing embedded in a fast earthward flow. We analyse in detail two other kinetic structures in the vicinity of this current sheet: an ion-scale flux rope and an electron vortex magnetic hole and discuss the Ohm’s law and conversion energy processes.
Evaluation of gridded near surface air temperature datasets across complex terrain 
Authors: Karaman Çağrı Hasan , Akyurek Zuhal
Published: March 2021

Near surface air temperature is a key variable used in wide range of applications showing environmental conditions across the earth. Standard meteorological observations generally provide the best estimation with high accuracy over time for a small area of influence. However, considerable uncertainty arises when point measurements are extrapolated or interpolated over much larger areas. Satellite remote sensing data have emerged as a viable alternative or supplement to in situ observations due to their availability over vast ungauged regions. Thus, spatial patterns of air temperature can be derived from satellite remote sensing.

In this study, we evaluate the performance of several satellite-based products of near surface air temperature to determine the best product in estimating daily and monthly air temperatures. Era5 Land, SMAP Level 4, AgERA5, MERRA2 products are used with 1120 ground-based gauge stations for the period 2015-2019 over complex terrain and different climate classes according to Köppen-Geiger climate classification in Turkey. Moreover, several traditional and more sophisticated machine learning downscaling algorithms are applied to increase products’ spatial resolution. The agreement between ground observations and the different products and the downscaled temperature product is investigated using a set of commonly used statistical estimators of mean absolute error (MAE), correlation coefficient (CC), root-mean-square error (RMSE) and bias.

Performance analysis of satellite-based air temperature products with ground-based observations on monthly time series has shown that ERA5 Land and SMAP L4 products have similar capabilities. However, analysis on daily time series depicted that ERA5 Land is superior to SMAP L4 product. Results indicate that bicubic interpolation performs best on downscaling Era5 Land product daily time series. However, Random Forest algorithm is superior on monthly time series.
New seismotectonic regionalization for Germany: comparison with existing regionalizations
Authors: Spies Thomas , Hahn Tim , Kley Jonas , Kaiser Diethelm
Published: March 2021

We have created a new seismotectonic regionalization for Germany including a 200 km zone around its borders, based on a new concept which initially processes geological information separately from modern seismicity. The identification of a region as a distinct seismotectonic unit is estimated from past deformation, not the present one as represented by earthquakes. This has been done by analyzing fault density and displacements separately for six time slices from 300 Ma to the Present. The final regionalization results from overlaying the six deformation intensity maps and contrasts regions that deformed either repeatedly or very strongly in the geological past with others that suffered very little deformation. The new regionalization is significantly different from existing regionalizations. The existing ones mostly relied on modern seismicity for defining areas while using geological contacts of varying type (surface traces of faults, but also erosional edges of stratigraphic units as represented on geological maps) to trace boundaries.

The new, geology-based regionalization comprises comparatively few regions. Ubiquitous small faults (cm- to m-displacements) in the geological record suggest that earthquakes of low magnitude can occur anywhere and need not be tied to large faults. Our regionalization concurs with earlier ones in identifying the Cenozoic rifts – Upper Rhine Graben, Lower Rhine Graben and Eger Rift – as zones of increased hazard. A 100-150 km wide, NW-SE-trending belt of intense Mesozoic deformation runs across northwestern and central Germany from the Emsland to the Erzgebirge where it bifurcates into two branches that continue along the borders of the Bohemian Massif. This belt coincides reasonably well with the relatively sparse earthquakes in central and northern Germany. The Tornquist Fault Zone running NW-SE from northern Denmark to Bornholm is another belt of increased past deformation and elevated seismic activity on the northeastern border of our region. Areas of particularly low past deformation comprise the Brabant Massif, the Rhenish Massif and Münsterland Basin east of the Lower Rhine Graben, the Alpine foreland south of the Danube river and the Bohemian Massif southeast of the Eger Rift. Earthquake clusters occurring in stable areas such as the Brabant Massif or the Swabian Jura highlight geologically unexpected events. They can be added to the regionalization as separate zones or accounted for via a logic tree. They should not be used to assign increased hazard to the larger regions of the geology-based regionalization.
European daily precipitation according to EURO-CORDEX regional climate models (RCMs) and high-resolution global climate models (GCMs) from the High-Resolution Model Intercomparison Project (HighResMIP)
Authors: Demory Marie-Estelle , Berthou Ségolène ,   PRIMAVERA and EURO-CORDEX co-authors
Published: March 2021

In this study, we evaluate a set of high-resolution (25–50 km horizontal grid spacing) global climate models (GCMs) from the High-Resolution Model Intercomparison Project (HighResMIP), developed as part of the EU-funded PRIMAVERA (Process-based climate simulation: Advances in high resolution modelling and European climate risk assessment) project, and from the EURO-CORDEX (Coordinated Regional Climate Downscaling Experiment) regional climate models (RCMs) (12–50 km horizontal grid spacing) over a European domain. It is the first time that an assessment of regional climate information using ensembles of both GCMs and RCMs at similar horizontal resolutions has been possible. The focus of the evaluation is on the distribution of daily precipitation at a 50 km scale under current climate conditions. Both the GCM and RCM ensembles are evaluated against high-quality gridded observations in terms of spatial resolution and station density. We show that both ensembles outperform GCMs from the 5th Coupled Model Intercomparison Project (CMIP5), which cannot capture the regional-scale precipitation distribution properly because of their coarse resolutions. PRIMAVERA GCMs generally simulate precipitation distributions within the range of EURO-CORDEX RCMs. Both ensembles perform better in summer and autumn in most European regions but tend to overestimate precipitation in winter and spring. PRIMAVERA shows improvements in the latter by reducing moderate-precipitation rate biases over central and western Europe. The spatial distribution of mean precipitation is also improved in PRIMAVERA. Finally, heavy precipitation simulated by PRIMAVERA agrees better with observations in most regions and seasons, while CORDEX overestimates precipitation extremes. However, uncertainty exists in the observations due to a potential undercatch error, especially during heavy-precipitation events.

The analyses also confirm previous findings that, although the spatial representation of precipitation is improved, the effect of increasing resolution from 50 to 12 km horizontal grid spacing in EURO-CORDEX daily precipitation distributions is, in comparison, small in most regions and seasons outside mountainous regions and coastal regions. Our results show that both high-resolution GCMs and CORDEX RCMs provide adequate information to end users at a 50 km scale.
Stochiometric control of SOM and plant derived soil C pools dynamics under elevated CO2  
Authors: Pihlblad Johanna , Andresen Louise C. , Macdonald Catriona , Ellsworth David , Carrillo Yolima
Published: March 2021

Elevated carbon dioxide in the atmosphere (eCO2) has been found to influence soil C by altering the belowground balance between the decomposition of existing soil organic matter (SOM) and the accumulation of plant-derived C inputs. Even small changes in this balance can have a potentially large effect on future climate. The relative availability of soil nutrients, particularly N and P, are crucial mediators of both decomposition and new C accumulation, but both these two processes are rarely assessed simultaneously. We asked if the effect of eCO2 on soil C decomposition was mediated by soil N and P availability, and if the effect of CO2 and soil N and P availability on soil C decomposition was dependent on C pools (existing SOM C, newly added C). We grew Eucalyptus grandis and a C3 grass (Microlaena stipoides) from seed in an experimentally manipulated atmosphere with altered δ13C signature of CO2, which allowed the separation of plant derived C, from the existing SOM C. Then we manipulated N and P relative abundance via nutrient additions. We evaluated how the existing SOM and the new plant-derived C pool, and their respiration responded to eCO2 conditions and nutrient treatments. SOM respiration significantly increased in the eucalypts when N was added but was not affected by CO2. In the grass the SOM respiration increased with eCO2 and added N and SOM respiration per unit of SOM-derived microbial was significantly higher in both the added P and added N+P nutrient treatments. The rhizosphere priming of SOM was suppressed in both the added P and added N+P nutrient treatments. The heterotrophic respiration of plant-derived C was contingent on nutrient availability rather than eCO2 and differed by species. The grass-derived respiration was significantly higher than the eucalypt and was higher in both added P and added N+P nutrient treatments. Thus, nutrient stoichiometry had similar effects on SOM and plant derived C, but e CO2 only affected SOM and only for the Eucalyptus.  This study shows how species differences have large effects on rhizosphere C cycling responses to eCO2 and stoichiometric conditions.      
Mappıng wıth the use of uas. Project plannıng and adjustment: the case of Mersınıdı landslıdes (Chıos Island, NE Aegean)
Authors: Spyrou Nafsika-Ioanna , Stanota Eirini Spyridoula , Andreadakis Emmanuel , Skourtsos Emmanuel , Lozios Stylianos , Lekkas Eyfthymios
Published: March 2021

This project aims at the use of Unmanned Aircraft Systems (UAS) applications for mapping. Geomorphological mapping of features and changes with the use of UAS, in cases of floods, landslides, stream flows, etc. has been growing rapidly in recent years. It is combined with traditional mapping methods as well as modern technologies such as Geographic Information System (GIS). Our work concerns landslide hazard in the study area of Chios, in particular along the Chios - Kardamila road in the Mersinidi - Miliga region with a record of landslides and particular geological interest. During the field survey a) three-dimensional model of the slope was made across the road using UAS and the apropriate software, b) point cloud, c) a mosaic orthophotomap and d) a Digital Surface Model (DSM). After the data collection components material we followed detailed geological and tectonic mapping with enormous accuracy because the innovative technologies provided us multiple data compared to older methodologies. The exploitation of the Structure from Motion provided us with information of the inaccessible parts of the study area.

 
Multi-physics, multi-domain, and multi-scale coupling concept for groundwater to surface-water interactions driving submarine landscape evolution
Authors: Gupta Shubhangi , micallef Aaron
Published: March 2021

Groundwater is an important geomorphic agent, and its interactions with land and surface-water play a critical role in driving landscape evolution through highly coupled and complex processes such as internal erosion, surface erosion, slope failure and debris flows.

From a modelling point of view, a common approach has been to tackle the hydrologic and geomorphic processes separately. To date, the multi-domain and multi-physics interactions across the groundwater – surface-water interfaces remain poorly conceptualized. Furthermore, the groundwater models are typically highly simplified; the effects of thermal fluxes, diagenetic processes, multi-phase transport and phase transitions, density driven flows, etc. are either ignored, or introduced through lumped or reduced models without fully resolving the underlying process couplings. In sediments that are susceptible to chemical weathering, like carbonate rocks, there are almost no known and validated models that can handle evolving pore geometry due to carbonate dissolution in conjunction with internal erosion. Moreover, the saturated and unsaturated groundwater, surface-water, seafloor, and subaerial terrain constitute multiple distinct domains. The interactions across these domains occur at multiple length and time scales, and the landscape evolution results in changing geometries of each domain.

Due to the multi-physics, multi-scale, and multi-domain characteristics of these models, the resulting systems of equations are highly complex, nonlinear, non-standard, and computationally challenging, both in terms of numerical implementation as well as computing resources. These features not only add to the conceptual and numerical complexity, but also demand specialized and targeted solutions.

 Here we present an abstract modular framework to resolve the multi-physics couplings within targeted sub-domains (i.e., 2D/3D sub-surface and1D/2D surface-water, sea-floor and subaerial terrain) and across the domain interfaces. We also introduce an algorithm to handle the changing geometries of these domains. This framework is being developed within the ERC project ‘MARCAN’ and will be used to assess the role of groundwater flow and seepage on the geomorphic evolution of continental margins.
Thermo-mechanical Effects on Fracture Growth and Apertures in Three-Dimensional Subsurface Fractured Rocks 
Authors: Paluszny Adriana , Thomas Robin N. , Saceanu M. Cristina , Zimmerman Robert W.
Published: March 2021

A finite-element based, quasi-static growth algorithm models mixed mode concurrent fracture growth in three dimensions, leading to the formation of non-planar arrays and networks. To model the fully coupled THM model, equations describing mechanical deformation as well as heat transfer in the matrix and in the fractures are introduced in the formulation, simultaneously accounting for the effect of fluid flow and stress-strain response. This results in five separate, but two-way coupled model equations: a thermoporoelastic mechanical model; two fluid flow equations, one for the rock matrix and one for the fractures; two heat transfer equations, similarly for both the matrix and fractures. Fractures are represented explicitly as discrete surfaces embedded within a volumetric domain [1]. Growth is computed as a set of vectors that modify the geometry of a fracture by accruing new fracture surfaces in response to brittle deformation. Fracture tip stress intensity factors drive fracture growth. This growth methodology is validated against analytical solutions for fractures under compression and tension [2]. Thermal effects on the apertures and growth patterns will be presented. Isolated fracture geometries are compared with selected experimental results on brittle media. Accurate growth is demonstrated for domains discretised by refined and coarse volumetric meshes. Fracture and volume-based growth rates are shown to modify fracture interaction patterns. Two-dimensional cut-plane views of fracture networks show how fractures would appear on the surface of the studied volume.

REFERENCES

[1] N. Thomas, A. Paluszny and R. W. Zimmerman. Growth of three-dimensional fractures, arrays, and networks in brittle rocks under tension and compression. Computers and Geotechnics, 2020. doi: 10.1016/j.compgeo.2020.103447

[2] Paluszny and R. W. Zimmerman. Numerical fracture growth modeling using smooth surface geometric deformation. Eng. Fract. Mech., 108, 19-36, 2013. doi: 10.1016/j.engfracmech.2013.04.012
Detection of microplastics in soil samples from the area of traffic route
Authors: Worek Jagoda , Białas Anna , Styszko Katarzyna
Published: March 2021

At the end of the 1940s, mass production of plastics began. Since then, due to the very wide range of applications, a steady increase in their production has been observed. Anthropogenic activities have a significant impact on the natural environment. In this case, despite the knowledge of the problem, as early as the early 1970s, the harmful consequences continued to increase, and even if stopped immediately, their effects would last for centuries. In 2018, global production of plastics reached almost 360 million tonnes. The diverse use of plastics and low production costs mean that there are no other environmentally friendly alternatives that could replace them on a large scale. Therefore, it can be assumed that their production will continue to grow dynamically. The main hazard posed by the production of plastics is microplastic. These are plastic particles smaller than 5 mm. Research on microplastics in the environment is based mainly on diagnosing the problem in sea waters. Its concentration in soils is underestimated. The microparticles of plastics contained in the soil influence not only its structure or the ability to retain water, but also the organisms living in it. In the experiment, soil samples from the vicinity of a busy road in the city of Krakow, Poland, were examined. First, the samples were separated by density, and then the organic material was digested. The separated microplastics were analyzed both in terms of quantity and quality. Tests were carried out under the FTIR microscope, using the sensitive DRIFT method, and in the case of larger fragments, using ATR-FTIR. The results indicated the presence of a large fraction of microplastics, most often from tire abrasion.
Using SlideforMAP and SOSlope to identify susceptible areas to shallow landslides in the Foreste Casentinesi National Park (Tuscany, Italy)
Authors: Murgia Ilenia , Giadrossich Filippo , Niccolini Marco , Preti Federico , Giambastiani Yamuna , Capra Gian Franco , Cohen Denis
Published: March 2021

SlideforMAP and SOSlope are part of a suite of software available through ecorisQ (www.ecorisq.org), an international, non-profit association promoting solutions for risk reduction of natural hazards. SlideforMap is a probabilistic model that quantifies the stabilizing effect of vegetation at the regional scale and localizes potential areas where forest protection could be improved. SOSlope is a hydro-mechanical model that computes the factor of safety at the slope scale, using a strain-step discrete element method, which includes the effects of vegetation root structure and composition. The research aims at investigating the landslide susceptibility at two different spatial scales, using both models. 

The study area is located on a vegetated slope near an interregional connecting road (Tuscany, Emilia-Romagna, central Italy), which crosses the Foreste Casentinesi National Park (Tuscany) an important natural area for both touristic and recreational activities. 

A shallow landslide susceptibility analysis was performed at two different spatial scales, combining the use of the two previously mentioned models. In particular, SlideforMap was applied to identify the main susceptible areas to landslides at regional scale. Next, the identified unstable areas were investigated at detailed scale using SOSlope which simulated an intense rainfall event. Specifically, both distributions of root and soil forces along the slope were analyzed; for the sake of comparison, beech (Fagus sylvatica L.) and spruce (Picea abies L.) parameters were used. Finally, a back-analysis was performed on real landslides. 

The results showed the activation of root reinforcement spatially distributed in the studied slope. The basal root reinforcement map highlights significant differences, with beech showing higher reinforcement values compared to spruce. According to the factor of safety map, landslides may occur along the investigated unstable area. 

SlideforMap and SOSlope may be useful tools to support land and forestry planning, allowing the localization and quantification of the protective effects of forests, root reinforcement included. Results demonstrated that the factor of safety can be used as benchmarks for silvicultural interventions, thus improving the whole planning activities in both forest and surrounding natural and man-made systems.
Impacts of vegetation greenness on the sensitivity of terrestrial ecosystem productivity to flash drought in China
Authors: Zhang Miao , Yuan Xing
Published: March 2021

Vegetation greening in the recent three decades significantly alters the carbon and water cycles over China. The response of terrestrial ecosystem productivity to flash droughts could be influenced by vegetation conditions and characteristics of flash droughts. However, it is still unclear that how the sensitivity of vegetation to flash drought varies with increasing leaf area index (LAI) across China. We use a land surface model and multiple satellite LAI products to assess the response of gross primary productivity (GPP) to flash droughts. Evapotranspiration is increased with increasing LAI and soil moisture is correspondingly decreased. Thus, the frequency, duration, and severity of flash droughts are all intensified from a water-budget perspective. The increasing LAI is contributed to the enhanced terrestrial carbon sink through increasing water use efficiency (WUE). The resistance and resilience of GPP to flash drought are also enhanced due to the increased LAI across various climates and vegetation types. These results refine the sensitivity of GPP to flash droughts in greening China and constrain the prognostic models to simulate the response of vegetation to droughts in changing environments.
Application of the Hydrus 3D model to determine the wet bulb in drip-irrigated soils of intensive greenhouses
Authors: Roldán-Cañas José , Zapata-Sierra Antonio Jesús , Reyes-Requena Rafael , Moreno-Pérez María Fátima
Published: March 2021

Abstract: The development of the wet bulb under drip irrigation in stratified (sand covered soils) presents a different behavior from that observed under homogeneous soils. The presence of a very active crop as it happens in intensive greenhouses also imposes a series of variations that have not been fully characterized. The aim of this work is to present the data acquisition methodology to calibrate and validate the Hydrus-3D model to safely define the evolution of moisture in wet bulbs generated in stratified “sanded” soils characteristic of greenhouses with tomato and pepper crops grown intensively under drip irrigation.

The procedure for collecting and processing moisture data in stratified soils has been defined. The soil and permeability curve has been adjusted experimentally for each material. It has been proved that the Hydrus-3D model can reproduce the behavior of a sand covered soils and it has been possible to verify that the predictions are adequate to what has been observed in the field.
Analyzing the tremor of the Holuhraun eruption 2014-2015 using tremor modelling
Authors: Dietrich Thoralf , Eibl Eva P.S.
Published: March 2021

The 2014-2015 Holuhraun eruption was the largest eruption in Iceland in the last 230 years. After magma ascended below <!-- Gibt es ein Paper das belegt, dass Magmaaufstieg den Dike getriggert hat? Ich denke, das ist eher Spekulation.
Vllt. wäre es besser einfach zu sagen, „From ice-covered Bardarbunga an about 2 week long EQ migration …“ -->the Bárðarbunga volcano’s icecap, an about 2 week long lateral migration of earthquakes was observed; later interpreted as dike formation in 4km to 6km depth. An eruption started on 29th and 31st of August 2014 at Holuhraun. During dike formation and eruption a long-lasting seismic signal called tremor was recorded by seismometers in the area. Eruptive tremor emerged with the onset of the eruptions on 29th and 31st of August . Tremor sources were located and interpreted in the context of the fissure and the lava flow field. However, a complete geophysical model to explain these is missing. Our starting point is the model on tremor generation based on conduit wall vibrations exited by laminar flow (B. Julian 1994) to replicate the observed tremor signals. We performed a grid search and compare it with other models. In the range of rock parameter tolerance, we present implied characteristics of frequency and amplitude of the signals, if the Julian model were used as explanation for the tremor signals.
Contactless and high-frequency optical hygrometry in LACIS-T
Authors: Grosz Robert , Nowak Jakub , Niedermeier Dennis , Mijas Jędrzej , Frey Wiebke , Ort Linda , Malinowski Szymon , Schmalfuss Silvio , Stacewicz Tadeusz , Voigtländer Jeans
Published: March 2021

A narrow-band optical hygrometer FIRH (Fast Infrared Hygrometer, Nowak et al., 2016), based on absorption of laser light at wavelength λ=1364.6896 nm was used for contactless measurements of humidity inside the measurement volume of LACIS-T (turbulent Leipzig Aerosol Cloud Interaction Simulator, Niedermeier et al., 2020). LACIS-T is a multi-purpose moist-air wind tunnel for investigating atmospherically relevant interactions between turbulence and cloud microphysical processes under well-defined and reproducible laboratory conditions. Main goals of the experiment were:

1) characterization and evaluation of the FIRH hygrometer in controlled conditions,

2) characterization of fast turbulent humidity fluctuations inside LACIS-T.

 

Collected results indicate, that FIRH can be used to characterize turbulent fluctuations of humidity in scales of tens of centimeters with the temporal resolution of 2 kHz and presumably more. Interestingly, scanning of LACIS-T measurement volume indicated existence of turbulence and wave-like features for the investigated measurement setup in its  central part, where air streams of different thermodynamical properties, yet the same mean velocity mix intensively. , However, the setup for cloud measurements include an additional flow (i.e., an aerosol flow) in the central part strongly reducing the wave-like features. In other words, cloud process studies are most likely unaffected by these features.

Finally, the experiments proved that contactless measurements of humidity conducted from outside the measurement volume of LACIS-T are useful, on condition of corrections of glass window transmission and interferences.

 

Niedermeier, D., Voigtländer, J., Schmalfuß, S., Busch, D., Schumacher, J., Shaw, R. A., and Stratmann, F. (2020): Characterization and first results from LACIS-T: a moist-air wind tunnel to study aerosol–cloud–turbulence interactions, Atmos. Meas. Tech., 13, 2015-2033, doi:10.5194/amt-13-2015-2020.

Nowak J., Magryta P., Stacewicz T., Kumala W., Malinowski S.P., 2016: Fast optoelectronic sensor of water concentration, Optica Applicata, vol. 46(4) , pp. 607-618 , doi: 10.5277/oa160408