bluuebunny/crossref_metadata_2025 huggingface dataset:
Structural controls on the emplacement and evacuation of magma from a sub-volcanic laccolith: Reyðarártindur Laccolith, SE Iceland
Authors: Twomey Vincent , McCarthy William , Magee Craig
Published: March 2021

Laccoliths play a significant role in the transport and storage of magma in sub-volcanic systems. The construction and geometry of laccoliths can influence host rock and surface deformation patterns that may precede and provide warning of active magmatism and impending eruptions. Yet how laccolith construction and internal magma dynamics controls the location and form of magma ascent conduits (e.g., dykes and inclined sheets), which facilitate magma evacuation and may feed volcanic eruptions, remains poorly documented in natural examples.

The excellently exposed silicic, sub-volcanic Miocene Reyðarártindur Laccolith in SE Iceland offers an opportunity to investigate how magma ascent within inclined sheets, which emanated from the laccolith, related to intrusion construction and deformation in the surrounding host rock. We combine detailed structural mapping with anisotropy of magnetic susceptibility (AMS) analyses, which allow us to map magnetic rock fabrics that reflect magma flow patterns, to show that the laccolith comprises of several distinct magma lobes that intruded laterally towards the south-west. Each lobe intruded, inflated, and coalesced along a NE-SW primary axis facilitated by doming (i.e., forced folding) of the host rock. We also shown that pre-existing NNE-striking, left-stepping, en-echelon fault/fractures, as well as those generated during intrusion-induced host rock uplift, host moderately to steeply inclined rhyolitic/granophyric sheets that emanate from the lateral terminations of some flow lobes.

Based on the observed geometrical relationships between AMS fabrics and the sheet margins where magnetic foliations subparallel sheet contacts, or characterize an imbrication fabric, we suggest that magma evacuated moderately to steeply upward via these fault/fracture-controlled sheets. As these inclined sheets dip towards the laccolith, any eruptions they may have fed would have been laterally offset from the laccolith and any overlying surface deformation driven by forced folding. Our study shows that magma evacuation and ascent from laccoliths can be facilitated by inclined sheets that form at the lateral terminations of magma lobes that are spatially controlled by laccolith construction (e.g., flow direction and doming of the host rock) and the presence of pre-existing structures.
Methane fluxes from Zambian tropical wetlands
Authors: Shaw Jacob , Allen Grant , Barker Patrick , Pitt Joseph , Lee James , Bauguitte Stéphane , Pasternak Dominika , Bower Keith , Daly Michael , Lunt Mark , Ganesan Anita , Vaughan Adam , Fisher Rebecca , France James , Lowry David , Palmer Paul , Bateson Prudence , Nisbet Euan
Published: March 2021

Airborne measurements of methane (CH4) were recorded over three major wetland areas in Zambia in February 2019 during the MOYA (Methane Observations and Yearly Assessments) ZWAMPS field campaign. Enhancements of up to 600 ppb CH4 were measured over the Bangweulu (11°36’ S, 30°05’ E), Kafue (15°43’ S, 27°17’ E), and Lukanga (14°29’ S, 27°47’ E) wetlands. Three independent methods were used to quantify methane emission fluxes; aircraft mass balance, aircraft eddy covariance, and atmospheric inversion modelling. Results yielded methane emission fluxes of 10-20 mg CH4 m-2 hr-1, which were up to an order of magnitude greater than the emission fluxes simulated by various wetland process models (WetCHARTs ensemble and LPX-Bern). Independent column CH4 observations from the TROPOMI instrument were used to verify these fluxes, and investigate their applicability for timescales longer than the duration of the MOYA flight campaign.
Better downscaling results for the right reasons - A process based evaluation of the ICAR model
Authors: Horak Johannes , Hofer Marlis , Gohm Alexander , Rotach Mathias W.
Published: March 2021

The evaluation of models in general is a non-trivial task. Even a well established model may yield correct results for the wrong reasons, i.e. by a different chain of processes than found in observations. While guidelines and strategies exist to maximize the chances that results match measurements for the right reasons, these are mostly applicable to full-physics models, such as numerical weather prediction models. The Intermediate Complexity Atmospheric Research (ICAR) model is a comparatively novel atmospheric model employed to downscale atmospheric fields. ICAR uses linear mountain wave theory to represent the wind field and advects atmospheric quantities, such as temperature and moisture in this wind field. Additionally a microphysics scheme is applied to represent the formation of clouds and precipitation.

We conducted an in-depth process-based evaluation of ICAR, employing idealized simulations to increase the understanding of the model and develop recommendations to improve its results. We contrast the ICAR simulations to Weather Research and Forecasting (WRF) model simulations and asses the impact of our recommendations with a case study for the South Island of New Zealand.

Our results suggest two key aspects relevant for ICAR to obtain the correct results for the right reasons. Firstly, the representation of the wind field within the domain improves when the dry and the moist Brunt-Väisälä frequencies are calculated in accordance to linear mountain wave theory from the unperturbed base state rather than from the time-dependent perturbed atmosphere. Secondly, the results show that there is a lowest possible model top elevation that should not be undercut to avoid influences of the model top on cloud and precipitation processes within the domain. We analysed the causes for the differences between the idealized ICAR and WRF simulations and attribute them to the non-linearities in the WRF wind field and additional simplifications in the governing equations of ICAR. With our recommended ICAR setup applied to the real case study we find an upwind spatial shift of the precipitation maximum in comparison to the results obtained with the original ICAR setup. Additionally our results show that when model skill is evaluated from statistical metrics based on comparisons to surface observations only, such analysis may not reflect the skill of the model in capturing atmospheric processes such as gravity waves and cloud formation.

Overall our findings have consequences for the interpretation of past results obtained with ICAR and suggest improvements to ICAR in future studies.
Electromagnetic Proton Beam Instabilities in the Inner Heliosphere: Energy Transfer Rate, Radial Distribution and Effective Excitation
Authors: Liu Wen , Zhao Jinsong , Xie Huasheng , Wu Dejin
Published: March 2021

Differential flow among different ion species are always observed in the solar wind, and such ion differential flow can provide a free energy to drive the Alfven/ion-cyclotron and fast-magnetosonic/whistler instabilities. Previous works on the ion beam instability are mainly focused on the solar wind parameters at 1 au. We extend this study using the radial model of the magnetic field and plasma parameters in the inner heliosphere. We present the distributions of the energy transfer rate among the unstable waves and the particles, which would be useful to predict the change of parallel and perpendicular temperatures during the instability evolution. Moreover, we propose an effective growth length to estimate the effective growth in each instability, and we explore that the oblique Alfven/ion-cyclotron instability, the oblique fast-magnetosonic/whistler instability and the oblique Alfven/ion-beam instability can be effectively driven by proton beams having speed of 500-2000 km/s in the solar atmosphere. We also show that the unstable waves driven by the proton beam instability would be responsible for the solar corona heating. These predictions can be checked by in situ satellite measurements in the inner heliosphere.
Laboratory and field measurements of HONO emissions from agricultural soils in Guangdong of China 
Authors: Han Baobin , Cheng Peng , Yu Yihang , Yang Wenda , Tian Zhilin , Li Huirong , Gong Yucheng , Chen Bingna , Tian Yujie
Published: March 2021

Laboratory studies indicated that soil could produce considerable nitrous acid (HONO) emissions, which is the main primary source of hydroxyl radical (OH) in the troposphere. However, very few field observations of HONO emission from soil were reported. In order to relate laboratory results and field measurements, we measured HONO emissions from 7 representative agricultural soils (rice, vegetables, orchards, peanuts, potatoes, sugarcane and maize) in Guangdong under controlled laboratory conditions, and took flux measurements on 2 of them (rice and vegetables) by dynamic chambers in the field. Generally, release rates of HONO from the seven soils increased with temperature and varied with soil moisture, and the optimum release rates can be reached under specific values of water-filled pore space (WFPS), which is considered to be beneficial to nitrification. The seven soils' optimum release rates ranged from 1.24 to 43.19 ng kg-1 s-1, and the Q10 (It is defined as the multiple of the increase of soil gas emission rate when the temperature increases by 10℃) ranged from 1.03 to 2.25. Formulas were deduced from the lab results to express HONO emissions for every soil. Flux measurements on two soils varied around -1 to 4 ng N m-2 s-1, and both showed similar diurnal variations with peaks around noontime and very low even negative values during nighttime. There were good correlations between HONO fluxes and soil temperature (R2=0.5). Furthermore, irrigation enhanced the HONO emission substantially. However, a large discrepancy existed between soil HONO emissions measured in lab and low HONO fluxes in field. More investigations are needed to explain the paradox.
Temporal evolution of 3He/4He isotopic ratio at Dos Aguas cold mineral spring, La Palma, Canary Islands
Authors: Padrón Eleazar , Pérez Nemesio M. , Melián Gladys V. , Sumino Hirochika , Alonso Mar , Recio Guillermo , Asensio-Ramos María , Rodríguez Fátima , D’Auria Luca
Published: March 2021

Recent volcanic activity of La Palma island, the fifth in extension (706 km2) and the second in elevation (2,423 m a.s.l.) of the Canarian archipelago, has taken place exclusively in the last 123 ka at the southern part of the island, where Cumbre Vieja volcano, the most active basaltic volcano in the Canaries, has been constructed. A total of seven volcanic eruptions have been reported along the main north-south rift zone of Cumbre Vieja in the last 500 years. On October 7th and 13rd, 2017, two remarkable seismic swarms interrupted a seismic silence of 46 years in Cumbre Vieja volcano with earthquakes located beneath Cumbre Vieja volcano at depths ranging between 14 and 28 km with a maximum magnitude of 2.7. Five more seismic swarms were registered in 2020.

3He/4He ratio has been monitored at Dos Aguas cold mineral spring in La Palma Island since 1991 to date as an important volcano monitoring tool able to provide early warning signal of future volcanic unrest episodes. Magmatic helium emission studies have demonstrated to be sensitive and excellent precursors of magmatic processes occurring at depth. The highest 3He/4He ratio reported to date from the Canarian archipelago has been measured at Dos Aguas: 10.24 RA (being RA the ratio in atmospheric helium) (Padrón et al., 2015). This value is higher than any value found either in the lavas or terrestrial fluid in the Canary Islands, and indicates an important mantle contribution.  According to the temporal evolution of the magmatic component of helium at Dos Aguas, we suggest the occurrence of aseismic magma rising episodes beneath La Palma within the upper mantle towards an ephemeral magma reservoir in the period 2007-2017. However, in the period 2017-2020, magma rising have produced seismic swarms that were accompanied also by the highest 3He/4He ratio measured at Dos Aguas (10.42 RA); both geochemical and geophysical signals confirm an upward magma migration towards a subcrustal magma reservoir beneath La Palma island.

 

Padrón et al., (2015). Bull Volcanol 77:28. DOI 10.1007/s00445-015-0914-2
Participation of pupils in atmospheric measurements -- Potential for increasing climate change risk awareness and data availability for weather and climate research
Authors: Rust Henning , Wentzel Bianca , Kox Thomas , Lehmke Jonas , Böttcher Christopher , Trojand Andreas , Freundl Elisabeth , Göber Martin
Published: March 2021

Voluntarily measuring atmospheric characteristics by citizens has a long tradition. Possibilities has been increasing in the last years with the rise of smart devices and the internet-of-things (IoT). Atmospheric measurements are also prototypical project examples within the Maker community. Maker projects (i.e. IoT-/technology-oriented projects) are popular means of strengthening interest in STEM subjects among pupils. In the frame of two projects, we use an IoT-based weather station to be assembled by pupils as a participatory vehicle to a) raise interest in and understanding of weather and climate, as well as weather forecasts, and b) obtain additional data to be used in scientific projects.  

In the project KARE-CS  (funding: German Ministry for Education and Research, BMBF), a lay weather network has been set up together with pupils in the Bavarian Oberland south of Munich in 2020 and 2021. The students' devices measure temperature, pressure, humidity, solar radiation and precipitation in their direct environment, data is visualized on their smartphones (or any device running a browser) and updated every few minutes. Pupils also report weather impacts such as observed damages or their own concernment about weather events. These data are evaluated in workshops involving the students, their teachers, local partners and scientists. Atmospheric as well as impact data is evaluated for further use in scientifc studies, such as within the mother project KARE (). KARE-CS focuses on upper secondary school students as participants and aim at a development of competences among teachers as multipliers and pupils, particularly in terms of climate change adaptation, understanding natural hazards and risks and in taking personal precautions.

A similar setup is used for supporting the measurement campaing FESSTVaL ( initiated for 2021 by the Hans-Ertel-Centre for Weather Research ( ). The pupils' network will consist of 100 instruments within and close to the campaign's main site. Additionally to the communication and education-oriented goals mentioned above, the resulting spatially and temporally high-resolution data is used for research on thunderstorm development and cold pool characteristics within the Hans-Ertel-Centre.
Lightning to wind-turbines during snowstorm Filomena over Catalonia
Authors: Pineda Nicolau , Montanyà Joan , Romero David , van der Velde Oscar A. , Soler Xavier , López Jesús A. , Solà Gloria
Published: March 2021

Winter storm Filomena battered the Iberian Peninsula on the 9-10th January 2021, covering the eastern half of Spain with a huge amount of snow. Apart from the historical snowfall (e.g. Madrid 40-50 cm), lightning has been recorded during this winter episode. Most of the lighting was oversea, associated with the surface low in southern Spain. Still, some scattered lightning was also recorded in other regions of the Iberian Peninsula like Galicia, Asturias, Extremadura, Valencia and Catalonia.

This study focuses on the just over a dozen of stokes that hit southern Catalonia. Interestingly, inland lightning took place on the evening of the 9th January although NWP models showed no convection conditions over land, the sounding was stable and CAPE was found only far away over sea.

A closer look at the lightning spots showed wind turbines in the close vicinity of all CG stokes. To check the veracity of these winter lightning, data has been gathered from two independent Lightning Location Systems.

By means of data from different meteorological systems from the Meteorological Service of Catalonia (weather radar, automatic weather stations), the meteorological conditions during the lightning occurrence are analysed.

Since lightning only occurred on wind turbines, the effect of rotation may be a key factor on the triggering of lightning from wind-turbines, because the rotation might enhance the electric field at the tips of the blades because they are less shielded by the space charge produced by themselves.
Understanding 21Ne inventories in Precambrian basement below the Great Unconformity in Estonia
Authors: Hall Adrian M. , Stuart Fin , Kirsimae Kalle , Somelar Peeter
Published: March 2021

Stable cosmogenic Ne isotopes are widely used to determine the erosion rate of slowly-eroding land surfaces through the Cenozoic. Constraining erosion and surface exposure back in Earth history remains a challenge largely due to the presence of Ne isotopes generated by natural decay processes over the lifetime of rocks.  Prospects are best when cosmogenic nuclide production has been significant and nucleogenic Ne production is low and can be quantified.  We have explored the limits of palaeo-cosmogenic Ne in one of the Earth’s most extensive erosion surfaces, the late Precambrian Great Unconformity in Estonia. Here deep kaolinitic saprolites formed on Baltica prior to the deposition of Late Ediacaran quartz sandstones. On the basis of geochemical mass balance the duration of saprolite development is estimated to be of the order of a few Myr.

Borehole F163 samples a section through still-buried weathered unconformity that includes a saprolite surface consistent with negligible erosion during the marine transgression. Samples from the unconformity have 21Ne concentrations (>108 atoms/g) that are significantly higher than shielded samples from >20 m below the unconformity. This difference is borne out by Ne isotope composition, and leads to the tanatalising prospect that Precambrian cosmogenic Ne is present in the saprolite. Using modern 21Ne production rates the palaeosols appear to record a few million years irradiation. This is broadly consistent with geochemical estimates of saprolite development.  Samples from the uppermost preserved part of the weathering profile in borehole F231 have low 21Ne concentrations that are indistinguishable from deeper in the rock profile. This would require profile truncation or the redeposition of weathered material.  The borehole is located on the western flank of an uplifted basement block rising ca 130 m above the typical Precambrian basement level in the area and likely that the thick regolith contains material eroded from the uplifted basement units. Clearly these are early days and quantifying surface exposure in deep time will require effort in field as well as the lab.
Open AR-Sandbox: a Haptic Interface for Geoscience Education and Outreach
Authors: Wellmann Florian , Virgo Simon , Escallon Daniel , de la Varga Miguel , Jüstel Alexander , Wagner Florian , Kowalski Julia , Fehling Robin
Published: March 2021

Augmented Reality Sandboxes are a valuable tool for science outreach and teaching due to their intuitive and haptic interaction-enhancing operation. Most of the common AR-Sandboxes are limited to the visualization of topography with contour lines and colours, as well as water simulations on the digital terrain surface. However, many geologists will intuitively want to use this system to visualize geology and literally “dig deeper”, to see how geological units change below the surface. In fact, if we consider the AR-Sandbox in its bare essential, as a 2.5-D haptic dynamic interface to a 3-D or 4-D system, then many more potential applications come to mind: from geological education and outreach, over the representation of geophysical fields, to dynamic simulations. 

In this contribution, we present an open-source implementation of an AR-Sandbox system with an interface in Python, which enables simple access to this tool. This implementation allows for creative and novel applications in geosciences education and outreach in general. With a link to a 3-D geomodelling system, we show how we can display geologic subsurface information such as the outcropping lithology, creating an interactive geological map for structural geology classes. The relations of subsurface structures, topography and outcrop, can be explored in a playful and comprehensible way. Additional examples are geoelectric fields and the propagation of seismic waves, as well as simulations of landslides at the surface. We further extended the functionality with an implementation of ArUco marker detection to enable interactive cross-section generation, among other examples. Many other implementations can be envisaged for the use of this system, and we look forward to creative contributions to geoscience education.
Influence of a small and maximum lake and wetland extent on the simulated West African monsoon precipitation during the mid-Holocene
Authors: Specht Nora , Claußen Martin , Kleinen Thomas
Published: March 2021

During the mid-Holocene, an expansion of vegetation, lakes and wetlands over North Africa reinforced the West African monsoon precipitation increase that was initiated by changes in the orbital forcing. Sedimentary records reflect these surface changes, however, they provide only limited spatial and temporal information about the size and distribution of mid-Holocene lakes and wetlands. Previous simulation studies that investigated the influence of mid-Holocene lakes and wetlands on the West African monsoon precipitation, prescribed either a small lake and wetland extent or focusing on mega-lakes only. In contrast to these simulation studies, we investigate the range of simulated West African monsoon precipitation changes caused by a small and a potential maximum lake and wetland extent during the mid-Holocene.

Therefore, four mid-Holocene sensitivity experiments are conducted using the atmosphere model ICON-A and the land model JSBACH4 at 160 km resolution. The simulations have a 30-year evaluation period and only differ in their lake and wetland extent over North Africa: (1) pre-industrial lakes, (2) small lake extent, (3) maximum lake extent and (4) maximum wetland extent. The small lake extent is given by the reconstruction map of Hoelzmann et al. (1998) and the potential maximum lake and wetland extent is given by a model derived map of Tegen et al. (2002).

The simulation results reveal that the maximum lake extent shifts the Sahel precipitation threshold (> 200 mm/year) about 3 ° further northward than the small lake extent. The major precipitation differences between the small and maximum lake extent results from the lakes over the West Sahara. Additionally, the maximum wetland extent causes a stronger West African monsoon precipitation increase than the equally large maximum lake extent, particularly at higher latitudes.
Short and long term probabilistic slope stability analyses of a large area of unsaturated pyroclastic soils
Authors: Tofani Veronica , Cuomo Sabatino , Masi Elena Benedetta , Moscariello Mariagiovanna , Rossi Guglielmo , Matano Fabio
Published: March 2021

The analysis of slope stability over large areas is a demanding task for several reasons, such as the need for extensive datasets, the uncertainty of collected data, the difficulty of accounting for site-specific factors, and the considerable computation time required due to the size of investigated areas, which can pose major barriers, particularly in civil protection contexts where rapid analysis and forecasts are essential. However, as the identification of zones of higher failure probability is very useful for stakeholders and decision-makers, the scientific community has attempted to improve capabilities to provide physically based assessments. This study combined a transient seepage analysis of an unsaturated-saturated condition with an infinite slope stability model and probabilistic analysis through the use of a high-computing capacity parallelized platform. Both short- and long-term analyses were performed for a study area, and roles of evapotranspiration, vegetation interception, and the root increment of soil strength were considered. A model was first calibrated based on hourly rainfall data recorded over a 4-day event (December 14–17, 1999) causing destructive landslides to compare the results of model simulations to actual landslide events. Then, the calibrated model was applied for a long-term simulation where daily rainfall data recorded over a 4-year period (January 1, 2005–December 31, 2008) were considered to study the behavior of the area in response to a long period of rainfall. The calibration shows that the model can correctly identify higher failure probability within the time range of the observed landslides as well as the extents and locations of zones computed as the most prone ones. The long-term analysis allowed for the identification of a number of days when the slope factor of safety was lower than 1.2 over a significant number of cells. In all of these cases, zones approaching slope instability were concentrated in specific sectors and catchments of the study area. In addition, some subbasins were found to be the most recurrently prone to possible slope instability. Interestingly, the application of the adopted methodology provided clear indications of both weekly and seasonal fluctuations of overall slope stability conditions.
Incremental shortening calculation of the mixed-shear fault-bend folds
Authors: Zhang Weiheng , Chen Jie , Li Tao
Published: March 2021

Shear fault-bend folds are characterized by a long back-limb that dips more gently than the fault ramp [1]. During the folding growth, the back limb rotates and widens progressively through a combination of limb rotation and kink-band migration. Two end-member models of shear fault-bend folding theories, including simple-shear fault-bend folding (C=0.5) and pure-shear fault-bend folding (C=1), have been developed and widely applied. Mixtures of pure and simple shear (0.5<C<1) are possible and have been found in the natural. Few quantitative methods to limit the shear-index (C) of the shear fault-bend folds so far. The incremental shortening can be calculated based on a simplified equation that assumes the linear relationship between the shortening and the limb rotation angle of the back limb [2]. However, the relationship of these two parameters is nonlinear according to the shear fault-bend folding theory [1]. Calculation results of the linear model have large uncertainty.

Here, we develop a method to calculate the shear-index (C), providing an idea to improve the mixed-shear fault-bend fold models, and establishing a formula to calculate the incremental shortening based on the nonlinear relationship between the back-limb dip angle and the shortening. It is a more general method to calculate the incremental shortening of the shear fault-bend folds.

This model has been applied to the Tugulu anticline in the northern foreland of Chinese Tian Shan, which is a mixed-shear fault-bend fold based on previous studies [3]. Through an analysis of deformed fluvial terraces and growth strata, we develop the shortening history of the Tugulu anticline along the Hutubi River using our developed nonlinear model. Our results show that the Tugulu anticline has a shear-index of ~0.91 and a steady shortening rate of ~1.5mm/yr over the last 500ka.

References:

[1] Suppe et al. (2004) AAPG Memoir 82: 303-323.

[2] Yue et al. ( 2011) AAPG Memoir 94: 153–186.

[3] Qiu et al. ( 2019) Tectonophysics 772:228209.
Ice-ocean interactions on Ryder Glacier in North Greenland 
Authors: Nilsson Johan , Jakobsson Martin , Stranne Christian , O'Regan Matt , Mayer Larry
Published: March 2021

Here, we report oceanographic observations and multi-beam bathymetry from the previously uncharted Sherard Osborn Fjord in North Greenland, collected in the summer of 2019 by the Swedish icebreaker Oden. Ryder Glacier, which has Greenland's third largest floating ice tongue, discharges into Sherard Osborn Fjord. The observations show that Arctic Atlantic Water interacts with the ice tongue, creating a prominent intermediate layer of glacially-modified water in the fjord. However, a secondary sill in the inner fjord restricts the heat carried by the Atlantic Water towards Ryder Glacier’s floating tongue, thereby reducing basal melt rates. The observations indicate that the inflow of Atlantic Water over the inner sill is limited by hydraulic control, and that shear-driven vertical mixing cools the inflow reaching the ice tongue. The interactions between the flow and the sill geometry suggest a negative feedback, which reduces the sensitivity of the basal melt rate to variations of Atlantic Water temperature. This may help to explain why the extent of Ryders Glacier's ice tongue has remained stable over the past 50 years, whereas the neighbouring Petermann Glacier's ice tongue, with a different sill geometry, has retreated significantly.  
ICNet Global: Infrastructure and Climate Networks of Networks
Authors: Stoner Anne , Jacobs Jennifer , Sias Jo , Airey Gordon , Hayhoe Katharine
Published: March 2021

Climate change is already impacting the performance and integrity of transportation infrastructure around the world and is anticipated to have serious ramifications for infrastructure safety, environmental sustainability, economic vitality, mobility and system reliability. These impacts will disproportionately affect vulnerable populations and urban locations as well as compromising the resilience of the larger interconnected physical, cyber, and social infrastructure networks. For this reason, increasing the resilience of transportation infrastructure to current and future weather and climate extremes is a global priority.

The complexity of this challenge requires a convergence approach to foster collaboration and innovation among technically and socially diverse researchers and practitioners. The multi-institutional ICNet Global Network of Networks unites domestic and international research and practice networks to facilitate integrated engineering, climate science, and policy research to advance the development of resilient transportation infrastructure and systems. ICNet Globalcollaborators represent networks based in Korea, Europe, United Kingdom, and the United States and link researchers at the forefront of scientific, engineering, and policy research frontiers, drawing expertise from many disciplines and nations to share and enhance best practices for transportation resilience.

ICNet Global’s long-term mission is to prepare the world’s existing and future transportation infrastructure for a changing climate. To that end, we are working to: (1) build a network of existing research networks who are tackling the challenges climate change poses to transportation infrastructure; (2) establish a common base-level knowledge, capacity, and vision to support the convergence of novel and diverse ideas, approaches, and technologies for creating climate resilient transportation infrastructure; and (3) grow the next generation of critical and diverse thinkers with the expertise to address and solve climate-related infrastructure challenges. Although just one year into our work, and dispite challenges represented by COVID-19, we have surveyed over 100 potential members worldwide to learn about fields of interest and held five productive virtual workshops to discuss current research, how to encorporate climate change information into engineering education, and how practitioners are currently including climate information into planning and design. In this presentation we highlight our goals and recent accomplishments while laying out future plans and inviting interested researchers and practitioners to join us.
Observations of internal gravity waves in vicinity of jet streams during SouthTRAC flight on 16 September 2019
Authors: Woiwode Wolfgang , Dörnbrack Andreas , Friedl-Vallon Felix , Geldenhuys Markus , Giez Andreas , Gulde Thomas , Höpfner Michael , Johansson Sören , Kaifler Bernd , Kleinert Anne , Krasauskas Lukas , Kretschmer Erik , Maucher Guido , Neubert Tom , Nordmeyer Hans , Piesch Christof , Preusse Peter , Rapp Markus , Riese Martin , Ungermann Jörn
Published: March 2021

The combination of the airborne GLORIA (Gimballed Limb Observer for Radiance Imaging of the Atmosphere) and ALIMA (Airborne LIdar for Middle Atmosphere research) instruments allows for probing of temperature perturbations associated with gravity waves within the range from the troposphere up to the mesosphere. Both instruments were part of the scientific payload of the German HALO (High Altitude and LOng Range Research Aircraft) during the SouthTRAC-GW (Southern hemisphere Transport, Dynamics, and Chemistry - Gravity Waves) mission, aiming at probing gravity waves in the hotspot region around South America and the Antarctic peninsula. For the research flight on 16 September 2019, complex temperature perturbations attributed to internal gravity waves were forecasted well above the Atlantic to the south-west of Buenos Aires, Argentina. The forecasted temperature perturbations were located in a region where the polar front jet stream met with the subtropical jet, with the polar night jet above. We present temperature perturbations observed by GLORIA and ALIMA during the discussed flight and compare the data with ECMWF IFS (European Centre for Medium-Range Weather Forecasts – Integrated Forecasting System) high-resolution deterministic forecasts, aiming at validating the IFS data and identifying sources of the observed wave patterns.
Runoff predictive capability of a simple LSTM model versus a proven conceptual model between diverse hydrological regimes
Authors: Hashemi Reyhaneh , Brigode Pierre , Garambois Pierre-André , Javelle Pierre
Published: March 2021

In the field of deep learning, LSTM lies in the category of recurrent neural network architectures. The distinctive capability of LSTM is learning non-linear long-term dependency structures. This makes LSTM a promising candidate for prediction tasks in non-linear time dependent systems such as prediction of runoff in a catchment. This work presents a comparative framework between an LSTM model and a proven conceptual model, namely GR4J. Performance of the two models is studied with respect to length of study period, surface area, and hydrological regime of 491 gauged French catchments covering a wide range of geographical and hydroclimatic conditions.  

Meteorological forcing data (features) include daily time series of catchment-averaged total precipitation, potential evapotranspiration, and air temperature. The hydrometric data consists of daily time series of discharge (target variable). The length of study period varies within the sample depending on the availability of full-record of discharge and, on average,  is 15 [years].

In equivalent experimental scenarios, features are kept same in both models and the target variable is predicted for each catchment by both models. Their performance is then evaluated and compared. To do this, the available time series are split into three independent subsequent subsets, namely, training set, validation set, and evaluation set, constituting, respectively, 50%, 20%, and 30% of the study period. The  LSTM model is trained based on the training and validation sets and predicts the target on the evaluation set. The four parameters of GR4J model are calibrated using the training set and the calibrated model is then used to estimate discharges corresponding to the evaluation set. 

The results suggest that the hydrological regime of catchment is the main factor behind the performance pattern of the LSTM model. According to the results, in the hydrological regimes Uniform and Nival, involving flow regimes with dominant long-term processes, the LSTM model outperforms GR4J model. However, in Pluvial-Mediterranean and Pluvial-Nival regimes characterised with pluri-season peaks, the LSTM model underperforms GR4J model.
Tree above-ground biomass dynamics in the Northeast Siberian tundra-taiga from nowadays to 3000 AD
Authors: Shevtsova Iuliia , Herzschuh Ulrike , Heim Birgit , Kruse Stefan
Published: March 2021

Changes in future above-ground biomass (AGB) of terrestrial ecosystems is one of the current interests in the light of climate change and essential to forecast for predicting potential climate feedbacks such as influence on the carbon balance. The tundra-taiga ecotone is a region that is prone to notable above-ground biomass changes, in the first instance due to the treeline advance. Forest is expected to occupy non-polygonal tundra. Our study region in central Chukotka (Northeastern Siberia) is a mountainous area on the northern border of the tundra-taiga ecotone that covers a wide range of vegetation types on a density gradient starting with lichen communities via open graminoid tundra to forest tundra. There is only one tree species – a deciduous conifer Larix cajanderi. We applied the individual-based spatially explicit model LAVESI to simulate larch AGB change from nowadays to 3000 AD under different climate scenarios, depending on Representative Concentration Pathways (RCPs) RCP 2.6, RCP 4.5 and RCP 8.5. We implemented in the model topographical parameters, as well as region-specific individual larch AGB equations, biological parameters of the tree growth and climate variables. We validated the new version of the model against field and Landsat satellite-based data, as well as a high spatial resolution image with distinctive trees visible, provided by ESRI (ArcGIS/World_imagery). Our first results are indicating mostly densification of existing tree stands before 2200 AD and forest expansion in the study region after 2200 AD even under the mildest RCP 2.6 scenario. First evaluations of the average tree AGB increase rates from present to 2200 AD are ranges from 0.007 (RCP 2.6) to 0.01 (RCP 8.5) kg*m-2*yr-1. Obtained rates of tree AGB change and its future distribution on the landscape can be particularly useful for conservation measures and modelling of future above-ground carbon stock dynamics.
Impact of initialization techniques on the predictive skill of Arctic-Atlantic region in the Norwegian Climate Prediction Model (NorCPM)
Authors: Passos Leilane , R. Langehaug Helene , Årthun Marius , Eldevik Tor , Bethke Ingo , Kimmriz Madlen
Published: March 2021

Society's need for operational climate forecast on seasonal to decadal time scales means an increased effort to improve climate prediction models. One way to address this issue is to investigate how initialization techniques affect the predictive skill in these systems.

Considering this, three implementations and two versions of the Norwegian Climate Prediction Model (NorCPM) are analyzed concerning the effects of different initialization methods on the predictive skill in the Arctic-Atlantic region from interannual to decadal time scales. We consider aspects as data assimilation (DA) in the surface vs subsurface, DA update of sea-ice, CMIP5 vs CMIP6 NorCPM versions, ensemble size, and initialization frequency. Besides that, a comparison between the predictive skill in the Norwegian Sea (NS) and the Subpolar North Atlantic Ocean (SPNA) is performed to identify characteristics that can help to improve predictions in these areas.

The additional assimilation of subsurface data increases the predictive skill in the SPNA at all lead times (1-10 years). In contrast, in the NS the skill is increased just at medium lead times (4-7 years). The strongly coupled DA, updating both ocean and sea ice, increases the predictive skill in the SPNA at all lead times, whereas the weakly coupled DA method, only updating ocean, results in higher skill in the NS at shorter (1-3 years) and medium (4-7 years) lead times. With respect to the NorCPM versions, the CMIP5 versions show higher predictive skill in both areas than the CMIP6 ones. In this comparison, besides the differences in the climate forcings, the new NorCPM version contributing to CMIP6 has minor code modifications, addition of interactive aerosol-cloud schemes, and an ocean component with biogeochemistry. Because of that, it is not possible to isolate just the effect of the climate forcings on the skill. Regarding the ensemble size and initialization frequency, NorCPM had a non-linear response; the skill varies with the area, variable, and lead times.

Considering the results, no single version was superior to the others with respect to the skill. In the SPNA, the CMIP5 version, assimilating both surface and subsurface observations, and using strongly coupled DA, shows the highest skill. In the NS, we find the similar except that the highest skill is shown for the weakly coupled DA. Further investigation about technical aspects and the representation of dynamical process are necessary to better understand why the sea ice updating in the strongly coupled method is not beneficial to the NS.
Inter-comparison of GNSS-Reflectometry measurements from CYGNSS and Spire’s satellites with SMAP soil moisture product
Authors: Freeman Vahid , Jales Philip , Esterhuizen Stephan , Irisov Vladimir , Cartwright Jessica , Masters Dallas
Published: March 2021

The potential of space-borne GNSS-Reflectometry (GNSS-R) technique for soil moisture retrieval has been demonstrated in recent studies using observations from the NASA’s Cyclone Global Navigation Satellite System (CYGNSS) and the UK’s Technology Demonstration Satellite, TechDemoSat (TDS-1).

Spire Global operates a constellation of CubeSats performing GNSS based science and Earth observation. In December 2019, Spire launched two new satellites with GNSS-R payloads with plans to launch two more follow-on GNSS-R missions in January 2021. In this study, we highlight the capabilities of the Spire’s current and future GNSS-R missions compared to CYGNSS for global soil moisture monitoring and present the results of an inter-comparison between CYGNSS and Spire GNSS-R observables over land with NASA’s Soil Moisture Active Passive (SMAP) observations. The comparison of level-1 data and various statistical parameters was performed after data collocation both trackwise and also within a 6km regular grid. The results of the study were used for intercalibration of CYGNSS and Spire’s GNSS-R measurements for developing a combined GNSS-R soil moisture product.
A Bayesian data assimilation approach to estimating land-use change
Authors: Levy Peter E.
Published: March 2021

The aim of this work was to make improved estimates of land-use change in the UK, using multiple sources of data. We applied a method for estimating land-use change using a Bayesian data assimilation approach. This allows us to constrain estimates of gross land-use change with national-scale census data, whilst retaining the detailed information available from several other sources. We produced a time series of maps describing our best estimate of land-use change given the available data, as well as the full posterior distribution of this space-time data cube. This quantifies the joint probability distribution of the parameters, and properly propagates the uncertainty from input data to final output. The output data has been summarised in the form of land-use vectors. The results show that we can provide improved estimates of past land-use change using this method. The main advantage of the approach is that it provides a coherent, generalised framework for combining multiple disparate sources of data, and adding further sources of data in future is straightforward.
Dependence Types in a Binarized Precipitation Network
Authors: Meroni Viola , De Michele Carlo , Rahimi Leila , Deidda Cristina , Ghezzi Antonio
Published: March 2021

In a network of binarized precipitation (i.e., wet or dry value), the connection or dependence between each pair of nodes can occur following one or more of the following conditions: wet‐wet, dry‐dry, wet‐dry, or dry‐wet. Here, we firstly investigate the different types of dependence, year by year, within a precipitation network of binarized variables. We compare the sample estimate of the probability of co‐occurrence (or occurrence with a lag time within ±3 days) of each of the four possible combinations with respect to the correspondent confidence interval in hypothesis of independence. We develop a procedure to efficiently assess the dependence behavior of all couples of nodes within the network and apply the methodology to a network of rain gauges covering Europe and north Africa.
Moraine destabilization leading to the 2013 landslide onto Svínafellsjökull glacier, SE Iceland
Authors: Ben-Yehoshua Daniel , Sæmundsson Þorsteinn , Helgason Jón Kristinn , M.C. Belart Joaquin , Erlingsson Sigurður
Published: March 2021

On February 27th 2013 a large landslide fell onto Svínafellsjökull glacier, on the western slope of Öræfajökull volcano, SE Iceland. The slide occurred during an intensive rainstorm event between February 24th and 27th. The slide was detected at 20:30 o’clock at a seismic station located several kilometres away. It originated from lateral moraine and talus material below the steep north-eastern slope of Mt. Skarðatindur above a small contributory glacier. The debris flowed down-glacier towards the west with an approximate runout distance of 3000 m and a width of 500-600 m, covering about 1,4 km2 or about 17% of the glaciers’ surface. The extent of the debris deposit suggests a highly water saturated debris flow. Based on Digital Elevation Models (DEMs) from 2011 and 2013 the estimated volume of the slide was 5,4±0,1 million m3 which makes it one of the largest debris slides in Iceland over the last decades.
Long term destabilization by glacier unloading was investigated by comparing DEMs from 1994 to 2011. Meteorological data suggests that record breaking amounts of precipitation in combination with snowmelt due to relatively warm temperatures in late February caused a significant water inflow into the system which is likely to have caused the failure.
Analysis of aerial imagery and DEMs after the failure suggest a complex slide. The debris cover on the glacier reduced the surface ablation which resulted in an up to 30 m height difference between the debris free glacier surface and the debris covered part in 2020.
Surface deformations observed by GPS and its relation to groundwater variations in France
Authors: Saraswati Anita Thea , Hsu Kuei-Hua , van Dam Tonie , Eicker Annette
Published: March 2021

The Global Positioning System (GPS) measures surface displacements in response to time-varying terrestrial water mass variations. Components of surface water storage include water in lakes and reservoirs, snow, and soil moisture. Groundwater depletion or recharge will also contribute to the overall water storage. Understanding the nature of the observed GPS displacements related to the continental water variations is important to help identify which compartment in the total water storage controls the water changes in any particular region. In this study, we demonstrate the potential of GPS to observe the surface displacements induced by groundwater variations in France. In-situ groundwater observations from boreholes in France are used to be compared with GPS displacements. Groundwater data are processed to obtain the Equivalent Water Height (EWH) and used to forward model surface deformation. Displacements predicted using EWH variations from the WaterGAP Global Hydrology Model (WGHM) will also be compared to the GPS displacements.