bluuebunny/crossref_metadata_2025 huggingface dataset:
Tilt removal on 6-axis ground motion measurements: experiments at iXblue
Authors: Lenogue Guillaume , Pinot Baptiste , Guattari Frederic , Mimoun David
Published: March 2022

The recent development of rotational sensors of increased sensitivity and portability allowed for co-located 6-axis seismological measurements. This opens new possibilities for the study of seismic records. For example, back-azimuth can be computed with a single station horizontal axis rotations. One of the most promising developments is the ability to remove the projection of the gravitational acceleration on the horizontal translation directions in case of tilting of the sensor assembly, which was formerly indistinguishable from a true acceleration.

A 6-C experiment was conducted at a testing facility at iXblue Saint-Germain-en-Laye, France. Different data processing algorithms for tilt removal, as well as a new algorithm developed for this study (whose mathematical basis will be detailed in another submitted abstract) have been applied to this experiment and their results were compared. Contrary to field measurements, tests in laboratory allowed to test edge cases of the different methods.
 Stratospheric Aerosol and Gas Experiment III on the International Space Station(SAGE III/ISS): Continuing the Legacy of SAGE Data Products
Authors: Kizer Susan , Roell Marilee , Flittner David , Damadeo Robert , Leavor Kevin , Roller Carrie , Hurst Dale , Hall Emrys , Jordan Allen , Cullis Patrick , Johnson Bryan , Querel Richard
Published: March 2022

The Stratospheric Aerosol and Gas Experiment III (SAGE III) instrument installed on the International Space Station (ISS) has completed almost half of a decade of data collection and production of science data products. The SAGE III/ISS is a solar and lunar occultation instrument that scans the light from the Sun and Moon through the limb of the Earth’s atmosphere to produce vertical profiles of aerosol, ozone, water vapor, and other trace gases. It continues the legacy of previous SAGE instruments dating back to the 1970s to provide data continuity of stratospheric constituents critical for assessing trends in the ozone layer. This presentation shows how SAGE III/ISS aerosol and gas vertical profiles continue to benefit a worldwide database of in situ and satellite data for climate observation.
Paleoenvironmental implications of grain size characteristics of loess key-sites from opposite banks of the Middle Dnieper River valley (Ukraine)
Authors: Mroczek Przemysław , Łanczont Maria , Komar Maryna , Nawrocki Jerzy , Standzikowski Karol , Hołub Beata , Krokhmal Oleksyi , Derevska Kateryna
Published: March 2022

The loesses of central Ukraine, occurring on both sides of the submeridional-oriented Dnieper River valley, have the character of continuous patches up to 30 or even 50 meters thick. In geological exposures (mainly cliffs) they have the character of loess-palaeosol sequences, additionally separated by glacial till (Saalian), which plays an important role as a stratigraphic marker. The loess cover underlies the river sediments of the Pleistocene Dnieper terraces. A characteristic feature of the documented sequences is a clear difference in their thickness, as well as litho- and pedological formation on opposite banks of the Dnieper River.

Grain size analyses (laser and sieve) of a number of sequences on both sides of the river were conducted. The assumed constant interval was 5 cm. Based on the measurements, accurate statistical characterization of the individual fractions and subfractions was developed and a number of indices were calculated that may be of great value in environmental interpretations.

Paleogeographic conclusions from sedimentological studies were focused on the characterization of depositional environments. The basic conclusion is the documented great dissimilarity of grain size characteristics of lithological units of the same age on both sides of the Dnieper valley. This reflects the different nature and high variability of environmental conditions during accumulation period. The study clearly shows that the valley was an important source of windblown silty material, but also its morphologically diverse banks were important orographic barriers for aeolian transported material. Moreover, a strong connection between the investigated aeolian sediments and the older, underlying layers of different origin – glacial and fluvial – was demonstrated.

Research carried out as part of the grant of National Science Centre, Poland as the project no. 2018/31/B/ST10/01507 entitled “Global, regional and local factors determining the palaeoclimatic and palaeoenvironmental record in the Ukrainian loess-soil sequences along the Dnieper River Valley – from the proximal areas to the distal periglacial zone”.
Comparing miscanthus hybrids – growth and environmental impacts
Authors: Shepherd Anita , Awty-Carroll Danny , Kam Jason , Ashman Chris , Magenau Elena , Martani Enrico , Kontek Mislav , Ferrarini Andrea , Amaducci Stefano , Davey Chris , Al Hassan Mohamad , Jurišić Vanja , Lamy Isabelle , Lewandowski Iris , de Maupeou Emmanuel , McCalmont Jon , Trindade Luisa , Kiesel Andreas , Clifton-Brown John , Hastings Astley ,   Anita Shepherd1
Published: March 2022

Our research is aligned to the expansion of energy crops with a view to future developments in greenhouse gas removal and we need to ensure that does not have a detrimental effect on the surrounding environment.

Miscanthus is a sustainable bioenergy crop which is wildlife-friendly and will grow on otherwise unproductive land. Mature crops do not require fertilizer thereby ensuring low nitrous oxide emissions. Miscanthus x giganteus (M x g) as a sterile clone, has been propagated vegetatively, with relatively high establishment costs and low multiplication rates. New seed-propagated hybrids, with the potential of upscaling the crop for greater provision, are being readied for market and in crop trials over Europe.

Projections are presented from research involving the international GRACE project and the Supergen SUMMER project. We determine the potential for miscanthus growth and environmental impact, using the hybrids under 21st century climate conditions. We show yield projections which have been modelled using crop trial data across different European countries together with simulations from the MiscanFor model for agricultural soil carbon sequestration and water deficit.
Nitrogen cycling in forest soils under elevated CO2: response of a key soil nutrient to climate change
Authors: Rumeau Manon , Ullah Sami , Mackenzie Rob , Carillo Yolima , Reay Michaela , Sgouridis Fotis
Published: March 2022

Forests under elevated atmospheric CO2 concentration as a result of climate change are expected to require more available nitrogen (N) to sustain the enhanced CO2 uptake for photosynthesis and C storage. Therefore, it is essential to evaluate how CO2 fumigation of forests will affect availability of N to trees. Main pathways to sustain the high N demand are increasing biological N fixation (BNF), increasing N turn-over and reducing N losses. The purpose of this research is to explore the effects of elevated CO2 on soil N cycling in a temperate forest under the Birmingham Institute of Forest Research (BIFoR) Free Air Carbon Dioxide Enrichment facility. We hypothesize that under CO2 fertilization, trees will allocate more carbon belowground to enhance microbial activity for increasing N mineralization as well as enhancing BNF to meet N demands. We also hypothesize that the subsequent microbial activity will up-regulate N2O and N2 emissions due to denitrification. BNF by free-living organisms is investigated using the 15N assimilation method. Mineralization and N gas production rates is determined using the 15N pool dilution and 15N-Gas flux method at the same time. Early results are showing trends toward an enhancement of N mineralization and microbial N immobilization rates. However, BNF in the forest floor is hardly detectable more likely because of the high N deposition in the area; therefore, it doesn’t appear to be responsive to CO2 fumigation. This research is expected to help us improve our understanding of the changes and magnitude of nutrient availability and gaseous losses under future climates.
Recent Observations of the Bottom Mixed Layer in the Tropical Northeast Pacific Ocean
Authors: Chen Si-Yuan Sean , Muños Royo Carlos , Ouillon Raphael , Alford Matthew , Peacock Thomas
Published: March 2022

The bottom mixed layer (BML) is a well mixed, weakly stratified bottom boundary layer adjacent to the seafloor, with a thickness of the order 10-100 m, and is considered a common feature of the deep water column in the ocean. First observed in the 1970s and documented extensively in the deep Northwest Atlantic Ocean in the 1980s, the abyssal ocean (depth > 4000 m) BMLs have not been well observed in other regions of the global oceans, particularly in the Northeast Pacific Ocean, and the dynamical processes that lead to their formation are not well understood. Turbulent diffusivity in the BML is estimated to be greater than in the interior ocean by an order of magnitude, and the presence of such layers is often associated with elevated level of turbidity and episodic events of sediment resuspension and transport, known as the benthic storms. Without a clear understanding of the variability and dynamics of these layers, assessing potential environmental impacts of proposed commercial activities in the deep sea, such as the exploitation of polymetallic nodules in the Clarion-Clipperton Fracture Zone (CCFZ) in the tropical Northeast Pacific, is challenging. 

 

In this study, we analyze observed profiles from conductivity-temperature-depth (CTD) measurements recently collected in the German licence area of the CCFZ, a region with abyssal hills west of the East Pacific Ridge. Quasi-uniform profiles of potential temperature, salinity, and potential density extending from the seafloor to a maximum of 475 m above bottom (mab) reveal the presence of a BML in the region with a thickness of O(100 m), using a mixed-layer quantification method based on potential temperature profiles. The BML thickness and structure vary both temporally and spatially, with three major characteristics: (i) a well-developed, statically stable BML with a thickness between 200 and 475 m; (ii) a less well-developed BML with a thickness of approximately 100 m; and (iii) a well developed BML with a thickness of around 400 m and multiple intrusive layering structures, each of which with a thickness of approximately 100 m, near bathymetric reliefs. These findings confirm the preliminary findings from the 1980s that benthic stratification in the region is weak and that a mixed layer may be present at the bottom. While our preliminary findings establish the presence of BML in the region, questions regarding the dynamical processes responsible for the temporal and spatial variabilities remain to be addressed. Further analyses using data from the eastern segment of the World Ocean Circulation Experiment (WOCE) tropical North Pacific (P04E) section are ongoing to understand the spatial variability of these layers in the region. 
Geomorphic connectivity analysis for prioritising floodplain wetlands for restoration and monitoring in the Ramganga basin, India 
Authors: Singh Manudeo , Sinha Rajiv
Published: March 2022

Floodplain wetlands are an important and integrated component of riverine environment as they perform various ecological and hydrological functions. However, these wetlands are under acute pressure because of changing climate and land-use and require urgent attention. Stakeholders (e.g., wetland management authorities) need a science-based information about wetlands at basin scale for prioritising them for restoration and monitoring. To facilitate the prioritisation of wetlands, we used geomorphic connectivity concept and hypothesise that the best possible connectivity scenario for the existence of a wetland is (a) if that wetland has a high connectivity with its upslope area, and (b) if that wetland has a low connectivity with its downslope region. The first condition ensures flow of water into the wetland and second condition allows longer residence time of water in the wetland. Accordingly, we defined 4 categories of connectivity-based restoration scenarios – good, no impact, bad, worst. We applied the proposed method to 3226 wetlands of Ramganga Basin in north India which were mapped in our previous work (Singh and Sinha, 2022, Remote Sensing Letters, 13:1, 1-13). The results show that 676 wetlands are in good category, 1155 show no impact, 831 are in bad category, and 564 in worst category. Further selection criteria such as distance from nearest stream and stream density can be applied to filter the wetlands from different connectivity scenario categories. For example, in present case, there are 112 wetlands within 100 m of any stream and require restoration. Therefore, using connectivity concept, it is possible to identify the wetlands which are easiest to restore and to identify those which are under threat. The proposed method can be applied to any basin for wetland management applications.
Greenhouse gas exchange in temperate forest ecosystems in the UK - A quest for key components and drivers
Authors: Toet Sylvia , Ma Ruochan , Barrop Will , Keane Ben , Stockdale James , Andersen Roxane , Anderson Russell , McNamara Niall , Xenakis Georgios , Yamulki Sirwan , Morison James
Published: March 2022

Forests are often considered to be able to play a significant role in tackling global warming. To fully understand their potential in mitigating climate change and to develop more accurate ecosystem GHG flux budgets and process-based models of forests, we require more knowledge of methane (CH4) and nitrous oxide (N2O) exchange in forests, their underlying processes, environmental controls and responses to forest management. In recent years, it is becoming evident that not only soils but also the trees themselves may significantly contribute to CH4 and N2O fluxes in forest ecosystems.

Our research mainly focussed on greenhouse gas (GHG) exchange in temperate UK forests on both mineral and organic soils. We will primarily concentrate on CH4 fluxes as N2O fluxes were often relatively low in these forests and, by including CO2 fluxes, we will put them into the context of the overall ecosystem GHG exchange. A range of flux methods at different scales were used in our field studies to be able to capture the often high temporal and spatial variability of the GHG exchange between the atmosphere and either soils, tree stems or entire trees aboveground, and to identify potential drivers of the fluxes. The impact of management practices including clear fell, drainage and the resulting micro-topography, and forest-to-bog restoration on CH4 fluxes from organic soils following the first forest rotation will also be described. We regularly used novel automated and chamber approaches and technologies, and the advantages and limitations of the different flux approaches and their use to upscale fluxes to the landscape scale will be evaluated.
Defining regime specific cloud sensitivities using the learnings from machine learning
Authors: Douglas Alyson , Stier Philip
Published: March 2022

Clouds remain a core uncertainty in quantifying Earth’s climate sensitivity due to their complex dynamical and microphysical  interactions with multiple components of the Earth system. Therefore it is pivotal to observationally constrain possible cloud changes in a changing climate in order to evaluate our current generation of Earth system models by a set of physically realistic sensitivities. We developed a novel observational regime framework from over 15 years of MODIS satellite observations, from which we have derived a set of regimes of cloud controlling factors. These regimes were established using the relationship strength, as measured by using the weights of a trained, simple machine learning model. We apply these as observational constraints on the ​​r1i1p1f1 and r1i1p1f3 historical runs from various CMIP6 models to test if CMIP6 climate models can accurately represent key cloud controlling factors.. Within our regime framework, we can compare the observed environmental drivers and sensitivities of each regime against the parameterization-driven, modeled outcomes. We find that, for almost every regime, CMIP6 models do not properly represent the global distribution of occurrence, raising into question how much we can trust our range of climate sensitivities when specific cloud controlling factors are so badly represented by these models. This is especially pertinent in southern ocean and marine stratocumulus regimes, as the changes in these clouds’ optical depths and cloud amount have increased the ECS from CMIP5 to CMIP6. Our results suggest that these uncertainties in CMIP6 cloud parameterizations propagate into derived cloud feedbacks and ultimately climate sensitivity, which is evident from a regimed based analysis of cloud controlling factors.
Conductive-radiative boundary conditions and the fractional energy balance equation: predictions and projections
Authors: Lovejoy Shaun
Published: March 2022

The highly successful Budyko-Sellers energy balance models are based on the classical continuum mechanics heat equation in two spatial dimensions. When extended to the third dimension using the correct conductive-radiative surface boundary conditions, the surface temperature anomalies obey the (nonclassical) Half-order energy balance equation (HEBE, with exponent h = ½) implying heat is stored in the subsurface with long memory.  In comparison, the classical EBE has h=1 and short (exponential) system memory.  Using short and long wave data from reanalyses, we discuss the empirical foundations of the FEBE.

Empirically, we find that both internal variability and the forced response to external variability are compatible with h ≈ 0.4.  Although already close to the HEBE and classical continuum mechanics, we argue that an even more realistic “effective media” macroweather model is a generalization: the fractional heat equation (FHE) for long-time (e.g. monthly scale anomalies).  This model retains standard diffusive and advective heat transport but generalize the (temporal) storage term.  A consequence of the FHE is that the surface temperature obeys the Fractional EBE (FEBE).  We show how the resulting FEBE can be been used for monthly and seasonal forecasts as well as for multidecadal climate projections. 
Sedimentologika: a community-driven DOA journal
Authors: Marchegiano Marta , Chiarella Domenico , Jarochowska Emilia , Kane Ian , Mitten Andrew , Privat Aurélia , Poyatos-Moré Miquel , Soutter Euan , Spychala Yvonne , Thomas Camille , Vaucher Romain , Zuchuat Valentin
Published: March 2022

Sedimentologika is a community-driven Diamond Open Access (DOA) scientific journal about sedimentology. The journal aims to create a place where people can publish their research and access scientific studies on all types of sedimentary processes, methods, deposits, and environments, across all spatial and temporal scales, on Earth or any other planetary body, for free. The published material will be free to share (i.e., no embargo period) since authors retain the copyright. Sedimentologika is driven by the community for the community and is part of a broader DOA movement in geosciences. Sedimentologika aspires at emancipating from the financial barriers associated to private publishing houses to provide direct and equal access to science to all citizens, scientists, and institutions all over the globe. This journal will be defined by Open Science principles to promote ethical dissemination of science and knowledge, following high equality, diversity, and inclusion standards. Each step of the review and publication process will be visible and easy to follow for authors, reviewers and the community. Sedimentologika will be launched by mid-2022 and we are always looking for motivated people keen on giving a little bit of their time to make Sedimentologika a viable and recognized peer-reviewed scientific journal. Interested in this initiative? Come discuss with us!
New Tricks for Old Tephra
Authors: Helmick Meredith , Kurbatov Andrei , Yates Martin , Dunbar Nelia , Iverson Nels , Winski Dominic
Published: March 2022

Ice cores serve as archives of the Earth’s past atmosphere and are invaluable to improving our understanding of past climate. These cores preserve regional and global volcanic histories. Traditionally, the chemical components associated with volcanic aerosols measured in ice have been used to identify volcanic deposits in ice. However, only a handful of studies have identified sources of low concentration ultra-fine volcanic ash (cryptotephra) layers associated with chemically identified horizons. A pioneering study by Palais et al., [Annals of Glaciology, 14, 216-220 (1990)], identified five cryptotephra intervals in the PS1 firn core from South Pole, Antarctica. Now, some 30 years later and armed with improved technology, refined methodologies, and the recently drilled South Pole Ice Core (SPC14), we revisit these tephra-bearing volcanic intervals. Guided by high-resolution glaciochemical time series data, we were able to extract  cryptotephra particles from ice intervals corresponding to the eruptions of Tambora (1815 CE); the unknown 1809 CE event; Huaynaputina (1600 CE); Nevado Del Ruiz (1595 CE); and Samalas (1257 CE) at much finer sampling resolutions than was previously possible. Each sample was prepared using recently developed sample mounting techniques tuned to maximize particle recovery, and analyzed using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Both the Tambora and 1809 intervals comprise small (< 2μm) particles ranging in composition from trachyandesitic to rhyolitic. As a whole, cryptotephra particles from the Huaynaputina interval represent largely homogenous rhyolitic particles with minor occurrences of trachyte. The composition of cryptotephra from the Nevado Del Ruiz interval ranges from basaltic trachyandesite to trachyte. Lastly, cryptotephra compositions of the Samalas interval include both rhyodacitic and trachytic particles. We captured a wider range of cryptotephra compositions than previously presented for the selected volcanic intervals and many contain subtropical particles (dacite-rhyolite) and local particles (trachytes). These findings will be informative for understanding volcanic eruption dynamics and atmospheric transport of local and distal tephra. This material is based upon work supported by the USA National Science Foundation under Grants No. PLR-1543454 and 1543361.
Raising awareness of the impact of climate change on coastal regions. A citizen science-based approach within the SECOSTA project
Authors: Herrada E. Alejandro , Puigdefabregas Joan , Agulles Miguel , Ramos Jorge , Frank Aida , Villalonga Joan , Gomis Damià , Jordà Gabriel
Published: March 2022

Coastal regions will be highly impacted by climate change due to the rise of sea level and the impacts of warmer sea temperatures on coastal ecosystems. Moreover, for those regions whose economy is highly dependent on coastal activities, such as maritime transport or coastal tourism, the assessment of coastal vulnerability to climate change is crucial to guarantee their economic resilience. Since 2018, the SECOSTA project (https://secosta.wordpress.com/) has launched different citizen science-based programs (SOCLIMPACT, VENOM, DECIMATE) focused on monitoring the impact of climate change on coastal areas. The goal is twofold. On the one side, the SECOSTA project aims to make high school students aware of climate change and of the work developed by scientists. On the other hand, the students contribute to the acquisition of data that will be used in scientific studies afterwards. The SECOSTA project strategy is the following. First, different low cost and open source devices are designed to measure with a reasonable degree of accuracy several parameters (e.g. sea level, atmospheric pressure, beach topobathymetry, sea temperature). Second, high school teachers are trained in dedicated workshops to build those devices with their students. Third, the teachers develop educational multidisciplinary projects in their schools around a particular topic of interest (e.g. sea level rise, ocean warming...) involving the data acquisition. This phase is guided by the scientists who also provide educational resources to help in the development of the educational projects. Finally, the observations obtained by the students are processed by the scientists and incorporated in several research projects as additional datasets.

The project has been successfully implemented creating a robust synergy among researchers, the regional government and secondary schools. To date, close to 20 different secondary schools have taken part in the different initiatives, involving more than 2,000 students per year in the construction of devices, acquisition and processing of data. In light of the success of previous terms, in 2022, the SECOSTA project is going to hold a conference that will serve as a forum for the participating high schools to present the results of their scientific studies. In this presentation we will describe the different steps of the project along with some recommendations about the lessons learned during these years for a successful deployment of citizen-science based projects in secondary schools.
Direct comparison of sporadic E from COSMIC-2 radio occultation and vertical wind shears from ICON/MIGHTI
Authors: Yamazaki Yosuke , Arras Christina , Andoh Satoshi , Miyoshi Yasunobu , Shinagawa Hiroyuki , Harding Brian J. , Englert Christoph R. , Immel Thomas J. , Sobhkhiz-Miandehi Sahar , Stolle Claudia
Published: March 2022

The formation of a sporadic-E (Es) layer at mid and low latitudes is generally attributed to the vertical wind shear, which is predicted to cause vertical ion convergence. According to wind shear theory, a negative shear of the eastward wind is effective in converging metallic ions into a thin layer to produce Es. However, the direct comparison of Es with the local wind shear has been limited due to the lack of neutral wind measurements. This study examines the role of the vertical wind shear for Es, using signal-to-noise ratio profiles from COSMIC-2 radio occultation measurements and concurrent measurements of neutral wind profiles from the Ionospheric Connection Explorer (ICON). We find that the Es occurrence rate is correlated with the negative vertical shear of the eastward wind, providing observational support for the wind shear theory.
Native soil bacteria and biocrust cyanobacteria inoculation improve seedling emergence of native plants on saline dryland soils 
Authors: Dadzie Frederick , Machado de Lima Nathali , Muñoz- Rojas Miriam
Published: March 2022

Soil salinity can result in osmotic and ionic stresses that critically impede seedling emergence, especially in drylands. Novel microbial-based technologies are emerging in the context of ecosystem restoration as a promising strategy to improve seedling establishment in saline environments. However, with recent concerns and the potential adverse impact of the use of exogenous microorganisms as bio-inoculants, much work is needed to develop groups of native microorganisms that can overcome soil salinity stress during restoration. In this study, we tested the effect of bio-inoculants individually composed of halophilic bacteria, biocrust cyanobacteria, and a consortium combination of both, on improving seedling emergence in soils with three salinity levels (low, moderate, and high salinity). Seedling emergence was assessed in four Australian native plants, Triodia epactia, Triodia pungens, Acacia ampliceps and Canavalia rosea, all inoculated with each of the inoculants and a control treatment without microbial inoculation. Our results showed that the highest seedling emergence was recorded in soils with low salinity, followed by moderate salinity soil and high salinity soil. Both Triodia spp. were severely impacted by salinity with very low emergence in all soil types. Acacia sp. emergence was higher when inoculated with halophilic bacteria in low and moderate salinity soils while Canavalia sp. emergence was higher under cyanobacteria inoculation in moderate salinity soils. Overall, our study shows that individual inoculation of halophilic bacteria and cyanobacteria improves the emergence of Acacia sp. and Canavalia sp. seedlings in low and moderate saline soils, while seedling emergence in high salinity soils can only be enhanced when using the combined consortia composed of halophiles and cyanobacteria. The analyses of the soil bacterial community composition by 16S rRNA gene amplicon sequencing showed that the inoculants did not negatively affect the resident bacterial soil communities. In conclusion, poor seedling emergence from salinity stress during the restoration of some plant species can be ameliorated with the inoculation of native halophilic bacteria and cyanobacteria. Grass species such as Triodia might need additional treatments to overcome salinity stress.
Optimality-based modelling of wheat sowing dates globally 
Authors: Qiao Shengchao , Harrison Sandy P. , Prentice I. Colin , Wang Han
Published: March 2022

Wheat sowing dates are currently used as an input for crop models that simulated wheat production. However, the optimal time for planting wheat will be affected by climate changes and human adaptations to these changes. In this paper, we present an optimality-based modelling approach, with additional constraints from low temperature and precipitation intensity, to estimate wheat sowing dates globally. This approach assumes that wheat could be sown at any time when the climate conditions are suitable, but the optimal sowing date that would be adopted by farmers would be that which maximises overall grain yields. We therefore run the model starting on every possible sowing date as determined by the climate constraints and then select the date which gives the highest yield in each location. We compare the modelled optimal sowing dates with an updated version of observed sowing dates created by merging census-based datasets and local agronomic information. Cold season temperatures are the major determinant of sowing dates in the extra-tropics, whereas the seasonal cycle of monsoon rainfall plays an important role in determining sowing dates in the tropics. The model captures the timing of reported sowing dates, with difference between estimated and observed sowing dates of less than one month (< 30 days) over much of the world;  maximum errors in tropical regions with large altitudinal gradients, such as Ethiopia, Bolivia and Peru, are up to two months. Discrepancies between the predictions and observations are larger in tropical regions than temperate and cold regions. Our approach for estimating optimal wheat sowing dates provides a way to examine human management decisions could mitigate the impacts of climate change on crop systems.
Thermal and hydraulic effects due to interaction between aquifer thermal energy storage systems
Authors: Bloemendal Martin , Duijff Rogier , Bakker Mark
Published: March 2022

Aquifer thermal energy storage (ATES) is a technology to provide energy-efficient heating and cooling to buildings by storage of warm and cold water in aquifers. In regions with large demand for ATES, ATES adoption has led to congestion problems in aquifers. The aquifer utilisation and the recovery of thermal energy stored in aquifers can be increased by reducing the distance between wells of the same temperature. Hence, this approach is implemented in practice, but the understanding of how this affects both the recovery efficiency and the needed pumping energy is missing.

In this research, the effect of well placement on the performance of individual systems is quantified using numerical modelling. Results show an increase in performance of individual systems when the thermal zones of wells of the same temperature are combined. The relative increase of the thermal recovery efficiency is 12% for average-sized systems with a storage volume of 250,000 m3/year, and 25% for small systems (50,000 m3/year). Performance of the combined system improves because the surface area of the thermal zone of the combined system, over which thermal losses occur, is smaller than the sum of the surface areas of the individual systems. Performance improvement is larger for systems with small storage volumes and long well screens. The optimal distance between wells of the same temperature is 0.5 times the thermal radius, following the trade-off between an increase of the thermal recovery efficiency and an increase in pumping energy. The distance between wells of opposite temperature must be larger than 3 times the thermal radius to avoid negative interaction.
Role of long-term/continuous erosion events versus extreme and rare events on long-term landscape evolution 
Authors: Litty Camille , Audin Laurence , Robert Xavier , Gribenski Natacha , Carcaillet Julien , Valla Pierre G. , Zerathe Swann
Published: March 2022

Erosion is a key parameter involved in the evolution of the Earth’s surface, and regulates the coupling between climatic and tectonic processes. The quantification of erosion at different spatial and temporal scales is a major challenge in earth sciences to better understand the nature and importance of these interactions. In addition, erosion processes are associated with significant natural hazards like landslides and debris flow. These relatively low-frequency but high-intensity events seem to play an important role in erosion budgets and in the long-term landscape evolution. It has been shown that rare and catastrophic erosion events can even dominate the long-term erosion rates. The aim of this study is to understand the respective role of long-term/continuous erosion dynamics versus extreme and rare events on long-term landscape evolution.

We focused on the ideal case of the western Peruvian Andes between Lima and Pisco (12°S and 13°S), where the hyper arid environment allows unequaled preservation of Pleistocene alluvial archives. This area presents several alluvial deposits including at least three mega-alluvial fans resulting from the upstream erosion of the western Andes and located at the outlet of the Rio Rimac in Lima, Rio Omas and Rio Cañete. These alluvial mega-deposits are mainly made up of rounded pebbles with a sandy matrix intercalated by sand lenses and levels of debris-flow deposits. To obtain the paleo-erosion rates from these deposits, we used in-situ produced cosmogenic 10Be concentrations in quartz and feldspar in deposits previously dated by Optically-Stimulated Luminescence (OSL) with ages ranging from 10 to 90 ka.

Our results show that the measured paleo-erosion rates differ depending on the type of deposits. In the fine grain debris-flow deposits, the paleo-erosion rates are of the same order of magnitude as the erosion rates measured in the current rivers, ranging from 10 to 100 mm/ka. But, paleo-erosion rates measured in conglomeratic deposits are ranging from 200 to 600 mm/ka and are therefore higher than erosion rates measured in both modern river sands and any debris-flow deposits. This shows that in order to precisely understand the governing erosional processes for a given context, it is necessary to constrain both the erosion rates responding to continuous and non-exceptional forcing (recorded in conglomerate deposits), and erosion rates related to extreme events recorded by low-frequency and high-intensity debris-flow deposits.
Classification of Circulation Types Associated with Freezing Precipitations in Bulgaria 
Authors: Nikolov Dimitar , Beck Christoph
Published: March 2022

Ice storms, caused by severe freezing rains and freezing drizzles are among the major weather hazards in winter. They influence seriously the air and ground traffic, disturb and even interrupt the distribution of electricity by snapping power lines or standstill the production from wind farms.

The conducted research had two main goals: conducting of an automatic classification of the weather types connected with freezing rains and freezing drizzles and assessment of the possible impact of the expected climate change tendencies on these events for the region of Bulgaria.

Data about 180 freezing precipitation events in the period 1958/59-2014/15 has been used and information for the classification has been taken from the six hourly reanalysis upper-air data for the same variables at five standard air pressure levels (1000, 925, 850, 700 and 500 hPa) from NCEP/NCAR reanalysis, which covers the same period.

Due to the large amount of the classification outputs, it was decided to focus on the classification approaches which already had given good results during a former investigation in COST 733 – these are the methods based on cluster analysis such as KMN, CKM and DKM k-means clustering.

Classifications have been made mainly for five standard air pressure levels and additional meteorological variables have been included as well. Following variables have been combined as the most important for the determination of freezing precipitation: see level pressure, air temperature at 850 hPa, the precipitation amount and the persistence of the event itself. Firstly, we have made classifications with 9, 18 and 27 classes but without including the event. We received 750 classifications, but with very low percentages of freezing precipitations among the classes.

After that we continued only with the DKM and KMN classifications. We have added the freezing precipitation events and have given different weights (from 0 till 1) of the variables and examining the behavior of the classifications. Increasing stepwise the percentage of freezing rains and freezing drizzles in the classes, we have established an upper. limit of 17 % with 206 classifications left.

After that χ2 -test has been applied to each class of these classifications in order to emphasis those classes with freezing cases which are not uniform distributed.

All used classifications have been evaluated by the means of different evaluation metrics such as frequency of the freezing precipitation cases in the classification classes, and correlation matrix of the classes. All of the classifications have been made using the software developed in COST Action 733.

The project was supported by the German Academic Exchange Service (DAAD).
Spatial and temporal characterization of wildfires, human and biophysical factors in Portugal
Authors: Pereira Mário , Parente Joana , Tonini Marj
Published: March 2022

Wildfires are uncontrolled fires that can burn the forest and agricultural parcels, semi-natural areas and wildlands (e.g., forests, scrublands and abandoned agricultural areas). The wildfire-prone regions in the world range from tropical savannahs to boreal forests, characterized by factors and conditions required for fire activity. In the last 20 years, wildfires were the 5th costliest and the 6th most frequent type of disaster in the world. In the same period, Europe experienced a high number of wildfires and burnt areas, mainly concentrated in the Mediterranean basin and with increasing trends in countries such as Portugal. The fire incidence presents high spatial and temporal (intra- and inter-annual) variability patterns associated with human activities, including land use/land cover changes, extreme weather conditions, climate variability and climate changes.

The objectives of this study include the identification and characterization of the spatial and temporal variability of wildfire incidence, as well as its main drivers, in Portugal. The study uses the most recent fire and environmental databases, analyses wildfires with different causes (e.g., negligent and intentional wildfires) and, in particular, the influence of weather and climate variability and extremes, namely heat waves (HW) and droughts (D) on the occurrence of large fires.

Obtained results comprise the spatial and temporal patterns of wildfires and the assessment of the main drivers of wildfires. We conclude that extreme weather conditions (HW and D) can explain the spatiotemporal patterns of large wildfires, which are responsible for the vast majority of the total burned area. Nevertheless, other factors (such as vegetation type, topography, distance to roads) can explain part of the variability patterns. Our findings are fundamental for forest, landscape, and wildfire management, as they include the identification and characterization of the areas and frame periods where fires are more frequent and have a greater impact. Additionally, this information, together with the identification of the nature of the main danger factors, can support monitoring and forecasting systems, aiming at the development of strategies for wildfire prevention, preparedness and response activities, as well as adaptation to climate change.

 

Acknowledgements:

This work was financed by the National Funds through FCT - Foundation for Science and Technology under the project UIDB/04033/2020. This work was also supported by the project FRISCO - managing Fire-induced RISks of water quality Contamination (PCIF/MPG/0044/2018), and funding attributed to the CE3C research center (UIDB/00329/2020).
Towards a community-led approach to improve the design of early warning systems and anticipatory action for flood risk preparedness
Authors: Mitheu Faith , Stephens Elisabeth , Tarnavsky Elena , Ficchi Andrea , Cornforth Rosalind , Petty Celia
Published: March 2022

As the world faces an uncertain future due to climate variability, environmental and climate change, and an increase in extreme hydrometeorological events, investing in early warning early action mechanisms can be an effective way to prepare and adapt to changes and extremes and reduce any impending impacts. Such an investment will require an understanding of the information needs of the users/user-groups, and in particular, the communities at risk, to ensure the design of tailored anticipatory actions, as well as an evaluation of how forecasts perform in detecting these extreme events and their impacts. This helps to ensure that flood-risk preparedness actions are better contextualised and not taken in vain. Community-led approaches for anticipatory action planning are based on the engagement with the communities at risk and can be an effective way of ensuring that: 1) the information needs of the specific user-groups are identified and integrated with the development of preparedness actions and plans; 2) data on loss and damages to lives and livelihoods can be used to demonstrate how reliable the forecasts are in informing early actions at the community level; and 3) gaps and challenges that hinder effective use of early warning information are identified across user-groups to help improve on the design and dissemination of early warning information. In this talk, we bring together information collected at the community and disaster management levels together with a recent evaluation of flood forecasts using impact (loss and damage) reports at a district level, to show how community-led approaches can help towards improving early warning mechanisms. By integrating global hydro-meteorological forecasts with information on crop calendars and impact reports collected from farmers and local communities, an enhanced impact-based flood early warning system focusing on crop impacts, as well as the natural hazard, is developed for a flood-prone district in Uganda (Katakwi).
Mapping NO2 pollution in Piedmont Region (Italy) using TROPOMI: preliminary results
Authors: Campus Adele , Acquaotta Fiorella , Coppola Diego
Published: March 2022

Recently, numerous agencies and administrations in their latest reports show how it’s impossible to overlook the negative impact of atmospheric air pollution on human health. In this regard, it’s essential to be able to understand the spatial and temporal distribution of the concentration of main pollutants, and its ways to change. Among the numerous strategies proposed to tackle this problem, from the ’70s the study of satellite data assumed a key role, extending the analyzes carried out only with ground tools.

In this work we analyzed the data acquired by TROPOMI (TROPOspheric Monitoring Instrument), a multispectral imaging spectrometer mounted onboard the ESA Copernicus Sentinel-5P satellite (orbiting since October 2017) and specifically focused on mapping atmospheric composition. In particular, we processed the TROPOMI NO2 products acquired over Piedmont Region (Italy) between 2018 and 2021.  We obtain preliminary results by comparing the satellite-derived tropospheric NO2 columns data with ground-based NO2 concentration acquired by the ARPA-Piemonte network in different urban and geomorphological contexts. In particular, we compared the TROPOMI-derived time series with the acquisitions of ground stations located in urban and suburban areas (e.g. in the city of Turin), identified as “traffic stations”, and in rural areas (low population density and countryside areas) identified as “background stations”. The results allow us to investigate the correlation and coherence between the two datasets and discuss the added values and limits of satellite data in different environmental contexts, with the prospective of providing NO2 concentration maps of the Piedmont Region.
Spread tsunami impact in East Tunisia contemporaneous of the CE 365 Crete earthquake
Authors: Bahrouni Nejib , Meghraoui Mustapha , Bayraktar Hafize Başak , Lorito Stefano , Zagrarni Mohamed Fawzi , Polonia Alina , Bel Mabrouk Nabil , Kamoun Mohamed , Khadraoui Afef , Kamoun Fekri
Published: March 2022

New field investigations along the East Tunisian coastline reveal sedimentary deposits and damaged localities that may account for a catastrophic event during late Holocene. North of Sfax - Thyna city (at Henchir El Majdoul site) ~3.4 m high cliff coastal marine and alluvial terraces show a 20 to 50-cm-thick chaotic layer with sandy coarse gravels mixed with limestone beach-rocks, reworked blocks, broken shells of marine and lagoon gastropods and lamellibranch mollusks, organic matter, and Roman pottery. The chaotic layer truncates a succession of sandy-silty paleosol, covers Roman settlements and is overlain by fire remains and a relatively thin (~10 cm) sandy-silty aeolian unit and ~1-m-thick alluvial deposits. Charcoal samples collected at 10 cm below and 4 cm above the catastrophic deposits provide radiocarbon dating that brackets a catastrophic event between 286 and 370 CE (2s). Beside the damaged Roman site of Thyna, other localities of the east Tunisian coastline such as Neapolis (Nabeul) near Tunis, Hadrumete (Sousse), Meninx-town in Girba (Djerba), Wadi Ennouili (Gulf of Gabes), and Sabratha (in Libya) experienced major damage and abandonment of sites in Fifth century. The extent of damage from northern Libya to northern Tunisia at the Fourth century and radiocarbon dating, added to the 2.6 m thick turbidite deposits west of Malta correlate with the major tsunamigenic earthquake of 21 July 365 (Mw ~ 8) in west Crete (Greece). Numerical modelling of the tsunami caused by an earthquake in the Hellenic Arc subduction zone suggests more than 3.5 m high tsunami waves propagation affecting the Tunisia coastline, resulting in a run-up consistent with the stratigraphic evidence presented here. The catastrophic deposits, offshore-onshore correlations, archeological damage and modelling of tsunami waves suggest a new, higher-resolution, assessment of the tsunami hazard leading to a better estimate of tsunami risk on the eastern coast of Tunisia.