bluuebunny/crossref_metadata_2025 huggingface dataset:
Concern and anticipation of future sea-level rise increase potential for social tipping interventions
Authors: Smith Keith , Wiedermann Marc , Donges Jonathan , Heitzig Jobst , Winkelmann Ricarda
Published: March 2021

Effective climate change mitigation necessitates swift societal transformations in order to meet the goals of the Paris Accord and to prevent abrupt, irreversible, transitions in the Earth System. Social tipping processes, where relatively small groups trigger sudden qualitative shifts in collective behaviour have been identified as a potential key mechanism instigating these necessary transformations.  However, the specific processes whereby experienced or anticipated future climate impacts effect large-scale societal changes remain largely unidentified and underrepresented in contemporary Earth System models. Here, we combine output from the MAGICC climate model, country-level social survey data and a low-dimensional network-based threshold model of social tipping to exemplify a transformative pathway in which climate change concern increases the potential for social tipping and extended anticipatory time horizons of future sea level rise shift the system closer towards a critical state whereby interventions, such as emergent social movements or policy change, can ultimately kick the system into a qualitatively different state. While dynamics of climate tipping elements are often reduced to a single control parameter, our findings suggest that such an approach may be inapplicable for social tipping processes, as single parameters alone may not reach critical thresholds required for tipping. Instead, we show that comparatively smaller changes in a set of multiple parameters can suffice to shift a system into its critical state where ephemeral (potentially deliberate) kicks can bring about social tipping. Tipping in the climate system is commonly associated with bifurcations, while social tipping processes are instead more likely induced by sudden events or shocks, where the required magnitudes of such kicks emerge from multiplicative, interacting factors. Effective analyses of such processes therefore requires novel modeling paradigms, specifically accounting for the increased complexity of socio-economic systems.
Passive seismic interferometry of the ultraslow-spreading Southwest Indian Ridge 
Authors: Mohamadian Sarvandani Mohamadhasan , Kästle Emanuel , Boschi Lapo , Leroy Sylvie , Cannat Mathilde
Published: March 2021

Passive seismic interferometry (ambient-noise seismology) is an increasingly popular, eco-friendly, relatively inexpensive exploration geophysics tool, to map S-wave velocity in the Earth’s crust. This method has not yet been applied widely to marine exploration. The purpose of this study is to investigate the crustal structure of a quasi-amagmatic portion of the Southwest Indian Ridge by interferometry, and to examine the performance and reliability of interferometry in marine exploration. To achieve this goal, continuous vertical-component recordings from 43 ocean bottom seismometers (OBS) deployed during the SISMO-SMOOTH cruise (2014) were utilized. Recorded signals span frequencies between 0.1Hz and 3Hz. We show that reliable estimates of the Green’s function are obtained for many station pairs, by cross-correlation in the frequency domain. The comparison of the cross-correlations with the theoretical Green’s (Bessel) function provides one Rayleigh-wave dispersion curve per station pair; dispersion curves are then averaged, and inverted through a conditional neighborhood algorithm to determine a 1D S-wave velocity model, that we estimate to be well constrained within the crust. Our S-wave velocity model is analyzed and interpreted with geological information, and independent geophysical studies in the region of interest, as well as other areas characterized by similar tectonically-dominated, quasi amagmatic spreadings.
Cosmovision and geothermal: proposal for direct uses of the geothermal resource
Authors: Elizalde Karla , Jácome  Paz Mariana Patricia , Zárate Arroyo Alma Adriana
Published: March 2021

Cosmovision and geothermal: proposal for direct uses of the geothermal resource in El Carrizal, Veracruz, México

Keywords:  Geothermy, direct uses, resource, social analisis.

Currently there is a wide epistemological repertoire that tells us about the man-natural environment relationship, the close relationship that exists between these two entelechies has been the subject of controversy within scientific disciplines, and it is not possible to speak of man without a time and space, just as you cannot talk about space and its components without mentioning at some point the presence of man.

This close relationship between man and nature has evolved over time, going from a static concept to a dynamic one in response to the need to offer an explanation of how the natural environment with anthropic presence has been modified and used.

Geothermal energy plays a very important role, from the energy field to the tourist, forming part of our civilization and history, with which it has a wide historical and cultural background. That is why, at present, geothermal energy appears as an important solution for obtaining renewable, sustainable, accessible and low-cost ecological energy throughout its temperature range.

 

The main limiting cause for planning and carrying out an integral project of direct uses of the thermal resource is the lack of research work on thermal manifestations, where the geological and geochemical characteristics are described and which are integrated into a social analysis that tells us about perception of geothermal resources and the cultural and identity value that the adjacent population grants.

This panorama is repeated throughout the Mexican territory, and in particular, in the vicinity of the state of Veracruz and its various thermal springs, an example of this are: Los Baños Carrizal (Apazapan, Ver., 19 ° 19´ 15.69” N - 96 37´43.94” W), Hotel Chichaki (Apazapan, Ver., 19 ° 19´31.54” N - 96 ° 43´24.11” W), Isabelass Spa (Loc.Tinajitas, Actopan, Ver., 19 ° 37´ 38.07” N - 96 ° 27´31.87” W), among others.

In this work will present  the preliminary results of the project that leads to the realization of a geochemical characterization and the elaboration of a social study that manages to understand the role that the different thermal manifestations play around the history and culture of the population and with this to reach the proposal of a project of direct uses of the geothermal resource.
Introduction of legume cover crops practice in intensive grain corn crop system to mitigate soil threats in the Mediterranean region
Authors: Boulet Anne Karine , Alarcão Carlos , Ferreira Carla , Veiga Adelcia , Campos Lara , Ferreira António , Hessel Rudi
Published: March 2021

In Portugal, grain corn is the main cereal produced, comprising 56% of total cereal yield. It is grown in intensive monoculture cropping systems that may have negative effects on soil quality, affecting long-term fertility and productivity, and therefore the sustainability of production. A promising management practice to mitigate soil degradation is to grow a cover crop during the usual fallow period. This study examined in which extend six species of legume cover crops (forage pea (pisum sativum L), yellow lupin (lupinus luteus), crimson clover (trifolium incarnatum), balansa clover (trifolium michelianum), persian clover (trifolium suaveolens), and arrowleaf clover (trifolium vesiculosum) are suitable to mitigate soil threats in grain corn systems specifically in the Mediterranean region. Specific objectives were to identify the effectiveness of the legume 6 species in improving soil fertility (i.e., soil organic matter content), mitigating nutrient leaching, nutrient recycling, and weed control. The study was performed in the lower Mondego valley in central Portugal. It covered two autumn to spring periods of cover crop cultivation, and assessed changes in soil fertility, dry biomass yield of legumes and weeds, and their associated nutrient content (total nitrogen-phosphorus-potassium).

In general, the six legume cover crops (LCC) species showed good adaptation to Mediterranean conditions, yielding large amounts of biomass (up to 8 ton/ha for clovers species). At the short term, LCC incorporation into the soil had no clear effect in soil organic matter content. The median uptake of NPK macronutrients for all species was high respectively 176-20-172 kg/ha, due to their generally high biomass production, highlighting their great potential to mitigate nutrient leaching. The capacity of the LCC to provide green manure services enabled a median reduction of 40% of N, 60% of P, and 100% of K supplied by mineral fertilizers necessary to attain a corn grain yield of 12t/ha. LCC showed a good effectiveness in weeds control, although only in the second year of the study. Three clover species (crimson, balansa, arrowleaf) performed best in terms of weed control maintaining weed production below 0.5 ton/ha, vs 3-4 ton/ha in control plots, due to early establishment and/or high biomass production in later growth stages, and avoiding the first application of herbicide in pre-emergent herbicide for grain corn cultivation.
3D modeling of UK Coastline using social media data for landslide mapping and monitoring
Authors: Todowede Sewedo , Manzella Irene
Published: March 2021

The ubiquitousness of social media has created a valuable and massive amount of data relating to real-live events which are being explored to investigate a wide range of phenomena including, disaster monitoring, health surveillance, user sentiments, etc. For events such as landslide, which mostly occur in remote and localized areas, social media provide an opportunity to expand landslide mapping beyond the current approach.

Traditional sources of landslide events are via media reports, scientific articles, or aerial photography, thus, limiting landslide mapping to only areas where such resources exist. This is followed by repeated in-situ measurements with equipment such as LIDAR to create a 3D geomorphological model of the landslide. At locations with poor accessibility or hazardous conditions, mobilizing personnel and equipment to the site is often impossible. The financial implication of repeated field operations also means landslide monitoring programs are prioritized. These deficiencies have hampered the generation of a robust landslide inventory which is the crucial tool for understanding past landslides and developing an effective system for managing future landslides.

This study demonstrates the application of social media analytics for the identification and modeling of landslides along the South West coast of the UK. From the analysis of over 100,000 tweets, 23 landslide events reported by Twitter users are identified. Five (5) of these events have not been previously reported. Also, drone videos obtained from Twitter and YouTube were processed using Structure from Motion-Multiview Stereo (SFM-MVS) photogrammetry techniques to create a 3D model of landslides at five (5) selected locations.

Analysis of the 3D model created at one of the locations shows that an estimated 1480 m3 of earth material was removed from the landslide due to the impact of Storm Dennis and Storm Ciara events of the 8th – 9th and 15th -16th of February 2020 respectively, while an estimated 295 m3 was retained at the base of the landslide, possibly an effect of the landslide control/stabilization installation.

The result from this study shows the potential of social media to expand landslide coverage in the UK and to provide a high-resolution 3D model at minimum cost. These data can be used to monitor landslide evolution and to assess their hazard.
Great circle analysis of South American VGP-distributions suggests widespread Cretaceous remagnetizations: case study of the Itararé Group Rocks from Brazil
Authors: Bilardello Dario , Callebert William , Davis Joshua
Published: March 2021

South American Jurassic/Cretaceous rocks has been troubled by elongated virtual geomagnetic pole (VGP) distributions, while many discordant poles from the Carboniferous to the Triassic have also been recognized, rendering the South American apparent polar wonder path (APWP) problematic. 

We have conducted a paleomagnetic study of the sedimentary Permo-Carboniferous Itararé Group rocks within the state of São Paulo, Brazil, including three intruding mafic sills that are attributed to Early Cretaceus magmatic activity. The site-mean VGP distributions obtained from the sedimentary rocks define elongations that include the VGPs of the mafic intrusions, and are interpreted as remagnetization paths toward the directions characteristic of the sills. These interpretations are supported by extensive rock-magnetic data that provide a viable mechanism for the secondary magnetizations. Careful analysis of the paleomagnetic data of the sedimentary rocks enables isolation of a primary VGP distribution that is consistent with the reference Carboniferous pole position.

Analysis of other Carboniferous to Triassic South American paleomagnetic VGPs reveals that the majority of these data are also elongated: regardless of the age of the rocks, the elongations dominantly intersect at the location of the Late Cretaceous reference pole, and a second location similar to the intersection of the VGP elongations of some Jurassic/Cretaceous rock formations, and also coincides with the cusp of the debated loop in the Carboniferous-Triassic APWP. Based on multiple lines of evidence, we interpret the elongations and their intersections to reflect remagnetizations that occurred as a result of the widespread magmatism associated with the opening of the South Atlantic. We suggest that the extent of the remagnetizations is formation-specific, and that other rock-formations should be carefully re-evaluated.
Regional infrasound monitoring in Ukraine
Authors: Liashchuk Oleksandr , Kariahin Yevheniy , Andrushchenko Yuriy , Tolchonov Ivan , Kolesnykov Leonid
Published: March 2021

The infrasound network in Ukraine is represented by three infrasound arrays in Kamenets-Podilsky, Malin, and Gorodok. Also, additional single sensors are installed near Odesa, Kharkiv, and Zhytomyr. A total of 6 infrasound arrays are expected to be deployed. Condenser-type microbarographs are installed everywhere, a wind noise reduction system is available for each. The main task of the network is to monitor technogenic and natural activity and emergencies. At the same time, such a dense enough network can be successfully used to study the characteristics of the atmosphere. All registered digital data IS sent to the server of the National Data Center, where it automatically processed using algorithms F-statistics. The results of processing are available to the analyst in the operational database, where he rejects signals according to the criteria of speed, duration, and period. Also, at this stage provided a comparison between acoustic signals and seismic events. If necessary, additional processing of infrasound data is carried out using the PMCC. For powerful events, data from IMS CTBTO stations are also taken into account. If it is possible to identify an event using additional information, this is done (for example, media monitoring, reports of mining enterprises). As a result, the final bulletin is formed. The overwhelming number of registered signals of an explosive origin due to the work of the mining industry, technogenic accidents, and military operations. A number of signals from fireballs were recorded. Refinements using atmospheric models had not been carried out before, this practice started only this year. The results obtained can be used for a preliminary assessment of the potential of the regional infrasound network.
Remotely-controlled ice-nucleating particle measurements from the Eastern North Atlantic during autumn and winter
Authors: Wilbourn Elise , Hiranuma Naruki , Lacher Larissa , Nadolny Jens , Möhler Ottmar
Published: March 2021

Ice-nucleating particles (INPs) are aerosol particles that catalyze the heterogeneous formation of ice crystals under ice supersaturation conditions. These INPs can change cloud characteristics on wide spatiotemporal scales, including albedo and radiative effects, as well as precipitation types and amounts, thus affecting both weather and climate. However, INP measurements with reasonable temporal resolution have been challenging in terms of both technology and logistics in our research community. Here we present preliminary results of our recent six-month effort from the Eastern North Atlantic (ENA) field campaign to advance the research and explore remote operation of the plug-and-play Portable Ice Nucleation Experiment (PINE) chamber to semi-autonomously measure marine boundary layer INP concentrations. In this campaign we deployed our PINE chamber at the U.S. Department of Energy Atmospheric Radiation Measurement (DOE ARM) ENA site on Graciosa Island, Azores (39° 5′ 29.76″ N, 28° 1′ 32.52″ W). The PINE chamber has been continuously operated since October 2020 with supervision and periodic remote maintenance by scientists in West Texas. The INP measurements were conducted at mixed-phase cloud conditions at temperatures between -14°C and -33°C. These measurements, along with other aerosol particle and meteorological measurements made by a suite of instruments collocated at the DOE ARM site, give unique insights on the response of INP concentrations to local and mesoscale dynamics and thermodynamic processes. This study provides the first remote and continuous INP measurements over two meteorological seasons made in the ENA region within the marine boundary layer, giving insights into an area with prominent marine influences on aerosol populations. Graciosa Island is a small island (only 61 km2) surrounded by oligotrophic oceans, and these measurements were made during the most biologically productive time of year for phytoplankton in the surrounding ocean waters. The long-term and continuous nature of these measurements allows a unique comparison of marine biological productivity, using satellite-derived chlorophyll a as a proxy for biomass, and INP concentrations. The median INP concentrations at -25 °C and -30 °C were around 4 INP L-1 and 27 INP L-1 respectively. Our preliminary data suggest that INP concentrations measured by the PINE chamber at the ENA site are comparable to other studies at locations with primarily marine INPs. More details will be offered in our presentation.
Using the IPCC for Communicating Both the Full Extent of the Global Climate Emergency and the Required Response
Authors: Carter Peter
Published: March 2021

Since the IPCC (2018) 1.5°C Report, the climate emergency is widely recognized. Then 2019 COP25 statement by IPCC Chair Dr H. Lee ,referring to the three recent IPCC Special Reports (2018,2019,2019) is crucial emphasizing that global emissions MUST decline by and from 2020. The Summaries for Policy Makers (SPMs) are convincing for communication as all world governments approve them. Though the IPCC assesses climate change, the environmental health emergency called climate change is climate system disruption from atmospheric greenhouse gas pollution. The IPCC assessments can be used to produce risk assessments. IPCC published climate change science reports are invaluable, especially the FAQs. The most important message in the IPCC (2014) AR5 and 1.5°C Report is that global emissions have to decline rapidly from 2020, via market failure corrections, for a 1.5°C and for a 2°C limit. The greatest impact to humanity is on food security, and from the IPCC we describe regional crop impacts and crop model limitations. We elucidate IPCC reports on confidence, carbon budget, net zero, negative emissions, value judgements, and recommendations. We clarify inertias, commitment, risks, and amplifying feedbacks. Long-term data trends, rather than only model projections, can now be relied on. We relate IPCC scenarios to worst-case, business-as-usual and best case. For risk we use the IPCC upper ranges, because long-term projected temperature increases are underestimated as they do not account for amplifying feedbacks or decline of carbon sinks, and are only based on a single median climate sensitivity (3C). Although the IPCC shows that atmospheric CO2 is "forever," IPCC SPM projections are all now only to 2100.  From the IPCC RCP scenarios the world is tracking closest to the worst case scenario (RCP8.5). On this scenario the IPCC 1.5°C Report projects 1.5°C by 2035 and 2°C  by 2047. The greatest risk to the future of humanity and most life is multiple inter-reinforcing amplifying feedbacks that lead to hothouse Earth and on to runaway. The evidence for multiple Arctic feedback emissions and Amazon die-back can be found in the IPCC 2014 5th assessment. This reinforces the imperative requiring immediate and rapid global emissions decline. 
Marine Heat Waves in the Peruvian Upwelling System: from 5-day localized warming to year-long El Niños
Authors: Pietri Alice , Colas François , Rodrigo Mogollon , Tam Jorge , Gutierrez Dimitri
Published: March 2021

Extreme climatic events, such as marine heatwaves (MHWs), have been shown to globally increase in frequency and magnitude over the last decades, and can disrupt ecosystems significantly. Coastal upwelling systems, because they are biodiversity hot-spots and socioeconomic hubs, are particularly vulnerable to those rapidly developing anomalously warm marine events. The Peruvian coastal system in particular is highly exposed to climate variability because of its proximity to the equator. As such it is regularly impacted by El Niño events whose variability has been related to the longest and most intense MHWs in the region. However the intensively studied El Niño events tend to overshadow the MHWs of shorter duration that also have an important impact on the coastal environment as they can trigger other extreme events such as nearshore hypoxias and harmful algal blooms. 

Using 38 years of satellite sea surface temperature data, we investigate the characteristics (spatial variability, frequency, intensity and duration) and evolution of MHWs in the South Tropical Eastern Pacific, with a focus on the Peru Coastal Upwelling System. The separation of events by duration allows to identify a spectrum, from El Niño events to shorter scale MHWs. Results show that the statistical  distribution of MHWs properties, their spatial organization and preferential season of occurrence varies significantly in function of their duration. Besides, when removing large El Niño events, an increase of occurrences, duration and intensity is observed over the last 38 years, contrary to the reduction that is observed in the region when considering all MHWs. Finally, the possible drivers are discussed to disentangle the role of the local (wind stress) and remote (equatorial variability) forcing in function of the events duration.
Development of stochastically perturbed parameterization scheme for the Noah Land Surface Model with the optimized random forcing parameters using the micro-genetic algorithm
Authors: Lim Sujeong , Cassardo Claudio , Park Seon Ki
Published: March 2021

The ensemble data assimilation system is beneficial to represent the initial uncertainties and flow-dependent background error covariance (BEC). In particular, the inevitable model uncertainties can be expressed by ensemble spread, that is the standard deviation of ensemble BEC. However, the ensemble spread generally suffers from under-estimated problems. To alleviate this problem, recent studies employed stochastic perturbation schemes to increases the ensemble spreads by adding the random forcing in the model tendencies (i.e., physical or dynamical tendencies) or parameterization schemes (i.e., PBL, convective scheme, etc.). In this study, we focus on the near-surface uncertainties which are affected by the interactions between the land and atmosphere process. The land surface model (LSM) provides various fluxes as the lower boundary condition to the atmosphere, influencing the accuracy of hourly-to-seasonal scale weather forecasting, but the surface uncertainties were not much addressed yet. In this study, we developed the stochastically perturbed parameterization (SPP) scheme for the Noah LSM. The Weather Research and Forecasting (WRF) ensemble system is used for regional weather forecasting over East Asia, especially over the Korean Peninsula. As a testbed experiment with the newly-developed Noah LSM-SPP system, we first perturbed the soil temperature — a crucial variable for the near-surface forecasts by affecting sensible heat fluxes, land surface skin temperature and surface air temperature, and hence lower-tropospheric temperature. Here, the random forcing used in perturbation is made by the tuning parameters for amplitude, length scale, and time scales: they are commonly determined empirically by trial and error. In order to find optimal tuning parameter values, we applied a global optimization algorithm — the micro-genetic algorithm (micro-GA) — to achieve the smallest root-mean-squared errors. Our results indicate that optimization of the random forcing parameters contributes to an increase in the ensemble spread and a decrease in the ensemble mean errors in the near-surface and lower-troposphere uncertainties. Further experiments will be conducted by including soil moisture in the testbed.
Sulfur isotope evidence of geochemical zonation of the Samoan mantle plume
Authors: Dottin James , Labidi Jabrane , Jackson Matthew , Farquhar James
Published: March 2021

The radiogenic Pb isotope compositions of basalts from the Samoan hotspot suggest various mantle endmembers contribute compositionally distinct material to lavas erupted at different islands [1]. Basalts from the Samoan islands sample contributions from all of the classical mantle endmembers, including extreme EM II and high 3He/4He components, as well as dilute contributions from the HIMU, EM I, and DM components. Here, we present multiple sulfur isotope data on sulfide extracted from subaerial and submarine whole rocks associated with several Samoan volcanoes—Malumalu, Malutut, Upolu, Savaii, and Tutuila—that sample the full range of geochemical heterogeneity at Samoa and allow for an assessment of the S-isotope compositions associated with the different mantle components sampled by the Samoan hotspot. We observe variable S concentrations (10-1000 ppm) and δ34S values (-0.29‰ to +4.84‰ ± 0.3, 2σ). The variable S concentrations likely reflect weathering, sulfide segregation and degassing processes. The range in δ34S reflects mixing between the primitive mantle and recycled components, and isotope fractionations associated with degassing. The majority of samples reveal Δ33S within uncertainty of Δ33S=0 ‰ ± 0.008, suggesting Δ33S is relatively well mixed within the Samoan mantle plume. Important exceptions to this observation include: (1) a negative Δ33S (-0.018‰ ±0.008, 2σ) from a rejuvenated basalt on Upolu island (associated with a diluted EM I component) and (2) a previously documented small (but resolvable) Δ33S values (up to +0.027±0.016) associated with the Vai Trend (associated with a diluted HIMU component) [2]. The variability we observed in Δ33S is interpreted to reflect contributions of sulfur of different origins and likely multiple crustal protoliths. Δ36S vs. Δ33S relationships suggest all recycled S is of post-Archean origin. The heterogeneous S isotope values and distinct isotopic compositions associated with the various compositional trends confirms a prior hypothesis; unique crustal materials are heterogeneously delivered to the Samoan mantle plume and compositionally influence the individual groups of islands.

[1] Jackson et al. (2014), Nature; [2] Dottin et al. (2020), EPSL
Solar activity and its impact on the mid-latitude trough during geomagnetic storms
Authors: Przepiórka Dorota , Matyjasiak Barbara , Chuchra Agata , Rothkaehl Hanna
Published: March 2021

Mid-latitude trough (MIT) is the distinct structure observed in Earth’s ionosphere at high latitudes especially at the nighttimes. The phenomenon is observed at both hemispheres. As it resides at the topside ionosphere in the sub-auroral region, its behaviour and properties are highly sensitive to the solar and geomagnetic activity. Generally as the geomagnetic activity is more pronounced the MIT is observed at lower latitudes, it also deepens and becomes much more distinct in comparison to the low magnetic activity periods. MIT responds as well to the rapid changes in geomagnetic conditions, as are the geomagnetic storms, mainly caused by the CMEs. 

Based on the observations gathered by DEMETER data between 2005 and 2010 years  we present a set of geomagnetic storm cases and how the MIT properties has been changing as the storm evolves. We also discuss how it corresponds to the current solar activity and their evolutionary history  described by a set of different parameters.
Synthetic and Comparative Hydrology of Earth, Mars, and Titan
Authors: Cuřín Vojtěch , Blöcher Johanna , Brož Petr , Markonis Yannis , Masner Jan , Pavlík Jan , Solomonidou Anezina , Šeborová Nikola
Published: March 2021

Earth, Mars, and Titan are the only known planetary bodies in our solar system where flowing liquids have shaped surface topography and formed extensive river networks. Fed by atmospheric precipitation and carved by fluvial erosion, these channels are observable in remote sensing data. They carry information about the interactions between the atmosphere, the hydro(carbon)sphere, and the lithosphere and allow for investigation of the conditions that had prevailed during their formation. Comparison of drainage basins, which developed in these profoundly different environments, could yield insights into the past and ongoing hydrological processes in addition to climatic, chemical, and topographic conditions of the planetary bodies. Increased computing capacities allow for building and utilization of a vast database of hydrological, climatological, and geological data as well as algorithmic evaluation of remote sensing products. Here, we propose a classification of basins from Earth, Mars, and Titan using several machine learning techniques based on their morphological characteristics, network properties, spatial homogeneity, cross-scale self-similarity, and visual properties. Constraints on climatic and geologic properties of the terrestrial basin classes will be identified, and the results of their morphology-climatic relationship extrapolated to Mars and Titan. To find out more, visit our project’s website https://www.schemata-project.com/.
High-resolution futuristic climate forcing over semi-arid catchments. Case of the Tensift (Morocco)
Authors: Moucha Ahmed , Hanich Lahoucine , Tramblay Yves , Saadi Amina , Gascoin Simon , Martin Eric , Lepage Michel , Szczypta Camille , Jarlan Lionel
Published: March 2021

In the south Mediterranean catchments, most of the available water resources are used to produce hydro-electric energy, for drinking water as well as for irrigated agriculture located downstream in the surrounding plains. This water Tower role is today threatened by the increase in water needs relative to the growth of the population and its standard of living, by the intensification of irrigated agriculture and by climate change. The south Mediterranean region is now well known as a “hot-spot” for the latter and there is reasonable evidence showing that mountainous region should face enhanced warming compared to the surrounding plains in the future. In this context, the development of a high-resolution futuristic climate forcing on the Tensift catchments. Based on the high-resolution SAFRAN reanalysis developed in the study presented above. is very important for the study of the climate, with a trend for the 2041-2060 horizon. For this purpose, we used future climate scenarios provided by the Euro-CORDEX program evaluated over the region. To achieve this objective, two RCP runs at 12 km resolution are downscaled using the quantile-quantile approach based on temperature and precipitation acquired at the Marrakech station in the plain and at the Oukaimeden station located at an altitude of 2687m in the High Atlas. It is shown that higher warming is expected on the mountainous region than in the plain station (2.8°C versus 2.3°C for the maximum temperature and 2.8° versus 2° for the minimum temperature; scenario RCP8.5 for 2041-2060). The higher warming on the minimum temperature may drastically impact the snow/rain partition in the high Atlas. Based on these disaggregated climate scenarios, future spatialized forcing are built from the correction functions obtained at the two above-mentioned plain and mountain stations and the SAFRAN re-analysis. The mountainous area is expected to face a higher increase of air temperature than in the plain, reaching +2.5°C for RCP8.5 and +1.71°C for RCP4.5 over 2041-2060. This warming will be accompanied by a marked decrease in precipitation (-16% for RCP8.5). this future spatialized data set is to be used within impact studies, in particular concerning water resources.
Multiplatform observation of cyclonic eddies during the REEBUS experiment
Authors: Fischer Tim , Karstensen Johannes , Dengler Marcus , Bendinger Arne
Published: March 2021

During the collaborative project "Role of Eddies in the Carbon Pump of Eastern Boundary 

Upwelling Systems" (REEBUS), that took place in the eastern tropical North Atlantic in 2019, 

three cyclonic mesoscale eddies were intensely surveyed by ship and autonomous systems. The 

three eddies were located at different distances to the coast, the most intense of them 

(vorticity about 0.5 times f) was found in lee of the Cabo Verdian island of Fogo. Here we 

present the reconstruction of the 3-D structure for the three eddies from ship ADCP and 

hydrographic sections. Divergence estimates suggest the existence of a downwelling cell in the 

center of all three eddies. This cell extends from below the thermocline down to some hundred 

meters, at a diameter of about 10 nautical miles. Surface signatures of the eddies indicate 

elliptic and oscillating behavior which is further investigated using the interior ocean data. 

In this work we also explore the limitations of section-based ocean mesoscale eddy 

reconstructions.
Assessing the water resources vulnerability of Ouergha catchment under climate change projection
Authors: Mounir Kaoutar , Sellami Haykel , El Ghoul Imen , El Khanchoufi Abdessalam , La Jeunesse Isabelle
Published: March 2021

Climate change scenarios predict water scarcity in Mediterranean region, particularly in areas that are exposed to weather related disasters (drought, flood...) (IPCC, 2014). These changes will most likely impact food security by altering the hydrological cycle and water availability. Considering that water is the economic engine of the Mediterranean countries that rely especially on agricultural production, several studies have been focused on understanding and quantifying the climate change effects on hydrological regime. In addition, the complexity of these impacts can be due also to a bad resources management that can hinder the countries’ development (Marin M., 2020). To study the hydrological function of the Ouergha watershed, the SWAT model was used to simulate daily runoff response for the period 1997-2017, including three years (1993-1997) for the warming-up of the model. Calibration and validation of the model were applied for the period 1997-2017 using the SUFI-2 algorithm, and the simulation estimates the water flows of the Ouergha basin in a monthly time step. The water balance indicates a predominance of evaporation losses accounting for 41% of total rainfall. Runoff represents 8% of precipitation while lateral flow is 7%. The remainder is distributed between the 5% deep aquifer recharge and percolation, in addition to the flow to the river which represents about 39%. The Swat model is considered as suitable tool for the management of water resources even though under changing climatic conditions, it’s prone to errors and uncertainties that needs to be assessed to make full benefits from this model challenging (Sellami H., 2014).To analyze these uncertainties a modelling approach based on the combination of hydrological model and a set of high resolution CORDEX climate models has been developed. The results are considered as a decision-making tool for local and regional actors.

References :

IPCC. (2014). Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Core Writing Team, R.K. Pachauri and L.A. Meyer (eds.)]. IPCC, Geneva, Switzerland, 151 pp.

Marin M., C. L. (2020). Assessing the vulnerability of water resources in the context of climate changes in a small forested watershed using SWAT: A review. Environmental Research,. doi:https://doi.org/10.1016/j.envres.2020.109330.

Sellami H., L. J. (2014). France), Uncertainty analysis in model parameters regionalization: a case study involving the SWAT model in Mediterranean catchments (Southern. Hydrology and Earth System Sciences, 18, 2393–2413. doi:doi:10.5194/hess-18-2393-201.
Spontaneous formation of waves, channels and levees in geophysical mass flows
Authors: Gray Nico
Published: March 2021

Geophysical mass flows often break down into large amplitude wave pulses and/or spontaneously form channels with static levees in the arrest zone, enhancing overall run-out. This talk reviews recent depth-averaged models that are able to capture the formation of:- (i) rollwaves, (ii) erosion-deposition waves (which exchange mass with an erodible substrate) and (iii) channel and levee formation, within a single framework. The key is the inclusion of frictional hysteresis, which allows static and moving zones to coexist, as well as depth-averaged viscous terms that incorporate further details of the granular rheology. As well as being able to compute time-dependent spatially evolving solutions numerically, the resulting model allows steady-state solutions to be constructed for the height, width and depth-averaged velocity profile across a leveed channel, which are in good quantitative agreement with small scale analogue experiments using monodisperse dry sand. Colour change experiments are used to show that erosion-deposition waves really do propagate downslope as a wave, rather than a coherent body of grains, and that the presence of the erodible substrate gives them surprising mobility over very long distances. Photos and videos of the similar effects at field scale will be shown to emphasize the importance of these ideas for a wide range of geophysical mass flows. There are, however, still many open challenges in how to generalize these results to multiphase mixtures with broad grain size distributions.
Farley Buneman instabilities in the Auroral region: Continuous kinetic and hybrid simulations.
Authors: Rojas Enrique , Hysell David
Published: March 2021

Farley-Buneman instabilities generate a spectrum of field-aligned plasma density irregularities in the E region. Although fully kinetic particle-in-cell simulations offer a comprehensive description of the underlying physics, its computational cost for studying non-local phenomena is tremendous. New methods based on hybrid and continuous approaches have to be explored to capture non-local physics.

In this work, we present new developments on a continuous solver of Farley-Buneman waves. We compare the performance of fully kinetic (continuous), hybrid, and fluid models. Furthermore, we investigate phase speed saturation, wave turning effects, and dominant wavelengths and assess how well these correspond to radar measurements. Finally, we describe some initial attempts at constructing simple surrogate models to capture the dominant microphysics of these simulations.
The Great Oxidation Event can be detected and dated through the genetic record
Authors: Magnabosco Cara
Published: March 2021

Traditionally, the biogeochemical information preserved in the rock record has been used to study the environmental conditions of Earth’s past. There is however another important record of Earth’s history that is only just beginning to be explored: the genomes of contemporary organisms (i.e. the genetic record). The genetic record is an under-utilized tool for studying Earth History. Like the rock record, the genomes of microorganisms have been imprinted with information regarding our changing planet. In this presentation, we will describe a framework for accessing and interpreting the “genetic scars” imprinted on the genomes of microorganisms to identify the timing of the Great Oxidation Event (GOE) independent of the geochemical record. This approach combines ideas from systems biology and data science to infer the timing of major changes in the evolution of microbial lineages and metabolic pathways. Briefly, a horizontal gene transfer constrained molecular clock provides timeline for major speciation events within the bacterial tree of life which can be used to date the emergence of specific protein families related to oxygenic photosynthesis and oxygen consumption. A feature selection algorithm for metabolic networks allows us to generalise this technique beyond the GOE and will enable us to better interpret isotope anomalies in the geochemical record.
Large hemispheric difference in ultrafine aerosol concentrations in the lowermost stratosphere
Authors: Williamson Christina J , Kupc Agnieszka , Rollins Andrew , Kazil Jan , Froyd Karl D , Ray Eric A , Murphy Daniel M , Schill Gregory P , Peischl Jeff , Thompson Chelsea , Bourgeois Ilann , Ryerson Thomas , Diskin Glenn S , DiGangi Joshua P , Blake Donald R , Bui ThaoPau V , Dollner Maximilian , Weinzierl Bernadett , Brock Charles A
Published: March 2021

On the NASA Atmospheric Tomography Mission (ATom), we observed a sharp hemispheric contrast in the concentration of ultrafine aerosols (3-12 nm diameter) in the lowermost stratosphere that persisted through all four seasons. Exploring possible causes, we show that this is likely caused by aircraft, which emit both ultrafine aerosol and precursor gases for new particle formation (NPF) in quantities that agree well with our observations. While aircraft may emit a range of NPF precursors, we focus here on sulphur dioxide (a major source of atmospheric sulphuric acid), of which we have observations from the same mission.  We observe the same hemispheric contrast in sulphur dioxide as ultrafine aerosol, and find that the observed concentrations are in alignment with inventoried aircraft emissions. We present box modeling and thermodynamic calculations that support the plausibility of NPF under the conditions and sulphur dioxide concentrations observed on ATom.

While the direct climate impact of ultrafine aerosol in the lowermost stratosphere (LMS) may currently be small, our observations show a definitive size distribution shift of the background aerosol distribution in the northern hemisphere. This is important for assessing aviation impacts, and the expected impacts of increased air-traffic. Furthermore, climate intervention via injection of sulphate or aerosols into the stratosphere is a current subject of research. Our study shows that NPF is possible and likely already happening in the LMS, which must be accounted for in models for stratospheric modification, and points out that we must consider that any intentional stratospheric modification will be applied to two very different hemispheres: a largely pristine southern hemisphere; and an already anthropogenically modified northern hemisphere.
A smaller glacial ocean carbon inventory?
Authors: Shao Jun , Stott Lowell , Ridgwell Andy , Zhao Ning , Adolphi Florian , Yu Jimin
Published: March 2021

Previous studies attempting to explain Pleistocene atmospheric CO2 variations have focused on mechanisms that transfer carbon (C) between the oceanic, atmospheric and terrestrial reservoirs, with the underlying assumption that the total C inventory in these three Earth’s surface reservoirs remained constant during glacial-interglacial cycles. Under this framework, ocean C inventory would have been marginally increased by 500-1000 GtC (1-2%) during the glacial period. Here, we show that past ocean C inventory can be revealed by reconstructed bulk ocean 14C/12C (denoted as ∆14C) and atmospheric 14C production rates with an Earth system model - cGENIE. First, we develop a bulk ocean ∆14C record that spans the last 40 ka from thousands of benthic foraminifera and deep sea coral ∆14C data with a fairly good coverage of the global seafloor. We then run cGENIE under constant pre-industrial boundary conditions, with the only forcing being atmospheric 14C production rates reconstructed by geomagnetic field intensity records and ice core record of 10Be fluxes. Under most of the 14C production scenarios, the simulated bulk ocean ∆14C are significantly lower than our composite during the Last Glacial Maximum as well as the early deglaciation. Bulk ocean ∆14C is a metric controlled by 14C production rates and ocean C inventory, with the state of ocean circulation playing a minor role.  Our finding suggests either glacial 14C production was much higher and/or glacial C inventory was much lower than previously thought. Implications of both possibilities are discussed. In particular, the second possibility highlight the exchange of C and ALK between Earth’s surface and geological reservoirs as a critical missing piece in searching for a complete theory of glacial-interglacial atmospheric CO2 variability.
In-plane and out-of-plane shear fracture toughness of rocks
Authors: Bahrami Bahador , Nejati Morteza , Ayatollahi Majid Reza , Dreisner Thomas
Published: March 2021

Rocks in the subsurface are exposed to high amount of confinement which can potentially suppress the formation or the development of tensile-based cracks and thus, give rise to shear-based fracture growth. However, measuring the shear fracture toughness of rocks have been studied less in the literature, as providing the required confinement to force the shear fracturing precede tensile fracturing is not an easy task. In the current study, two new tests namely the double-edge notched Brazilian disk (DNBD) and the axially double-edge notched Brazilian disk (ANBD) are proposed to measure the in-plane (true mode II) and the out-of-plane (true mode III) shear fracture toughness of rocks, KIIc and KIIIc, respectively. We use the term true to emphasis that not only sustains the crack shear loading, but also the type of fracturing is shear-based. Finite element method is used to study the variations of stress field around the crack tip in these tests and to prove the applicability of the tests in providing mode II and mode III loading conditions. It is argued that both tests are straightforward and have several advantages compared to the existing ones. The effectiveness of the tests is empirically corroborated by conducting some experiments on Bedretto Granite. The pulverized surface of fracture in both the tests denotes the existence of friction which indicate the shear-based nature of fracture. Finally, the measured values of KIIc and KIIIc for Bedretto granite are compared to each other and to the reported values of KIc in the literature. It is shown that KIIc and KIIIc values are close to each other while both are more than two times greater than KIc.