bluuebunny/crossref_metadata_2025 huggingface dataset:
Incorrect Asian aerosols affecting the attribution and projection of regional climate change in CMIP6 models 
Authors: Lin Lei , Wang Zhili , Xu Yangyang , Che Huizheng , Zhang Xiaoye , Zhang Hua , Dong Wenjie , Wang Chense , Gui Ke , Xie Bing
Published: March 2021

Anthropogenic aerosol (AA) forcing has been shown as a critical driver of climate change over Asia since the mid-20th century. Here we show that almost all Coupled Model Intercomparison Project Phase 6 (CMIP6) models fail to capture the observed dipole pattern of aerosol optical depth (AOD) trends over Asia during 2006–2014, last decade of CMIP6 historical simulation, due to an opposite trend over eastern China compared with observations. The incorrect AOD trend over China is attributed to problematic AA emissions adopted by CMIP6. There are obvious differences in simulated regional aerosol radiative forcing and temperature responses over Asia when using two different emissions inventories (one adopted by CMIP6; the other from Peking university, a more trustworthy inventory) to driving a global aerosol-climate model separately. We further show that some widely adopted CMIP6 pathways (after 2015) also significantly underestimate the more recent decline in AA emissions over China. These flaws may bring about errors to the CMIP6-based regional climate attribution over Asia for the last two decades and projection for the next few decades, previously anticipated to inform a wide range of impact analysis.
Preliminary results of  South American infrasound monitoring
Authors: Neri Brandow , Barros Lucas
Published: March 2021

Infrasound monitoring is one of the four technologies used by the International Monitoring System to verify compliance with the CTBT. Atmospheric and shallow underground nuclear explosions can generate infrasound waves that can be detected by the infrasound networks. Of the 60 infrasonic stations proposed by CTBT, 10 are located in South American countries and islands close to the continent. Because the latest nuclear tests were underground and on the Asian continent, the infrasound stations in South America did not detect them. However, there are several sources of infrasound signals detect by South American stations. This work aims to present a complete catalog of infrasound events detected in South America.
No signal of a plume push force in Indo-Atlantic plate speeds before, during, or after Deccan plume arrival
Authors: Eagles Graeme , Pérez Díaz Lucía , Sigloch Karin
Published: March 2021

Observations of the apparent links between plate speeds and the global distribution of plate boundary types have led to the suggestion that subduction may provide the largest component in the balance of torques maintaining plate motions. This would imply that plate speeds should not exceed the sinking rates of slabs into the upper mantle. Instances of this ‘speed limit’ having been broken may thus hint at the existence of driving mechanisms additional to those resulting from plate boundary forces. The arrival and emplacement of the Deccan-Réunion mantle plume beneath the Indian-African plate boundary in the 67-62 Ma period has been discussed in terms of one such additional driving mechanism, leading to the establishment of “plume-push” hypothesis, which in recent years has gained significant traction. We challenge the model-based observations that form the principal evidence in favour of plume-push: a late Cretaceous pulse of anticorrelating accelerations and decelerations in seafloor spreading rates around the African and Indian plates. Using existing and newly-calculated high-resolution models of plate motion, we instead document an increase in divergence rates at 67-64 Ma. Because of its ubiquity, we consider this increase to be the artefact of a timescale error affecting chrons 29-28. Corrected for this artefact, the evolution of plate speeds resembles a smooth continuation of pre-existing late Cretaceous trends, consistent with the idea that the arrival of the Réunion plume did not substantially affect the existing balance of plate boundary forces on the Indian and African plates. 
Evolution of the climate in the next million years: A reduced-complexity model for glacial cycles and impact of fossil fuel CO2
Authors: Talento Stefanie , Ganopolski Andrey
Published: March 2021

We propose a reduced-complexity process-based model for the long-term evolution of the global ice volume, atmospheric CO2 concentration and global mean temperature. The model only external forcings are the orbital forcing and anthropogenic CO2 cumulative emissions. The model consists of a system of three coupled non-linear differential equations, representing physical mechanisms relevant for the evolution of the climate – ice sheets – Carbon cycle system in timescales longer than thousands of years. The model is successful in reproducing the glacial-interglacial fluctuations of the last 800 kyr, in good agreement with paleorecords both in terms of timing and amplitude, with a correlation between modelled and paleo global ice volume of up to 0.86.

Using different model realisations, we generate a probabilistic forecast of the evolution of the Earth system over the next 1 million years under natural and several fossil-fuel CO2 release scenarios. In the natural scenario, the model assigns high probability of occurrence of long interglacials in the periods between present and 50 kyr after present, and between 400 kyr and 500 kyr after present. The next full glacial conditions are most likely to occur 90 kyr after present. The model shows that even already achieved cumulative CO2 anthropogenic emissions (500 PgC) are capable of affecting the climate evolution for up to half million years, indicating that the beginning of the next glaciation is highly unlikely in the next 150 kyr. If cumulative fossil-fuel CO2 emissions reach 3000 PgC, or higher, the model predicts with high probability ice-free Northern Hemisphere landmass conditions will prevail in the next half million years, postponing the natural occurrence of the next glacial inception to 600 kyr after present.
Analysis of the active length dynamics on intermittent streams using water presence sensors
Authors: Zanetti Francesca , Durighetto Nicola , Vingiani Filippo , Botter Gianluca
Published: March 2021

Headwater streams are important for their hydrological function and for their significant contribution to the riverine ecosystems. Nevertheless their study has always been challenging because of the ephemeral and intermittent nature of those streams. Maps representing the active part of the river network are usually drawn after field surveys performed under different hydrologic conditions, which enable an objective evaluation of the temporal changes in the length of the active network. This method is useful to describe seasonal variations of the stream length, but has significant limitations when it comes to the description of event-based changes of the flowing network, provided that visual inspections of entire catchments are highly time-consuming. In this work, electrical resistance (ER) sensors were used to analyze event-based active network dynamics along some of the tributaries of an Alpine creek in northern Italy. Current intensity values were collected every 5 minutes by the sensors and a threshold electrical signal was identified to distinguish between wet and dry status of the reaches where the probes were placed. A statistical analysis revealed a good correlation among the mean current intensity recorded, the exceedance probability of the threshold and the persistency of the nodes. Data collected by the sensors were also interpolated in space along the network to obtain a sequence of maps of the active and dry parts of the stream network. From each map the wet length (L) of the watercourse was derived and linked to the corresponding discharge (Q) at the outlet of the catchment. Small and intense precipitation events had different effects on the variations of Q and L: the network length was found to be more sensitive than discharge to small precipitation inputs; relevant stream flow variations were instead observed only during significant events that originated the largest changes in the active network length.  This heterogeneous behaviour negatively affected the quality of the fitting of empirical discharges vs. wet length data through a power law model. Water presence sensors provide an opportunity to study in depth the spatiotemporal dynamics of the active length of intermittent streams and link such dynamics to the relevant hydrological drivers.
Using an interdisciplinary MOOC to teach climate science and science communication to a global classroom
Authors: Winkler Bärbel , Cook John
Published: March 2021

MOOCs (Massive Open Online Courses) are a powerful educational tool, making scientific content available to a large and diverse audience. The MOOC “Making Sense of Climate Science Denial” applies science communication principles derived from cognitive psychology and misconception-based learning in the design of video lectures covering many aspects of climate change. As well as teaching fundamental climate science, the course also presents psychological and critical thinking research into climate science denial, teaching students the most effective techniques for responding to misinformation. A number of the enrolled “students" have been secondary and tertiary educators, who have adopted the course content in their own classes as well as adapted their teaching techniques based on the science communication principles presented in the lectures. The MOOC—developed by John Cook while at the University of Queensland's Global Change Insitute—integrates cognitive psychology, educational research and climate science in an interdisciplinary online course that has had over 40,000 enrolments from over 180 countries since the MOOC was launched in 2015.
Rediscovery of a major alpine thrust : the Helvetic Basal Decollement
Authors: Mercier Antoine , Leloup Philippe Hervé , Courrioux Gabriel , Caritg Séverine , Lopez Simon , Kalifi Amir
Published: March 2021

Since two centuries the European Alps are a natural laboratory to study continental lithosphere deformation during mountain building. Since the early studies, a constant question has been to evaluate the importance of vertical versus horizontal displacements in the building of reliefs. Whilst the occurrence of large thrust sheets, as initially proposed from field observations, are now well explained in the frame of plate tectonics, controversies still arise on the precise geometry, amount, and timing of major thrusting during the orogeny.

We present a new detailed 3D structural study of the cover/basement relationships in the Chamonix synclinorium in between the Mont-Blanc (MB) and Aiguilles Rouges (AR) ranges. These massifs are two of the main external basement ranges of the western Alps.  The study allows deciphering the area structural history: the Mesozoic sedimentary cover has been thrust at least 10km NW above the Helvetic Basal Décollement (HBD) before to be offset by late steep thrusts during exhumation in the Miocene.

Such interpretation fundamentally diverges from the classical view of the sedimentary cover of the Chamonix synclinorium being expulsed from a former graben during a single deformation phase and implies that a major thrust phase lasting ~10 Ma has been overlooked. Our observations show that the HBD was a major thrust system active between ~30 and ~20 Ma, possibly until 15 Ma, with a shortening of more than 10km in the south to 20km in the north. It extends below most of the subalpine ranges and emerges in front of the Bauges and within the Chartreuse and Vercors massifs, and was rooted east of the External Cristalline Massifs (Mont-Blanc and Belledonne). During the Miocene, the HBD was cut by steep reverse faults and uplifted above the basement culmination of the External Cristalline Massifs obscuring its continuity and precluding its recognition as a major structure even if it was previously described at several localities.
Slow-slip, earthquake-swarms and fault-interactions at the western-end of the Hellenic Subduction System precede the Mw 6.9 Zakynthos Earthquake, Greece 
Authors: Mouslopoulou Vasiliki , Bocchini Gian Maria , Cesca Simone , Saltogianni Vasso , Bedford Jonathan , Petersen Gesa , Gianniou Michael , Oncken Onno
Published: March 2021

The month-to-year-long deformation of the Earth’s crust where active subduction zones terminate is poorly explored. Here we report on a multidisciplinary dataset that captures the synergy of slow-slip events, earthquake swarms and fault-interactions during the ~5 years leading up to the 2018 Mw 6.9 Zakynthos Earthquake at the western termination of the Hellenic Subduction System (HSS). It appears that this long-lasting preparatory phase initiated due to a slow-slip event that lasted ~4 months and released strain equivalent to a ~Mw 6.3 earthquake. We propose that the slow-slip event, which is the first to be reported in the HSS, tectonically destabilised the upper 20-40 km of the crust, producing alternating phases of seismic and aseismic deformation, including intense microseismicity (M<4) on neighbouring faults, earthquake swarms in the epicentral area of the Mw 6.9 earthquake ~1.5 years before the main event, another episode of slow-slip immediately preceding the mainshock and, eventually, the large (Mw 6.9) Zakynthos Earthquake. Tectonic instability in the area is evidenced by a prolonged (~4 years) period of overall suppressed b-values (<1) and strong earthquake interactions on discrete strike-slip, thrust and normal faults. We propose that composite faulting patterns accompanied by alternating (seismic/aseismic) deformation styles may characterise multi-fault subduction-termination zones and may operate over a range of timescales (from individual earthquakes to millions of years).
Do active faults’ clay mineral compositions affect whether earthquake ruptures they host will displace the surface?
Authors: Fenske Selina S. , Toy Virginia G. , Schuck Bernhard , Schleicher Anja M. , Reicherter Klaus
Published: March 2021

The tectonophysical paradigm that earthquake ruptures should not start, or easily propagate into, the shallowest few kilometers of Earth’s crust makes it difficult to understand why damaging surface displacements have occurred during historic events. The paradigm is supported by decades of analyses demonstrating that near the surface, most major fault zones are composed of clay minerals – particularly extraordinarily weak smectites – which most laboratory physical measurements suggest should prevent surface rupture if present. Recent studies of New Zealand’s Alpine Fault Zone (AFZ) demonstrate smectites are absent from some near surface fault outcrops, which may explain why this fault was able to offset the surface locally in past events. The absence of smectites in places within the AFZ can be attributed to locally exceptionally high geothermal gradients related to circulation of meteoric (surface-derived) water into the fault zone, driven by significant topographic gradients. The record of surface rupture of the AFZ is heterogeneous, and no one has yet systematically examined the distribution of segments devoid of evidence for recent displacement. There are significant implications for seismic hazard, which comprises both surface displacements and ground shaking with intensity related to the area of fault plane that ruptures (which will be reduced if ruptures do not reach the surface).  We will present results of new rigorous XRD clay mineral analyses of AFZ principal slip zone gouges that indicate where smectites are present, and consider if these display systematic relationships to surface displacement records. We also plan to apply the same methodology to the Carboneras Fault Zone in Spain, and the infrequent Holocene-active faults in Western Germany.
A conceptual framework of drought legacies in grasslands
Authors: Müller Lena M. , Bahn Michael
Published: March 2021

As a consequence of climate change, extreme climatic events such as droughts will become more frequent and severe, affecting ecosystem structure and functioning, with implications for humans and society. While concurrent effects of drought events are comparatively well studied, the short- and longer-term changes in ecosystem structure and functioning triggered by drought (i.e. drought legacies) are far less understood. Furthermore, it has rarely been analysed how drought legacies alter the resistance to and recovery from subsequent drought events. To assess the overall impact of drought events on ecosystems and emerging cascading effects on societies, we need to advance the understanding of drought legacies and their long-lasting impacts on ecosystems. Based on a review of the literature on above- and belowground mechanisms underlying drought legacies in grasslands, we propose a conceptual framework, which identifies the factors determining the shape of potential legacy trajectories during recovery and post-recovery phases and synthesize the mechanisms leading to legacy responses to subsequent drought events.
Enzymatic and microbial activities as influenced by tillage and fertilization in a semi-arid Mediterranean agroecosystem
Authors: De Mastro Francesco , Traversa Andreina , Brunetti Gennaro , Blagodatskaya Evgenia
Published: March 2021

Soil enzymes respond rapidly to changes in soil managements, and therefore are used as early and sensitive indicators of alteration in soil properties induced by tillage and additions of fertilizers. The aim of this work was to compare the effects of different tillage (no, minimum, and conventional tillage), fertilization and soil depth (0-30, 30-60 and 60- 90 cm) on the microbial biomass, enzyme activity and their relationship with soil nutrients in a semiarid Mediterranean agro-ecosystem. Growing and total microbial biomass decreased with depth together with the activities of β-glucosidase and N-acetyl-β-glucosaminidase presumably because of the reduced carbon and oxygen content in the deeper layers of soils. The fertilization stimulated fast-growing microorganisms with low affinity of enzyme systems to substrate, enhanced the growing microbial biomass and facilitated the turnover rate of soil organics. Under no tillage, all enzymes showed higher potential activity in top layers of fertilized plots as compared with non-fertilized ones. The minimum tillage practice increased the growing microbial biomass, and stimulated N- and P-acquiring enzymes due to  increased nutrients limitation. Parameters of microbial growth and enzyme kinetics are suitable indicators of microbial activity in semiarid Mediterranean agroecosystems.
Maritime built heritage and marine wildlife: Remote sensing as a tool to identify and prioritise integrated conservation in coastal environments
Authors: Baxter Tim , Coombes Martin , Viles Heather
Published: March 2021

Maritime built heritage is threatened by natural hazards and human activities around the world. Likewise, marine wildlife is increasingly threatened by the effects of climate change and human development. Due to their age and traditional construction, maritime built heritage (e.g. historic harbours) may provide unique habitats for diverse assemblages of marine wildlife. Yet, as aspects of built heritage are often missing in assessments of marine infrastructure, identifying which heritage assets have the potential to provide the greatest ecological benefits remains a challenge. An improved understanding of the ecological importance of maritime built heritage can enhance arguments for its continued protection, maintenance and repair. At the same time, this may present new opportunities to conserve important and largely unidentified hotspots of marine biodiversity.

Using preliminary results from the Isles of Scilly, UK, this study presents a novel method for quantifying the full extent of marine engineering structures (including heritage assets) at a regional scale, and for identifying priority structures for joint biodiversity and heritage conservation.

Remote sensing data were considered alongside historic environment data and records of modern coastal defences in a rapid desk-based assessment to create a complete inventory of marine structures along the entire coastline of the Isles of Scilly. In total, 68 structures were recorded (6,180 m in length), with over half registered as heritage assets. LiDAR and aerial photography were used to determine the site characteristics of each structure (e.g. shore position). This allowed for an initial assessment of the potential ecological importance of these structures when considered alongside structural information, including building age and material. By evaluating the ecological potential and heritage value of each structure using a novel scoring system, priorities for conservation and other managed interventions are identified. This includes listed buildings and scheduled monuments that due to their construction features and shore position are most likely to support diverse marine assemblages.

Combined ecological-heritage evaluations incorporating remote sensing datasets allow for the identification of those structures with the greatest potential for the integrated conservation of built heritage and marine wildlife. Research is now needed to develop this method further, ground-truth its outputs, and test its application in other geographical locations and at varying scales.
Tree segmentation and classification of deciduous park trees in Sanssouci Park, Potsdam, Germany, using airborne and terrestrial lidar point clouds
Authors: Rheinwalt Aljoscha , Bookhagen Bodo
Published: March 2021

While automated, lidar-based tree delineation has proven successful for
conifer-dominated forests, deciduous tree stands remain a challenge.  But
automatic and reliable segmentation of trees at large spatial scales is a
prerequisite for a supervised classification into tree species. We propose an
aspect driven tree segmentation that clusters local elevation minima across
different aspects. These clusters define tree outlines that respect tree
inherent local elevation minima. We validate this approach with more than
25.000 mapped trees of the Sanssouci Park, Potsdam, using an airborne lidar
point cloud collected in 2018, and various terrestrial lidar scans for a large
fraction of the same park. Further, we demonstrate the tree segmentation by
supervised tree species classifications for the most common tree species using
random forests and Gaussian process classifiers with geometric parameters
derived from individual tree crowns.
Atmospheric Correction Inter-comparison eXercise: the second implementation 
Authors: Doxani Georgia , Vermote Eric F. , Skakun Sergii , Gascon Ferran , Roger Jean-Claude
Published: March 2021

The atmospheric correction inter-comparison exercise (ACIX) is an international initiative to benchmark various state-of-the-art atmospheric correction (AC) processors. The first inter-comparison exercise initiated in 2016 with the collaboration of European Space Agency (ESA) and National Aeronautics and Space Administration (NASA) in the frame of the CEOS WGCV (Committee on Earth Observation Satellites, Working Group on Calibration & Validation). The evolution of the participating processors and the increasing interest of AC community to repeat and improve such experiment stimulated the continuation of ACIX and its second implementation (ACIX-II). In particular, 12 AC developer teams from Europe and USA participated in ACIX-II over land sites. In this presentation the benchmarking protocol, i.e. test sites, input data, inter-comparison metrics, etc. will be briefly described and some representative results of ACIX-II will be presented. The inter-comparison outputs varied depending on the sensors, products and sites, demonstrating the strengths and weaknesses of the corresponding processors. In continuation of ACIX-I achievements, the outcomes of the second one are expected to provide an enhanced standardised approach to inter-compare AC processing products, i.e. Aerosol Optical Thickness (AOT), Water Vapour (WV) and Surface Reflectance (SR), and quantitively assessed their quality when in situ measurements are available.
Water wave resonance in a circular oscillating channel
Authors: Borcia Ion Dan , Richter Sebastian , Xu Wenchao , Borcia Rodica , Harlander Uwe , Bestehorn Michael
Published: March 2021

Nonlinear surface waves in the form of tidal bores can have a profound impact on the flow in rivers and estauries. The waves can also be studied experimentally in a specially designed periodic channel at BTU Cottbus-Senftenberg [1],[2]. We hence analyze these surface waves in this narrow circular channel partially filled with water and compare the data with numerical simulations. The flow in the channel is blocked by a barrier and the channel oscillates in azimuthal direction with variable frequency,  maintaining the same maximum velocity. The response in terms of wave shape, maximum amplitude and root mean square of the surface deviations are numerically investigated and compared with experiments. Note that for the experimental setup a number of maximum eight ultrasound sensors can provide the local height evolution. Due to the oscillations, the barrier produces wave trains or hydraulic jumps which then propagate inside the channel. Reflections, damping and collisions take place. Some frequencies are  favourised and in the first approximation can also be calculated using a shallow water model. How will be seen, only the odd multiples of the basic frequency produce high answers (resonances).

[1] I.D. Borcia, R. Borcia, Wenchao Xu, M. Bestehorn, S. Richter, and U. Harlander. Undular bores in a large circular channel. European Journal of Mechanics - B/Fluids, 79, 67-73, 2020.

[2] I.D. Borcia, R. Borcia, S. Richter, Wenchao Xu, M. Bestehorn, and U. Harlander. Horizontal Faraday instability in a circular channel. Proceedings in Applied Mathematics and Mechanics (PAMM), 19, , 2019.
Trade-offs between deep (magmatic) and shallow (hydrological) forcings on volcanic unrest at La Soufrière de Guadeloupe (Lesser Antilles)
Authors: Jessop David , Moretti Roberto , Moune Séverine , Robert Vincent
Published: March 2021

Fumarolic gas composition and temperature record deep processes that generate and transfer heat and mass towards the surface.  These processes are a result of the emplacement, degassing and cooling of magma and the overturning of the above hydrothermal system.  A reasonable expectation, and too often an unproved assumption, is that fumarole temperatures and the deep heat sources vary on similar timescales.  Yet signals from deep and shallow processes have vastly different temporal variations.  This indicates that signals arising from deep activity may be masked or modified by intervening hydrothermal processes, such as fluid-groundrock reactions in which secondary minerals play a major role.  Clearly, this complicates the interpretation of the signals such as the joint variation of fumarole vent temperature and geochemical ratios in terms of what is occurring at depth.  So what do the differences between the timescales governing deep and shallow processes tell us about the intervening transport mechanisms?

At the volcanic dome of La Soufrière de Guadeloupe, the Observatoire Volcanologique et Sismologique de la Guadeloupe has performed weekly-to-monthly in-situ vent gas sampling over many years.  These analyses reliably track several geochemical species ratios over time, which provide important information about the evolution of deep processes.  Vent temperature is measured as part of the in-situ sampling, giving a long time series of these measurements.  Here, we look to exploit the temporal variations in these data to establish the common processes, and also to determine why these signals differ.  By fitting sinusoids to the gas-ratio time series we find that several of the deep signals are strongly sinusoidal.  For example, the He/CH4 and CO2/CH4 ratios, which involve conservative components and mark the injection of deep and hot magmatic fluids, oscillate on a timescale close to 3 years. We also analyse the frequency content of the temperature measurements since 2011 and find that such long signals are not seen.  This may be due to internal buffering by the hydrothermal system, but other external forcings are also present.  From these data we build up a more informed model of the heat-and-mass supply chain from depth to the surface.  This will potentially allow us to predict future unrest (e.g. thermal crises, seismic swarms), and distinguish between sources of unrest.
Exploring geothermal resources using active and passive EM methods in the coastal areas of volcanic islands
Authors: Védrine Simon , Tarits Pascal , Darnet Mathieu , Bretaudeau François , Hautot Sophie
Published: March 2021

Electromagnetic geophysical exploration plays a key role in high-temperature geothermal projects to estimate the geothermal potential of a region. The objective of an EM campaign applied to high-temperature geothermal exploration is to obtain an image of the impermeable clay cap, the permeable geothermal reservoir, and the system's heat source at depth, as these three components of the overall geothermal system have distinct electrical signatures. However, deep electromagnetic imaging in the coastal areas of volcanic islands represents a major challenge due to the presence of strong cultural noise induced by urbanized areas concentrated around the coast, the proximity to the sea, strong variations of topography and bathymetry, the small size of targets and the heterogeneity of the near surface. Our objective is the multi-scale integration of airborne transient electromagnetism (ATEM), shallow marine and in land magnetotelluric (MT) and controlled source electromagnetism (CSEM) to improve the reconstruction of deep geological structures by inversion. The contribution of the CSEM method is the key to overcoming cultural electromagnetic noise and exploiting data acquired in urbanized areas. In order to study how to integrate the different EM data, we first apply our methodology to data from a geothermal exploration campaign carried out a few years ago in Martinique in the French West Indies. Then, we present results from runs with synthetic tests for a campaign planned this year in Guadeloupe, also in the French West Indie, whose objective is to increase the production capacity of an existing geothermal field.
Mechanisms of heat storage and trend in the Mediterranean Sea in a high emission CMIP6 scenario with the regional climate system model CNRM-RCSM6.
Authors: Sevault Florence , Waldman Robin , Somot Samuel , Nabat Pierre
Published: March 2021

The Earth’s climate is regulated by the ocean, which absorbs, transports and releases heat through continuous exchanges with the atmosphere. In regional climate modelling, an increasing consensus has emerged on the added value of ocean-atmosphere coupled systems to allow for these exchanges, through interactive and realistic air-sea interactions. This coupling is controlled by the Sea Surface Temperature (SST), itself regulated by the capacity for the ocean component to store heat at depth.

We address here the question of heat storage and trend in the different depths of the Mediterranean Sea in a CMIP6 historical and SSP5-8.5 scenario with the Regional Climate System Model CNRM-RCSM6 driven by CNRM-ESM2-1 simulation. CNRM-RCSM6 is composed by ALADIN-Climate at a 12 km resolution for the atmosphere, with the interactive aerosol scheme TACTIC and the multi-surface model SURFEX v8, CTRIP at a 50 km resolution for the river routing with deep drainage, flood plains, and the lake parametrization FLAKE, NEMOMED12 at a 6 km resolution for the ocean, and OASIS3-MCT for a 1hr-coupling of the four models. The simulation begins in 1979 after 79 years of coupled spin-up, and a control simulation also exists.

We investigate the timing, location and magnitude of heat storage by the Mediterranean Sea. In particular, we assess the link between SST warming and vertical heat storage, and its possible seasonality. We illustrate the sensitivity of heat storage to salinity trends by comparing the western and eastern Mediterranean behaviours. Finally, we make use of an online heat trend diagnostic tool to characterize the dominant mechanisms of ocean heat storage in the Mediterranean Sea.
Reconstruction of vine hydraulic behaviour from tree-ring series up to must in Falanghina under different pedo-climatic conditions 
Authors: Damiano Nicola , Battipaglia Giovanna , Cirillo Chiara , Erbaggio Arturo , Cherubini Paolo , Bonfante Antonello , De Micco Veronica
Published: March 2021

In the Mediterranean region, climate-change-driven increasing temperature and frequency of prolonged drought periods are affecting physiological behaviour and vine growth, with consequences on berry yield and quality. Assessing how plants have reacted to past environmental fluctuations can help understanding current plant behaviour and forecast possible responses to climate changes. The improvement of knowledge about the plasticity of morpho-functional traits in vines as response to climatic stress conditions can help the management of vineyards.

In this study, we applied a wood-sciences approach to reconstruct past vine hydraulic behaviour in four vineyards of Vitis vinifera L. subsp. vinifera ‘Falanghina’ located in southern Italy (La Guardiense farm, Benevento, Campania region), cultivated in different pedo-climatic conditions onto the same rootstock. Wood cores were extracted by the vine trunk and prepared for microscopy and stable isotope analyses to quantify functional wood anatomical traits and δ13C to assess plant water use efficiency.

Vineyard performances were also monitored in vivo at the main phenological phases (flowering, fruit set, veraison, ripening), through the analysis of morphological, eco-physiological and production parameters. Stable isotopes were also traced in leaves and must. Soil profiles were characterised at the four sites that were also monitored for main climatic factors.

All parameters linked with vine hydraulics, resource use and growth efficiency showed a site-specific precise coordination linked with different water and resource availability as influenced by pedo-climatic conditions. The different vines hydraulic behaviour at the four sites, derived from the analysis of the tree-ring series and confirmed by in vivo plant monitoring, contributed to different vines productivity and quality of musts. The isotopic signal of wood and must showed a similar trend, suggesting that they both record the same ecophysiological information. These innovative results suggest the possibility to use must as a good matrix to perform carbon isotope analysis and derive information on plant water use in response to pedo-climatic factors.

The overall information gained through the proposed methodological approach seem to be promising to better understand plant-environment relations in the continuum soil/plant/atmosphere, useful for the management of vineyard to achieve a more sustainable wine production.
Wildfire extreme events: Large-scale developments in fire activity of New South Wales, Australia
Authors: Nolde Michael , Mueller Norman , Strunz Günter , Fichtner Florian , Plank Simon , Riedlinger Torsten
Published: March 2021

Disastrous wildfires have occurred in many parts of the world during the last two years (2019 and 2020), most notably in South America, Australia, the United States, and regions north of the polar circle. Such extreme wildfire events pose a pervasive threat to human lives and property and have thus been widely recognized in the global media. This study focusses on large-scale developments in fire activity. It investigates the occurrence of burnt areas regarding several relevant parameters, namely fire extent, fire severity and fire seasonality. The entirety of those parameters allows an extensive insight regarding large-scale, long-term fire activity trends.

The burnt area derivation process, which is fully automated, is described in the literature (see reference below). The analysis is based on an extensive set of satellite data, specifically 9,612 granules of the MODIS MOD09/MYD09 product in conjunction with 3,503 tiles of the OLCI (Ocean and Land Colour Instrument) instrument onboard Sentinel-3.

The study design consists of two parts:

Firstly, the long-term temporal variability in fire activity, covering the time span from 2000 until 2020, is analyzed for the study region of New South Wales, Australia.

Secondly, the large-scale spatial variability is investigated by comparing the New South Wales extreme events in 2019/2020 with events of comparable magnitude in California, US and the Siberian taiga.

The study shows that New South Wales features an upward trend regarding the extent of yearly affected area, as well as a shift towards a prolongated end of the fire season towards the Autumn months. It also shows the exceptionality of the Australian wildfire activity in comparison with other geographical regions.

 

Reference:

Nolde, Michael; Plank, Simon; Riedlinger, Torsten. "An Adaptive and Extensible System for Satellite-Based, Large Scale Burnt Area Monitoring in Near-Real Time." Remote Sensing 12.13 (2020): 2162.
Noise correction and integration of HR-GNSS and seismological data for small earthquakes
Authors: Kudłacik Iwona , Kapłon Jan
Published: March 2021

High-rate GNSS (HR-GNSS) observations are used for high-precision applications, where the point position changes in short intervals are required, such as earthquake analysis or structural health monitoring. We aim to apply the HR-GNSS observations into mining tremors monitoring, where the dynamic displacement amplitudes reach maximally dozens of millimetres. The study contains the analysis of several mining tremors of magnitudes 3-4 in Poland, recorded within the EPOS-PL project.

The HR-GNSS position is obtained with over 1 Hz frequency in kinematic mode with relative or absolute approaches. For short periods (up to several minutes), the positioning accuracy is very high, but the displacement time series suffer from low-frequency fluctuations. Therefore, it is not possible to apply them directly in the analysis of seismic phenomena, thus it is necessary to filter out low- and high-frequency noise.

In this study, we discussed some methods that are useful to reduce the noise in HR-GNSS displacement time series to obtain precise and physically correct results with reference to seismological observations, which for dynamic position changes are an order of magnitude more accurate. We presented the band-pass filtering application with automatic filtration limits based on occupied bandwidth detection and the discrete wavelet transform application with multiresolution analysis. The correction of noise increases the correlation coefficient by over 40%, reaching values over 0.8. Moreover, we tested the application of the basic Kalman filter to the integration of sensors: HR-GNSS and an accelerometer to visualize the most actual displacements of the station during a small earthquake - a mining tremor. The usefulness of this algorithm for the assumed purpose was confirmed. This algorithm allows to reduce the noise from HR-GNSS results, and on the other hand, to minimize the potential seismograph drift and its errors caused by the limited dynamic range of the seismograph. An unquestionable advantage is the possibility of obtaining a time series of displacements with a high frequency (equal to the frequency of seismograph observations, e.g. 250 Hz) showing the full range of station motion: dynamic and static displacements caused by an earthquake.
Intraseasonal to decadal variability of Rossby wave packet properties
Authors: Fragkoulidis Georgios , Wirth Volkmar
Published: March 2021

The large-scale extratropical upper-tropospheric flow tends to organize itself into eastward-propagating Rossby wave packets (RWPs). Investigating the spatiotemporal evolution of RWPs and the underlying physical processes has been beneficial in showcasing the role of the upper-tropospheric flow in temperature and precipitation extremes. The use of recently developed diagnostics of local in space and time wave properties has provided further insight in this regard. Motivated by the above, these diagnostic methods are now being employed to investigate the intraseasonal to decadal variability of key RWP properties such as their amplitude, phase speed, and group velocity in reanalysis datasets. It is shown that these properties exhibit a distinct seasonal and interregional variability, while interesting patterns thereof emerge. Moreover, the interannual and long-term variability in these RWP properties is explored and significant decadal trends for specific regions and seasons are highlighted. Ongoing work aims at further utilizing the presented diagnostics and analyses toward an improved understanding of the extratropical large-scale flow variability from weather to climate time scales.
The interaction between the Apula plate and the Calabrian Accretionary Wedge in the Northern Ionian Sea: tectonic-stratigraphic evolution and implications for subduction processes.
Authors: Chizzini Nicolò , Artoni Andrea , Torelli Luigi , Polonia Alina , Basso Jessica , Gasperini Luca
Published: March 2021

In the collisional setting of the Northern Ionian Sea, the Calabrian Accretionary Wedge, which represents the Southeastward prolongation of the Southern Apennines, is facing directly the subducting Apula plate, which is mainly made of Mesozoic to Tertiary Carbonate Platform. The aim of this contribution is to illuminate the structures and stratigraphic relationships between the frontal part of the orogenic belt, the foredeep and adjacent Apulian foreland. Because of the lack of exploration wells in these deep offshore basins, a detailed seismic facies analysis of six multichannel seismic profiles has been carried out to define the tectonic-sedimentary evolution of the study area.
Seismic interpretation allows to identify four main structural domains. The highly tectonized accretionary wedge is characterized by compressive tectonics. A narrow foredeep basin is filled by a thick (1,5–0,9 s TWT) Pliocene-Holocene subhorizontal succession and lies above buried normal faults. A massive carbonate succession of the Apulian Platform, shows reef and carbonate platform margin facies. A layered carbonate succession of the Apulian Platform is characterized by ‘'intra-platform'’ facies and located in the easternmost portion of the area. Seismic stratigraphic analysis allows to define two main regional unconformities with characteristic relationships with structural trends: i) the Messinian unconformity, related to a regional and significant erosion associated to paleokarst processes on the exposed Mesozoic Apulian Platform, is cut by an array of normal faults affecting the entire Apulian foreland and by reverse faults in the accretionary wedge; ii) the middle Pliocene Unconformity, an angular and erosive unconformity truncating the Lower Pliocene reflectors, is affected by normal faults in the foreland and by compressive tectonics in the Calabrian wedge that is progressively advancing.
Seismic data analyses shows that the compressive tectonics is currently active in the Calabrian Accretionary Wedge and concentrated in the innermost domains where thrust faults deform the sea floor. The Mesozoic Apulian Platform is affected by normal faulting driven by flexural bending since Lower Pliocene. The new structural map shows that transpressive and positive inversion tectonics is a common deformational style in the foreland that can be associated with the Dinaric-Hellenic subduction, which is synchronous with respect to Calabrian subduction. According to these observations, the compressive tectonics affecting the Apulia plate can be interpreted as related to both the Calabrian and Dinaric-Hellenic shortening processes. The interference of these two orogenic wedges with the Apulia Plate plays an important role in defining the tectonic evolution of the Northern Ionian Sea.
Classifying and mapping fuels in central European forests
Authors: Labenski Pia , Ewald Michael , Fassnacht Fabian Ewald
Published: March 2021

In recent years, forest fires have become more frequent in central Europe. As the frequency and magnitude of future extreme weather events such as droughts are projected to increase, also the trend of increasing fire frequency in temperate forests is expected to continue. However, knowledge about fire behavior and spread dynamics in these forests is scarce. One of the key drivers of fire behavior is the availability of flammable vegetation, i.e. fuels. In the project ErWiN, we aim to describe the amount and distribution of fuels in different forest types in Southwestern Germany. Detailed field inventories of fuels in all vertical strata of the stands allow a first classification into different fuel types, which can be used in fire behavior simulations to obtain estimates of fire spread and intensity. In a further step, deep learning algorithms will be trained on recognizing these fuel types on GNSS located photos of forest stand situations to provide an efficient solution for mapping fuels in the field. By coupling field data with detailed remotely sensed information on forest structure obtained from airborne laserscanning, continuous fuel maps will be derived. Such fuel maps in turn allow landscape-scale analysis of fire behavior and can be useful in forest management decisions as well as in developing firefighting strategies. We thus hope to make a contribution to a better understanding of fuel-driven fire risk in central European forests and to facilitate the operational use of fire behavior models. In this contribution we present the concept developed in the ErWiN project and present first results obtained from the field survey of fuel types in Southwestern Germany.
Using a novel combination of autonomous vehicles for air-sea interaction studies: Results from the Eurec4a campaign 
Authors: Siddle Elizabeth , Heywood Karen J. , Webber Ben , Bromley Peter
Published: March 2021

The Tropical North Atlantic region is a key driver of climate variability and extreme weather events, driven largely by heat and momentum exchanges across the air-sea boundary. Observations of these fluxes by satellites and vessels are limited in their spatial resolution and length of time series respectively. In-situ samples across long time periods are needed, which can be obtained through developing a network of in-situ flux measurement platforms. UEA and AutoNaut have worked to address this challenge with the deployment of Caravela - an AutoNaut uncrewed surface vessel. Caravela is a wave and solar powered autonomous vessel, equipped with meteorological and oceanographic sensors and the ability to transport a Seaglider. Caravela successfully completed its first scientific deployment as part of the Eurec4a campaign. 

Eurec4a ran from January—March 2020 from Barbados, investigating climate change feedback in the Tropical North Atlantic and the role of cloud systems. Caravela spent 11 days of her 33-day deployment occupying a 10 km square, co-located with other Eurec4a platforms to gather in-situ surface data on heat and momentum exchange. Preliminary results from Caravela give us an insight into heat exchange at the surface, downwelling radiation and wind conditions during deployment. There is an identifiable diurnal cycle during the deployment, particularly visible in temperature data, which will feed into our understanding of changes in fluxes at a local scale. Profiling ocean gliders at the study site allow us to determine a time series of upper ocean heat content changes. These data, alongside that collected by other platforms during Eurec4a, should enable an upper ocean heat budget to be calculated at Caravela’s study site. 