bluuebunny/crossref_metadata_2025 huggingface dataset:
Holocene reconstruction of plant and mammal communities in the Austrian and Italian Alps
Authors: Zetter Scarlett , Garces Pastor Sandra , Lammers Youri , Brown Antony Gavin , Tribsch Andreas , Coissac Eric , Lavergne Sebastien , Heintzman Peter D. , Alsos Inger G.
Published: March 2020

The Eastern Alps in Europe have a rich alpine biodiversity and a long archaeological history. However, the palaeoecological record of this region has been relatively understudied, which has limited our understanding of the formation of the contemporary vegetation since the end of the last Ice Age, including the likely impacts of changes in climate and human pressures through pasturing and agriculture. To fill this knowledge gap, we are using plant and mammal sedaDNA taken from five sub-alpine to alpine Holocene lake cores in the Austrian and Italian Eastern Alps: Grosser Winterleitensee, Krummschnabelsee, Mittlerer Kaltenbachsee and Sulzkarsee (Austria), and Laghetti Colbricon (Italy). We will outline our first results on full plant community reconstructions from some lakes and on the mammal presence. Findings from the plant record will allow us for uncovering the Holocene dynamics of plant communities, and for identifying key intervals where biodiversity may have been strongly affected by anthropogenic factors and climate change. The mammal sedaDNA data will also be used to track the presence of domestic livestock through time and therefore provide insight into past human pastoral practices in the region.
Evidence of recent activity in the Camorro Fault (Central Betics, Southern Spain)
Authors: Galve Jorge P. , Reyes-Carmona Cristina , Jabaloy Antonio , Ruano Patricia , Pérez-Peña José Vicente , Azañón José Miguel , Booth-Rea Guillermo
Published: March 2020

The Camorro Fault is located at the foot of the northern slope of a limestone karstic massif that is called ‘Sierra de Las Chimeneas’, in the central sector of the Betic Cordillera (Southern Spain). The fault shows a well-marked surface expression. It is a 6 km-length strike-slip with extensional component fault that forms part of the Torcal Shear Zone. This fault can be continued 7 km eastward along the foot of northern slope of the ‘Torcal de Antequera’ (Málaga), World Heritage Site since 2016. The Camorro fault plane is well-exposed in some sectors while in others, the fault plane has been either affected by karstification processes or partially covered by talus deposits.

One of the most characteristic geomorphological features of the ‘Sierra de Las Chimeneas’ area is an impressive rock avalanche deposit, covering an area of 2.2 km2 and for which we estimated a volume of 0.48 Hm3. Given the characteristics of the rock avalanche deposit, we consider that it could be triggered by an earthquake on the Camorro Fault. This hypothesis is supported by other investigations that have already referred to quaternary paleoseismicity in this area. Previous archaeological research revealed a period of human occupation in a cave (‘Cueva del Toro’) located in the ‘Torcal de Antequera’ that point out evidences about the occurrence of a cataclysm in the late Copper Age (about 5000 years ago). Other studies have also suggested a possible connection between seismic events and megalith-building near Antequera. Beyond this, an archaeoseismic analysis in the megalithic site of Antequera (also World Heritage Site since 2016) found deformation structures probably linked to oscillations between the megalith orthostats during an earthquake. According to all of mentioned research, the Camorro Fault could be a good candidate to account for such prehistoric earthquake.

Further geochronological work remains to be done, specially focused on dating (e.g. by cosmogenic isotopes) the fault scarp of the Camorro Fault and the associated rock avalanche deposits. If cosmogenic and archaeological dates coincide, we could attribute all the mentioned observations to an earthquake of severe magnitude in an area where the population ignore that hazard. Thus, we could contribute not only to the history of human occupation of the World Heritage Site but also providing insights into the earthquake recurrence and seismic hazard of the region.
Two ice shelf populations revealed in new gravity- derived bathymetry for the Thwaites, Crosson and Dotson ice shelves
Authors: Jordan Tom , Porter David , Tinto Kirsty , Millan Romain , Muto Atsuhiro , Hogan Kelly , Larter Robert , Graham Alastair , Paden John
Published: March 2020

Ice shelf buttressing plays a critical role in the long-term stability of ice sheets. The underlying bathymetry and cavity thickness therefore is a key to accurate models of future ice sheet evolution. However, direct observation of sub-ice shelf bathymetry is time consuming, logistically risky, and in some areas simply not possible, meaning there is a blind-spot in our understanding of this key system. Here we use airborne gravity anomaly data to provide new estimates of sub-ice shelf bathymetry outboard of the rapidly changing West Antarctic Thwaites Glacier, and beneath the adjacent Dotson and Crosson Ice Shelves. These regions are of especial interest as the low-lying inland reverse slope of the Thwaites glacier system makes it vulnerable to collapse through marine ice sheet instability, with rapid grounding-line retreat observed since 1993 suggesting this process may be underway. Our results confirm a major marine channel > 800 m deep extends to the front of Thwaites Glacier, while the adjacent ice shelves are underlain by more complex bathymetry. Comparison of our new bathymetry with ice shelf draft reveals that ice shelves formed since 1993 comprise a distinct population where the draft conforms closely to the underlying bathymetry, unlike the older ice shelves which show a more uniform depth of the ice base. This indicates that despite rapid basal melting in some areas, these “new” ice shelves are not yet in equilibrium with the underlying ocean system. We propose qualitative models of how this transient ice-shelf configuration may have developed, but further investigation is required to constrain the longevity and full impact of these newly recognised systems.
The dynamics of the inner boundary of the outer radiation belt during geomagnetic storms
Authors: Shi Xiaofei , Ren Jie , Zong Qiugang
Published: March 2020

We present a statistical study of energy-dependent and L shell-dependent inner boundary of the outer radiation belt during 37 isolated geomagnetic storms using observations from Van Allen Probes from 2013 to 2017. There are mutual transformations between "V-shaped" and "S-shaped" inner boundaries during different storm phases, resulting from the competition among electron loss, radial transport and local acceleration. The radial position, onset time, Est (the minimum energy at Lst where the inner boundary starts to exhibit an S-shaped form), and the radial width of S-shaped boundary (ΔL) are quantitatively defined according to the formation of a reversed energy spectrum (electron flux going up with increasing energies from hundreds of keV to ~1 MeV) from a kappa-like spectrum (electron flux steeply falling with increasing energies). The case and statistical results present that (1) The inner boundary has repeatable features associated with storms: the inner boundary is transformed from S-shaped to V-shaped form in several hours during the storm commencement and main phase, and retains in the V-shaped form for several days until it evolves into S-shaped during late recovery phase; (2) ΔL shows positive correlation with SYM-H index; (3) The duration of the V-shaped form is positively correlated with the storm intensity and the duration of the recovery phase; (4) The minimum energy Est are mainly distributed in the range of 100-550 keV. All these findings have important implications for understanding the dynamics of energetic electrons in the slot region and the outer radiation belt during geomagnetic storms.
CryoSat Mission and data products status after 10 years of operation
Authors: Meloni Marco , Bouffard Jerome , Parrinello Tommaso , Webb Erica , Wright Ben , Scagliola Michele , Fornari Marco
Published: March 2020

The ESA Earth Explorer CryoSat-2 was launched on 8 April 2010 and from an altitude of just over 700 km and reaching latitudes of 88 degrees, monitors precise changes in the thickness of terrestrial ice sheets and marine ice. The aim of the CryoSat-2 mission is to determine variations in the thickness of the Earth's marine ice cover and understand the extent to which the Antarctic and Greenland ice sheets are contributing global sea level rise. In its 10 years of operations, CryoSat has achieved its mission objectives and has provided high-quality of data for a number of Earth science applications and opened up new research streams and triggered new scientific questions which have emerged from the previous phases. The purpose of this paper is to provide a general overview of the mission status and provide programmatic highlights in its new extended phase until 2021. It will also provide an overview of CryoSat data products covering both Ocean and Ice processing chains, presenting also the main evolutions and improvements that have implemented to the processors and anticipating evolutions for the future. 

 
SlideforMap – a regional scale probabilistic model for shallow landslide onset analysis and protection forest management
Authors: van Zadelhoff Feiko , Dorren Luuk , Schwarz Massimiliano
Published: March 2020

In the Alps, shallow landslides repeatedly pose a risk to infrastructure and residential areas. For example, dozens of shallow landslides led to the destruction of several houses, killed one person and led to the evacuation of more than 50 houses, multiple road closure for several days in Austria in Nov. 2019. To analyse and predict the risk posed by shallow landslide, a wide range of scientific methods and tools for modelling disposition and runout exists, both for local and regional scale analyses. Most of these tools, however, do not take the protective effect, i.e. root reinforcement, of vegetation into account. Therefore, we developed SlideforMap (SfM), a probabilistic model that allows for a regional assessment of the disposition of shallow landslides while considering the effect of different scenarios of forest cover and management and of rainfall intensity.

SfM uses a probabilistic approach by attributing landslide surface areas, randomly selected from a gamma shaped distribution published by Malamud (2004), to random coordinates within a given study area. For each generated landslide, SfM calculates a factor of safety using the limit equilibrium infinite slope approach. Thereby, the relevant soil parameters, i.e. angle of internal friction, soil cohesion and soil depth, are defined by normal distributions based on mean and standard deviation values representative for the study area. Hydrology is implemented using a stationary flow approach and the topographical wetness index. Root reinforcement is computed based on root distribution and root strength derived from single tree detection data and the root bundle model of Schwarz et al. (2013). Finally, the fraction of unstable landslides to the number of generated slides per raster cells is calculated and used as an index for landslide onset susceptibility. Inputs for the model are a Digital Terrain Model, a topographical wetness index and a file containing positions and sizes of trees.

Validation of SfM has been done by calculating the AUC (Metz, 1978) for three test areas with a reliable landslide inventory in Switzerland. These test areas are in mountainous areas ranging 0.5 – 7.5 km2 with varying mean slope gradients (18 - 28°). The density of inventoried historical landslides varied from 0.4 – 59 slides/km2. This resulted in AUC values between 0.64 and 0.86. Our study showed that the approach used in SfM can reproduce shallow landslide onset susceptibility on a regional scale observed in reality.

SfM was developed to quantify the stabilizing effect of vegetation at regional scale and localize potential areas where the protective effect of forests can be improved. A first version of the model will be released in 2020 by the ecorisQ association (www.ecorisq.org).
Advances in Collaborative Documentation Support for CMIP6
Authors: Pascoe Charlotte , Hassell David , Stockhause Martina , Greenslade Mark
Published: March 2020

The Earth System Documentation (ES-DOC) project aims to nurture an ecosystem of tools & services in support of Earth System documentation creation, analysis and dissemination. Such an ecosystem enables the scientific community to better understand and utilise Earth system model data.

The ES-DOC infrastructure for the Coupled Model Intercomparison Project Phase 6 (CMIP6) modelling groups to describe their climate models and make the documentation available on-line has been available for 18 months, and more recently the automatic generation of documentation of every published simulation has meant that every CMIP6 dataset within the Earth System Grid Federation (ESGF) is now immediately connected to the ES-DOC description of the entire workflow that created it, via a “further info URL”.

The further info URL is a landing page from which all of the relevant CMIP6 documentation relevant to the data may be accessed, including experimental design, model formulation and ensemble description, as well as providing links to the data citation information.

These DOI landing pages are part of the Citation Service, provided by DKRZ. Data citation information is also available independently through the ESGF Search portal or in the DataCite search or Google’s dataset search. It provides users of CMIP6 data with the formal citation that should accompany any use of the datasets that comprise their analysis.

ES-DOC services and the Citation Service form a CMIP6 project  collaboration, and depend upon structured documentation provided by the scientific community. Structured scientific metadata has an important role in science communication, however it’s creation and collation exacts a cost in time, energy and attention.  We discuss progress towards a balance between the ease of information collection and the complexity of our information handling structures.

 

CMIP6: https://pcmdi.llnl.gov/CMIP6/

ES-DOC: https://es-doc.org/

Further Info URL: https://es-doc.org/cmip6-ensembles-further-info-url

Citation Service: http://cmip6cite.wdc-climate.de
Numerical simulation of pyro-convection caused by intense wildfire in Portugal
Authors: Senande Rivera Martín , Miguez-Macho Gonzalo
Published: March 2020

Weather has a major influence on wildfire behaviour, but heat and vapor fluxes produced by fuel consumption can also alter atmospheric conditions. Severe storms can develop from the intense convection that occurs in large wildfires. During Pedrógao Grande (Portugal) 17 June 2017 wildfire, atmospheric storm conditions played a decisive role in fire spread, with the fire becoming uncontrollable and ultimately causing 66 fatalities.

We present here preliminary simulations of the Pedrógrao Grande wildfire with the WRF-FIRE model, identifying the role that the fire could have played in the development of the storm and how the storm could have influenced the spread of the fire.​
Drought impacts on the carbon uptake of an old-growth deciduous forest in Central Germany
Authors: Siebicke Lukas , Moyano Fernando , Knohl Alexander
Published: March 2020

In recent years, Europe has seen hot summers and drought conditions occur with increasing intensity and frequency. Drought and soil water limitations impact on the carbon uptake and release of forests. This study investigates the effect of recent drought events on carbon dioxide exchange of the unmanaged deciduous old-growth forest at the Fluxnet site Hainich (DE-Hai) in the years 2018 and 2019 and compares them to the previous century drought of 2003. During the 2018 event the Hainich site was at the intensity maximum of the Middle European drought event. In combination with shallow soils with low water holding capacity, this lead to severe limitations of available soil water and therefore a to a reduction in carbon fluxes. Comparing the 2003, 2018 and 2019 drought years, we find that anomalies in the annual carbon balances are not only affected by the intensity of the drought events itself but most importantly by the seasonal timing and the balance between anomalies in the carbon uptake and release. 2018 saw a significant reduction in the annual carbon uptake of the forest due to a drought starting early in Spring and limiting fluxes from May and June onwards. Contrary, 2019 experienced a less severe drought, however, the reduction in the annual carbon uptake of about 40% in 2019 was even more extreme than in the previous year. We are able to explain differences between years by two factors: firstly, the uptake deficit during the Summer and Autumn of 2018 was partially compensated by a positive uptake anomaly in Spring and early Summer, and secondly, the severe soil water limitation during the summer of 2018 lead to a decrease of ecosystem respiration, likely dominated by a decrease in soil respiration. Contrary, 2019 saw neither of the two compensating effects and therefore experienced the strongest reduction in net annual carbon uptake of the three drought years investigated. The further development of the carbon sequestration potential of the forest will remain a relevant question given the likely frequent occurence of droughts in the future and the consequences of significant forest damage already observed in 2019.
The recent AMOC variability in the Subpolar Gyre: results across the OVIDE section
Authors: Lherminier Pascale , Mercier Herlé , Perez Fiz F. , Fontela Marcos
Published: March 2020

According to the subpolar AMOC index built from ARGO and altimetry, the AMOC amplitude across the OVIDE section (from Greenland to Portugal) was similar to that of the mid-1990s between 2014 and 2017, i.e. 4-5 Sv above the level of the 2000s. It then returned to average values in 2018. The same index computed independently from the biennial summer cruises over 2002-2018 confirms this statement. Interestingly, despite the concomitant cold and fresh anomaly in the subpolar Atlantic, the heat flux across OVIDE remains correlated with the AMOC amplitude. This can be explained by the paths taken by the North Atlantic Current and the transport anomalies in the subarctic front. In 2014, the OVIDE section was complemented by a section from Greenland to Newfoundland (GA01), showing how the water of the lower limb of the AMOC was densified by deep convection in the Labrador Sea. The spatial patterns of volume, heat, salt and oxygen transport anomalies after 2014 will be discussed at the light of the 2000s average.
Designing services that are more than FAIR with User eXperience (UX) techniques
Authors: Watson Carl , Tvaranavicius Paulius , Kaleem Rehan
Published: March 2020

More and more research data, models and software are being made accessible. This should, in principle, be of real value to the scientific community as well as decision makers, industry and wider society.

However, too often the data is not particularly easy to Find, users can be left confused about terms, conditions and licences, therefore limiting Access. If a user actually manages to identify usable data that is Interoperable with other relevant datasets and services they too often report that the process is not as easy they would like it to be. All of this results in valuable, accessible data remaining unused never mind Re-used.

Taking inspiration from the product design industries and applying the techniques of Service Design and User eXperience (UX) to develop user centric solutions would result in more intuitive, user relevant services that maximise the impact of making data and tools Open and FAIR.

This talk will present three use cases:

UK Geoenergy Observatories: a complex and challenging programme of work to develop the digital infrastructure necessary to open up all research findings from two new Geoenergy testbeds in the UK.

CAMELLIA rain garden calculator: a community engagement and co-design project in which rapid software prototyping led to local residents of a South London housing estate being able to co-design a new green space with environmental scientists and funding bodies.

Geospatial Commission - Data Discoverability project: an evaluation of the current geospatial data portal landscape, involving user research and a UX evaluation of exiting portals. Resulting in a report on future improvements to geospatial data portals being submitted to the UK Government Cabinet Office.

This user centric, design led approach has provided developers with greater clarity on user requirements, resulting in more iterative and rapid deployments of digital services. End users, such as scientists, project managers and other stakeholders, reported a greater sense of ownership and investment in projects in which they are were throughout the research, design and development process.  

 
Climate forcing and committed global warming: GHGs, aerosols and ozone 1970-2010
Authors: Zhao Alcide , Stevenson David , Bollasina Massimi
Published: March 2020

It is crucial to reduce uncertainties in our understanding of the climate impacts of short‐lived climate forcers, in the context that their emissions/concentrations are anticipated to decrease significantly in the coming decades worldwide. Using the Community Earth System Model (CESM1), we performed time‐slice experiments to investigate the effective radiative forcing (ERF) and climate respons to 1970–2010 changes in well‐mixed greenhouse gases (GHGs), anthropogenic aerosols, and tropospheric and stratospheric ozone. Once the present‐day climate has fully responded to 1970–2010 changes in all forcings, both the global mean temperature and precipitation responses are twice as large as the transient ones, with wet regions getting wetter and dry regions drier. The temperature response per unit ERF for short‐lived species varies considerably across many factors including forcing agents and the magnitudes and locations of emission changes. This suggests that the ERF should be used carefully to interpret the climate impacts of short‐lived climate forcers. Changes in both the mean and the probability distribution of global mean daily precipitation are driven mainly by GHG increases. However, changes in the frequency distributions of regional mean daily precipitation are more strongly influenced by changes in aerosols, rather than GHGs. This is particularly true over Asia and Europe where aerosol changes have significant impacts on the frequency of heavy‐to‐extreme precipitation. Our results may help guide more reliable near‐future climate projections and allow us to manage climate risks more effectively.
Loss of available soil organic carbon from afforestation plots: effect of tree species composition and warming
Authors: Jiang Zhenhui , Gunina Anna , Merz Lucas , Yang Yihe , Kuzyakov Yakov , Jones Davey , Smith Andrew R. , Ludwig Bernard
Published: March 2020

Afforestation with pure and mixed-species is an important strategy to improve soil organic carbon (SOC) stocks and restore degraded lands. However, what remains unclear is the stability of SOC to microbial degradation after afforestation and the effect of tree species composition. Moreover, it is important to reveal how sensitive the SOC in afforestation lands is to environmental changes, such as warming. To study the combined effects of warming and the tree species composition on decomposition of SOC by microorganisms and enzyme activities, soils were collected from the monocultural and mixtures of Silver birch (Betula Pendula) and European beech (Fagus Silvatica) (BangorDiversity, UK, 12 years since afforestation) and were incubated for 169 days at 0, 10, 20, 30 °C at 60 % of WHC. The field experiment is arranged into a completely randomized design with n=4. The CO2 efflux was measured constantly, whereas activities of β-glucosidase, chitinase and acid phosphatase, and content of microbial biomass C (MBC) were obtained at the end of the incubation. Results showed that soil cumulative CO2 efflux increased by 34.7–107% with the temperature. Potential enzyme activities were dependent on tree species composition. Warming, but not tree species exhibited a significant impact on the temperature sensitivity (Q10) of soil cumulative CO2 efflux and enzyme activities. The greatest temperature sensitivity (Q10) of total CO2 efflux was found at 10–20 °C and was 2.0–2.1, but that of enzyme activities were found as 0.9–1.1 at 0–10 °C. These results suggest that warming has an asynchronous effect on the SOC decomposition and enzyme activity, and enzymes cannot account for the temperature sensitivity of soil respiration. Thus, thermal adaptations of SOC mineralization is independent of the adaptation of the enzyme pool.
Accommodation of the Cenozoic Tunka Rift Valley at the Ordovician Slyudyanka Collision Zone: insight into volcanic sources, deep-seated inclusions, and seismic tomography models
Authors: Yasnygina Tatyana , Rasskazov Sergei , Ailow Youseph , Chuvashova Irina , Saranina Elena , Mordvinova Valentina , Khritova Mariya
Published: March 2020

On the one hand, Pb isotope data on 18–13 Myr volcanic rocks from the eastern part of the Tunka Valley yield age estimate of garnet-bearing source region in the viscous mantle of ca. 2.2 Byr that might correspond to the age of the Siberian craton mantle. On the other hand, inclusions from basanites show the pressure range that overlaps the pressure estimates for rocks of the Slyudyanka Ordovician collision zone. The lithospheric material corresponds to the transition from spinel-pyroxene to olivine-plagioclase facies of peridotites in the uppermost part of the mantle and lower-middle crust. VS-data show a low-speed zone dipping from the central Tunka valley eastwards under Southern Baikal to a depth of 70 km. This zone ends at the South Baikal – Tunka Valley junction. We suggest that the eastern parts of the Tunka Valley has inherited the Early Paleozoic collision zone between the Hamar-Daban Terrane and Siberian Paleo-Continent and that the lithosphere of the collision zone overlays the viscous mantle related to the Siberian craton.

This work is supported by the RSF grant 18-77-10027.
Air mass source regions associated with enhanced surface melting of the Greenland Ice Sheet
Authors: Mote Thomas , Preece Jonathon , Wachowicz Lori , Mattingly Kyle , Ballinger Thomas
Published: March 2020

The Greenland ice sheet has experienced increased surface melt and mass loss since the mid-1990s. Surface melt and surface mass balance are partially driven by large-scale changes in atmospheric circulation, which can direct anomalously warm and humid air masses over the ice sheet and lead to pulses of extensive melt and high runoff rates. However, the connection between the air mass source regions and ice sheet surface melt is poorly understood. Here we examine extreme melt pulses (>95th percentile melt extent for 3 or more days) for topographically defined regions of the ice sheet during the months of June, July, and August. Daily melt extent is determined from a satellite passive microwave product. The NOAA Air Resources Laboratory HYSPLIT model is used to calculate 10-day back-trajectories leading up to melt pulses. We apply a clustering algorithm separately for each region and initialization altitude to visualize the predominant tracks of air masses that impact the ice sheet during extensive melt events. Potential temperature at 2 PVU is used to trace atmospheric motion prior to melt onset. Particular attention is given to extreme events that led to melt at the highest elevations of the ice sheet, Summit Station. Results show the difference in source region east and west of the ice divide, and the important role of air mass source regions from North America and Europe.
Effects of an advanced land-use scheme and dynamic vegetation on the terrestrial carbon cycle in EC-Earth
Authors: Nieradzik Lars , Wårlind David , Miller Paul , Lindeskog Mats , Anthoni Peter , Arneth Almut , Smith Ben
Published: March 2020

With human land-use activities expected to increase in the future it is important to understand how LULCC (Land-Use Land-Cover Change) activities affect the Earth’s surface, climate and biogeochemical cycles. Here we use the CMIP6 version of the EC-Earth3 Earth System Model (ESM) to assess the impacts of LULCC on surface fluxes of carbon (C) and nitrogen (N). EC-Earth is one of the first ESMs to interactively couple a 2nd generation dynamical vegetation model (LPJ-GUESS) with mechanistic C-N dynamics in soil and vegetation to an atmospheric model. The size, age structure, temporal dynamics and spatial heterogeneity of the vegetated landscape are represented and simulated dynamically in LPJ-GUESS. Such functionality has been argued to be essential to correctly capture biogeochemical and biophysical land-atmosphere interactions on longer timescales and has been shown to improve their representation compared to more common area-based vegetation schemes. The patch based structure of LPJ-GUESS also makes it possible to represent the history (soil, litter status) of a single patch as it might have been involved in several land-use transitions. We focus on the effects of gross land-use transitions (“land-hist”), net land-use transitions (“land-noShiftcultivate”) and fixing land-use at 1850 levels (“land-noLu”).

 

Global carbon pools increase in simulations without LUC while they decline in those applying LUC, with gross-transitions resulting in values around 3% (or 75 Pg) lower than simulations with net-transitions. This is mainly driven by vegetation carbon changes in the tropical to mid-latitude regions where gross-transitions lead to a significantly higher decrease in high vegetation cover. Furthermore, this is reflected differently for different species, e.g. while there is no change in the LAI of boreal needleleaf trees in net-transitions, their presence is significantly reduced in gross transition scenarios giving way to the growth of fast-growing shade-intolerant species. Moreover, fire-fluxes, which in these experiments are mainly driven by fuel-availability, are also lowest in the gross-transition simulations.

Finally, we will show that the level of complexity with which shifting cultivation is treated has implications for the biogeophysical feedbacks in ESMs resulting from changes to surface albedo and latent heat exchange.

The experiments we conducted clearly indicate the benefits of dynamic vegetation and the importance of using gross transitions in land use-change (LUC) studies. 
Beyond model spread: a process-based attribution of uncertainties in stratospheric ozone modelling
Authors: Chabrillat Simon , Huijnen Vincent , Errera Quentin , Debosscher Jonas , Bouarar Idir , Brasseur Guy , Belamari Sophie , Marécal Virginie , Josse Béatrice , Flemming Johannes
Published: March 2020

Intercomparisons between Chemistry-Climate Models (CCMs) have highlighted shortcomings in our understanding and/or modeling of long-term ozone trends, and there is a growing interest in the impact of stratospheric ozone changes on tropospheric chemistry via both ozone fluxes (e.g. from the projected strengthening of the Brewer-Dobson circulation) and actinic fluxes. Advances in this area require a good understanding of the modelling uncertainties in the present-day distribution of stratospheric ozone, and a correct attribution of these uncertainties to the processes governing this distribution: photolysis, chemistry and transport. These processes depend primarily on solar irradiance, temperature and dynamics.

Here we estimate model uncertainties arising from different input datasets, and compare them with typical uncertainties arising from the transport and chemistry schemes. This study is based on four sets of tightly controlled sensititivity experiments which all use temperature and dynamics specified from reanalyses of meteorological observations. The first set of experiments uses one Chemistry-Transport Model (CTM) and evaluates the impact of using 3 different spectra of solar irradiance. In the second set, the CTM is run with 4 different input reanalyses: ERA-5, MERRA-2, ERA-I and JRA-55. The third set of experiments still relies on the same CTM, exploring the impact of the transport algorithm and its configuration. The fourth set is the most sophisticated as it is enabled by model developments for the Copernicus Atmopshere Monitoring Service, where the ECMWF model IFS is run with three different photochemistry modules named according to their parent CTM: IFS(CB05-BASCOE), IFS(MOCAGE) and IFS(MOZART).

All modelling experiments start from the same initial conditions and last 2.5 years (2013-2015). The uncertainties arising from different input datasets or different model components are estimated from the spreads in each set of sensitivity experiments and also from the gross error between the corresponding model means and the BASCOE Reanalysis of Aura-MLS (BRAM2). The results are compared across the four sets of experiments, as a function of latitude and pressure, with a focus on two regions of the stratosphere: the polar lower stratosphere in winter and spring - in order to assess and understand the quality of our ozone hole forecasts - and the tropical middle and upper stratosphere - where noticeably large disagreements are found between the experiments.
An emergent constraint on transient warming from simulated historical warming in CMIP6 models
Authors: Nijsse Femke J. M. M. , Cox Peter M. , Williamson Mark S.
Published: March 2020

The transient climate response (TCR), transient warming for a doubling of CO2, contributes the biggest uncertainty to estimates of the carbon budgets consistent with the Paris targets. In the IPCC 5th Assessment Report (AR5), the stated ‘likely’ range of TCR was given as 1.0 to 2.5K, with a central estimate which was broadly consistent with the ensemble mean of the CMIP5 Earth System Models (ESMs) available at the time (1.8 +/- 0.4 K) . Many of the latest CMIP6 ESMs have larger climate sensitivities, with 6 of 23 models having TCR values above 2.5 K, and an ensemble mean TCR of 2.1 +/- 0.4 K. On the face of it, these latest ESM results suggest that the IPCC likely range of TCRE may need revising upwards, which would cast further doubt on the feasibility of the Paris targets.

We analyse the CMIP6 models through an emergent constraint approach which relates the value of TCR to the global warming from 1970 onwards. We confirm a consistent emergent constraint on TCR when we apply the same method to CMIP5 model. Our emergent constraint on TCR benefits from both the large range of TCR values across the CMIP6 models, and also from the extension of the historical simulations into a period when the uncertain changes in aerosol forcing have had a far less significant impact on the trend in global warming.

We show that rather than increasing the uncertainty in climate sensitivity, the CMIP6 models help to further constrain the likely range of TCR to 1.5-2.2 K. In CMIP6, diagnosed emissions at carbon doubling was found to be independent of TCR, so that a constraint on TCR directly leads to a constrained estimate of TCRE, with a likely range of 1.3 – 2.0 K per EgC. 
Stormflow behaviour in blanket peat catchments affected by severe wildfire: implications for natural flood management
Authors: Shuttleworth Emma , Evans Martin , Allott Tim , Kay Martin , Johnston Adam , Alderson Danielle , Edokpa Donald , Holden Joseph , Milledge David , Goudarzi Salim , Chandler David , Brown David
Published: March 2020

The restoration of damaged UK peatlands is a major conservation concern, and landscape-scale restoration is extensive in areas of upland Britain. Peatland headwater catchments are important areas of hillslope runoff production, and over the last decade there has been increasing focus on how restoration schemes can reduce downstream flood risk through natural flood management (NFM). Stormflow in degraded catchments can be incredibly flashy, as water is quickly evacuated from hillslopes across bare peat surfaces and through erosional gullies, but there is increasing evidence that restoration by revegetation and damming of channels can significantly slow the flow of water.

Recent major peatland wildfires in the UK have focused attention on the effects of wildfire and post-wildfire restoration on the hydrology of peatland catchments, but to date, relatively little is known about the effects of wildfire on peatland flood hydrology. Current understanding is largely drawn from process studies, with evidence suggesting that severely burnt peatlands will have flashier hydrograph responses to rainfall events, with higher peak flows relative to unburnt peatlands. This assumption is based on three key factors which promote rapid overland flow: (i) the development of hydrophobic crusts due to high intensity fires, (ii) the clogging of peat pores by ash, and (iii) removal of vegetation cover reducing surface roughness. Further influences on runoff production could result from changes in water table or post-fire peat shrinkage and cracking.

This paper details stormflow characteristics from nine gullies in an area of peatland affected by the high-severity Saddleworth wildfire which burned over 1000 hectares of UK peatland in June and July 2018. This field area is upstream of the community of Stalybridge, which the Environment Agency had highlighted as a priority community at risk of flooding. We compare this behaviour to catchments that were unaffected by the fire. Preliminary findings suggest that the fire affected gullies produce highly variable stormflow behaviour, with some sites producing discharges similar to bare peat sites, while others are more similar to relatively intact catchments. The planned restoration of this area has great potential to provide NFM benefits.
Auroral omega bands are a significant cause of large geomagnetically induced currents
Authors: Apatenkov Sergey , Pilipenko Vyacheslav , Gordeev Evgeniy , Viljanen Ari , Juusola Liisa , Belakhovsky Vladimir , Sakharov Yaroslav , Selivanov Vasily
Published: March 2020

The strongest event of geomagnetically induced currents (GIC) detected by the North-West Russian GIC network occurred during the main phase of the magnetic storm on June 28-29, 2013. Extremely high values, 120 A, were recorded in the 330 kV transformers on Kola Peninsula in the 04--07 magnetic local time (MLT) sector. The Defense Meteorological Satellite Program (DMSP) spacecraft took a sequence of ultraviolet (UV) auroral images in the southern hemisphere and observed multiple omega bands. The ionospheric equivalent electric currents based on the International Monitor for Auroral Geomagnetic Effects (IMAGE) magnetometer network reveal a sequence of current vortex pairs moving eastward with the speed of 0.5-2.5 km/s, that fits to the electrodynamics scheme of omega bands. Although the temporal variations of the associated current system are slow, the omega bands can be responsible for strong magnetic variations and GIC due to fast propagations of currents in the azimuthal direction.  The first steps towards the statistica study of the highest GIC recorded at Vykhodnoy transformer show that about 50% of events have properties similar to the comprehensively studied 29 June 2013 case.
Fluvial flooding hazard assessment in Northern Italy: potential and informativeness of different geomorphic classifiers
Authors: Castellarin Attilio , Persiano Simone , Samela Caterina , Magnini Andrea , Bagli Stefano , Mazzoli Paolo , Luzzi Valerio
Published: March 2020

The steady increase of economic losses and social consequences caused by flood events in Europe, as a result of the combined effects of anthropization (e.g. land-use and land-cover changes) and climate change, calls for updated and efficient technologies for assessing pluvial, fluvial and coastal flood hazards and risks. In this context, the EIT-Climate KIC SaferPLACES () project aims at exploring and developing innovative and simplified modelling techniques to assess and map flood hazard and risk in urban environments under current and future climates. Concerning fluvial flooding, detailed inundation maps can be accurately obtained by means of hydrological and hydraulic numerical models, whose application, though, is often very resource intensive. For this reason, consistent and harmonized national flood hazard maps are still lacking in many countries of the world. Several studies have proved that flood-prone areas can be delineated by considering linear binary geomorphic classifiers, which are computed by analysing Digital Elevation Models, DEMs, and whose threshold values are calibrated relative to existing hydraulic flood hazard maps. One of these indices, the so-called Geomorphic Flood Index (GFI), was recently shown to be cost-effective, reliable and efficient for identifying flood-prone areas in several test sites in the United States, Africa and Europe. As part of the activities of SaferPLACES, in this study we test different geomorphic classifiers (GFI included) for the identification of flood-prone areas in a wide area in Northern Italy (c.a. 100000 km2, including Po, Adige, Brenta-Bacchiglione and Reno river basins). We refer to the recently compiled MERIT (Multi-Error-Removed Improved-Terrain) DEM, a 3sec-resolution (~90m at the equator) DEM developed by removing multiple error components from existing spaceborne DEMs. As reference maps for the calibration, we select the flood hazard maps provided by (i) the Italian Institute for Environmental Protection and Research (ISPRA), and (ii) the Joint Research Center (JRC) of the European Commission. Our study confirms the better performances of GFI compared to other geomorphic classifiers, also providing useful information regarding the sensitivity of GFI threshold values relative to different reference hazard maps; it also suggests as a promising avenue for future researches the combination of multiple geomorphic indices through data-driven approaches and artificial intelligence.
From Drip To Plate: Did Subduction Start in Archaean?
Authors: Çetiner Uğurcan , Göğüş Oğuz , Rozel Antoine
Published: March 2020

The evolution from stagnant/episodic lid to modern-day plate tectonics on earth is not well understood. Geochemical and geomorphological findings indicate that Archaean Eon is the most likely candidate for the onset of plate tectonics. In order to have plate tectonics, the oceanic lithosphere has to be denser than the asthenosphere and subducting slabs must be rheologically strong so that it would stay intact/undeformed during subduction. Our study focuses on investigating the initiation of subduction on the margins of an Archaean craton/continent based on the subcretion tectonic model of Bédard (2018). Here, we use 2-D mantle convection models (StagYY) to understand the controlling parameters for possible subduction or lithospheric downwellings. A 230 km thick craton accompanied by a 60 km thick oceanic lithosphere on both sides is introduced into the model setup. The model domain is divided by 64 vertical cells and 512 lateral cells corresponding to 660 km depth and 2000 km length. Both for the upper and lower boundary, free-slip surface conditions are used. Left and right boundaries are periodic. Velocities are forced to be zero until a critical depth of 60 km, after that a sub-lithospheric mantle flow of 4 cm/yr imposed into the model which is a proxy for a disturbance generated within the mantle by the “overturn upwelling zones”. Our results indicate that cratonic keels can be mobilized by the sub-lithospheric mantle winds and what happens afterward is highly dependent on the surface yield stress, eclogite phase transition depth, deformation mechanism and, most importantly, reference mantle viscosity. Lower viscosity (1019 Pa s) models resulted in a stagnant-lid regime while the others with the increased viscosity (1020 Pa s – 1021 Pa s) yielded in a transition from stagnant to plate-like behaviors.
Improving hydrologic model realism by using stable water isotopes
Authors: Beria Harsh , Benoit Lionel , Ceperley Natalie , Michelon Anthony , Larsen Joshua R. , Mariéthoz Grégoire , Schaefli Bettina
Published: March 2020

The last century of hydrological research has led to significant improvements in representing different hydrological processes in rainfall-runoff models. With widely available streamflow data, such models are typically calibrated against this reference time series, which can limit their predictive power. One option to improve the realism of rainfall-runoff models is by incorporating environmental tracers such as stable isotopes of water, water temperature and electrical conductivity within the modeling setup. Conventionally, stable water isotopes have been used to learn more about the dominant hydrological processes that occur within a given catchment, which generally helps improve the hydrologic model structure, but often at the cost of increased model complexity to simulate the tracer concentration along with streamflow.

In this study, we develop a framework to incorporate stable water isotopes in continuous hydrological modeling, without significantly increasing model complexity. In the first step, stable water isotopes are used along with streamflow recession analysis to initialize the model state variables. After that, a Bayesian mixing model is used to infer the proportion of slow vs fast subsurface flow, and the results are used as additional constraints during the model calibration. This framework is extensively tested in a snow-dominated experimental catchment called Vallon de Nant, located in the Southwestern Swiss Alps (1189-3051 m. a.s.l.). During the presentation, we will discuss the advantages and limitations of such a modeling approach and how it can be extended to other experimental catchments.