bluuebunny/crossref_metadata_2025 huggingface dataset:
Simple "Reactor model" of relativistic runaway electron avalanches dynamics
Authors: Stadnichuk Egor , Zemlianskay Daria , Efremova Victoria
Published: March 2021

A possible mechanism responsible for Terrestrial Gamma-ray Flashes (TGFs) is feedback in the relativistic runaway electron avalanches (RREA) dynamics. In this research, a new way of RREAs self-sustaining is suggested. This self-sustaining feedback can be described in the following way. Let the thundercloud consist of two regions with the electric field so that runaway electrons accelerated in one region move in the direction of another one and vice versa. For instance, such an electric field structure might appear with one positive charge layer situated between two negative charge layers. In this system, the following feedback mechanism occurs. An RREA developing in one region will produce bremsstrahlung gamma-rays. These gamma-rays will propagate into another region and produce RREAs within it. These RREAs will develop backward and radiate gamma-rays, which will penetrate the first region, generating secondary RREAs. In this way, the primary avalanche reproduced itself by the gamma-ray exchange between two sideways oriented areas with the electric field. In this work, it is shown that the electric field values required for TGF generation by this mechanism are lower than values required in Relativistic Feedback Discharge Model.
The ecology of heterogeneity: soil bacterial communities and C dynamics
Authors: Raynaud Xavier , Schmidt Hannes , Nunan Naoise
Published: March 2021

Heterogeneity is a fundamental property of soil that is often overlooked in microbial ecology. Although it is generally accepted that the heterogeneity of soil underpins the emergence and maintenance of microbial diversity, the profound and far-reaching consequences that heterogeneity can have on many aspects of microbial ecology and activity have yet to be fully apprehended and have not been fully integrated into our understanding of microbial functioning.

Heterogeneity in soils has multiple facets, from the molecular heterogeneity of the diversity of substrate available, the activity heterogeneity due to the activity of microbial species and the spatial heterogeneity of the soil structure and the distribution of organisms.

In this contribution we present a simple, spatially explicit model that can be used to understand how the interactions between the heterogeneity of decomposers (in terms of species and spatial distribution) and environmental heterogeneity (in terms of the diversity of substrates and their spatial distribution) affect the bacterial decomposition of organic matter. We found that environmental heterogeneity is a key element in determining the variability of the decomposition process.
Observations of New Particle Formation events during summertime in Helsinki
Authors: Thakur Roseline , Dada Lubna , Beck Lisa , Chan Tommy , Sulo Juha , Marbouti Marjan , He Xu-Cheng , Lampilahti Janne , Lampimäki Markus , Quéléver Lauriane L.J , Tham Yee Jun , Sarnela Nina , Lehtipalo Katrianne , Kulmala Markku , Sipilä Mikko , Jokinen Tuija
Published: March 2021

Aerosols can originate from different sources and undergo various formation pathways. New Particle formation (NPF) events occur when precursor vapors nucleate and vapors with low volatility condense on the critical nuclei enabling them to grow to cloud condensation nuclei (CCN) relevant sizes. As CCN, these aerosols affect the occurrence of clouds and their lifetime on local, regional and global level.  Many studies have investigated new particle formation events from various sites ranging from urban areas, boreal forests to pristine locations; however, there is still a dearth of studies investigating coastal new particle formation, which is a complex phenomenon due to the dynamic and ever-changing atmospheric conditions at the coast.  A comprehensive study of particle number distributions and aerosol forming precursor vapors was carried out in a coastal capital city of Finland, Helsinki, during the summer of 2019. The experimental setup comprising of a nitrate-based chemical ionization atmospheric pressure interface time of flight mass spectrometer (CI-APi-TOF), a neutral cluster-air ion spectrometer (NAIS) and a particle size magnifier (PSM) were housed in and around the SMEAR III station in Kumpula Science campus. SMEAR III is a unique site situated in a semi-urban yet coastal location. The period of experiment coincided with the cyanobacterial bloom in the coastal areas of Finland and in the Baltic Sea region. Our study recorded several regional NPF and aerosol burst events during this period. High concentrations of sulfuric acid was found to be associated with the regional NPF events whereas increasing iodic acid concentrations was mostly associated with the initiation of burst events. The sources of sulfuric acid and iodic acid has been carefully evaluated in this study.

 
Assessment of regime shifts and risk of extreme precipitation in urban regions in Illinois, USA
Authors: Khan Manas , Bhattarai Rabin
Published: March 2021

Intensification of extreme precipitation, especially in urban regions, is mostly responsible for causing flash floods leading to significant damages of civil infrastructure and loss of human lives throughout the world. Understanding the pattern and risk of these extreme events could be immensely beneficial in the planning and managing built infrastructure under climate change. Although many studies have been conducted addressing extreme precipitation events, there is still a lack of understanding of these events and associated risk at the regional scale in a non-stationary environment.  The objectives of this study were to (a) identify the regime shifts in extreme precipitation (R95) using Fisher Information in Illinois, USA; (b) determine the trend of R95 applying Modified Mann-Kendall method; (c) quantify the risk associated with R95 applying Extreme Value Theory (EVT). Daily precipitation data from 1950-2010 was collected for 78 urban gauge stations from the United States Department of Agriculture –Agriculture Research Service (USDA-ARS) database, including Cooperative Observer Network (COOP), Weather-Bureau-Army-Navy (WBAN), and Midwestern Regional Climate Center (MRCC). The future precipitation data was collected for regional climate models (RCMs) under two representative concentration pathway (RCP) scenarios (i.e., RCP 4.5 & RCP 8.5) for 2021-2100 from the NA-CORDEX data archive. All the future data was bias-corrected using gauge station data applying the quantile mapping technique. Initial results showed a significant bias in the RCM dataset. Further, most of the regime shits in R95 were identified between 1971-1985 in the urban regions.
Water vapor isotopologues (H216O, H218O and HD16O) by ground-based FTIR spectroscopy in central Mexico
Authors: Zuber Alain , Stremme Wolfgang , Magaldi Adolfo , Grutter Michel , Rivera Caludia , Bezanilla Alejandro , Taquet Noemie , Blumenstock Thomas , Hase Frank , Schneider Matthias
Published: March 2021

Knowledge about water vapor isotopologues is a useful tool in the study of the hydrological cycle. Total columns of water vapor isotopologues (H216O, H218O and HD16O) are measured by ground-based solar absorption FTIR spectroscopy at Altzomoni (3985 m.a.s.l, 19.12ºN, 98.66ºW), a high altitude subtropical remote background site in central Mexico (Barthlott et al., 2017). In the contribution we present the time series of the isotopic composition of water vapor columns and profiles above central Mexico and analyze differences in the isotopic ratios of H216O, H218O and HD16O between the rain and dry seasons of the year: in the rain season, changes in the isotopic ratios might be dominated by the diurnal cycle, which correlates with the relative humidity, temperature and dew point, while isotopic ratio in the dry season might depend more on the origin of the air parcels and transportation. We discuss the hydrological cycle in central Mexico using the relationship between light and heavy isotopes, and how this relationship gives valuable information about the pathways, sources and transport.
Detecting ground motion in Schleswig-Holstein from radar satellite data
Authors: Hoogestraat Dieter , Sudhaus Henriette , Omlin Andreas
Published: March 2021

The near-surface geology of northern Germany is characterized by glacial deposits, deformed by rising Permian and Upper Triassic salt structures. Ground motions potentially associated with salt tectonic processes are very slow and are superimposed by signals of e.g. hydrological and anthropogenic sources. To measure them requires the detection of motion rates in the range of a few millimeters per year with sufficient spatial coverage. For large areas little is known about the rates and the characteristics of ground motions, even though they directly affect anthropogenic infrastructure and could have an impact on the future use of the underground for storage purposes or the exploitation of geothermal energy.

To measure ground motion, we use radar interferometric time series data provided by the German Aerospace Center and the Federal Institute for Geosciences and Natural Resources' Ground motion service. These data are based on Synthetic Aperture Radar images acquired by ESA's ERS and Sentinel satellites. Time-series analyses are possible for temporally stable backscattering objects (persistent scatterers) on the ground. Generally, this results in spatially dense observations over built-up areas and sparse observations over rural areas.

We use a set of geostatistical methods to analyze these time series data. We see signals of large-scale surface-deforming processes such as the subsidence of the marshes and small-scale signals like the swelling of Permian anhydrite at the Segeberger "Kalkberg". And we can observe subsidence processes over the historic town of Lübeck.

Our work extends the area of application of the PS-InSAR technique from areas with high motion rates to regions with particulary low motion rates. We discuss methods that can be used to link ERS data to the Sentinel-1 data, in particular, to separate long-term motion processes from short-term effects. We are working on techniques that shall help to decompose different signal sources. Finally, we aim to prepare a set of tools, that can be used by the community.
Ice-shelf Basal Melt Rates in the Energy Exascale Earth System Model (E3SM)
Authors: Comeau Darin , Asay-Davis Xylar , Begeman Carolyn , Hoffman Matthew , Lin Wuyin , Petersen Mark , Price Stephen , Roberts Andrew , Van Roekel Luke , Veneziani Milena , Wolfe Jonathan , Turner Adrian
Published: March 2021

The processes responsible for freshwater flux from the Antarctic Ice Sheet (AIS) -- ice-shelf basal melting and iceberg calving -- are generally poorly represented in current Earth System Models (ESMs). Here, we document the first effort to date at simulating the ocean circulation and exchanges of heat and freshwater within ice-shelf cavities in a coupled ESM, the Department of Energy's Energy Exascale Earth System Model (E3SM). As a step towards full ice-sheet coupling, we implemented static Antarctic ice-shelf cavities and the ability to calculate ice-shelf basal melt rates from the heat and freshwater fluxes computed by the ocean model. In addition, we added the capability to prescribe forcing from iceberg melt, allowing us to realistically represent the other dominant mass loss process from the AIS. In global, low resolution (i.e., non-eddying ocean) simulations, we find high sensitivity of modeled ocean/ice shelf interactions to the ocean state, which can result in a tipping point to high melt regimes under certain ice shelves, presenting a significant challenge to representing the ocean/ice shelf system in a coupled ESM. We show that inclusion of a spatially dependent parameterization of eddy-induced transport reduces biases in water mass properties on the Antarctic continental shelf. With these improvements, E3SM produces realistic and stable ice-shelf basal melt rates across the continent under pre-industrial climate forcing. We also show preliminary results using an ocean/sea-ice grid that makes use of E3SM’s regional-refinement capability, where increased resolution (down to 12km) is placed in the Southern Ocean around Antarctica, bypassing the need for parameterization of eddy-induced transport in this region. The accurate representation of these processes within a coupled ESM is an important step towards reducing uncertainties in projections of the Antarctic response to climate change and Antarctica's contribution to global sea-level rise.
Democratizing and Densifying Low Noise Long Period Broadband Stations
Authors: Bainbridge Geoffrey , Hamilton Valarie , Parker Timothy
Published: March 2021

The Streckeisen STS-1 set a very high performance and lasting broadband (VBB) sensor standard that has been hard to match by other instruments, but these sensors also required a very careful emplacement and shielding from environmental changes and conditions, along with the high costs of ensuring the conditions for this level of instrument performance.  Recent developments have demonstrated equivalent and broader bandwidth sensors that enable deploying these types of sensors in most any terrestrial environment.  These new instruments, in many types of form factors, all magnetically shielded, open up new opportunities for continuing and expanding these VBB observations, democratizing the observations of these long period signals and opening up the possibilities of better performance through deep boreholes and observations of less developed sites that have harsher environmental conditions, along with recapitalizations of sites where STS-1s are no longer supported.   We will describe recent testing results of Trillium 360 GSN vault, borehole, and posthole sensors as well as the Horizon 360 from many observatories and new potential use cases, some in polar environments that were impractical until now, and discuss development of the new Horizon 360 OBS.
Caribbean slab dynamics beneath northwest South America from SKS and Local S splitting
Authors: Cornthwaite John , Niu Fenglin , Levander Alan , Schmitz Michael , Prieto Germán , Dionicio Viviana
Published: March 2021

     The southernmost edge of the Caribbean (CAR) plate, a buoyant large igneous province, subducts shallowly beneath northwestern South America (NWSA) at a trench that lies northwest of Colombia. Recent finite frequency P-wave tomography results show a segmented CAR subducting at a shallow angle under the Santa Marta Massif to the Serrania de Perijá (SdP) before steepening while a detached segment beneath the Mérida Andes (MA) descends into the mantle transition zone. The dynamics of shallow subduction are poorly understood. Plate coupling between the flat subducting CAR and the overriding NWSA is proposed to have driven the uplift of the MA. In this study we analyze SKS shear wave splitting to investigate the seismic anisotropy beneath the slab segments to relate their geometry to mantle dynamics. We also use local S splitting to investigate the seismic anisotropy between the slab segments and the overriding plate. The data were recorded by a 65-element portable broadband seismograph network deployed in NWSA and 40 broadband stations of the Venezuelan and Colombian national seismograph networks.

     SKS fast polarization axes are measured generally trench-perpendicular (TP) west of the SdP but transition to trench-parallel (TL) at the SdP where the slab was imaged steepening into the mantle, consistent with previous studies. West of the MA the fast axis is again TP but transitions to TL under the MA. This second transition from TP to TL is likely due to mantle material being deflected around a detached slab under the MA. Local S fast polarization axes are dominantly TP throughout the study area west of the Santa Marta Massif and are consistent with slab-entrained flow. Under the Santa Marta Massif the fast axis is TL for reasons we do not yet understand.
Exploring causal relationships between vegetation coverage and the environmental parameter of Budyko-type models in the Nakanbe nested watersheds in West African Sahel
Authors: Gbohoui Patrick Yetchékpo , Fowé Tazen , Paturel Jean-Emmanuel , Yacouba Hamma
Published: March 2021

Abstract:

Budyko's conceptual framework is recognized in hydrology for its concise and accurate representation of long-term water and energy balances of watersheds. Based on the climate-environment coevolution, Budyko-type models capture the signature of environmental dynamics through climate. Many studies have shown a good correlation between the environmental parameter (u) of Budyko-type models and the vegetation coverage (M), but the analysis of the causal relationships between these two parameters has often received little attention. In this study, Convergent Cross Mapping, a causal discovery method, was applied to identify the causality between u and M from seven nested watersheds (areas ranging between 38 and 21,178 km2) of the Nakanbe River located in West African Sahel. The Budyko-type model developed by Chen and Sivapalan (2020) was forced with the climate data (precipitation, potential evapotranspiration, and actual evapotranspiration) to calculate u values for 11-years moving windows between 1977 and 2018. The vegetation coverage (M) was deduced from the Normalized Difference Vegetation Index. The results showed causal relationships between vegetation coverage and Budyko model parameter (convergence at a positive prediction skill) for all the watersheds. The causal influence detected is reciprocal (M influences u, and u influences M: M⇆u) for four of the seven watersheds studied. These results highlighted the existence and reciprocity of climate-environment interactions at different spatial scales.

Keywords:

Causal relationships, Budyko-type models, climate-environment interactions, Nakanbe River watersheds.
Numerical Simulations of the Evaporating Sea Surface Under Extreme Winds
Authors: Sroka Sydney , Emanuel Kerry
Published: March 2021

Since air-sea enthalpy and momentum fluxes control a tropical cyclone’s intensification rate, increasing the accuracy of the associated bulk parameterizations is crucially important for improving forecast skill. Despite the powerful influence that sea spray has on air-sea enthalpy and momentum fluxes, most state-of-the-art tropical cyclone forecast models do not incorporate the microphysics of sea spray evaporation into their boundary layer flux schemes. We present the results from direct numerical simulations of the evaporating sea surface subject to a strong wind forcing to help evaluate the parameterizations of bulk exchange coefficients of momentum and enthalpy. By developing microphysics-based bulk parameterizations, the influence that sea spray exerts on tropical cyclone intensification can be more accurately simulated and intensity forecasts could be improved.
Statistical analysis of model wind data for the Mediterranean Sea 
Authors: Ghani Mahmud Hasan , Pinardi Nadia , Trotta Francesco
Published: March 2021

The focus of this study is to analyze the probability distribution functions of model wind data over the Mediterranean Sea. The atmospheric wind data set is composed by ECWMF analyses for the period 2010-2019. A single grid point statistical method is applied to the Mediterranean Sea for both wind components and amplitude. The pdf (probability distribution function) of the wind components is Gaussian while the amplitude is Weibull. In addition, sensitivity experiments are done to compare the Weibull with the Exponential Weibull pdfs, showing almost identical patterns for both distributions. The use of two parameters Weibull distribution is widely accepted to represent the statistical structure of surface wind, while three parameters Exponential Weibull distribution mostly refers to extreme events. The pdf parameter distribution in the Mediterranean Sea is shown for the first time to be associated with specific wind structures such as Mistral and Etesian winds. This study confirms the previous results from Chu (2009) for oceanic currents and by Drobinski (2015) for wind station data, both cases showing the two parameter Gaussian pdf for wind components and Weibull pdf for wind amplitude. The knowledge of these distributions will help to improve the ensemble ocean forecast as for the setting of initial conditions of ocean forecasts where atmospheric forcing is crucial to quantify the forecast errors.
Attributing temperature extremes in the Euro-Atlantic region to Arctic Sea Ice changes using a framework of conditional extreme event attribution
Authors: Riebold Johannes , Richling Andy , Rust Henning , Ulbrich Uwe , Handorf Dörthe
Published: March 2021

Over the last century and decades, Arctic climate change has been detected coming along with a rapid decrease of Arctic sea ice extent and a much faster warming of Arctic regions compared to global average. At the same time, an increasing number of record-breaking extreme weather events has been observed also over midlatitudes. In this respect, several studies proposed and studied dynamical Arctic-midlatitude pathways suggesting that Arctic sea ice retreat may not only have local impacts on the polar atmosphere but is also linked to weather and climate in midlatitudes.

In this study, we aim to assess to what extent temperature extremes in the Euro-Atlantic region may be attributed to Arctic sea ice changes. Therefore, in the context of circulation regimes we apply a framework of conditional extreme event attribution to ECHAM6 time slice simulations forced under different sea ice scenarios. As extreme events are generally strongly conditioned and dynamically-driven by specific atmospheric flow configurations, this will help to separate the overall effect induced by Arctic sea ice changes into its thermodynamical and dynamical contributions. This is also motivated by previous studies indicating that sea ice retreat might influence the occurrence probability of certain circulation regimes or blocking patterns and therefore may impact potential dynamical drivers of such extremes.

 
Lagrangian analysis of the northern polar vortex split in April 2020 during development of the Arctic ozone hole
Authors: Curbelo Jezabel , Chen Gang , Mechoso Carlos R.
Published: March 2021

The evolution of the Northern Hemisphere stratosphere during late winter and early spring of 2020 was punctuated by outstanding events both in dynamics and tracer evolution. It provides an ideal case for study of the Lagrangian properties of the evolving flow and its connections with the troposphere. The events ranged from an episode of polar warming at upper levels in March, a polar vortex split into two cyclonic vortices at middle and lower levels in April, and a remarkably deep and persistent mass of ozone poor air within the westerly circulation throughout the period. The latter feature was particularly remarkable during 2020, which showed the lowest values of stratospheric ozone on record.

 

We focus on the vortex split in April 2020 and we examine this split at middle as well as lower stratospheric levels, and the interactions that occurred between the resulting two vortices which determined the distribution of ozone among them. We also examine the connections among stratospheric and tropospheric events during the period.

 

Our approach for analysis will be based on the application of Lagrangian tools to the flow field, based on following air parcels trajectories, examining barriers to the flow, and the activity and propagation of planetary waves. Our findings confirm the key role for the split played by a flow configuration with a polar hyperbolic trajectory and associated manifolds. A trajectory analysis illustrates the transport of ozone between the vortices during the split. We argue that these stratospheric events were linked to strong synoptic scale disturbances in the troposphere forming a wave train from the north Pacific to North America and Eurasia.

 

Reference: J. Curbelo, G. Chen,  C. R. Mechoso. Multi-level analysis of the northern polar vortex split in April 2020 during development of the Arctic ozone hole. Earth and Space Science Open Archive. doi: 10.1002/essoar.10505516.1

 

Acknowledgements: NSF Grant AGS-1832842, RYC2018-025169 and EIN2019-103087.
Identifying different types of individual flood precautionary behaviour from panel data
Authors: Berghäuser Lisa , Bubeck Philip , Hudson Paul , Thieken Annegret H.
Published: March 2021

Individual precautionary behaviour towards and in response to flooding has received much attention in current research, as precautionary behaviour can reduce flood impacts considerably. Therefore, private precautionary measures are increasingly considered in integrated flood risk management plans. Integrated flood risk management requires that all stakeholders threatened by flooding undertake action to limit adverse impacts. However, our current understanding of private precautionary measure employment has mostly been drawn from cross-sectional studies, i.e. data from one-time snapshots. While cross-sectional data has its uses in understanding individual behaviour and its drivers, other questions require the use of panel data, i.e. repeated surveys of the same individuals in order to correctly identify and understand temporal behavioural dynamics which cross-sectional data is unable to capture.
Here we use panel data to identify different types of dynamic adaptive behaviour. We applied and compared two classification methods to panel data from 227 individual households who were repeatedly interviewed across Germany about their implementation of precautionary measures after the widespread flood of June 2013: Latent Class Growth Analysis (LCGA) and Cluster Analysis based on k-means for longitudinal data. Results indicate three different groups of adaptive behavior over the survey period that are identified by both classification methods: (I) a group that maintains a “high standard” of protection, (II) a “performer” group that implements a fare share of precautionary measures after the flood and during the survey period and (III) a “non adaptive” group that shows little or no implementation of precautionary measures. As a considerable share of flood-prone residents did almost not adapt, results indicate that specific risk communications and funding schemes are needed in order to trigger adaptation of this group.
A general approach for analytically upscaling the exact root water uptake equations despite heterogeneous soil moisture at the soil-root interface
Authors: Bouda Martin , Vanderborght Jan , Javaux Mathieu
Published: March 2021

Recent advances in scaling up water flows on root system networks hold promise for improving predictions of water uptake at large scales. These developments are particularly timely, as persistent difficulties in getting Earth system models to accurately represent soil-root water flows, especially under drying or heterogeneous soil moisture conditions, are now a major obstacle describing the water limitation of terrestrial fluxes.

One recently developed upscaling formalism has been shown to be both free of discretisation error in flow predictions regardless of scale and with computational cost linearly diminishing with the number of soil subdomains considered. What has been missing from this approach, however, is a proven method to apply it generally – i.e. to an arbitrary root system architecture discretised on an arbitrary grid.

The work presented here demonstrates a general algorithm that can be applied to a wide range of root system architectures (the only assumption being that only one lateral root originates at one point along a parent root) discretised on a grid consisting of a series of soil layers of variable thickness, as is common in Earth system models. It is further shown theoretically that both of these restrictions can in principle be relaxed and that this approach can in principle be extended to conditions of soil moisture heterogeneity – i.e. situations where each root segment in a soil grid cell faces a different water potential at the soil-root interface.

This work represents both a practical advance bringing broad applicability to this upscaling approach and a major theoretical advance as exact solutions for water uptake under conditions of soil moisture heterogeneity within grid cells were previously unknown. While obtaining exact solutions despite heterogeneity within the grid cell requires a way of finding the overall mean soil water potential faced by the plant, this advance nevertheless points to possible directions of future research for overcoming the major hurdle of soil moisture heterogeneity.
Evaluation of the ECMWF Operational Forecasting System for Probabilistic Flood Prediction in Mexico City
Authors: López López Marco Rodrigo , Pedrozo Acuña Adrián
Published: March 2021

Floods and puddles are incidents that occur every year in Mexico City. The surface runoff that occurs in areas of hills and mountains, such as torrential rains where precipitation is greater than the drainage capacity, are the main factors that give rise to floods in the city. The measures that have been implemented to control floods have focused more on reactive planning instead of implementing prevention measures; so the city is completely dependent on its drainage system to mitigate flooding. For these reasons, the forecast has become essential to respond to the demand for better risk management due to the exposure of infrastructure and people to flood events; and coupled with the uncertainty of future events in Mexico City.

Rainfall is the main source of uncertainty in flood prediction; That is why, in recent years, the Numerical Climate Prediction Models (NWP) have focused on the generation of Ensemble Prediction Systems (EPS); which constitute a feasible method to predict the probability distribution function of atmospheric evolution.

The objective of this work is to evaluate the Operational Ensemble Prediction System issued by the European Centre for Medium-Range Weather Forecasts (ECMWF) to open the doors to the development of a Flood Forecasting System in Mexico City. The EPS was evaluated against observed rainfall for two study zones: Mexico Valley Basin and Mexico City, where for the latter, the forecasts were compared against information of real time observed rainfall. To carry out an objective analysis of the quality of the forecast, metrics were applied for the scalar attributes: precision, reliability, resolution, discrimination and performance. The probabilities given by the ensembles were estimated using a predictive model.

The results show the EPS do represent the probability distribution of the observed events. The first 36 hours of forecasting are the most reliable, after which uncertainty increases. Finally, the predictive model shows good performance in estimating probabilities according to the area under the receiver operating characteristic curve.
Analyses on salt-marsh vegetation composition changes in the Venice lagoon in the last twenty years
Authors: Yang Zhicheng , Silvestri Sonia , Marani Marco , D'Alpaos Andrea
Published: March 2021

Coastal salt-marshes are important eco-geomorphic features of coastal landscapes providing valuable ecosystem services, but unfortunately, they are among the most vulnerable ecosystems around the world. Their survival is mainly threatened by sea-level rise, wave erosion and human pressure. Halophytic vegetation distribution and dynamics control salt-marsh erosional and depositional patterns, critically determining marsh survival through complex bio-morphodynamic feedbacks. Although a number of studies have proposed species-classification methods and analyzed halophytic vegetation species distribution, our knowledge of the temporal evolution of species composition remains limited. To fill these gaps and better describe vegetation composition changes in time, we developed a novel classification method which is based on the Random Forest soft classification algorithm, and applied the method to two multi-spectral images of the San Felice marsh in the Venice lagoon (Italy) acquired in 2001 and 2019. The Random Forest soft classification achieves high accuracy (0.60 < R2 < 0.96) in the estimation of the fractional abundance of each species in both images. We also determined the local dominant species, i.e. the species with the highest fractional abundance in each pixel. Our observations on the dominant species in 2001 and 2019 show that: 1) the area dominated by Juncus and Spartina decreased dramatically in such period; 2) the area dominated by Limonium almost maintained constant; 3) a noticeable decrease in the bare-soil area occurred due to the encroachment of Salicornia between 2001 and 2019. We also noticed that the probability distribution of the dominant patch area of each species is consistent with a power-law distribution, with different slopes for different vegetation species at different times. We suggest that vegetation composition changes are related to sea-level rise and to the species-specific inundation tolerance.
The interplay between climate, sea-levels and erosion carved in Baltic rauks - complicated love story from Gotland
Authors: Strzelecki Mateusz C. , Duszyński Filip , Tyszkowski Sebastian , Zbucki Łukasz
Published: March 2021

Gotland and its sister island Faro are one of the hidden gems of Baltic Sea rocky coastal landscapes. The most intriguing, both in terms of morphology and evolution, landforms found along local coasts are rauks or raukars. Those limestone (remnants of Silurian reefs) stacks and pinnacles not only tower above present-day rocky shore platforms and beaches but also appear across numerous uplifted marine terraces and inland slopes. Rauks in often occur in groups or fields called raukfält. Surprisingly, those peculiar landforms have been to some extent neglected by geomorphologists and awaited in-depth study of their micro-relief and potential of the well-preserved marine notches to reconstruct past sea-level and environmental conditions operating on rocky coasts over the Holocene. It is important to note that marine notches are commonly treated as one of the best sea-level indicators, as they form close to the local tidal range.

In our paper, we present the results of the most recent mapping of raukars fields in key localities in northern Gotland and Faro including Langhammars, Digerhuvud, Gamla Hamn, Lergrav and Asundens. We measured the shape and elevation of marine notches above present-sea level using Terrestrial Laser Scanning and characterized the degree of weathering of rock surface of raukars bases and well-preserved notches using Schmidt hammer rock tests. In addition to morphometric and geotechnical tests, we monitored modern rates of downwearing of shore platform constitution base of rauks and tops of the local cliffs and rocky escarpments. We discuss the results of selected field surveys with well-established climatic reconstructions and the recently constructed Holocene shore displacement curves of Gotland. We hypothesize that the shape of detected notches not only indicate positions of former sea-levels but also could give us an insight into the differences in the efficiency of erosional and weathering processes operating on rauk surface (notch formation) during periods of different salinity and water temperature, characteristic for Holocene evolution of Baltic Sea.

This is the contribution to the National Science Centre in Poland project ‘RAUK- forgotten witness of Holocene sea-level changes and development of Baltic rocky coasts’ (UMO-2016/21/D/ST10/01976).
Greenworks:  Science, Role-Playing, and Community Transformation
Authors: Horodyskyj Lev , Lennon Tara
Published: March 2021

Environmental crises will overwhelmingly impact Millennials and Generation Z.  Most are aware of this reality and enthusiastic about finding and promoting community and policy solutions.  However, many youths also lack the communication and collaboration skills necessary to implement change in their communities.  The Greenworks program is a collaboration between Science Voices (a nonprofit focused on improving science education) and a political science course at Arizona State University (ASU).  Teachers and students from the University of the Virgin Islands (US), Khairun University (Indonesia), and University of Campinas (Brazil) are currently involved in on-going pilot projects as well.  The program provides space for students to practice deliberation and policy-making in an online role-playing game and then implement their own proposal to address an environmental problem in their community.

In the Greenworks program, students complete a short curriculum on geoscience and governance, engage in a role-playing diplomacy game to resolve environmental issues in a fictitious world, and then implement a community project to effect change in the real world.  ASU students participate as part of an online political science course formally offered by ASU.  Students and faculty mentors at other universities are recruited by Science Voices and complete custom curricula and community projects.  As part of the role-playing game that all students participate in, students are assigned to fictitious nations and address analogous real-world environmental and political challenges through diplomacy between nations with various competing objectives.  Challenges vary from semester to semester and include trade relations, climate change, plastic pollution, pandemics, and deforestation.  Through communication channels like Slack and Discord, students share their personal experiences on these topics and collaborate on related policy options.  Students enrolled through Science Voices also develop proposals to address local problems of importance and are provided with crowdfunded grants and materials to implement their proposal.

We will describe the program in more detail, discuss the experiences of our students, and the results of the first community projects.  We will additionally discuss developing this program as a collaborative space for students from the Global North and South to partner and co-mentor each other in developing local solutions to global challenges.
Planktic Foraminifera changes in the western Mediterranean Anthropocene
Authors: Pallacks Sven , Ziveri Patrizia , Martrat Belen , Mortyn Graham P. , Grelaud Michael , Schiebel Ralf , Incarbona Alessandro , Garcia-Orellana Jordi , Anglada-Ortiz Griselda
Published: March 2021

The increase in anthropogenic induced warming over the last two centuries is impacting marine environments. Marine planktic calcifying organisms interact sensitively to changes in sea surface temperatures (SST), and the food web structure. Here, we study two high resolution multicore records from two western Mediterranean Sea regions (Alboran and Balearic basins), areas highly affected by both natural climate change and anthropogenic warming. Cores cover the time interval from the Medieval Climate Anomaly (MCA) to present. Reconstructed SSTs are in good agreement with other results, tracing temperature changes through the Common Era, and show a clear 20th century warming signal. Both cores show opposite abundance fluctuations of planktic foraminiferal species (Globigerina bulloides, Globorotalia inflata and Globorotalia truncatulinoides) a common group of marine calcifying zooplankton. The abundance ratios between these species show the switch between winter / spring surface productivity and deep winter mixing in the Balearic basin. In the Alboran Sea, Globigerina bulloides and Globorotalia inflata instead respond to local upwelling dynamics. In the pre-industrial era, changes in planktic foraminiferal productivity and species composition can be explained mainly by the natural variability of North Atlantic Oscillation (NAO), and, to lesser extent, by the Atlantic Multidecadal Oscillation (AMO). In the industrial era, starting from about 1800 Common Era (CE), this variability is affected by anthropogenic surface warming, leading to enhanced vertical stratification of the upper water column, and resulting in a decrease of surface productivity at both sites. We found that natural planktic foraminiferal population dynamics in the western Mediterranean is already altered by enhanced anthropogenic impact in the industrial era, suggesting that in this region natural cycles and influences are being overprinted by human influences.
Fingerprinting Precipitation Processes in Remote-Sensing Observations
Authors: Barros Ana , Chavez Steven , Ji Lihui , Arulraj Malarvizhi
Published: March 2021

The distinctive fingerprints of precipitation processes in multifrequency measurements from GOES-East and GPM sensors are characterized using ground-based observations (rain gauges, disdrometers, spectrometers, radars, etc.) and microphysical-dynamical models.  The focus is on low-level warm rain processes, including the life-cycle of hydrometeors from CN activation until they reach the land surface, not resolved by numerical weather prediction models and missed by remote observing systems on the ground or satellites.  That is, the Terra Obscura of orographic precipitation. We propose and demonstrate a framework to infer local physical-statistical constraints from satellite measurements to improve quantitative precipitation estimates (QPE) in complex terrain regions globally.
An Agent-Based Approach for International Environmental Negotiations
Authors: Gazzotti Paolo , Castelletti Andrea , Tavoni Massimo
Published: March 2021

International Environmental Agreements (IEAs) on greenhouse-gases (GHG) emissions reductions have demonstrated to be extremely hard to achieve. Even after the Paris Agreement, global cooperation still may be cursed by free-riding threats and the risk of withdrawals, discouraging countries from increasing their voluntary commitment. 

Several studies have already addressed the problem of agreement stability, self-enforcing strategies and coalition formation. Most of them are supported by models grounded on game theory, which account for participation rationales and address research questions about coalition-formation and optimal transfer incentives. However, diplomacy on climate change is a considerably complex problem, not exhaustively tractable by any game-theoretical framework, as it combines several deep international issues. Historical disappointments (i.e., the COP15 in Copenhagen, 2009) as well as encouraging achievements (i.e., the Paris Agreement in 2015) have also demonstrated the importance of negotiation and interaction rules in facilitating common ground for cooperation. 

Here we present an attempt to reproduce and investigate IEAs on GHGs mitigation though an Agent-Based negotiating framework. It follows a bottom-up approach, based on the insights of complex systems theory,  by modelling the behaviour of each region-representative negotiator. Single agents generate and update their mitigation proposals accounting for personal multi-objective evaluations over potential upcoming scenarios informed by Integrated Assessment Models projections, reactions to other participants proposals, and private negotiation strategies. Few and simple interaction rules, shared as common-knowledge, regulate the negotiation process and guarantee termination and agreement, although not imposing any minimum participation level. Several negotiations follow one another on regular time intervals, allowing all participants to rediscuss and modify their commitment.

Preliminary results point out the importance of agents multi-objective evaluations, as the potential co-benefit estimated may foster personal participation and satisfaction from the agreement achieved. The high flexibility provided by this Agent-Based approach allows to easily vary and test several implementations and settings, searching for the best conditions to obtain cooperation as emerging behaviour in a complex yet realistic dynamic. 
RapidAI4EO: Advancing the State-of-the-Art in Continuous Land Monitoring
Authors: Marchisio Giovanni , Helber Patrick , Bischke Benjamin , Davis Tim , Wania Annett
Published: March 2021

New catalogues of nearly daily or even intraday temporal data will soon dominate the global archives. However, there has been little exploration of artificial intelligence (AI) techniques to leverage the high cadence that is already possible to achieve through the fusion of multiscale, multimodal sensors. Under the sponsorship of the European Union’s Horizon 2020 programme, RapidAI4EO will establish the foundations for the next generation of Copernicus Land Monitoring Service (CLMS) products. Focus is on the CORINE Land Cover programme, which is the flagship of CLMS. 

Specific objectives of the project are to: 1) explore and stimulate the development of new spatiotemporal monitoring applications based on the latest advances in AI and Deep Learning (DL); 2) demonstrate the fusion of Copernicus high resolution satellite imagery and third party very high resolution imagery; 3) provide intensified monitoring of Land Use and Land Cover, and Land Use change at a much higher level of detail and temporal cadence than it is possible today. 

Our strategy is two-fold. The first aspect involves developing vastly improved DL architectures to model the phenomenology inherent in high cadence observations with focus on disentangling phenology from structural change. The second involves providing critical training data to drive advancement in the Copernicus community and ecosystem well beyond the lifetime of this project. To this end we will create the most complete and dense spatiotemporal training sets ever, combining Sentinel-2 with daily, harmonized, cloud-free, gap filled, multispectral 3m time series resulting from fusion of open satellite data with Planet imagery at as many as 500,000 patch locations over Europe. The daily time series will span the entire year 2018, to coincide with the latest release of CORINE. We plan to open source these datasets for the benefit of the entire remote sensing community.

This talk focuses on the description of the datasets whose inspirations comes from the recently released EuroSAT (Helbert et al, 2019) and BigEarthNet corpora (Sumbul et al, 2019). The new corpora will look at the intersection of CORINE 2018 with all the countries in the EU, balancing relative country surface with relative LULC distribution and most notably adding the daily high resolution time series at all locations for the year 2018. Annotations will be based on the CORINE ontology. The higher spatial resolution will support modeling of more LC classes, while the added  temporal dimension should enable disambiguation of land covers across diverse climate zones, as well as an improved understanding of land use.

This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 101004356.