bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical choices in Large-Eddy Simulations influence their ability to represent shallow convective organisation
Authors: Janssens Martin , Glassmeier Franziska , Siebesma A. Pier , R. de Roode Stephan , C. van Heerwaarden Chiel , Vilà-Guerau de Arellano Jordi
Published: March 2022

A growing body of evidence suggests that shallow circulations play a key role in organising trade-wind clouds at the mesoscales. In turn, many of these mesoscale circulations appear to emerge directly from the shallow convection itself. We infer a very simple model for explaining this feedback from Large-Eddy Simulations of a classical numerical experiment with minimal physics (BOMEX), which depends only on the turbulent transport of liquid water in cumulus clouds and the mean environment. Since the dominant scales of the cumulus convection driving the organisation are constrained around a kilometer, we hypothesise that simulations of the development of mesoscale cloud patterns through this mechanism are sensitive to choices in the numerical representation of the cumulus convection. We show that the timescale over which mesoscale cloud structures develop can more than double in our model, merely by modifying its grid spacing or advection schemes. Hence, rather high resolutions (<100m) or significantly improved unresolved scales models may be required to faithfully represent certain forms of trade-wind mesoscale cloud patterns in models, and to understand their influence on the cloud feedback more accurately.
Distributed Acoustic Sensing in the Athens Metropolitan Area: Preliminary Results
Authors: Smolinski Krystyna T. , Bowden Daniel C. , Lentas Konstantinos , Melis Nikolaos S. , Simos Christos , Bogris Adonis , Simos Iraklis , Nikas Thomas , Fichtner Andreas
Published: March 2022

Once a niche technology, Distributed Acoustic Sensing (DAS) has gained increasing popularity over the last decade, due to its versatility and ability to capture extremely dense seismic datasets in a wide range of challenging environments. While DAS has been utilised in some particularly remote locations, such as on glaciers and volcanoes, it also holds a great deal of potential closer to home; beneath our cities. As DAS is able to be used with existing telecommunication fibres, urban areas contain huge potential networks of strain or strain-rate sensors, right beneath our feet. This data enables us to monitor the local environment, recording events such as earthquakes, as well as characterising and monitoring the shallow subsurface. DAS experiments using dark fibres are unintrusive and highly repeatable, meaning that this method is ideal for long-term site monitoring.

In collaboration with the OTE Group (the largest telecommunications company in Greece), we have collected urban DAS data beneath North-East Athens, utilising existing, in-situ telecommunication fibres. This large dataset contains a wide range of anthropogenic signals, as well as many seismic events, ranging from small, local events, to an internationally reported Magnitude 6.4 earthquake in Crete.

We conduct a preliminary analysis of the dataset, identifying and assessing the earthquake signals recorded. This will be compared with the event catalogue of the local, regional network in Athens, to determine our sensitivity to events of different magnitudes, and in a range of locations. We hope to gain an understanding of how DAS could be combined with the existing network for seismic monitoring and earthquake detection.

Moving forward, we aim to also apply ambient noise methods to this dataset in order to extract dispersion measurements, and ultimately invert for a shallow velocity model of the suburbs of Athens.
N2O-emission risk assessment tool for nitrogenous fertilizer applications
Authors: Vestergaard Poulsen Henrik , Bruun Sander , Skov Nielsen Cecilie , Kolind Hvid Søren
Published: March 2022

Nitrous oxide (N2O) emitted from agricultural soils makes up a significant part of the collective agricultural greenhouse gas (GHG) emissions. These emission are to a large extent caused directly or indirectly by the application of nitrogenous fertilizer and there is a strong demand for mitigation strategies.

 

Nitrous oxide is produced in the soil in a range of different processes but mainly in microbial nitrification and denitrification. A number of factors exert influence on these microbial processes in the soil, most notably the oxygen concentration, availability of ammonium and nitrate, available organic matter and diffusivity, and fairly advanced process-based simulation models are often used in attempts to simulate the amount of N2O emitted. Here we propose using more a simplistic modelling approach to provide a novel risk assessment tool for nitrogenous fertilizer applications to be implemented in Danish farmers field management programmes.

 

At SEGES Innovation we have unique database access to field activity data from Danish farmers - e.g. crop sequence, fertilizer applications, residue handling, soil texture - covering more than 85 % of the Danish cultivated area. Based on these data and field specific climate data, a soil water balance model (Plauborg et al. 1995) and soil organic carbon model (Taghizadeh-Toosi et al. 2014) are running in daily timesteps for all fields in the database. These models provide, respectively, the daily level of WFPS in the soil and the organic matter turnover rate in the soil simulated during the weather forecast period of 10 days. Those two outputs are combined with a simulated soil temperature in a simplified version of the NGAS-model (Parton et al. 1996) to give a rough simulated N2O-emission for any planned fertilizer application throughout the weather forecast period.

 

The risk assessment tool exhibits this daily simulated N2O-emission as a risk evaluation of fertilizer application to the farmer in field management programmes, where future field activities are entered and logged. The objective is to lower the GHG emission by reducing the number of fertilizer applications right at peak N2O-emission conditions, once the farmers are presented with this information.    
Unraveling energy balance partitioning in sub-alpine forests: interplay of canopy structure, topography, and meteorological conditions
Authors: Mazzotti Giulia , Webster Clare , Quéno Louis , Cluzet Bertrand , Essery Richard , Jonas Tobias
Published: March 2022

In Alpine regions, forests that overlap with seasonal snow mostly reside in complex terrain. Due to major observational challenges in these environments, the combined impact of forest structure and topography on seasonal snow cover dynamics is still poorly understood. However, recent advances in forest snow process representation and increasing availability of detailed canopy structure datasets now allow for hyper-resolution (<5 m) snow model simulations capable of resolving tree-scale processes. These simulations can shed light on the complex process interactions that govern forest snow cover dynamics.

We present multi-year simulations at 2 m resolution obtained with FSM2, a mass- and energy-balance based forest snow model specifically developed and validated for meter-scale applications. Our 3km2 model domain encompasses forested slopes of a sub-alpine valley in the Eastern Swiss Alps. Simulations thus span a wide range of canopy structures, terrain characteristics, and meteorological conditions typical for the region. We analyze spatial and temporal variations in forest snow energy balance partitioning, aiming to quantify and understand the contribution of individual energy exchange processes at different locations and times.

Our results suggest that snow cover evolution is equally affected by fine-scale canopy structure, terrain characteristics and meteorological conditions. We show that the interaction of these three factors can lead to snow distribution and melt patterns that vary between years. Generally, we find higher snow distribution variability and complexity in slopes that receive solar radiation early in winter. Our process-level insights corroborate and complement existing empirical findings that are largely based on snow distribution datasets only. Hyper-resolution simulations as presented here will thus help us to better understand how ecohydrological regimes sub-alpine regions may evolve as a result of forest disturbances and a warming climate.
Impact of Ocean Warming and Natural Variability on the Stratification and Mixed Layer Depth around Iceland
Authors: Ruiz-Angulo Angel , Portela Esther , Perez-Hernandez Maria Dolores , Ólafsdóttir Solveig Rosa , Macrander Andreas , Meunier Thomas , Jonsson Steingrimur
Published: March 2022

The ocean around Iceland witnesses some of the most important transformations of water masses that drive the Global Ocean Circulation. Here, we analyze 28 years of continuous four-yearly hydrographic sections around Iceland from 1990 to 2018. The water-mass properties around Iceland show important spatial variability. From their temperature, salinity and stratification structure, we classified the Icelandic waters in three distinct regions with similar characteristics: the Southwest, the North and Northeast regions. The warm and salty Atlantic Waters that dominate the Southwest show the deepest winter mixed layer (~500m) while the North and Northeast have relatively shallow (< 100m) to moderate (~100m) winter mixed layer depth.  
Based on the decomposition of the total stratification into temperature and salt contributions, we find that the subsurface summer stratification is mainly dominated by temperature except for the North and Northwest regions where salinity dominates. 

The interannual variability of the mixed layer and its water properties is also large around Iceland. Mixed layer waters were generally colder in the 90's, then warmed until approximately 2015, and became colder again from 2015 to 2018.  Except for the southwestern region, the observed interannual variability seems unrelated with the North Atlantic Oscillation, and its main forcing remains an open question to address in future studies. Only in the northeastern region a multidecadal mixed layer warming trend clearly emerges from the interannual variability. This is associated with the Atlantification of the Arctic, which is also observed from the northward displacements of the isotherms derived from satellite SST. Elsewhere, rather than clear trends, we observe changes in the structure of the mixed layer temperature and salinity that compensate in density.  The present study provides an unprecedented and detailed regional description of the seasonal to decadal variability of the mixed layer depth and the stratification, and their link with the changing North Atlantic under global warming.
Global glacier evolution over the last millennium and the influence of climate forcings on the mass balance
Authors: Vlug Anouk , Marzeion Ben , Prange Matthias , Maussion Fabien
Published: March 2022

Mass loss of glaciers and ice caps has been one of the major contributors to sea-level rise over the past century. Glaciers respond slowly to a changing climate. Therefore, glacier evolution over the past century is partly a result of prior changes in the climate, resulting both from internal variability in the climate system and changes in external forcings. Here we present a simulation of global glacier evolution over the period 850-2000 CE and assess the influence that different climate forcings have on the glacier mass balance. The glacier evolution simulation thus serves as a base for the mass balance attribution experiment.

The Open Global Glacier Model (OGGM) was used to simulate glacier geometry and mass balance evolution of land-terminating glaciers. The dynamic simulations were forced with the full length of the Last Millennium Reanalysis (LMR), a climate timeseries covering the period 0-2000 CE, using the first part for spin-up only. The initialization of the glacier states in 850 CE was done with a calibration procedure, making use of glaciers with a relatively short memory for initializing those with a longer one.

To assess the influence of different climate forcings (volcanic, greenhouse gases (GHG), orbital, land cover and land use, solar and anthropogenic ozone and aerosols) on glacier mass balance, simulations of the Community Earth System Model Last Millennium Ensemble (CESM-LME) are being used. The CESM-LME fully forced, single forced and 850 CE control simulations are used to force OGGM in climatic mass balance simulations. In those simulations the glacier geometries are prescribed with those from the LMR forced dynamic simulation, in order to avoid biases in the attribution caused by deviating glacier evolutions under the different forcings.

Results show that the changes in the GHG forcing have little influence on the SMB from 850 to ~1850 CE. After that the influence becomes increasingly more negative. All other forcings that have been assessed here have positive contribution to glacier mass balance over the last millennium. Although the influence of land use and land cover change has not received a lot of attention before in this context, it has a substantial influence on global glacier mass in our simulations. However, the influence of the forcings differs strongly between regions.
Does the Natural DIC Affect the Storage of Total Inorganic Carbon in the Central Labrador Sea?
Authors: Raimondi Lorenza , Tanhua Toste , Azetsu-Scott Kumiko , Wallace Doug
Published: March 2022

The Labrador Sea plays a central role in the oceanic storage of carbon. In particular, several studies have shown that this region has amongst the highest integrated column inventories of anthropogenic carbon (Cant) in the world’s ocean. The rate at which Cant is stored in this region appears to be connected to changes in ocean circulation and can therefore vary over time. Nevertheless, it is still unclear whether the temporal variability of the total Dissolved Inorganic Carbon (DIC) inventory is solely due to the changes in Cant concentrations or whether there is a contribution of the natural component of DIC to this signal.

The Bedford Institute of Oceanography has been maintaining the Atlantic Zone Off-Shore Monitoring Program (AZOMP) in the Labrador Sea since the early 1990s. The AZOMP involves annual occupations of the AR7W line that crosses the Labrador Sea and includes sampling of DIC, as well as multiple transient tracers such as CFC-12 and SF6.  

By using observations of DIC along the AR7W line, as well as previous estimates of Cant obtained with transient tracers (using a refined version of the Transit Time Distribution method; TTD) and new estimates of Cant based on the extended Multiple Linear Regression (eMLR) method, we provide a first insight on the role that the natural component of DIC plays in the temporal variability of inorganic carbon in the central Labrador Sea between 1993 and 2016.

We show that different methods to estimate Cant can lead to different conclusions on the role of the natural variability of DIC and that these discrepancies could be related to the assumptions implied in the Cant estimation methods. In particular an analysis of Cant estimates obtained with our refined version of the TTD method in different water masses, highlighted that further refinement of the tracers’ saturation assumption could be necessary in this region. This refinement could reconcile the Cant estimates from the two methods and therefore lead to an unambiguous role of the natural DIC in this region.
Use of blended evidence sources to build a history of flooding impact and an impact severity scale: A case study of Nairobi, Kenya
Authors: S. Majani Bernard , D Malamud Bruce , Millington James
Published: March 2022

Many urban areas in the Global South are often data-poor and lacking in longer-term records of the occurrence and impact of natural hazards. Here we explore a methodology for using blended evidence sources to build a history of flooding impacts, along with a hazard severity scale, in Nairobi, Kenya, from 1978 to 2018. The evidence we use to build our Nairobi Flood Impact Database includes existing digital flood databases, newspapers, radio/TV broadcasts, government and NGO reports, peer-review journal articles, insurance company and emergency service records, online website reports, blogs, Google Analytic records and 330 photos/video from social media sources. For each record, we systematically extract from the source material, available information on the flood’s location, timing, and impact, with impact broken up into human (7 subcategories, e.g., fatalities), infrastructure (18 subcategories, e.g., building damage) and environment (6 subcategories, e.g., trees fallen). The resultant Flood Impact database has 1495 entries, which when entries that refer to the same flood event are grouped, result in a total of 354 flood events for 1978 to 2018 (41 years) in Nairobi, a much more extensive record than available previously. The flood database has the largest number of records for 2011 to 2018, given the increased use of social media and newspapers to report flood event impacts in recent years. We also see a peak in the years 1996 to 2000 (when there was a particularly heavy amount of rain due to El Niño) and then again 2016 to 2018. We then develop a five-point Likert scale for evaluating the adequacy of evidence types for recording location, timing and impact of floods. Finally, using a combination of existing impact-related natural hazard scales from the literature and our database, we build a five-part flood severity index combining the different types of impact, ranging from minor to catastrophic floods. Each of the impact types (31 subcategories) from our impact database is given a weighting from which inform this five-point severity index and map this severity index onto selected flood events from our Nairobi Flood Impact Database. Our database was then examined for temporal and spatial clustering in Nairobi and compared to different types of urban built up areas within Nairobi. This research provides a methodology and extensive blended database of the impact of floods over a 41-year period in a data poor area, providing a resource for better understanding the past history of spatial temporal hazard patterns, which can then be further expanded as to the causes, impact and how the flood events were dealt with in terms of recovery, lessons learnt and ways of mitigation and resilience building.
3D GNSS Velocity Field sheds light on the Deformation Mechanisms in Europe:  effects of the vertical crustal motion on the distribution of seismicity
Authors: Socquet Anne , Piña Valdes Jesus , Beauval Céline , Doin Marie Pierre , D'Agostino Nicola , Shen Zhengkang
Published: March 2022

Crustal deformation and seismicity in Europe are still poorly understood. Seismic activity is classically ascribed to crustal strain rates generated by tectonic deformation. However, crustal deformation is not only due to tectonic loading, but can also be related to isostatic and buoyancy processes that induce additional strains on the crust by flexure. The influence that those processes have on seismic activity, as well their interaction, is still controversial, and the main limitation to study it is because the deformation processes are commonly analyzed separately in small regions. We present here a 3D secular velocity field that covers Eurasia and its plate boundaries including 4508 GNSS stations obtained by combining 10 different datasets. We have developed a method based on spatial filtering to identify outliers and smooth the velocity field, and have computed a strain rate map representative of the main deformation processes that affect Europe. The vertical and horizontal deformation features were compared with earthquake recurrence models obtained from the spatial and temporal distribution of the seismicity in Europe. Our results suggest that is not possible to explain the seismicity of Europe based on the horizontal strain rate maps only. In some areas markers of the crustal flexure such as the vertical velocity field and its derivative, may help to interpret earthquake distribution models derived from geodetic data.
New cosmogenic nuclide dating laboratory in CENIEH, Spain
Authors: Fujioka Toshiyuki , Miguens Leticia , Iglesias Javier , Jiménez Fernando , Sarró María Isabel , Parés Josep María
Published: March 2022

Centro Nacional de Investigación sobre la Evolución Humana (or National Research Centre on Human Evolution, CENIEH) is located in Burgos, northern Spain. The centre is dedicated to human evolution research worldwide, including Atapuerca, a world heritage archaeological site where the oldest human fossil in Europe to date have been discovered. To support the needs of characterising geological and sedimentological context of archaeological sites, the institute also features a wide range of geological analysis (e.g., Laser diffraction grain size analyser, XRD, XRF, Raman Spectroscopy, SEM, Micro CT, Digital mapping and 3D analysis) and geochronology laboratories (including palaeomagnetism, OSL, ESR and U-series). In 2020, a new cosmogenic nuclide dating research line has initiated to strengthen the existing geochronological capabilities in the centre, particularly, at timescales of early-mid Pleistocene and beyond. To date, we have established a procedure for routine quartz separation and 10Be-26Al extraction. Current projects include 10Be-26Al burial/isochron dating of cave deposits, fluvial terraces and artefacts in the context of archaeological and landscape evolution research. In this paper, we present a general setup of the laboratory, its capacity and current projects as well as future prospective.
Dynamics in Marine Protected Areas in the German Bight (North Sea) under different forcing scenarios
Authors: Rubinetti Sara , Fofonova Vera , Androsov Alexey , Kuznetsov Ivan , Rick Johannes Josef , Mielck Finn , Sander Lasse , Wiltshire Karen Helen
Published: March 2022

This study is dedicated to the dynamics in Marine Protected Areas (MPAs) in the German Bight under different forcing scenarios. A large amount of data has been collected in the North Sea over the last decades to characterize MPAs, which can shed light on long-term changes in the North Sea dynamics from abiotic part to ecosystem. At the moment, a question is raised about the interconnection between MPAs and their representativeness for the larger area. Nowadays, this issue can be resolved with the existing numerical instruments and accumulated observations. We paid particular attention to the tidal dynamics in the North Sea since tidal residual circulation and asymmetric tidal cycles significantly define circulation patterns, transport and accumulation of biogeochemical material, and the distribution of bedforms in this relatively shallow region. We analyzed in detail the tidal energy transformation and the role of higher harmonics in the domain. The tidal ellipses, maximum tidally induced velocities, energy fluxes and residual circulation maps are constructed and analyzed. The numerical tool used in this study is the FESOM-C model (Androsov et al., 2019), which works with triangular, rectangular or mixed grids and is equipped with a wetting/drying option. A grid with a resolution of up to 10 meters in the flooded areas is used.

Androsov, A., Fofonova, V., Kuznetsov, I., Danilov, S., Rakowsky, N., Harig, S., Brix, H., and Wiltshire, K. H.: FESOM-C v.2: coastal dynamics on hybrid unstructured meshes, Geoscientific Model Development, 12, 1009-1028, 10.5194/gmd-12-1009-2019, 2019.

 
Advancing Socio-Hydrology Through the Development of High Impact Learning Courses, Engaging Students and the Community (Costa Rica)
Authors: Castillo M. Rene , Nunez Judy
Published: March 2022

The human-environmental system composed of both social and biophysical aspects requires scientists in the field of hydrology to develop an understanding of both aspects for research when working in relation to people. Students are the future in research, characterized as the leaders of tomorrow yet many geoscience undergraduates lack experience outside of the classroom before entering research where people are directly impacted. Using experiences that connect students to local communities, allowing them the opportunity to be emerged in not just fieldwork but community components can stimulate advancements within socio-hydrological at a more sustainable level. This high impact learning experience addresses the challenges of the world water crisis in the context of socio-hydrology and implementation of scientific projects that improve water security in San Jose, Costa Rica. Coupling a global NGO with hydrology, here we outline a method and quantify the outcome of the course for engaging both students and the community as utilized within Costa Rica, combining the scientific components of research and the community involvement.
Attribution of the fall 2021 extreme precipitation event over Italian region of Liguria 
Authors: Di Sante Fabio , Pichelli Emanuela , Coppola Erika , Vautard Robert , Scussolini Paolo , Soubeyroux Jean-Michel , Dubuisson Brigitte
Published: March 2022

Climate change exhibits one of its strongest and shocking effects through extreme precipitation events. Extreme convective precipitation events are getting more intense and more frequent and their attribution to global warming is confirmed by recent studies in many regions of the world. During October the 4th and 5th a Nord-Atlantic trough entering the western Mediterranean favored the formation of deep convective systems feeded by the wet and warm prefrontal flow. One of them built up over the Ligurian Gulf on the 4th. Sustained by long-lasting interaction of large scale conditions and local forcings, the V-shape storm persisted over 24 hours locally accumulating more than 900 mm of rain. The event exceeded local and European precipitation records and caused landslides and flash-floods. In this study we try to objectively link the event to climate change through an extreme value theory analysis. This has been carried out through rain-gauge observations over Liguria, available continuously from 1960 for the fall season. The climate conditions of the event are compared to a pre-industrial period 1.2°C cooler than the present days. The Euro-CORDEX 12km resolution ensemble has been also used to confirm the event attribution to global warming. 
Insights into stakeholder perceptions of Impact -based Forecasting (IbF) and implications for operational implementation in hydrometerology 
Authors: Robbins Joanne , Bee Emma , Sneddon Alison , Amuron Irene , Stephens Elisabeth , Brown Sarah
Published: March 2022

Impact based Forecasting (IbF) represents a shift away from traditional hazard focussed hydrometeorological forecasts and warnings (e.g. wind gusts exceeding 80mph at a location and time), towards those that communicate the risk, as a function of probability of the hazard occurring and its consequence(s) or impact on society. To achieve this shift, there is recognition that the exposure and vulnerability of society to the hazard, need to be considered in addition to hazard forecasts. The methods by which these additional variables are integrated to provide IbF outputs varies, but there has been limited research to understand why this is the case and what implications this has for operational IbF services.

To understand the variation in perceptions around IbF and the possible consequences these perceptions may have for operational implementation, this work invited practitioners, forecasters and researchers, working within the NERC and FCDO Science for Humanitarian Emergencies and Resilience (SHEAR) Programme, to provide their perspectives on a range of IbF related topics. Semi structured interviews were conducted with individuals that were selected by the project team based on their experience and expertise regarding IbF. A total of 11 interviews were held with stakeholders from the UK, South Africa, Uganda, Kenya, India, and Nepal, with representation from international institutions and NGOs, research institutes and hydrometeorological agencies.  

Our research aimed to answer the following questions: (1) Is there a shared understanding of what IbF is and means across individuals involved in its development? (2) Is there a shared perception of the challenges, barriers and opportunities associated with implementing IbF operationally? In this session, we illustrate areas of consensus and clarity, as well as areas of divergence, and knowledge gaps that could impede effective collaboration and implementation. We review the relevance of our findings for researchers and practitioners and explore how this might inform IbF activities in the future. 
Tackling the challenge between lab- and field-based detection of floating plastics using hyperspectral remote sensing
Authors: Tasseron Paolo , Schreyers Louise , Peller Joseph , Biermann Lauren , van Emmerik Tim
Published: March 2022

Plastic pollution in aquatic ecosystems has increased dramatically in the last five decades, with strong impacts on human and aquatic life. Recent studies endorse the need for innovative approaches to monitor the presence, abundance, and types of plastic in these ecosystems. One such approach gaining rapid traction in the remote sensing community is the use of hyperspectral cameras to identify floating plastic litter. However, most experiments using this approach have been conducted in controlled laboratory environments, making findings exceptionally challenging to apply in natural environments. We present a method that links lab- and field-based identification of macroplastics using hyperspectral data (1150-1675 nm). Two experiments using riverbank-harvested macroplastics were set up in (1) a laboratory environment, and (2) at the Rhine River. The reflectance characteristics of the sample items were analysed to understand the influences of the two environmental settings. Eleven lab-based images (n = 786.264 pixels) and two field-based images (n = 40.289 pixels) were used for these analyses. Next, multiple classifier algorithms such as support vector machines (SVM), spectral angle mappers (SAM) and spectral information divergence (SID) techniques were applied, because of their robustness to varying light intensities and high accuracies in mapping spectral similarities. Our results showed that SAM classifiers are most robust in separating plastic debris from natural or human-made background elements, such as vegetation, quay walls, and sand. By applying lab-based spectral data for plastic detection in our field-based images, we were able to attain user accuracies up to 93.6% (n = 8.370 plastic pixels) using SAM. The same approach resulted in accuracies of 50.2% and 65.4% for SID and SIDSAM, respectively. The limitations of this study concern the low number of images used for training and classification, hardware issues related to the hyperspectral camera, and the unforeseen dynamic nature of environmental conditions outside a laboratory. Nevertheless, this study provides key fundamental insights in linking lab-based data to plastic detection in the field. In doing so, a contribution to the development of future spectral missions to monitor plastic pollution in aquatic ecosystems is made.
The impact of CAMS prognostic aerosols on temperature forecast with the ECMWF weather forecast model
Authors: Flemming Johannes , Remy Samuel , Hogan Robin , Huijnen Vincent , Haiden Thomas , Kipling Zak , Parrington Mark , Inness Antje , Garrigues Sebastien
Published: March 2022

The Copernicus Atmosphere Monitoring Service (CAMS) produces operationally global 5-day forecast of atmospheric composition and the weather using ECMWF’s Integrated Forecasting System (IFS) since 2015.Beginning with a system upgrade in June 2018 (45r1), the ozone and aerosol fields have been used in the radiation scheme to account for their radiative impact in the global CAMS forecasts. This approach replaced an aerosol and ozone climatology, which had been used before and which is still used in ECMWF's operational high-resolution medium-range NWP forecasts. The CAMS forecast system, which runs at a resolution of about 40 km, is applied here as a test-bed to explore the importance of aerosol direct feedback in an operational configuration, which can guide developments on composition-weather feedbacks for ECMWF's medium-range, monthly and seasonal forecasts. The CAMS prognostic aerosol simulations and the assimilation of different AOD retrievals (MODIS, VIIRS, S5P) have been substantially further modified in several upgrades of the CAMS operational system since 2018.

We will discuss the changes and improvements of temperature forecast errors focusing on the impact of changing the aerosol simulation and AOD assimilation in the recent cycles. These changes were introduced to improve the realism of the aerosol forecasts, which is a key CAMS forecast product, and not developed specifically considering their impact on NWP.

We will show NWP scores, evaluation with synop-observations and satellite radiation products to demonstrate the impact of the prognostic aerosols. We will also compare the results of the NWP forecast of the CAMS suite, with the NWP scores of ECMWF high resolution forecast run ay 9 km spatial resolution globally. We will further demonstrate that the consistent updates of both the climatological and prognostic aerosol fields are an important prerequisite for a sound assessment of the importance of prognostic aerosol in NWP applications.
Analysis of Soil and Water Conservation Benefit of Conservation Reserve Program
Authors: Zhou Ruipeng , Yang Qi
Published: March 2022

Abstract: The Conservation Reserve Program (CRP) in the United States has been implemented for 35 years. The analysis and evaluation of its soil and water conservation benefits can provide experience and reference for the construction of China's the Grain for Green Project. Changes in CRP area and soil and water conservation benefits were analyzed based on CRP-related data obtained from the USDA Farm Service website and erosion rate data from the 2017 National Inventory Summary Report. From 1986 to 2020, the land area participating in CRP showed a bimodal change, with the largest area in 2007 reaching 1.498 million km2. The largest area of land types involved is Cropland, accounting for about 93%, and the largest area after the transfer of CRP is also Cropland, which is about 59%. During 2006-2017, soil, nitrogen and phosphorus reduction losses were 2318.28 million tons, 3.20 million tons and 0.64 million tons, respectively. When the CRP area reached 12 thousand km2, the soil, nitrogen and phosphorus sequestration no longer increased with the increase of the abandoned Cropland. There is a positive linear relationship between carbon dioxide absorption and CRP participation area, and the cumulative fixed CO2 amount from 2006 to 2017 is about 504 million tons. The U.S. land fallow protection project has significant soil and water conservation benefits, reducing soil erosion, nitrogen and phosphorus loss, and playing an important role in improving the ecological environment.

Key word: Conservation Reserve Program; soil loss; nitrogen; phosphorus; Carbon dioxide
Phase field viscoelastic fracture models for ice sheet dynamics
Authors: Stocek Jakub , Arthern Robert , Marsh Oliver
Published: March 2022

Antarctic ice sheets grounded under the sea level can break apart if the ice cliffs at the edge of ice shelves collapse under their own weight. The process is known as the marine ice cliff instability and could lead to a rapid retreat of ice shelves, acceleration of the ice sheets, and subsequent increase in global sea levels.
A classical treatment of fracture by Griffith [3] introduced the energy release rate for brittle elastic materials, the energy required for crack propagation, and created the energetic fracture criterion. Unfortunately such theories are insufficient as they cannot reproduce curvilinear cracks, kinks, crack branching, crack arrest, or crack nucleation. One can overcome issues of the classical Griffith theory with a diffusive crack modelling by variational approaches based on energy minimisation [1, 4].
In this talk we present a thermodynamically consistent phase field viscoelastic fracture models relevant for ice sheet dynamics that allows to incorporate additional rheological properties such as creep. By identifying the relevant free energy and dissipation potential functions of interest one can derive relevant viscoelastic models. In the case of Maxwell rheology with Glen's flow law [2], one arrives at two possible systems, one better suited for short timescales and another for longer timescales.
We present robust adaptive numerical schemes that allow to treat both compressible and incompressible materials with pure Dirichlet or Neumann, as well as mixed boundary conditions. 
Computational experiments demonstrate the robustness of the numerical solvers and importance of inclusion of fracture mechanisms into ice sheet models.

[1] B. Bourdin, G.A. Francfort, J.J. Marigo, Numerical experiments in revisited brittle fracture. Journal of the Mechanics and Physics of Solids, Vol. 48, pp. 797--826, 2000.
[2] J.W. Glen, The creep of polycrystalline ice. Proceedings of the Royal Society London A, Vol. 228, pp. 519--538, 1955.
[3] A.A. Grifﬁth, The phenomena of rupture and ﬂow in solids. Philosophical Transactions of the Royal Society London A, Vol. 221, pp. 163--198, 1921.
[4] C. Miehe, F. Welschinger, and M. Hofacker, Thermodynamically consistent phase‐field models of fracture: Variational principles and multi‐field FE implementations. International journal for numerical methods in engineering, Vol. 83, pp. 1273--1311, 2010.
Monitoring lake ice with seismic and acoustic sensors
Authors: Schmelzbach Cedric , May Daniel , Wetter Christoph , Stähler Simon , Clinton John
Published: March 2022

Seismic monitoring of the thickness and elastic parameters of floating ice on lakes and the sea is of interest in understanding the climate change impact on Alpine and Arctic environments, assessing ice safety for recreational and engineering purposes, studying ice shelves as well as exploring possibilities for the future exploration of the icy crusts of ocean worlds in our solar system. Seismic data can provide an alternative to remote-sensing and ground-based radar measurements for estimation of ice thickness in cases where radar techniques fail. Because of the difficult access to Alpine and Arctic environments as well as seismic sensor coupling issues in ice environments, it is of interest to optimize the use of seismic instruments in terms of sensor type, sensor numbers and layouts.

With the motivation to monitor over time the seismic activity of the lake ice and the ice properties, we conducted a series of seismic experiments on frozen lake St. Moritz in the Swiss Alps during two consecutive winters. Arrangements of sensors ranging in numbers from 96 geophones in mini-arrays to installations of 8, 2 and 1 conventional seismic sensors were used to measure the seismic wavefield generated by ice quakes (cryoseisms), artificial sources like hammer strokes, and ambient vibrations. These data provide an impressive and rich insights into the growth of the ice and variations of seismic activity with time. Even recordings with only a single station enable the determination of ice parameters and location of ice seismicity. Furthermore, we are exploring the value of recording air-coupled waves with microphones as alternative contact-free measurements related to seismic wave propagation in the ice, possibly even with sensors placed on the lake shore.
COVID-19 waves: intrinsic and extrinsic spatio-temporal dynamics over Italy
Authors: Alberti Tommaso , Faranda Davide
Published: March 2022

COVID-19 waves, mostly due to variants, still require timely efforts from governments based on real-time forecasts of the epidemics via dynamical and statistical models. Nevertheless, less attention has been paid in investigating and characterizing the intrinsic and extrinsic spatio-temporal dynamics of the epidemic spread. The large amount of data, both in terms of data points and observables, allows us to perform a detailed characteristic of the epidemic waves and their relation with different sources as testing capabilities, vaccination policies, and restriction measures.

By taking as a case-study the epidemic evolution of COVID-19 across Italian regions we perform the Hilbert-Huang Transform (HHT) analysis to investigate its spatio-temporal dynamics. We identified a similar number of temporal components within all Italian regions that can be linked to both intrisic and extrinsic source mechanisms as the efficiency of restriction measures, testing strategies and performances, and vaccination policies. We also identified mutual scale-dependent relations within different regions, thus suggesting an additional source mechanisms related to the delayed spread of the epidemics due to travels and movements of people. Our results are also extremely helpful for providing long term extrapolation of epidemics counts by taking into account both the intrinsically and the extrinsically non-linear nature of the underlying dynamics. 
Risk Profiles of Impactful and Extreme Hydrological Events for Alpine Reservoirs
Authors: Milojevic Tatjana , Blanchet Juliette , Lehning Michael
Published: March 2022

Climate change impacts in the Swiss Alps have been seen through changes in the hydrologic regime. These include glacier mass loss, shifts in peak snowmelt and changes in seasonal precipitation type and timing (e.g., more rain-on-snow events in winter). In addition, it is expected that global warming will lead to more intense extreme rainfall events in the Alps in the future. Combined, all of these changes pose a challenge to planning, management and optimization for hydropower producers operating in the Alpine region. In particular, because the impacts are not expected to be felt homogeneously across the region, it is difficult to ascertain how the risks will differ between individual reservoirs without more localized assessment. This study focuses on the use of statistical tools that are specifically adapted for application to small datasets (such as the extended generalized pareto distribution), in order to calculate return periods of extreme precipitation and high reservoir inflow events for individual Alpine reservoirs. In addition, we show how the return periods of persistent low inflow periods (droughts), which have the potential for significant negative impacts on hydropower production, are determined using extreme value theory. The result is effectively a risk profile comprised of return periods for both extreme high precipitation/inflow and impactful low precipitation/inflow events that can be used by researchers and practitioners alike to further understanding of local climate change risks to individual reservoirs.
UAV based thermal imaging at the leaf scale – A case study in a tropical dry forest
Authors: Gerchow Malkin , Kühnhammer Kathrin , Iraheta Alberto , Beyer Matthias
Published: March 2022

Leaf and canopy temperature have long been recognized as an important indicators of plant water status. Recently, unmanned aerial vehicles (UAVs) became arguably the superior platform to acquire leaf temperatures due to their low cost and high spatiotemporal resolution and flexibility compared to satellite platforms. However, when interested in absolute leaf temperatures of individual leaves, the resolution of thermal cameras is often not sufficient and UAV overflight height needs to be adjusted. This causes heterogeneous forests to become inherently complex structures with great challenges for generating thermal orthomosaics. In addition, currently applied uncooled thermal sensors are affected by their ambient conditions causing temperature readings to drift during flight operation.
To address these issues, we employed a dual camera setup consisting of a visible and thermal sensor to aid the geometric calibration of the thermal sensor. To account for the temperature drift, we developed an alternative flight planning approach: During the UAV mapping mission ground temperature references are repeatedly captured from above forest clearings to estimate temperature drift and continuously adjust temperature calibration. We compare our temperature calibration approach to the default camera calibration and to a simple pre- and post-flight calibration method under different atmospheric conditions (temperature, wind and cloud coverage). The geometric accuracy of the forests thermal orthomosaics is validated against ground control points.
Accurate calibrated canopy temperatures will allow to compare canopy temperature differences while also providing uncertainty estimates of the temperature data. High resolution thermal maps at the forest leaf scale will open up the possibility to analyze plant water status during seasonal dry forest changes.
Prediction of Subsurface Fluid Flow via Physics Informed Neural Networks
Authors: Walter Linus , Parisio Francesco , Vilarrasa Víctor
Published: March 2022

Geoenergies such as underground gas storage and energy storage, geothermal energy and geologic carbon storage are key technologies on the way to the foreseeable energy transition. The reservoir characterization in these projects remains challenging since predictive modeling approaches face limitations in identifying the spatial distribution of distinct lithologies and their hydro-mechanical properties from downwell testing procedures. Pumping tests are usually carried out to infer permeability, but offer only few observation points in space and require large extrapolation through inversion. The application of Physics Informed Neural Networks (PINN) offers a promising solution which can seamlessly incorporate field data, while enforcing the accordance with physical laws in the domain of study. This concept is implemented via two distinct loss terms for both the physical constraints and for the observational data in the loss function of an Artificial Neural Network (ANN). The physics-informed loss term contains a mass balance equation consisting of a storage and a diffusion component. The process is considered to be purely hydraulic and Darcy flow is assumed. The observational loss term compares the output of the ANN to a set of training data. This set consists of  the system’s initial fluid pressure, as well as of a fluid pressure time series at the domain boundaries and at the borehole location. Preliminary results suggest that our PINN model is able to forecast the spatiotemporal fluid pressure distribution in a 2D domain for a variety of pumping test schemes. In this way, we give a first impression of the opportunities that PINN applications offer in the field of reservoir modeling.