bluuebunny/crossref_metadata_2025 huggingface dataset:
Wind-Wave Energy Flux Measurements using Particle Image Velocimetry
Authors: Tenhaus Janina , Buckley Marc , Matt Silvia , Savelyev Ivan
Published: February 2023

Small-scale processes govern the transfer of energy and momentum at the coupled atmospheric and oceanic wave boundary layers. The physical wind energy input mechanisms by wave growth remain poorly understood (critical layer theory vs sheltering mechanism).We conducted laboratory velocity measurements within the first millimeters to centimeters above and below surface waves. A high resolution 2D Particle Image Velocimetry (PIV) system was installed in a wind-wave tunnel at a fetch of approximately 10 m. In addition, wave field properties were captured by Laser-Induced Fluorescence (LIF). Experiments were run with wind waves and wind over mechanical swell. During the measurements, 10-m wind speeds of 5 to 10 m/s were observed, with peak wave ages (cp/u*) ranging from 1 to 7.We will focus on the air phase and describe the modulations of the airflow structure. Furthermore, we will discuss the influence of peak wind-wave conditions (e.g., wave age, slope) on the dynamical role of the critical layer.
Aerosol source and processes in the Arctic
Authors: Du Mao , Shi Zongbo
Published: February 2023

Arctic earth system is highly sensitive environmental change. Arctic warms up by 2-4 times faster than the rest of the world. Environmental changes in Arctic has a profound impact on the regional and global climate. Aerosol particles play an important role in Arctic climate system. Predicting how Arctic atmosphere will change in a warming world requires a better understanding of the state of aerosols now, as a baseline from which any predictions can be made. Motivated by this, we carried out field observations in the Arctic region during a research cruise and at ground stations. The overall aim is to improve our understanding on the sources and aerosol particles and their impact on the climate and clouds.This presentation will show preliminary results from the DY151 research cruise (May-June 2022) to the Labrador Sea and the Davis Strait. The main objectives of the cruise include:Sources and processes of aerosol particles, cloud condensation nuclei and ice nuclei
Source and processes of gaseous pollutants
Formation and growth mechanism of new particles
Improve modelling of aerosol sources and processes in the Arctic and predict the impact of potential increase in Arctic shipping on the clouds and climate in the future
Operations onboard included the measurement of atmospheric and oceanic parameters, including:size distributions of particles from 1 nm to 20 µm;
gaseous pollutants such as volatile organic compounds, nitrogen oxides, HONO, HCHO, carbon monoxide, and sulphur dioxide;
molecular clusters and highly oxygenated organic compounds that contribute to the formation and growth of new particles;
chemical composition of aerosol particles including both organic tracers and inorganic species, and black carbon;
particle mass concentrations;
cloud condensation nuclei and ice nuclei concentrations;
optical observations of atmospheric particles and radiation; and
surface ocean chlorophyll a concentrations and routinely measured parameters onboard such as salinity.
These comprehensive observations will allow to better understand (1) the emissions, sources, and oxidation of key gaseous pollutants, (2) formation and growth of new particles, (3) contribution of newly formed particles to cloud condensation nuclei, and (4) sources of aerosol particles, cloud condensation nuclei and ice nuclei.
Effect of pH on pyruvic acid in bulk and at the air/liquid interface
Authors: Wank Veronika
Published: February 2023

Effect of pH on pyruvic acid in bulk and at the air/liquid interfaceVeronika Wank and Ellen H. G. BackusUniversity of Vienna, Faculty of Chemistry, Department of Physical Chemistry,Währinger Straße 42, 1090 Vienna, AustriaAbstract:Pyruvic acid, known as a relevant carboxylic acid for plant metabolic processes is also a contributor to the formation of secondary organic aerosols (SOA) and thus of great importance for the atmospheric cycle, especially in aerosols. At the interface, the behavior of relevant atmospheric molecules in aerosols is a major topic, as the surface is one of the first areas where chemical processes take place and thus determines the main reactivity of the aerosol. For acidic molecules, the acid/base behavior, especially at the interface, is relevant for understanding the chemical interaction of organic matter in atmospheric aerosols, where reaction rates and product distributions change due to different pH conditions, e.g. chemical processing and molecule transport.Since the pH of aqueous aerosols can vary widely, it is particularly important to understand changes in the surface structure due to the resulting (de)protonation reactions.This encourages us to take a closer look at the interfacial region of pyruvic acid in aqueous solution by using a complex surface-specific spectroscopic technique, so called sum frequency generation spectroscopy (SFG). For comparison, infrared bulk measurements utilizing ATR spectroscopy were completed. By combining ATR and SFG, the protonation state of pyruvic acid for bulk and interface was determined by probing the vibrational signatures of the carboxylic acid groups.Our results show that pyruvic acid at the water interface is more alkaline than in the bulk, which indicates that the carboxylic acid group deprotonates at a higher pH value at the surface than in the bulk. It is also evident from the SFG spectra that at lower pH the water molecules on the surface are displaced by PA molecules, whereas at higher pH the water molecules return to the surface and the PA molecules tend to go into the bulk.This implies that the protonation state of carboxylic acids like PA can thus affect the molecular orientation, conformation and function of molecules on aqueous surfaces, which likely has a significant impact on the chemical processes taking place at the aerosol surface in the atmosphere.
New constraints on the geodynamics of the Gulf of Aden from gravity field analysis
Authors: Marotta Anna Maria , Barzaghi Riccardo , Bollino Arcangela , Regorda Alessandro , Sabadini Roberto
Published: February 2023

We perform a new gravity analysis in the Gulf of Aden with the aim to find new constraints on the geodynamic evolution of the area. Our analysis is developed within the frame of the new GO_CONS_EGM_TIM_RL06 global gravity model solution (Brockmann et al., 2021) that reflects the Earth’s static gravity field as observed by GOCE (Gravity field and steady-state Ocean Circulation Explorer). We analyzed the solution at different harmonic degree, to account for different depths of the sources. Terrain correction has been performed by means of a spherical tesseroidal methodology (Marotta and Barzaghi, 2017) and the obtained residual gravity pattern has been compared to the gravity disturbance predicted by means of a 2D visco-plastic finite element thermo-mechanic model that simulates the evolution of the Gulf of Aden, from rifting to oceanization, for different crust thickness and initial thermal configuration of the lithosphere (Bollino et al., 2022). The formation of oceanic crust and serpentinite due to the hydration of the uprising mantle peridotite has been also accounted. To be compliant with the geodetic residual gravity, we define a model normal Earth in terms of a horizontally uniform density distribution that, vertically, coincides with the density distribution predicted at the sides of the 2D model domain at the same time of the comparison. In order to perform the comparison between observed and predicted gravity features, data have been extracted along six profiles crossing the Gulf of Aden at different sectors, from the south-east to the north west. Our preliminary results indicate that the Gulf of Aden developed as a slow passive rift of a hot lithosphere with a thick crust, fixing the upper bound of crustal thickness in the surrounding of the Gulf of Aden to 40 km.ReferencesBollino, A., Regorda, A., Sabadini, R., & Marotta, A. M. (2022). From rifting to oceanization in the Gulf of Aden: Insights from 2D numerical models. Tectonophysics, 838, 229483.Brockmann, J. M., Schubert, T., & Schuh, W. D. (2021). An improved model of the Earth’s static gravity field solely derived from reprocessed GOCE data. Surveys in Geophysics, 42(2), 277-316.Marotta, A. M., & Barzaghi, R. (2017). A new methodology to compute the gravitational contribution of a spherical tesseroid based on the analytical solution of a sector of a spherical zonal band. Journal of Geodesy, 91(10), 1207-1224.
Digital Twins of the Ocean – Opportunities to Inform Sustainable Ocean Governance
Authors: Kollert Joana , Visbeck Martin , Brönner Ute
Published: February 2023

Recent advances in High Performance Computing and Earth System Model resolution have enabled the Earth Science community to envision Digital Twins as an innovative approach to global environmental problems. This is also true of the Ocean Science community.
A Digital Twin of the Ocean (DTO) merges marine system models with observational data and machine learning analytics to produce a digital replica of the real ocean. In addition to natural phenomena, DTOs can include socio-economic factors (e.g. ocean-use, pollution). Thus, DTOs can be used to monitor the current ocean state, but also to simulate future ‘what-if’ scenarios for varying human interventions. Another benefit of DTOs is that they can be used by a variety of stakeholders: by scientists to understand the ocean, by policymakers to make well-informed decisions, and by citizens to improve ocean literacy. As such, DTOs are a powerful tool in future-proofing sustainable development. Moreover, they provide strong motivation to improve the marine data landscape and build an interoperable system with agreed upon formats and standards. DTOs are tailored to a specific ocean area or purpose, such that a DTO framework is needed to implement data connectivity and interoperability, ease of access, standards and to highlight gaps. The UN Ocean Decade Program DITTO aims to provide such a framework.  Specifically, DITTO advances worldwide collaboration between scientists, data and IT experts to develop a common understanding of DTOs, to establish best practices in their development, and to advance a digital framework for DTOs to empower ocean professionals from all sectors around the world to effectively create their own digital twins.
DTOs offer the technology for building a social-ecologically integrated ocean ecosystem with observation- and modelling networks that support sustainable ocean governance. 
UAV-based heterogeneity analysis of soil-plant-water system of small-plot experiment with different oat genotypes under Si and S foliar fertilization treatments
Authors: Budayné Bódi Erika , Kutasy Erika , Csajbók József , Acosta Santamaría Solange Paola , Magyar Tamás , Szőllősi Nikolett , Fehér Zsolt Zoltán , Nagy Péter Tamás , Nagy Attila , János Tamás
Published: February 2023

Five winter oat (Avena sativa L.) varieties were set in a small-plot field experiment to examine the abiotic stress considering silicone and sulphur foliar fertilization treatments under temperate and dry climatic conditions in Hungary. Numerous in situ and laboratory measurements were performed to describe the crop's condition at various phenological stages. Drones with multispectral, thermal and LiDAR payloads monitored the field both with high temporal and spatial resolution. A high level of GIS data assimilation was performed in order to handle the different spatial-related parameters in one interface. It is a multi-purpose experiment, and for all of them it is an important criterion whether the study was carried out in a truly homogeneous area. Practically, it means that we ignore the patterns of the crop or the soil. If this is not the case, the various parameters measured should be evaluated accordingly. Hence, our study's main goal here is to reveal the soil and crop heterogeneity level. For this, all the measured parameters are involved in the multi-parameter analysis by which the heterogeneity level of the site can be assessed.Practically, by this, we can answer the main question: is the field suitable to carry out analysis such as abiotic stress studies or yield prediction modelling on it or shall we handle certain parts differently?Based on the example of our experiment we design a workflow by which the heterogeneity level of a small-plot field can be assessed and provide a solution for how to handle it in order not to involve data which may mislead analysis.
Heat Waves over Eastern Balkans: A statistical analysis, possible causes and physical drivers.
Authors: Popov Hristo , Stepanyuk Oleg
Published: February 2023

Heat wave is a period of prolonged abnormally high surface temperatures relative to those normally expected. Heat waves may form when high pressure system strengthens and remains over a region from several days up to several weeks. Severe and exceptional heat waves, such as those that occurred over the Balkans (2007), France (2003), or Russia (2010), are associated with increased mortality, health hazards, reduced personal work productivity and have significant economic impacts by compromising agricultural harvest. Extremely high air temperature values in the Balkan Region are associated with anticyclones formed at the Azores maximum or high-pressure ridges and advections of hot air from the south and southwest.In our study we perform statistical analysis of the occurrence, durability and intensity of the heat waves over the Balkan Peninsula for the period 1980-2020 based on historical satellite and reanalysis datasets. We analyse correlation between heat waves occurrence and North Atlantic Oscillation Index and certain historical meteorological data for Atlantic and Mediterranean regions aiming to figure out possible causes and physical drivers of this phenomena. One of the mid-term goals of the project is to develop a CNN based predictive system for short and long-time forecasting of extreme weather conditions over the Balkans. 
A new filtering approach for multiple Doppler Lidar setups
Authors: Wolz Kevin , Holst Christopher , Beyrich Frank , Mauder Matthias
Published: February 2023

We compare the wind measurements of a virtual tower triple Doppler Lidar setup to those of a sonic anemometer located at a height of 90 m above ground on an instrumented tower and with those of a single Doppler Lidar. The instruments were set up at the boundary-layer field site of the German Meteorological Service (DWD) in July and August of 2020 during the FESST@MOL (Field Experiment on sub-mesoscale spatio-temporal variability at the Meteorological Observatory Lindenberg) 2020 campaign.  The triple Lidar setup was operated in a stare and in a step/stare mode at six heights between 90 and 500 m above ground, while the single Lidar was operated in a continuous scan Velocity-Azimuth-Display (VAD) mode with an azimuthal resolution of around 1.5 ° and a zenith angle of 55.5 °. Overall, both Lidar methods showed a good agreement for the whole study period for different averaging times and scan modes compared to the sonic anemometer. Additionally, we developed and show a new filtering approach based on a Median Absolute Deviation (MAD) filter for the virtual tower setup and compare it to a filtering approach based on a signal-to-noise ratio SNR threshold. The advantage of the MAD filter is that it is not based on a strict threshold but on the MAD of each 30-second period and can, therefore, better adapt to changing atmospheric conditions. In the comparison the MAD filter leads to a greater data availability while upholding similar comparability and bias values between the triple Lidar and sonic anemometer setups. Our results also show that a single Doppler Lidar is a viable method for measuring wind speed and direction with only small disadvantages, at least for measurement heights similar to our investigation and for comparable heterogeneous but flat landscapes.
Analyzing geological maps at the continental scale
Authors: Friedrich Anke M
Published: February 2023

Geological maps are essential products of geological work that display the results of generations of field geologists’ work. Most original geological maps are generated and utilized at local scales. At regional scales, geological maps have gained practical significance ever since William Smith’s 1815 geological map of England exemplified the robust nature of mapping and correlating strata beyond local scales. However, by comparison, geological maps compiled at continental scales appear to be of limited use outside of geological circles. They are often oversized, inhibiting their practical use, so they decorate our geoscience hallways and lecture halls with their beautiful colors and general esthetic appearance. Few outsiders can even read these maps. Their unique color-coding, the multiple non-diverging color schemes, and their complex legends further inhibit non-geologists from being able to recognize the enormous knowledge stored in these maps. I present an analysis of continent-scale geological maps by visualizing time not represented by the rock record (hiatus) and examining the dimensions of hiatal surfaces at interregional scales. The maps yield significant variability in sizes and space-time patterns of hiatal surfaces, a behavior expected in light of interregional-scale processes induced by both the plate and the plume mode of mantle convection. However, to rigorously test models of mantle convection, the temporal resolution of continent-scale maps must be increased to stages level, i.e., the temporal scale at which tectonic processes occur. In addition, synthesis of geological data on continent-scales requires the development and application of event-based stratigraphic-framework mapping.
Ozone impacts on tropical forest productivity
Authors: Sitch Stephen , Cheesman Alexander W , Brown Flossie , Artaxo Paulo , Cernusak Lucas A , Folberth Gerd , Hayes Felicity , Hill Tim , Mercado Lina , Uddling Johan
Published: February 2023

Tropospheric ozone (O3) reduces plant productivity by entering leaves, generating reactive oxygen species and causing oxidative stress which in turn increases respiration, decreases photosynthesis, plant growth, biomass accumulation, and consequently reduces the land carbon sink. Tropical forests are potentially most vulnerable to future O3 scenarios given their high productivity, generally high stomatal conductance and environmental conditions conducive to O3 uptake (eg precursor emissions during biomass burning).Here we present the first comprehensive set of measurements of O3 effects on plant physiology and biomass accumulation in tropical forests. We exposed twelve tropical tree species to elevated O3 concentrations in Open Top Chambers (OTCs) based at the James Cook University O3 experimental facility in Cairns, Australia, from which we generate O3 dose-response functions for each species. We test the importance of Leaf Mass per unit Area (LMA) as an indicator of O3 sensitivity.We use these relationships to parameterize the global land-surface model JULES, and apply the model over the pan-tropical region using contemporary near-surface O3 concentration fields. For the first time we quantify the impact of O3 on contemporary tropical productivity.
A globally distributed dataset using generalized DL for rapid landslide mapping on HR satellite imagery
Authors: Catani Filippo , Meena Sansar Raj , Nava Lorenzo , Bhuyan Kushanav , Puliero Silvia , Pedrosa Soares Lucas , Dias Helen Cristina , Floris Mario
Published: February 2023

Multiple landslide events occur often across the world which have the potential to cause significant harm to both human life and property. Although a substantial amount of research has been conducted to address the mapping of landslides using Earth Observation (EO) data, several gaps and uncertainties remain when developing models to be operational at the global scale. To address this issue, we present the HR-GLDD, a high-resolution (HR) dataset for landslide mapping composed of landslide instances from ten different physiographical regions globally: South and South-East Asia, East Asia, South America, and Central America. The dataset contains five rainfall triggered and five earthquake-triggered multiple landslide events that occurred in varying geomorphological and topographical regions. HR-GLDD is one of the first datasets for landslide detection generated by high-resolution satellite imagery which can be useful for applications in artificial intelligence for landslide segmentation and detection studies. Five state-of-the-art deep learning models were used to test the transferability and robustness of the HR-GLDD. Moreover, two recent landslide events were used for testing the performance and usability of the dataset to comment on the detection of newly occurring significant landslide events. The deep learning models showed similar results for testing the HR-GLDD in individual test sites thereby indicating the robustness of the dataset for such purposes. The HR-GLDD can be accessed open access and it has the potential to calibrate and develop models to produce reliable inventories using high-resolution satellite imagery after the occurrence of new significant landslide events. The HR-GLDD will be updated regularly by integrating data from new landslide events.
Tephrochronology and geochemical correlation of Middle Pleistocene distal tephra deposits in Armenia
Authors: Grigoryan Edmond , Meliksetian Khachatur , Gevorgyan Hripsime , Savov Ivan , Navasardyan Gevorg , Bangoyan Marina , Boyakhchyan Tatevik
Published: February 2023

Widespread volcanism played significant role in geological history of Anatolian-Armenian-Iranian orogenic plateau formed as a result of continental collision of Arabian and Eurasia. Among diverse chemical compositions and eruption styles, reported for volcanoes of Armenian highlands, noteworthy are distal tephra fallout deposits and voluminous ignimbrite shields resulted from violent explosive volcanic eruptions with VEI estimations ranging form 4 to 6. Obviously, such eruptions had significant impact on climate, human occupation and migrations in the entire region and provide insights to volcanic hazards in the region.  One difﬁculty in the identifying and studying explosive eruptions during Pleistocene, is that many tephra fallout deposits are not preserved in the geologic records, since unconsolidated deposits erode rapidly, particularly in mountain topography. In Armenia, there is a sparse geologic record of tephra fallouts, except where these deposits are preserved beneath pyroclastic ﬂows, which presumably occurred very soon after tephra deposition. Such tephra deposits, are known in Armenia in underlying ignimbrite units related to activity of Aragats stratovolcano (Gevorgyan et al., 2018), beneath Ani ignimbrite in western part of Armenia and activity of Irind and Pemzashen volcanoes. Alternatively, tephra deposits can be preserved if layers are rapidly covered by loess deposits or colluvium deposits or landslides shortly after the eruption and tephra deposition occurs. Such conditions are known for distal tephra fall deposits from Ararat volcano in Ararat depression and in NE Armenia near Ijevan. A big number of finds of  Paleolithic stone tools, and resent achievements in studying Paleolithic archeology in south Caucasus region provide evidences of early human occupation in the territory of south Caucasus.  This contribution  aims to fill gaps in our knowledge of distal tephra layers identified in Armenia, namely in  north-east, south and central parts of Armenia.  New data based on detailed geochemical investigations and 40Ar/39Ar age determinations of distal tephra layers originated from violent explosive eruptions, reported in this study, can contribute to establish chronostratigraphic horizons as marker layers for paleoclimate and archaeological records during Middle-Upper Pleistocene in the entire region. Tephra layers preserved in Pleistocene sedimentary sequences in Armenia provide important information about these violent explosive eruptions that are significant for the geological evolution and the human geography of the entire region.
The outcome of plant-microbial competition for N in a wheat system and the implications for yield and N2O mitigation
Authors: Keane James Benjamin , Lee Sarah , McNamara Niall , Whitaker Jeanette , Moir James , Levy Pete , Robinson Sam , Linnekogel Stella , Walker Hannah , Storer Kate , Berry Pete , Bentley Mark , Howarth Steve , Toet Sylvia
Published: February 2023

Nitrous oxide (N2O) is a potent greenhouse gas (GHG) with a global warming potential 265 times that of carbon dioxide (CO2) over 100 years. Contributing approximately 70% of global anthropogenic N2O emissions, agriculture represents the largest area of uncertainty for GHG reporting and the most challenging sector for emissions reduction: global N2O emissions are increasing at double the rate estimated by the Intergovernmental Panel on Climate Change (IPCC). The largest source of agricultural N2O emissions is from application of inorganic-N fertilisers, the manufacture of which produces more than 1% of global CO2 emissions and consumes 1% of global energy output.However, typical crop N uptake efficiency (NupE) means approximately half the fertiliser doesn’t reach the target plant, causing further ecological problems, such as biodiversity loss from eutrophication and atmospheric deposition. The extent to which microbial immobilisation of fertiliser N contributes to the NupE value of ca. 60% is currently unknown. If N immobilisation is found to be a large contributor to reducing N available to crops, this offers new opportunities to better manage fertiliser N inputs. Critically, with a growing global population, it is vital that we can increase food crop yields, and more efficient use of water and nutrients could help close the 70% ‘yield gap’ between potential and actual crop yields. Finally, inorganic N is the largest single cost in gross margins for wheat production and prices are rising. Increased NupE therefore represents a key opportunity for farmers to increase their financial sustainability.  We hypothesised that under the conventional management of three applications of inorganic N in the spring, crops do not have the ability to outcompete the fast-growing soil microbial community for N, and that by supplying N to the crop in a ‘little and often’ approach, we could increase NupE by reducing immobilisation, and consequentially reduce N2O emissions. We conducted a field study of a winter wheat crop on a northern UK farm to investigate this, which compared conventional N fertiliser management (220 kg N ha-1 over three applications) of ammonium nitrate, to a little and often approach (220 kg N ha-1 over six applications) and an untreated (0 kg N ha-1) control. We followed the crop until harvest, and continuously measured N2O emissions and net ecosystem exchange of CO2 using a skyline2D automated flux system and also measured C and N pools in soil, plants and microbial biomass to assess changes in N uptake and allocation.We will present data which shows the outcome of plant-microbe competition for N in our agricultural system, and discuss the implications of different N fertiliser management for yield, profitability and GHG mitigation.
Hazard assessment for gas emission and flank landslides at Albano crater lake (Rome)
Authors: Ranaldi Massimo , Carapezza Maria Luisa , Fabbri Andrea , Liotta Marcello , Patera Antonio , Pizzino Luca , Tarchini Luca
Published: February 2023

Repeated flooding episodes occurred from the crater lake of Albano until 398 B.C. These floods were probably caused by sudden injection of gas and warm waters on the lake bottom, or also by the overturn of the lake which would have brought to the surface the deep water rich in CO2. Since several years, we have been monitoring the crater lake chemical composition as well as its physico-chemical parameters and dissolved gas content, in order to assess evidences of possible deep fluid input in the lake water. The concentration of dissolved gases, and their isotopic composition (d13CTDIC, 3He/4He) suggest the presence of deep gases (CO2 and CH4) within the lake bottom layer. However, the total pressure of dissolved gases is presently, at any depth, much lower than the hydrostatic pressure. If, for any reason, a significant volume of deep water should rise to the surface, only limited phenomena of gas exsolution are to be expected. A density variation of shallow lake water due to cooling, in case of heavy rainfall in harsh winters (T<8.5°C), may produce water overturns. Such phenomena, as long as they happen with a certain frequency, would prevent the accumulation of dangerous quantities of CO2 in the deepest lake water strata. Apart from a volcanic unrest, the most dangerous condition is the occurrence of seismic swarms with hypocentres in the Lake Albano area, which could lead to an increase in the influx of hot gases and fluids in the lake. Currently, the conditions for a rapid release of significant quantities of CO2 from Lake Albano do not exist. To improve the knowledge of the Lake Albano  water circulation, we investigated also the isotopic 87Sr/86Sr composition of the lake water, comparing the results with those of the rocks hosting the aquifers. Results indicate that Lake Albano water samples well fit a binary mixing of a high 87Sr/86Sr ratios end-member (Colli Albani volcanites) and a low ratio end-member (carbonate basement) in a proportion of 75% and 25% respectively. Moreover, the landslide hazard of the internal slopes of Lake Albano has been assessed using Ordinary Least Squares and Empirical Likehood Ratio modelling functions. The presence of numerous dwellings and recreational activities along the internal slopes of the crater lake, makes the area of potentially-high risk, both because of the inner intense slope instability and for possible secondary effects due to tsunami waves that might be generated by the impact of sliding subaerial masses on the lake surface or by sub-aqueous landslides.
Soil structure – a dynamic soil property which effects multiple soil functions
Authors: Leuther Frederic
Published: February 2023

Soil structure is a dynamic property of soils, which refers to temporal changes in the spatial arrangement of pores, organic matter, and minerals. As for many chemical reactions, also soil structure can be at a state of dynamic equilibrium, in which bulk properties, such as macroporosity, average pore size, and others apparently remain constant even though pores are formed and destroyed continuously. On the long term, the creation and destruction of structural properties are in balance as long environmental conditions, such as climate or cover crops, do not change or no external disturbances, such as tillage, become effective.The irreversible redistribution of soil constituents, i.e. soil structure turnover, itself determines essential soil functions. For example, the creation and disruption of a pore network affects water flow, water storage, and aeration. Microsites of higher densities limit the accessibility of plant residues and organic amendments for microbiology through pores, and in consequence, increase the capacity of soil to store organic carbon. However, so far there are only few experiments trying to capture these dynamic processes and quantify the contribution of different drivers. Using examples describing the relationship between soil structure and soil functions at different sites, I will show that there is a need for new long-term monitoring experiments to capture these dynamics at temporal resolution.
Towards a high-resolution MAR-NEMO coupling to explore atmosphere-ocean-ice interactions in the Arctic
Authors: Lambin Clara , Kittel Christoph , Fettweis Xavier
Published: February 2023

Arctic changes are at the centre of climate concerns. Notably, recent Arctic warming drives rapid sea ice decline making the Arctic increasingly vulnerable. To better anticipate the consequences of this strong Arctic warming, it is crucial to better understand the driving processes responsible for large uncertainties in future climate projections. Interactions at the atmosphere-ocean-sea ice interface require particular attention. In this context, the PolarRES project aims at developing the coupled system MAR (atmosphere) - NEMO (ocean-sea ice) over the Arctic region at high spatial resolution (25 km). Such coupling will enable the climate community to access precise data at large scale. Since this coupling has never been applied to the Arctic, a proper model evaluation is required. Here standalone model simulations are compared against a newly compiled dataset including land station and buoys data. We find high correlations between the modelled and observed data. Our evaluation marks an important step in in the ongoing development of coupled models.
Albedo effects on the SeaWIFS4OLCI algorithm
Authors: Dermann Diana , Popp Thomas
Published: February 2023

The SeaWIFS4OLCI / SeaWIFS4MERIS algorithm retrieves the Aerosol Optical Depth (AOD) on a global scale. Strong overestimations of AOD have been observed for this algorithm in areas with high albedo.

Currently the algorithm works on a surface albedo database calculated from the MERIS data of 2008. For the calculation all observed reflectances of 2008 are taken into consideration depending on their scattering angle. By searching for minimum reflectances within a 10-day window the effects of aerosol as well as cloud shadows are avoided. The results are then compared to Look-Up-Tables for aerosol-free radiative transfer to retrieve the estimated surface albedo.

In this study, albedo variations between the years 2008 and 2018 are compared using a newly computed surface database for 2018. Then the AOD for 2018 using the albedo database for 2008 and 2018 is calculated. To validate the results, the retrieved AOD of both years are compared to data from AERONET Stations.

It is expected that the update of the surface database will contribute strongly to the improvement of the SeaWIFS4OLCI / SeaWIFS4MERIS algorithm and ultimately the time-consuming albedo calculation needs to be conducted for each separate year.
Optimization of Water-Energy-Carbon Nexus in Urban Residential Water Uses for Shanghai, China
Authors: Zhou Jianyu , Zhu Tingju
Published: February 2023

Urban residential water uses entail energy consumption and associated carbon emissions. Reducing residential water uses thus can simultaneously save water and energy and help reduce carbon emissions. However, residential water uses are strongly affected by the choices of household appliances and fixtures, and water use behaviors. In this study, we first conducted a household water use survey in Shanghai, the largest city in China, to understand residential water use behaviors in different seasons. A two-stage stochastic optimization model is developed to optimize water and energy conservation decisions so as to minimize the expected total cost of water and water-related energy uses and maximize carbon emission reduction. Data collected through questionnaire surveys are used to parameterize the optimization model. Water and energy conservation choices are categorized into long- and short-term decisions. The results show that in Shanghai residential water uses has a strong impact on urban carbon emission reduction. Typical temperature range in different seasons strongly affects the effectiveness of short-term conservation actions. The results support a subsidy policy for water-saving appliances that can incentivize citizens in water-saving. Model results are useful for exploring the water-energy-carbon nexus of urban households considering seasonal factors
Future characteristics of tropical cyclones over CORDEX East Asia domain in Multi-RCMs under the SSP scenarios
Authors: Kim Eunji , Kim Taehyung , Mun Taeho , Shin Seok-Woo , Lee Minkyu , Cha Dong-Hyun , Chang Eun-Chul , Ahn Joong-Bae , Min Seung-Ki , Kim Jin Wook , Byun Young Hwa
Published: February 2023

Tropical cyclones (TCs), which often form over the western North Pacific (WNP), have a large socioeconomic impact and result in destructive damages in East Asian countries. Therefore, it is critical to estimate future changes in TCs characteristics under the global warming. In this study, future characteristics of TCs using five regional climate models (RCMs) (i.g., RegCM4, GRIMs, WRF, CCLM, and HadGEM3-RA) were investigated in Coordinated Regional Climate Downscaling Experiment (CORDEX) East Asia domain. Five RCMs were forced by the UK Earth System Model (UKESM) under the historical and two Shared Socioeconomic Pathways (SSP) scenarios (SSP1-2.6 and SSP5-8.5). The simulation experiments were conducted at about 25-km horizontal resolution. The multi-RCM ensemble mean was used for analysis to reduce the uncertainty of a single RCM. In the historical period (1985-2014) during the TC season (June-November), the ensembled RCMs properly reproduced the TC genesis over the WNP comparable to the best track data. In the future climate, the RCMs tended to migrate the core region of TCs genesis more northward compared in the present climate. This migration could be related to weakening of vertical wind shear over the mid-latitudes, due to decreased meridional sea surface temperature gradient.
Biogeography of Larches in North-East Siberia - using Single Nucleotide Polymorphisms derived by Genotyping by Sequencing
Authors: Haupt Sarah , Meucci Stefano , Herzschuh Ulrike , Harpke Dörte , Bernhardt Nadine , Killing Stefanie , Pestryakova Luidmila A. , Zakharov Evgenii S. , Kruse Stefan
Published: February 2023

The present distribution pattern of Siberian boreal forests that are dominated by larches is to an unknown extent influenced by the glacial history. Here, we investigated whether we can observe patterns in the genetic variability of Siberian larches (Larix spp.) that can help us to unravel biogeographic migration routes since the Last Glacial Maximum (LGM). We revealed the spatial distribution of 14,003 Single Nucleotide Polymorphisms (SNPs) derived by Genotyping by Sequencing (GBS) in a subset of 148 larch individuals with a cluster analysis. To shed light on Larix’ postglacial migration routes, we applied an Approximate Bayesian Computation (using the software DIYABC). The results of the cluster analysis revealed the presence of three to four statistically verified clusters from Western to Eastern Eurasia that match well to the already expected distinction into the main larch species Larix sibirica, L. gmelinii and L. cajanderi. It can be discussed that under the light of ecological aspects and the spatial assignment to geographic regions, six clusters are plausible instead of the statistically derived most probable optimum of three to four main clusters. The tested hypotheses in DIYABC show that all present existing populations seem to be initiated far before the LGM. We presume that the different populations originate from larch populations that survived the glacial periods. Having the complex terrain in mind, we deduce that those individuals rather survived in refugia in the North, than migrated through complete recolonization from the South. The northernmost expansion during the Holocene seems to have benefitted from refugial populations ahead of the treeline, which explains the existence of Larix in the Far North although the treeline migration rates were slow. From our results, we expect that the present migration is probably slow at first, as there are currently no refugial populations far north, as there were probably in Holocene. But in the future, isolated trees in the tundra could become a starting point for rapid dispersal of boreal forests in the course of current climate warming.
Where will the Norwegian wind power go? Comparison of generation and transmission expansion scenarios.
Authors: Roithner Maximilian , Price James , Schmidt Johannes , Zeyringer Marianne
Published: February 2023

The Norwegian electricity demand has been almost entirely (~95 %) met by hydropower (~140 TWh of annual production, ~30GW of installed generation capacity), and low power prices were predominant for years. This has led to the development of industry and consumer dependence on ubiquitous cheap energy. The energy price shock in 2022 elevated price levels and opens multiple possible futures. With rising demand to be expected through electrification, increases in wind power generation capacity have been discussed and at least onshore been met with scepticism, and acceptance issues. As the export of energy in the form of oil and gas has been a major source of income for Norway that is now sought to be replaced, additional stakes join the discussion. Ideas of energy intensive industry such as battery production or data centres which would rely on low electricity prices, while also bringing demand increases, have been expressed. The future path splits between (further) integration into the European power system and (more) isolation of the Norwegian system. This would be expressed through electricity transmission and generation equipment expansion, which are important measures to ensure the adequacy and low carbon intensity of future nation- or continent-wide power systems. Policies may be measured by different competing targets, such as national price levels (which if low are favourable for industry), transnational carbon intensity (which if low helps to reach climate targets) or cross-border electricity trade (which if high helps to balance the system and generates income for the exporter).  We explore those trade-offs with Norway as a case study. The technical potential for North Sea offshore wind generation expansion is evident, and policy targets to expand offshore wind generation to the level of current hydropower generation (the highest in Europe) exist. Yet, the expansion of subsea transmission capacities (which would allow for more balancing through the Norwegian hydro reservoirs) seems to be on hold. Using the expansion and dispatch optimizing power system model highRES, we present scenarios for different degrees of expansion of offshore wind generation and (mostly subsea) transmission, to illustrate the crossroads in Norwegian energy policy, whose outcome could impact the European system.
Evaluation of nine years of continuous δ13CO2 measurements in Heidelberg, Germany
Authors: Cranton William , Eckhardt Henrik , Hoheisel Antje , Schmidt Martina
Published: February 2023

Measurements of atmospheric CO2 mole fraction in combination with δ13CO2 contain additional information on the CO2 source mixture at a measurement station. Instrumental developments, such as cavity ring-down spectroscopy (CRDS), have facilitated the conduction of continuous in-situ measurements of CO2 mole fraction and δ13CO2 with a high temporal resolution. This has enabled a robust and detailed local time series to be established at an urban station in Heidelberg in south-western Germany, where a CRDS G2201-i analyser has been used to measure the CO2 mole fraction and 13C/12C ratio from 2014 to 2023. This nine year time series is analysed for seasonal variations and trends in regional and local CO2 sources. We applied different approaches based on the Keeling/Miller-Tans method to identify δ13CO2 source signatures within the Heidelberg catchment area. Doing this gave δ13CO2 source values that were less depleted in the summer and more depleted in the winter, indicating a stronger biogenic effect in summer and stronger fossil fuel contributions in winter.
The reduction of heating and cooling CO2 emissions with the ATES triplet
Authors: van Esch Matthijs S. , Bloemendal Martin , Hartog Niels , Vardon Philip J.
Published: February 2023

Low temperature Aquifer Thermal Energy Storage (ATES) is increasingly used for space heating and cooling. Though these systems emit 3-4 times less CO2 compared to gas heating, they still require a substantial amount of electricity, mostly because of the heat pump (~60%). Storing higher temperatures (HT) to be used for direct heating can be a solution to circumvent the use of a heat pump, however the return temperature after heating is not usually cold enough to use directly for cooling. The first HT ATES systems that are implemented have either no cooling, or alternative means for cooling. With better insulated buildings, that require both heating and cooling, as well as an increased pressure on the electricity grid, an autarkic system is needed that can supply both heating and cooling. The ATES Triplet system aims to do just that.Similar to and HT ATES system, the ATES Triplet stores hot water at supply temperature needed for space heating in a hot well. Unlike the HT-ATES system, it also aims to store water at the supply temperature for cooling in a cold well. This heat and cold can be harvested by solar collectors and dry coolers (or other green heat/cold sources locally available). After the water extracted from the wells is used to heat/cool the building, the solar collectors and dry coolers can be used to store water at the right temperatures. However, the availability of these sources can be insufficient to reach the required temperatures. A third well is added that functions as a buffer. Water used for heating or cooling can be stored here until there is enough heating/cooling capacity available from the solar collectors and dry coolers to upgrade the water to the required temperature, and store in the hot or cold well. Furthermore, the solar collectors and dry coolers can also be used for direct space heating and cooling, making the entire system and autarkic heating and cooling system.Initial simulations show a substantial reduction to operational CO2 emissions compared to conventional heating systems. Though a higher initial investment is required, systems also show an increased economic performance over conventional ATES systems and gas heating. Further research will investigate the effect of subsurface conditions, system layout and other operational conditions on the economic and environmental performance of the system.
Exploring Cenozoic vegetation cover and paleobiodiversity evolution induced by paleogeography and climate change
Authors: Tardif Delphine , Sepulchre Pierre , Condamine Fabien , Thomas Couvreur
Published: February 2023

Paleogeographic evolution is a major forcing of climate on long (multi-million years) time scales, which in turn can drive important vegetation cover variations. While recent studies have shown the important role played by abiotic factors on species diversification and on the establishment of modern biodiversity gradients, and although climate models are designed to simulate increasingly realistic vegetation cover, it remains difficult to estimate the accuracy of the results obtained. Indeed, the fossil record available to estimate the evolution of the paleovegetation cover remains heterogenous and fragmentary in some regions.  Here, we present climate and vegetation cover response to paleogeography evolution throughout the Cenozoic as simulated with IPSL-CM5A2 Earth System Model. In a second time, we wish to explore means of using temperature and precipitation values extracted from such models simulations, in order to constrain birth-death diversification models. While the use of regionally-averaged abiotic parameters seems a potentially considerable improvement, as opposed to current methods based on global climate curve temperature, this methodology presents some technical challenges that remain to be tackled.