bluuebunny/crossref_metadata_2025 huggingface dataset:
Effectiveness of Satellite-based Vegetation Index for Simulating Watershed Response Using an LSTM-based model in a Distributed Framework
Authors: Lee Jeonghun , Kim Dongkyun
Published: February 2023

This study developed a distributed hydrologic model based on Long Short-Term Memory (LSTM) to predict flow discharge of Joongrang stream located in a highly urbanized area in Seoul, Korea. The model inputs are the time series of 10-minute radar-gauge composite precipitation data at 239 grid cells (1km2) in the watershed and the Normalized Difference Vegetation Index (NDVI) data derived from Landsat 8 images and the model output is the 10-minute flow discharge at the watershed outlet as output. The model was trained for the calibration period of 2013-2016 and was validated for the period of 2017-2019. The NSE value over the validation period corresponding to the optimal model architecture (256 LSTM hidden layers) with and without NDVI input data was 0.68 and 0.52, respectively, which suggests that the machine can learn dynamic processes of soil infiltration and plant interception from the remotely sensed information provided by satellite.This work was supported by the National Research Foundation of Korea(NRF) grant funded by the Korea government(MSIT) (No. NRF-2022R1A4A3032838). 
Deep volatile reservoirs in super-Earths and sub-Neptunes
Authors: Dorn Caroline
Published: February 2023

There is a lot of enthusiasm in the exoplanet community for the detection and characterization of super-Earth and sub-Neptunes. These planets seem most abundant among observable planets, and yet we know little about their interiors. Indirect evidence implies that sub-Neptunes have thick H/He envelopes on top of massive magma oceans, while super-Earths have lost their H/He envelopes. There is a lack of similar planets in the Solar System and therefore their origin and atmospheric evolution represent an important challenge for our understanding of planets.Moreover, the majority of current formation and evolution models suffer from simplified assumptions of chemically inert interiors and cold rocky interiors in solid-state, as well as the neglect of volatile-exchange at the rock-atmosphere interface. This prevailing view is shifting: (1) the majority of exoplanets are partly molten, i.e., they host global magma oceans; (2) redox reactions between magma and atmospheric volatiles affect bulk composition; and (3) magma oceans represent huge reservoirs for volatiles. The exoplanet community is just beginning to explore new dimensions of these complexities. I will give an overview of general and personal efforts on this front.
An appraisal using magnetic data of the Continent to Ocean Transition Structure West of Iberia
Authors: Neres Marta , R. Ranero César
Published: February 2023

The conceptual models of magma-poor rifted margins are greatly influenced by the continent-to-ocean transition structure of the archetypal magma-poor West Iberia Margin. Some previous works with West Iberia magnetic data have been used to constrain the structure and interpret the transition from the exhumed mantle domain to the oceanic crust formed at a spreading center. However, it is found that the resolution uncertainty of the geophysical data was generally overlooked, leading to over-detailed interpretations. In this work we use synthetic magnetic modelling to show that magnetic data acquired at sea-level cannot resolve sub-horizontal lithological layering in deep-water continental margins. Then, we present a new magnetic model guided by a refined velocity model of the wide-angle seismic IAM-9 profile in the Iberia Abyssal Plain. This new model supports that the J-anomaly is caused by a ~6 km thick oceanic crustal structure with locally increased magnetization compared to regular oceanic crust. This J-anomaly crust abuts the exhumed mantle across a nearly vertical boundary, and is the oldest accreted oceanic crust. These results support that mantle exhumation was abruptly terminated by the accretion of oceanic crust. Mantle melting creating oceanic crust was probably not driven by gradual lithospheric thinning and asthenospheric upwelling, but may be the result of seafloor spreading center propagation cutting across the lithosphere and creating the abrupt structure.This work was funded by the Portuguese Fundação para a Ciência e a Tecnologia (FCT) I.P./MCTES through national funds (PIDDAC) – UIDB/50019/2020- IDL. Support from FCT (PTDC/CTA-GEF/1666/2020), Spanish Ministry of Science and Innovation (CTM2015-71766-R, PID2019-109559RB-I00) and Spanish Research Agency (CEX2019-000928-S) is also acknowledged.
Deep learning-based generation of 3D cloud structures from geostationary satellite data
Authors: Brüning Sarah , Niebler Stefan , Tost Holger
Published: February 2023

Clouds and their interdependent feedback mechanisms remain a source of insecurity in climate science. This said, overcoming relating obstacles especially in the context of a changing climate emphasizes the need for a reliable database today more than ever. While passive remote sensing sensors provide continuous observations of the cloud top, they lack vital information on subjacent levels. Here, active instruments can deliver valuable insights to fill this gap in knowledge.This study sets on to combine the benefits of both instrument types. It aims (1) to reconstruct the vertical distribution of volumetric radar data along the cloud column and (2) to interpolate the resultant 3D cloud structure to the satellite’s full disk by applying a contemporary Deep-Learning approach. Input data was derived by an automated spatio-temporally matching between high-resoluted satellite channels and the overflight of the radar. These samples display the physical predictors that were fed into the network to reconstruct the cloud vertical distribution on each of the radar’s height levels along the whole domain. Data from the entire year 2017 was used to integrate seasonal variations into the modeling routine.The results demonstrate not only the network’s ability to reconstruct the cloud column along the radar track but also to interpolate coherent structures into a large-scale perspective. While the model performs equally well over land and water bodies, its applicable time frame is limited to daytime predictions only. Finally, the generated data can be leveraged to build a comprehensive database of 3D cloud structures that is to be exploited in proceeding applications.
Vadose Zone evolution under shifting cultivation practices in Northeast India.
Authors: Sharma Shubhanshu , Yadav Brijesh Kumar
Published: February 2023

Shifting cultivation is one of the old methods of farming practiced in various countries, including India, where land is cleared by slash and burn. In India, shifting cultivation, locally known as Jhum, is extensively practiced in its North-eastern states. Since using fire removes the forest land, it is said to have various implications on the vadose zone properties, along with an increase in sediment yield from runoff. The available literature on the effect of Jhum cultivation includes general studies on areas with different intensities of Jhum. Still, the Jhum sites have significant topography and geography variations, making it difficult to evaluate the effects of Jhum cultivation accurately. Therefore, to understand the impacts of Jhum in Northeastern regions in India, three Jhum sites are selected in a micro-catchment under similar topographical conditions in the Aizawl district of Mizoram state in India. Three sites represented various stages of Jhum cultivation, namely Non-Jhum land (NJL) or fallow land, Cultivated Jhum Land (CJL), and Newly Burnt Jhum land (NBJL). The Impacts of Jhum on various physicochemical properties of the vadose zone soils are reviewed thoroughly under multiple stages of Jhum. Hydraulic conductivity measured using Inversed Augur Hole Method gave maximum hydraulic conductivity at NBJL, followed by NJL and CJL. Water and sediment samples were collected from the downhill streams at selected gauging sites near the three Jhum sites. Soil samples were also collected from the selected sites at different depths viz top surface, 5 cm, and 55 cm, such that the impact of Jhum is quantified at various stages after clearing the forest land, along with variation in soil properties with depth. Laboratory analysis of the soil samples showed that Soil Organic Matter (SOM) and Soil Organic Carbon (SOC) values decreased as we moved from the surface to 55 cm below the ground at all three sites. Soil structure in all three areas was similar, with maximum percentages of medium to fine sand suggesting only minor changes due to burning. Further, pre-monsoon and post-monsoon comparison of all the soil/sediment and water quality characteristics is done. Estimation of Macro-nutrients with few micro-nutrients is also done for soil and sediment samples to study the changes in nutritional characteristics of soil at various stages of Jhum. The result of this study would help in managing the soil-water resources of the region and understanding the sustainability of this form of agriculture.
Quantity vs. Efficiency: Differing patterns of self-organized xerophytic shrubs lead to distinct rain harvesting strategies
Authors: Yuan Chuan , Guo Li , Levia Delphis F. , Rietkerk Max , Fu Bojie , Gao Guangyao
Published: February 2023

Canopy structure alters net precipitation inputs, partly governing the quantity of water recharging soil moisture. Clumped and scattered shrublands are structured with aggregated and isolated canopies, respectively, demonstrating contrasting self-organized patterns. However, the influence of self-organization on rain harvesting is largely unknown. Hence, we compared rainfall redistribution patterns of different self-organized shrubs of Vitex negundo and soil moisture responses during the 2020–2021 rainy seasons on the Loess Plateau of China. Our results indicated that the scattered shrubs harvested more throughfall (85.6% vs. 74.7%) and net precipitation (90.8% vs. 83.8%) than clumped shrubs. Comparatively, stemflow of clumped shrubs was initiated (57.2 vs. 60.4 min) and peaked (198.9 vs. 207.7 min) earlier, ceased later (84.4 vs. 54.5 min), lasted longer (8.9 vs. 8.4 h), transported more swiftly (397.0 vs. 373.8 mm∙h–1), and yielded a larger quantity (400.8 vs. 355.1 mL), respectively. This flux was funneled more efficiently with 160.1 vs. 140.5 fold to rain per branch, and was productive (1.768 vs. 1.346 mm‧g–1) with unit biomass investment per event. For both self-organized patterns, more throughfall led to wetter soils, but more stemflow resulted in quicker response of soil moisture. Comparatively, the top-layer soil moisture remained more stable post rain under clumped shrubs. Therefore, via canopy interception, the scattered organization was conducive for V. negundo to harvest more rain, but the clumped shrubs harvested rain more efficiently. This might relate to morphological adaptations of shrubs to resist drought and consequent formation and maintenance of self-organizations at the landscape scale.
Late Quaternary glacial-interglacial variability of the Indonesian Throughflow and Australian summer monsoon: Evidences from clay mineral and grain size records at IODP Site U1483 of northwest Australia
Authors: Sarim Muhammad , Xu Jian
Published: February 2023

Late Quaternary clay mineral assemblages, radiogenic isotope, and siliciclastic grain size records collected from high sedimentation Site U1483 of the International Ocean Discovery Program (IODP), beneath the path of the modern-day Indonesian Throughflow (ITF) and Leeuwin Current of northwest Australia are studied to reconstruct sediments provenance, transport processes and ocean current behavior, and to evaluate the Australian summer monsoon over the last 500 kyr. Clay minerals are primarily composed of smectite (41–70 %), followed by kaolinite (10–28 %), illite (13.5–25 %), and minor chlorite (3–14 %). Our reconstructed model based on the clay minerals source comparison and radiogenic isotope (Sr-Nd-Pb) records suggest the Victoria and Ord rivers of the Kimberley region as the source over the past 500 kyr for Site U1483. Smectite is mainly derived from the mafic volcanic and smectite-rich Bonaparte Gulf, whereas kaolinite and illite are primarily derived from felsic igneous and metamorphic rocks, respectively, found in the drainage areas of these rivers. Chlorite is primarily contributed by the Indonesian Throughflow (ITF), with a minor contribution from the northwest Australian rivers. Variations in the clay mineral assemblages and grain size records indicate strong glacial-interglacial cyclicity, with small grain size, high smectite, and low kaolinite and illite during glacial periods, while interglacial intervals are marked by a relative increase in kaolinite and illite, mean grain size, and decrease in smectite content. (Kaolinite+illite+chlorite)/smectite and kaolinite/smectite ratios are adopted as proxies for the ITF strength and Australian summer monsoon, respectively. High values of kaolinite/smectite and (kaolinite+illite+chlorite)/smectite ratios during the interglacial intervals indicate a wet summer monsoon with high river discharge and a strong ITF and Leeuwin Current, which has the capacity to transport a relatively high percentage of large-size kaolinite and illite sediments to Site U1483. In contrast, during glacials, the low values of kaolinite/smectite and (kaolinite+illite+chlorite)/smectite ratios imply a dry summer monsoon with low sediment discharge and weak ITF and Leeuwin Current, which can majorly carry the small smectite size particles in its suspension. The mean grain size and clay/silt ratio also indicate that the strength of ITF and Leeuwin Current was weak during glacials and gained high strength during the interglacials. The proxy records’ spectral analysis indicates a strong eccentricity period of 100-kyr, an obliquity period of 41-kyr, and a precession period of 23-kyr, implying that the clay mineral input along the northwest Australian margin is influenced by both high-latitude ice sheet forcing and low-latitude tropical processes.
High-biased climate sensitivity estimates from mid-Pliocene Warm Period temperatures
Authors: Renoult Martin , Sagoo Navjit , Mauritsen Thorsten
Published: February 2023

The warm Pliocene epoch is used to estimate Earth's equilibrium climate sensitivity (ECS), which is the long-term temperature change after a sustained doubling of atmospheric CO2 over pre-industrial levels. Using an emergent constraint on the relationship between mid-Pliocene Warm Period simulated temperatures and ECS, we estimate ECS to be 4.8 K, which is higher than previous studies on the Pliocene. This is partly due to using warmer SST reconstruction than before; a consequence of focusing modelling efforts on the mid-Pliocene warm period. Using the temperatures of a broader period within the Pliocene, we quantify ECS to be 3.1 K. Further uncertainties on proxy data and data-model disagreements are expected to affect ECS estimates. We find that CO2 uncertainties are the main driver of variations in ECS estimates, followed by biases from seasonal temperatures. The bias from polar amplification is apparently small, but could be an overlooked source of error. We conclude that the Pliocene-based emergent constraint is nonetheless robust and is likely to improve further as geological reconstructions improve.
Regional Climate Expected to Continue to Change Significantly After Net-Zero CO2 Emissions Reached
Authors: MacDougall Andrew H. , Mallett Josie , Hohn David , Mengis Nadine
Published: February 2023

The Zero Emissions Commitment (ZEC) is the expected temperature change following the cessation of anthropogenic emissions of climate altering gases and aerosols. Recent model intercomparison work has suggested that global average ZEC for CO2 is close to zero. However there has thus far been no effort to explore how temperature is expected to change at spatial scales smaller than the global average. Here we analyze the output of nine full complexity Earth System Models which carried out standardized ZEC experiments to quantify the ZEC from CO2. The models suggest that substantial temperature change following cessation of emissions of CO2 can be expected at large and regional spatial scales. Large scale patterns of change closely follow long established patterns seen during modern climate change, while at the regional scale patterns of change are far more complex and show little consistency between different models. Analysis of model output suggest that for most models these changes far exceed pre-industrial internal variability, suggesting either higher climate variability, continuing changes to climate dynamics or both. Thus it appears likely that at the regional scale, where climate change is directly experienced, climate disruption will not end even as global temperature stabilizes. Such indefinite continued climate changes will test the resilience of local ecosystem and human societies long after economic decarbonization is complete. Overall substantial regional changes in climate are expected following cessation of CO2 emissions but the pattern, magnitude and sign of these changes remains highly uncertain.
Detection and attribution of climate change using a neural network.
Authors: Bône Constantin
Published: February 2023

A new detection and attribution method is presented using a neural network and applied here to the global surface air temperature (GSAT) from 1900 to 2014.
The changes of the GSAT are attributed to the variations of greenhouse gases, anthropogenic aerosols, and natural forcings. Using the outputs from CMIP6 (Coupled model intercomparison project phase 6) climate models simulations, we train a convolutional neural network (CNN) to reproduce the GSAT simulated by the historical simulations from that of single-forcing simulations. Then, we use a a interpretable AI method : the backward optimization of the trained CNN to estimate the attributable changes. Such a method does not imply any additivity hypothesis in the effects of the forcings. The uncertainty is estimated using different random single-forcings members as starting points for the backward optimization. For comparison, the attributable changes are also calculated using the regularized optimal fingerprinting (ROF) method. The skills of both methods are evaluated following a perfect model approach. The attributed changes are coherent for both methods in terms of amplitude and with some differences in term of uncertainties. The method presented can be adapted and extended in future work, to attribute the changes of other physical variables or to focus on the regional scale where the non-additivity of the effect of forcings could be more present.
Keywords : detection and attribution, climate models, non-additivity, neural networks, interpretable AI
Potential of Waste to Generate Heat at a Domestic Scale
Authors: Das Darpan , Matharu Avtar , Briers Hannah , Carslaw Nicola
Published: February 2023

Rising energy costs and net zero carbon goals mean that the UK needs plentiful and clean energy sources. Current clean energy sources (biomass/ heat pumps) in the country are insufficient to meet residential space heating demands. Further with the advent of higher energy costs, residents are expected to start burning more solid fuel in their homes, as opposed to using gas-based central heating. The UK generates 222.2 million tonnes of waste annually, of which only ~45% is recyclable. The typical calorific value of municipal solid waste and agricultural/garden waste is ~10 MJ/kg and ~20 MJ/kg respectively. Traditionally, waste to energy (WtE) for the circular economy has been associated with waste incineration, but it could be used for household heating. Efficient utilization of waste through different thermochemical transition pathways has been primarily explored at an incineration plant scale (~50 MW heat) and not at a scale of residential heating stove (~5 kW). In the present study, we will use thermogravimetric analyzer- mass spectrometer (TGA-MS) to simulate conditions inside a heating stove. Reaction parameters would include packed bed temperature of 650 °C and heating rate of 10 °C/min for characterisation and assessment of the volatile species evolved during the thermal degradation of several waste materials. Pyrolysis behaviour of some typical household wastes would be analysed through characteristic reaction temperatures and evaluation of mass loss rates. The results from this study can contribute to better evaluation and testing of different waste materials with the aim to know their technical and economic feasibility for heat generation at a small scale.
Comprehensive analysis of high-resolution dispersion simulations in urban area using the GRAMM/GRAL model
Authors: May Maximilian , Wald Simone , Vardag Sanam N.
Published: February 2023

During the last decade, atmospheric measurement networks in urban areas have become important drivers for global pollution and greenhouse gas (GHG) mitigation. For city stakeholders to effectively plan GHG emissions mitigation measures and to monitor changes in emissions, GHG concentration data both, from measurements and simulations on high resolution, are required, but still lacking in most cities. The accurate simulation of high-resolution dispersion in urban areas enables the interpretation of concentration measurements as well as quantitative estimates of local emissions in an inverse modelling framework.High-resolution dispersion simulations on neighborhood scale are generally computationally costly, preventing the analysis of long time periods. To overcome this limitation, we use the coupled GRAMM/GRAL model which is computationally efficient due to a ‘catalogue approach’. GRAMM/GRAL is composed of the mesoscale model GRAMM, solving the Reynolds Averaged Navier Stokes equations for an outer domain (resolution 100 m), and the computational fluid dynamics model GRAL for an inner domain (resolution 10 m). We run GRAMM for 1008 different wind situations differing in synoptic wind forcing and stability class. GRAL is initialized by the GRAMM fields and calculates wind fields taking the flow around buildings into account.  A time series of hourly, 10 m resolved wind fields and concentrations can be obtained by matching catalogued, simulated wind fields with measurement of a local wind measurement network (‘catalogue approach’).Here, we evaluate the GRAMM/GRAL model in the urban area of Heidelberg for 12 months. 14 wind measurement stations within the inner GRAL domain enable a thorough evaluation of GRAL for yearly time periods and for a 12x12 km2 area under challenging topography. Our evaluation also includes wind profile measurements (up to 200 m) from a LIDAR. We find good agreement between modelled and simulated wind directions. Wind speeds can be simulated with an overall root-mean square difference of about 1 ms-1 and a mean bias of about -0.3 ms-1. Measurement sites with poorer model representation are located in the forest or the outer domain with coarser resolution. We conclude that GRAMM/GRAL is capable of simulating high-resolution wind fields in urban areas of complex topography. We showcase first dispersion simulations for carbon dioxide in Heidelberg.
Decadal Trends in the Oceanic Storage of Anthropogenic Carbon from 1994 to 2014
Authors: Müller Jens Daniel , Gruber Nicolas , Carter Brendan , Feely Richard , Ishii Masao , Lange Nico , Lauvset Siv K , Murata Akihiko , Olsen Are , Pérez Fiz F , Sabine Christopher , Tanhua Toste , Wanninkhof Rik , Zhu Donghe
Published: February 2023

The oceanic sink for anthropogenic CO2 (Cant) that humans have emitted into the atmosphere has been pivotal for limiting global warming. The transport of Cant from the surface into the ocean interior, where most of it is accumulating, is the rate limiting step for this uptake. Yet multi-decadal trends in the ocean interior storage of Cant have not been assessed at global scale. We determined such trends by applying the eMLR(C*) regression method to ocean interior observations collected between 1989 and 2020, and found that the global ocean storage of Cant grew by 29 ± 3 Pg C dec-1 and 27 ± 3 Pg C dec-1 (±1σ) from 1994 to 2004 and 2004 to 2014, respectively. Although the two growth rates are not significantly different, they imply a reduction of the oceanic uptake fraction of the anthropogenic emissions from 36 ± 4 % to 27 ± 3 % during the respective decades. We attribute this reduction to a decrease of the ocean buffer capacity and changes in ocean circulation. In the Atlantic Ocean, the maximum storage rate shifted from the Northern to the Southern Hemisphere, plausibly caused by a weaker formation rate of North Atlantic Deep Waters and an intensified ventilation of mode and intermediate waters in the Southern Hemisphere. Between 1994 and 2004, the oceanic Cant accumulation exceeded the net air-sea flux by 8 ± 4 Pg C dec-1, suggesting a loss of natural carbon from the ocean during this decade. Our results reveal a substantial vulnerability of the ocean carbon sink.
Ensemble Data Assimilation in NEMO using PDAF
Authors: Nerger Lars , Sun Yuchen , Düsterhöft-Wriggers Wibke , Chen Yumeng , Partridge Dale
Published: February 2023

NEMO itself does not provide full functionality for data assimilation. To enable data assimilation with NEMO, it was coupled with the Parallel Data Assimilation Framework (PDAF, https://pdaf.awi.de). PDAF is open source software providing generic functionality for data assimilation (ensemble filters and smoothers, and variational schemes) as well as ensemble simulations, related diagnostics and tools. For computational efficiency the coupling to NEMO was performed by inserting a few subroutines in higher-level routines of NEMO, which call functions of PDAF. This scheme allows for an in-memory exchange of model fields with the data assimilation software in order to avoid excessive file outputs and model restarts. Alternatively, an offline-coupling using disk files is possible. Next to the NEMO ocean physics, also components like the sea ice or biogeochemical models can be handled, which allows for fully multivariate data assimilation.We discuss the structure and functionality of the implementation with a focus on ensemble filters. The application is exemplified using two setups; NEMO with the biogeochemistry model ERGOM configured at high resolution for the Baltic Sea, and a global eORCA1 configuration coupled with the FABM-MEDUSA biogeochemistry model.
Evaluating recent and future changes in North Atlantic stratification with complementary energetics and water mass frameworks
Authors: Marsh Robert , Dey Dipanjan , Drijfhout Sybren
Published: February 2023

Subpolar and high-latitude regions of the North Atlantic are subject to changing buoyancy and mechanical forcing, alongside changing heat and freshwater exchanges with subtropical and polar regions. Associated changes in water mass formation and circulation are accompanied by changes in upper ocean stratification, of consequence for the large-scale ocean circulation, air-sea interaction, and ocean biogeochemistry. Changes in water mass volumes, and the associated overturning circulation, have been extensively evaluated with the water mass transformation (WMT) framework. Changes in stratification may be quantified with the Potential Energy Anomaly (PEA) framework, which has been extensively applied to seasonally stratified shelf sea environments. The WMT and PEA frameworks in combination provide complementary and holistic insights, for understanding hydrographic changes in relation to selected drivers. These frameworks are used with high-resolution model ocean datasets, obtained from hindcast and coupled simulations, the latter in control mode and forced by rising greenhouse gas concentrations through the 20th and 21st centuries. For selected sub-regions of the subpolar North Atlantic, bound by OSNAP and neighbouring hydrographic sections, mapped stratification (PEA) anomalies are related to respective changes in surface heat and freshwater fluxes. Residual differences between buoyancy-forced and full PEA tendencies are attributed to vertical mixing and divergences of heat and freshwater transports. Changes in regional stratification are evaluated alongside corresponding rates of water mass transformation and associated volumetric variability, for selected water masses. Eulerian perspectives provided by the WMT and PEA frameworks further complement Lagrangian perspectives provided by particle tracking. In full combination, these diagnostics elucidate multiple drivers of change in the North Atlantic that have potentially far-reaching consequences for the wider Earth System.
Integrated 3D modelling of the lithospheric mantle under the West and Central African rift system and surronding.
Authors: Fosso Teguia M Estelle Eric , Ebbing Jörg
Published: February 2023

We present the result of an integrated petrological and geophysical 3D modelling of the lithospheric mantle over the West and Central African rift system. For modelling, the integrated geophysical and petrological forward modelling software LitMod3D has been used. The initial geometry of the model is based on the Moho depth and base lithosphere of the global model WINTERC-G, and the sediment thickness from the global model Crust1.0 and the available seismic Moho depth have been used for validation. The model is fitted to satellite gravity gradients and the Bouguer anomaly calculated from the XGM2019e-2190 model. Different classes of mantle composition data have been considered and by iteratively trying to compute the best fitting between different modelled and observed signals, the final models of density, velocity and temperature distributions have been estimated. The model shows lateral transitions curved shape, extending horizontally for about 50km, between the West and Central African rift system, and the surrounding Congo craton and West African craton. More in detail, the results show the lateral and vertical variation of density, temperature and velocity in respect between the different lithospheric mantle domains. We notice the absence of a clear signature of the Saharan meta-craton, making this area more similar to the West and Central African rift system than the bordering cratons. Moreover, the modelled density profile shows a continuous depth dependent gradient under the rift system, but three steps in the depth profile under the cratons, suggest a layering of the lithospheric mantle with respect to its density gradient, which can be interpreted as metasomatism of the lower lithospheric mantle.
Numerical investigation with a coupled single-column surface-atmosphere model and an application to central Mediterranean
Authors: Goyette Stéphane , Kasparian Jérôme
Published: February 2023

An atmospheric single-column model (SCM) developed in the framework of the Canadian Regional Climate Model, CRCM, driven by NCEP-NCAR reanalyses is applied to study the non-linear interactions between the surface and the planetary boundary layer (Goyette et al., 2020). The approach to solve the model equations and the technique described may be implemented in any RCM system environment as a model option. The working hypothesis underlying this SCM formulation is that a substantial portion of the variability simulated in the column can be reproduced by processes operating in the vertical dimension and a lesser portion comes from processes operating in the horizontal dimension. This SCM offers interesting prospects as the horizontal and vertical resolution of the RCM is ever increasing. Due to its low computational cost, multiple simulations may be carried out in a short period of time. In this paper, a range of possible results obtained by changing the lower boundary from open water surface to land, and by varying model parameters are mainly shown for central Mediterranean but also for other applications. Results show that the model responded in a highly nonlinear but coherent manner in the lowest levels with changes in air temperature, moisture and windspeed profiles. The latter are consistent with those of the surface vertical sensible, latent heat and momentum fluxes. For example in the central Mediterranean, during a simulated year, air temperature is increased during all the seasons. Specific humidity is increased during the autumn and winter seasons but decreased by during the spring and summer seasons thus showing the contrasting influence of the land surface. The potential for further developments, as well as some guidance as to how to handle mixed land/open water coupling in RCMs, is also provided.GOYETTE, Stéphane, FONSECA, Cédric, TRUSCELLO, Léonard. Assessment of nonlinear effects of a deep subgrid lake with an atmospheric single‐column model. In: International Journal of Climatology, 2020. doi: 10.1002/joc.689
Quantifying sources, pathways, and controls on sediment transport dynamics in two rivers on James Ross Island, Antarctica
Authors: Stringer Christopher D. , Boyle John F. , Hrbacek Filip , Laska Kamil , Nedělčev Ondřej , Kavan Jan , Kňažková Michaela , Carrivick Jonathan L. , Quincey Duncan J. , Nývlt Daniel
Published: February 2023

The Antarctic Peninsula is now warming again after a hiatus in temperatures, and ice masses are receding at an enhanced rate, resulting in the enlargement of proglacial regions. Despite the importance of proglacial regions as sediment sources in polar environments, few studies focus on the Antarctic and sub-Antarctic fluvial sediment dynamics and even fewer have explored the spatio-temporal variability in sediment delivery or compiled a comprehensive source-to-sink description of sediment transportation. Proglacial rivers are shaped by the interplay of glacial meltwater, which erodes, transports, and deposits sediment, and hillslope activity, which provides new sediment to the riverine system during mass transport events. Active layer soils can be an additional source of water and sediment when ground temperatures are above freezing; particularly in catchments with low glacier cover. In this study, we aim to discuss how different environmental factors, such as air temperature, active layer thaw, and precipitation affect sediment yields in two rivers on James Ross Island, Antarctica. Based on field data collected at the start of 2022, we used a multi-disciplinary approach to quantify the spatio-temporal variability in sediment yields across the river catchments of the Algal and Bohemian Streams and their key environmental controls. Additionally, we discuss how X-ray fluorescence and infrared spectroscopy have provided an insight into how sediment composition and, potentially, source change downstream in each stream. We estimate that the annual sediment yield for the Bohemian Stream in the austral summer of 2021/2022 was 400 tonnes/year/ km2 and 530 tonnes/year/ km2 for the Algal Stream. While the Algal Stream has a higher estimated yield, its daily sediment yield values are highly variable and the Bohemian Stream typically exports more sediment into the Southern Ocean. Our results show that the active layer is an important driver of sediment yield variability in the Algal catchment. In contrast, sediment yield from the Bohemian catchment is more sensitive to air temperature. Both catchments are sensitive to changes in precipitation. The differences in sediment yield from the two catchments likely stem from differences in glacier and snowfield coverage. These sediment yield values are exceptionally high by Antarctic standards, and are comparable to that from catchments on Svalbard, although they remain low by global standards. Our identification of the controls on sediment yield provides insight into how other fluvial sedimentary systems across the Antarctic Peninsula could respond as glaciers lose mass in a warming climate.
OGC Testbed-18 Machine Learning Training Datasets Task: Application of standards to Machine Learning training datasets
Authors: Lavender Samantha , Adams Caitlin , Ivánová Ivana , Williams Kate
Published: February 2023

Training datasets are a crucial component of any machine learning approach, with significant human effort spent creating and curating these for specific applications. However, a historical absence of standards has resulted in inconsistent and heterogeneous training datasets with limited discoverability and interoperability. Therefore, there is a need for best practices and guidelines for generating, structuring, describing, and curating training datasets.The Open Geospatial Consortium (OGC) Testbed-18 initiative covered several topics related to geospatial data, focussing on issues around cataloguing and interoperability. Within Testbed-18, the Machine Learning Training Datasets task aimed to develop a foundation for future standardization of training datasets for Earth observation applications.For this task, members from Pixalytics, FrontierSI, and Curtin University authored an Engineering Report that reviewed:·       Examples of how training datasets have been used in Earth observation applications·       The current best-practice methods for documenting training datasets·       The various requirements for training dataset metadata·       How the Findability, Accessibility, Interoperability, and Reuse (FAIR) principles apply to training datasetsThe Engineering Report provides a foundation that OGC can leverage in creating the future standard for machine learning training data for Earth observation applications. The Engineering Report also provides a useful overview of the state of work and key considerations for anyone wishing to improve how they document their training datasets.In our presentation, we discuss the key findings from the Engineering Report, including key metadata identified from Earth observation use cases, the current state of the art, thoughts on cataloguing and describing training data quality, and how the FAIR principles apply to training data. 
Space-time modelling of co-seismic and post-seismic landslide hazard via Ensemble Neural Networks.
Authors: Dahal Ashok , Tanyas Hakan , Van Westen Cees , Van der Meijde Mark , Mai Paul Martin , Huser Raphael , Lombardo Luigi
Published: February 2023

Until now, a full numerical description of the spatio-temporal dynamics of a landslide could be achieved only via physics-based models. The part of the  geoscientific community  developing data-driven model has instead focused on predicting where landslides may occur via susceptibility models. Moreover, they have estimated when landslides may occur via models that belong to the early-warning-system or to the rainfall-threshold themes. In this context, few published researches have explored a joint spatio-temporal model structure. Furthermore, the third element completing the hazard definition, i.e., the landslide size (i.e., areas or volumes), has hardly ever been modeled over space and time. However,  technological advancements in data-driven models have reached a level of maturity that allows to model all three components (Where, When and Size). This work takes this direction and proposes for the first time a solution to the assessment of landslide hazard in a given area by jointly modeling landslide occurrences and their associated areal density per mapping unit, in space and time. To achieve this, we used a spatio-temporal landslide database generated for the Nepalese region affected by the Gorkha earthquake. The model relies on a deep-learning architecture trained using an Ensemble Neural Network, where the landslide occurrences and densities are aggregated over a squared mapping unit of 1x1 km and classified/regressed against a nested 30~m lattice. At the nested level, we have expressed predisposing and triggering factors. As for the temporal units, we have used an approximately 6-month resolution. The results are promising as our model performs satisfactorily both in the susceptibility (AUC = 0.93) and density prediction (Pearson r = 0.93) tasks. This model takes a significant distance from the common susceptibility literature, proposing an integrated framework for hazard modeling in a data-driven context.To promote reproducibility and repeatability of the analyses in this work, we share data and codes in a GitHub repository accessible from this link: https://github.com/ashokdahal/LandslideHazard. 
The response of the North Pacific jet and stratosphere-to-troposphere transport of ozone over western North America to RCP8.5 climate forcing
Authors: Elsbury Dillon , Butler Amy H. , Albers John R. , Breeden Melissa L. , Langford Andrew O'Neil
Published: February 2023

Stratosphere-to-troposphere transport (STT) is an important source of ozone for the troposphere, particularly over western North America. STT in this region is predominantly controlled by a combination of the variability and location of the Pacific jet stream and the amount of ozone in the lower stratosphere, two factors which are likely to change if greenhouse gas concentrations continue to increase. Here we use Whole Atmosphere Community Climate Model experiments with a tracer of stratospheric ozone (O3S) to study how end-of-the-century Representative Concentration Pathway (RCP) 8.5 sea surface temperatures (SSTs) and greenhouses gases (GHGs), in isolation and in combination, influence STT of ozone over western North America relative to a preindustrial control background state.            We find that O3S increases up to 39% at 700 hPa over western North America in response to RCP8.5 forcing with the largest increases occurring during late winter and tapering off during spring and summer. The GHGs are primarily responsible for these tropospheric O3S changes. Both the future SSTs and the future GHGs accelerate the Brewer Dobson circulation, which increases extratropical lower stratospheric ozone mixing ratios. While the GHGs promote a more zonally symmetric lower stratospheric ozone change due to enhanced ozone production and some transport, the SSTs increase lower stratospheric ozone predominantly over the North Pacific via transport associated with a stationary planetary-scale wave. Ozone accumulates in the trough of this anomalous wave and is reduced over the wave’s ridges, illustrating that the composition of the lower stratospheric ozone reservoir in the future is dependent on the stationary planetary-scale wave response to future SSTs. In addition, the future SSTs are found to prompt most changes to the large-scale circulation in the troposphere and stratosphere compared to the effect of the GHGs. These changes include modifying the position and speed of the future North Pacific jet, lifting the tropopause, accelerating both the Brewer-Dobson Circulation’s shallow and deep branches, and enhancing two-way isentropic mixing in the stratosphere.
Can we measure evaporation using commercial microwave links?
Authors: van der Valk Luuk , Hartogensis Oscar , Coenders-Gerrits Miriam , Hut Rolf , Walraven Bas , Uijlenhoet Remko
Published: February 2023

The aim of this study is to investigate whether it is feasible to obtain evaporation estimates from commercial microwave links, which are normally used for telecommunication. These commercial microwave links are already used to monitor path-averaged precipitation by determining the rain-induced attenuation along the link path. The signal transmitted by these microwave links is also perturbed by turbulence during dry periods, which consists of diffraction of the emitted beam by turbulent eddies. This is known as the scintillation effect and special microwave links, called scintillometers, have been designed to measure the full spectral range of the signal intensity fluctuations caused by the scintillation effect and link these fluctuations to the turbulent heat fluxes. However, commercial microwave links are usually sampled at too low temporal resolution to directly capture all the relevant scintillation fluctuations (typically between 0.1 – 100 s). Currently, the links are most often sampled at a temporal resolution of 15 minutes with a recording of the minimum and maximum values, while more recently also “active” forms of sampling with possible intervals up to 1 s have been set up. We intend to investigate what kind of sampling is required to obtain the structure parameter of the refractive index, Cnn, from commercial microwave link data. We will use high resolution sampling rates, which we resample to mimic various commercial sampling strategies. Subsequently, we aim to compute evaporation through deriving the structure parameters for temperature, Ctt, and humidity, Cqq, through a combination with auxiliary data. For this research, we will use data from a dual-beam scintillometer setup, a RPG-MWSC 160 GHz and a Large-Aperture Scintillometer with a 15 cm diameter over a 850 m path over the Ruisdael Observatory at Cabauw, the Netherlands. Additionally, we will install a Nokia Flexihopper 38 GHz, formerly part of a telecom network in the Netherlands, serving as our commercial microwave link. On the measurement site, many other relevant meteorological measurements for studying evaporation (e.g. temperature, humidity, turbulence and energy fluxes) are performed, which we will use as auxiliary and reference data. During this poster session, we would like to present our research plans and invite fellow session participants to join the discussion and give feedback on our ideas.
The WInd-blown Sand Experiment (WISE) – UAE: Introduction and first results
Authors: Nelli Narendra , Francis Diana , Sow Mamadou , Bosc Emmanuel , Bergametti Gilles
Published: February 2023

The Arabian Peninsula is among the major dust sources on Earth. Here, dust storms occur frequently as a result of the action of surface winds on desert surface such as the Empty Quarter Desert located in southern Arabian Peninsula. Despite being a frequent occurrence, no direct measurement of dust emission in this region existed to date. In summer 2022, the WInd-blown Sand Experiment (WISE) kicked off in the Empty Quarter area located in southern United Arab Emirates (UAE). The aim of the experiment is to quantify dust emission from this major dust source through direct observations. A full set of instrumentation is being operated to study saltation, winds, temperature, humidity, radiative fluxes, physical and optical properties of dust aerosols, atmospheric electric field, and soil properties. In this presentation, we describe the instrumentation being used in WISE UAE and we show some preliminary results during different weather regimes such as strong wind erosion, local convection, dense radiation fog and land-sea breeze. The analysis of atmospheric electric field data suggests the presence of relatively higher electric field at the onset of sea breeze occurrence and wind erosion events. The detailed investigation on relative humidity, frictional velocity, dust particle size distribution impact on the electric field will be presented. WISE is a first-of-its-kind experiment in the region and it aims ultimately at improving dust parametrizations in numerical models. We hope that this presentation at the EGU can trigger collaborations in this direction.