bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of tropical SSTs on the monthly signal over the North Atlantic-European region
Authors: Ivasić Sara , Herceg Bulić Ivana , Popović Margareta
Published: February 2023

Targeted numerical simulations were designed to test the potential impact of tropical sea surface temperatures (SSTs) on the geopotential heights at 200 hPa (GH200) signal over the North Atlantic-European region. Five experiments with SST anomalies prescribed in different areas, acting as lower boundary forcing, were created with an intermediately complex atmospheric general circulation model (ICTP AGCM). In the AGCM experiments, the SST forcing was prescribed globally, in the tropical zone of all oceans, only in the tropical Atlantic, tropical Indian Ocean and limited to the tropical Pacific. All of the simulations covered a 156-year-long period.The monthly GH200 signal was calculated based on the difference between the ensemble mean of each experiment and the climatological mean for the considered period. In addition, to inspect the impact of the El Niño-Southern Oscillation (ENSO), the signal was calculated for ENSO and non-ENSO years, respectively. Here, the ENSO years were classified according to the value of the late-winter Niño3.4 index.Additionally, each experiment’s monthly signal was averaged over the signal maximum over the North Atlantic-European region. The characteristics of the spatially averaged signal were compared to the signal averaged over a similar signal maximum observed over the Pacific North American region.Results have shown that the GH200 signal is the strongest in the late-winter months in all experiments. The AGCM experiment with SST boundary forcing prescribed only in the tropical Atlantic consistently had the smallest signal amplitude. The strongest signal linked to ENSO events was found in the experiment with the SST forcing prescribed only in the tropical Pacific. The signal averaged over the NAE maximum generally yields smaller values than the PNA maximum average. Also, the differences between the (non) ENSO signal and the signal for all years are less pronounced in the case of the NAE maximum average.
Erosion rate maps of the Northern Andes highlight spatio-temporal patterns of uplift and quantify sediment export
Authors: Ott Richard , Perez-Consuegra Nicolas , Scherler Dirk , Mora Andres , Huppert Kimberley , Braun Jean , Hoke Gregory
Published: February 2023

Erosion rates are commonly used to study tectonic uplift and sediment export from mountain ranges. However, the scarcity of erosion rate data often hinders detailed tectonic interpretations. Here, we present 25 new erosion rates from the Northern Andes of Colombia, determined from cosmogenic 10Be measurements, to study spatial and temporal patterns of uplift along the Central and Eastern Cordillera. These rates, along with published data and precipitation-corrected normalized channel steepness measurements, were used to create high-resolution erosion rate maps. The results show that the southern Central Cordillera has relatively uniform erosion rates, averaging around 0.3 mm/a, while the northern Central Cordillera exhibits rapidly eroding canyons dissecting slowly eroding low-relief surfaces. We interpret that long-term, steep slab subduction has led to an erosional steady-state in the southern Cordillera Central, while Late Miocene slab flattening caused an acceleration in uplift in the northern Cordillera Central which the landscape has not yet adjusted to. The Eastern Cordillera also displays pronounced erosional disequilibrium, with a slowly eroding central plateau rimmed by faster eroding western and eastern flanks. Our maps suggest recent topographic growth of the Eastern Cordillera, with deformation focused along the eastern flank, which is also supported by balanced cross-sections and thermochronologic data. Spatial gradients in predicted erosion rates along the eastern flank of the Eastern Cordillera suggest transient basin-ward migration of thrusts. By using our erosion maps to estimate sediment fluxes, we find that the Eastern Cordillera exports nearly four times more sediment than the Central Cordillera. Our analysis shows that accounting for spatial variations in erosion parameters and climate gradients reveals important variations in tectonic forcing that would otherwise be obscured in traditional river profile analyses. Moreover, given relationships between tectonic, and topographic evolution, we propose that the dynamic landscape evolution of the Northern Andes, as revealed by our erosion maps, is primarily linked to spatial and temporal variations in slab dip, with potentially additional influences from inherited Mesozoic rift structures.
Dynamical Impacts of Warm-Starting Operational Weather Models over Africa
Authors: Morris Fran , Warner James , Bain Caroline , Schwendike Juliane , Parker Doug , Petch Jon
Published: February 2023

Weather models which allow explicit convection can add value to weather forecasting by improving the intensity and timing of precipitating systems and their dynamics, which is particularly valuable in the tropics where moist diurnal convection dominates. In West Africa, convection can become organised to form mesoscale convective systems which are crucial for supplying water but may have devastating impacts, and while convection-permitting models improve forecasts, issues remain in the implementation of operational convection-permitting models. A major problem is initialising weather models in the tropics, where measurements are sparse and weather systems are dominated by nonlinear diabatic processes, which makes data assimilation challenging. Currently, the UK Met Office runs a regional operational convection-permitting model in Africa, the Tropical Africa Model, which is initialised using lower-resolution global models. However, the global models have extremely limited convective-scale structures and as a result, there is a spin-up time of around 12-18 hours before the model begins to accurately reflect precipitation.To counteract this problem, a “warm-starting” method has been trialled. The warm-starting technique blends large-scale features from the global model and fine-scale fields below a certain length scale from previous runs of the high-resolution model to use as an initial state in a new model run. It combines the more realistic convective structures of the regional model and the more accurate synoptic conditions in the global model. Not only is the approach cheaper and quicker than traditional data assimilation, both in terms of development and computational cost, but it also shows demonstrable improvements in the representation of precipitation for the first 12 hours of the model and beyond relative to simulations where the model has simply been initialised with the global model (a “cold-start”). The cold-start simulations appear to consistently predict rainfall that is too intense even beyond the first 12 hours.We investigate why warm-starting models produces more realistic rainfall distributions by examining the dynamical structures: producing statistics of rainfall objects as forecasts evolve and examining their connection to the dynamics. We examine the energetics of convection in the convection-permitting models, aiming to provide a justification for the scale length at which we include structure from previous model runs using this technique.
Fractionation of nitrogen and oxygen isotopic composition in N2O produced by bacterial denitrification
Authors: Chénier Noémy , Magyar Paul M. , Emmenegger Lukas , Lehmann Moritz F. , Mohn Joachim
Published: February 2023

The isotopic composition of nitrous oxide (N2O) reveals valuable information on the biological production sources that contribute to N2O accumulation in the atmosphere, i.e. denitrification, nitrifier-denitrification and nitrification1. Isotopic fingerprints for each of these microbial pathways have been identified in past work, however, overlapping signatures of co-occurring N2O production processes2, and limitations in the robustness of associated fractionation factors under varying growth/environmental conditions3 still pose significant challenges.We will present data from the initial phase of our project, where we study N2O production and associated N and O isotopic fractionation by the denitrifier Pseudomonas aureofaciens, grown in the laboratory under different growth conditions and thus different reaction kinetics. N2O production was quantified on-line by Fourier-Transformation IR-spectroscopy (FTIR), and the isotopic composition of produced N2O was determined by quantum cascade-laser-absorption spectroscopy (QCLAS). The combination of N2O production and isotope data (continuously measured) allowed us to elucidate changes in N and O isotope fractionation in response to changing reaction kinetics.In a later phase of the project, we will expand our isotope-analytical capability by including also the doubly-substituted molecules of N2O, 15N15N16O (556), 14N15N18O (458) and 15N14N18O (548). More specifically, we will interrogate the symmetry of N – N bond formation, verify combinatorial effects during N2O production, and we will test whether Δ556, Δ458, and Δ548 (and the preference for 15N substitution in the central/terminal N-position) can be applied as proxies for reaction kinetics4, 5.  1 Yu, L., Harris, E., Lewicka Szczebak, D., Barthel, M., Blomberg, M.R., Harris, S.J., Johnson, M.S., Lehmann, M.F., Liisberg, J., Müller, C. and Ostrom, N.E., 2020. What can we learn from N2O isotope data?–Analytics, processes and modelling. Rapid Communications in Mass Spectrometry, 34(20), p.e8858.2 Kantnerová, K., Tuzson, B., Emmenegger, L., Bernasconi, S.M. and Mohn, J., 2019. Quantifying isotopic signatures of N2O using quantum cascade laser absorption spectroscopy. Chimia, 73(4), pp.232-232.3 Haslun, J.A., Ostrom, N.E., Hegg, E.L. and Ostrom, P.H., 2018. Estimation of isotope variation of N2O during denitrification by Pseudomonas aureofaciens and Pseudomonas chlororaphis: implications for N2O source apportionment. Biogeosciences, 15(12), pp.3873-3882.4 Yeung, L.Y., 2016. Combinatorial effects on clumped isotopes and their significance in biogeochemistry. Geochimica et Cosmochimica Acta, 172, pp.22-38.5 Kantnerová, K., Hattori, S., Toyoda, S., Yoshida, N., Emmenegger, L., Bernasconi, S.M. and Mohn, J., 2022. Clumped isotope signatures of nitrous oxide formed by bacterial denitrification. Geochimica et Cosmochimica Acta, 328, pp.120-129.
Event clustering for infrasound monitoring system
Authors: charbit maurice , le pichon alexis , poste benjamin , roueff françois , vergoz julien
Published: February 2023

In the area of infrasonic monitoring system, an important task is to clustering the various cells containing asignal of interest to a reduced event number. Indeed, to each time-frequency cell is attached a source direction of arrivals,many of which arise from the same physical event spanning over a large time-frequency window. In PMCC (ProgressiveMulti-Channel Cross-Correlation) the clustering is based on ad hoc rules and metrics provided by a large empirical expertise.
In this study we present a new approach based on a statistical model, associated to the multichannel maximum-likelihood (MCML). More specifically, for each time-frequency cell, the MCML provides the estimations of the slownessvector and of the signal-to-noise ratio (SNR), and the p-value computed from the generalized likelihood ratio (GLR).These quantities are collected within a large window, typically 10 Hz by 1 hour. To reduce the computational time, onlythe cells with p-values below a threshold are considered. The proposed mixture model (MM) is based on the following4-dimensional vector: the time location, the log of the frequency location and the two components of the slowness vector.
 
Each cluster is modeled by a distribution, chosen in a flexible catalog that can still be improved. Today the catalogconsists of Gaussian distribution, uniform distribution and mixture of Gaussian and uniform. A few examples: shorttime event is modeled by a 4D Gaussian, permanent event in a given frequency band, as microbarom or wind turbine, is modeled bya 2D Gaussian for the DOA, a full time uniform distribution for the time location and a uniform distribution in theknown frequency band. For the DOA modeled by a Gaussian, the covariance is taken as the asymptotic covariance ofthe MCML, using the estimated SNR in the corresponding cell. Moreover we introduce a specific cluster to trap falselydetected signals, modeled by a full uniform distribution in the four dimensions.
The estimation of the parameters of the MM is performed by the so-called Expectation Maximization algorithm.Then the maximum a posteriori provides the final clustering. We also present an estimation of the number of eventsbased on the Bayesian information criterion (BIC). Many real observations are considered to illustrate the method.
The main advantages of the proposed method are (i) taking into account the p-value for selecting the cells to cluster,(ii) the flexibility of the model catalog, (iii) the statistical interpretation of the results.
 
Landslide dams around the World – case studies to global datasets
Authors: Dufresne Anja , Fan Xuanmei , Andrea Wolter
Published: February 2023

Landslide dams are an important component of slope-fluvial systems, particularly given their potentially disastrous consequences if they breach suddenly. To further research on dam longevity, stability, and failure mechanisms effectively, comprehensive landslide dam dataset are essential. Yet, such datasets from around the world are heterogeneous in their completeness and data-collection approaches, and we still see many geographical “blind spots” where research on landslide dams appears absent, at least within the published literature.As part of a project to collate and compile a global, accessible landslide-dam database, we present some of the challenges involved in its construction. In addition to data heterogeneity and data gaps, biases and parameter definitions will be discussed and highlighted by several landslide-dam case studies from around the world. The aim of the discussion is to acknowledge these data biases, such as geopolitics, funding, accessibility, and triggering-event factors, and offer solutions for the global research community. We will also clearly define terms that have been vague in landslide-dam research so far. For example, dam height, volume, length and width are not used consistently – even what exactly constitutes a landslide dam can sometimes be a defined differently.  
Analysis of tsunami signals from tide gauges and ocean-bottom pressure gauges through Iterative Filtering
Authors: Angeli Cesare , Armigliato Alberto , Lorito Stefano , Romano Fabrizio , Zanetti Martina , Zaniboni Filippo
Published: February 2023

Time-series from coastal tide gauges and ocean-bottom pressure gauges play a fundamental role in the study and monitoring of tsunami. A typical tsunami record is the result of the superposition with the tsunami itself of different physical phenomena, such as tides, and seismic waves that relatively close to the earthquake source may overlap with the tsunami. In the case of coastal gauges, nonlinear interactions with local bathymetric and coastal morphology features characterize the tsunami evolution. In this study, we apply the recently developed Iterative Filtering (IF) technique, specifically tailored to non-stationary and non-linear signals, to tsunami time-series. IF is a data-driven algorithm that decomposes signals into elementary oscillatory components, called Intrinsic Mode Functions (IMFs), each containing distinct frequency bands. This technique attempts to separate different physical phenomena present in the time-series into different IMF.To complement the decomposition, a time-frequency analysis technique called IMFogram is used. The IMFogram relies on computing for each IMF the local frequency, computed based on the distribution of zero-crossings, and local amplitude, computed interpolating the absolute values of relative maxima. Despite their simplicity, these definitions produce a time-frequency representation that generalizes the traditional spectrogram. The output of the IMFogram algorithm, given in matrix form, can be used to pinpoint time and amplitude of special features of the signal both graphically and quantitatively.The ability to separate the different components of a measured record into different IMFs and analyze their spectral properties is shown by applying the technique to available real-world data, for tsunami of different “intensity” and frequency content. The results are compared to other techniques, such as classical filtering techniques and the Empirical Mode Decomposition (EMD). It is shown that IF results, unlike classical linear filters, do not depend on experts’ choice and, unlike the EMD, are stable w.r.t. to noise. Special attention is given to recent events in the Mediterranean Sea, where robust analysis of each signal is needed to remedy the  absence of deep sea tsunami sensors, the sparsity of coastal tide gauges, and the morphological complexity. At last, the possibility of real-time application in early warning system is considered.
The Short-Term Impact of Air Pollution on Healthcare Expenditures
Authors: Zhang Haofan , Zhu Dianyu , He Pan , Liu Miaomiao , Bi Jun
Published: February 2023

Understanding the health impact of air pollution is critical for understanding the benefit of environmental regulations, especially under the synergies of carbon neutrality and air pollution control. We examine the effect of fine particulate matter (PM2.5) on individual healthcare expenditures in China from 2017 to 2019 using daily transaction data from 320 cities and evaluate the health co-benefits of carbon neutrality. Results show that each 10 μg/m3 increase in daily PM2.5 exposure is associated with a 0.31 percent increase in three-day healthcare consumption and a 0.53 percent increase in three-day individual healthcare expenses. Achieving carbon neutrality goals with the national air quality daily standard of 35 μg/m3 can save 1.5 billion yuan annually. Ambitious goals with World Health Organization Air Quality Guidelines of 15 μg/m3 can nearly double the saving. This study not only provides insight into the potential health benefits of carbon neutrality in China but also suggests that extensive benefits may result from more ambitious targets.
Mapping Groundwater-dependent Ecosystems in Arid Central Asia: Implications for Controlling Regional Land Degradation
Authors: Liu Hu , Liu Chan , Zhao Wenzhi , Yu Yang , Yetemen Omer
Published: February 2023

Groundwater-dependent ecosystems (GDEs) exist all over the world, especially in water-limited regions. To achieve better water management, it is necessary to map and identify GDEs. Central Asia (CA) is one of the most arid regions in the mid-latitudes and one of the major regions with shallow groundwater tables. However, the role of groundwater in the impacts of climate change and regional anthropogenic activities on environmental risks, especially regional desertification, is inadequately understood due to the limited available research on GDEs. In the present study, a remote sensing-based method was used for mapping GDEs in regional CA, and three means—overlay analysis, correlation analysis, and the water balance method—were adopted to validate the accuracy of the mapping outcomes. Our results indicated that: 1) GDEs were concentrated around large lakes and in central Kazakhstan (between 46°N and 50°N latitudes), and areas "Very Likely" and "Likely" to be GDEs accounted for 36.89%, and 28.85% of the total natural vegetation areas, respectively; 2) at the watershed scale, the Sarysu Basin had the largest proportion (94.02% of the area) of potential GDEs while the Ysyk-Kol Basin had the lowest proportion (17.84%); 3) all the three validation methods indicated a good performance for our GDE mapping results. We concluded that the remote sensing-based GDE identification method can be considered a potential approach for mapping GDEs regionally. Better recognition of relationships among groundwater availability, ecosystem health and groundwater management policies should be developed by conducting further studies, to protect GDEs and to prevent regional land degradation.
Findlater jet induced summer monsoon memory in the Arabian Sea
Authors: Kushwaha Vikas Kumar , Kumar Prasanna , Francis Feba , Karumuri Ashok
Published: February 2023

A cross-equatorial low-level wind, known as Findlater Jet (FJ), modulates the thermocline in the Arabian Sea (AS) during the summer monsoon (June to September). By analyzing ocean and atmospheric data, we show that the FJ signal gets ‘trapped’ in the AS in the form of tropical cyclone heat potential till the following winter monsoon months (December to February). This memory is the consequence of the combined effect of FJ-induced wind stress curl and the annual downwelling Rossby waves in the AS. During the summer monsoon months, the strong low-level westerly winds cause a negative wind stress curl in the south of the FJ axis over the central AS, resulting in a deep thermocline and a high magnitude of heat being trapped. In winter monsoon months, though the wind stress curl is positive over large parts of the AS and could potentially shoal the thermocline and reduce the tropical cyclone heat potential in the central AS, this does not happen due to two reasons. Firstly, winds are weaker and spread over a larger area over the AS making the magnitude of the wind stress curl low. Secondly, the westward propagating downwelling Rossby wave radiated from the eastern AS deepens the thermocline and prevents ventilation of the trapped heat. During the following spring, the collapse of the Rossby waves leads to the shoaling and mixing of underlying waters with surface waters thereby resurfacing the trapped heat. The resurfacing of the trapped heat makes the AS a memory bank of the FJ-induced signal.
Catchment-scale hydrological performance of sustainable urban drainage systems in a cold maritime climate undergoing soil freeze-thaw cycles and rain-on-snow events
Authors: Zaqout Tarek , Andradóttir Hrund Ólöf
Published: February 2023

Sustainable urban drainage systems (SUDS) have been increasingly implemented as a low-impact, cost-effective stormwater control measure (SCM). SUDS include a diverse set of infiltration-based measures designed to maintain the pre-development hydrological cycle, reduce runoff, and enhance water quality via infiltration. However, these functions are prone to deterioration during winter, especially when soil frost is present. Unlike inland cold regions, maritime cities are particularly vulnerable to the negative winter impacts due to frequent freeze-thaw cycles, rain-on-snow events, and intermittent midwinter snowmelt. To date, the hydrological efficacy of SUDS at catchment-scale under cyclical cold conditions is still lacking. The goal of this study, therefore, was to evaluate the runoff and volume reduction achieved by a SUDS network in a small, 1.5 ha catchment in Garðabær, Iceland. In addition to assessing the seasonal and spatial variability of infiltration performance of different SUDS elements with varied soil properties and vegetation covers in an urban area. To that end, a total of 18 soil water content reflectometers to measure soil temperature and moisture were implemented in three SUDS components (i.e., densely vegetated rain garden, sparsely vegetated rain garden, and a front lawn with a grass vegetation cover receiving stormwater from a roof through a drain into a soakaway) in the study area at different depths (5–20 cm). An area-velocity flowmeter was installed at the outfall of the catchment to monitor runoff from the SUDS system as well as from the impervious surfaces that include streets, parking lots, and walking paths. Preliminary assessment at the beginning of the freezing period (i.e., November and December) showed that the densely vegetated rain garden was less susceptible to frost formation (frost reached 15 cm depth; min. -1.6 °C) compared to the sparsely vegetated rain garden (20 cm frost depth; min. -3.8 °C at 15 cm). In the front lawn, on the other hand, frost penetrated down to 10 cm depth (the depth at which soil was monitored and the minimum soil temperature dropped to -5.4 °C). The preliminary results show that the SUDS system was very effective during summer/fall and successfully infiltrated a total of 58% (n=14) of the storm events, especially small events (< 2 mm). The runoff coefficient for the events that produced surface runoff ranged between 0.011 and 0.19 (n=24) with an average volume reduction of 92% of the incoming runoff. However, further assessment of the system’s efficiency in terms of volume and runoff reduction during winter is still needed.
The role of sediments on subduction dynamics and geometry: insights from numerical modeling
Authors: Brizzi Silvia , Becker Thorsten , Faccenna Claudio , Behr Whitney , van Zelst Iris , Dal Zilio Luca , van Dinther Ylona
Published: February 2023

It is widely recognized that sediments play a key role for subduction. For example, sediments subducted along the shallow seismogenic plate interface are thought to influence seismic coupling and the occurrence of megathrust earthquakes, as well as the morphologies of accretionary prisms. Due to their weakening and/or lubricating effect, subducted sediments are also thought to promote faster plate speeds. However, global observations are not clear-cut on the relationship between the amount of sediments and plate motion. Here, we use 2D thermomecanical models to investigate how incoming plate sediments can influence subduction dynamics and geometry. We find that thick sediments can promote slower subduction due to an increase of the shear stress along the plate interface as the accretionary wedge gets wider, and a decrease of slab pull as more buoyant material is subducted. Our results also show that the larger interface shear stress and slab buoyancy due to thick sediments increase the slab bending radius. This study offers a new perspective on the role of sediments on large-scale subduction dynamics, suggesting that sediment buoyancy and wedge geometry might also affect plate motion and geometry.
Event-oriented observation across scales and environmental systems: MOSES started operation.
Authors: Weber Ute , Schuetze Claudia ,   MOSES-Team
Published: February 2023

The novel observing system „Modular Observation Solutions for Earth Systems (MOSES)“, is an initiative of the Helmholtz Association of German Research Centers that aims at investigating the interactions of short-term events and long-term trends across environmental systems. MOSES is a mobile and modular infrastructure and its component measuring systems are managed by the participating research centers. By quantifying energy, water, nutrient and greenhouse gas states and fluxes during events such as heat waves, droughts, heavy precipitation, floods, rapid thaw of permafrost or of ocean eddies, and subsequently along the related event chains, the system delivers data to examine potential long-term impacts of these events and to gain a better understanding of extreme events that are expected to increase in frequency and intensity in a changing climate. In order to obtain comprehensive data sets, a cross-system approach is followed, covering the atmosphere, land surface and hydrosphere. These event-related data sets complement long-term and/or large scale data sets of established national and international monitoring programs and satellite data such as TERENO, ICOS, eLTER, SENTINEL, etc. After a 5-year setup period, MOSES was successfully put into operation in 2022 (Weber et al., 2022, https://doi.org/10.1175/BAMS-D-20-0158.1).While long-term trends are typically assessed with stationary observation networks and platforms specifically designed for long-term monitoring, proven event-oriented observation systems and strategies are still missing. Event-oriented observation campaigns require a combination of a) measuring systems that can be rapidly deployed at “hot spots” and in “hot moments”, b) mobile equipment to monitor spatial dynamics in high-resolution, c) in situ measuring systems to record temporal dynamics in high-resolution, and d) interoperable measuring systems to monitor the interactions between atmosphere, land surface and hydrosphere. We will present the observation system and the observing strategy on examples from two past test campaigns: 1) The “Swabian MOSES campaign” of 2021 that captured the formation and evolution of supercells, hail and heavy precipitation and the resulting local flash floods (Kunz et al., 2022, https://doi.org/10.3389/feart.2022.999593). 2) The MOSES campaign of 2019 that captured the historical low flow situation along the Elbe River and into the German Bight (e.g., Kamjunke et al., 2021, https://doi.org/10.1002/lno.11778). As an outlook, upcoming national and international campaigns and potential future deployments will be presented.
Enhancement of drought monitoring by means of soil sampling and drone-based multispectral sensing
Authors: Sofia Giulia , Sinatra Martina , Tarolli Paolo , Zaccone Claudio
Published: February 2023

Monitoring crop physiological responses to drought is crucial to understand progressive impacts on food production and identify resilient and sustainable irrigation practices. Although many climate research experiments provide valuable data, long-term measurements of soil properties and plant characteristics at the field scale are not always affordable. We combined drone-based multispectral remote sensing with measurements of soil properties over multiple pilot farms, where soil sampling was performed for each plot during the drone survey. Our goal was to determine if drone-based indices capture drought stress responses of different crops (maize and sugar beet) and whether responses are affected by soil physical and chemical characteristics (e.g., texture, density, porosity, moisture, pH, electrical conductivity, organic carbon and total nitrogen contents, availability of micro and macro nutrients). Significant relationships were found between vegetation indices and soil features for different crop types. Differences found at the field scale were related mostly to organic carbon content and resulted in heterogeneous responses to irrigation practices. Our spatial variability analysis pointed out an overall homogeneous response for areas submitted to severe and moderate drought having similar soil properties, independently of the crop type. More investigation is needed to address the possible effect of local practices (e.g., fertilization, amendment, tillage) at the field scale. The feasibility of carrying out systematic drone flights coincidentally or close to-ground campaigns will reveal the consistency of the observed spatial patterns in the long run.
Simultaneous detection of long continuing current lightning with space and ground-based detectors
Authors: Camino-Faillace Pablo A. , Pérez-Invernón Francisco J. , Gordillo-Vázquez Francisco J. , Neubert Torsten , Reglero Víctor , Ostgaard Nikolai
Published: February 2023

Long continuing current (LCC) lightning flashes contain a discharge in which a continuing electrical current flows for more than 40 ms. They represent about 10% of the total cloud-to-ground lightning flashes and have been associated with lightning-ignited wildfires. LCC flashes can be detected by different terrestrial- and space-based instruments. However, those instruments simultaneously detect all kinds of lightning across the globe, including those with long continuing current, which hinders the analysis of LCC-only events.We present a method to match every single flash from the Geostationary Lightning Mapper (GLM), the Atmosphere-Space Interactions Monitor (ASIM) and the Earth Networks Total Lightning Network (ENTLN) by using a proximity index. In turn, we analyze the optical signal of LCC flashes simultaneously detected by GLM and ASIM.According to preliminary results, we found an average of 15 LCC events per month in the continental United States simultaneously detected by the three mentioned sensors (GLM, ASIM and ENTLN). Moreover, this method can be used to match other atmospheric electricity phenomena simultaneously detected by different ground and/or space-based instruments.
Modeling and measuring glacier-wide snow redistribution at Hintereisferner
Authors: Voordendag Annelies , Goger Brigitta , Prinz Rainer , Sauter Tobias , Kaser Georg
Published: February 2023

The representation of the snow cover dynamics (including accumulation, redistribution, and compaction), due to their impact on the snow-albedo feedback, poses the central deficiency in distributed mass balance models for most temperate and land-terminating glaciers. Data quantity and quality both from ground measurements and from remote sensor systems have not yet been sufficient to resemble these actual processes on a glacier scale until now. This limits the calibration and evaluation of distributed mass balance models.Yet, we installed a permanently terrestrial laser scanning (TLS) system at the Hintereisferner glacier (Ötztal Alps, Austria), which provides a daily digital elevation model (DEM). These DEMs with an accuracy of about ±10 cm can serve as calibration and validation data of distributed glacier mass balance models.We present a case study of snow cover dynamics between 6 and 9 February 2021. Snow fall of approximately 50 cm was registered and moderate wind speeds were measured on these days. Furthermore, wind-blown snow and small avalanches are visible on the webcam pictures. Three high-quality DEMs (e.g. no clouds) were taken on these days. The snow fall and snow redistribution thereafter can be reconstructed with the these DEMs and data from automatic weather stations on Hintereisferner and its surrounding slopes. To support the process analysis, we simulated the case study days with the Weather Research and Forecasting model (WRF) with a high-resolution setup of dx=48m. A recently implemented snow drift module allows to assess and understand wind-driven snow redistribution on the glacier.This high-resolution set-up, both on the observational and modelling side, allows an improved understanding of snow distribution over glaciers and has the potential to be applied at other glaciers as well.
Extension of the software toolkit GROOPS by satellite laser ranging
Authors: Suesser- Rechberger Barbara , Mayer-Guerr Torsten , Dumitraschkewitz Patrick , Tieber-Hubmann Cornelia , Krauss Sandro
Published: February 2023

The Gravity Recovery Object Oriented Programming System (GROOPS) is meanwhile a highly sophisticated and well accepted tool in the scientific community which enables the user to perform core geodetic tasks. The key features of the software include gravity field recovery from satellite and terrestrial data, the processing of global navigation satellite system (GNSS) constellations and ground station networks and the determination of satellite orbits from GNSS measurements. In the course of the continuous development of GROOPS, we will extend the software by satellite laser ranging (SLR) as an additional feature. Satellite laser ranging offers the possibility to measure distances from low earth orbiting (LEO) satellites with an accuracy in the mm and cm range. A major advantage of this observation technique is that only a passive space technology, called laser retroreflectors are required onboard. Satellite laser ranging can be used as a tool for independent validation of precise determined LEO satellite orbits. Thus, through the extension of GROOPS by SLR we will also be able to perform a validation of our own determined satellite orbits, which we publish regularly. In this work we will give an overview of the integration of the SLR processing, and how corrections regarding the satellites centre of mass, antenna offsets, laser retroreflector offsets and satellite/station specific range biases are handled. Additionally, we will show the orbit validation results of several satellite missions with laser retroreflectors onboard.
Stepwise calibration of age-dependent biomass in the Integrated Biosphere Simulator (IBIS v2.6) model
Authors: Ma Rui , Zhang Yuan , Ciais Philippe , Xiao Jingfeng , Liang Shunlin
Published: February 2023

The carbon sequestration capacity of forest ecosystems is closely related to their stand age. However, land surface models (LSMs) usually omit the impact of stand age and calibrate the carbon fluxes from equilibrated states after the model spin-up followed by a perturbation of biomass only resulting from environmental factors such as CO2 and climate. The mismatch between modelled and real forest stand ages will bring large uncertainties in the simulation of carbon stocks and the projection of future carbon sequestration potential. In this study, we implemented and calibrated age-dependent biomass in the Integrated Biosphere Simulator (IBIS) model using forest age and biomass information at 13 representative forests across the world. Specially, to avoid error compensation in model processes, we developed a stepwise optimization framework that integrates remotely sensed gross primary productivity (GPP), leaf area index (LAI), and age-dependent biomass curves into the IBIS model in three calibration steps. The modified adaptive surrogate modelling optimization (MASM) algorithm was applied in our framework to accelerate the parameterization based on surrogate modelling. Compared with the original model, our improved model leads an average error reduction (AER) in GPP, LAI and biomass by 23.7%, 28.6% and 65.7%, respectively, after each calibration step. The new parameters decreased the mean annual net biomass productivity (NBP) during 2000-2020 by 23.1 and 35.7 gC/m2/year in the mixed forests and deciduous broad-leaved forests, respectively, and increased NBP by 36.1-68.7 gC/m2/year in coniferous forests and evergreen broad-leaved forests. Our work highlights the necessity of considering forest age in LSMs, and provides a new framework for better calibrating LSMs under the constraints of multiple satellite products.
A model-based approach to assessing the balance between groundwater recharge and use in Kumamoto Area, southern Japan
Authors: Kawasaki Masatoshi , Tawara Yasuhiro , Fukuoka Yo-ichi , Simada Jun
Published: February 2023

For sustainable use of groundwater, it is important to know the water balance of groundwater as land and water use changes for working with stakeholder collectively.
In order to understand these issues, a distributed hydrological model that includes the key processes of the regional hydrological system is considered to be a powerful tool, as it enables us to understand the impact of human activities at any given site.
In the Kumamoto region, which is almost 100% dependent on groundwater for drinking water, there have been attempts to understand groundwater flow and water balance qualitatively and quantitatively (Ministry of Land, Infrastructure, Transport and Tourism (2011), Rahman et al. (2021)), and uncertainty quantification of model parameters (Kawasaki et al.(2022)).
These models are expected to be applied to understanding the impacts of changes in land and water use, but it is not easy to conduct an evaluation of impacts to derive practical actions, as it requires a large number of calculations with many possible combinations of scenarios, including the area to be changed and the degree of change.
Therefore, in this study, with the objective of understanding the impact of possible anthropogenic and environmental changes on the groundwater balance, the areas that are important for the assessment target were first identified by sensitivity analysis. Then, based on confirmation that no extreme phenomena occur in the identified important areas and in combination with each parameter, an evaluation of the impact was attempted by using what-if simulations, and the results of these simulations are reported.
How meteorological and cloud processes affect water isotopes in a tropical rain shadow region?
Authors: Sheena Sunil Nimya , Sengupta Saikat
Published: February 2023

Stable water isotopes can be used as natural tracers of various physical processes in the atmospheric water cycle. The isotopic signal is modulated by several meteorological and cloud microphysical processes such as moisture recycling, advection, condensation, evaporation, etc. The interaction of these processes with water isotopes are often complex in tropical orographic regions especially in the lee side of the mountains which are, in general,  rain shadow regions. Disentangling the roles of these process in the water isotope variability is very important considering these regions host a gamut of natural archieves from which decadal to centennial scale climate have been reconstructed earlier. Towards this, the current study presents daily rain and ground level vapour isotope observations in a tropical Indian rain-shadow region.The analyses shows that mesoscale convections affect both water isotope values significantly. A considerable isotopic exchange between rain and vapour is also noted in the sub cloud layer suggesting a strong control of sub cloud processes in the isotope values. Using an 1-D model, the role of all these process in the isotope values are further evaluated.     
Recommendations for microgravity campaigns and insight into volcanic subsidence and uplift gained from microgravity data at Askja, Iceland between 1988 - 2022
Authors: Koymans Mathijs , de Zeeuw-van Dalfsen Elske , Evers Läslo , Sepulveda Araya Josefa , Hooper Andy , Grapenthin Ronni , Ófeigsson Benedikt , Sigmundsson Freysteinn , Yang Yilin
Published: February 2023

In August 2021, Askja volcano in Iceland experienced  a sudden onset of rapid uplift that followed decades of continuous subsidence. We review the extensive microgravity record from Askja, revisiting data recorded between 1988 and 2017, and presenting new microgravity data from 2021 and 2022 that were collected after the uplift had started. Based on our findings, we provide a comprehensive set of recommendations that should be followed for optimal microgravity data collection and treatment in volcano monitoring. Without such standards, it becomes increasingly challenging to interpret the microgravity results in terms of volcanic processes. At Askja, from 1988 – 2016, exponentially decaying surface subsidence was accompanied by a microgravity decrease, potentially signaling the contraction of its magma chamber, eviction of magma to deeper levels, or other density-decreasing processes. Following this, between 2016 and 2021, a gravity increase occurred in the center of the caldera which effectively annuls the microgravity decrease detected between 1988 and 2016. This increase took place either during subsidence or leading up to and during the uplift, and may potentially be explained by mass accumulation below the caldera. After August 2021, gravity changes follow the free-air gradient, despite continuing deformation with a total uplift of up to 40 cm, suggesting subsurface density decreases as a driving process. Such a process could be envisaged as the previously emplaced intrusion before 2021 that is now undergoing magma vesiculation, is causing a change in the hydrothermal system, or represents the replacement of dense basaltic magma with less dense rhyolitic magma. However, uncertainties for these data are large (50μGal) and small mass intrusions contributing to the uplift may remain undetected. The driving mechanism for the uplift remains enigmatic and future microgravity campaigns will help shed light on its nature.
Using the Calorespirometric Ratio to investigate the metabolism of a growing microbial community dominated by Firmicutes in glucose-amended soil
Authors: Endress Martin-Georg , Chen Ruirui , Blagodatskaya Evgenia , Blagodatsky Sergey
Published: February 2023

Soil microorganisms rely on coupled fluxes of carbon and energy from the decomposition of organic substrates to fuel their maintenance and growth requirements. This complex coupling depends on environmental conditions as well as the specific metabolic reactions carried out by the microbial community, but our understanding of the principles governing these dynamics is still limited. The joint analysis of both matter and energy fluxes and in particular the linkage of the microbial carbon and energy use efficiencies (CUE and EUE) during substrate turnover have the potential to elucidate the underlying metabolic pathways. However, such evaluations remain rare.In this study, we present measurements of heat and CO2 release from soil after batch input of glucose along with estimates of microbial biomass and community composition. The results reveal a temporal variation in the ratio of heat to CO2 release (Calorespirometric Ratio, CR) that is inconsistent with simple aerobic decomposition of the substrate. In addition, we find that the dynamics are dominated by the growth of Firmicutes, whose relative abundance increases from 2 percent of initial biomass to almost 50 percent over the course of the incubation.To interpret these findings, we developed a dynamic model of carbon and energy fluxes during growth on glucose. The model simulates aerobic respiration as well as anaerobic fermentation to lactate and acetate depending on the time-varying availability of O2 and accounts for activation of the microbial population after initial dormancy. Model simulations capture the complex experimental CR pattern and suggest a gradual depletion of available O2 and a concurrent shift to anaerobic pathways as the main driver of the dynamics. Given the widespread adaptation to anaerobic conditions found in prevalent members of the Firmicutes, this interpretation is consistent with the observed dominance of the phylum. Notably, model variants of lower complexity that do not include fermentation or increasing microbial activity fail to appropriately reproduce the measured CR and biomass.These results highlight the potential of the joint analysis of matter and energy fluxes in a combined experimental and modeling approach. The evolution of CR over time revealed the presence of complex dynamics even in the simple case of glucose-amended soil samples and provided constraints on the metabolic processes behind those dynamics that align with the available biomass and community composition estimates. By considering the balance of multiple metabolic pathways as well as the concept of microbial activity, our findings offer a more detailed description of temporal microbial carbon and energy use that goes beyond the assumption of constant CUE and EUE. Such an approach will be essential for the investigation of more complicated transformations of organic matter in soil.