bluuebunny/crossref_metadata_2025 huggingface dataset:
Glacier changes and their impact on water resources in the Qilian Mountains, High Mountain Asia, 1970s to2020
Authors: Cao Bo , Hock Regine
Published: February 2023

The Qilian Mountains, located along the northeastern margin of the Tibetan Plateau, are in a transitional zone of climate types. Changes in glacier runoff in this region are important for the availability of water resources in arid regions of Northwest China. Combining multi-period remote sensing images and historical data, the distribute and changes in the area of glaciers in the region were updated and the changes in the glacier surface elevation were determined using geodesy methods. The glacier mass balance and glacier meltwater data were reconstructed using the glacier mass balance model. A continuous and accelerating shrinkage indicated substantial area loss between the 1970s and 2020 (516.89 km2, ~26%) and glacier thinning of -0.37±0.04 m a-1 between 2000 and 2014 were identified. In general, glaciers in the eastern Qilian Mountains are less distributed and retreat faster, whereas those in the western Qilian Mountains are more distributed and retreat relatively slowly. The glacier mass balance of each basin in the Qilian Mountains showed an increasingly negative trend. However, due to the shrinking in glacier area and increasing in precipitation, the contribution of glacial meltwater to river runoff turns to decreasing trend around 2000. As the glaciers continue to retreat, the glacier regulation is becoming weakening, which is alarming, with respect to future changes in runoff and related disasters.
Soil carbon storage as affected by the conversion from croplands to pastures with holistic grazing in Eastern Denmark
Authors: Sørensen Klara , A. O’Keeffe Joanne , Bækgaard Eriksson Kari , W. Müller Carsten
Published: February 2023

Agricultural management is strongly affecting soil organic carbon (SOC) stocks and cycling in half the world’s habitable land areas. Regular cropping with annual crops is known to considerably reduce soil carbon stocks, with detrimental effects to soils’ fertility and heightening atmospheric greenhouse gas concentrations. Compared to croplands, grasslands and pastures generally store more SOC. Thus, the conversion of croplands into pastures and grassland can be beneficial for soil carbon storage. The objective of the present study was to elucidate how the conversion of a cropland into holistically grazed pastures affect SOC storage. To test differences in soil OC we used a space for time approach and sampled a chronosequence consisting of a 4-year-old pasture, 10-year-old pasture and a nearby crop-field near Ringsted, Denmark. Mean annual temperature is 8.9°C and annual precipitation 695 mm, all three sites classified as a sandy loam according to Danish soil texture maps. Sampling was done in late September and early October, where 10 soil cores to 40 cm depth were taken from each field and split into samples of 0-10, 10-25 and 25-40 cm. SOC, total N, pH and bulk density (BD) was determined for each sample. SOC concentrations and stocks were calculated by equivalent soil mass approach, and comparisons of SOC and BD between managements done through linear mixed modelling, to account for spatial autocorrelation between samples from one soil core. Results show that both pastures have significantly higher SOC concentrations and lower bulk densities than the crop field. The 10-year-old pasture showed slightly higher SOC concentrations and stocks in the top 10 cm, but this difference was not statistically significant. No other significant differences were found between the two pastures. This suggests that SOC and BD changes happen rapidly after conversion from croplands to pastures, and a steady low build up of additional soil OC occurs after a certain threshold of SOC stocks is reached. However, as we used a space for time approach, one can not fully rule out differences in historic land-use and thus certain similarities between the pastures before the conversion compared to the sampled cropland. 
A multivariate approach to combine general circulation models using graph cuts
Authors: Schmutz Lucas , Thao Soulivanh , Vrac Mathieu , Mariethoz Gregoire
Published: February 2023

General circulation models (GCMs) are of extreme importance to making future climate projections. Those are used extensively by policymakers to manage responses to anthropogenic global warming and climate change.To extract a robust global signal and evaluate uncertainties, individual models are often assembled in Multi-Model Ensembles (MMEs). Various approaches to combine individual models have been developed, such as the Multi-Model Mean (MMM) or its weighted variants.Recently, Thao et al. (2022) proposed a model comparison approach based on graph cuts. Graph cut optimization was developed in the field of computer vision to efficiently approximate a solution for low-level computer vision tasks such as image segmentation (Boykov et al., 2001). Applied to MMEs, it allows selecting for each gridpoint the best-performing model and produces a patchwork of models that maximizes performances while avoiding spatial discontinuities. Thus, it considers the local performance of individual models in contrast with approaches such as MMM or similar methods that use global weights.Here we propose a new multivariate combination approach of MMEs based on graph cuts. Compared to the existing univariate method, our approach ensures that the relationships between variables, that are present in GCMs, are locally preserved while providing coherent spatial fields. Moreover, we measure the local performance of models using the Hellinger distance between multi-decadal distributions. This allows a combination of models that is not only indicative of the average behavior (e.g. mean temperature or mean precipitation) but of the entire multivariate distribution, including more extreme values that have a high societal and environmental impact.REFERENCES Boykov, Y., Veksler, O., & Zabih, R. (2001). Fast approximate energy minimization via graph cuts. IEEE Transactions on Pattern Analysis and Machine Intelligence, 23(11), 1222–1239. https://doi.org/10.1109/34.969114Thao, S., Garvik, M., Mariethoz, G., & Vrac, M. (2022). Combining global climate models using graph cuts. Climate Dynamics, February. https://doi.org/10.1007/s00382-022-06213-4
Nowcasting localized heavy precipitation using a multi-parameter phased array weather radar (MP-PAWR) and a 3D recurrent neural network.
Authors: Baron Philippe , Kawashima Kouhei , Kim Dong-Kyun , Hanado Hiroshi , Maesaka Takeshi , Satoh Shinsuke , Kawamura Seiji , Ushio Tomoo
Published: February 2023

Temporal extrapolation of radar observations of precipitation is a means of nowcasting sudden localized heavy rains, i.e., restricted convective rains on a spatial scale of less than 10 km and a lifetime of a few tens of minutes. Such nowcasts are necessary to set up warning systems to anticipate damage to infrastructure and reduce the fatalities these storms cause. It is a difficult task due to the storm suddenness, their restricted area, and nonlinear behavior that are not well captured by current operational systems, even for a lead time of only 10 minutes. Often, conventional approaches use radar observations with 5 min resolution and a Lagrangian advection based extrapolation model with a poor description of the vertical dimension. In this study, we use a new Multi-Parameter Phased-Array Weather Radar (MP-PAWR) with a temporal resolution of 30 sec and a 3D recurrent neural network to improve 10-minute nowcasts of sudden localized rains. The MP-PAWR has been operational in Japan (Saitama prefecture) since 2018. The nowcast model is a supervised neural network trained with adversarial technique. It considers the 3D volume surrounding the instrument up the height of 10 km and the polarimetric information of the measurement.  Improvements with conventional nowcasting techniques will be discussed with some typical examples.
High resolution soil moisture drought monitoring over Luxembourg
Authors: van Hateren Theresa C. , Chini Marco , Matgen Patrick , Teuling Adriaan J.
Published: February 2023

With the emergence of accurate high resolution remotely sensed datasets of hydrological variables, opportunities arise to study hydrological processes at an unprecedented scale and resolution. We took this opportunity to study spatiotemporal drought patterns over the country of Luxembourg. A daily 100x100 m2 soil moisture dataset based on the VanderSat technologya will be analysed in conjunction with a 6-day 60x60 m2 soil moisture dataset retrieved from Sentinel-1 data (Pulvirenti et al., 2018; van Hateren et al., 2021), and the Copernicus 1x1 km2 daily soil moisture product based on the TU Wien algorithmb. First of all, the consistency between the different products will be tested, as well as their ability to resolve small-scale variability in soil moisture. Then, the soil moisture products are compared to in situ soil moisture data, meteorological data and vegetation indices during major droughts in the last decade (2018, 2022). We will compare small scale spatial and temporal patterns of drought indices with land use, geology and elevation to see how the indices developed during these droughts and how they depend on the local landscape.ahttps://data.public.lu/en/datasets/soil-humidity-in-luxembourg-2002-2022/bhttps://land.copernicus.eu/global/products/ssmPulvirenti, L. et al., ‘A Surface Soil Moisture Mapping Service at National (Italian) Scale Based on Sentinel-1 Data’, Environmental Modelling & Software 102 (April 2018): 13–28, https://doi-org.ezproxy.library.wur.nl/10.1016/j.envsoft.2017.12.022.van Hateren, T.C. et al., ‘Optimal Spatial Resolution of Sentinel-1 Surface Soil Moisture Evaluated Using Intensive in Situ Observations’, in 2021 IEEE International Geoscience and Remote Sensing Symposium IGARSS, 2021, 6311–14, https://doi-org.ezproxy.library.wur.nl/10.1109/IGARSS47720.2021.9553041.
Dynamic magma movements beneath the Axial Seamount revealed by Rayleigh-wave Admittance Method
Authors: Wang Li , Ruan Youyi
Published: February 2023

Investigation of the dynamic magma movement beneath the volcanos could provide critical information about the mechanism of volcanic eruption and therefore enhance the accuracy of eruption forecast.  Axial Seamount is an active submarine volcano located at the intersection of the Juan de Fuca Ridge and the Cobb hotspot.  Through its submarine surveillance network of Ocean Observatories Initiative (OOI), we observed magmatic activities that occurred before and during its latest eruption on April 24, 2015, as well as the following unrest events from the temporal variations of shear-wave velocity beneath Axial Seamount. In this study, we applied the Rayleigh-wave admittance method, which uses the frequency-domain transfer function between seismic displacement and water pressure, to invert for shear-wave velocity changes beneath the submarine seismic stations.  The results illustrated that a large magma upwelling event happened beneath the AXEC2 (southeastern caldera of Axial Seamount) several weeks prior to its 2015 eruption, implying the magma movement through a pathway near the southeastern caldera and possibly triggered the subsequent eruption.  However, another magma upwelling event beneath the AXID1 station (southern caldera) between December 2016 and June 2017 occurred without triggering any noticeable eruption event. These magmatic activities demonstrate that the eruption of Axial Seamount is controlled by a complicated magma plumbing system.  The eruption probably depends on not only the magma influx but also the status of the plumbing system and the overlying crustal layer.  With the Rayleigh-wave admittance method and the real-time data from the OOI network, we can continuously monitor the status of Axial Seamount and provide more information for the next eruption.
Evolutionary 3D Vs crustal model for Central Apennines
Authors: Bianchi Irene , Menichelli Irene , Chiarabba Claudio
Published: February 2023

Detailed 3D elastic crustal models are of fundamental relevance to many applications in Geosciences, from geodynamic modelling, to simulation of seismic wave propagation and seismic engineering. However, most of the recent models suffer from two main drawbacks: (1) they are often obtained from interpolation of local 1D models; and (2) they cannot be easily updated, without recomputing the entire model (which, as a corollary, implies the availability of the complete data-set of raw seismic data). The first drawback leads to mainly oversmoothed models on the horizontal scale, where vertical boundaries are not considered either in the 1D models and in the interpolated 3D model. The second disadvantage implies that current models are generally "static" and their updates require a research effort which is often not paying back in terms of outputs.In this study, we build the framework for an evolutionary elastic model of the Central Apennines. The starting data are represented by a huge data-set of local 1D S-wave velocity models (originally obtained from Receiver Function inversion). We invert such data-set following a Bayesian fusion approach, where the full posterior probability distribution (PPD) of the1D models is exploited to build the 3D elastic model (in absence of the full PPD information, estimators like mean posterior and standard deviation can also be used). The 3D distribution of elastic properties (i.e. a model) is represented by a 3D Voronoi tassellation of the study volume, where the number of 3D Voronoi cells and their positions are unknown. A Markov chain Monte Carlo (McMC) algorithm is used to sample the family of Voronoi models which "fit" the data adequately (here the "data" are the PPD of the 1D models). Our results are shown on a regular 5x5x5 km grid down to 100 km depth, and they are consistent with previous models in terms of difference in crustal structure between the Tyrrhenian and Adriatic side of the Apennines. The model shows which of the features are coherent between adjacent stations, and which areas are better resolved. Point of strength over previous models is the possibility of identifying  sub-vertical boundaries, that in a complex region of subduction and neo-formed crust are more likely than a horizontally layered structure. More complementary or additional data (in the form, e.g. of tomographic models or 1D models from dispersion curves) can be easily added to this model, to update it, as new data become available. In fact, new "data" can be either added to the full data-set or can be included modifying the PPD of the 3D Voronoi cells.
S2S rainfall forecast calibration in real-time for a dense network of hydropower catchments
Authors: Schepen Andrew , Bennett James , Pokhrel Prafulla , Robinson Kim
Published: February 2023

The continuing improvement of seasonal rainfall outlooks means they are now skillful enough to predict inflows to hydropower schemes and help to anticipate operational decisions. Hydro Tasmania, Australia’s largest generator of hydropower, is working with CSIRO to develop a long-range inflows prediction system for its 6 hydroelectric schemes. The schemes complement each other and are operated as a single system. The inflows predictions will be generated with conceptual hydrological models calibrated to a dense network of 563 sub-catchments. In this study, we develop a real-time S2S rainfall forecast capability for this network with forecasts updated as frequently as daily. We seek to establish a forecast post-processing model that generates high-resolution, spatially correlated ensemble rainfall forecasts from coarse-resolution climate model forecasts. We compare lagged ensemble forecasts from the Bureau of Meteorology’s new ACCESS-S2 seasonal forecasting model with burst ensemble forecasts from ECMWF’s SEAS5 model, eliciting the value of simple versus complex post-processing methods for coarse-scale calibration of the ensemble climate forecast. A random selection from k nearest-neighbours provides a template for disaggregation of each ensemble member to the required spatial and temporal resolution. To understand the skill available to the real-time forecasting system, we evaluate the historical performance of the system from 1981-2018. Skilful forecasts can be obtained for the next month after which the ensemble time series ought to revert to an unbiased climatology forecast. The calibration method can be highly computationally efficient, allowing parameters to be re-estimated in the process of generating each new forecast, thereby updating parameters with the most up-to-date forecast and observation data available. Combined with an efficient hydrological model, reliable rainfall forecasts can add value to antecedent hydrological conditions to provide more skilful forecasts of inflows for the season ahead.  
New opportunities to unravel the microarchitecture of soil organo-mineral associations by NanoSIMS using the upgraded Oxygen source
Authors: Höschen Carmen , Schweizer Steffen , Kögel-Knabner Ingrid
Published: February 2023

Organic matter (OM) and soil mineral constituents interact closely at the submicron scale forming structural units and providing biogeochemical interfaces. Soil structure itself plays a key role for carbon storage, microbial activity and soil fertility and pollutant mitigation. A better understanding to which extent biogeochemical processes and interactions in the soil are driven by the spatial arrangement of OM and mineral constituents requires advanced efforts to apply novel microspectroscopy approaches.NanoSIMS, allowing unique elemental and isotopic analyses at nanometer spatial resolution, provide valuable insights into the architecture of soil organo-mineral constituents and crucial processes taking place at the microscale.The instrument is equipped with two ion sources: the Cesium source (Cs+) convenient to detect ions related to organic matter distribution and the Oxygen source (O-) favourable to provide information on mineral phases or metals in samples. With a spatial resolution similar to the Cesium source and high stability, the upgraded radio frequency (RF) plasma Oxygen source  recently installed at the TUM is now best suited for novel analytical approaches to probe elemental and isotopic composition of soil organo-mineral constituents in soils at the microscale.We will show examples of how the two primary ion sources, single or correlatively applied, enable novel experimental designs in soil biogeochemistry. Novel combinations of the OM distribution (12C, 13C and 14N, 15N) detected by the Cs+ source with the distribution of e.g. Si, Al, Fe, Ca, Mg, K, and Na of minerals as revealed by the O- source are now possible.Post-processing tools for unsupervised clustering and supervised segmentation facilitate the comparison and quantitative analysis of the spatial architecture within intact soil structures. These ongoing developed tools can contribute to the extent of our understanding of biogeochemical processes taking place at organo-mineral and mineral-mineral interfaces in soil systems at the microscale.
Dating and characterizing carbonate rocks in Upper Permian reef-dolostone reservoir systems in Sichuan Basin, southwest China: implications for porosity evolution
Authors: Zheng Binsong , Zhou Renjie , Mou Chuanlong , Zhao Jianxin , Howard Daryl
Published: February 2023

Large gas fields are hosted in Upper Permian reef-dolostone bodies in Sichuan Basin, southwest China, among which the Puguang gasfield is the largest marine-carbonate gas system in China. The reservoir rocks are mainly composed of intensively dolomitized sponge-reefs constructed within platform margin reef facies in northern Sichuan Basin. Although major reservoir spaces consist of intercrystal pores, dissolved pores and vugs, the knowledge regarding the evolution of porosities is still limited. Using multiple methods, this study focuses on characterising different phases of carbonates (calcite and dolomite) to understand the dolomitization model and porosity evolution of the Upper Permian Panlongdong reef cropped out in northeastern Sichuan Basin. Two-dimensional high-resolution visualization of element contents in reef dolostones was provided by synchrotron-radiation Micro X-ray fluorescence elemental mapping. O and Sr isotope analysis was carried out to trace the nature of fluids during dolomitization. Laser ablation ICP-MS U-Pb dating was performed on dolomite minerals and secondary calcite cements. Our results suggest that: (1) dolomitization of the reef occurred in the early Middle Triassic (~245 Ma) due to the downward reflux of hypersaline seawater rich in Mg2+, accompanied by a significant increase in porosity because of the selective dissolution of low-Mg calcites; (2) in the Late Triassic, continental collision between South and North China plates induced uplifting and formation of a large quantity of (micro)fractures in northern South China, followed by Sr-depleted freshwater passing through the reef, leading to precipitation of secondary calcite cements (~206 Ma).
Earthquake Magnitude Prediction Using a Machine Learning Model
Authors: Berman Neri , Zlydenko Oleg , Gilon Oren , Bar-Sinai Yohai
Published: February 2023

Standard approaches to earthquake forecasting - both statistics-based models, e.g. the epidemic type aftershock (ETAS), and physics-based models, e.g. models based on the Coulomb failure stress (CFS) criteria, estimate the probability of an earthquake occurring at a certain time and location. In both modeling approaches the time and location of an earthquake are commonly assumed to be distributed independently of their magnitude. That is, the magnitude of a given earthquake is taken to be the marginal magnitude distribution, the Gutenberg-Richter (GR) distribution, typically constant in time,or fitted to recent seismic history. Such model construction implies an assumption that the underlying process determining where and when an earthquake occurs is decoupled from the process that determines its magnitude.In this work we address the question of magnitude independence directly. We build a machine learning model that predicts earthquake magnitudes based on their location, region history, and other geophysical properties. We use neural networks to encode these properties and output a  conditional magnitude probability distribution, maximizing on the log-likelihood of the model’s prediction. We discuss the model architecture, performance, and evaluate this model against the GR distribution.
Advances and limitations in carbon and water cycle modeling using the Biome-BGCMuSo biogeochemical model in a Central European beech forest
Authors: Dobor Laura , Petrík Peter , Zavadilová Ina , Šigut Ladislav , Hidy Dóra , Fodor Nándor , Barcza Zoltán , Hlásny Tomas , Merganičová Katarína
Published: February 2023

Approximately 30% of anthropogenic carbon dioxide emissions are removed from the atmosphere annually by land-based carbon sinks, mainly forests. Extreme weather events such as droughts and heatwaves are expected to be more frequent and severe in the future affecting the carbon-water balance of ecosystems. Although empirical studies elucidate many of these processes, some questions cannot be addressed directly and require constructing in silico representations of real ecosystems. Process-based ecosystem models have recently received increased recognition due to their structural improvements and the increasing success of reproducing complex feedback mechanisms of carbon and water cycles.We used the Biome-BGCMuSo biogeochemical model to simulate pools and fluxes of carbon, water, and nitrogen in vegetation, litter, and soil on a daily scale. The model is under continuous development and in the last few years, the hydrological cycle submodel went through substantial improvements. We examined the model performance regarding water and carbon cycle simulation using the data from an ecosystem station covered by a circa 100-year-old unmanaged beech forest. The site is included in the FLUXNET global network of micrometeorological tower sites and is operated by the Global Change Research Institute of the Czech Academy of Sciences. The extensively tested model can help to understand complex feedback mechanisms under drought events as well as future climatic conditions and estimate future carbon sink potentials in Central Europe. In particular, we (i) evaluated the model performance using biomass, leaf area index (LAI) measurements, five-year-long eddy-covariance measurements of net ecosystem exchange (NEE) and evapotranspiration (ET), (ii) developed an efficient benchmark framework that highlighted structural and/or functional errors in the model, (iii) analyzed the simulated carbon and water cycle under drought events (consecutive dry days) occurring different time of the year and (iv) projected the effects of climate change on the forest carbon and water cycle up to 2100 using climate change scenarios from the FORESEE climatological dataset.We found that the simulated biomass and LAI values are in the range of the observations, NEE and ET are overestimated by 5% and 11% during the vegetation period, respectively. Simulation runs assuming 30-days drought events at different months in five different years caused immediate NEE decrease compared to simulations without drought events. We found the largest NEE difference (up to 10% on the average of five years) in the cases when the drought occurred in July, August, or in September. Simulations driven by climate change scenarios showed that NEE is expected to increase by the of the century, while the ET does not show any significant change in the future. 
Seasonal evolution of near surface atmospheric temperatures at Jezero as measured by the MEDA instrument on Mars 202
Authors: Munguira Asier , Hueso Ricardo , Sánchez-Lavega Agustín , De la Torre-Juarez Manuel , Martínez Germán , del Río-Gaztelurrutia Teresa , Smith Michael , Lemmon Mark , Rodríguez-Manfredi Jose Antonio , Lepinette Alain , Sebastián Eduardo , Banfield Donald
Published: February 2023

We use data from the MEDA instrument on Mars 2020 to study the evolution of atmospheric and surface temperatures at Jezero. The measurements correspond to four height levels from the surface to ~40 m and together they allow us to examine multiple aspects of the near-surface meteorology at Jezero. We extend the analysis of near-surface temperatures of Munguira et al. (JGR:Planets 2023), which covered the period from Ls 13º to Ls 203º, over a full Martian year. We show the seasonal evolution of temperatures, including temperature fluctuations and thermal gradients, which are affected by the properties of the terrain traversed by Perseverance. We will focus on a physical description of the thermal processes that take place in the Convective Boundary Layer at Jezero. We compare near-surface temperatures with the atmospheric opacity around-the-clock retrieved by Smith et al. (2022) and with daily averages of optical depth measured by MastCam-Z (Bell et al. 2022). After Ls 203º, atmospheric waves coming across Jezero predicted by atmospheric models are expected to contribute to shaping temperatures producing thermal oscillations on time-scales of a few sols. This effect is accompanied by an enhanced variability of atmospheric opacity and both effects contribute to produce a higher variability on temperatures. References:[1] Munguira, A. et al. (2023). Near Surface Atmospheric Temperatures at Jezero from Mars 2020 MEDA Measurements. JGR: Planets.[2] Smith, M.D. et al. (2022). Diurnal and Seasonal Variations of Aerosol Optical Depth Observed by MEDA/TIRS at Jezero Crater, Mars. In Seventh international workshop on the Mars atmosphere: Modelling and observations (pp. 14-17).[3] Bell, J.F. et al. (2022). Geological, multispectral, and meteorological imaging results from the mars 2020 perseverance rover in jezero crater. Science Advances, 8 (47), eabo4856. doi: 10.1126/sciadv.abo485
Slow Earthquakes and the Spectrum of Fault Slip Modes: A View From the Lab
Authors: Marone Chris
Published: February 2023

A central goal of this work is to understand the extent to which fault friction vs. pore fluids and other factors is the cause of slow earthquakes and the spectrum of fault slip behaviors. Slow earthquakes and quasi-dynamic modes of fault slip such as tremor and LFEs have now been observed in essentially every tectonic setting, which suggests that the underlying mechanism(s) are generic rather than specific to a particular fault setting, rock type, or tectonic regime. Here, I discuss lab data that illuminate the mechanics of slow slip. I focus on frictional stick-slip failure events, the lab equivalent of earthquakes, that reproduce slow slip and the full range of slip behaviors observed on tectonic faults.  These studies document repetitive slip events and the complete lab seismic cycle for the full spectrum of slip behaviors from aseismic creep to slow slip and aperiodic elastodynamic failure. Working with data for repetitive slip events is critical for understanding the underlying mechanics. In the lab, we also document the rate of frictional weakening with slip kc = σn (b-a)/Dc  ––the so-called critical stiffness–– where σn is fault normal stress, (b-a) is the friction rate parameter and Dc is the critical slip distance. We measure kc for the same conditions of the slow slip events by altering the machine loading stiffness. These works assess directly frictional instability theory, which predicts the slip stability transition when the elastic stiffness of the fault zone k equals the frictional weakening rate kc. The lab work confirms friction theory in relation to the transition from stable to unstable slip but it also reveals additional complexity showing that kc varies with slip rate. Several works now document the velocity dependence of kc(V) and its role in dictating slow slip in the lab. These works show complex behavior near k/kc ≈ 1 including slow slip, aperiodic failure and chaotic motion. I discuss these results in the context of basic questions that remain regarding how slow ruptures can propagate quasi-dynamically, at speeds far below the Rayleigh wave speed, and how tectonic faults can host both slow slip and dynamic earthquake rupture.
On the organization of passive shallow cumulus clouds
Authors: Marin Andrei , Vraciu Cristian-Valer
Published: February 2023

The shallow cumulus clouds are ubiquitous in the atmosphere, populating a large part of the subtropical oceans. They may play a strong climate feedback due to their cooling effect on the Earth atmosphere. As a result, a large number of studies investigated the organization of cumulus clouds and their interaction with the climate. However, the organization of passive shallow clouds and their impact on the atmospheric convection and climate change received very limited attention. In this work, we perform a series of large eddy simulations in order to investigate how the organization and the total cloud cover depends on the relative humidity of the environment. We show that although the active cumulus clouds only show a weak correlation with the relative humidity, the passive clouds are very sensitive to it. We show thus that the cloud cover of the shallow cumuli is very sensitive to the relative humidity which could be very important in the context of the climate change. Furthermore, we formulate a conceptual picture to explain the organization of passive shallow cumulus clouds.
Characteristics and mechanisms of global monsoon changes during the 4.2 ka BP event
Authors: Ning Liang , Wu Fen , Liu Jian , Liu Zhengyu , Yan Mi , Sun Weiyi
Published: February 2023

The 4.2 ka BP event is one of the most severe centennial-scale cold and megadrought events during the Holocene, with serious influences on the collapse of the Akkadian Empire, and many other old civilizations. Based on 173 proxy records across the global monsoon regions and isotope-enabled Community Earth System Model last millennium ensemble (CESM-iLME), a group of precipitation 18O reanalysis for the period 2 ka-5 ka BP were reconstructed through the hybrid gain analog offline ensemble Kalman filter (HG-AOEnKF) with the fast implementation framework of Last Millennium Reanalysis (LMR) paleoclimate data assimilation. The time series showed that the 4.2 ka BP event in all northern Hemisphere monsoon regions exhibits as monsoon weakening, but are not synchronous. Spatially, consistent with the proxy data, during the 4.2 ka BP event, the East Asian summer monsoon shows wet anomalies in the south and drought anomalies in the north, and the North African monsoon, South Asian summer monsoon, and North American monsoon show unified drought anomalies. While, all three southern Hemisphere monsoon, i.e., South American monsoon, Australian monsoon, South African monsoon, show wet anomalies during the 4.2 ka BP event. Based on model simulations, it is found that the potential mechanism behind the 4.2ka BP event is the multi-century-scale fluctuations in SSTs across the North Atlantic and AMOC strength, superimposed on the steady decline in SSTs and AMOC led by long-term changes of orbital forcing.
Effectiveness-assessment of nature-based flood mitigation using networked, low cost DIY environmental monitoring from FreeStation
Authors: Burke Sophia , van Soesbergen Arnout , Mulligan Mark
Published: February 2023

FreeStations are mature low-cost, networked, DIY environmental sensors and data loggers, developed since 2014  and now deployed around the world.  Build instructions are open source at www.freestation.org and based on high availability, low cost but accurate and robust components (with builds typically 3% the parts-cost of an equivalent proprietary monitoring systems).  This allows investment in a network of environmental loggers at the cost of a single, proprietary logger.  FreeStations have been widely deployed in the DEFRA Natural Flood Management (NFM) national trials in the UK, and analytical methods developed to examine the performance of leaky dams, retention ponds, regenerative agricultural practices and other nature based solutions in mitigating flood risk at downstream assets.These deployments usually consist of FreeStation weather stations: recording rainfall volume, rainfall intensity, air temperature, humidity and pressure as well as solar radiation, wind speed and direction.  The rainfall volume and instantaneous intensity are the most important for NFM studies.  Alongside weather stations, FreeStation sonar-based stage sensors are used, alongside river profile scan from a FreeStation LIDAR, to monitor change in river discharge due to an NFM intervention, relative to discharge at a downstream asset at risk.  Readings are taken at 10-minute intervals over multiple years.A series of web based methods have been built as part of the FreeStation //Smart: platform to monitor and manage data from deployments and to analyse data to better understand flood mitigation by the key types of intervention.  In testing at more than 10 sites in the UK over a period of 2-3 years per site, large volumes of data have been collected at low cost and in support of local stakeholders during the H2020NAIAD and H2020ReSET projects.  The data indicate the importance of careful design in leaky debris dams, the limited impact of inline retention ponds and the significant capacity of low-till farming methods to mitigate downstream flooding.  The effectiveness of NFM depends upon the number and scale of interventions, the proportion of the discharge at the downstream asset at risk which they affect (i.e. the downstream proximity of the asset at risk) and the capital and maintenance costs of the interventions. Low-cost approaches to environmental monitoring will be critical for developing the evidence base needed to better understand what nature based solutions work, where for water.  Low cost, internet-connected devices are easy to monitor and maintain, low risk and capable of extensive deployment to address the challenge of geographical variability which means that the impacts of specific NFM interventions are highly site specific. 
Mafic Mineral Anomaly in the Ohm Crater of the Moon
Authors: Patel Shreekumari , Satyakumar Animireddi V , Solanki Paras , El-maarry Mohamed R
Published: February 2023

The 64 km wide Ohm crater is a complex impact crater located on the northern side of the lunar farside. In this study, we generated abundance maps for FeO and TiO2 as well as Spectral Parameter maps to determine the composition. Orthopyroxene and Clinopyroxene, two mafic minerals, are present in the Ohm crater, according to spectral analyses of M3 data. A geostatistical technique is used to optimize the variation trend of diagnostic characteristics across different sites. We noticed that Opx dominates the rest of the crater, while Cpx dominates the western portion of Ohm. Opx denotes sources from above and/or below the crust-mantle boundary, whereas Cpx suggests impact melt crystallization of an anorthositic target crust. The NASA mission GRAIL, which is specifically designed to study gravity anomalies, has found negative anomalies near the Ohm crater that may indicate a thicker crust beneath the crater. Unequal Bouguer gravity anomalies and negative anomalies have been found in the vicinity of the Ohm crater, but they are not clearly connected to the internal morphology. Surface morphological features have no connection to these anomalies of uneven gravity. In addition, the Bouguer gravity signature may be affected by pre-existing subsurface density structure, and post-impact events (such as magmatism), which could account for some of the observed scatter. The regional gravity anomaly also indicates low values in the Ohm crater, suggesting that the thicker crust and the source of the geochemical anomalies are at deeper levels. Strong negative anomalies are seen in the predicted residual gravity data close to the Ohm crater, which suggests low-density bodies at the crustal level. We propose that the pyroxenes are the end product of impact melt crystallization based on regional and residual gravity anomalies, compositional and mineralogical features of the Ohm crater, and geophysical data. Ejecta from the SPA, Orientale, and Mascon Hertzsprung basins, which may or may not have differed from impact melt formed during the Ohm impact event, should also be looked at when analyzing the distribution of mafic minerals throughout the crater. The GRAIL crustal thickness model-1 for the Ohm crater indicates a thicker crust, demonstrating that the mantle upliftment is not the underlying cause of the geochemical anomalies in this area.Acknowledgement: S. M. Patel and M. R. El-maarry acknowledge support for this work through an internal grant (8474000336-KU-SPSC).
ShakeMap-EU: an update on the shakemap service in Europe
Authors: Michelini Alberto , Faenza Licia , Cauzzi Carlo , Lauciani Valentino , Clinton John , Kästli Philipp , Haslinger Florian , Wiemer Stefan , Melis Nikolaos , Theodoulidis Nikolaos , Böse Maren , Weatherill Graeme , Cotton Fabrice , Giardini Domenico
Published: February 2023

We present the status of ShakeMap-EU, an initiative initially proposed in 2018 to: (i) provide an integrated archive of ShakeMaps at the European level built on EPOS Seismology (www.epos-eu.org/tcs/seismology) services & data products and modern community software; (ii) serve as a backup to authoritative ShakeMap implementations; (iii) deliver ShakeMaps for Euro-Mediterranean regions where no local capability is yet available. ShakeMap-EU products are accessible since mid-2020 at the web portal shakemapeu.ingv.it. Jointly governed by the institutions participating in the initiative, ShakeMap-EU is founded on voluntary institutional contributions and EC-funded projects. ShakeMap-EU has become a reliable European seismological service that can easily and consistently integrate authoritative models and workflows. The system is based on:  (a) the latest version of ShakeMap® (usgs.github.io/shakemap); (b) the earthquake information delivered by the EMSC (www.emsc-csem.org); (c) the earthquake shaking data distributed by ORFEUS (orfeus-eu.org/data/strong); (d) the ground motion models adopted within EFEHR (www.efehr.org) for mapping seismic hazard across Europe; (d) the official ShakeMap configurations of some of the most hazardous countries in Europe. Configuration of, and input to the system are managed via a GitHub repository that allows automatic / manual triggering and interaction by authorized users. ShakeMap-EU provides a collaboration framework and laboratory for seismological agencies to address the challenges posed by the heterogeneity of ground shaking mapping strategies across Europe and the need to promote homogenization and best practices in this domain. ShakeMap-EU is used in research projects as the test platform for novel international collaborative research: among recent examples are the ongoing enhancements towards an evolutionary hazard information system including real-time seismicity characterisation and information on earthquake-induced phenomena.
Plasma-Neutral Interactions in the Lower Thermosphere-Ionosphere: The need for in situ measurements to address outstanding questions
Authors: Sarris Theodoros ,   co-authors of the white paper for the decadal survey for solar and space physics 2024-2033
Published: February 2023

The lower thermosphere-ionosphere (LTI) is a key transition region between the Earth’s neutral atmosphere and plasma-dominated space. Interactions between ions and neutrals maximize within the LTI and in particular at altitudes from 100 to 200 km, which is the least visited region of the near-Earth environment due to enhanced atmospheric drag. The lack of in situ co-temporal and co-spatial measurements of all relevant parameters and their elusiveness to most remote-sensing methods means that the complex interactions between neutral and charged constituents in the LTI remain poorly characterized to this date. This lack of measurements, together with the ambiguity in the quantification of key processes in the 100 to 200 km altitude range, affect current modeling efforts to expand atmospheric models upward to include the LTI and limit current space weather prediction capabilities. In this talk, fundamental science themes in ionosphere-thermosphere physics and related societal and operational needs are outlined; past proposed implementation schemes to sample this transition region are reviewed; and recent efforts by ESA and NASA to highlight outstanding science questions in the LTI and the need for in situ measurements to address them are presented.
Sustainable increase of SOC stocks and nutrients in sandy subsoils by ameliorative fractional deep tillage (aFDT)
Authors: Gerriets Marisa , Leue Martin , Koszinski Sylvia , Sommer Michael
Published: February 2023

The sandy soils of Eastern Germany show a high gradient in soil organic carbon (SOC) between topsoil and subsoil. This is reflected in the low nutrient supply, water storage capacity and increased compaction susceptibility of the subsoil. In view of these productivity limitations, ameliorative fractional deep tillage (aFDT) was developed in the late 1950s.The aim of this subsoil melioration measure is to create shafts enriched with organic-rich topsoil material in the subsoil to remediate root restricting layers and promote accessibility of subsoil resources. At the same time, organic C sequestration is induced by mixing of subsoil material low in organic matter into the topsoil. The 50 cm deep and 7-15 cm wide shafts are created at 35-80 cm intervals by a special plough or modified loosener. Thereby, solid zones remain between the shafts to ensure stability and reduce the risk of re-compaction of the strip wise deep tillage.We studied three 37- to 43-year-old historical field trials representing a soil quality gradient near Müncheberg to investigate the long-term effects of aFDT on SOC accumulation as well as nutrient stocks in the subsoil and organic carbon sequestration in the topsoil. Besides the shaft, the topsoil, the area next to the shaft, the subsoil material below the shaft and reference topsoil without aFDT outside the trial plot were sampled. In total, 43 shafts were sampled.We found that the 50-75% of the original SOC was still preserved in the shafts. The shafts had significantly higher SOC contents (+286%) and nutrient contents (P+75%, K +33%, Mg +50%) compared to surrounding subsoils (E/Bw horizons). These results indicate that aFDT is an effective melioration method to increase the SOC and nutrient stocks.
Impact of parent material, pedogenesis and plant cover on various P forms in soils developed in the foreland of the Uisu glacier in the Eastern Pamir, Tajikistan
Authors: Suska-Malawska Malgorzata , Galka Witold , Gądek Bogdan , Korabiewski Bartosz , Mętrak Monika , Sulwiński Marcin , Kabała Cezary
Published: February 2023

Global models of ecosystem limitation maintain that in the early stages of pedogenesis, low nitrogen availability limits the earliest stages of primary succession. However, high-altitude arid and hyperarid areas are underrepresented in these models. Significantly, the areas combining aridity with glaciation/deglaciation processes (i.e. Himalayas, Eastern Pamir, dry Antarctic), where soil development and ecological succession are still challenging for research. Therefore, our studies focused on the deposition of various forms of phosphorus in soil chronosequence developed in the foreland of the Uisu glacier in the Eastern Pamir in relation to soil physiochemical properties and vegetation cover. Our previous studies performed on a sequence of terraces, alluvial cones, and terminal moraines developed later from the late Pleistocene in the foreland of the Uisu glacier showed extreme cold and dryness noticeably slowed down soil development in the area, even if permafrost was not preserved in the soil profiles. Thus, soil development, manifested in the transformation of physicochemical soil properties and diagnostic horizons, had very low intensity and led to relatively little spatial soil differentiation in the foreland. In the presented research, soils from the locations mentioned above were sampled, and a modified Hedley fraction extraction technique was used to separate phosphorus into (1) an easily bioavailable fraction extracted with NaHCO3 (NaHCO3- Pt), (2) a moderately bioavailable fraction extracted with NaOH (NaOH-Pt) and (3) a fraction unavailable for plants extracted with HCl (CHCl- Pt).Moreover, total nitrogen (TN), total carbon (TC) and total organic carbon (TOC) contents were analyzed in the samples with standard analytical methods. We found shallow P content in all studied soil samples. For the samples from the terraces with high vegetation cover, we found significant solid positive correlations between both bioavailable phosphorus fractions and TN (r2=0.78 for NaHCO3- Pt and r2=0.80 for NaOH-Pt, in both cases p<0.001);  and between these fractions and TOC (r2=0.49 for NaHCO3- Pt and r2=0.53 for NaOH-Pt, in both cases p<0.001). For the samples from the moraine located 14 kilometres from the glacier and covered with sparse desert plants, we recorded no significant correlations between any bioavailable fractions of phosphorus and TN or TOC. However, the fraction of phosphorus unavailable for plants (CHCl- Pt) was strongly positively correlated with TOC (r2=0.70, p<0.01). It seems that the availability of P depends more on the decomposition process of organic matter than on the biochemical mineralization of minerals. This work was supported by the Polish National Science Centre (Grant No 2017/ 25/B/ST10/00468)