bluuebunny/crossref_metadata_2025 huggingface dataset:
Detecting shallow precipitation from conical-scanning radiometer observations using a Random Forest model over the Netherlands
Authors: Bogerd Linda , Whan Kirien , Kidd Chris , Kummerow Christian , Petkovic Veljko , Leijnse Hidde , Overeem Aart , Uijlenhoet Remko
Published: February 2023

Over the past decades, spaceborne radiometers have proven to be valuable input to realize a global coverage of precipitation estimates. However, retrieving accurate shallow precipitation estimates from radiometers remains challenging. The signal related to precipitation formed close to the Earth’s surface is difficult to distinguish from dry weather, especially over land.  Despite the relatively low precipitation rates that are often associated with shallow precipitation, its persistent presence results in a significant contribution to the total amount of rainfall over the mid- and high latitudinal regions. Hence, correct identification is important.This study aimed to improve our understanding of the radiometric signatures of shallow precipitation from passive microwave observations by implementing a Random Forest (RF) model. RF is chosen because of its limited risk of overfitting and the ability to physically interpret the resulting model structure and parameters. The RF model is applied to brightness temperature observations from all channels onboard the Global Precipitation Measurement (GPM) Microwave Imager (GMI) during 2017-2020 over The Netherlands (52°N). A high-quality gauge-adjusted radar product is used as reference. The echo top height retrieved from the two radars in The Netherlands (Herwijnen and Den Helder) are used to classify the GMI footprints to either dry, shallow (<3km) or non-shallow (>3km) regime.Hyperparameter settings, such as the depth of the model, and choices such as the number of years the model is trained on or the threshold to classify footprint as dry, shallow, or non-shallow regime have a limited effect on the performance of the RF. In general, the model tends to wrongly classify dry footprints as wet (both shallow and non-shallow). The model showed a seasonal dependency, with the best performance in summer. Preliminary results also showed a strong seasonal effect when excluding all footprints within 40km distance of the coast. These results indicate that four different parameter sets representing each season are required. Furthermore, the specific years the model is trained or tested on are found to strongly affect its performance. Currently, additional variables (such as ERA5 freezing level, two-meter air temperature) and simultaneous observations from the GPM dual-frequency precipitation radar (DPR), are included to further improve and understand the performance of the RF model.
Seismic structure of the Cheb Basin from high resolution surveying – traveltime tomography results
Authors: Banasiak Natalia , Bleibinhaus Florian
Published: February 2023

In our study we investigate the subsurface velocity structure of the Cheb Basin (Czech Republic) based on shallow high-resolution 2D seismic data collected in the years 2014-2020. The Cheb Basin is a small intracontinental basin, located in the north-west part of the Bohemian Massif and at the western end of the Cenozoic Eger Rift. The basin and underlying crustal structure are the subject of the ongoing International Continental Scientific Drilling Program (ICDP) “Drilling the Eger Rift''. Our surveys aim to investigate the up to 350-m-thick Miocene and Quaternary sediments and the bedrock, made of Paleozoic Variscan units and post-Variscan granites.Four datasets were collected, each with a 480-m-long split-spread of single geophones at 2 m spacing. The 2014 dataset was acquired with a 10 m source interval, mainly with a weight-drop source and partly with a SISSY source, resulting in an almost 3 km long profile. The 2017, 2020 line 1 and 2020 line 2 datasets were shot with a buffalo gun at a 20 m source interval. Their lengths are 2 km, 0.8 km and 1 km respectively.We present the traveltime tomography output for all 4 profiles, which brings important information about the subsurface. The results give us insight into the velocities of the sediments, which in this area mainly range from 600 m/s to 2500 m/s. The bedrock is observed with velocities up to 4500 m/s and is present at a depth of around 250 m below the surface. This velocity information is complimented by the preliminary results of the ongoing reflection processing.
Access control and reporting at the Data Center for Deep Geothermal Energy
Authors: Schaming Marc , Fremand Alice , Turlure Mathieu , Schmittbuhl Jean
Published: February 2023

The CDGP [https://cdgp.u-strasbg.fr], Data Center for Deep Geothermal Energy, is a Research repository for deep geothermal data in Alsace (France) originating from academic observatories or industrial providers. It collects seismological (catalogues, waveforms, focal mechanisms), seismic, hydraulic, geological, and all data related to anthropogenic hazard from the different phases of a geothermal project, mainly from the exploration and development stages at Soultz-sous-Forêts, Rittershoffen and Vendenheim EGS geothermal sites. Data are verified, validated, and curated; they are then described with metadata following the ISO 191115/19139 standards and have owner-defined distribution rules associated with them. A persistent Digital Object Identifier (DOI) is associated with the collections as well as a “how to cite” statement, for better citation. Data are converted into standard formats and archived in data warehouses. The CDGP is also a node of the EPOS TCS-AH platform [https://tcs.ah-epos.eu/] and provides Episodes metadata and data.Metadata are open and harvested, they are also pushed on the TCS- AH platform. Data follow FAIR’s statement “as open as possible, as closed as necessary”. CDGP has set an authentication, authorization, and accounting infrastructure (AAAI) to compare distribution rules and user affiliation. Access to data on the TCS-AH platform is conditional on academic membership, and data are provided on-demand. Access controls are made as near the user as possible (subsidiarity principle). Monitoring and reporting are part of the AAAI, and usage is described in terms of use and privacy. Reports are sent to data providers every semester. CDGP operates a regular bibliographic follow-up, e.g. with Google Scholar or by questioning users that downloaded data. On his side, the TCS-AH can only provide general statistics on user engagement, origin, etc.
An introductory review of the integration of local and scientific knowledges in climate services
Authors: Werner Micha , Rastogi Sumiran , van den Homberg Marc , Pechlivanidis Ilias , Pesquer Lluís
Published: February 2023

Climate services have a well-recognised potential for empowering decision makers in taking climate smart decisions; across sectors, public agencies, policy makers, and including citizens. This potential is, however, often not fully realised as the uptake of climate services may be hampered by a range of barriers, including the lack of understanding of the needs of users, and the poor recognition of the knowledge users themselves have. Research shows, however, that the users climate services intend to serve often have a well-developed knowledge of the climate systems around them based on their observation and experience. In a recently initiated H2020 research project, Innovating Climate Services through Integration of local and Scientific Knowledge (I-CISK, https://icisk.eu) we recognise that integrating multiple knowledges through co-creation of climate services with users, can contribute to closing the usability gap, despite the challenges to these knowledges as a result of demographic, climatic and environmental change.
Here we present an introductory review of the current state of the art in the integration of local knowledge in climate services. This review does not aim to comprehensively address the very broad and multiple dimensions of local knowledge, but rather gives a perspective of current approaches in science and practice to the integration of local and scientific knowledge. We first explore what we consider as local knowledge within the scope of this review, which will also be used as a reference to inform our further research on local knowledge within the context of its integration in climate services in the I-CISK project. We then review how local knowledge is used in climate services, and introduce a basic typology of how local knowledge and scientific knowledge are considered and/or integrated within climate services. Finally, we provide a reflection on the challenges and directions of local and scientific knowledge integration in climate services, and give a brief outlook on how these challenges will be addressed in the I-CISK project.
Co-Simulation of Seasonal Aquifer Thermal Energy Storage and District Heating Grid using the Functional Mock-Up Interface
Authors: Ohagen Max , Pham Hung , Bossennec Claire , Sass Ingo
Published: February 2023

District heating grids (DHG) face the problem of seasonal variability and peak demands, e.g., there is a high demand for heat in winter and a low demand in summer. Operators of district heating networks and energy suppliers are therefore seeking solutions to store heat and access it at peak times, thus reducing the use of carbon-emitting heat sources. Aquifers are well suited for heat storage because of high storage capacity relative to the surface occupancy and reasonably high recovery efficiency, if geological suitable. In this study, the potential of Aquifer Thermal Energy Storages (ATES) contribution in decreasing seasonal peak heat loads is investigated by numerical modelling. Each part of the overall system (surface and subsurface) is modelled in their corresponding simulation environment. They are numerically coupled with a novel approach, allowing for highest accuracy in both subsystems. The District Heating Grid is modelled in the object-oriented modelling language Modelica including the Open-Source library MoSDH. Using the Functional Mock-Up Interface (FMI) the Modelica models are exported to executable Functional Mock-Up Units (FMU). The groundwater flow and heat transport processes are modelled in the finite-element software FEFLOW. By developing a C++ Plug-In for FEFLOW the FMU is imported and dynamically co-simulated. This approach allows for easier adjustments in both subsystems and more coupling options to existing models and softwares.  Through numerical analysis different hydrological and geological scenarios of the ATES and different operational cycles are investigated to determine the long-term efficiency and capacity of the storage. This modelling approach can be used to develop strategies for the operation of the ATES as well as to evaluate in advance whether geological conditions are suitable for the particular network situation.
Using InSAR time series to characterize landslide deformation dynamics in the south-central Andes
Authors: M.Aref Mohammad , Bookhagen Bodo , R. Strecker Manfred
Published: February 2023

Slow-moving landslides are an important erosional geomorphic process that shape hillslopes and transport large amounts of sediment material to river channels. They may have potentially catastrophic consequences for infrastructure and human life. Identifying the spatiotemporal pattern of hillslope deformation is essential for understanding the kinematic evolution of hillslope failure and mitigating associated hazards. InSAR (Interferometric Synthetic Aperture Radar) is an effective geodetic method for mapping landslide deformation with high spatiotemporal resolution and precision, especially where direct access to the hillslope areas is difficult.The study area in the south-central Andes is characterized by steep climatic and topographic gradients. The low-elevation eastern foreland areas with dense vegetation cover change to semi-arid and arid, near-vegetation-free high-elevation areas. InSAR phase estimation and landslide mapping in such a complex region can be affected by spatial and temporal variations of soil moisture, vegetation cover, and atmospheric regime.  In this study, we extract InSAR time series from the C-band ascending and descending track of Sentinel-1A/B data acquired between 2014 and 2022 and the L-band ascending track of ALOS1 PALSAR data acquired between 2006 and 2011 in the south-central Andes of northwest Argentina. We compare Sentinel deformation time series and maps derived from the linear small baseline subset technique with different numbers of connections in sequential interferogram formation with non-linear phase inversion techniques. We assess the phase bias contribution of short-temporal baseline interferograms for the time series analysis and propose several correction techniques tailored to this study area. Statistical and weather based models are used to reduce the impact of tropospheric delay on the deformation signal, especially during convective events controlled by the South American Monsoon and the large fluctuation of topographic relief effects on the tropospheric phase delay. We investigate the difference between tropospheric correction methods. We further implement a double-difference filter with different local and regional spatial filters to reduce the tropospheric delay on the InSAR time series. After additional filtering steps to remove further ionospheric noise in the time series, we identify the landslide spatial extent and their dynamic through spatial analyses.  Our results reveal multiple landslides, including three transitional bodies with downslope velocities of 5-10 cm/yr that demonstrate the importance of carefully filtering InSAR time series for slow-moving landslide detection.  
Modelling horizontal propagation of orographic Gravity Waves in climate models
Authors: Rhode Sebastian , Eichinger Roland , Preusse Peter , Garny Hella , Krasauskas Lukas
Published: February 2023

Gravity waves (GWs) transport energy within the atmosphere both in vertical and horizontal direction. While the former is considered in climate models via parameterizations, the latter is often not modeled in most long time simulations. Especially orographic GWs can propagate horizontally more than 1000 km from their sources, however, and thereby de- or accelerate winds in completely different regions. To remedy this, we present a model that is capable of describing orographic GW sources and the associated GWs and their propagation in the atmosphere. From this, we can approximate general propagation pattern, which in the following can be used in climate models (here EMAC) to improve the orographic GW parameterization. The first simulations show strong redistribution of wave drag from land masses and thereby a closing of the gap of missing wave drag at 60°S.
Intra-technique VLBI combination by handling software-specific dependencies
Authors: Hellmers Hendrik , Modiri Sadegh , Thaller Daniela , Bloßfeld Mathis , Seitz Manuela
Published: February 2023

The IVS Combination Centre, operated by the Federal Agency for Cartography and Geodesy (BKG, Germany) in close cooperation with the Deutsches Geodätisches Forschungsinstitut (DGFI-TUM, Germany), generates and releases the combined products of the International VLBI Service for Geodesy and Astrometry (IVS). These session-wise solutions are achieved by an intra-technique combination utilizing the individual contributions delivered by multiple IVS Analysis Centres (AC). For the IVS contribution to the ITRF2020, the re-processed sessions containing 24 h VLBI observations have been submitted by eleven different ACs, where a total number of seven different software packages are utilized. As a result, the session-wise SINEX files are delivered, including datum-free normal equations containing the station coordinates, the source positions and full sets of the Earth Orientation Parameters (EOP). As the same software packages are used by various ACs (e.g. CalcSolve by five ACs), the combined solution is in danger of being dominated by these contributions. The estimates of EOP and station coordinates are affected then mainly by the software specific modelling.This work focuses on an optimal weighting strategy to handle dependencies due to identical software packages in the ACs’ contributions. Thereby, software specific sub-combinations are carried out in the first step to employ the strategy. Finally, the ultimate combination consists of the weighted individual contributions of each applied software. In order to assess the quality of the individual components of the combination - especially in comparison to the contributions of the individual ACs – the internal as well as the external comparisons of the estimated EOP are carried out, where the combined solution together with the external time series (e.g., IERS Bulletin A) serve as a reference.
Effects of bias in an LAI data assimilation system on carbon uptake and hydrological variables and over Europe
Authors: Scherrer Samuel , De Lannoy Gabrielle , Heyvaert Zdenko , Bechtold Michel , Albergel Clement , El Madany Tarek S. , Dorigo Wouter
Published: February 2023

Vegetation is a major control on land-atmosphere fluxes of carbon and water. An improved representation of vegetation in land surface and dynamic vegetation models can therefore improve both short-term weather predictions as well as long-term climate projections. 

State update data assimilation (DA) of remotely sensed leaf area index (LAI) is one way to obtain vegetation state estimates consistent with physical constraints from a land surface model and observational data. Most LAI DA studies so far used bias-blind DA systems, i.e. they did not explicitly take bias between observations and model into account. However, if the observations are biased against the land surface model, this might hamper  the performance of the DA system, because it can induce instabilities in the model. We therefore examined the effect of bias on an LAI DA system, and compared a bias-blind LAI DA system with bias-aware approaches.  

For this purpose, we assimilated the Copernicus Global Land Service (CGLS) LAI into the Noah-MP land surface model over Europe in the 2002-2019 period. 

We find that in areas with large LAI bias, the bias-blind LAI DA by design leads to a reduced bias between observed and modelled LAI and GPP, but it also has strong impacts on soil moisture, leading to a worse agreement with independent, satellite-derived ESA CCI soil moisture. Furthermore, the bias-blind LAI DA produces a pronounced sawtooth pattern due to model drift between update steps. This drift also propagates to short-term estimates of GPP and ET. Furthermore, internal DA diagnostics indicate suboptimal DA system performance. 

The bias-aware approaches avoid the negative effects of the bias-blind assimilation, and still improve anomaly estimates of LAI. Therefore, bias-aware LAI DA might be a useful method to consider in LAI DA, especially when anomalies of LAI or GPP are of interest. 

Our results furthermore show that LAI of CGLS and Noah-MP show strong disagreement especially in dry climates. Model calibration or DA methods that include parameter updating could be an alternative to bias-aware DA to reduce these discrepancies. Our results can guide such efforts, and highlight the need for multiple constraints. 
Neutral Current Sheet Displacement in Reaction to the Radial Interplanetary Magnetic Field at Mercury: Statistical Results from MESSENGER Data.
Authors: Heyner Daniel , Pump Kristin , Hercik David , Exner Willi , Narita Yasuhito , Plaschke Ferdinand , Schmid Daniel , Slavin Jim , Volwerk Martin
Published: February 2023

Mercury possesses a weak planetary dipole moment and is subject to a strong solar wind inflow. Thus, a small magnetosphere is formed. On the nightside, a neutral current sheet elongates the magnetic field lines to form a magnetotail. From hybrid simulations it is known that this current sheet reacts to changes in the interplanetary magnetic field (IMF). In order to understand the magnetospheric reaction to changes in the solar wind, it is essential to further assess the neutral current sheet movements. The strongly radial IMF at Mercury facilitates magnetopause reconnection in high latitudes which decreases the magnetic pressure in one of the magnetospheric lobes depending on the radial IMF polarity. This produces a northward (or southward) shift of the neutral sheet. Here, we present statistical results from in-situ MESSENGER magnetic field data analysis on the IMF direction as well as the neutral sheet displacement. MESSENGER was a single probe in orbit around Mercury and, as such, it was blind to the solar wind state after having entered the bow shock. Thus, we need to estimate the current IMF radial polarity for the time frame with the probe located inside the magnetosphere. For this, we evaluate different interpolation methods with an adapted bootstrap analysis method on data taken within the upstream solar wind at Mercury. Eventually, the outcome of the statistical analysis on the neutral sheet displacement is compared to the results from hybrid simulations done in the past.
GNSS-seismology for anthropogenic earthquakes
Authors: Kudłacik Iwona , Kapłon Jan , Fortunato Marco , Kaźmierski Kamil , Crespi Mattia
Published: February 2023

The high-rate GNSS has been proven to be an effective tool to describe moderate and strong natural earthquakes, whereas the much less addressed application is monitoring anthropogenic earthquakes, such as mining tremors, where the noise and displacements have similar values. Although the anthropogenic events have small magnitudes (usually below 4.5), they also have much shallower epicentres (depths up to 1-2 km). Therefore, the vibrations they cause are often felt and may have a dangerous impact on the ground, structures and infrastructure nearby.Here we show that with the high-rate multi-constellation GNSS observations (GPS+Galileo), we can reliably detect the low-magnitude shallow anthropogenic earthquakes and characterise them in terms of displacements and velocities. Our filtering procedure is based on multiresolution analysis and successfully retrieves the small signal of ground vibrations. We analysed five mining tremors with magnitudes of 3.4-4.0 and presented the results from high-rate GNSS position changes calculated parallel with the PPP and variometric approach. The accuracy was very few millimetres for displacements and 1-2 cm/s for velocities. We obtained satisfying correlations with seismological data in correlation, peak values comparison and earthquake first epoch determination. Finally, considering the high-rate GNSS positioning noise level, we demonstrate the capacity to resolve the dynamic displacements from high-rate GNSS at the epicentral distance of about 7-8 km.
Ionospheric F-Layer Scintillation Variabilities as Observed by COSMIC/FORMOSAT‐3 During Sudden Stratospheric Warming Events
Authors: Ye Hailun , Xue Xianghui , Yu Tao , Yi Wen , Sun Yang-Yi , Dou Xiangkang
Published: February 2023

Sudden stratospheric warming (SSW) events occurred in winter polar stratosphere play a significant effect on the global ionosphere and atmosphere. However, the SSW-induced effects on small-scale structure in the ionosphere are generally lack of understanding. Ionospheric F-layer irregularities is kind of small-scale structure, which can affect the trans-ionospheric radio wave, leading to so-called ionospheric scintillation phenomenon. Thus, the role of SSW on the small-scale structure in the ionosphere can be reflected by studying the characteristics of ionospheric scintillation during SSW events. In the present work, we investigate the variation of the equatorial premidnight F-layer scintillation using COSMIC/FORMOSAT-3 data during SSW events. It found that the occurrence frequency and altitude of ionospheric F-layer scintillation obviously suppressed during SSW events. It suggested that the SSW event has a significant effect on the small-scale structure in the Earth's ionosphere, having potential application for satellite navigation and communication.
BepiColombo: Operations and Data Analysis through the Quick-Look Analysis (QLA) tool
Authors: Cornet Thomas , Macfarlane Alan , Racero Elena , Besse Sebastien , Martinez Santa
Published: February 2023

The ESA-JAXA BepiColombo mission is currently en route to Mercury since October 2018. It consists of the ESA Mercury Planetary Orbiter (MPO) and the JAXA Mercury Magnetospheric Orbiter (MMO) spacecraft which, along with the Mercury Transfer Module (MTM), are stacked all together during the seven years’ cruise phase. This long cruise phase is interspersed by nine planetary flybys used to reach Mercury’s orbit capture. In this configuration, most of the MPO instruments located on the nadir side are obstructed by the MTM and cannot observe. Nevertheless, a subset of “side-looking” instruments can be operated in the stacked-spacecraft configuration during the cruise and gather scientific data. These instruments, mostly dedicated to the study of the Hermean environment (magnetic field, solar wind, exosphere), are operated during the planetary flybys as well as for several cruise science observations. Such events are used to test the BepiColombo Science Ground Segment (SGS) operating systems and processes. The SGS develops the Quick-Look Analysis (QLA) tool that will support the rapid analysis of the instruments’ operational and scientific data acquired during the mission science phase observations, starting in 2026. At present, the tool is used to support cruise and flybys operations, in addition to fostering science collaborations between the BepiColombo instrument teams through its data sharing capabilities. We will present the current status and functionalities.
Subduction, continental collision, and mantle dynamics in the Mediterranean - Tethyan realm: impact on oceanic circulation, climate, and the biosphere
Authors: Straume Eivind , Steinberger Bernhard , Becker Thorsten , Faccenna Claudio
Published: February 2023

Topography generated by subduction, mantle flow, volcanism, and continental collision in the Eastern Mediterranean – Tethyan realm enabled migration and diversification of terrestrial and marine faunas and facilitated Cenozoic (66 – 0 Ma) oceanographic and climatic changes. However, the topographic evolution of key regions and events such as closing the link between the Atlantic and Indo-Pacific Oceans through the Tethys Seaway, and the potential link between the Arctic Ocean and Paratethys Sea through the West Siberian Seaway, are still debated. Here, we review a series of published regional paleogeographic indicators including geological and biogeographic data and generate a new, continuous Cenozoic (i.e.,1 Myr time intervals) digital elevation model for the Tethyan realm. Recent paleoclimate modeling using a state-of-the-art Earth system model (the NorESM-F) show that related, and relatively small changes in paleogeography in these regions can cause large global ocean circulation changes. In particular, shallowing the Tethys Seaway facilitates a stronger overturning circulation in the Atlantic Ocean, while an open West Siberian Seaway may cause freshwater leakage from the Arctic Ocean; this weakens the overturning in the Atlantic Ocean if the Tethys Seaway is open. We further investigate the possible contribution of mantle convection to the evolution of this regional system using new, time-evolving dynamic topography models, and examine the consequences for mammal migration, ocean circulation, and climate. We show that paleotopographic changes in the West Siberian Seaway correlate with changes in dynamic topography. Our findings indicate a link between deep mantle convection, surface evolution, and climatic changes on geological timescales.
Identifying the limits to fire growth in Eastern Siberia
Authors: Janssen Thomas , Veraverbeke Sander
Published: February 2023

Boreal forests store about one third of the world’s forest carbon and may store even more carbon in the future because of the positive effects of rising atmospheric CO2 concentrations on photosynthesis and plant growth. However, fire frequency and severity have also been increasing in boreal forests in the last decades, which might offset their carbon sink potential. In Eastern Siberia, the dry and hot summers of 2020 and 2021 showed exceptionally high fire activity. However, even large fires that can spread for several months, eventually come to an end. This can be because of a change in the weather or because fires run out of fuels. Here, we aim to quantify the controls of fire growth in Eastern Siberia using high resolution landscape variables and hourly ERA-5 meteorological variables. We harmonized the burned area product from the Fire Climate Change Initiative and active fire product from the Visible Infrared Imaging Radiometer Suite, and derived fire perimeters from them for the period between 2012 and 2021. Along these fire perimeters, we then identified spatial changes in landscape variables (i.e. a decline in tree cover or increase in surface water) and temporal changes in hourly vapor pressure deficit and wind. By doing so, we could attribute causes of why fires stopped spreading.
Flowering dynamics of nectar and pollen sources in Hungary based on Sentinel-2 satellite data
Authors: Vincze Csilla , Leelőssy Ádám , Vincze Ferenc , Mészáros Róbert
Published: February 2023

Knowledge of the phenological dynamics of various flowering plants is important for food supply and essential for analysing and modelling adaption of pollinators, especially the honey bees, Apis melifera. The increased frequency of extreme events associated with climate change has resulted in new challenges for farmers as well as beekeepers, and has made research on this issue a priority for adaptation planning. Satellite products can be used for phenological monitoring and detection with good spatial coverage providing valuable information for agriculture and beekeeping. In this study, we investigated the flowering period and dynamics of the two most important honey crops in Hungary, Sunflower (Helianthus annuus L.) and Oil Seed Rape (Brassica napus L.). To generate flowering time series data from Sentinel-2 we used the MSIL2A product in 20-meter resolution, which contains 10 spectral bands with 5 days revisit days. This product also contains additions mapping data helping the classification of the studied area. The research has been created using the Ecosystem Map of Hungary, which also a 20-meter-resolution map helping us to describe the agricultural land developed in 2020. To find the honey producing crops, we used machine learning applications for classification of the arable lands and these desired parcels. Subsequently, flowering timeline was estimated from NDVI and NDYI fields obtained from Sentinel-2 satellite data. Hive weight time series was measured locally with automatic hive scales during the flowering seasons of 2021-2022. The scales grants the apiarists supplementary information like weight in a 10-minute interval. This provide essential information about the health and productivity of the colony and enables information to be gathered before winter season or swarming events. We examined the results of the satellite data against the hive weight data during the honey collecting period and investigated with the actual meteorological conditions to determine a multiplex relationship between the parameters. A method is presented to apply local honey collection data to evaluate and downscale satellite-based phenological estimates for applications in beekeeping.
Effects of forest management on stand structural variability and microclimate in boreal forests
Authors: Aalto Iris , Aalto Juha , Hancock Steven , Valkonen Sauli , Maeda Eduardo
Published: February 2023

In boreal forests, uneven-aged management has recently become an attractive alternative to even-aged rotation forestry. These different management types, based on selection felling and clear-cutting, respectively, can result in substantial differences in the structural characteristics of  forest stands. Therefore, management modifies net surface radiation and heat fluxes and further regulates microclimatic variability important for forest organisms and ecosystem processes. Yet, the magnitude and structural drivers of microclimate variability in managed boreal forests have remained poorly understood. Here, we studied the stand structure and microclimate of 20 study plots including even-aged and uneven-aged forest stands in the Vesijako Research Forest in southern Finland. We used terrestrial laser scanning (TLS) to quantify the structural characteristics of the sites and measured soil and air temperature with 80 microclimate loggers in 2021–2022. The TLS data showed that the total amount of plant material did not differ between the management types. However, there were significant structural differences in vertical layering and horizontal heterogeneity of vegetation. Our preliminary results show significant differences in microclimate temperatures depending on stand age category. These differences were clearest at the hottest and coldest times of the year. Air and soil temperature variability in uneven-aged stands resembled at stand level the variability that is encountered in even-aged management only across larger areas including young, immature and mature stands. Uneven-aged stands may therefore support more diverse habitats than even-aged forests. We show that the total amount of plant material was a stronger structural modifier of air temperatures than the vertical arrangement of vegetation. We expect our results to clarify how forest management contributes to shaping microclimates experienced by organisms, which has potential consequences on biodiversity and ecosystem resiliency.  
Scientific drilling in Northeast Greenland: Greenland Ice Sheet sensitivity to polar amplification and long-term ice-ocean-tectonic interactions
Authors: Pérez Lara F. , Knutz Paul C. , Hopper John , Seidenkrantz Marit-Solveig , O'Regan Matt
Published: February 2023

The projections of future scenarios under the current trend of global climate change demand a better understanding of the long-term ice-ocean-tectonic interactions, and in particular the potential meltwater contributions from modern ice sheets. The sensitivity of the Greenland Ice Sheet to polar amplification, changes in ocean heat transport and deteriorating perennial sea ice conditions makes the Northeast Greenland margin one of the most critical locations to understand the impact of future climate change on ice sheet instability and associated sea level rise. The development of oceanic gateways controlling the long-term water mass exchanges between the Arctic and Atlantic oceans, notably the Fram Strait and the Greenland-Scotland Ridge, have played a pivotal role for the Cenozoic evolution of the Northeast Greenland regions. In Northeast Greenland, ice-ocean-tectonic interactions and coupling between the ice sheet, ocean and sea ice are readily observable today, but geological records that can illuminate long-term trends are lacking. Consequently, NorthGreen MagellanPlus workshop was organised at the Geological Survey of Denmark and Greenland in collaboration with Aarhus (Denmark) and Stockholm (Sweden) universities in November 2022 as an international effort to develop Mission Specific Platform (MSP) proposals on Northeast Greenland margins under the umbrella of the European Consortium for Ocean Research Drilling (ECORD). For three days, seventy-one participants (56 in person + 15 online) discussed the key scientific questions and primary targets for scientific drilling in Northeast Greenland. Three pre-proposals have been initiated during the workshop targeting Morris Jesup Rise, Northeast Greenland continental shelf and Denmark Straight.
Contrasting the internal and external components of Atlantic Multidecadal Variability in CMIP6 historical simulations
Authors: Robson Jon
Published: February 2023

Over the observed period, North Atlantic Sea surface temperatures have gone through cycles of anomalous warming and cooling relative the global mean. This variability has become known as the Atlantic Multidecadal Variability (AMV), and it has been associated with important regional climate impacts. However, in recent years there has been considerable controversy over the origins of AMV. In particular, there is debate over whether AMV is a natural phenomenon (e.g., an expression of internal variability or natural external forcings), or whether it was caused by human activity through the impact of anthropogenic aerosol forcing.Here, an analysis of CMIP6 multi-model historical simulations is presented which isolates the internal and externally forced AMV. The analysis shows that, although there is substantial externally forced AMV in the CMIP6 historical simulations, the forced variability is part of a wider hemispheric signal and is not specific to the North Atlantic like in observations. Therefore, the magnitude of the externally forced variability is highly dependent on the definition of the AMV index used. Ocean circulation changes consistently lead the internal AMV across models, but there is no-clear relationship for the external AMV. AMV is also associated with broader changes than just sea surface temperatures, but this multivariate fingerprint of AMV is significantly different between the internal and external components. For example, internal AMV is associated with salinity anomalies and increased turbulent heat loss across the subpolar North Atlantic that agree broadly with observations. However, in contrast, the externally forced AMV is associated with freshening and reduced heat loss across the subpolar North Atlantic and especially in models with the strongest aerosol forcing. Overall, the analysis suggests that internal variability remains a likely hypothesis to explain AMV, but questions remain on whether models adequately simulate the forced response.
Can Smartphone Raw GNSS Measurements Contribute to Ionospheric Modelling?
Authors: Farzaneh Saeed , Forootan Ehsan
Published: February 2023

The upper part of the Earth’s atmosphere is important for the ground-based and satellite radio communications and navigation. It consists of free electrons and ions, mainly ionized by solar radiation. The free electrons in the ionosphere strongly impact the propagation of radio waves. Therefore, modelling and predicting ionosphere are important for many space weather and geodetic applications. In this study, we apply geometry-free multi-GNSS approach enabling the simultaneous retrieval of vertical total electron content (VTEC). Unlike previous studies, multiple frequency GNSS receivers of smartphones and more accurate geodetic receivers are used to understand how various code/phase observations could be combined. The smartphone observations are typically less precise and affected by multipath and they contain frequent cycle slips. Various combinations of the ionospheric observations, using both code and phase measurements, are tested to understand how to mitigate the challenges and to account for the measurements’ quality. Finally, the advantages and disadvantages of these combinations are explained.

Keywords: Smartphone, Vertical Total Electron Content, Multi-frequency GNSS
GPU-based numerical models of rapid ductile strain localization due to thermal runaway
Authors: Spang Arne , Thielmann Marcel , Kiss Daniel
Published: February 2023

Strain localization is a crucial process for lithosphere and mantle deformation as it allows for the formation of faults and shear zones that enable plate tectonics. In the crust, strain localization usually occurs via brittle failure (i.e., breaking the rock). The deeper and/or hotter the setting, the less likely brittle failure becomes as the critical stress increases with the increasing overburden pressure while the temperature-dependent rheology of rocks limits the stresses that can be accumulated before being relaxed by slow, viscous flow.Yet, we do observe fast and localized deformation (i.e., earthquakes) at depths of several hundred kilometers. These deep earthquakes either require local differential stresses of several Gigapascal (GPa) to trigger brittle failure or a different, ductile failure mechanism that significantly reduces rock strength while at the same time creating highly localized shear zones. Here, we investigate the feedback loop of visco-elastic deformation and shear heating to determine whether their combination can lead to a localized viscosity reduction and allow for fast slip.Modeling this feedback loop and the accompanying strong localization of deformation poses a challenge for continuum modeling approaches, in particular when highly nonlinear rheologies such as dislocation creep and low-temperature plasticity are employed. Here, we present a collection of 1D and 2D numerical codes written in the Julia language which use the pseudo-transient approach and graphical processing unit (GPU) computing to model the process of ductile localization and thermal runaway in a simple-shear setting. Our models employ a nonlinear, visco-elastic rheology, including grain-size-dependent diffusion creep, stress-dependent dislocation creep and low-temperature plasticity. We find that the combination of the aforementioned mechanisms is sufficient for deformation to localize on a small perturbation and then propagate through the model similar to a brittle rupture. Our models show that low-temperature plasticity acts as a stress-limiting mechanism that facilitates numerical stability during thermal runaway. In a systematic series of models, we investigate under which conditions thermal runaway occurs and which role each of the rheological components plays in the localization process.
Chaos in flatland: mixing in unsteady two dimensional porous media flow
Authors: Pierce Kevin , Linga Gaute , Moura Marcel
Published: February 2023

Solute mixing is efficient in a steady three dimensional porous media flow, since filaments of solute elongate exponentially fast in time. This "chaotic" elongation enables molecular diffusion to rapidly distribute solute concentrations. In two dimensional steady flows, such as through thin fractures in rock, existing knowledge indicates that filaments of solute elongate much more slowly than exponentially, meaning the mixing is far less efficient. Here, we present experimental evidence that when porous media flows are instead unsteady, two dimensional mixing becomes chaotic.  Using 3D printed model porous media with steady longitudinal and oscillating transverse flow components, we measure Lyapunov exponents of filament elongation and quantify solute stretching and folding statistics as a function of the frequency and amplitude of the transverse flow. We find resonances in mixing frequency which are consistent with numerical simulations of the model geometry. These findings improve our understanding of mixing in geological systems and provide insights which may be useful to design efficient geologically-inspired mixing devices in the future.
Integrated Seismic Program (ISP): A New Python GUI‐Based Software for Earthquake Seismology and Seismic Signal Processing
Authors: Cabieces Roberto , Olivar-Castaño Andres , C. Junqueira Thiago , Relinque Jesús , Vackár Jiří , Palacios Cristina , Harris Katrina
Published: February 2023

Integrated Seismic Program (ISP) is a graphical user interface designed to facilitate and provide a user‐friendly framework for performing diverse common and advanced tasks in seismological research. ISP is composed of six main modules for earthquake location, time–frequency analysis and advanced signal processing, implementation of array techniques, seismic moment tensor inversion, receiver function computation and and a new module for ambient noise tomography.Recently the Ambient Noise Tomography module has been upgraded with a tool specifically designed to synchronize Ocean Bottom Seismometers (OBSs) and to denoise the OBSs seismogram of the vertical component from tilt and compliance noise. The new tool has extensively been tested with data from UPFLOW project (https://upflow-eu.github.io).In addition, several support tools are available, allowing the user to create an event database, download data from International Federation of Digital Seismograph Networks services, inspect the background noise, and compute synthetic seismograms.ISP is written in Python3, supported by several open‐source and/or publicly available tools. Its modular design allows for new features to be added in a collaborative development environment.
Seoul carbon emissions estimated with Bayesian inverse modeling of measurements from ground and space
Authors: Sim Sojung , Jeong Sujong
Published: February 2023

The bottom-up method of estimating carbon emissions from fossil fuel use based on socio-economic databases has significant uncertainty. In particular, this uncertainty increases when the spatial and temporal scales are fine, such as in cities. Therefore, an independent and complementary top-down method has been used to verify carbon emissions estimated by the bottom-up method. This method uses the atmospheric CO2 measurement, transport model, and the inverse model. In this study, carbon emissions provided by ODIAC were improved using ground and satellite CO2 observation data measured in 2019 for Seoul. We used atmospheric CO2 concentration from four observation sites located in Seoul and the column-averaged dry air mole fractions of CO2 from OCO-2. In order to quantify the footprint, which is the flux sensitivities on observation sites, STILT and X-STILT model was used for the ground observation and satellite observation, respectively. The result showed that prior carbon emissions in specific areas including power plants and airport were underestimated. The carbon emission uncertainty decreased through Bayesian inverse model, and it was found that the calculated observation and emission error covariance were appropriate through the reduced chi-square calculation. We assessed Bayesian inverse modelling of Seoul carbon emission from fossil fuel use using measurement from ground and space, which will enable effective carbon neutrality policy decisions for Seoul.This work was supported by Korea Environment Industry &Technology Institute (KEITI) through "Climate Change R&D Project for New Climate Regime", funded by Korea Ministry of Environment (MOE) (2022003560006)
Increasing heat stress under different levels of global warming with WRF regional climate simulations for the MENA-CORDEX domain.
Authors: Ntoumos Athanasios , Hadjinicolaou Panos , Zittis George , Vautard Robert , Lelieveld Jos
Published: February 2023

Heat extremes are expected to augment in frequency and magnitude due to global warming, with the Middle-East – North Africa (MENA) region emerging as a prominent climate change hotspot. In this study, we assess the future extreme heat conditions in the MENA region under various levels of global warming. For this, WRF high-resolution regional climate simulations (at 24 km grid size) are carried out for the MENA-CORDEX domain for different 20-year periods corresponding to the current climate and three global warming levels (+2°C, +3°C and +4°C relative to the pre-industrial period). The future changes for the annual warmest day (TXx) and night (TNx) are presented as well as the projected levels of humid heat through the analysis of the Heat Index (HI) and wet-bulb temperature (TW). Results generally indicate more intense warming over the northern part of the Mediterranean basin. For strong warming (+4°C), the indices of Warmest Day (TXx) and Warmest Night (TNx) are projected to increase by more than 6°C in the northern part of the domain. At 2°C of warming, areas around the Gulf are expected to experience extremely dangerous levels of humid heat, with Heat Index (HI) > 51° C, and Wet Bulb Temperature (TW) > 30° C. If global warming exceeds 2°C, the frequency and extent of heat extremes in the region will greatly increase, with some areas of the domain reaching the TW survivability limit of 35°C. Our research also suggests that heat events that currently occur once every 50 years may occur every few years at a global warming level of 2°C. At even higher warming, extremely dry and humid heat events are expected to occur multiple times per year.