bluuebunny/crossref_metadata_2025 huggingface dataset:
Mid-Pliocene subtropical front variability in the Southern Ocean
Authors: Hou Suning , Stockhausen Malte , Toebrock Leonie , Sangiorgi Francesca , Starr Aidan , Berke Melissa , Ziegler Martin , Bijl Peter
Published: February 2023

The mid-Pliocene (3.3-3.0 Ma) is a time when the Earth's climate fluctuated between cold glacial conditions (marine isotope stage M2; 3.3 Ma) and periods when global temperatures were ~3°C warmer than the pre-industrial (Mid-Pliocene warm period; 3.3-3.025 Ma) when CO2 concentrations reached ~400 ppm. Thus, the paleoclimate reconstruction of this time interval provides an analogue of the present-day and near-future climate change in a moderate pCO2 increase scenario. Although fluctuations in benthic δ18O in the mid-Pliocene were predominantly associated with Northern Hemisphere glacial dynamics, the contribution of Antarctic ice to mid-Pliocene glacial-interglacial cyclicity is unknown. Moreover, the surface oceanographic response of the Southern Ocean to Pliocene glacial-interglacial climate change is poorly documentedWe studied 2 sedimentary records from offshore west Tasmania (ODP Site 1168) and the Agulhas Plateau (IODP Site U1475), both located close to the modern position of the subtropical front (STF) in the Southern Ocean and encompassing the mid-Pliocene. The STF is a crucial surface water mass boundary separating cold, fresher subantarctic waters and warm, more saline subtropical waters and plays a key role in global ocean circulation, ocean-atmosphere CO2 exchange and meridional heat transport.We use lipid biomarkers, dinoflagellate cyst assemblages and benthic foraminiferal clumped isotopes to reconstruct surface and bottom oceanographic conditions over the mid-Pliocene including the M2 glaciation. We identify similar sea surface temperature (SST) changes at the two sites. Site 1168 SST cools from 18°C to 12°C and at Site U1475 from 21°C to 18°C across the M2 glaciation. Dinoflagellate cyst assemblages suggest strong latitudinal shifts of the subtropical front associated to Pliocene glacial-interglacial climate changes. However, the most profound assemblage shift occurs at the M2 deglaciation stage at both sites, suggesting strong and unprecedented surface water freshening. Preliminary clumped isotope results suggest bottom water temperatures at Site 1168 are stable around 9°C between M2 and mid-Piacenzian warm period, indicating that the enrichment in δ18O across the M2 is mainly contributed by large ice volume changes. We interpret the surface water freshening of the subantarctic zone as signaling major iceberg calving following the M2 glaciation, suggesting that the Antarctic contribution to the M2 glaciation was profound.
Geographical heritage in natural protected areas of Tenerife (Canary Islands, Spain)
Authors: García-Hernández Rubén , Dóniz-Páez Javier , Beltrán-Yanes Esther , Pérez Nemesio M. , Hernández Pedro A.
Published: February 2023

Tenerife is the largest (2034 km2), and the highest (3718 m a.s.l.) island of the Canary. It has been built up as a result of the accumulation of different volcanic materials during the last 12 million years. In Tenerife it can be recognized different morphostructures: three shield volcanoes (Anaga, Teno and Adeje), two volcanic ridges (Pedro Gil and Abeque), a important volcanic field in the south of the island, a central caldera (Las Cañadas), a complex stratovolcano (Teide-Pico Viejo) and hundreds of cinder or scoria monogentic cones scattered throughout the island's geography. Despite this geological and volcanic richness, geological heritage is currently given less importance than biogegraphical heritage when identifying, defining and catalogue natural areas to protect (NPA). The objective of this work is to obtain the classification of geomorphological heritage of the total NPAs of the island and show the importance that these volcanic forms and their processes have in the natural landscapes of Tenerife. In this work we utilized the methodology elaborated by Serrano and González (2014) and involves a three-way comparison of the different values of the geomorphosites: scientific, cultural and use and management values. The values of geomorphological heritage are expressed from 1 to 5. Tenerife has forty-three NPAs with a total of more than 110,098 hectares, which represents more than 49% of its surface. The variety of NPAs are: one National Park, ten Natural Reserves, one Natural Park, two Rural Park, fourteen Natural Monuments, nine Protected Landscapes and six Sites of scientific interest. In general, the NPAs shows the geodiversity of Tenerife´s volcanism with average scientific (1.5), cultural (1.8) and use (2.6) values. These data show the importance of geoheritage in the NPAs of Tenerife (shield volcanoes, stratovolcanoes, volcanic ridges, scoria cones, lava fields, hornitos, lava tubes, lava deltas, calderas, ravines, cliffs, beaches, dunes, etc.), but we can´t avoid the human intervention on several characteristics at these areas with cultural values over than scientific (mythos, legends, archaeological sites, traditional construction, crops, livestock, etc.). The geomorphological heritage analysis expressed the relationship between of the volcanic natural heritage and the humans. (Volturmac-MAC2/4.6c/298).
How important is the change-of-support problem when digital soil mapping involves multi-source spatial data fusion? A real-world application of multivariate geostatistics to the regional scale of Campania (Italy).
Authors: Romano Nunzio , Castrignanò Annamaria , Allocca Carolina , Nasta Paolo
Published: February 2023

Effective techniques for spatial data analysis are required to address the growing need to develop and improve management plans at regional or continental scales. The main purpose of this research is to evaluate the impact of change of spatial support on digital soil mapping. The study is based on the availability of more than 3,300 soil samples collected from the uppermost horizons of farmlands in Campania, an administrative region of southern Italy of about 13,700 km2. Each soil sample was subjected to laboratory tests to determine the following point-referenced primary soil properties: sand and clay contents, oven-dry soil bulk density, soil organic matter, pH, calcium carbonate, and rock fragments. These seven soil properties were mapped over the entire region by using as covariates the following terrain attributes, obtained from the digital terrain model (DTM; 75 m/pixel): elevation, slope, plan curvature, profile curvature, and flow accumulation. Two composite indicators of soil quality were then determined: 1) the soil organic carbon stock (SOCS) in Campania, and 2) the recharge transit time in the alluvial plain of the Sele River where information about the mean annual depth to groundwater is available.In this study, it was crucial to evaluate the epistemic uncertainty associated with the change of support when fusing the point-referenced soil measurements with the block-based terrain attributes. A key issue of our analysis is the modification of the anamorphosis model based on a block rather than a point. Accordingly, our results show how the estimates change when a properly-corrected block Gaussian anamorphosis model is employed instead of the point Gaussian one.By way of conclusion, when the main interest of an investigation is to obtain a map of average soil attributes, the change of support might have little influence on the final estimates, especially when working with nearly symmetrical distributions of soil properties. On the other hand, if one should infer the uncertainty of a variable, as in soil vulnerability mapping, then the change of support matters and is an issue to be adequately accounted for in the spatial analysis of environmental data.
Electron diffusion region embedded in a dipolarization front – an MMS/Cluster conjunction event
Authors: Hosner Martin , Nakamura Rumi , Schmid Daniel , Nakamura Takuma , Panov Evgeny V. , Volwerk Martin , Vörös Zoltan , Roberts Owen W. , Blasl Kevin A. , Settino Adriana , Korovinskiy Daniil , Marshall Andrew T. , Denton Richard E. ,   MMS and Cluster Team
Published: February 2023

Magnetic reconnection, a key energy conversion process in the Earth’s magnetosphere, has extensively been studied during the last few decades. Multi-point missions such as Cluster or Magnetospheric Multiscale (MMS) showed that magnetic reconnection takes place not only at large-scale stable magnetopause or magnetotail current sheets but also in transient localized current sheets.Here, we revisit the Dipolarization Front (DF) event, observed by the MMS spacecraft on September 08, 2018/14:51:30 UT in the Earth’s magnetotail. Previous studies reported that this DF shows a strong non-ExB type electron flow and a crescent-shaped distribution function, suggesting that this DF hosts an electron diffusion region (Marshall et al. JGR, 2020).To further characterize this special event, we (1) use conjunction observations of the MMS and Cluster spacecraft to investigate the event in the context of large scales and (2) apply the polynomial magnetic field reconstruction technique by Denton et al. (JGR, 2020) to characterize the embedded electron current sheet including its velocity and the X-line exhaust opening angle. 
Drainage divide asymmetry as an indicator of large-scale landscape transience on the Southeast Tibetan Plateau
Authors: Gelwick Katrina D. , Willett Sean D. , Wang Yanyan
Published: February 2023

Landscapes are sculpted by a complex response of surface processes to external forcings, such as climate and tectonics. Several major stream captures have been documented on the Southeast Tibetan Plateau, leading to the hypothesis that the region experiences exceptionally high rates of drainage reorganization driven by horizontal shortening and propagating uplift. Here we determine the prevalence, intensity, and spatial patterns of ongoing drainage reorganization on the Southeast Tibetan Plateau and evaluate the relative time scales of this transience by comparing drainage divide asymmetry for four geomorphic metrics that operate at different spatial and temporal scales. Specifically, we evaluate drainage divide asymmetry in catchment-restricted topographic relief, hillslope gradient, normalized channel steepness (ksn), and χ. ksn and χ are both precipitation-corrected to account for the strong precipitation gradient across the region. We calculate the migration direction and Scherler & Schwanghart (2020)’s divide asymmetry index (DAI) in each metric for drainage divides across the entire region in order to analyze how well the asymmetry in these metrics agree along divides and where consistent divide movement is inferred. We find a high incidence of strongly asymmetric divides in all metrics across the entire Southeast Tibetan Plateau. While the magnitude of asymmetry varies significantly between metrics, a majority of divides agree on divide migration direction across all metrics. Divides with higher magnitudes of asymmetry are more likely to agree on migration direction across multiple metrics. While χ agrees least often with the other metrics on migration direction, it agrees on direction >90% of the time when low DAI divides are excluded. We also establish that disagreement in predicted divide migration directions between χ and the other geomorphic metrics can be interpreted as evidence of localized variations in tectonic uplift or erodibility, glacial alteration, or recent lateral stream capture. Our work confirms the high incidence of drainage reorganization across the Southeast Tibetan Plateau and highlights both transient and stable areas in the landscape with unprecedented resolution. In addition, we propose how to combine geomorphic metrics to ascertain how drainage divides migrate across different timescales and identify local deviations in tectonic uplift and erodibility.
Evident decrease in future European soil moisture in the Kiel Climate Model
Authors: St-Pierre Médéric , Latif Mojib , Kjellsson Joakim , Park Wonsun , Borchert Leonard
Published: February 2023

During the last few decades, the European climate has changed significantly. Extreme temperatures are now more frequent than ever since the start of industrialization and changes in the water cycle evident. The soil water content could be affected by these changes disturbing the daily life of many people. More often than we would like, anthropogenic factors and more specifically the CO2 emissions are found to be the causes of these perturbations. In this study, we look into the European soil moisture trends in a changing climate. To achieve this, we use a single grand ensemble of 100 members performed with the Kiel Climate Model (KCM). Each simulation starts with different initial conditions taken from a pre-industrial control run and is forced by a 1%-CO2 increase per year. This means that the atmospheric CO2-concentration doubles after 70 years and quadruples after 140 years. Strong drying over most of Europe is simulated with more than 95% of the ensemble members agreeing on the sign of the change. Central Europe experiences a particularly large drying during spring and summer, while the Mediterranean region is affected all year long by drying. The northern European soil moisture also decreases, but to a lesser extent. The changes over all of Europe are mainly due to a reduction in precipitation and, to a certain degree, an increase in evaporation. Precipitation trends in the KCM ensemble are in good agreement with that in the CMIP6 models forced by the shared socioeconomic pathway 5-8.5 (SSP585).
Magnesium isotope signature of Middle Ordovician dolomites from the Ordos Basin, China
Authors: Li Yining , Liu Wenhui , Shalev Netta
Published: February 2023

As a significant sink of seawater magnesium, δ26Mg values of syndepositional marine dolomites can be utilized to reconstruct seawater Mg isotope composition in the past. This, in turn, may serve as a good tracer for the Mg cycle throughout Earth’s history. Furthermore, δ26Mg values of ancient dolomites precipitated in different depositional environments may help in reconstructing the paleo-conditions that prevailed in these environments, in particular, the hydrology and restriction conditions of ancient sedimentary basins.In this study, we collected Middle Ordovician marine dolomite samples from five profiles distributed in the different locations of the Ordos Basin, North China Plate. During the Ordovician, marine carbonates were deposited in the whole area of the Ordos Basin under different sedimentary settings that can be generally divided into open marine settings, a dolomite platform, and a saline gypsum lake. After systematic petrology observation (optic and cathode luminescence microscope), we microdrilled fine-crystallized dolomite to conduct chemistry and Mg isotope analyses. The dolomites from profile #1, which were deposited in an open marine environment, exhibit the lowest δ26Mg values between -2.31‰ to -2.21‰. The δ26Mg values of dolomite samples are generally heavier toward the more evaporitic center of the basin. The highest δ26Mg values (-1.84‰ to -1.70‰) were measured in samples from profile #5 located in the saline gypsum lake area.We suggest that this gradient of δ26Mg values from the outer parts of the basin toward the center is resulting from a prior formation of dolomite in open versus gradually more restricted settings. Dolomite is enriched in the lighter isotope, 24Mg, relative to its precipitating solution. Thus, under restricted settings, dolomite formation will increase the δ26Mg value of the remaining dissolved Mg in the solution and consequently, also the δ26Mg values of further precipitating dolomites. This further suggests that the Mg isotope composition of dolomite can be used to reconstruct the enclosure degree of ancient evaporitic basins. Together with the observation that δ26Mg values of dolomite samples from profile #1 vary in a narrow range of 0.10‰ between different formations, this also suggests that profile #1 located in open marine settings can be utilized to reconstruct the Mg isotope signature of seawater during the Middle Ordovician.
Spatial pattern oriented optimization of regional scale hydrological models
Authors: Stisen Simon , Cüneyd Demirel Mehmet , Soltani Mohsen , Koch Julian
Published: February 2023

Regional scale hydrological models are often constrained by a group of observation stations, typically for discharge, which each represent a lumped catchment response. While multi-station calibration greatly improves model fidelity, other sources of data and different calibration objectives are often required to improve models for other variables and increase robustness for ungauged areas. Satellite data has often been utilized as an additional source of information for multi-objective optimization. However, in many cases satellite-based data for other variables, such as soil moisture, AET, snow cover, storage change etc. has been applied as timeseries of catchment averages, thereby underutilizing the unique spatial pattern information they carry.In a series of studies a simple alternative approach has been developed to capitalize on the benefits of combining spatial pattern information from satellite data with classical discharge and groundwater head observations for model optimization. By limiting the constraint by the satellite data to pattern information only a very limited tradeoff with other observations is achieved. Meanwhile, the approach ensures realistic spatial patterns of parameter fields and simulations leading to improved transferability to ungauged basins.In light of equifinality, which is often encountered for regional scale models constrained by multiple discharge stations, the approach can as such also be seen as an efficient way of identifying spatially consistent and realistic solutions among a large sample of plausible parameter sets.Here we present two cases, one across six central-European basins using a mesoscale hydrological model (mHM) and another using a national scale groundwater-surface model (MIKE-SHE).
Spatialization and analysis of the GNSS-R measurements around of the Cordouan lighthouse
Authors: Gravalon Théo , Seoane Lucia , Ramillien Guillaume , Darrozes José
Published: February 2023

As the Cordouan lighthouse [N45°35'11"; W1°10'24"] is constructed in the Bay of Biscay, GNSS reflectometry-monitored time series of sea level are characterized by important tidal variations for this site. However, these GNSS-R measurements are impacted by submerged sandy banks that appear at low tide and spoil the estimates of pure sea level. We propose the spatialization of the GNSS reflection points to identify the areas with sandy or rocky parts around the lighthouse. For this purpose, the surrounding of the receiving antenna is divided into juxtaposed geographical cells forming a map filled by water heights estimates according to the position of the reflection points. Water heights are determined using the method of periodogram of 1-second Signal-to-Noise-Ratio (SNR) data on a sliding elevation window of several degrees. In particular, correction of the atmospheric delay effects enables to reduce the dispersion of the water heights versus low elevations by a factor around 2. High variability (more than one meter) and higher means of water heights estimated over months in the eastern part are very consistent with the presence of the shoals, while long-term means and dispersions in cells of plain ocean are much smaller. These results are highly emphasized by the distinction between low and high tides.
Developing techniques and reference materials for LA-ICP-MS U-Pb geochronology of Sn-W minerals
Authors: Szymanowski Dawid , Tavazzani Lorenzo , Buret Yannick , Guillong Marcel , Cortes Calderon Alejandro , Chelle-Michou Cyril
Published: February 2023

Tin-tungsten magmatic-hydrothermal deposits are sources of critical raw materials (Sn, W, Nb, Ta, Li), key to the development of technologies involved in the green transition. However, the current and projected supply of many of these mineral commodities is often dominated by entities whose practices or geopolitical setting may raise issues from a social, political, or environmental standpoint. To meet a steadily increasing demand, new responsible mineral extraction projects must therefore be developed. Successful exploration and economic appraisal of newly identified mineral deposits require (1) an understanding of the ore-forming processes to build an exploration model, and (2) an early estimate of the deposit size to facilitate well-targeted investments. One key parameter that helps to achieve both goals is the knowledge of absolute timing and duration of the mineralisation process.We present new analytical developments in U-Pb dating of strategic Sn-W ore minerals (cassiterite, wolframite, scheelite) using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). We used a suite of Sn-W mineral specimens to characterise U/Pb downhole fractionation behaviour and polyatomic interference patterns for these three matrices, allowing the optimisation of ablation and ICP-MS settings. In parallel with technical developments, we compiled a large library of potential primary and secondary cassiterite, wolframite, and scheelite reference materials (RMs) which we characterised for major and trace elements. To further our understanding of geochemistry of Sn-W phases, we also performed high-resolution compositional mapping of key trace elements (e.g. U, Pb, REE) with an ultra-fast washout laser ablation system.Promising RM candidates will be developed into primary RMs with a careful characterisation of compositional homogeneity and precise age determination by isotope dilution-thermal ionisation mass spectrometry (ID-TIMS). Thus characterised RMs and a set of analytical best practices will be made available to laboratories wishing to test and further develop such methods. The ultimate goal of this effort is to build a set of community shared materials and techniques that will allow precise and accurate temporal characterisation of Sn-W mineralisation.
Impact of a high-energy storm event (Storm Barra) on a multiple intertidal barred system.
Authors: Biausque Melanie , Grottoli Edoardo , Jackson Derek W. T. , Cooper J. Andrew G. , Guisado-Pintado Emilia
Published: February 2023

Multiple intertidal barred systems (MITB) are complex coastal features observed under specific conditions including low to moderate energy waves and macrotidal forcing. Although primarily tide-dominated, MITBs can undergo significant morphological changes under storms and extreme events. In December 2021, storm Barra crossed the U.K. and was the 2nd most energetic event in the past 25 years, to occur on Northern Ireland’s east coast. At the MITB site in Dundrum Bay, offshore waves reached a maximum significant wave height of 5.5 m on December 7th, 2021 and were associated with a peak period and wave direction of 10s and 179°N-oriented respectively. Pre- and post-Barra intertidal DGPS surveys were conducted at Dundrum Bay on the 6th and 9th of December to identify beach morphological changes on MITBs. Despite direct onshore waves reaching the bay, a strong alongshore variability was recorded in the response to Murlough and Ballykinler beaches to Storm Barra. Indeed, according to preliminary results, the western end of the bay shows an elevation of the beach profile, the central area presents onshore migrations of the bars to no significant changes, while the eastern side of the bay (Ballykinler) displays bar crests flattening and linear post-storm profiles.Although storm Barra was the most energetic event recorded during the winter 2021/2022, smaller storm events had modified the morphology of Murlough and Ballykinler beaches throughout the preceding season, leading to some already low pre-Barra beach profiles. Secondly, at the peak of Barra’s energy, the waves were southeast oriented. But the direction of the waves rapidly shifted from onshore to offshore, possibly modifying the impact of Barra on the system. Finally, the shape of the bay, the location of the different profiles and the complex nearshore bathymetry and local geology must have also played a key role dictating the alongshore pattern shown. Previous studies of Dundrum Bay have shown that physical processes driven by waves/tide and geomorphology interactions can undergo significant local modification, leading to a strong alongshore variability in the profiles’ response to seasonal events. Nearshore SWAN simulations will help highlight the role of nearshore hydrodynamics including wave dissipation and re-orientation, wave-driven sediment transport and the impact of storm surge on MITB during an extreme event.
An empirical rainfall threshold approach for the regional civil protection flood warning system: the case study of the Milan urban area
Authors: Gambini Enrico , Ceppi Alessandro , Ravazzani Giovanni , Mancini Marco , Valsecchi Ismaele , Cucchi Alessandro , Negretti Alberto , Tolone Immacolata
Published: February 2023

In recent years the interest towards flood forecasting in urban areas has increased significantly: urban areas and the people living in there are generally very exposed to floods; also, this problem may worsen in the future due to climate and land-use change.Empirical rainfall thresholds could represent a useful tool especially for those river basins where applying hydrological models is difficult. Such an approach can potentially be used for every river cross section whenever enough rainfall-discharge data are collected.In this study, we developed some empirical rainfall threshold with the aim of validating and enhancing the Regional Civil Protection warning system operating in the Lombardy Region.Rainfall data were collected from a total of 92 stations taken from the official regional Environmental Protection Agency of the Lombardy Region (ARPA-Lombardia) and from the network of a citizens science association “Meteonetwork”. Data on hydrometric levels and discharge were obtained entirely through the regional Environmental Protection Agency of the Lombardy Region.The study focused on the small and well urbanized river basins which drain their water towards the city of Milan (mainly Seveso, Olona and Lambro River basins). Simple rainfall-runoff methods and decision theory, as indicated on the local civil protection directory, were used to validate the results obtained.Preliminary results given by this methodology have shown that it could be a helpful tool for local civil protection authorities to take preventive actions for the population, as well as to validate the existing warning systems based on rainfall thresholds.
Social media, vulnerability, and risk perception: three main points for geological disaster management
Authors: Nardini Olga , Morelli Stefano , Pazzi Veronica , Bonati Sara
Published: February 2023

Social media have the potential to significantly influence the disaster risk understanding of natural events of climatic and geological origin, e.g., earthquakes, volcanic eruptions and landslides. Given their considerable diffusion, nowadays they represent a valid support during emergency management processes thanks to their multiple uses in all the different phases of the disaster cycle. The presented results have been achieved carrying out a literature review in the framework of the European H2020 project LINKS ('Strengthening links between technologies and society for European disaster resilience') which aims to strengthen the link between technology and society to improve resilience in four European countries associated with five different risk scenarios. The aim of this research was to investigate how social media influence and impact vulnerability and risk perception and how the increased use of social media as a communication tool during a disaster is shaped by the way the two concepts interact and are conceptualised. The main results are that through social media, it is possible to raise people's awareness of the disaster, also by working on each individual's trust in those who provide information, but also to disseminate useful information and alerts to the population to keep abreast of real-time events, to connect citizens with each other in order to reduce distances and provide psychological support, and to create a social network for those in need. Additionally, social media can be used to manage an emergency and coordinate volunteer actions. The concepts of vulnerability and risk perception are extremely important to be considered when talking about geological hazards and disasters. They are two interconnected concepts that need to be pursued hand in hand in emergency management. The main challenges and factors impacting the use of social media concern access, quality and reliability of information, trust, and awareness of the news being provided, but also personal experience and geographical, social and demographic factors that may influence the way information is perceived and understood. The perception of geological risks directly influences people's preparedness and the way they act, helping anyone to understand the scope of the event and the potential risks that could occur, in order to make informed decisions on how to react. Furthermore, a real understanding of vulnerability influences the resilience of local communities in relation to disasters and can in turn be influenced using social media. Social media can also amplify public fear and concern about the disaster, especially if there is a lot of misinformation or sensationalism about the event. This can lead to an overestimation of risks and an increased sense of vulnerability among the population. These results could be helpful in identifying possible methods and approaches to study these issues in the future.  
Balloon-borne in situ profiles of aerosol, water vapor, and ozone within the Asian summer monsoon anticyclone during the ACCLIP 2022
Authors: Goetz J. Douglas , Kalnajs Lars , Kim Joowan , Norgren Matthew , Kindel Bruce , Kim Hyeong-Gyu , Kang Hyungyu
Published: February 2023

Balloon soundings within the Asian summer monsoon anticyclone (ASMA) were conducted from Osan, South Korea as part of the Asian Summer Monsoon Chemical and Climate Impact Project (ACCLIP) in August of 2022. Over 30 soundings in 12 days were accomplished with high resolution co-located in situ profiles of aerosol size distributions, water vapor, ozone, and state parameters from the surface to the lower stratosphere. Aerosol measurements included accumulation mode particle size and number concentrations with Printed Optical Particle Spectrometers (POPS), coarse mode measurements with LASP Optical Particle Counters (LOPC), and total aerosol between 20 nm and 10 µm with Stratospheric Total Aerosol Counters (STAC). The aerosol sondes observed a pervasive Asian Tropopause Aerosol Layer (ATAL) and temperature dependent microphysical trends that are consistent with the location of the cold-point tropopause and lapse rate minimum. Simultaneous flights with cryogenic frostpoint hygrometers (EN-SCI CFH) and ozonesondes (EN-SCI ECC) provided context on the UTLS mixing processes in the ASMA through tracer-tracer relationships. Model reanalysis products suggest that the soundings were within the ASMA domain and back trajectories indicate sampling of fresh and aged airmasses within the UTLS transported from the ASMA circulation. These measurements add to the limited record of aerosol and water vapor observations of the Asian UTLS during the summer monsoon and provide an understanding of the ATAL that can only be gathered from continuous vertical profiles. 
The dynamics and predictability of US winter extremes—a multiscale case study of the 2021 U.S. cold air outbreak
Authors: Lang Andrea
Published: February 2023

Since 1980, the U.S. experienced 338 different billion-dollar weather and climate disasters, with greater than 25% (n = 96) of these occurring in the cold season of December–March. These events can have lasting societal and economic impacts that make diagnosing their likelihood of occurrence in the next week, season, or decade an important problem in the context of our changing climate. This analysis will focus on a case study of the predictability and dynamics of the 2021 US cold air outbreak (CAO) and provide a multiscale overview of the event on subseasonal-to-seasonal (S2S) timescales. The analysis of the dynamics focuses on the role of the stratospheric recovery from the January 2021 sudden stratospheric warming and a stratospheric Rossby wave reflection event in the context of the development of high amplitude flow in early February 2021. The second part considers the ability of S2S forecast models to resolve the predecessor events to this CAO. The predictability of this CAO and the role of the stratosphere in the development of CAO are considered by analyzing both high-top and low-top S2S forecast model from the S2S prediction Project Database.
A transect of mercury concentrations in fish (Black bass, Micropterus salmoides) from the Valdeazogues river, Almadén Hg mining district, South Central Spain.
Authors: Barquero José Ignacio , Higueras Pablo , Hidalgo Jesus J. , Esbri Jose M. , Lorenzo Saturnino , Garcia-Ordiales Efren
Published: February 2023

The Almadén district has been the World’s largest producer of mercury (Hg), for more than 2000 years. The mining activity in the district ceased some 10 years ago; however, the generalized pollution of soils and stream sediments, as well as the atmospheric emissions from these and other sources, still represent possibilities to toxify the human food chain. The Valdeazogues river crosses completely the district, with some 150 km2 extension, and including a huge mine, three mines of median importance, and up to 60 points where cinnabar (HgS) has been recognized.Largemouth bass (Micropterus salmoides) is a carnivorous freshwater gamefish, very common along the Valdeazogues river. For years it was fished to complement the diet of the local inhabitants, although nowadays is not so common to consume it. We obtained 28 specimens, with sizes between 69 and 335 mm and weight between 11 and 552 gr, in a transect from the El Entredicho open pit to downstream the district (some 36,3 km). The specimens were analyzed using atomic absorption spectrometry with Zeeman effect.Results show important variations throughout the transect; the largest fish in terms of weight and length had the highest Hg concentration (5246 ng/g), much higher than the fish with the lowest concentration (473.2 ng/g), which was not the specimen with the lowest size. Besides, as we go downstream the Valdeazogues River, moving away from the Entredicho Mine (considered to be the main source of contamination), Hg concentrations drops considerably until stabilizing at approximately 1200 - 1500 ng/g.
Spatiotemporal pattern of precipitation in the Pearl River basin, China from 1951 to 2015
Authors: Cai shirong , Niu Kunlong , Mu Xiaolin , Yang Xiankun
Published: February 2023

Precipitation is one of the most important factors in hydrological cycle and climate change. Due to global climate change, the global and regional hydrological cycle has been changed significantly, and the precipitation pattern has changed, which made natural disasters happened more frequent. In this study, we taken the Pearl River Basin as a case study area and used APHRODITE dataset to investigate the spatiotemporal trend of precipitation during the period of 1951-2015 based on six extreme rainfall indices recommended by the WMO. Then, the MK test was used to verify their trend and analyze the temporal and spatial variability. The results indicated that: (1) The annual PRCPTOT in the Pearl River Basin displayed an increasing trend with an increasing rate of 0.019mm/yr. Although the number of annual rainy days was decreasing, the annual SDII exhibited an increasing trend. The annual R95P and RX1day exhibited an increasing trend, but the R95D and CWD showed a decreasing trend. The seasonal PRCPTOT increased in summer and winter, but decreased in spring and autumn. R95P and SDII displayed an increasing trend in four seasons. (2) The annual variation of PRCPTOT increased from west to east, the trend of SDII, R95P and RX1day were similar with PRCPTOT, but the high value of R95D happened in the middle and lower reaches of Xijiang River, and CWD increased from north to south. Except autumn, the seasonal spatial distribution of PRCPTOT, SDII and R95P were similar. In spring and winter, the spatial distribution of PRCPTOT, SDII and R95P increased from west to east, and from north to south in summer, indicating that the Beijiang River basin and Dongjiang River basin had a higher flood risk. (3) MK test of indices shown that the Yunnan-Guizhou Plateau was becoming drier, and the risk of extreme rainfall was increasing in the Beijiang River basin and Dongjiang River basin. The study results are valuable for future water resources management and ecological environment protection in the Pearl River Basin.
Model complexity and Arctic sea ice tipping points – a single column model approach
Authors: Derby Edmund , Pierrehumbert Raymond
Published: February 2023

Some simple models of Arctic sea ice show bifurcations associated with the loss of sea ice under increased surface radiative forcing (Eisenman and Wettlaufer 2009). However, experiments using GCMs typically show a smooth loss of sea ice under increasing CO2. This mismatch adds to uncertainty on the existence of tipping point behaviour in the Arctic and the processes that stabilise or destabilise it from this behaviour.Simple models exhibiting tipping points typically omit many features of the Arctic climate system. Their bifurcations usually arise from the ice-albedo feedback. The purpose of my work is to use a bottom-up hierarchical approach to investigate how additional features of Arctic climate not included in simple models affect the existence of bifurcations in the system.I started with a base ice model (Eisenman and Wettlaufer 2009) and investigate the role of local ice-atmosphere feedbacks using a coupled atmospheric column model. This allowed me to analyse the impact of the following on the possible states for the model to exist in:Changes to the atmospheric temperature profile – particularly the transition from a stable atmosphere with a strong temperature inversion to a less stable atmosphere as the Arctic warms.
Explicitly resolved changes in surface heat fluxes and downwelling longwave radiation.
Changes in low level Arctic clouds – particularly as the atmospheric structure changes.
I also explored the sensitivity of the model to changes and variation in atmospheric heat transport.I will present results of this work and demonstrate how local atmospheric feedbacks affect the stability of tipping points in Arctic sea ice.
Conceptual models of drought risks for Europe: a step towards a systemic perspective on drought
Authors: Cotti Davide , Sabino Siemons Anne-Sophie , Naumann Gustavo , Wens Marthe , de Moel Hans , Blauhut Veit , Stahl Kerstin , Rossi Lauro , Maetens Willem , Toreti Andrea , Hagenlocher Michael
Published: February 2023

In recent years, research on drought risk has expanded to include multiple types of drought hazards, various exposed elements and a multitude of factors that determine the vulnerability of a given system or sector. This has resulted in a call from the scientific community to adopt a systemic risk perspective on drought. However, a thorough understanding of how drought risks manifest, cascade and interact across different systems and sectors is still lacking, and methodological guidance on how to analyse and represent these interdependencies does not yet exist.  In order to explore these gaps, we have developed conceptual models of drought risks for key selected systems and sectors in the European Union. For each system and sector considered (rain fed and irrigated agricultural systems, forest ecosystems, freshwater ecosystems, public water supply, inland water transport and the energy sector), a conceptual model was constructed to depict how drivers and root causes interact to create drought risk. The models are based on the impact chains methodology and are informed by literature review and multiple expert consultations (including a series of validation workshops). Subsequently, the system-specific models were used to build an overarching conceptual model of the critical interdependencies that exist between all the systems and sectors considered. The analysis has revealed that, in each system, drought risks manifest through a complex web of interactions between drivers of risk, which are in part system-specific and in part shared across the systems considered. From this, multiple considerations for drought risk assessment and management can be derived. In particular, special attention should be placed in defining and representing what drought risk is in each system, as the underlying characteristics might greatly differ. Additionally, the use of conceptual models can constitute an important first step for risk assessment, as they contribute to addressing the complexity of drought risks. Finally, the existence of commonalities and interdependencies between systems implies that interventions can and must be designed so as to consider multiple systems at once, thus avoiding maladaptive solutions. In this sense, the conceptual models can serve as entry points for the identification of risk reduction and adaptation measures which go beyond the single-risk and single-sector perspective, thus contributing to a more systemic view on drought risk management and adaptation, as well as highlighting persisting knowledge gaps.
Benefit of Quantum technology for future earth observation from space – gradiometry case
Authors: Romeshkani Mohsen , Müller Jürgen , Knabe Annike , Schilling Manuel
Published: February 2023

A big interest exists in geoscience disciplines to know the mass variations of the Earth with high resolution and accuracy. For monitoring climate change processes at the required level, it is essential to select the appropriate sensor technology and satellite missions. Future satellite missions will strongly depend on the advancement of novel technology and dedicated observation concepts of the Earth's gravitational field.The first objective of this study is to characterize various quantum and hybrid gradiometer concepts and to describe their respective error properties. As a result of their white noise behavior at low frequencies, Cold Atom Interferometry (CAI) accelerometers and gradiometers are perfectly suited as complementary methods to classical electrostatic concepts. Future gravity satellite missions could greatly benefit from accelerometers and gradiometers applying atom interferometry, alone or in some hybrid constellation. The comparison will demonstrate the differences in the spectral behavior as well as the mutual benefit of CAI-based and classical electrostatic gradiometers (as used in GOCE).Using simulated atom-interferometric and hybrid gradient measurements along one or more gradiometer axes in GOCE-like orbits, we determine the gravity field in spherical harmonics coefficients for the various cases and discuss the pros and cons of the selected concepts.We acknowledge the financial support by the DLR project Q-BAGS, ID 50WM2181 and DLR project QUANTGRAV, ID 50EE2220B.
Near-bottom sediment transport during flood events on a small mountainous river
Authors: Meslard Florian , Bourrin François , Balouin Yann , Robin Nicolas
Published: February 2023

Small mountainous rivers provide an important part of the sedimentary inputs to the oceans. The particularity of theses rivers comes from the fact that their inputs take place mostly during brief and intense flood events. While the quantification of fine sediment flux is fairly well known, sandy inputs are very poorly known and field measurements are scarce. River mouth sand discharge is a key variable in the coastal sediment budget as it participates to the coastline evolution and its protection against marine events. Coarse sediments are mainly transported as bedload, making it difficult to estimate with traditional methods such as traps. In this study, a fixed Acoustic Doppler Current Profiler (ADCP Nortek Aquapro 1 MHz) was deployed on a bottom frame, near the mouth of the Têt river (SE France) to estimate near-bottom sediment transport during flood events. In addition, cross sections have been undertaken with a Sontek Hydroboard equipped with a Sontek M9 ADP at different water discharge during several flood events. A calibration of the backscatter index was carried out using gravimetric measurements and granulometric analysis of water samples to estimate the sediment flux and the sand proportion. Sediment fluxes were then compared with the altimetric variations observed from bathymetric surveys. Results allowed to characterize the variability of the boundary layer thickness and the sediment concentrations during flood events. Those results give useful information to estimate sand fluxes from mountainous rivers to the coastal area in a context where these are considered to be low or non-existent compared to large coastal rivers.
3D structural mapping of the Theistareykir geothermal field, NE-Iceland: Fault and fracture connectivity within a volcanically active rift zone.
Authors: Blischke Anett , Hjartardóttir Ásta R. , Gudnason Egill Árni , Ágústsdóttir Thorbjörg , Benediktsdóttir Ásdís , Vilhjálmsson Arnar M. , Þorsteinsdóttir Unnur , Einarsson Gunnlaugur M. , Óladóttir Auður A. , Mortensen Anette K.
Published: February 2023

We present a new structural model of the Theistareykir high-temperature geothermal field, located in NE Iceland within a volcanically active rift zone. Various interdisciplinary geoscientific methods are applied and cross-analyzed. We use remote sensing data, structural and geological surface and subsurface mapping, drone surveys, borehole images, seismicity, potential field, and CO2 surface emissions data. This composite data modelling approach aims to highlight primary fault zones and fractured intervals at the surface by assigning fault types and their spatial orientation. The compiled surface and subsurface datasets were used for 3D fault projections and the delineation of fault-block compartments. Fault plane solutions from earthquakes supported fault property assignments, slip direction, and stress-field orientations. Surface fault segments and fracture intensity maps highlight areas of relay ramping, fault damage, and accommodation zones in between the NW-SE, NE-SW to N-S striking fault systems of the Theistareykir rift segment. The fault systems are intersected by WNW-ESE striking embryonic transfer zones that form boundaries between rift valley graben segments south and within the Theistareykir geothermal field area. These WNW-ESE transfer zones accommodate the differential and oblique opening of the rift zone, which overall follows the right-lateral opening direction of the region south of the Husavik-Flatey transform fault. Our structural model of the Theistareykir geothermal field area is subdivided into six structural domains that form fault block compartments, with varying degrees of faulting and fracturing, reflecting the different quality of hydraulic connectivity across the field.