bluuebunny/crossref_metadata_2025 huggingface dataset:
MSWX: Global 3-Hourly 0.1° Bias-Corrected Meteorological Data Including Near-Real-Time Updates and Forecast Ensembles
Authors: Beck Hylke , van Dijk Albert , Larraondo Pablo , McVicar Tim , Pan Ming , Dutra Emanuel , Miralles Diego
Published: February 2023

We present Multi-Source Weather (MSWX), a seamless global gridded near-surface meteorological product featuring a high 3-hourly 0.1° resolution, near-real-time updates (∼3-h latency), and bias-corrected medium-range (up to 10 days) and long-range (up to 7 months) forecast ensembles. The product includes 10 meteorological variables: precipitation, air temperature, daily minimum and maximum air temperature, surface pressure, relative and specific humidity, wind speed, and downward shortwave and longwave radiation. The historical part of the record starts 1 January 1979 and is based on ERA5 data bias corrected and downscaled using high-resolution reference climatologies. The data extension to within ∼3 h of real time is based on analysis data from GDAS. The 30-member medium-range forecast ensemble is based on GEFS and updated daily. Finally, the 51-member long-range forecast ensemble is based on SEAS5 and updated monthly. The near-real-time and forecast data are statistically harmonized using running-mean and cumulative distribution function-matching approaches to obtain a seamless record covering 1 January 1979 to 7 months from now. MSWX presents new and unique opportunities for hydrological modeling, climate analysis, impact studies, and monitoring and forecasting of droughts, floods, and heatwaves (within the bounds of the caveats and limitations discussed herein). The product is available at www.gloh2o.org/mswx.
Compositional stratigraphy on Mars as evidence of hundreds of millions of years of greenhouse conditions on Mars
Authors: Ye Binlong , Michalski Joseph
Published: February 2023

Chemical weathering is an important indicator of past climate and redox state [1-3]. On Mars, weathering profiles may have formed in basaltic sediments or volcanic ash that were altered by surface water and were subsequently buried and persevered in the geological record. Orbital remote sensing of the global Martian surface has detected dioctahedral clay minerals within Noachian layered sedimentary rocks, which are consistent with the precipitation-driven pedogenic weathering of mafic sediments [1]. Noachian sedimentary rocks with spectral signatures of subaerial weathering have been detected in thousands of locations across the surface of Mars [1,4].In this study, orbital imagery, spectroscopy, topographic data and crater chronology are investigated to explore the geologic context, stratigraphy, and relative age of >200 weathering profiles across the Martian southern highlands [4]. The youngest might be Early Hesperian, although virtually all are older than 3.7 Ga. Weathering profiles exist across a wide range of elevations (>11 km), from −5 to 6 km, indicating they developed as a result of top-down, precipitation-driven chemical weathering and this was a global phenomenon. We discovered that almost all exposures show a similar, single stratigraphic relationship of Al/Si material overlying Fe/Mg clays, rather than several, interbedded mineralogy transitions. This points to either a single warming event or, more likely, a chemical resetting scenario in which the most recent event overprints the prior weathering pattern. The time necessary to develop a typical profile is estimated to be several million years, which corresponds to only a portion of the Noachian period. As a result, the broad estimated age span ~700–800 My appears incompatible with a single climate excursion. We consider that the presence of weathering profiles in many geologic units at a wide range of ages over a long period of geologic time and at a wide range of elevations, suggests a top-down, precipitation-driven chemical weathering was global in scope. Fe-mobility was a crucial component of chemically weathering, which happened geologically rapidly under anoxic conditions that might potentially warm the martian surface via reduced greenhouse gas. Collectively, these results indicate that multiple weathering episodes are driven by multiple reduced greenhouse conditions on ancient Mars.[1] Carter et al. 2015, Icarus, 248, 373-382. [2] Bishop et al., 2018, Nature Astronomy, 2(3), 206-213. [3] Liu et al., 2021, Nature Astronomy,5(5), 503-509.[4] Ye & Michalski, Communication Earth & Environments, 3(1), 1-14.
Assessing the impacts of future climate change scenarios on water systems supplied by karst aquifers
Authors: Peres David J. , Palazzolo Nunziarita , Mineo Claudio , Passaretti Stefania , Boscariol Eleonora , Varriale Anna , Cancelliere Antonino
Published: February 2023

Water resources management is becoming increasingly challenging under current climate change. Water utilities need to assess planning adaptation strategies aimed at sustainable water resource exploitation. In this study, we estimate the potential impacts of climate change on hydrological variables and future spring discharge availability. Specifically, we exploit an empirical regressive model based on the statistical relationship between Standardized Precipitation-Evapotranspiration Index (SPEI) and minimum annual spring discharge, in combination with Regional Climate Models (RCMs) provided by the EURO-CORDEX initiative. In this regard, two Representative Concentration Pathways (RCPs) are considered, RCP4.5 (intermediate emissions scenario) and RCP8.5 (high emissions scenario), as well as two future time horizons, namely the near future 2021-2050 and the far future 2041-2070. Then, after bias correction of the so estimated minimum spring discharge values, the curves relating spring discharge and reliability in satisfying water demand are assessed. We carried out our investigation for karst aquifers located in the Italian Apennines, which are used for the water supply system of the city of Rome (Italy) and the surrounding areas, managed by ACEA Ato2, serving over 4 million users. Overall, the results indicate a general decrease in the demand that can be satisfied with high reliability, pointing out significant potential impacts of climate change on water availability on both near and far future. The proposed methodology could be a useful tool for water managers, since it provides a support for planning adaptation measures aimed at minimizing future socio-economic impacts of climate change.
Feeding 10 billion people and achieving negative emissions within Planetary Boundaries – insights from global modelling
Authors: Gerten Dieter , Braun Johanna , Breier Jannes , Schaphoff Sibyll , Stenzel Fabian , Werner Constanze
Published: February 2023

This talk will present key results from a suite of comprehensive simulations performed with a configuration of the LPJmL biosphere model able to represent the dynamic and spatially detailed status of terrestrial Planetary Boundaries (PBs, i.e. guardrails describing maximum tolerable levels of land-system change, biosphere degradation, freshwater use and nitrogen leaching to avoid Earth system destabilisation).An application of the PB simulator addresses the question how much food could be supplied globally while respecting these multiple PBs, and to what degree this supply could be increased through transformative actions towards more sustainable food production and consumption patterns. A further application demonstrates the potential to achieve ‘negative emissions’ through dedicated biomass plantations (as a measure to limit transgression of the climate change PB) within these PBs. A main finding is that almost half of current food production is environmentally unsustainable in that it depends on PB transgressions. Subsequent simulations show that the same amount of food presently produced under these unsustainable conditions, and even up to about 50% more, could be provided without violating the PB constraints in any place. This would be sufficient to feed around 10 billion people. The required underlying transformations of the food system are rather radical though: ambitious prerequisites are more efficient use of freshwater and nitrogen fertiliser in many places, reallocation of rainfed and irrigated cropland to areas where that would still be acceptable from a PB point of view, halving of food losses, dietary shifts towards lower shares of animal-based products, and (importantly) combinations thereof.While this poses grand challenges regarding transformation of world agriculture and optimisation of resource use, currently debated methods to achieve ‘negative emissions’ via large-scale deployment of biomass plantations are likely to require large areas as well as freshwater and nutrients on their own. We will show that the option space for such measures is therefore actually very limited, if the terrestrial PBs were to be maintained. In addition, PB interactions such as ongoing and aggravating climate change including more frequent and intense droughts may seriously affect both the food production and negative emissions potentials. A conclusion is that quantitative robust understanding of these major tradeoffs and dilemmas requires even more comprehensive and integrated nexus studies bringing together the relevant aspects in a consistent PB modelling framework, not least also accounting for the social dynamics underlying the required transformations in the real world.
Frequency dependent attenuation and relative site response of western Tibet
Authors: Singh Chandrani , Tiwari Ashwani Kant , Sandvol Eric , Bose Shirish , Jaiswal Namrata , Jana Niptika , Gupta Arun Kumar
Published: February 2023

We have formulated frequency dependent Lg and Pg attenuation tomographic models to investigate thecrustal Q values and its tectonic implications beneath western Tibet. The frequency dependentbehaviour of both Lg and Pg are studied for the frequency bands of 0.2-0.6, 0.6-1.0 and 1.0-1.4 Hz atcentral frequencies of 0.4, 0.8, and 1.2 Hz, respectively, implementing both Two-Station Method(TSM) and Reverse Two-Station Method (RTSM). The amplitudes of both the waves are fundamentallysensitive to the crustal structures and are controlled by both scattering and intrinsic attenuation. Thefrequency dependent characteristics of QLg and QPg are consistent in nature for the region. Moderate tohigh Q values evident in the Lhasa terrane could supplement the trace of underthrusting Indianlithosphere beneath the region. The average Q values for both Lg and Pg increase with increasingfrequency. The frequency dependent parameter η shows quite high values, for both the waves usingTSM and RTSM, which may indicate strong heterogeneities present in the crust. Subsequently, relativesite responses at each station are studied using RTSM for the central frequencies of 0.4, 0.8, and 1.2Hz. Weak to negative site responses are mostly dominant in western Tibet. Relative site responses arefound to vary with frequency which could be associated with the sampling depth. We found nocorrelation of site responses with the elevation.
Towards global quantification of seawater circulation in coastal aquifers
Authors: Levy Yehuda , Kiro Yael
Published: February 2023

Submarine groundwater discharge (SGD) is significant to coastal water chemistry and ecology. Nonetheless, the majority of SGD flux to the ocean comprises circulated seawater. This study deals with seawater circulation in coastal aquifers on a global scale in order to assess solute fluxes through SGD into the ocean. While the circulated seawater does not affect the water budget, it has a much higher impact on the ocean solutes budget due to water-rock interactions. We present a global assessment of saline SGD mechanisms' role using numerical simulations and analytical calculations. The numerical model simulates three main circulation mechanisms in coastal aquifers: density-driven circulation (long-term), tidal-driven nearshore circulation, and tidal pumping (short-term), while we calculate the wave-driven benthic exchange flux analytically using the same settings of the numerical model. The model tests the typical range of geohydrological parameters such as hydraulic conductivity, hydraulic gradient, tidal amplitude, and more. Our results revealed that: (1) increasing hydraulic conductivity increases the density-driven and decreases the tidal-driven nearshore circulations; (2) increasing the hydraulic gradient (or freshwater recharge) has no significant effect on the density-driven circulation while it slightly decreases the short-term nearshore circulation; (3) tidal pumping fluxes are a relatively large fraction of the overall SGD flux (30%-60%). Together with global hydraulic parameter distributions, the model results enable assessing the global SGD component of seawater circulation. Preliminary results reveal that the total density-driven SGD is about 0.5-1% of the river fluxes to the oceans. Based on the enrichment of calcium in the long-term SGD component, our global assessment of the calcium flux through density-driven flow may reach the same calcium flux through rivers into the ocean. 
Modelling soil organic carbon stocks and greenhouse gases in European forests with multi-model ensembles
Authors: Bruni Elisa , Guenet Bertrand , Abramoff Rose , Manzoni Stefano , Khurana Swamini , Tupek Boris
Published: February 2023

State-of-the-art soil models can be used to monitor and predict the evolution of soil organic carbon (SOC) stocks and greenhouse gas (GHG) fluxes at national, sub-national, and supernational levels. This can help predict the effect of disturbances on the soil and facilitate the development of sustainable management practices to prevent further soil degradation and GHG losses under climate change.However, model simulations are still highly uncertain due to many factors. For instance, the lack of understanding of many soil processes, the way processes are represented in the models, and the parametrization, initialization, and forcing variables used to run them. One way to consider these uncertainties is to use multi-model ensembles, thus simulating the evolution of SOC stocks and GHG fluxes according to models with different structures and mechanistic assumptions.In this work, we show a webtool that enables the simulation of SOC stocks and GHG gases in European forests under different climate and land-use change scenarios, using a multi-model ensemble. In the absence of on-site measurements, the webtool directly accesses online databases of pedo-climatic data that is required to run the models.Models also need to be correctly parameterized and evaluated before their application. For that, we build a map of model parameters that can be used to force the models, and which is evaluated on the European LUCAS database. Uncertainties linked to the initialization method used are also discussed.
Cover Crops Affecting Pool Specific Soil Organic Carbon Sequestration in Cropland – A Meta-Analysis
Authors: Fohrafellner Julia , Zechmeister-Boltenstern Sophie , Murugan Rajasekaran , Keiblinger Katharina , Spiegel Heide , Valkama Elena
Published: February 2023

Greenhouse gas emission can be partly compensated by enhancing soil organic carbon (SOC) levels in soils, e.g. in croplands, which have the highest potential due to their losses in SOC by intensive management. This can be achieved by adopting SOC enhancing soil management practices, such as the cultivation of cover crops (CC). So far, only few long-term experimental studies have investigated the effects of CC on a SOC pool level. There are still uncertainties how CC affect SOC fractions and the stability of the sequestered carbon.By conducting a meta-analysis, we aim to quantitatively summarize studies related to CC effects on SOC pools throughout soil depths (up to 100 cm) in cropland soils relevant for Europe, as such an analysis is not available so far. We included global studies located in the dry, temperate, and boreal climatic zones, as these are present Europe. The pools chosen for this analysis are the microbial biomass carbon (MBC), the particulate organic matter (POM) and the mineral associated organic matter (MAOM) pool, as well as total SOC. Alongside, we study the effects of a broad range of moderators, such as pedo-climatic factors (e.g., climatic zones, soil texture), other agricultural management practices (e.g., effects of tillage, irrigation, liming, fertilization) and CC characteristics and their management (e.g., CC types, species number, frost resistance, residue management).By searching several scientific and grey literature databases, we identified 64 studies, of which the majority was conducted in North and South America, whereas only five are available for Europe. The MBC, POM and MAOM pool are studied in 24, 44 and 19 of these studies, respectively. The mean experimental duration is eight years, with a maximum of 39 years. 54% of studies were conducted in a warm temperate climatic zone, 32% in a boreal and 14% in an arid zone. Means values for SOC pools, standard deviations and sample sizes for treatments with CC and controls without CC will be extracted from tables and figures. In order to perform a meta-analysis, logarithm response ratio as an index of effect size will be calculated for each study, which will then be summarized across studies by using weighing procedure. This meta-analysis will provide valuable information on the state of knowledge on SOC pool specific sequestration rates influenced by CC, corresponding quantitative summary results and the source of heterogeneity across studies. These results will offer guidance for future research and assist decision-making processes regarding climate friendly management of agricultural soils.
Changes of drought vulnerability in the 21st century - the case study of the Vistula catchment in Poland
Authors: Karamuz Emilia , Senbeta Tesfaye , Bogdanowicz Ewa , Napiórkowski Jarosław
Published: February 2023

The ongoing climate change disrupts the water cycle and alters the hydrometeorological patterns at global and regional scales. The alarming intensification of droughts in Europe in recent decades may become the future new norm.This study aims to assess the future spatio-temporal drought variability in the River Vistula basin, the largest river in Poland. This basin’s vulnerability to drought is also investigated. Two drought indices, namely the Standardized Precipitation Index (SPI) and Standardized Precipitation Evapotranspiration Index (SPEI) are evaluated using the observed climatic data and meteorological projections for the 21st century. These projections of climatic variables are obtained from the EURO-CORDEX initiative based on fourteen climate models for the period 1971–2100 for the RCP4.5 and RCP8.5 emission scenarios. Drought vulnerability analysis is carried out by combining exposure, adaptive capacity and sensitivity metrics, using the vulnerability scoping diagram (VSD) method.Preliminary results show that projected changes in precipitation and air temperature result in significant variations in temporal drought patterns in the River Vistula basin. The divergent results were obtained for the two analysed drought indices. The SPEI projections indicate drier conditions in the basin to be expected in the far-future period, whereas the SPI indicates wetter conditions. The analysis shows that areas in the central and southern parts of the basin are more vulnerable to drought.AcknowledgementsThis work was supported by the project HUMDROUGHT, carried out in the Institute of Geophysics Polish Academy of Sciences and funded by National Science Centre (contract 2018/30/Q/ST10/00654).
Countrywide characterization of forest edge structure from airborne laser scanning data
Authors: Bruggisser Moritz , Wang Zuyuan , Waser Lars T.
Published: February 2023

Forest edges represent the transition zone between the open country side and the forest interior. Ideally, the edge zone consists of a shrub belt (vegetation height < 4 m) and a shelterbelt with a distinct height gradient towards the forest interior. Forest edges provide several ecological functions. They offer habitats for plant and animal species, regulate fluxes of nutrients and pollutants between surrounding agricultural areas and the forest, or regulate the microclimate. Repeated assessment of forest edge conditions will help forest owners the maintenance of these edge functions considering the increased pressure due to e.g., intensified agriculture.The aim of the ongoing project is to provide a map of forest edge structure characterization for entire Switzerland (total forest edge length 186’773 km). We used the latest freely available full coverage airborne laser scanning (ALS) data, which provides point densities of 15-20 points/m2 and a forest mask provided by the Swiss National Forest Inventory (NFI). The high point densities allowed to assess both the horizontal and the vertical structure of the forest edges. On the one hand, we extracted information on the edge composition which is closely related to parameters extracted within NFIs. These comprise detailed information on the shelterbelt composition including its slope, presence or absence of the shrub layer and detection of overhanging trees. Furthermore, we computed the vegetation height distribution and the number of vegetation layers within the edge zone. On the other hand, ALS data was used to compute additional features such as the horizontal canopy cover and canopy gaps, the vertical canopy density, and the 3D light availability within the forest edge zone.We followed a sampling-based approach and characterized the forest edge structure for discrete sampling points at the edge of the forest mask. The forest edge zone covers an area of +/- 25 m along the forest mask from the sample point and +/- 30 m into and outside of the forest, respectively, measured perpendicular to the forest mask edge. Validation of the derived parameters is based on more than 300 terrestrial NFI plots comprising forest edges. This discrete sampling-based forest edge characterization map could potentially be transferred into a quasi-continuous forest edge description by increasing the number of sampling-points on the forest edge.Repeated six-yearly ALS acquisitions by the Federal Office of Topography swisstopo will enable to produce regular forest edge characterization data sets as a basis for the monitoring of the forest edge development at a countrywide extent. This will help to identify forest edge areas which are at severe threat of degradation and thus require treatment intervention. Thereby, the quality of forest edges can be preserved or improved for important ecosystem services.
A web-based strategy to reuse grids in geographic modeling
Authors: He Yuanqing , Chen Min , Wen Yongning , Yue Songshan
Published: February 2023

Integrated application of geo-analysis models is critical for geo-process research. Due to the continuity of the real world, the geo-analysis model cannot be applied immediately over the entire space. To date, the method of regrading space as a sequence of computing units (i.e. grid) has been widely used in geographic study. However, the model's variances in division algorithms result in distinct grid data structures. At first, researchers must install and setup the various software to generate the structure-specific grid data required by the models. This method of localized processing is inconvenient and inefficient. Second, in order to integrate the models that use different structural grid data, researchers need to design a specific conversion method based on the integration scenario. Due to difference of researcher’s development habits, it is difficult to reuse the conversion method in another runtime environment. The open and cross-platform character of web services enables users to generate data without the assistance of software programs. It has the potential to revolutionize the present time-consuming process of grid generation and conversion, hence increasing efficiency.Based on the standardized model encapsulation technology proposed by OpenGMS group, this paper presents a grid-service method tailored to the specific requirements of open geographic model integration applications, and the research work is carried out in the following three areas:The basic strategy of grid servitization. The heterogeneity of the grid generation method is a major factor that prevents it from being invoked via a unified way by web services. To reduce the heterogeneous of the grid generation method, this study proposes a standardized description method based on the Model Description Language (MDL).
Method for constructing a grid data generating service. A unified representation approach for grid data is proposed in order to standardize the description of heterogeneous grid data; an encapsulation method for grid generating algorithms is proposed; and grid-service is realized by merging the main idea of grid servitization.
Method for constructing a grid data conversion service . A box-type grid indexing approach is provided to facilitate the retrieval of grid cells with a large data volume; two conversion types, topologically similar and topologically inaccessible grid data conversion, are summarized, along with the related conversion procedures. On this foundation, a grid conversion engine is built using the grid service-based strategy as a theoretical guide and integrated with the grid conversion strategy.
Based on the grid service approach proposed in this paper, researchers can generate and converse grid data without tedious steps for downloading and installing programs. Thus, there are more time spend on geography problem solving, hence increasing efficiency.
The 2021-2022 unrest phase of Vulcano Island volcanic system (Aeolian islands): chemical and isotopic evolution of low-to-high temperature fluid discharges and waters from thermal and cold wells.
Authors: Tassi Franco , Capecchiacci Francesco , Vaselli Orlando , Venturi Stefania
Published: February 2023

In summer 2021, a progressive increase of seismic activity and ground deformation was recorded at Vulcano (Aeolian Islands), followed by a strong change in fumarolic gas emission started in September 2021. New gas vents appeared on the crater rim and along the northern outer flank of the La Fossa crater with outlet temperatures up to 350 °C, and a general increase of CO2 and SO2 fluxes was measured.In this study, we report the results of a geochemical monitoring, including gas and water samples collected during 5 field campaigns, carried out from November 2021 to October 2022. The main aim was to verify the evolution of the plumbing system feeding the fluid discharges of the Vulcano summit crater and those located in the Baia di Levante area. The geochemical dataset also includes the chemical and isotopic composition of thermal and cold wells located in the Vulcano Village. The analytical results have shown that in November 2021 and February 2022 the 9 selected crater fumaroles were affected by a strong increase, compared to the previous decade, of the (i) concentrations of acidic gases of marked magmatic origin (SO2, HCl and HF) and temperature-dependent gases (H2 and CO) (ii) gas/vapor and (iii) SO2/H2S ratios. In this period, the chemistry of waters and dissolved gases from the wells located at the foothill of the volcanic cone, and that of the gas discharges at Baia di Levante did not show significant anomalies.Since June 2022, the SO2/H2S ratios as well as the concentrations of magmatic gases, H2, and CO decreased, concurrent with a general decrease of the fumarolic flux. At Baia di Levante an opposite evolution was observed mainly consisting of a significant increase in H2S, H2, and CO accompanied by a decrease in CH4 concentrations. Such compositional changes were marked by the occurrence of seawater whitening events caused by enhanced emission of sulfur-rich fluids. In this period, the temperature, as well as the SO4/Cl ratios and the concentrations of dissolved CO2 in the thermal wells of the Vulcano Village also increased. The chemical-physical evolution of the crater fumaroles, culminated in February 2022, was likely related to a strong pulse of magmatic fluids occurred in summer 2021. The fluid reservoir feeding the discharges at the periphery of the magmatic fluid plumbing system, the latter being directly connected to the crater fumaroles, seems to have buffered the pulse until May 2022, when the heat and magmatic fluids fed by the deep source partially bypassed the hydrothermal aquifer. Further observations related to the continuation of the geochemical and geophysical monitoring of the Vulcano hydrothermal-magmatic system in the next months could provide fundamental insights to confirm the decline of the volcanic crisis as suggested by the recent evolution of the crater gas chemistry.
Identifying contributions of multi- recharge sources to streamflow by using a stepwise approach based on isotopic and hydrochemical signals in a glacierized catchment over Tibetan Plateau
Authors: Li Guangxuan , Chen Xi , Gao Man , Wang Yuyi
Published: February 2023

Streamflow in the glacierized catchments over the Tibetan Plateau receives multi-recharge sources, such as rainfall, melt water from snowpack and glacier, and groundwater. Identifying their contributions to streamflow is challenge but it is vital for understanding streamflow and its composition in response to climate change. In this study, based on high-resolution isotopic (18O) and hydrochemical (Cl-) data in the Yangbajing (YBJ) catchment of the Tibetan Plateau in China, we found that the hydrograph in a year can be separated into five segments, each of which is constituted of two or three dominant recharge sources. Thus, we developed a stepwise EMMA (end-member mixing analysis) method to partition the hydrograph and calculate contributions of water sources to streamflow in each segment of the hydrograph. Results show that the overall contributions of deep and shallow groundwater, melt water from glacier and snowpack, and precipitation are 21.8%, 9.8%, 37.5%, 8.5% and 22.4%, respectively, in a year. Specifically, in the low flow period (January 8 - April 26), streamflow is fed by deep and shallow groundwater (75.2% and 24.8%, respectively). In the early rising period of hydrograph (April 27-June 9) when temperature begins to rise, streamflow fed by deep groundwater decreases and its contribution by snow melt water increases (52.5% and 47.5%, respectively). In the fast-rising period (June 10-June 30), streamflow fed by deep groundwater is minor (4.8%) while snow and glacier melt water becomes the dominant recharge sources to the stream water (52.8% and 42.4%, respectively). In the summer period of July 1- September 23, the streamflow is highest, and the greatest glacier melt water and rainfall contributes to 52.4% and 36% of the stream flow, respectively. In the recession period (September 24 - January 7) when temperature drops and rainfall ceases, streamflow is fed again by deep groundwater and shallow groundwater (45.7% and 54.3%, respectively).
Characterization of surface flow using Lagrangian drifter for particle tracking model applications.
Authors: Demmer Jonathan , Neill Simon
Published: February 2023

Accurate ocean data (i.e., tide, current velocity and direction, wave) are essential for numerous environmental studies: 1) development of marine renewable energy (e.g., maximize the efficiency of energy conversion); 2) aquaculture (e.g., offshore development); 3) anthropic pollution (e.g., plastic/pollutant dispersal); and 4) ecology (e.g., spread of invasive species).The exponential increase of computational power has made numerical models, such as Eularian hydrodynamic models and Lagrangian particle tracking models (PTM) useful tools to characterize physical oceanographic parameters. However, methods to validate PTMs appear less developed due the complexity of biophysical process interactions; for example, uncertainty remains on the impact of wind on surface currents and how the effects of wind are propagated through the water columnHere, we use a novel set of data representing the travel of drifters in the Irish Sea during two consecutive years (summer 2021 and 2022). The experiment aim is to reduce the near surface flow uncertainty influencing particle dispersal. Data were collecting using a range of drifters released in coastal and offshore locations of a tidally dominate shelf-sea (Irish Sea): 1) variation of drogue depth between 1m and 5m; 2) variation of period from tidal cycles to spring-neap cycles; and 3) some with reduced “windage” designs (no drogue and minimal exposure above surface).Preliminary results show the importance of wind driven current between the surface and 5 m depth, which should be take into account when considering the development of PTM. Furthermore, we find some scales of oceanographic processes that affect transport, such as turbulent eddies and waves, were not resolved - and yet our predictions broadly matched observations.
Impacts of wildfire and drought on hydrological connectivity and solute dynamics in a temperate blanket peat catchment
Authors: Marcotte Abbey L. , Limpens Juul , Nunes João Pedro , Khamis Kieran , Krause Stefan , Ullah Sami , Kettridge Nicholas
Published: February 2023

Intact peatlands provide crucial ecosystem services, regulating discharge by retaining water and providing high water quality by retaining solutes. These services can become compromised when peatlands become degraded by natural disturbances such as wildfire and drought. Such disturbances in traditionally non-fire prone regions will likely become more frequent and severe under future climates, potentially impacting downstream water quality. Understanding how fire and drought alter hydrological and biogeochemical processes in these regions is necessary for future risk assessment.The 2018 Saddleworth moorland wildfire (England) offered a unique opportunity to study the combined impacts of severe wildfire and drought on stream water quality fed from a peatland-dominated catchment in a traditionally non-fire prone region (i.e., northern Europe). Capitalising on this event, our study aimed to (1) quantify stream chemistry changes and (2) understand patterns of element mobilisation and transport within the disturbed catchment. We evaluated concentration-discharge (C-Q) responses for nine variables (dissolved organic carbon, sulphate, Na, Ca, Pb, Zn, Al, Cu and turbidity) in five post-fire storm events over a nine-month period. C-Q responses were considered together with hysteresis and flushing indices (HI and FI, respectively) to further describe solute dynamics within storms.Highest average concentrations of nutrients and base cations occurred in the storms immediately following the wildfire (~0 – 3 months post-fire) and average concentrations decreased into the autumn and spring (~3 – 9 months post-fire). In contrast, average metal concentrations began increasing in autumn and into the spring storms, coinciding with the timing of catchment re-wetting. Element behaviour patterns inferred from C-Q responses and HI/FI indices suggest rapid mobilisation and flushing of nutrients and base cations following the wildfire, and a shift to dilution behaviours in the spring storms. This shift indicates a change from surface transport and an exhaustion of readily available burnt materials. Metals consistently displayed delayed mobilisation, where concentrations peaked after the discharge peak, indicating a within-peat or distal headwater sources.Our results suggest that seasonal re-wetting and rejuvenated hydrologic connectivity of the catchment following extreme drought was a dominating factor controlling source zone activation, mobilisation and transport of solutes in our catchment. Additionally, water quality impacts appeared to be limited to the first ~3 months following the wildfire, suggesting certain aspects of wildfire impacts in temperate peatlands may be short-lived. Our results contribute to defining potential water quality risks in drought and wildfire disturbed peat catchments under future climates.
An atypical swarm at the North Mid-Atlantic ridge indicating spreading events
Authors: Cesca Simone , Metz Malte , Büyükakpınar Pınar , Dahm Torsten
Published: February 2023

A large seismic swarm affected the North Mid-Atlantic ridge between September and November 2022, with an outstanding seismicity rate and a cumulative moment equivalent to a magnitude Mw 6.3. We performed a detailed seismological analysis using regional, teleseismic and array data to reconstruct the spatiotemporal evolution of the seismicity. Combining template matching, relative location and full moment tensor inversion, we identify that most seismicity was located in a narrow band along the ridge, with typical normal faulting mechanisms. However, some of the latest and strongest events occurred up tp 25 km off the ridge axis, with thrust mechanisms that are atypical at mid-ocean ridges and inconsistent with the extensional tectonics. Seismicity also present a clear migration pattern, propagating over ~60 km from North to South, with the thrust mechanisms only occurring in the late phase of the swarm and only in the central-southern section. We hypothesize a magmatic intrusion as driver of the seismicity, with a vertical dyke first propagating southward, accompanied by normal faulting earthquakes, and then thickening, to produce a stress perturbation able to trigger thrust earthquakes on pre-existing structures on the side of the dike. The 2022 unrest provides evidence for sporadic spreading accompanied by large swarm episodes driven by magma intrusions at the mid-ocean ridge.
Assessment of the agronomic impact of rice husk ash, volcanic ash, green compost and wood biochar as soil amendments
Authors: De la Rosa José María , Pérez-Dalí Sara , Miller Ana Z. , Campos Paloma , Sánchez-Martín Águeda , Cubero Beatriz , Jiménez-Morillo Nicasio T. , Merino Agustín , González-Pérez José Antonio
Published: February 2023

Today's agriculture faces the challenge of guarantee food supply of a growing population while human activity has already degraded nearly 40 % of the world's soils [1], which lose productive capacity and increase dependence on mineral fertilizers. In this context, the valorization and recycling of mineral and agricultural waste for use as substrates or soil amendments promotes the local and sustainable economy as well as the implementation of activities based on closing the soil nutrients’ cycle. Moreover, pyroclastic rocks and volcanic ashes formed by volcanic eruptions are usually rich in Si, Ca, Mg, Al, Fe, K, P and S [2], so they can be used in agriculture as inorganic mulch. Looking for an effective solution to the great waste generation and the current challenges of sustainable agriculture [3], this study addresses the agronomic effects of the application of contrasting inorganic and organic materials including green compost, wood biochar, rice husk ash and volcanic ash released in the recent eruption of the Tajogaite volcano (La Palma Island, Spain) as amendments of an alkaline soil typical of the Mediterranean basin. For this purpose, barley seeds were planted and grown under controlled conditions in a greenhouse for 60 days on a Luvisol amended with the above-mentioned materials.The organic amendments improved soil physical properties, such as the reduction of bulk density and of the soil resistance to penetration, and increased the organic carbon content. Biochar increased the amount of refractory organic matter of the Luvisol. The application of rice husk ash, volcanic ash, and to a lesser extent the green compost, increased the nutrient content of the soil. Nevertheless, no significant differences were observed on germination rates, productivity and abiotic markers of stress of the barley plants.Acknowledgements: Authors thank the financial support from the Spanish Ministry of Science and Innovation (MCIN) under the projects RES2SOIL (PID2021-126349OB-C22) and TUBOLAN (PID2019-108672RJ-I00) supported by MCIN and AEI. The European Joint programme EJP SOIL funded from the EU Horizon 2020 research and innovation programme (Grant agreement Nº 862695) is also thanked for funding the subproject EOM4SOIL.References:[1] Gibbs, H.K., Salmon, J.M., 2015. Appl. Geogr. 57: 12-21.[2] Ramos, C.G., Querol, X., Dalmora, A.C., Pires, K.C.J., Schneider, A.H., Oliveira, L.F.S., Kautzmann, R.M., 2017. J. Clean. Prod., 142: 2700-2706.[3] De la Rosa, J.M., Campos, P., Diaz-Espejo, A., 2022. Agronomy, 12: 2321. https://doi.org/10.3390/agronomy1210232
Insights on methane emissions using GHGSat’s constellation
Authors: Strupler Mathias , Girard Marianne , Jervis Dylan , MacLean Jean-Phillipe , Marshall David , McKeever Jason , Ramier Antoine , Young David
Published: February 2023

In May 2022, GHGSat added 3 satellites to its growing methane monitoring constellation, bringing the total to 5 commercial satellites now in operation. Each satellite has a detection threshold of about 100 kg/h and a 25 meters spatial resolution, enabling them to attribute industrial emissions to individual facilities. With its constellation, GHGSat can measure any site in the world with a repeatable methodology multiple times per year, giving a unique view of localized methane emissions on a global scale.
This presentation will focus on the insights that can be obtained from aggregate industrial methane emissions data measured by the GHGSat constellation. Example use cases ranging from local to global monitoring will be presented. In addition, we will discuss the constellation’s imaging capabilities and current methane measurement accuracy. Finally, an update on the next phase of the constellation will be given.
Assessment of compound extremes using statistical methods in India
Authors: Sahoo Tapobeeva , Bejagam Vijaykumar , Sharma Ashutosh
Published: February 2023

Extreme events are becoming more frequent, intense, and prolonged, with significant impacts on human lives, the environment, and regional development. Rising temperature due to global warming is one the crucial factors causing the rise in the frequency and severity of extreme events. The worst extreme events are caused by a combination of more than one factor/variable, which makes it essential to study the co-occurrences of extremes, also known as compound extremes. In the present study, four compound extremes are assessed over India for the time period of 1971-2020 using two different statistical approaches, empirical approach, and multivariate distribution analysis. The variables used are temperature and precipitation, having a resolution of 0.25° × 0.25°. Firstly, the empirical analysis of four compound extremes, Hot-Dry, Hold-Wet, Cold-Dry, and Cold-Wet, is done by providing threshold percentiles (25th and 75th) to count the exceedance, and Mann Kendall's trend, p-value, and Sen's slope are calculated to assess the changes and significance of the extremes. Next, multivariate distribution analysis using Copula is conducted to study the dependency between temperature and precipitation. The results indicate a significant increase in compound Hot-Dry and Hot-Wet extremes across the country, with a decrease in Cold-Dry and Cold-Wet conditions. The changes in extremes are more pronounced in the later period (1996-2020) than in the earlier period (1971-1995). This study provides insight into the evaluation of compound extremes in India over the past 50 years, which can help us understand the changes and frequency of their occurrence.
Convection and Clouds under Different Planetary Gravities Simulated by a Small-domain Cloud-resolving Model
Authors: Liu Jiachen , Yang Jun , Zhang Yixiao , Tan Zhihong
Published: February 2023

In this study, we employ a cloud-resolving model (CRM) to investigate how gravity influences convection and clouds in a small-domain (96 km by 96 km) radiative-convective equilibrium (RCE). Our experiments are performed with a horizontal grid spacing of 1 km, which can resolve large (> 1 km2) convective cells. We find that under a given stellar flux, sea surface temperature increases with decreasing gravity. This is because a lower-gravity planet has larger water vapor content and more clouds, resulting in a larger clear-sky greenhouse effect and a stronger cloud warming effect in the small domain. By increasing stellar flux under different gravity values, we find that the convection shifts from a quasi-steady state to an oscillatory state. In the oscillatory state, there are convection cycles with a period of several days, comprised of a short wet phase with intense surface precipitation and a dry phase with no surface precipitation. When convection shifts to the oscillatory state, water vapor content and high-level cloud fraction increase substantially, resulting in rapid warming. After the transition to the oscillatory state, the cloud net positive radiative effect decreases with increasing stellar flux, which indicates a stabilizing climate effect. In the quasi-steady state, the atmospheric absorption features of CO2 are more detectable on lower-gravity planets because of their larger atmospheric heights. While in the oscillatory state, the high-level clouds mute almost all the absorption features, making the atmospheric components hard to be characterized.
An idealized model to assess the impact of gravity waves on ice crystal populations in the Tropical Tropopause Layer
Authors: Corcos Milena , Hertzog Albert , Plougonven Riwal , Podglajen Aurélien
Published: February 2023

The role of gravity waves on microphysics of tropical cirrus clouds and air parcel dehydration was studied using the combination of Lagrangian observations of temperature fluctuations and a 1.5 dimension model. High frequency measurements during isopycnal balloon flights were used to resolve the gravity wave signals with periods ranging from 15min to a few days. The detailed microphysical simulations with homogeneous freezing, sedimentation and a crude horizontal mixing represent the slow ascent of air parcels in the Tropical Tropopause Layer. A reference simulation describes the slow ascent of air parcels in the tropical tropopause layer, with nucleation occurring only below the cold point tropopause with a small ice crystals density. The inclusion of the gravity waves modifies drastically the low ice concentration vertical profile and weak dehydration found during the ascent alone: numerous events of nucleation occur below and above the cold point tropopause, efficiently restoring the relative humidity over ice to equilibrium with respect to the background temperature, as well as increase the cloud fraction in the vicinity of the cold-point tropopause. The increased ice crystal number and size distribution agree better with observations.