bluuebunny/crossref_metadata_2025 huggingface dataset:
Groundwater availability and sustainability
Authors: de Graaf Inge
Published: February 2023

Groundwater is het largest available freshwater resource on earth and is critical to humans and the environment. Groundwater is especially important for irrigated agriculture, and thus for global crop production and food security; approximately 40% of the today’s irrigated agriculture depends on groundwater. In many regions around the world, unsustainable groundwater pumping exceeds recharge from precipitation and rivers. This leads to substantial drops in groundwater levels and losses of groundwater from its storage, especially in intensively irrigated regions, as well as reduction of river flows with possible devastating impacts on freshwater ecosystems.In my research I simulate groundwater flows and groundwater surface water interactions globally, using a high resolution coupled groundwater and surface water model, and study the impacts of groundwater pumping from the recent past until the far future. In this talk I will present recent findings on current and projected impacts of groundwater pumping on river flows, including an estimate where and when environmentally critical thresholds for groundwater discharge are reached. Second, I will present novel developments and future research steps me and my team will take towards estimating global groundwater availability that can be sustainably exploited and the trade-off between sustainable groundwater use and crop production.
Early diagenetic transformations, fluxes, and reaction rates in Holocene sediments of the NE Greenland shelf
Authors: López-Quirós Adrián , Pearce Christof , Dorador Javier , Nieto Fernando , Rodríguez-Tovar Francisco J. , Detlef Henrieka , Elnegaard Hansen Katrine , Davies Joanna , Seidenkrantz Marit-Solveig
Published: February 2023

Process-based, mechanistic research of mineral authigenesis has been progressively utilized to understand the biogeochemical processes taking place at the sediment–water interface (SWI), and to capture long-term sedimentary (biogeochemical) records of paleoenvironments. A better understanding of mineral authigenic sedimentary processes directly beneath the SWI in Arctic continental shelves is thus fundamental as Earth’s polar regions are at greatest risk of future climate change. This is in part due to disturbances in the benthic–pelagic coupling related to changes in ocean circulation and sea ice dynamics.In this study, we aim at focusing on the Holocene period by investigating sedimentary archives recovered from the NE Greenland shelf during the NorthGreen17 Expedition. Here we combined a suite of sedimentological (e.g., detailed ichnological analysis and taphonomic features of the benthic foraminifera Cassidulina neoteretis), mineralogical (bulk and clay mineralogy) and geochemical (major, trace and rare earth elements, and δ13C and δ18O stable isotope signatures recorded in Cassidulina neoteretis) proxies with bulk organic matter parameters (δ13C, TOC, TN). The first results of this study, presented during the EGU General Assembly 2023 in Vienna, Austria, focus on several important points such as: (1) changes in sedimentation (geochemical characteristics) over the NE Greenland sediment profiles; (2) evolutionary characteristics of terrigenous influx, redox conditions and productivity; and (3) controlling factors and modes of organic matter accumulation.
Tracing Ocean circulation at the AR7W and OVIDE lines using artificial radionuclides
Authors: Leist Lisa Gerlinde Thekla , Castrillejo Maxi , Smith John N. , Christl Marcus , Casacuberta Núria
Published: February 2023

The Subpolar North Atlantic (SPNA) and Labrador Sea are key regions for deep and intermediate water mass formation and contribute to the southward return flow of the lower limb of the Atlantic Meridional Overturning Circulation (AMOC).The origin and circulation pathways of these water masses can now be studied using the artificial radionuclides 129I and 236U. These tracers are mainly released to the Nordic seas by the European nuclear reprocessing plants of La Hague and Sellafield since the 1960s. This point like source provides a unique fingerprint for Atlantic waters entering the Arctic Ocean and recirculation to the western SPNA.Here we will present results of the distribution of 129I and 236U in the Labrador Sea (AR7W Line) and the SPNA (OVIDE Line). The 129I concentrations and its temporal evolution is studied at 11 stations on a time series that started in 2014. In addition, first results of 236U  will also be  presented along the AR7W line.At the timeseries the 129I concentration shows a general increase with time and from east to west, reaching its highest concentration in the deep overflow waters and along the Eastern and Western Greenland current.The combination of the well-known tracer 129I with 236U allows to study the origin and mixing of different water masses in the SPNA.
A hybrid approach for declustering of earthquake catalogs
Authors: Köhler Jonas , Li Wei , Faber Johannes , Rümpker Georg , Stöcker Horst , Srivastava Nishtha
Published: February 2023

Usually, the earthquake catalog for a given region represents a collection of all detected and localized earthquakes and, thus, contains not only the main shocks, but also fore- and aftershocks. In order to perform an independent seismic event and seismic hazard analysis we require a catalog that, ideally, contains only mainshocks. Thus, the removal of dependent fore- and aftershocks from an earthquake catalogby declustering is a crucial step in seismic hazard analysis. Machine learning methods can potentially offer improvements in speed and accuracy in comparison to classical declustering approaches.Here, we propose a hybrid approach to identify the temporal clusters of earthquakes from the catalogs of California (USGS) and Japan (ISC). We combine unsupervised 1-D clustering algorithms with seismologically informed methods and machine learning techniques. We use epidemic type aftershock sequence (ETAS) generated catalogs as well as classically declustered catalogs to benchmark the method.
Identification of ventilated and submarine glacial meltwaters in the Amundsen Sea, Antarctica, using noble gases
Authors: Shin DongYoub , Hahm Doshik , Kim Tae-Wan , Rhee Tae Siek , Lee SangHoon , Park Keyhong , Park Jisoo , Kwon Young Shin , Kim Mi Seon , Lee Tongsup
Published: February 2023

To estimate the glacial meltwater distribution, we used five noble gases as tracers for optimum multiparameter analysis (OMPA) of the water masses in the Amundsen Sea, Antarctic. The increased number of tracers allowed us to define additional source waters at the surface, which have not been possible with a limited number of tracers. The highest fraction of submarine meltwater (SMW, ~0.6%) was present at the depth of 400 -- 500 m near the Dotson Ice Shelf. The SMW appeared to travel along an isopycnal layer to the continental shelf break >300 km away from the ice shelf. Ventilated SMW (VMW) and surface melts (up to 1.5%) were present in the surface layer <100 m. The distribution of SMW indicates that upwelled SMW, known as an important carrier of iron to the upper layer, amounts for 29% of the SMW in the Dotson Trough. The distinction between SMW and VMW made it possible to clearly distinguish the locally-produced SMW since the previous Winter Water formation from the fresh water (VMW) originated from the upstream; the production rate of the former was estimated as 53-94 G ton yr-1. The Meteoric Water fractions, consisted of SMW and VMW, comprised 24% of those derived from oxygen isotopes. This indicates that the annual input from basal melting is far less than the inventory of meteoric water derived from oxygen istopes.
Microbial communities associated with plastic mulch debris in agricultural soils
Authors: Macan Giovana P. F. , Anguita-Maeso Manuel , Landa Blanca B.
Published: February 2023

Currently, plastic mulch debris represent one of the main sources of microplastic pollution in agricultural soils. However, there is still limited research on plastic and microorganisms' interaction in terrestrial agroecosystems as compared to marine ecosystems. In this study, we have characterized the microbial communities associated with agricultural plastic mulch debris by using culture-dependent, and culture-independent (i.e., high-throughput DNA sequencing) approaches. Weathered plastic mulch debris samples were collected from the topsoil of five agricultural fields in Baza, Granada province in southern Spain, characterized by intensive horticultural production over the last ten years. The bacterial communities from the plastisphere soil (soil tightly adhered to the plastic) as well as the community tightly attached to the plastic surface were assessed by estimating the culturable populations by dilution plating on general media and the total (culturable and non-culturable) populations by NGS analysis of 16S rRNA amplicons. Additionally, all the plastic samples were characterized by FTIR spectroscopy and identified as polyethylene. The results from the culturable approach showed a significantly higher number of colony-forming units in the plastisphere soil than on the plastic surface, revealing some differences among field plots. Furthermore, 16S rRNA amplicon sequencing showed that the bacterial alpha-diversity, as measured by Richness index was higher in the plastisphere soil. Beta diversity Weighted-UniFrac index indicated that the main significant differences in the bacterial communities occurred among field plots, which might be related to the soil type, and/or crop history, and a lower effect of the plastic niche sampled. Some genera such as Arthrobacter, Bacillus, Blastococcus, Kocuria, Nocardioides, Sphingomonas, and Streptomyces were present in high abundance on both plastisphere soil and plastic surface from all the assessed fields. Furthermore, in one of the fields, the genera Polycyclovorans and Bdellovibrio showed significantly higher abundance in the plastic surface than in the plastisphere soil, indicating in this case a selective effect of the plastic for specific bacterial genera. Further research is still needed to better understand the potential impacts of plastic pollution on terrestrial agroecosystems as well as the complex interaction between plastic and microorganisms.“This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 955334 - SOPLAS.”
µASC observations of Jovian energetic electrons interaction with Europa moon
Authors: Herceg Matija , Jørgensen John L. , Denver Troelz , Sushkova Julia , Jørgensen Peter S. , Connerney John E. P. , Bolton Scott J.
Published: February 2023

Since Juno’s orbit insertion, the attitude reference for the MAG investigation onboard Juno, the micro Advanced Stellar Compass (µASC), and as a part of its additional functionality, continuously measures high energy electron fluxes in Jupiter’s magnetosphere. The µASC camera head unit (CHU) sensitivity to electrons with kinetic energy greater than 15 MeV and protons with energies >80MeV, provides a means of in-situ mapping of electron fluxes sampled during 47 Juno orbits.The focus of this study are events observed when Juno is traversing M-shell of the Galilean moon, Europa, which shows distinctly different signature from that the other moons.We present µASC observations of energetic electrons interaction with Europa moon. Europa generates a wake, that affect the high energy electron driftshell, by scattering electrons into the loss-cone. The wake is then dissolved and these interactions are observed around 20° down tail. On the upstream side, the energetic drift shell is free from hard radiation as Europa acts as an obstacle for the energetic electrons. This assymetry result in a lower electon density on the upstream side resulting in an E-field filling in the e- population from surrounding driftshells in less than 10°.
Improving drain flow simulations in a national hydrologic model with machine learning estimates of drain fraction
Authors: Schneider Raphael , Noordujin Saskia , Mahmood Hafsa , Stisen Simon , Højberg Anker Lajer
Published: February 2023

Agricultural areas are often artificially drained, especially in temperate and flat landscapes. This also applies to Denmark, where approximately half of the agricultural area is artificially drained, mostly with tile drains. The generated drain flow has significant impacts on various aspects of the hydrologic cycle such as groundwater recharge, flow paths and transport times. Consequently, drain flow is a major control on the transport of nutrients such as nitrogen. Yet, detailed knowledge of spatial and temporal variability of drain flow is inadequate due to insufficient observations of drain flow, lacking knowledge of drain infrastructure and issues of scale and hydrogeologic heterogeneity.The objective was to improve the simulation of both the spatial and temporal variability of drain flow in a large-scale hydrological model used to map nitrate transport. This model is a physically-based, distributed groundwater-surface water model of all of Denmark. It is a major challenge to simulate drain flow distribution in space and time with the national model due to its coarse horizontal resolution (500m or 100m), and the lack of drain flow observations at relevant scale. Hence, to achieve the objective, we gathered existing field-scale drain flow observations from all over Denmark. For these drain catchments, fine-scale (10m) physically based hydrological models were setup and calibrated against the drain flow observations. After successful calibration, the resulting simulated distributions of drain fraction (drain flow relative to precipitation) were regionalized to applicable areas across all of Denmark. The regionalization was performed using decision tree machine learning algorithms, and a set of topographic and geologic covariates available nationally at fine resolution. An analysis of spatial transferability of the machine learning algorithm allowed to limit predictions to applicable areas. Finally, these estimates of drain fraction are used in the calibration of the large-scale national hydrologic model, amongst other objective functions such as streamflow and groundwater heads.
Linking heat and matter turnover over microbial successional stages in the soil to substrate quality and quantity
Authors: Dehghani Mohammad Abadi Fatemeh , Reitz Thomas , Schlüter Steffen , Blagodatskaya Evgenia
Published: February 2023

One of the major research foci of modern environmental sciences is the mechanism of carbon sequestration in the course of microbial decomposition of organic compounds in soil. Microorganisms decompose soil organic matter as a source of carbon, energy, and nutrients for their metabolism. The transformation process of various organic compounds in the soil is driven by competition between diverse microorganisms during several successional stages. The number, duration, and amplitude of which are dependent on substrate quality and quantity by regulating the tradeoff between fast but less efficient and slow but more efficient microbial taxa. In the frame of the Priority Program “Soil Systems”, funded by the German Research Foundation (DFG), we aim to study the relationships between substrate turnover rate, CO2 release, heat production, and efficiency of microbial metabolism at various stages of microbial succession in the course of cellulose decomposition in a fertilized Haplic Cambisol soil. To link metabolism efficiency with microbial functional traits, the kinetic parameter of microbial enzymes and growth parameters are determined at different stages of microbial succession. This research will thus contribute to the elucidation of regulatory mechanisms of energy and matter turnover in soil.
Spatial-temporal characteristics of water storage in Africa based on GRACE and GLDAS data
Authors: Cheng Jianmei , Ding Kuiyuan , Luo Yiming , Yu Ying , Lin Yihang , He Long , Zhao Xiaowei , Zheng Kun , Wang Yanxin
Published: February 2023

United Nations Educational, Scientific and Cultural Organization (UNESCO) pointed out that about 300 million Africans live in poverty because of water scarcity. However, Africa does not lack natural water resources, but only makes insufficient use of them. We aim to understand the distribution of water storage in Africa and its changes for better management of these water resources. Based on the data from the GRACE gravity satellite and the GLDAS hydrological model, the changes in the total water storage (TWS), the surface water storage (SWS), and the groundwater storage (GWS) of Africa are calculated. On the hydrogeological base service platform OneGroundwater, we comprehensively analyzed the effects of rainfall, land use types, and other human activities on the water reserves. We found that the SWS decreases in the recent 15 years, which suggests that the utilization of surface water in Africa is significant. Meanwhile, the increase in the GWS indicates that the development of groundwater is not enough. Promoting the sustainable extraction of groundwater is helpful to the social development in Arica. Our analysis results show that rainfall is decisive for the changes in the GWS of Africa. The seasonal variation trend of the GWS is consistent with that of rainfall, while there is a certain lag in the yearly variations. The effects of land use types are mainly reflected in recharge and evaporation. The increase in vegetation density strengthens transpiration and reduces the recharge rate of groundwater.
Web-based fieldwork education system for students
Authors: Choi Yoon Jung , Lee Eunsu , Kim Jeong Chan
Published: February 2023

The spread of COVID-19 has cancelled and postponed many geoscience exercise and fieldwork activities worldwide. Various virtual fieldtrips and online courses were offered to the students to overcome this education gap. In this study, we combined virtual fieldwork with self-fieldwork exercise by creating a new fieldwork education system called ‘GeoExplorer’. ‘GeoExplorer’ is a fieldwork instruction webpage (platform), where students can easily access the platform with mobile phones and visit the fieldwork site without an instructor or a teacher. The platform provides detailed fieldwork description and instructs how the student should travel along the site. The system is fairly simple, as the student follow the map of the fieldwork site provided by the platform, the platform will explain the geology and geographic features of each stop points. This fieldwork education platform is created on the geoscience database platform ‘Geo Big Data Open Platform’ of Korea Institute of Geoscience and Mineral Resources (KIGAM). Therefore, the students can easily access detailed geological maps and geoscience information of Korea created by actual geologists and earth scientists of Korea. Currently, three geo-sites are offered for the students to explore (we plan to add more sites in the following years). These geo-sites are not only geologically important but also academically important since they contain the most recent geoscience research outcomes in Korea. We hope this new geoscience fieldwork education approach can encourage students to participate in geoscience fieldwork activities during and after the pandemic.
Expanding our knowledge: Garnet U-Pb dating and the Permo-Triassic rifting of the Cabo Ortegal Complex (NW Iberia)
Authors: Beranoaguirre Aratz , Gil-Ibarguchi Jose Ignacio , Millonig Leo J. , Albert Richard , Gerdes Axel
Published: February 2023

The novel technique of U-Pb dating of garnet allows us to date rocks that were previously impossible to put into a temporal context, either because of the absence of traditional geochronometers such as zircon, monazite, and rutile or because of isotopic disequilibrium, e.g. Lu-Hf or Sm-Nd. The possibility to exclusively date garnet crystals can give us important information to understand the geological evolution of a particular region.In this contribution, we present data from a garnet-quartz vein from the Cabo Ortegal complex, NW Iberian Massif. In the vein, andraditic garnet is associated with chlorite and serpentine in fissures, which cut the foliation of the surrounding lithologies. Field evidence thus indicates that vein formation postdates the formation of the regional foliation (ca. 390 Ma). However, until now, it is unknown, if vein formation is related to thrusting and fluid circulation during the uplift of the area (350-330 Ma) or as the consequence of igneous intrusions (ca. 300 Ma). Vein garnet was analysed in two analytical sessions. The analyses yielded unanchored lower intercept ages of 253.5 ± 7.6 Ma (MSWD = 1.1, n = 62/64) and 252.2 ± 9.5 Ma (MSWD = 1.33, n = 40/40). Those results are much younger than the basement rocks and structures in the Cabo Ortegal complex. The obtained ages coincide with the Permo-Triassic rifting widely documented from other geological domains of the Iberian Peninsula, but has never before been recognised in the Allochthonous Complexes of NW Iberian massif. The study of these types of samples may therefore provide clues to the geological history of the Cabo Ortegal Complex, which may not be available from other techniques and lithologies.
Comet dust tail detection by the Juno spacecraft’s magnetometer investigation
Authors: Jørgensen Peter S. , Jørgensen John L. , Connerney John E. P. , Toldbo Christina A. , Benn Mathias , Andersen Anja C. , Denver Troelz , Bolton Scott J.
Published: February 2023

During transit from Earth to Jupiter, NASAs Juno spacecraft carried out scientific measurements along its trajectory, using a subset of its instrument suite. One of the instruments turned on during the journey was the micro Advanced Stellar Compass, part of the MAG investigation. The fully autonomous microASC uses a camera to image the sky for attitude determination, its primary function, but it also logs objects appearing multiple times in the camera FOV that are not found in the instrument’s star catalog. In doing so, it routinely logged the motion of illuminated spallation products evolving from the impacts of interplanetary dust particles (IDPs) on the spacecraft. The system is capable of detection of IDPs with a diameter larger than ~5µm, i.e. particles in the size range responsible for the Zodiacal light. The detection mode was activated just after Juno performed a deep space manoeuver at 2.2AU setting the spacecraft up for a gravity assist from a close Earth flyby, sending Juno on a trajectory to rendezvous with Jupiter. The first leg of the journey, from 2.2AU to 0.8AU and to the Earth flyby, was in the ecliptic plane, whereas the trajectory from Earth to Jupiter rose well above the ecliptic plane. This resulted in measured IDP density profiles both in and above the ecliptic plane. In December 2015, half a year before Jupiter orbit insertion, a conspicuously high rate of dust impacts was detected for a fortnight. A closer analysis showed that Juno happened to pass through the tail of a Jupiter family comet.We here present the observations of the particle population during the December 2015 event, discuss the dust tail evolution and morphology, and present the implications for the comet’s size and volatility.
On the Nature of Ion-to-Electron Scale Field Fluctuations in the Solar Wind: Insight from Artemis Observations, Simulations and Linear Theory
Authors: Salem Chadi , Bonnell John , Chaston Christopher , Klein Kristopher , Franci Luca , Roytershteyn Vadim
Published: February 2023

Recent observational and theoretical work on solar wind turbulence and dissipation suggests that kinetic-scale fluctuations are both heating and isotropizing the solar wind during transit to 1 AU.  The nature of these fluctuations and associated heating processes are poorly understood. Whatever the dissipative process that links the fields and particles - Landau damping, cyclotron damping, stochastic heating, or energization through coherent structures - heating and acceleration of ions and electrons occurs because of electric field fluctuations. The dissipation due to the fluctuations depends intimately upon the temporal and spatial variations of those fluctuations in the plasma frame.  In order to derive that distribution in the plasma frame, one must also use magnetic field and density fluctuations, in addition to electric field fluctuations, as measured in the spacecraft frame (s/c) to help constrain the type of fluctuation and dissipation mechanisms that are at play.We present here an analysis of electromagnetic fluctuations in the solar wind from MHD scales down to electron scales based on data from the Artemis spacecraft at 1 AU. We focus on a few time intervals of pristine solar wind, covering a reasonable range of solar wind properties (temperature ratios and anisotropies; plasma beta; and solar wind speed). We analyze magnetic, electric field, and density fluctuations from the 0.01 Hz (well in the inertial range) up to 1 kHz. We compute parameters such as the electric to magnetic field ratio, the magnetic compressibility, magnetic helicity, compressibility and other relevant quantities in order to diagnose the nature of the fluctuations at those scales between the ion and electron cyclotron frequencies, extracting information on the dominant modes composing the fluctuations. We also use the linear Vlasov-Maxwell solver PLUME to determine the various relevant modes of the plasma with parameters from the observed solar wind intervals. These results are supplemented by analysis of fully nonlinear kinetic simulations of decaying turbulence at small scales. We discuss the results and highlight  the relevant modes as well as the major differences between our results in the solar wind and results in the magnetosheath.
Aquifer Thermal Energy Storage in the UK: current status and challenges to uptake
Authors: Regnier Geraldine , Firth Hayley T. , Jackson Matthew D.
Published: February 2023

Aquifer Thermal Energy Storage (ATES) has the potential to provide large scale, seasonal, low carbon heating and cooling to the built environment. Currently, heating of buildings represents 23% of the UK’s greenhouse gas emissions. ATES could therefore be a key technology for the UK to meet its net zero targets, particularly as cooling demand is set to increase in a warming climate.The potential for ATES developments in the UK is significant: it has a seasonal climate, and many major cities are underlain by suitable storage aquifers such as the Chalk beneath London, and the Permo-Triassic sandstone aquifers beneath Manchester and Liverpool. Despite this large potential, the uptake of ATES in the UK is limited, with only 11 installations over the past 16 years. 10 of these installations target the Chalk aquifer and 9 are located in London. In this study, we report the current status of ATES installations in the UK. A case study of an operational ATES system in the fractured Chalk aquifer in London is presented. Monitoring data over a 7 year period are used to quantify the performance of the system, with key metrics such as energy balance and thermal recovery being reported.We also report challenges to uptake of ATES in the UK. Poor performance due to a lack of understanding of the technology is observed. Inadequate monitoring of the systems (temperature, flowrate) as well as large imbalances between heating and cooling loads are identified as key issues with some current ATES systems in the UK. The complexity of the UK aquifers is also identified as a potential challenge, as geological heterogeneity has been shown to lower system efficiency and increase the risk of well interference. Finally, a lack of awareness of ATES technology is also identified as a key barrier to uptake, so it is not considered as an option to provide heating and cooling to buildings by key stakeholders such as local and national planners and policy makers.  We report ongoing work to overcome these challenges.
Impact of subglacial hydrology recharge location and intensity on ice dynamics.
Authors: de Fleurian Basile
Published: February 2023

As temperatures continues to increase, a larger amount of snow and ice is melting at the surface of ice sheets and glaciers. It is now clear that this increase in meltwater availability has a direct impact on ice dynamics on a seasonal timescale, and there are strong presumption that this is also the case on longer timescales. The recent evolution of subglacial hydrology models now allows them to be directly coupled to ice dynamics model to perform long term simulation of this systems and provide the link between ice dynamics and the evolution of climate. There is however still a large number of open questions to answer in order to provide long term realistic simulations of this coupled system. One of those questions is the impact of the recharge location an intensity of the subglacial hydrological system on ice dynamics, or whether the injection of water in the system needs to pass through Moulins or can be approximated as a uniform source. The impact of the recharge strategy on subglacial hydrology model alone has yielded contrasted results with a potential impact on short timescale but a limited influence once integrated over a full season. Here we want to investigate the direct effect of this recharge scenarios on the ice dynamics itself.We apply the Ice-sheet and Sea-level System Model (ISSM) to a synthetic glacier with a geometry similar to a Greenland ice sheet land terminating glacier. Using a range of moulin density (or uniform input) for the recharge of the subglacial hydrology model we observe the response of the ice dynamics itself both on short and longer timescales. Those simulations provide an insight into the importance of recharge location and intensity of the subglacial drainage system directly on the ice dynamics, and so provide a baseline for the choice of recharge style for more realistic simulations.
Methane Emission from lakes on continuous and isolate permafrost in Russia
Authors: Fedorova Irina , Shornikova Anna , Chulkova Ekaterina , Arestova Irina
Published: February 2023

Greenhouse gases emission from lakes is quite significant environment question in the cryosphere. Up to know the volume of storage and reason that influence on it are underestimated. If GHG emission for the Arctic landscapes and boreal wetlands are measuring on seldom stations, data from permafrost border is insufficient.There are continuous and isolated permafrost with many lakes in Russia. Emission from the surface of thermokarst and periglacial lakes were measured in Yamal peninsula and Tunkinskaya valley (the Russian Arctic and Baikal region) in summer 2022. Both regions have natural and anthropogenic changed aquatic ecosystems. Several geochemical, ecological and hydrodynamical features of lakes were consider as well.CH4 emission from thermokarst lake near Salekhard city was 237 mgCH4·m-2·day-1 in site of volume for thermokarst lake Shorshonka in Tunkinskaya valley was more than 2000 mgCH4·m-2·day-1 (the air temperature was equal). Eutrophic lake near Tunkinskiye Goltsy Mountain Ridge gave 1020 mgCH4·m-2·day-1 in summer period. Methane concentration in lake sediments was 2.1-8.3 µg/l for lakes in southern Yamal and reached 13.6 µg/l in Baikal region. Biogenic elements concentration in all lakes as usual was in the limit. Isotope content was also a little bit strange for Shorshonka lake (4.67 δ18O, ‰). Other lakes near Salekhard city and Baikal lake had amplitude 11-16 δ18O, ‰.   Therefor we can tell about strong differences for methane emission from thermokarst lakes in continuous and isolated permafrost that flux should be studied more detail.   
Spatial Variability and Composition of Ice Nucleating Particles over the Southern Ocean
Authors: Moore Kathryn , Hill Thomas , McCluskey Christina , Rainwater Bryan , Toohey Darin , Twohy Cynthia , Jensen Jorgen , Kreidenweis Sonia , DeMott Paul
Published: February 2023

Supercooled liquid clouds are ubiquitous over the Southern Ocean (SO), even down to temperatures of -25 °C, and comprise a large fraction of the marine boundary layer clouds. Many Earth System Models and reanalysis products overestimate the occurrence of ice and have insufficient liquid cloud cover in the region, while recent simulations have found that the microphysical representation of ice nucleation and growth has a large impact on these properties. However, measurements of SO ice nucleating particles (INPs) to validate simulated ice nucleation are sparse, and many previous observations were limited to fairly warm temperatures (-15 or -20 °C). Observations of INPs are presented here from two simultaneous field campaigns in the SO during January-March 2018: the Clouds, Aerosols, Precipitation Radiation and atmospherIc Composition Over the southeRN ocean II (CAPRICORN-2) study on the CSIRO R/V Investigator, and the Southern Ocean Cloud Radiation Aerosol Transport Experimental Study (SOCRATES) on the NSF/NCAR G-V aircraft. The SOCRATES campaign is noteworthy for collecting the first in-situ observations in and above cloud in the SO. Measurements of INPs active in the immersion freezing mode were made during both projects in real time with Colorado State University (CSU) Continuous Flow Diffusion Chambers (CFDCs) at temperatures below -25 ℃, and via offline analyses of aerosol filter and seawater samples using the CSU Ice Spectrometers from -10 to -30 ℃. INP concentrations were at the lower bound of those from other ocean regions, and much lower than historical measurements in the SO collected prior to the early 1970s. Chemical treatments performed on the filter suspensions were used to infer the fraction of biological, organic, and mineral INPs, which varies with latitude and height, and indicate a variety of sources, including local marine aerosol and dust. Data from G-V overflights of the R/V Investigator were used to investigate the vertical structure of INPs in this region. Electron microscopy analyses of INPs collected from the CFDCs, along with back trajectories and aerosol measurements, provide additional information on INP composition and possible sources.
Development of low-cost material for the remediation of inorganic contaminants by using PRB
Authors: Roohmoney Roohmoney , Chakma Sumedha
Published: February 2023

Groundwater is a key source of water used in many essential activities across the world, including irrigation (42%), public water supply (36%), industrial uses (24%), and power production. Furthermore, the quality of groundwater is quickly degrading owing to uncontrolled operations. Most developing countries, including India, have polluted groundwater due to an oversupply of heavy metals, fluoride, rich nutrients, and hydrocarbons. Various technologies like the Pump & Treat method were used to treat it but they are very expensive and less effective, so there is a need to develop low cost and effective technology for its treatment. A Permeable Reactive Barrier (PRB) is an effective groundwater remediation method. The key advantage is that it does not require the running of pumps or treatment vessels, saving on operation and maintenance expenses and enabling the economic worth of property to be maintained during rehabilitation. The goal of this research is to find low-cost materials that can be employed as reactive materials in a PRB to remove inorganic pollutants from groundwater and the aquifer. To that end, numerous low-cost material samples were exposed to characterization tests, batch testing, and a washing process to analyze the material's adsorption and desorption capabilities at varied doses, concentrations, and contact periods. Few of the low-cost materials functioned admirably, removing all contaminants (>98%), whereas others were deemed inappropriate for several reasons. The best-performing material is then adopted for two bench-scale column tests to imitate the PRB.
Alicante IVS Analysis Center
Authors: Karbon Maria , Belda Santiago , Azcue Infanzon Esther , Escapa Alberto , Martinez Marin Juan Antonio , Moreira Mariana , Puente Garcia Victor , Ferrandiz Jose Manuel
Published: February 2023

Very Long Baseline Interferometry (VLBI) is a highly accurate method, used since the 1970s in astrophysics as well as in geodesy. It contributes significantly to the global international terrestrial reference frame (ITRF) and is the only space geodetic technique able to realize the international celestial reference frame (ICRF) as well as to observe the full set of Earth orientation parameters (EOP: polar motion, universal time, precession / nutation). The IVS (International VLBI Service for Geodesy and Astrometry) analysis center in Alicante UAVAC (University of Alicante VLBI) was established as an associate AC in 2018 at the department of Applied Mathematics at the University of Alicante, within the research group of space geodesy and space dynamics. Further, we have a close partnership with the IGN (Instituto Geográfico Nacional) and RAEGE (Red Atlántica de Estaciones Geodinámicas y Espaciales / Rede Atlântica de Estações Geodinâmicas e Espaciais). In the first quarter of 2022 we started with the first steps to become an operational AC, with the final goal to be a full contributor to future ICRF and ITRF realizations, as well as operational products like the IVS combined EOP products. In this report we introduce the community to our group, our technical setups in terms of hard- and soft-ware, as well as our preliminary products. We present the first results based on our reanalysis of the IVS-archives (1979-12.2022) using VieVS 3.2 (one of several software we plan on using), and show the main geodetic products, i.e. EOP, CRF and TRF.  
An innovative approach to discern variation in long-term regional monsoonal rainfall trend in North Eastern India.
Authors: Chakra Swagatika , Oza Harsh , Ganguly Akash , Padhya Virendra , Pendey Amit , Deshpande Rajendra Dattatray
Published: February 2023

The global hydrological cycle is changing in response to climate change and anthropogenic influence. The rainfall, on an annual or sub-decadal timescale, has exhibited erratic and substantial deviation from the long-term average in different parts of the world. Consequently, there are epochs of higher or lower than average rainfall but these are missed in long-term monotonic trend.As commonly experienced, the rainfall within different geographical regions also varies significantly in terms of magnitude and timing, and on a smaller spatial scale. Integrating large geographical areas and long timescales for monotonic rainfall trend analyses for the meteorologically homogenous regions provides a general picture which is useful for the purpose of administration, water management and distribution. However, it cannot discern the decadal to multi-decadal rainfall variation in different parts of a meteorologically homogenous region and hence a more advanced and comprehensive approach is required for advancing scientific understanding about the hydrometeorological processes and factors governing multi-decadal rainfall variation.In this study, an innovative approach is presented which involves: (1) 31 years moving average of percentage departure of seasonal rainfall for 120 years at district level; (2) 15 year sliding slope analyses to identify the year of inflection point based on change in direction of slope; (3) K-Means cluster analyses; (4) normality test of clusters based on Z score; and determination of timeframe during which rainfall trend changed significantly.This approach was tested in the North East India where the rainfall is derived by one of the most dynamic and complicated meteorological systems. Improving understanding about rainfall variability in Northeast India is also very important from ecological, environmental and strategic point of views. Using the above approach, long-term rainfall data (1901-2020) has been analyzed at a district level in Northeast India. Using K means clustering method time windows of prominent change in rainfall trend have been identified. It is inferred from this study that Northeast India has experienced three major climatological events, during 1929-1941, 1961-1971, and 1984-1992. The first and the third events involving a trend reversal from increasing to decreasing nature around 1929-1941 and 1984-1992 affected respectively 49% and 43% area of Northeast India. The second event involving a trend reversal from decreasing to an increasing trend around 1961-1971 impacted 38% of northeastern India.The meteorological processes corresponding to these timeframes, which could have caused these major rainfall trend reversals are being examined.
Attempt to nowcast the latitudinal position of the SAPS structure using the SuperDARN Hokkaido Pair of radars
Authors: Nishitani Nozomu , Hori Tomoaki
Published: February 2023

The Sub-Auroral Polarization Streams (SAPS) are one of the most outstanding phenomena in the subauroral ionosphere. Its position can be a measure for nowcasting the intensity/size of the global ionospheric convection. In the current study, the latitudinal distribution of SAPS is discussed based on the over ten years of observation achieved by the SuperDARN Hokkaido Pair of radars, which are located at the lowest geomagnetic latitudes among the SuperDARN radars. Previous statistical studies showed that the latitudinal position of the SAPS structure could be predicted on average as a function of magnetic local time and the Dst geomagnetic index. The multi-event study shows, however, that the latitude of the SAPS structure does not always follow the empirical relationship, which could determine the latitude of the SAPS structure as a function of the Dst index and magnetic local time. For example, a detailed analysis of the 8 Sep 2017 event indicates that the SAPS position is located at a significantly lower geomagnetic latitude than the statistically expected position, even if the magnetic local time and Dst geomagnetic activity effects are considered. Possible reasons for such an unusual position, including the history of the IMF and the solar wind parameters and occurrence of substorms, are investigated.
Mesoscale Gradients in Soil Moisture over South America Lead to Enhanced Convection
Authors: Dominguez Francina , Chug Divyansh , Taylor Christopher , Klein Cornelia , Nesbitt Stephen
Published: February 2023

This work presents the first observationally-based study over subtropical South America linking the spatial location of convection and drier soil patches of the order of tens of kilometers, as well as observational evidence of the control of background flow on the sign of SM-PPT feedbacks at convective scales. Using satellite data from multiple infrared and microwave radiometers, we track nascent, daytime convective clouds over subtropical South America and quantify the underlying, antecedent (morning), SM heterogeneity. We find that convection initiates preferentially on the dry side of strong dry-wet SM boundaries that are associated with spatially drier and warmer patches of tens of kilometers scale consistent with findings in other parts of the world. This preference maximizes during weak background low-level wind, high convective available potential energy, low convective inhibition and low vegetation density when analyzing surface gradients of 30 km length scale. On the other hand, surface gradients of 100 km length scale are significantly associated with afternoon convection during convectively unfavorable synoptic conditions and strong background flow, unlike previous studies. The location of the precipitation maxima following CI onset is most sensitive to the lower tropospheric background flow at the time of CI. The wind profile during weak background flow does not support propagation of convective features away from the dry regions and rainfall accumulates over the dry patch. Convection during strong background flow leads to greater rainfall hundreds of kilometers away from the CI location.   
Regression-based regionalisation of hydrological parameters using catchment’s spectral signature
Authors: Fragoso-Campón Laura , Durán-Barroso Pablo , Quirós Elia
Published: February 2023

Water resources management is difficult due to the uncertainties of the parameters controlling the hydrological response and, this uncertainty is even greater in ungauged basins where parameters are generally defined by regionalisation approaches. Among the available methods, one of the most used is the regression-based approach, which relates the most appropriate parameter values to catchment properties, such as physical properties, topographic, land use, soil and geological data. This approach assumes that the hydrological response depends on the catchment attributes and the hydrological response in catchments with similar characteristics is meant to be similar, and traditionally, these properties are derived from cartographic data sources. Since the spectral response of the territory depends on these attributes, this study uses remote sensing techniques to characterise the spectral response and apply it to the regionalisation of hydrological parameters using a machine learning approach with Random Forest.The study area is a Mediterranean environment in Spain and corresponds to eighteen gauged watersheds in the region of Extremadura, in which we find two bioclimatic variants: a wetter and a drier one. In this study the algorithm is tested in two scenarios for regionalisation, the new approach using the spectral signature of the catchments and the results are compared with the traditional approach using the physical properties from data provided by the European Soil Data Centre. The spectral response of the catchments is studied using images from the Sentinel-1 (S1) and Sentinel-2 (S2) missions of the Copernicus Program of the European Commission. S1 is a synthetic aperture radar (SAR) sensor (C-band ) and S2 is a multispectral sensor working in the visible, near-infrared and shortwave infrared bands. In addition, several spectral indices and texture metrics derived from the grey-level cooccurrence matrix are also used for a better characterization of the watersheds.The results perform well in both scenarios showing almost the same goodness of fit and the efficiency depends on the climatic environment. In this sense, the prediction in the wetter catchments exhibits better performance than the driest variant.  Specifically in the latter, the spectral regionalisation outperformed the physical scenario. The new spectral approach shows promising results, especially considering the advantage of having continuous coverage of Sentinel data worldwide, which offers new possibilities in areas where no mapping information is available.