bluuebunny/crossref_metadata_2025 huggingface dataset:
Atmospheric contributions to the reversal of surface temperature anomalies between early and late winter over Eurasia
Authors: Xu Xinping
Published: February 2023

Observations have shown sub-seasonal reversal of temperature anomalies between early and late winter over Eurasia, which is distinct from the seasonal mean condition. Based on the reanalysis data, the 1800-year control simulation and the 40-member ensemble simulations in 1920–2100 from the Community Earth System Model (CESM) Large Ensemble (CESM-LE), this study reveals that the reversal of surface air temperature (SAT) anomalies between early and late winter is one of the dominant and intrinsic features of the Arctic-Eurasian winter climate. Such a reversal is characterized by “colder Arctic, warmer Eurasia” in December (January–February) and ‘warmer Arctic, colder Eurasia’ in January–February (December). Robust climate dynamic processes associated with the reversal of SAT anomalies, including sub-seasonal reversals of anomalies in the Ural blocking, mid-latitude westerlies and stratospheric polar vortex, are found in both reanalysis data and CESM simulations, indicating the important role of internal atmospheric variability. Further analysis reveals that the reversal of Ural blocking anomalies in late December can be a potential precursor for the reversal of SAT anomalies in late winter. The reversal of mid-latitude westerly wind anomalies associated with the Ural blocking can affect upward propagation of planetary-scale waves especially with wavenumber 1, subsequently promoting the contribution of stratospheric polar vortex to the reversal of SAT anomalies in late winter over the Arctic-Eurasian regions. Such a troposphere-stratosphere pathway triggered by the perturbation of tropospheric circulations is confirmed by the CESM-LE simulations, and it may be useful for the prediction of sub-seasonal reversal of SAT anomalies.
The Plastic Underground: Are Microplastics in the Subsurface a Ticking Time Bomb for Soil and Groundwater Ecosystems?
Authors: Krause Stefan , Schneidewind Uwe , Wazne Mohammad , Kukkola Anna , Lynch Iseult , Haverson Lee , Kelleher Liam , Davies Grace , Dendievel Andre-Marie , Mourier Brice , Mermillod-Blondin Florian , Quiñones-Rivera Zoraida , Simon Laurent , Reiss Julia , Perkins Dan , Robertson Anne , Gomez-Velez Jesus
Published: February 2023

Increasing volumes of mismanaged plastic waste have resulted in millions of tons of plastics entering the environment. While recent research has made substantial progress in determining the fate and transport of microplastics (MP) in river systems and their subsequent discharge to the worlds oceans, much less is known about the subsurface fate of MP as they enter soils, (riverine) sediments and global groundwater resources. Initial studies have identified MP in selected groundwater samples and there is great interest to understand entry pathyways of MPs into soils, in particular through agricultural pathways. The mechanisms of MP release from agricultural sources such as seed and agrochemical encapsulations or sewage sludges as well as the total quantity, spatial distribution, residence time scales as well as the impact of MP on soils and subsequently groundwater ecosystems are completely unknown. There is hence a critical need to study the role of soils and groundwater systems as a long-term sink for plastic pollution, including the development of legacy risks.Here we identify the significance of various entry pathways for MP into subsurface ecosystems, integrating experimental and model based quantifications of MP transport through streambed sediments with quantifications of MP inputs into agricultural soils through irrigation with river water. We present first results of MP impacts on the functioning of subsurface ecosystem services, by the particular example of MP exposure impacts on the behaviour of bioturbating invertebrates and the subsequent consequences for sediment biogeochemical cycling in order to draw attention to the potential risks for vital soil and groundwater ecosystem services.We complement this site specific mechanistic process understanding with global estimates of mismanaged plastic waste accumulation in river basins to quantify MP catchment wide loads available for leakage into soils and present first results of our recently started participatory approach that aims to develop a baseline of MP pollution in aquifers across the world. Such baseline data is imperative to increase our understanding of MP fate and transport processes, MP uptake by groundwater organisms and the interaction of MP with nutrients and potential co-contaminants. Our specifically tailored protocol allows for standardized MP sampling in boreholes, springs or wells across a wide range of geological settings and land cover classes. We invite and encourage the community to contribute to this global effort in order to enable estimates of the magnitude and expected time scales of soil and groundwater MP contamination.
On the Correlation between the sodium in the MLT and meteor radiant distribution
Authors: Li Yanlin , Huang Tai-Yin , Urbina Julio , Vargas Fabio , Feng Wuhu
Published: February 2023

The sodium layer in the mesosphere and lower thermosphere (MLT) region is originated from meteoroid mass deposits produced by its ablation. Understanding the correlation between the meteoroid material input and the concentration of the sodium layer is essential for many investigations that use sodium as a tracer to study the dynamics in the MLT. A new numerical sodium chemistry model has been developed to study such correlation, and the results are cross-compared to the meteoroid material input inferred from the recently revealed sporadic meteor radiant distribution derived from the data gathered by the Arecibo Observatory. The sodium chemistry model is computationally efficient, runs in high-time resolution, and the sodium-bearing species are equally treated in the continuity equation devoid of making any steady-state approximation. This work will also present the seasonal and latitudinal distribution of meteoroid injection rates derived from the aforementioned sporadic meteor radiant distribution.Our simulation results agreed with the general feature of the measurements obtained from the Colorado State University Lidar (CSU) and the Andes Lidar Observatory (ALO) but with variations three times smaller.
Forecasting the monthly severity of widespread flooding in Germany using dilated convolutional neural networks conditioned by large-scale climatic indexes
Authors: Tarasova Larisa , Ahrens Bodo , Hoff Amelie , Lall Upmanu
Published: February 2023

Spatially co-occurring floods pose a great threat to the resilience and the recovery potential of the communities. A timely forecasting of such events plays a crucial role for increasing the preparedness of public and private sectors and for limiting the associated losses. In this study we investigated the potential of dilated Convolutional Neural Networks (CNN) conditioned on a set of large-scale climatic indexes and antecedent precipitation for monthly forecast of widespread flooding severity in Germany using 63 years of streamflow observations. The severity of widespread flooding (i.e., spatially co-occurring floods) was estimated as simultaneous (within a given month) exceedance of an at-site two-year return period for streamflow peaks across 172 mesoscale catchments. The model was trained for the whole country and for the three diverse hydroclimatic regions individually to provide insights on spatial heterogeneity of model performance and drivers of flooding. Evaluation of the model skill for floods generated by different processes revealed the largest bias for events generated during dry conditions. The bias for rain-on-snow flood events was the lowest despite their higher severity indicating higher predictability of these events from large scale climatic indexes. Model-based feature attribution and independent wavelet coherence analyses both indicated considerable difference in the major drivers of widespread flooding in different regions. While the flooding in the North-Eastern region is strongly affected by the Baltic Sea (e.g., East Atlantic pattern), the North-Western region is affected more by global patterns associated with the El-Niño activity (e.g., Pacific North American pattern). In the Southern region in addition to the effect of the global patterns we also detect the effect of the Mediterranean Sea (Mediterranean Oscillation Index), while antecedent precipitation seems to play less important role in this region compared to the rest of the country. Our results indicate a considerable potential for forecasting widespread flood severity using dilated CNN especially as the length of the available time series for training increases.
Time-Lapse Volumetric Seismic Imaging of Water Masses at a Major Oceanic Confluence in the South Atlantic Ocean
Authors: Chen Xiaoqing , White Nicky , Woods Andy
Published: February 2023

Water-mass interaction processes within the Southern Ocean strongly influence the global oceanic circulation system.  For example, the western side of the South Atlantic Ocean is dominated by the confluence between the Brazil Current (BC) and Falkland/Malvinas Current (MC). At this confluence, tropical/subtropical (i.e. warm and salty) waters are transported southward by the BC where they interact with subantarctic (i.e. cold and fresh) waters transported northward by the MC. This interaction creates a highly dynamic frontal system that is characterized by complex water mass interactions and intense diapycnal mixing. Here, we exploit time-lapse volumetric seismic imaging of the Brazil-Malvinas Confluence (BMC) in order to elucidate the detailed thermohaline structure of this critical region. Careful signal processing of a ~25 terabyte survey, acquired during February 2013, reveals a spectacular northeastward dipping oceanic front that extends as deep as ~1800 m. Significantly, a deep transient mesoscale eddy is embedded in this front. This eddy appears to grow and decay over ~11 day period and it has a maximum diameter of ~40 km. Time-lapsed imagery also reveals mesoscale to sub-mesoscale complexity at all depths. Long wavelength temperature fields extracted from our acoustic velocity measurements reveal a pattern of cool anomalies on the MC side together with a steep and fanning temperature gradient close to the front but above the eddy, indicative of heat transfer. Evolution of this prominent eddy embedded in the front can be independently investigated using velocity fields calculated from the GLORYS12v1 product for the period of interest. Tracked particles, which are released daily through the confluence area down to 1800 m, flow along the MC from 40° S  to 36° S and are deflected clockwise by the BMC. This flow suggests that the observed eddy is cyclonic and related to MC recirculation, as a result of the combination of the steep continental slope and geometry of the BMC. In this way, cooler water masses are juxtaposed against the front. A simple one-dimensional steady-state model is used to examine heat transfer across the front. Our results highlight the importance of combining high quality three-dimensional seismic imagery with hydrographic observations in order to elucidate the fluid dynamics of complex oceanic fronts.
The influence of environment on adaptive radiation of diatoms in East African Rift lakes
Authors: Jovanovska Elena , Stone Jeffery , Salzburger Walter , Schrenk Friedemann
Published: February 2023

Adaptive radiation is considered to play an important role in the diversification of life on Earth. This is especially true in isolated long-term environments where the largest adaptive radiations have been found and where the adaptive nature of diversification has been best studied. However, the environmental conditions that influence rapid diversification during adaptive radiations and potentially lead to differences in evolutionary trajectories and species richness across the tree of life are still unclear, primarily because there few, if any, fossil records for some of the most iconic examples of vertebrate radiations. Here, we use two diverse groups of diatoms (Diploneis and Afrocymbella) with different lifestyles and great fossilization potential to test the role of environment in adaptive radiation and its impact on evolutionary trajectories between different diatom clades in East African Rift lakes that are home to the world's largest radiations – that of cichlid fishes. We constructed a time-calibrated molecular phylogeny of extant and extinct species, as well as a trait matrix, and show that the two diatom groups evolved within the rift from a common ancestor over a relatively short time, with accelerated diversification leading to much higher species richness in the genus Diploneis. We then correlate the inferred diversification rates and trajectories of trait evolution with biological and environmental variables to determine the influence of the environment on the progression of adaptive radiation. This integration of genetic, morphological, and paleoenvironmental information allowed us to demonstrate the influence of the environment on a key process that has produced much of Earth's biological diversity.
Coronal Mass Ejection driven sheath regions and proton acceleration
Authors: Kilpua Emilia ,   Emilia Kilpua
Published: February 2023

Coronal Mass Ejections (CMEs) are large-scale eruptions from the Sun that drive shocks and turbulent sheaths ahead of them. Parker Solar Probe, Solar Orbiter and BepiColombo have recently observed several shocks/sheaths closer to the Sun than the Earth’s orbit. These studies have revealed enhanced energetic proton fluxes from in-situ observations in interplanetary space also in the sheaths preceding slow CMEs. In this presentation we discuss the internal small-scales sheath structures (e.g., mini flux ropes) and embedded magnetic fluctuations as well as related energization mechanisms. The results suggest that the CME-driven sheaths can have an important role in the acceleration of energetic particles.
Urban geotourism in the historic center of Las Palmas de Gran Canaria (Canary Islands, Spain)
Authors: Leal Moreno Victoria Josefina , Dóniz-Páez Javier , Di Nardo Daniel , Albertos Violeta Tai , Pérez Nemesio M. , Hernández Pedro A. , García-Romero Leví , Marrero-Rodríguez Néstor
Published: February 2023

Urban geoturism is a relatively recent type of tourism that has increased a lot in recent years. The elaboration of geotouristic trails is the main way to develop this type of tourism in cities. Urban geotourism aims at exploiting the cultural heritage (churches, hermitages, cemeteries, houses, squares, streets, etc.) and the urban layout itself. But too the geographical and natural elements (volcanoes, ravines, cliffs, beaches, dunes, etc.) that have not been wiped out by the urban growth and transformation processes. In this study we have chosen the old centre of las Palmas de Gran Canaria (LPGC) in Gran Canaria. The Canary Islands are an active volcanic region located in the Eastern Atlantic Ocean, about 100 km off the west coast of Africa and at a subtropical latitude. The choice of the city of LPGC is due to the fact that it is the main city of the Canary Islands (378.675 inhabitants) and has one of the oldest, largest and best preserved centers in the Canary Island. The aim of this work is to propose an urban geotourism itinerary through the historical centre of Vegueta and Triana neighbourhoods in LPGC city (Gran Canaria, Canary Islands, Spain). The methodology will consist of identifying, selecting and characterizing different geomorphosites in the city (cliffs, beaches, fossil dunes) and describing the main types of stone used for the construction and ornamentation of buildings from the foundation of the city in the 15th century to the present day. Based on the variety of resources identified and inventoried, we have proposed a geographical urban geotourism itinerary to satisfy and diversify the tourist offer of the city, which consists of 24 points distributed between the historic neighborhoods of Triana and Vegueta, in which elements of the volcanic heritage of the island and/or that present important natural and cultural value linked mainly to religious (10) and civil (15) heritage. This proposed route is of low difficulty and can be done in two hours. The material identified mainly in elements of the facades of the buildings is gray, white, and green ignimbrite and scoria volcanic rocks. Part of this material comes from the Tirma, Teror and Galdar quarries. Elements of sandstone, limestone, pumice, organogenic sand, boulders, red scoria were also identified, as well as structures with the presence of sandstone as cement. (Volturmac-MAC2/4.6c/298).
Impact of convection on trace gas composition during the summer monsoon season downwind of East Asia and over central North America
Authors: Atlas Elliot , Smith Kate , Treadaway Victoria , Schauffler Sue , Hendershot Roger , Lueb Richard , Donnelly Stephen , Pope Leslie , Pan Laura , Thornberry Troy , Newman Paul , Bowman Ken ,   ACCLIP and DCOTSS Science Teams
Published: February 2023

Airborne research missions were conducted during the summer season over the Western Pacific downwind of the Asian summer monsoon (ACCLIP, Asian Summer Monsoon Chemical & CLimate Impact Project, Aug/Sept., 2022) and over central N. America (DCOTSS: Dynamics and Chemistry Of The Summer Stratosphere, July/Aug., 2021 and May/July, 2022).  A major objective of both of these missions was to characterize the impact of convective transport of trace gases on regional and hemispheric air quality and on ozone chemistry in the UT/LS.  The DCOTSS campaign focused on outflow from overshooting convection, and ACCLIP targeted outflow and eddy-shedding from the Asian summer monsoon anticyclone.  Whole air samples were collected from the three aircraft deployed during the missions (NSF GV, NASA WB-57, and NASA ER2), and a wide range of organic trace gases were measured that included NMHC, long and short-lived halocarbons and organic nitrates.   In-situ measurements of ozone and other trace gases were also included in the airborne instrument payloads.  Both campaigns showed cases of tropospheric transport into UT/LS region, with significantly larger amounts of certain trace gases (e.g., dichloromethane and others) found in the ACCLIP region.  This presentation will provide an overview of selected trace gas distributions and correlations from these campaigns to illustrate the role of the different monsoon regions on the chemistry of the UT/LS.
Numerical Simulation and Uncertainty Quantification of Models for Coseismic Damage and Healing of Rocks in 1D, 2D and 3D
Authors: Niu Zihua , Gabriel Alice-Agnes , Igel Heiner
Published: February 2023

The instantaneous weakening of rocks during the passage of seismic waves has first been observed in laboratory experiments. The change of elastic rock moduli during and after the dynamic perturbations typically includes three phases – a gradual drop of moduli, a dynamically steady state and the recovery over a time scale that is larger than that of the perturbations. Such changes have been referred to as slow dynamics (Johnson and Sutin, 2005). With the development of the long-term continuous monitoring of the velocity field inside the Earth using methods such as ambient noise interferometry, coseismic rock weakening and post-seismic recovery of rock strength have also been recorded in the field over the past two decades. The question that we want to answer is: how relevant is the non-classical nonlinearity observed in the lab to the coseismic velocity drop in the field? To this end, we aim to adapt an analytical model that explains the lab observations and apply it to field observations using numerical simulations. Our first step is to identify the appropriate nonlinear model(s). Most of the proposed physical models that explain the phenomenon contain many parameters and are hard to constrain. Moreover, most of the existing physical models are restricted to 1D analysis and are difficult to generalize to 2D or 3D modeling. We apply two models within the framework of the continuum damage mechanics: (i) the internal variable model (Berjamin et al., 2017) and (ii) the continuum damage model that accounts for parallel micro-cracks oriented perpendicular to the maximum tension or compression (Lyakhovsky et al., 1997). Both models can generalize to 2D and 3D. We formulate both models as nonlinear hyperbolic partial differential equations (PDEs) and solve them with the arbitrary high-order discontinuous Galerkin method using ExaHyPE (Reinarz et al., 2020) in 2D and 3D. We show that both models successfully reproduce the three phases during and after dynamic perturbations observed in the laboratory. We find that the continuum damage model can explain the amplitude- and frequency-dependent damage with a good match against the lab measurements. We also compare the simulation results using both models quantitatively with the observations in a 2D copropagating acousto-elastic testing (Feng et al., 2018). Our sensitivity analysis of the model parameters using the Markov chain Monte Carlo method quantitatively estimates the uncertainties and correlations among the parameters of both models. We believe our work paves the way towards a model of nonlinear rock deformation with slow dynamics that can be used in large scale 2D and 3D seismic wave propagation simulations for direct analysis of field observations, such as the Tohoku earthquake, 2011 (Brenguier et al., 2014).
A long-term charge/discharge cycle at Mt. Etna volcano revealed through absolute gravity and GPS measurements
Authors: Greco Filippo , Bonforte Alessandro , Carbone Daniele
Published: February 2023

We present results of repeated absolute gravity and GPS measurements, carried out at Mt. Etna volcano between 2009 and 2018. Absolute gravity measurements are rarely performed along arrays of stations on active volcanoes and, through our unprecedented dataset, we highlight the possibilities of this method to track underground mass changes over long time-scales.Analysis of the residual absolute gravity data and ground deformation reveals a cycle of gravity increase and uplift during 2009 to 2011, followed by gravity decrease and subsidence during 2011 to 2014.Data inversion points to a common mass and pressure source, lying beneath the summit area of the volcano, at depth of ~5 km b.s.l. The bulk volume change inferred by the inversion of the deformation data can account for only a small portion of the mass change needed to explain the correspondent gravity variations. We propose that the observed relationship between gravity and vertical deformation was mostly due to the compressibility of the magma in the inferred reservoir, which, in turn, was enhanced by the presence of exsolved gas.Overall, the gravity and deformation data we present reveal a cycle of magma recharge (2009 – 2011) and discharge (2011 – 2014) to/from the inferred storage zone. During the recharge phase only degassing occurred from the summit craters of Mt. Etna. During the following phase of discharge, the magma lost from the reservoir at ~5 km b.s.l. fed the exceptional phase of volcanic activity during 2011 to 2014, when tens of lava fountaining episodes took place.
Thermospheric mass density variations based on GRACE-FO during the ascending phase of solar cycle 25
Authors: Wang Bowen , Meng Xiangguang , Sun Yueqiang , Männel Benjamin , Wickert Jens
Published: February 2023

High-resolution thermospheric mass density (TMD) measurements from Low Earth Orbit (LEO) Satellites are valuable to accurately estimate the short-term atmosphere abrupt disturbances, triggered by magnetospheric forcing. A good characterization of TMD variation ahead of the arrival geomagnetic storms can benefit LEO operations and crucial for both orbit propagation and collision avoidance. In this contribution, we will reveal the most probable feature of TMD variation during the initial stage of solar cycle 25, at the same time, we proved Wygant function as a better geomagnetic events indicator.In this study, GRACE-FO 10s accelerometer-derived TMD measurements were employed and normalized at altitude of 505km by the NRLMSISE-00 (Naval Research Laboratory Mass Spectrometer and Incoherent Scatter Radar Exosphere 2000) empirical atmosphere model to investigate the status of solar cycle 25 between September 1 and December 31, 2020. With the high-inclination orbit global coverage, three magnetic latitude regions were separated and divided into day and nighttime using magnetic local times (MLT). 4-month enhancing disturbances observations suggest solar activities will shift from its relatively quiet condition to a much more active behavior, which reveal unexpected dependencies on the temporal and spatial characteries. Our detailed analysis shows that (1) TMD spreads from high latitudes to low latitudes and as same as time lag, (2) TMD enhancement in the Southern hemisphere is more intense than in the Northern one, reaching peak value around 15:00 MLT; geomagnetic activities cause TMD to increase up to 0.86×10-13 kg/m3 at night side, 3.4×10-13 kg/m3 at day side, and (3) the TMD enhancement was symmetric in both N- and S- hemispheres before the equinox. In general, thermospheric mass density analysis reveals the significant impact of solar and geomagnetic activities, providing the most relevant and probable characteristic of the TMD disturbances driven by solar wind.Additionally, we try to use different geomagnetic indices for a complete description of geomagnetic storms and their phases. The S10.7 index is used as a proxy for solar irradiation. These indicators show high correlation with the TMD variation during recurrent geomagnetic activities. What’s more, the cross-correlation analysis reflects a high correlation of to the Wygant function EWAV found both at three latitude bins.Even thought our study is considered a minor to moderate geomagnetic storm of the upcoming solar cycle 25 maximum, the high-speed stream injection into the thermosphere still caused thermosphere expansion that significantly enhanced the neutral density in the LEO environment. Therefore, all these findings provide a possibility to improve our understanding of LEO orbital drag.
The role of the Pacific-Antarctic Ridge in establishing the northward extent of Antarctic sea-ice
Authors: Ferola Antonino Ian , Cotroneo Yuri , Wadhams Peter , Fusco Giannetta , Falco Pierpaolo , Budillon Giorgio , Aulicino Giuseppe
Published: February 2023

Monitoring the Antarctic sea-ice is essential for improving our knowledge of the Southern Ocean. We used satellite sea-ice concentration data for the 2002-2020 period to retrieve the sea-ice extent (SIE) and analyze its variability in the Pacific sector of the Southern Ocean. Results provide observational evidence of the recurring formation of a sea-ice protrusion that extends to 60° S at 150° W during the winter season. These activities are carried on in the framework of the ACCESS and SWIMMING projects of the PNRA.Our findings show that the northward deflection of the southern Antarctic Circumpolar Current front is driven by the Pacific Antarctic Ridge (PAR) and is associated with the enhanced sea-ice advance. The PAR also constrains anticyclonic and cyclonic eddy trajectories, limiting their interaction with the sea-ice edge. These factors, within the 160° W - 135° W sector, determine an average SIE increase of 61,000 km2 and 46,293 km2 per year more than the upstream and downstream areas, respectively.
Magnetic Reconnection as a Dissipation Mechanism for Magnetic Switchbacks
Authors: Suen Gabriel , Owen Christopher , Verscharen Daniel , Horbury Timothy , Louarn Philippe
Published: February 2023

Context: Magnetic switchbacks are localised polarity reversals in the radial component of the heliospheric magnetic field. Observations from Parker Solar Probe (PSP) have shown that they are a prevalent feature of the near-Sun solar wind. However, observations of switchbacks at 1 au and beyond are less frequent, suggesting that these structures are dissipated by yet-to-be identified mechanisms as they propagate away from the Sun.Aims: We estimate the timescales over which magnetic switchbacks may be dissipated by magnetic reconnection and evaluate the viability of reconnection as a dissipation mechanism for switchbacks.Methods: We analyse magnetic field and plasma data from the magnetometer and Solar Wind Analyser instruments aboard Solar Orbiter between 10 August and 30 August 2021. During this period, the spacecraft was 0.6 – 0.7 au from the Sun.Results: We identify three instances of reconnection occurring at the trailing edge of magnetic switchbacks. Using hodographs and Walen analysis methods, we find that the reconnection exhaust region for all three events are bound by rotational discontinuities in the magnetic field, consistent with existing models describing the properties of reconnection in the solar wind. Based on these observations, we propose a scenario through which reconnection can dissipate a switchback and we estimate the timescales over which this occurs. We find that for our events the dissipation timescales are much shorter than the expansion timescale and thus, the complete dissipation of all three observed switchbacks would occur well before they reach Earth. Furthermore, assuming the observed reconnection rate has remained constant, and extrapolating back to an origin close to the Sun, we find that the spatial scale of these switchbacks would be considerably larger than is typically seen in the inner heliosphere. Hence, it is implied that the onset of reconnection must occur during transport in the solar wind. If typical, these results suggest that reconnection can play a significant role in dissipating switchbacks and could help explain the relative rarity of switchback observations at 1 au.
Linking water-society interactions in Chennai, India through the DPSIR framework
Authors: Rosado Daniel , Fárez-Román Valeria , Müller Felix , Nambi Indumathi , Fohrer Nicola
Published: February 2023

Cities in all continents are suffering from water scarcity. Projected rapid population growth and urbanization together with climate change will put even more pressure on urban water resources and, therefore, the number of large cities and global urban population facing water scarcity will significantly increase by 2050. Forecasts look particularly worrying in India, where the urban population facing water scarcity is expected to be the highest in the world by 2050. Chennai, India´s fourth-largest urban agglomeration, had in 2019 its worst water crisis in 30 years, after its four major reservoirs dried up and the city was relying solely on water tankers.Although addressing water management in cities with complex scenarios requires applying an integrated urban water management approach, there is no internationally standardized indicator framework for it. Therefore, this study aims at applying the Drivers-Pressures-States-Impacts-Responses (DPSIR) framework, a causal framework adopted by the European Environment Agency for describing the interactions between society and the environment, on Chennai’s water resources to help stakeholders implementing sustainable management strategies.Scientific literature, public administration and interested parties were consulted. The main drivers identified were population growth and economic development which generate pressures on land use, water demand and waste generation. Due to these pressures, Chennai experiences rapid urbanization, water scarcity and pollution, and biodiversity loss. This has led to impacts such as the loss of aquatic ecosystems, low water table and quality, and reduction in biodiversity and human health. As a response, authorities and non-governmental organizations implemented measures to increase the availability of drinking water like dams, inter-basin transfers, desalination plants, groundwater pumping, and rainwater harvesting. Also, the conditions of aquatic ecosystems have been improved through urban planning, new sewage treatment plants, ecosystem restoration projects and the implementation of water regulations. However, Chennai is expected to keep facing difficulties to achieve a proper water management. A mix of measures such as more infrastructure for water harvesting, new sewage treatment plants, or a more efficient waste management system are recommended.
An overview of the planetary theory of solar activity variability and its importance for understanding climate oscillations
Authors: Bianchini Antonio , Scafetta Nicola
Published: February 2023

The complex dynamics of solar activity appear to be controlled by a number of individual oscillations from the monthly to the millennial scales, the most well-known of which is the 11-year Schwabe sunspot cycle. These oscillations are important also because many of them characterize the oscillations found in the climate of the Earth and could be used for climate change forecast purposes. However, the physical cause of the solar oscillations is still debated. Commenting on the origin of the 11-year sunspot cycle, Johann Rudolf Wolf (1859, MNRAS 19, 85–86) conjectured that “the variations of spot frequency depend on the influences of Venus, Earth, Jupiter, and Saturn.” There are only two options: either the solar activity changes are solely controlled by internal solar dynamo mechanisms or the solar dynamo itself is partially synchronized by external harmonic planetary forcings. The former hypothesis is today shared by the majority of solar scientists; the latter has been recently advocated by an increasing minority of solar scientists, and the debate is still going on. Here we overview the numerous pieces of evidence supporting a planetary theory of solar activity variability by demonstrating that the many planetary harmonics and the orbital invariant inequalities that characterize the planetary motions of the solar system from the monthly to the millennial time scales are not randomly distributed but clearly tend to cluster around some specific values that also match those of the main solar activity cycles. We also show that planetary models have even been able to predict the time phase of the solar oscillations including the Schwabe 11-year sunspot cycle. Although planetary tidal forces are weak, we review a number of mechanisms that could explain how the solar structure and the solar dynamo could get tuned to the planetary motions. In particular, we discuss how the effects of the weak tidal forces could be significantly amplified in the solar core by an induced increase in the H-burning. Mechanisms modulating the electromagnetic and gravitational large-scale structure of the planetary system are also discussed.Main Reference:Scafetta N and Bianchini A (2022) The Planetary Theory of Solar Activity Variability: A Review. Front. Astron. Space Sci. 9:937930. doi: 10.3389/fspas.2022.937930Scafetta, N. (2020). Solar Oscillations and the Orbital Invariant Inequalities of the Solar System. Sol. Phys. 295, 33. doi:10.1007/s11207-020-01599-y
Initial meteorological conditions and eruption source parameters control on volcanic forcing
Authors: Krüger Kirstin , Zhuo Zhihong , Fuglestvedt Herman , Mills Mike , Toohey Matthew
Published: February 2023

Studying impacts of past volcanic eruptions on climate and society relies on volcanology, paleo proxies and archaeological records next to climate model simulations. Here we newly study the control of varying meteorological conditions and eruption source parameters on the volcanic forcing. Simulating explosive tropical and extratropical Northern Hemisphere (NH) volcanic eruptions are carried out by co-injecting sulfur and halogens into the stratosphere with the CESM2(WACCM) model including aerosol, chemistry, climate, and earth system processes. We consider different initial meteorological conditions (ENSO, QBO, and polar vortex states) and varying eruption source parameters injecting 17 Tg and 200 Tg of SO2 together with scaled halogens, at 24 km altitude and 15° N and 64° N latitude, during January and July pre industrial 1850 conditions. Varying initial meteorological conditions reveal a similar large impact on the volcanic forcing (SO2, SO4, aerosol optical depth, halogens) as varying source parameters for both tropical and NH extratropical eruptions. Our results are compared with available model experiments from MAECHAM5-HAM. Consequences and uncertainties of volcanic forcing and responses to past and future eruptions are discussed. 
Analysis of vegetation biodiversity by means of abundance-based metrics and agent-based models applied to spaceborne multispectral, hyperspectral and SAR images
Authors: Nico Giovanni , Monaco Manilo , Masci Olimpia
Published: February 2023

Forest biodiversity is one of the seven thematic programmes established by the Conference of the Parties within the Convention on Biological Diversity. The topic of identification, monitoring, definition of indicators and assessment of biodiversity is one of the cross-cutting issues  of the Convention to collect, maitain and organize biodiversity information.The huge amount, spectral diversity, regular and dense acquisition plan of current Earth Observation spaceborne missions provides a means to monitor and evaluate the vegetation biodiversity. In this work we present the results of an application of multispectral, hyperspectral and SAR satellite images to map the vegetation biodiversity in National Parks of Gargano, Alta Murgia, Cilento-Vallo di Diano-Alburni, Appennino Lucano Val D’Agri Lagonegrese and Pollino, all located in Southern Italy. For each of the aforementioned parks, study areas have been selected. Sentinel-2 and PRISMA images have been used to compute different vegetation indeces to analyze the different phenological properties of plants and the impact of the interaction soil-vegetation on the reflection coefficient measured by the sensors. Furthermore, Sentinel-1 images have been used to compute the radar vegetation index and the interferometric Synthetic Aperture Radar (SAR) coherence.The maps of all the above multi- and hypespectral indeces and SAR products have been analyzed in terms of two abundance-based metrics and used within a agent-based model to quantify vegetation biodiversity. The Shannon entropy and Rao’s Q metrics haven been implemented and applied to the matrices of vegetation indeces and SAR products. These two computational tools are compared in terms of their ability to describe the diversity of the agro-forestry landspace. Furthermore, the landscape heterogeneity has been modelled by intelligent agents that move through the selected areas in a simulated environment and collect information on vegetation indices in order to measure their diversity. The output of the agent-based model has been compared to the results obtained by the abundance-based metrics to identify mathematical tools useful for the conservation planning of critical habitats.
The deep space environment simulation vacuum chamber and large radiometry calibration facilities at Shenzhen University
Authors: Zhu Ping , Liu Huizeng , Song Mi , Huang Shaopeng , Li Qingquan
Published: February 2023

The space environment simulation facilities are the key to any successful space experiments and missions. To characterize and validate the optical space instrument, Shenzhen university is started to design a large vacuum chamber with various integrated standard radiation sources, covering a wavelength range from UV to near-infrared. The large radiometry calibration facilities (LRCF) will be traced to standard scale factors such as those maintained by the World Radiation Center at the Physikalisch Meteorologisches Observatorium Davos, Switzerland. In this presentation, we will introduce the LRCF and the broadband radiometer developed for the moon-based earth observation system and how to use the LRCF to characterize the radiometer.
Water Extent Measurements with Sentinel-6 Fully - Focussed SAR data
Authors: Gómez Olivé Adrià , Gibert Ferran , Garcia-Mondéjar Albert , McKeown Charlie
Published: February 2023

The Sentinel-6 mission, launched in November 2020, carries a radar altimeter operating in open burst with a PRF high enough (~9kHz) to perform the focussing of whole target observation echoes in a fully coherent way. Furthermore, such a feature allows improvement of the along-track resolution down to the theoretical limit of around 0.5 m when processing the data with a Fully-Focussed SAR (FFSAR) algorithm. This resolution increment actually represents a revolutionary step with respect to the ~300 m along-track resolution provided by current operational processors based on Unfocussed SAR algorithms, commonly used in radar altimeters with a closed burst chronogram, such as CryoSat-2 and Sentinel-3. In this contribution, we explore new applications over inland water surfaces, such as reservoirs or lakes derived from the new Sentinel-6 FFSAR products. Indeed, a FFSAR Ground Prototype Processor (GPP), developed by isardSAT and based on the backprojection algorithm [1], has been used to process altimetry data and generate FFSAR radargrams of off-nadir inland targets located within certain observation constraints. As a main outcome, we present a methodology to geo-reference and estimate the extension of water bodies located on unambiguous across-track targets and that present strong seasonal extension variability. Validation of the method has been performed by comparing the FFSAR water extent measurements derived from Sentinel-6 against optical (Sentinel-2) measurements and in-situ observations. [1] Egido, Alejandro and Walter H. F. Smith. “Fully Focused SAR Altimetry: Theory and Applications.” IEEE Transactions on Geoscience and Remote Sensing 55 (2017): 392-406.
Translating hydrology research into practice: A Canadian Perspective
Authors: Pietroniro Alain , Rokaya Prabin , Schuster-Wallace Corinne , Pomeroy John W
Published: February 2023

Hydrology research is regarded as vital for advancing human development and environmental conservation through improved hydrological process understanding and by devising solutions to address water management challenges. This is particularly acute in a time of global change and the need to find pathways to water sustainability.  Success for research in hydrology is often measured through quantitative research outputs, such as the number of journal publications, citation indices, number of students trained, patents, and external research funding. User involvement in the research and development process is rarely considered a metric for success in hydrology. Despite successful scientific or engineering advancements, a greater scientific understanding of hydrology and ever-increasing publications, much of the research has limited uptake by practitioners and implementation into practice, leading to a growing gap between research and practice.  This lack of utilisation is not due to a lack of need by users, but rather is a symptom of the disconnect between these advances and research that would most add value to practitioners and their application needs. We explore some outstanding challenges in translating academic research into practice and make some recommendations to bridge the increasing gaps between research and practice through a transdisciplinary approach, user engagement metrics in funded research and strong knowledge mobilization. We also discuss the success and challenges of these approaches in the Global Water Futures program along with lessons learned.  
The Miniaturized Electron Proton Telescope, MERiT onboard Lunar Gateway
Authors: Kanekal Shri ,   The Miniaturized Electron Proton Telescope
Published: February 2023

The Lunar Gateway or the Gateway, part of NASA’s Artemis program, is a space station that will orbit around the moon. This cis-lunar Gateway platform provides the opportunity for Heliophysics investigations to advance our knowledge of the coupled Sun-Earth system and the opportunity to better understand the radiation environment in order to support and improve crew safety and operations at the Moon and beyond. The Heliophysics Environmental and Radiation Measurement Experiment Suite (HERMES) is a suite of instruments placed on the outside of the Habitation and Logistics Outpost (HALO)  to monitor the Sun’s radiation environment and space weather. HERMES, led by NASA’s Goddard Space Flight Center, will monitor  solar particles critical to scientific investigations of the Sun including the solar winds. Additonal suite of instruments provided by ESA, the European Radiation Sensors Array (ERSA) will complement space weather studies.

We report here on the energetic particle instrument, the  Minaturized Electron Proton Telescope (MERiT) on board HERMES. MERiT is  designed to measure electrons and protons in the energy range ~0.3-9. MeV and ~1-190 MeV in 11 and 20 differential energy channels respectively. MERiT is a solid state detector telescope with  two sensor heads: one looking sunward and the other anti-sunward. MERiT will help advance our understanding of solar energetic particles, low energy cosmic rays and energetic electrons in the magnetospheric tail. We will describe the instrument in detail and the science topics it is expected to address. Lunar Gateway is currently expected to launch in October 2025.
VOLTURMAC project: a bet of INTERREG V Spain-Portugal program for the development of volcano-tourism in the Macaronesia region
Authors: Dóniz-Paéz Javier , Pérez Nemesio M. , Hernández Pedro A. , Beltrán-Yanes Esther , Pérez Yurena , Padrón Nestor , Delgado Nayra , Reyes Juan Carlos , Duarte Marco , Paim Márcia , Correia Assis , Viera Isabel , Alfama Vera , Silva Sonia V. , Martins Carla , Pereira José M. , Vasconcelos Manuel , Delgado Adlisa
Published: February 2023

Although volcanoes present a risk to society, they also represent an opportunity for the development and socio-economic sustainability of their territories. Its main benefits are associated with the diversity of resources offered by volcanic landscapes: geothermal energy, agriculture, building materials, tourism, etc. The volcanic nature of the Macaronesia region (Azores, Madeira, Canarias and Cape Verde archipelagos) constitutes an important geoturistic claim as a result of the great beauty and the landscape diversity of the volcanic territories, offering the possibility of experiencing closely the force of nature and the cultural and spiritual wealth of the population that lives in safe conditions thanks to the existence of programs aimed at reducing volcanic risk. The objective of the VOLTURMAC project (MAC2 / 4.6c / 298), funded by the INTERREG VA Spain-Portugal MAC 2014-2020 Territorial Cooperation Program, is to contribute to the strengthening of the conservation, protection, promotion and development of natural and cultural heritage associated with the volcanic phenomenon in Macaronesia through tourism volcano and contribute to the diversification of the tourist offer of the four Macaronesian archipelagos. To achieve the main objective of this project, nine different activities are proposed and grouped around three main axes: (1) analyze, evaluate and identify the potential of volcano-tourism in Macaronesia; (2) create geo-itineraries and touristic geo-routes that value the natural and cultural resources of the volcanic landscapes of Macaronesia by identifying, selecting, mapping and evaluating geosites, geomorphosites and sites of geotourist interest (SGIs) and (3) promoting and strengthening training on natural and cultural resources linked to the volcanic phenomenon in the tourism sector for all tourism actors, but with special relevance for those in the business field and tourist guides. (Volturmac-MAC2/4.6c/298).