bluuebunny/crossref_metadata_2025 huggingface dataset:
Utilizing machine learning techniques along with GPS ionospheric TEC maps for potentially predicting earthquake events
Authors: Reuveni Yuval , Asaly Sead , Inbar Nimrod , Gottlieb Leead
Published: March 2022

The scientific use of ground and space-based remote sensing technology is inherently vital for studying different lithospheric-tropospheric-ionospheric coupling mechanisms, which are imperative for understanding geodynamic processes. Current remote sensing technologies operating at a wide range of frequencies, using either sound or electromagnetic emitted waves, have become a valuable tool for detecting and measuring signatures presumably associated with earthquake events. Over the past two decades, numerous studies have been presenting promising results related to natural hazards mitigation, especially for earthquake precursors, while other studies have been refuting them. While highly impacting for geodynamic processes the controversy around precursors that may precede earthquakes yet remains significant. Thus, predicting where and when natural hazard event such as earthquake is likely to occur in a specific region of interest still remains a key challenging task in geo-sciences related research. Recently, it has been discovered that natural hazard signatures associated with strong earthquakes appear not only in the lithosphere, but also in the troposphere and ionosphere. Both ground and space-based remote sensing techniques can be used to detect early warning signals from places where stresses build up deep in the Earth’s crust and may lead to a catastrophic earthquake. Here, we propose to implement a machine learning Support Vector Machine (SVM) technique, applied with GPS ionospheric Total Electron Content (TEC) pre-processed time series estimations, extracted from global ionospheric TEC maps, to evaluate any potential precursory caused by the earthquake and is manifested as ionospheric TEC anomaly. Each TEC time series data was geographically extracted around the earthquake epicenter and calculated by weighted average of the four closest points to evaluate any potential influence caused by the earthquake. After filtering and screening our data from any solar or geomagnetic influence at different time scales, our results indicate that with large earthquakes (> 6 [Mw]), there is a potentially high probability of gaining true negative prediction with accuracy of 85.7% as well as true positive prediction accuracy of 80%. Our suggested method has been also tested with different skill scores such as Accuracy (0.8285), precision (0.85), recall (0.8), Heidke Skill Score (0.657) and Tue Skill Statistics (0.657).
Classifying earthquakes and mining activity with deep neural networks
Authors: Horváth András , Timkó Máté , Kiszely Márta , Bozóki Tamás , Bozsó István , Kuslits Lukács
Published: March 2022

Earthquake detection and phase picking are central problems of seismic activity analysis. Traditional approaches [1] and machine learning methods [2] are applied in this domain, typically performing well on commonly investigated standard datasets reaching above 99% accuracy in seismic activity detection.

 

Unfortunately, most databases in the literature contain only earthquake data as detectable activities and spurious activities such as mining are not included in these datasets. We have investigated a recently published deep neural network-based method [3] and found that these detectors are fooled by mining activity.

 

To solve this problem, we have created a complex dataset that contains 1200 independently recorded mining and earthquake activities from Central Europe. Our dataset poses a more complex problem than commonly investigated datasets such as the STanford EArthquake Dataset and can be viewed as an extension of that.

 

We have trained a convolutional neural network containing five convolutional and three fully-connected layers to classify these signals on this dataset and reached a 94% classification accuracy, which demonstrates that the categorization of mining activity and earthquakes is possible with modern machine learning approaches.

[1] Galiana-Merino, J. J., Rosa-Herranz, J. L., & Parolai, S. (2008). Seismic P Phase Picking Using a Kurtosis-Based Criterion in the Stationary Wavelet Domain. IEEE Transactions on Geoscience and Remote Sensing, 46(11), 3815-3826.

 

[2] Zhu, W., & Beroza, G. C. (2019). PhaseNet: a deep-neural-network-based seismic arrival-time picking method. Geophysical Journal International, 216(1), 261-273.

 

[3] Mousavi, S. M., Ellsworth, W. L., Zhu, W., Chuang, L. Y., & Beroza, G. C. (2020). Earthquake transformer—an attentive deep-learning model for simultaneous earthquake detection and phase picking. Nature communications, 11(1), 1-12.
Impacts of Fires on Convective Cloud Features in Southeast Asia: Variability with ENSO
Authors: Takeishi Azusa , Wang Chien
Published: March 2022

Located right in the middle of the tropical warm pool, convective activities over Southeast Asia are subject to interannual variability in sea surface temperature due primarily to varying phases of the El Niño-Southern Oscillation (ENSO). Observations often show a reduction in the amount of rainfall during El Niño and its increase during La Niña over Southeast Asia. Because of this interannual variability in rainfall and humidity, emissions of aerosol particles and their abundance in the atmosphere, often manifested in aerosol optical depths, are also subject to interannual variability; they increase during El Niño and are reduced during La Niña on average. Our previous study has shown an impact of biomass-burning aerosols on convective clouds, which enhanced rainfall and generally invigorated convection. Here we present the comparison of this aerosol effect among different years with different ENSO phases. We utilized month-long cloud-resolving simulations by the WRF-CHEM model that are capable of including both aerosol direct and indirect effects. The extensive simulation domain size and time period enabled the inclusion of a wide range of contributors to cloud development over the area, from aerosol activation to ENSO-affected meteorology. We show whether the invigoration effect that we found from the year of strong El Niño in 2015 still holds in years of weaker El Niño or even during La Niña.
The GOP DORIS analysis center: data processing and innovation strategy 
Authors: Stepanek Petr , Filler Vratislav
Published: March 2022

Geodesy Observatory Pecný (GOP) analysis center is one of the International DORIS Service (IDS) analysis centers. GOP fully contributed to the IDS combination of the ITRF2020, reaching various improvements in comparison to the ITRF2014 reprocessing. GOP also participates in the IDS operational solutions. A major progress has been reached in the data preprocessing strategy, South Atlantic Anomaly mitigation and satellite orbit & attitude modeling.  improvements in the internal strategy together with an updating of external models to the recent standards resulted in the significant improvement in the station positioning including of the stability of the transformation parameter time series. Also the pole coordinates estimation accuracy has been increased. This improvement is illustrated comparing the statistics of GOP contributions to the IDS combination for the ITRF2014 and ITRF2020. Important improvement in the GOP processing capability is the adaption of the software tools to the RINEX data processing, getting closer to raw DORIS measurement. In addition, we present initial results of the data processing and a modeling verification for the post-ITRF2020 data from the DORIS satellites Sentinel-6A, HY-2C and HY-2D.
Thermochemical modeling of gas and ice giant planets
Authors: Cavalié Thibault , Lunine Jonathan , Olivia Venot
Published: March 2022

Understanding the processes that lead to the formation of giant planets in planetary systems is crucial, because these planets are the architects of more complex systems harbouring rocky planets that form over longer timescales. Measuring the deep elemental abundances of giant planets is one of the keys to constrain their formation. After the Galileo probe measurements at Jupiter, Juno is making observations to constrain the deep oxygen abundance of the planet. Fewer measurements are available at Saturn, and even more so at Uranus and Neptune. The lack of in situ probes or sensitive enough remote sensing measurements planned for these planets, thermochemical computations offers the means to help constrain the deep elemental abundances by reproducing the abundances of observable minor species which are chemically linked with the deep and main reservoirs of the main elements. This is particularly true for oxygen, which is mainly carried by water, a condensible species in giant planet atmospheres. Water ice trapped the other heavy elements during planetesimal formation beyond the snowline. The ratios between oxygen and the other elements bear implications on the form under which water condensed beyond the snowline (amorphous ice vs. clathrates). 
In this paper, we will present and discuss the results of our model for the solar system giant planets and compare the situations of gas vs. ice giant planets. 
Suitability of soil carbon certificates for climate change mitigation
Authors: Paul Carsten , Don Axel , Bartkowski Bartosz , Wiesmeier Martin , Weigl Sebastian , Mayer Steffi , Wolf André , Dönmez Cenk , Helming Katharina
Published: March 2022

There is growing awareness of the role that agricultural soils can play for climate change mitigation. Agricultural management that increases soil organic carbon (SOC) stocks constitutes a nature-based solution for carbon dioxide removal. As soils store about twice the amount of carbon found in the atmosphere, even small relative increases could significantly reduce global warming.

However, increasing SOC requires management changes that come with costs to the farmers. In this regard, soil carbon certificates could provide a much-needed financial incentive: Farmers register their fields with commercial providers who certify any SOC increase achieved during a set period of time. The certificates are then sold on the voluntary carbon-offset market. We analysed the suitability of soil carbon certificates for climate change mitigation from the perspectives of soil sciences, agricultural management, and governance. In particular, we addressed questions of quantification, additionality, permanence, changes in emissions, leakage effects, transparency, legitimacy and accountability, as well as synergies and trade-offs with other societal targets.

Soil properties and the mechanisms by which carbon is stored in soils have strong implications for the assessment. Soils have a limited storage capacity, and SOC is not sequestered but its SOC stocks are the dynamic result of plant derived inputs and losses mainly in the form of microbial respiration. The higher the SOC stock, the higher the annual carbon inputs that is needed to maintain it. If carbon friendly management is discontinued, elevated SOC levels will therefore revert to their original level.

We found that while changes in agricultural management that increase SOC are highly desirable and offer multiple-co benefits with climate change adaptation, soil carbon certificates are unsuitable as a tool. They are unlikely to deliver the climate change mitigation they promise as certificate providers cannot guarantee permanence and additionality of SOC storage over climate relevant time-frames. Where the certified carbon storage is non-permanent or fails to meet criteria of additionality, the use of such certificates to advertise products as “carbon-neutral” may be construed as false advertising.
Development of continuous and discontinuous gullies in the Moldavian Plateau of Romania
Authors: Niacsu Lilian , Ionita Ion , Poesen Jean , Fullen Michael
Published: March 2022

Intense gully erosion has sculptured remarkable channels into the Moldavian Plateau of eastern Romania. These permanent gully types are: (1) discontinuous gullies, mostly located on hillslopes and (2) large continuous gullies in valley bottoms.

This study seeks to improve our understanding of the development of 1) continuous gullies over six decades (1961-2020) and 2) discontinuous gullies over variable time-scales (mostly 17-30 years, but also including data collected since 1961) by providing quantitative information on gully evolution and processes. Several methods were used to measure and estimate gully growth. These include intensive field monitoring using the ‘stakes grid method,’ repeated levelling until 2019, analysis of aerial photographs and Caesium-137 analysis.

            As regards the continuous gullies, results indicate that gully erosion rates have significantly decreased since 1981. The mean linear gully head retreat rate (LGHR) of 7.7 m yr-1 over 60 years was accompanied by a mean areal gully growth rate in plan (AGG) of 213 m2 yr-1.  However, erosion rates between 1961-1980 were 4.0 times larger for LGHR and 5.9 times more for AGG compared to those for 1981-2020. Two regression models indicate that annual precipitation (P) is the primary controlling factor, explaining 57% of the LGHR and 53% of the AGG rate. The contributing area (CA) follows, with ~33%. Only 43% of total change in LGHR and 46% of total change in AGG results from rainfall-induced runoff during the warm season. Accordingly, the cold season (with associated freeze-thaw processes and snowmelt runoff) has more impact on gully development. The runoff pattern, when flow enters the trunk gully head, is largely controlled by the upper approaching discontinuous gully.

The discontinuous gullies occur as single, successive chains or clusters. These are associated with small catchments (usually <100 ha in area) and ephemeral peak runoff discharges are usually ≤2 m3 s-1. The mean LGHR for 31 gullies was 0.97 m yr-1, indicative of a relatively small erosion rate. However, their ‘pulsatory’ development was mostly controlled by runoff accommodation when runoff enters and is conveyed through a gully. We further analysed the changing runoff pattern or ‘variable-geometry flow.’ The R2 of the relation between LGHR or AGG and  (CA) indicated a weak correlation for discontinuous gullies.
Collisional Evolution of the Inner Zodiacal Cloud: In-Situ observations from PSP and implications for Airless Body Surfaces
Authors: Szalay Jamey , Pokorný Petr , Malaspina David , Pusack Anna , Horányi Mihály , DeLuca Michael , Bale Stuart , Battams Karl , Gasque Claire , Goetz Keith , Krüger Harald , McComas David , Schwadron Nathan , Strub Peter
Published: March 2022

The zodiacal cloud is one of the largest structures in the solar system and strongly governed by meteoroid collisions near the Sun. Collisional erosion occurs throughout the zodiacal cloud, yet it has been historically difficult to directly measure. After transiting the inner-most regions of the solar system with Parker Solar Probe (PSP), we find that its dust impact rates are consistent with at least three distinct populations: bound zodiacal dust grains on elliptic orbits (α-meteoroids), unbound β-meteoroids on hyperbolic orbits, and a third population of impactors that may be either direct observations of discrete meteoroid streams or their collisional by-products (“β-streams”). The β-stream from the Geminids meteoroid stream is a favorable candidate for the third impactor population. β-streams of varying intensities are expected to be produced by all meteoroid streams, particularly in the inner solar system, and are a universal phenomenon in all exozodiacal disks. We discuss these recent PSP observations of the dust environment in the very inner solar system, provide constraints on their relative densities and fluxes, and discuss the erosion rate of zodiacal material.

These observations are also directly relevant for understanding the impactor and space weathering environment experienced by airless bodies in the inner solar system. Since the discovery of the Moon's asymmetric ejecta cloud, the origin of its sunward-canted density enhancement has not been well understood. Ejecta is produced from β-meteoroids which impact the Moon's sunward side at similar locations to this previously unresolved asymmetry. These small grains are submicron in size, comparable to or smaller than the lunar regolith particles they hit, and can impact the Moon at very high speeds ~100 km s-1.  Incorporating β-meteoroid fluxes observed by the Pioneers 8 & 9, Ulysses, and Parker Solar Probe spacecraft as a newly considered impactor source at the Moon, we find β-meteoroid impacts to the lunar surface can explain the sunward asymmetry observed by LADEE/LDEX. We discuss these observations and how this finding suggests β-meteoroids may appreciably contribute to the evolution of other airless surfaces in the inner solar system.
The Spatial Extent of Carbohydrate Sharing in the Wood-Wide Web Varies with Climate and with Taxonomy of Ectomycorrhizal Fungi : Insights from the Swiss Forest FACE
Authors: Hobbie Erik , Keel Sonja , Steinmann Katharina , Wilhelm Markus , Saurer Matthias , Siegwolf Rolf , Körner Christian
Published: March 2022

∙ To assess how belowground mycorrhizal networks may share resources, we used δ13C, δ15N, and C/N measurements to calculate spatial and temporal dynamics of carbohydrate and amino acid movement through ectomycorrhizal networks of mature trees.

∙ Canopies of 14 deciduous trees were continuously labeled with 13C-depleted CO2 from 2001-2005 (Swiss Forest FACE) and the 13C label traced into ectomycorrhizal sporocarps.

∙ Sporocarps derived 69±5%, 30±6%, and 16±7% of their carbon from labeled trees in the elevated (beneath labeled trees), 0-6 m, and 6-12 m distances, respectively. Sporocarp δ13C correlated positively with C/N under elevated CO2 and negatively elsewhere, reflecting that high-δ13C carbohydrates from surrounding trees contributed to sporocarps under elevated CO2 and low-δ13C carbohydrates from elevated CO2 trees contributed to sporocarps elsewhere. Sporocarp δ15N increased in Cortinarius with decreasing δ13C, suggesting that greater hyphal growth with elevated CO2 sequestered 15N-depleted N from sporocarp formation. Sporocarp loge C/N decreased during the 2004 growing season and the contribution of 13C-depleted carbon from elevated CO2 plants decreased at the 0-6 m and 6-12 m distances, suggesting decreased carbohydrate availability and network transport that year. In contrast, sporocarp loge C/N increased during the 2005 growing season and the contribution of 13C-depleted carbon from elevated CO2 plants increased at the 0-6 m distance, suggesting increased carbohydrate availability and network transport that year. Relative to other taxa, elevated CO2 reduced C/N by 15% and ambient CO2 increased C/N by 5% in taxa exclusively associated with deciduous trees, suggesting increased carbohydrate sharing by the deciduous-associated taxa.

∙ These patterns indicated that 1) carbohydrates (high C/N), not amino acids (low C/N), were preferentially transferred between regions differing in source δ13C, 2) sporocarp C/N reflected yearly plant productivity, 3) network transport was influenced by climate, and 4) taxonomy influenced transport dynamics belowground.
Increased frequency of urban floodings in coastal Indian cities caused by variation in monsoon rainfall: Influencing factors, challenges, and solutions
Authors: Mohanavelu Aadhityaa , Soundharajan Bankaru-Swamy
Published: March 2022

Coastal cities in India houses nearly 100 million people and are evenly distributed across India’s 7516-kilometer coastline. These cities are important centers of socio-economic activities in the country and are some of the densely populated regions in the world. A number of studies recently have predicted that there is a risk of substantial portions of these cities’ areas being lost to the sea due to sea-level rise in the next few decades, since a major portion of these cities are at a near zero elevation from the mean sea level (M.S.L). Further, in the past few decades, major coastal cities in India have been repeatedly affected by recurrent extreme rainfall events and subsequent floodings. Several studies document that rapid change in the Indian monsoon, increased frequency in the formation of cyclones and the swift changes in the hydro-climatic regime in the Indian Ocean are the major contributors to the occurrence of these extreme precipitations events. While we can safely conclude that these events are likely to occur more frequently in the future, it is important to understand the factors that control and influence these events, comprehend how the cities are and will be affected, and develop feasible policy changes and mitigation action for effective governance. In this paper, we have taken the case of Chennai – an important coastal city located in the southern part of India that has been severely affected by extreme precipitation and subsequent flooding (notably the infamous 2015 Chennai floods) in the past few years, to study the influencing factors contributing to these events and the ground challenges faced by the government machinery in planning and managing these disasters effectively. Our findings indicate that there is a notable variation in the monsoon rainfall pattern in Chennai and the net annual rainfall in the city has increased significantly in the past decade (by ~15%). Further, we found that significant urban centers in the city, especially the regions that are at near zero elevation (± 5 meters above M.S.L) are more vulnerable to flooding, and the important contributing factors to the increased severity of the recent floodings include the lack of adequate stormwater drainage infrastructure and poor policy choice of converting natural surface water bodies (lakes and ponds) into towns during the past three to four decades. We also discuss the planning and execution of Chennai city’s mitigation action during the 2021 floods, analyze its success and shortcomings, and suggest sustainable and feasible policy changes and measures that can be adopted for better management of similar events in the future in other coastal cities as well.
Local solutions for global water security
Authors: Buytaert Wouter
Published: March 2022

Globally, the terrestrial water cycle is changing rapidly, because of human interventions in catchment hydrological processes, and changing meteorological boundary conditions. Many of these changes have a negative impact on the water security of people living within and nearby those catchments. Plenty of scientific evidence points to increasing intensities and frequencies of floods and droughts and degrading water resources in many parts of the world. While increasing water security is globally high on the policy agenda, there are clearly no easy solutions to this problem. Catchments are complex, idiosyncratic systems from which society draws many different resources and services, and many of these activities affect the local hydrological processes and the human benefits and risks that emanate from those. 

Achieving global water security is therefore only possible with solutions that are tailored to these specific local characteristics and realities. Analysing cases from the Andes, the Himalayas, and Africa, in this lecture I set out to identify crucial ingredients for successful catchment interventions, as well as some of the main scientific challenges that remain. I start from the conceptualization of a catchment as a complex adaptive system, governed by a unique combination of natural, social, and cultural processes. 

A first step then involves characterizing and quantifying these processes, which requires data collection and measuring. Although high-quality data are severely lacking in most of the world, many new opportunities are emerging. These range from remote sensing and pervasive in-situ sensor networks to novel data collection arrangements such as participatory monitoring and citizen science. In a next step, potential catchment interventions must be identified and evaluated. Also here, the toolbox of the catchment managers is growing continuously, with new concepts such as green infrastructure and nature-based solutions gaining traction. However, evaluating different potential interventions requires careful scenario analysis. Computational models, as well as uncertainty and risk assessment, are crucial tools to do so, but it also involves a thorough analysis of the (potentially complex and interacting) benefits and disbenefits that each intervention exerts on various population groups. Lastly, long term monitoring and evaluation of catchment interventions remains a formidable challenge, even though it is a crucial element to ensure that interventions effectively generate the anticipated benefits, to mitigate unexpected side-effects, and to adjust and adapt to constantly changing boundary conditions and catchment dynamics.
COVID-19 impacts on California methane point source emissions
Authors: Thorpe Andrew , Kort Eric , Duren Riley , Cusworth Daniel , Herner Jorn , Falk Matthias , Bue Brian , Yadav Vineet , Thompson David , Green Robert , Miller Charles , Frankenberg Christian
Published: March 2022

In the summer of 2020, the AVIRIS-NG airborne imaging spectrometer surveyed California’s Southern San Joaquin Valley and the South Bay (Los Angeles County) to identify anthropogenic methane point source plumes, estimate emission rates, and attribute sources to both facilities and emission sectors. These flights were designed to revisit regions previously surveyed by the 2016-2017 California Methane Survey (Duren et al., 2019) and to assess the impact of COVID-19 on emissions across multiple sectors. For the region flown by both the California Methane Survey (summer, fall 2016-2017) and the California COVID campaigns (summer, fall 2020), total emissions from point sources from the IPCC sectors for Energy Industries and Oil & Natural Gas were 34% lower during the 2020 flights. However, emission trends varied across different sectors. For the Energy Industries sector, there was a 19% decrease driven by reductions in refinery emissions consistent with a drop in production during 2020, which was offset in part with increases from powerplants. For the Oil & Natural Gas sector, emissions declined 35% and significant variability was observed at the oilfield scale. Emissions declined for all but the Buena Vista and Cymric oilfields with an observed relationship between production and emissions. These results indicate that imaging spectrometer surveys can characterize changes in anthropogenic emission profiles over time, including those associated with disruptive events like COVID-19.
South American freshwater fish diversity shaped by Andean uplift since the Late Cretaceous 
Authors: Boschman Lydian , Carraro Luca , Cassemiro Fernanda , de Vries Jorad , Altermatt Florian , Hagen Oskar , Hoorn Carina , Pellissier Loïc
Published: March 2022

South America is home to the highest freshwater fish biodiversity on Earth. The hotspot of species richness is located in the western Amazon Basin, and richness decreases downstream along the Amazon River towards the mouth at the Atlantic coast. This pattern contradicts the commonly observed positive relationship between stream size and biodiversity in river systems across the world. We investigate the role of river capture events caused by Andean mountain building and repeated episodes of flooding in western Amazonia in shaping the modern-day richness pattern of freshwater fishes in South America. To this end, we combine a reconstruction of river networks since 80 million years ago with a model simulating dispersal, allopatric speciation and extinction over the dynamic landscape of rivers and lakes. We show that Andean mountain building and consequent numerous small river capture events in western Amazonia caused freshwater habitats to be highly dynamic, leading to high diversification rates and exceptional richness. The history of marine incursions and lakes, including the Miocene Pebas megawetland system in western Amazonia, played a secondary role. This study is a major step towards the understanding of the processes involved in the interactions between the solid Earth, landscapes, and life of extraordinary biodiverse South America.
Towards Clock Ties for a Global Geodetic Observing System
Authors: Kodet Jan , Schreiber Ulrich , Klügel Thomas , Eckl Johann
Published: March 2022

Over the last two decades, the precision of individual measurements of Space Geodesy improved to a millimeter level. However, the overall achieved accuracy remains at a centimeter level due to systematic errors. The fundamental stations operating more than one space geodetic measurement technique present a keystone in systematic error investigation and mitigation. Due to regular surveys, the distances and mutual movements of the reference points are established with millimeter accuracy. The problem arises in the combination at the observation level, where the residuals of the measurements do not match with the established geometrical ties sufficiently well. Internal instrumental signal delays within each technique are causing this detrimental effect.

We have identified time coherence between the individual techniques and fundamental stations as the proper tool to overcome this problem. Within IAG Project QuGe we examine referencing the instrumentations to the optical clocks. In this scenario, the clock parameter in geodesy does not need to be adjusted any more, and all systematic effects would promote. To transfer clock stability within an entire station campus, we use a mode-locked fs-pulse laser, which is distributed using actively delay compensated fiber links, provides the necessary means to identify and remove these systematic errors. This talk illustrates some results and introduces the novel time distribution system of the Geodetic Observatory Wettzell, which realizes an ideal test bench for these clock ties.
Observed connection between blocking and sudden stratospheric warming events using GNSS radio occultation observations
Authors: Yessimbet Kamilya , Ossó Albert , Ladstädter Florian , Steiner Andrea
Published: March 2022

A better understanding of the dynamics in the upper troposphere and lower stratosphere (UTLS) is important for e.g., improving surface weather predictability. This study focuses on wave propagation in the UTLS and its role in the connection between blocking and stratospheric variability associated with sudden stratospheric warming (SSW) events.  We analyse the properties of the quasi-geostrophic Eliassen-Palm (EP) flux in the UTLS using vertically high-resolved Global Navigation Satellite System (GNSS RO) radio occultation observations.

The results show that GNSS RO observations provide detailed information on the vertical structure in the UTLS and are suitable for observing the atmospheric circulation. The EP flux obtained with the GNSS RO is in good agreement with theory and previous studies. We find that SSW is preceded by enhanced EP flux propagating upward in the UTLS, associated with blocking events. In the case of wave reflection, downward propagation leads to blocking over the North Pacific.
Recent changes in persistence over Europe and the World in reanalysis dataset
Authors: Gözlet Mehmet Sedat , Kjellsson Joakim , Savita Abhishek , Latif Mojib
Published: March 2022

The intensity and frequency of persistent heat waves and droughts have increased over the last few decades. While some of the changes may be attributed to natural variability, it is a known reality that climate change contributes to these tendencies. According to the Fifth Assessment Report of the IPCC, these anomalies are projected to be accelerated and impact humans, ecology, agricultural events, and natural systems.

Understanding the spatiotemporal structure of heat waves is crucial to deciding what environmental change will affect the above-mentioned impacts. In this study, the temporal autocorrelation of near-surface temperature and 850 hPa geopotential height from daily ERA-5 reanalysis data is examined. The focus is on the period from 1979 to 2019. To explore this 41-year long dataset, spatio-temporal trend analysis is also conducted along with autocorrelation. The trends are inspected under 3, 5, and 7-day lag autocorrelations.

In this context, the summer of 2003 shows a very high autocorrelation of geopotential height over central Europe in this analysis, which is consistent with a persistent heat wave that resulted in a death toll. Along with the yearly analyzed data, the trends are calculated both as a whole and divided into intervals. The trend analysis yields high results that cluster around Northern Africa, the Middle East, Middle China, and Middle Russia in the summer season. Furthermore, in the winter season, Siberia, Middle Africa, and the northern part of South America reflect high trends.
Mapping subsidence in Lagos, Nigeria with Sentinel-1A/B Satellite Radar
Authors: Johnson Joel , Tiampo Kristy , Heijkoop Eduard , Willis Michael , Nerem Steven
Published: March 2022

Over 10 percent of the worlds’ population lives less than 10 meters above sea level(McGranahan et al,. 2007), at risk for rising seas and sinking coasts. In addition, coastal inhabitants preferentially live in locations that are subsiding (Nicholls et al,. 2021), representing a flooding threat to people and infrastructure in coastal cities. Findings from the Intergovernmental Panel on Climate Change(IPPC) outline the risks and impacts of sea level rise on flooding and identify a knowledge gap regarding the combined effects with coastal subsidence. When drivers of subsidence combine, they can generate sinking rates of 6-100mm/yr, an order of magnitude larger than the 3-10mm/yr for sea level rise (Erkens et al., 2015). 

Access to C-band Synthetic Aperture Radar (SAR) data through the European Space Agency (ESA) Sentinel-1A/B satellites and the upcoming NASA-ISRO SAR (NISAR)  mission provides increased opportunities for differential interferometric synthetic aperture radar (DInSAR) monitoring. Here we provide results from a dockerized supercomputer workflow that rapidly generates DInSAR pairs from Sentinel-1 imagery using the JPL/Caltech/Stanford InSAR Scientific Computing Environment (ISCE)  processing software (Rosen et al., 2012) at ~10 meter resolution. Results from this workflow are used to create a time series of subsidence for Lagos, Nigeria, where rapid urban growth has led to accelerated subsidence throughout the city.
GNSS Observations of Antarctic Crustal Deformation – International Framework for Future Networks?
Authors: Wilson Terry J.
Published: March 2022

Geodetic time series from autonomous GNSS systems distributed across Antarctica are revealing unexpected patterns and startling rates of crustal deformation due to GIA.  Linked with seismic mapping and derived rheological properties of the Antarctic crust and mantle, and with new modeling capabilities, our understanding of the timescales of GIA response to ice sheet change is swiftly advancing.  Rapid GIA response allows for cryosphere-solid earth interactions that can alter ice sheet behavior on decadal and centennial timescales.  Continued progress in understanding how such feedbacks may influence future contributions of polar ice sheets to global sea level change requires continuing and expanding our geodetic observations. What frameworks can lead to implementation of this goal?  U.S. and international science vision documents pertaining to geodynamics, the changing cryosphere and sea level, all point to international collaborative efforts as the way to achieve ambitious science goals and extend observational capacities in polar regions.  SCAR research programmes facilitated the network vision and collaborative relations that led to the POLENET (POLar Earth observing NETwork) network of geophysical and geodetic instruments during the International Polar Year 2007-08. Can the SCAR INSTANT programme provide a framework for collaborative initiatives between national Antarctic programs to form a sustainable model to support acquisition of the observations required to meet community science objectives?  Let’s consider the ‘grass roots’ actions by the science community needed to push international, interdisciplinary science frameworks forward.
Some key challenges for subseasonal to decadal prediction research
Authors: Merryfield William , Baehr Johanna , Batté Lauriane , Beraki Asmerom , Hermanson Leon , Hudson Debra , Johnson Stephanie , Lee June-Yi , Massonnet François , Muñoz Ángel , Orsolini Yvan , Ren Hong-Li , Saurral Ramiro , Smith Doug , Takaya Yuhei , Raghavan Krishnan
Published: March 2022

The practice of initialized subseasonal, seasonal and decadal climate prediction has matured considerably in recent years, with real-time subseasonal and decadal multi-system ensembles joining those established previously for the seasonal to multi-seasonal range. However, substantial scientific, modelling, and informational challenges remain that must be overcome in order to more fully realize the potential for such predictions to serve societal needs. This presentation will examine five such challenges that the World Climate Research Programme’s Working Group on Subseasonal to Interdecadal Prediction (WGSIP) has identified as crucial for further advancing capabilities for translating the inherent predictability of the Earth system into actionable predictive information. Surmounting these challenges will bring nearer an envisaged future in which global users have access to such information specific to individual needs, across Earth system components and on a continuum of time scales, with degrees of confidence, limitations and uncertainties clearly indicated, as well as tools to guide optimal actions.
Real Time Data Acquisition for Mission-Critical Seismic Networks
Authors: Laporte Michael
Published: March 2022

Ensuring the reliable acquisition of real time seismic data from remote monitoring stations is an inherently challenging task. Stations are often in isolated locations with little to no supporting infrastructure, creating limitations on power and communications systems which demand design tradeoffs. When the data is driving mission-critical public safety systems, such as Earthquake Early Warning (EEW) and future work for Operational Earthquake Forecasting (OEF), real time acquisition performance is of critical importance. 

In particular for EEW, acquisition performance must be measured not only in real time data availability, but also data latency and bandwidth utilization.  Beyond these key performance metrics, it is critical that the system is robust, with layers of redundancy to ensure continued operation in the event of a damaging earthquake. A comprehensive system test and acceptance program is needed to ensure performance requirements are met and to have confidence the system will function as intended at the critical moment.

 

This study examines the objectives, the factors considered and the approaches taken in the design and implementation of a real time acquisition systems for mission-critical networks.

Authors 

Michael Laporte, Michael Perlin, Ben Tatham, Valarie Hamilton, Bruce Townsend
FAIR Data Teams: Rapid access to climate measurements by rethinking workflows
Authors: Barna Andrew , Diggs Stephen , Becker Susan
Published: March 2022

In this presentation, we will discuss the procedures and utilities employed that produced the final core data (CTDO, nutrients, salinity, and oxygen). These datasets were published within 4 weeks of the conclusion of the cruise, much quicker than the program's 6-week requirement for preliminary data, and significantly faster than the 6-month final data requirement.

The Global Ocean Ship-based Hydrographic Investigations Program (GO-SHIP) “provides approximately decadal resolution of the changes in inventories of heat, freshwater, carbon, oxygen, nutrients, and transient tracers, covering the ocean basins from coast to coast and full depth (top to bottom), with global measurements of the highest required accuracy to detect these changes.”

The Oceanographic Data Facility at Scripps Institution of Oceanography has been making the CTDO, salinity, oxygen, and nutrient measurements since the program's inception for some of the US lead GO-SHIP expeditions. This group internally shares personnel with the corresponding data repository (CCHDO). This collaboration allows the technicians to proactively develop tools and data formats that are both compliant for data submission as well as easy to utilize at sea. Mature versions of these utilities and procedures were promoted in both 1-on-1 conversations and interactive demonstrations.

The most recent set of measurements made by the US GO-SHIP program was in the Atlantic ocean last year (March-May 2021). Taking advantage of existing close collaborations within the shipboard environment, we were able to ensure measurements were documented while the expedition was still in progress, ensuring that data formats were consistent and conforming to the program's required formats. A full metadata package for the global/cross-cruise database, in addition to mature preliminary files, was ready at the conclusion of the expedition. The close relationship between the seagoing team and the data managers in the repository has allowed for the accelerated publication of finalized measurements through sharing of software, metadata databases, and expertise.
Detection of forest stress from European spruce bark beetle attack in Northern Italy through a stress classification algorithm based on NDVI temporal changes
Authors: Giomo Matteo , Moretto Johnny , Fantinato Luciano
Published: March 2022

The European spruce bark beetle (Ips typographus) is one of the most detrimental insects of the European spruce forests. An effective mitigation measure consists in the removal of infected trees before the beetles leave the bark, which generally happens before the end of June. To minimize economic loss and prevent tree destruction, fast and early detection of European spruce bark beetle is therefore crucial for the future of spruce forests.

In order to detect the forest stressed regions, possibly associated to the beetle infestation, we investigated the forest vigour changes in time. One of the most damaged regions is Northern Italy in which the beetle diffusion has highly increased after the Storm Adrian of late 2018.

In this work we used Sentinel-2 images of a study area in the mountain territory of Val di Fiemme (Trento, Italy) from early 2017 to late 2021. A preliminary field investigation was necessary to localize healthy (green) and stressed (red) trees. NDVI index trends from Sentinel-2 showed an evident vigour discrepancy from green and red regions.

We therefore conceive a classification algorithm based on the slope of fitting lines of NDVI over time. Model accuracy is around 86%. The result is a classified map useful to distinguish stressed and healthy forest areas.

By using the proposed method and Google Earth Engine computational capabilities, we highlight the potential of a simple and effective model to predict and detect forest stressed areas, potentially associated with the diffusion of the European spruce bark beetle.
A hybrid modelling approach to debris flow modelling combining physical and numerical simulations
Authors: Hansen Bendik , Pummer Elena , Sigtryggsdóttir Fjóla , Kowalski Julia , Zhao Hu
Published: March 2022

Debris flows pose a significant threat to human life and infrastructure due to the extreme forces they bring into play. In order to prevent and mitigate the effect of such events, a fundamental understanding of processes related to debris flows is required. To this end, we used a hybrid modelling approach combining physical and numerical modelling to simulate debris flows

The physical model that served as the basis for the numerical one was a seesaw-like plexiglass flume with a hinge in the middle and sediment reservoirs at the two extreme ends. The hinge enabled the movement of the debris flow back and forth between the reservoirs when the flume was tipped, thus providing reproducible initial (sediment composition) and boundary (slope, roughness) conditions for each run. The physical model was 0.3 m wide and 4 m long, in addition to 0.5 m at each end (lengthwise) working as sediment reservoirs.  Velocity and flow height data were recorded at four points along the flume.

We used the mass flow modelling software r.avaflow to reproduce the physical model runs with varying slopes (20, 25, and 30 degrees) and solid contents (40, 50, and 60 %). The model included simulations with both multiphase flow (unique processes for solids and fluids) and a Voellmy-type mixture model (mass represented as one homogenous block). The present study shows the preliminary findings of the research, but the long-term goal is to utilize a hybrid modelling approach to combine the advantages of real data from physical modelling with the increased potential for data extraction and number of model runs that we get from numerical modelling to perform detailed sensitivity and uncertainty analyses with probabilistic simulations in future work.
Storm characteristics and extreme sub-daily precipitation statistics over CONUS
Authors: Araujo Diogo , Marra Francesco , Ali Haider , Fowler Hayley , Nikolopoulos Efthymios
Published: March 2022

The analysis of short-duration precipitation extremes is of foremost importance as heavy precipitation is directly related to many hazards, e.g. flash floods, landslides and crop damage. Here, we adopt an extreme value framework based on the concept of ordinary events, defined as independent realizations of the process of interest. In particular, we aim at investigating the link between the characteristics of ordinary storms (e.g. seasonality, average duration, autocorrelation) and the statistics of the emerging extremes at sub-daily durations (1-24 h). We used the Global Sub-Daily Rainfall (GSDR) dataset, which provides quality controlled hourly precipitation data from rain gauges over the Contiguous United States (CONUS). 

First, we tested the hypothesis that a Weibull distribution can describe the tail of ordinary events and independently reproduce the annual maxima. Then, we quantified the portion of ordinary events, termed tail hereinafter, which share the statistical properties with annual maxima. Analysis of the storm characteristics show shorter average duration storms (< 12h) in the central portion of CONUS, between latitudes 90ºW and 105ºW. Seasonality analysis showed predominance of summer events in all central and eastern areas, with exception to a region encompassing the northwestern areas of the southern US states, which are dominated by spring events. On the western coast, winter events dominate the tail of the distribution of the ordinary events. The majority of these events happened in the afternoon (12PM to 6PM) or night (6PM to 12AM). The parameters describing our extreme value distribution revealed insightful features. The scale parameter of the Weibull distribution describing the tail followed the local climatology, with higher values over the southeast of CONUS (region characterized for high intensity precipitation), and small values over the northwest. The shape parameter indicates heavier-tailed distributions on the north and central regions of the US, as opposed to the majority of stations CONUS-wide. On average, the number of events per year is larger in the east (50 to 100 events per year) when compared to the west (0 to 50 events per year) . 

Further analyses include investigating the influence of storm properties in the parameters of our extreme value distribution. This link, if proven significant, can be used to establish predictors for extreme precipitation statistics that stem from characteristics of ordinary storm events.