bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Epidemiology of Extreme Weather Event Disasters (1969-2018)
Authors: Keim Mark E. 
Published: April 2020

AbstractIntroduction:This manuscript summarizes the global incidence, exposures, mortality, and morbidity associated with extreme weather event (EWE) disasters over the past 50 years (1969-2018).Methods:A historical database (1969-2018) was created from the Emergency Events Database (EM-DAT) to include all disasters caused by seven EWE hazards (ie, cyclones, droughts, floods, heatwaves, landslides, cold weather, and storms). The annual incidence of EWE hazards and rates of exposure, morbidity, and mortality were calculated. Regression analysis and analysis of variance (ANOVA) calculations were performed to evaluate the association between the exposure rate and the hazard incidence rate, as well as the association between morbidity and mortality incidence rates and rates of human exposure and annual EWE incidence.Results:From 1969-2018, 10,009 EWE disasters caused 2,037,415 deaths and 3,998,466 cases of disease. A reported 7,350,276,440 persons required immediate assistance. Floods and storms were the most common. Most (89%) of EWE-related disaster mortality was caused by storms, droughts, and floods. Nearly all (96%) of EWE-related disaster morbidity was caused by cold weather, floods, and storms. Regression analysis revealed strong evidence (R2 = 0.88) that the annual incidence of EWE disasters is increasing world-wide, and ANOVA calculations identified an association between human exposure rates and hazard incidence (P value = .01). No significant trends were noted for rates of exposure, morbidity, or mortality.Conclusions:The annual incidence of EWEs appears to be increasing. The incidence of EWEs also appears to be associated with rates of human exposure. However, there is insufficient evidence of an associated increase in health risk or human exposures to EWEs over time.
Anthropocene Geomorphic Change. Climate or Human Activities?
Authors: Cendrero Antonio , Forte Luis M. , Remondo Juan , Cuesta‐Albertos Juan A. 
Published: April 2020

Key PointsSedimentation rates and frequency of geomorphic disasters show a marked increase worldwide, especially after midtwentieth centuryThis points to an intensification of geomorphic processes, which could be one of the characteristics of the AnthropoceneLand surface change caused by human activities, rather than climate change, is very likely behind the intensification of geomorphic processes
Long‐Term Trajectory of Nitrogen Loading and Delivery From Mississippi River Basin to the Gulf of Mexico
Authors: Tian Hanqin , Xu Rongting , Pan Shufen , Yao Yuanzhi , Bian Zihao , Cai Wei‐Jun , Hopkinson Charles S. , Justic Dubravko , Lohrenz Steven , Lu Chaoqun , Ren Wei , Yang Jia 
Published: April 2020

AbstractThe large areal extent of hypoxia in the northern Gulf of Mexico has been partially attributed to substantial nitrogen (N) loading from the Mississippi River basin, which is driven by multiple natural and human factors. The available water quality monitoring data and most of the current models are insufficient to fully quantify N load magnitude and the underlying controls. Here we use a process‐based Dynamic Land Ecosystem Model to examine how multiple factors (synthetic N fertilizer, atmospheric N deposition, land use changes, climate variability, and increasing atmospheric CO2) have affected the loading and delivery of total nitrogen (TN) consisting of ammonium and nitrate (dissolved inorganic N) and total organic nitrogen from the Mississippi River basin during 1901–2014. The model results indicate that TN export during 2000–2014 was twofold larger than that in the first decade of twentieth century: Dissolved inorganic N export increased by 140% dominated by nitrate; total organic nitrogen export increased by 53%. The substantial enrichment of TN export since the 1960s was strongly associated with increased anthropogenic N inputs (synthetic N fertilizer and atmospheric N deposition). The greatest export of TN was in the spring. Although the implementation of N reduction has been carried out over the past three decades, total N loads to the northern Gulf of Mexico have not decreased significantly. Due to the legacy effect from historical N accumulation in soils and riverbeds, a larger reduction in synthetic N fertilizer inputs as well as improved N management practices are needed to alleviate ocean hypoxia in the northern Gulf of Mexico.
Bayesian Inversion of Wrapped Satellite Interferometric Phase to Estimate Fault and Volcano Surface Ground Deformation Models
Authors: Jiang Yu , González Pablo J. 
Published: April 2020

AbstractBayesian inference and an improved downsampling method is used to determine earthquake and volcano source parameters using a popular geodetic observation method, satellite radar interferometry. The main novelty of the proposed approach is that the interferometric wrapped phase can be directly inverted, circumventing the ill‐posed phase unwrapping processing step. Phase unwrapping errors severely affect the estimation of earthquake and volcano source parameters using interferometric observations. Therefore, it is desirable to avoid phase unwrapping completely. To overcome the need for phase unwrapping, we propose a downsampling algorithm and a method to estimate the covariance function of the wrapped phase and establish an appropriate misfit function between the observed and simulated wrapped phase. Uncertainties in source parameters are assessed with a Bayesian approach, and finally, the robustness of the inversion methodology is tested in multiple simulations including variable decorrelation and atmospheric noise simulations. The method is shown to be robust in challenging noise scenarios. It features an improvement in performance with the Bayesian approach, compared to similar previous methods, avoiding any influence of seed starting models and escaping local minima. The impact of a small percentage of incorrectly unwrapped phase observations in current state‐of‐the‐art methods is shown to strongly affect the estimation process. We conclude that in the cases where phase unwrapping is difficult or even impossible, the proposed inversion methodology with wrapped phase will provide an alternative approach to assess earthquake and volcano source model parameters.
Simulations of Tephra Fall Deposits From a Bending Eruption Plume and the Optimum Model for Particle Release
Authors: Mannen Kazutaka , Hasenaka Toshiaki , Higuchi Atsushi , Kiyosugi Koji , Miyabuchi Yasuo 
Published: April 2020

AbstractWe developed a simulation code named WT, which calculates tephra fallout from eruption plumes bent by wind. This proposed model assumes a series of radial particle sources arraying along the theoretically predicted trajectory of the plume center. To validate WT, we reconstructed the tephra dispersal during the 2011 sub‐Plinian eruption of Shinmoedake in Japan. This eruption was ideal for the validation because it was observed through various approaches; however, high‐resolution data of the fluctuating plume height made it difficult to determine a representative eruption time and plume height for running the simulations. Also, the amount of particle segregation along the plume could not be determined a priori. We thus implemented inversion calculations to study the optimum particle segregation pattern for possible ranges of time and the plume height, and the misfit between the observed and calculated mass loadings on the ground was evaluated. After this process and the following analysis, the optimum eruption time was determined for one of three major explosions (18:00 Japan Standard Time on 26 January). The optimum plume height was estimated to be 4 km above sea level, slightly lower than the estimation derived by the weather satellite (5 km). When wind shear exists, the WT model has a significant advantage in reconstructing tephra dispersal over the classical code named Tephra2, the prototype of WT. The WT inversion implies a simple segregation model from a well‐mixed plume, and further studies on particle segregation patterns will help to improve the accuracy of forward WT simulations.
Using SF6 and Xe to Monitor Gas Migration Through Explosion‐Generated Fracture Networks
Authors: Stroujkova A. , Gorman E. , Avendaño S. T. , Horne M. , Person M. A. , Hubbard P. , Salerno J. , Carrigan C. R. , Harp D. R. , Stauffer P. H. 
Published: April 2020

AbstractWe describe a field study where tracer gas was injected into a subsurface cavity created by a small chemical explosion beneath the water table. The main objective of the study is to compare the migration of sulfur hexafluoride (SF6) and xenon (Xe) through an explosion‐generated fracture network and to study the influence of ground water on gas transport. A mixture of tracer gases (50% of SF6 and 50% of Xe) was injected on 31 October 2018 and gas sampling continued until 8 November 2018. We observe similar trends in SF6 and Xe concentrations at four ground surface sampling sites. The changes in the SF6/Xe ratios with time show that more SF6 than Xe is observed during the barometric pressure lows when the absolute measured concentrations are highest. Conversely, the ratio SF6/Xe is less than 1 during the high‐pressure intervals when absolute measured concentrations are low. The results of the experiment suggest that during barometric pressure lows the tracer is migrating to the surface primarily by advective gas phase transport, whereas during barometric pressure highs, advection is suppressed and near‐surface evaporation of interstitial pore fluid with tracer dissolved in it becomes more important. Thus, the results of the experiment show that the gas concentrations at the surface are controlled by the combined effects of the gas dissolution into pore water and the barometric pressure fluctuations.
Methods for Rapidly Estimating Velocity Precision from GNSS Time Series in the Presence of Temporal Correlation: A New Method and Comparison of Existing Methods
Authors: Langbein John 
Published: April 2020

AbstractTime series of position estimates from Global Navigational Satellite System (GNSS) are used to measure the velocities of points on the surface of the Earth. Along with the velocity estimates, a measure of the precision is needed to assess the quality of the velocity measurement. Here, I evaluate rate uncertainties provided by four different methods that have been applied to geodetic time series. The most rigorous approach uses a data covariance that incorporates a variety of noise processes relevant to geodetic time series but is computationally demanding. Two other approaches are efficient algorithms and are used widely, but both can provide less rigorous estimates of the rate uncertainty. I propose and evaluate a fourth method, which provides estimates of rate uncertainty closer to the rigorous approach but is significantly less computationally demanding. I have evaluated all three methods against the more rigorous method using both simulations and time series from 190 GNSS sites. For data best characterized as having a flicker type noise process, one of the widely used methods overestimates the uncertainty by up to a factor of 2, while the other widely used method underestimates the uncertainty by less than a factor of 2. For a random‐walk process, both methods underestimate the rate uncertainty by a factor of 3 to 5.
A Century of Southern California Coastal Ocean Temperature Measurements
Authors: Rasmussen Linda L. , Carter Melissa L. , Flick Reinhard E. , Hilbern Mary , Fumo James T. , Cornuelle Bruce D. , Gordon Bonnie K. , Bargatze Lee F. , Gordon R. Lee , McGowan John A. 
Published: April 2020

AbstractScripps Institution of Oceanography Pier has been the site of daily temperature measurements since the original structure was built in 1916. The time series is the longest continuous record of temperature on the Pacific Rim and is frequently cited as an indicator of ocean temperature trends in the region. The over 100‐year long record of daily surface temperature and slightly shorter bottom temperature data are presented here, with adjustment for bias owing to changes in sampling time of day. Data were generally collected near 8:00 a.m. in the early years, when water temperatures are cooler, and gradually shifted later in the day, when temperatures are warmer. In addition, cold surges from irregular internal tidal bores complicated attempts to estimate daily heating‐cooling cycles solely as a function of time of day. To isolate the effect of the solar heating cycle, adjustments were calculated based on seasonally variable diurnal solar heating using a surface ocean heating model and locally measured insolation data. Although the observed warming trends in nearshore temperatures are reduced by about 0.2 °C per century in the adjusted data, they still retain a significant increase of 1.24 °C per century at the surface and 1.67 °C per century in bottom waters.
Winter Arctic Sea Ice Thickness From ICESat‐2 Freeboards
Authors: Petty Alek A. , Kurtz Nathan T. , Kwok Ron , Markus Thorsten , Neumann Thomas A. 
Published: April 2020

AbstractNational Aeronautics and Space Administration's (NASA's) Ice, Cloud, and land Elevation Satellite‐2 (ICESat‐2) mission was launched in September 2018 with the primary goal of monitoring our rapidly changing polar regions. The sole instrument onboard, the Advanced Topographic Laser Altimeter System, is now providing routine, very high‐resolution, surface elevation data across the globe, including the Arctic and Southern oceans. In this study, we demonstrate our new processing chain for converting the along‐track ICESat‐2 sea ice freeboard product (ATL10) into sea ice thickness, focusing our initial efforts on the Arctic Ocean. For this conversion, we primarily make use of snow depth and density data from the NASA Eulerian Snow on Sea Ice Model. The coarse resolution (~100 km) snow data are redistributed onto the high‐resolution (approximately 30–100 m) ATL10 freeboards using relationships obtained from snow depth and freeboard data collected by NASA's Operation IceBridge mission. We present regional sea ice thickness distributions and highlight their seasonal evolution through our first winter season of data collection. We include ice thickness uncertainty estimates, while also acknowledging the limitations of these estimates. We generate a gridded monthly thickness product and compare this with various monthly sea ice thickness estimates obtained from European Space Agency's CryoSat‐2 satellite mission, with ICESat‐2 showing consistently lower thicknesses. Finally, we compare our February/March 2019 thickness estimates to ICESat February/March (19 February to 21 March) 2008 ice thickness estimates using the same input assumptions, which show an ~0.37 m or ~20% thinning across an inner Arctic Ocean domain in this 11‐year time period.
Modeling Spatial Heterogeneity in Surface Turbulent Heat Flux in the U.S. Southern Great Plains
Authors: Williams Ian N. , Lee Jungmin M. , Tadić Jovan , Zhang Yunyan , Chu Housen 
Published: April 2020

AbstractAdvances in numerical modeling of cloud dynamics are driving a need for improved land model prediction at convective storm scales. In this study, satellite and ground‐based vegetation remote sensing data were combined with land model experiments to more accurately characterize land surface spatial heterogeneity in the Community Land Model (CLM4.0). The new subgrid classification of plant functional types (PFT) and leaf area index (LAI) enables consistent comparison between models and ground‐based flux measurements in the U.S. southern Great Plains. Errors in vegetation data sets (inferred from comparison between 250 m satellite and ground‐based LAI), while large, had less impact on the simulated characteristics of spatial heterogeneity compared to errors in model representation of surface energy partitioning (between latent and sensible heat flux) and its relationship to LAI. Predicted spatial heterogeneity in surface energy partitioning was enhanced after replacing soil and stomatal resistance parameters with a new set that better predicts the observed relationship to LAI. These modifications increase the number of smaller (mesoscale) dry land patches having higher sensible heat flux. The parameter experiments suggest that vegetation state and processes (transpiration) act to broaden the size spectrum of surface heat flux heterogeneity, which can influence clouds and convective initiation. Moreover, improvements in vegetation input data and model parameters had partially compensating effects on surface flux heterogeneity, indicating the importance of evaluating input data and parameterizations together to improve prediction at higher spatial resolutions.
The Provenance of Regolith at the Chang'e‐5 Candidate Landing Region
Authors: Xie Minggang , Xiao Zhiyong , Zhang Xunyu , Xu Aoao 
Published: April 2020

AbstractThe upcoming lunar Chang'e‐5 mission is scheduled to land near Mons Rümker, in northern Oceanus Procellarum, and return samples with masses up to 2 kg from depths up to ~2 m. A clear understanding of the regolith components in the candidate landing region is crucial to both the selection of sampling sites and the interpretation of the geological affinities for the returned samples. We quantitatively estimate the abundance of distantly sourced particles (DSPs) in the regolith at the landing region using an updated ballistic sedimentation model. Our results suggest that older units have a higher abundance of DSPs. In the targeted landing area, the total abundance of DSPs on the surface of the regolith varies from approximately 12% to 20%, and most of the DSPs on the surface are ejecta from the Pythagoras (~5%) and/or Aristarchus (~7%) craters. The youngest geological unit, which is located in the easternmost sector of the landing region, possesses the least DSPs in the regolith. Therefore, sampling the eastern unit has a higher potential of revealing both the petrological characteristics and age of the youngest mare basalt, which are fundamentally important to improve both the lunar crater chronology and the understanding of late‐stage evolution of the Moon. Our results also indicate that the anorthositic material within the shallow regolith is most likely ejected from the Pythagoras and Aristarchus craters, which could further improve the understanding of lunar geology and chronology.
On‐Deck Seismology: Lessons from InSight for Future Planetary Seismology
Authors: Panning M. P. , Pike W. T. , Lognonné P. , Banerdt W. B. , Murdoch N. , Banfield D. , Charalambous C. , Kedar S. , Lorenz R. D. , Marusiak A. G. , McClean J. B. , Nunn C. , Stähler S. C. , Stott A. E. , Warren T. 
Published: April 2020

AbstractBefore deploying to the surface of Mars, the short‐period (SP) seismometer of the InSight mission operated on deck for a total of 48 hr. This data set can be used to understand how deck‐mounted seismometers can be used in future landed missions to Mars, Europa, and other planetary bodies. While operating on deck, the SP seismometer showed signals comparable to the Viking‐2 seismometer near 3 Hz where the sensitivity of the Viking instrument peaked. Wind sensitivity showed similar patterns to the Viking instrument, although amplitudes on InSight were ∼80% larger for a given wind velocity. However, during the low‐wind evening hours, the instrument noise levels at frequencies between 0.1 and 1 Hz were comparable to quiet stations on Earth, although deployment to the surface below the Wind and Thermal Shield lowered installation noise by roughly 40 dB in acceleration power. With the observed noise levels and estimated seismicity rates for Mars, detection probability for quakes for a deck‐mounted instrument is low enough that up to years of on‐deck recordings may be necessary to observe an event. Because the noise is dominated by wind acting on the lander, though, deck‐mounted seismometers may be more practical for deployment on airless bodies, and it is important to evaluate the seismicity of the target body and the specific design of the lander. Detection probabilities for operation on Europa reach over 99% for some proposed seismicity models for a similar duration of operation if noise levels are comparable to low‐wind time periods on Mars.
Stratospheric Injection of Massive Smoke Plume From Canadian Boreal Fires in 2017 as Seen by DSCOVR‐EPIC, CALIOP, and OMPS‐LP Observations
Authors: Torres O. , Bhartia P. K. , Taha G. , Jethva H. , Das S. , Colarco P. , Krotkov N. , Omar A. , Ahn C. 
Published: April 2020

AbstractA carbonaceous aerosol plume associated with wildfires in British Columbia in August 2017 reached the stratosphere a few days following the fires onset. The Earth Polychromatic Imaging Camera (EPIC) sensor onboard the Deep Space Climate Observatory (DSCOVR) satellite observed the spatial and temporal evolution of the plume for about 6 weeks. EPIC's near‐hourly observations of the Earth's sunlit disk allowed for monitoring the smoke plume several times per day. High ultraviolet aerosol index values pointed to the presence of an aerosol layer in the upper troposphere and lower stratosphere, confirmed with Cloud‐Aerosol Lidar with Orthogonal Polarization (CALIOP) lidar observations. EPIC aerosol optical depth retrievals and CALIOP information on layer height were used to estimate the stratospheric portion of the aerosol mass, reaching a maximum of 268 ± 86 Kt 3 days after the onset of the wildfires. About 10% of this aerosol mass reached the stratosphere on 13 August, whereas the remaining 90% did so over the following 2 days. Observed daytime and inferred nighttime rates of stratospheric aerosol mass increase showed a more rapid daytime increase, consistent with variability in diurnal insolation, suggesting that solar radiation driven processes may have contributed to the observed stratospheric aerosol mass increase. Global modeling results support the possible role of diabatic aerosol self‐lofting. Ozone Mapping and Profiler Suite Limb Profiler (OMPS‐LP) aerosol retrievals showed the spread of stratospheric aerosols in the Northern Hemisphere, reaching peak concentration between October 2017 and January 2018, when about half the Northern Hemisphere experienced a detectable enhancement of stratospheric aerosols with respect to preinjection conditions. The lifetime and aerosol mass of this smoke event were comparable to those of a moderate volcanic eruption.