bluuebunny/crossref_metadata_2025_split huggingface dataset:
Future scenarios for earthquake and flood risk in Eastern Europe and Central Asia
Authors: Murnane R. J. , Daniell J. E. , Schäfer A. M. , Ward P. J. , Winsemius H. C. , Simpson A. , Tijssen A. , Toro J. 
Published: June 2017

AbstractWe report on a regional flood and earthquake risk assessment for 33 countries in Eastern Europe and Central Asia. Flood and earthquake risk were defined in terms of affected population and affected gross domestic product (GDP). Earthquake risk was also quantified in terms of fatalities and capital loss. Estimates of future population and GDP affected by earthquakes vary significantly among five shared socioeconomic pathways that are used to represent population and GDP in 2030 and 2080. There is a linear relationship between the future relative change in a nation's exposure (population or GDP) and its future relative change in annual average population or GDP affected by earthquakes. The evolution of flood hazard was quantified using a flood model with boundary conditions derived from five different general circulation models and two representative concentration pathways, and changes in population and GDP were quantified using two shared socioeconomic pathways. There is a nonlinear relationship between the future relative change in a nation's exposure (population or GDP) and its future relative change in its annual average population or GDP affected by floods. Six regions can be defined for positive and negative relative change in population that designate whether climate change can temper, counter, or reinforce relative changes in flood risk produced by changes in population or exposure. The departure from the one‐to‐one relationship between a relative change in a nation's population or GDP and its relative change in flood risk could be used to inform further efforts at flood mitigation and adaptation.
Foreshock wave interaction with the magnetopause: Signatures of mode conversion
Authors: Shi Feng , Cheng Lei , Lin Yu , Wang Xueyi 
Published: June 2017

AbstractOur previous hybrid simulation (Shi et al., 2013) under a radial interplanetary magnetic field (IMF) and a supercritical solar wind Mach number has shown that foreshock compressional waves originated from the quasi‐parallel (Q‐∥) shock are mode converted to kinetic Alfvén waves (KAWs) at the Alfvén resonance surface of the subsolar magnetopause. In this paper, three‐dimensional global dayside mode conversion is investigated for cases under various solar wind conditions using the global hybrid model. The global patterns and propagations of KAWs are distinguished and presented. Under a near‐critical Mach number (MA=3), KAW structures due to mode conversion exhibit a feature of broader excitation regions in the magnetopause boundary layer (MPBL) compared to supercritical Mach number (MA=5) shocks. For cases with an oblique IMF with supercritical Mach numbers (MA=5), the amplitude of magnetosheath compressional waves is larger at the quasi‐parallel shock (Q‐∥) than at the quasi‐perpendicular (Q‐⊥) shock. Downstream of the Q‐∥ shock, there is a general trend that the perturbations of density (N) and magnetic field (B) change from predominantly in‐phase in the magnetosheath to antiphase near the MPBL. While downstream of the Q‐⊥ shock, an antiphase relation between N and B is dominant throughout the magnetosheath and magnetopause except near the shock transition. The compressional drivers are found to reach an extended region of the magnetopause due to the combined effects of wave propagation in the plasma frame and flow convection, leading to a broad region of mode conversion at the magnetopause. Subsequently, the resulting KAWs can be carried to the regions downstream of the Q‐⊥ shock owing to the flow convection at the magnetopause. The KAWs propagate poleward along the geomagnetic field lines and meanwhile are carried tailward by the ambient flows, and they are more intense in the downstream of Q‐∥ shocks than downstream of Q‐⊥ shocks.
Three‐dimensional pathways of water masses in the South China Sea: A modeling study
Authors: Liu Zhiqiang , Gan Jianping 
Published: June 2017

AbstractWe conduct a numerical Eulerian analysis on the Lagrangian characteristics of South China Sea (SCS) water masses. This is the first study to investigate the water pathway and residence time in response to time‐dependent, three‐dimensional basin circulation in the SCS. The circulation of the SCS is largely determined by westward intrusions of the northwestern Pacific waters in the upper layer (0–750 m) and deep layer (>1500 m), and by an eastward extrusion in the intermediate layer (750–1500 m) through Luzon Strait (LS). The waters in these three layers are interlinked to sustain the three‐dimensional circulation in the SCS. The upper intrusive waters flow cyclonically and have a residence time of ∼3 years before they subduct into a deeper layer or exit the SCS through surrounding straits. The intrusive denser waters in the deep layer flow along the northern slope and reside for ∼25 years in the northern basin (north of 13°N), where a strong subduction occurs. A cyclonic circulation exists in the deep layer in the southern basin (south of 13°N), where a subduction of intermediate waters occurs over its eastern side and a deep upwelling exists over its western side. The water in the deep southern basin has a residence time of ∼40 years. The upwelled deep waters and the subducted waters from the upper layer form the intermediate water, where waters circulate anti‐cyclonically toward LS and have a longest residence time (∼42 years). These findings are supported by the spatial variation in the observed potential density variance.
On the relative importance of radiative and dynamical heating for tropical tropopause temperatures
Authors: Birner Thomas , Charlesworth Edward J. 
Published: June 2017

AbstractThe tropical tropopause layer (TTL) shows a curious stratification structure: temperature continues to decrease beyond the level of main convective outflow (∼200 hPa) up to the cold point tropopause (∼100 hPa), but the TTL is more stably stratified than the upper troposphere. A cold point tropopause well separated from the level of main convective outflow has previously been shown to be consistent with the detailed radiative balance in the TTL even without dynamical effects. However, the TTL is also controlled by adiabatic cooling due to large‐scale upwelling within the Brewer‐Dobson circulation, which creates the extremely low stratospheric water vapor content via freeze drying. Here we study the role of water vapor and ozone radiative heating on the detailed temperature structure of the TTL based on idealized single‐column radiative‐convective equilibrium simulations. An atmosphere without adiabatic cooling due to upwelling results in much higher stratospheric water vapor content; the resulting altered radiative heating structure is shown to push the TTL in a regime of radiative control by water vapor. The TTL structure is furthermore shown to be strongly sensitive to the altitude where ozone sharply transitions from tropospheric to stratospheric values. Adiabatic cooling due to upwelling is found to reduce the radiative control by water vapor, resulting primarily in a negative transport‐radiation feedback. Conversely, the radiative control by ozone is enhanced due to upwelling—a positive transport‐radiation feedback. The particularly strong ozone radiative effect may explain about half of the reported spread in cold point temperatures (∼10 K) in current climate models.
Reduced ENSO variability at the LGM revealed by an isotope‐enabled Earth system model
Authors: Zhu Jiang , Liu Zhengyu , Brady Esther , Otto‐Bliesner Bette , Zhang Jiaxu , Noone David , Tomas Robert , Nusbaumer Jesse , Wong Tony , Jahn Alexandra , Tabor Clay 
Published: June 2017

AbstractStudying the El Niño–Southern Oscillation (ENSO) in the past can help us better understand its dynamics and improve its future projections. However, both paleoclimate reconstructions and model simulations of ENSO strength at the Last Glacial Maximum (LGM; 21 ka B.P.) have led to contradicting results. Here we perform model simulations using the recently developed water isotope‐enabled Community Earth System Model (iCESM). For the first time, model‐simulated oxygen isotopes are directly compared with those from ENSO reconstructions using the individual foraminifera analysis (IFA). We find that the LGM ENSO is most likely weaker comparing with the preindustrial. The iCESM suggests that total variance of the IFA records may only reflect changes in the annual cycle instead of ENSO variability as previously assumed. Furthermore, the interpretation of subsurface IFA records can be substantially complicated by the habitat depth of thermocline‐dwelling foraminifera and their vertical migration with a temporally varying thermocline.
El Niño–Southern Oscillation‐time scale covariation of sea surface salinity and freshwater flux in the western tropical and northern subtropical Pacific
Authors: Nagano Akira , Hasegawa Takuya , Ueki Iwao , Ando Kentaro 
Published: June 2017

AbstractWe examined the covariation of sea surface salinity (SSS) and freshwater flux in the western tropical and northern subtropical Pacific on the El Niño–Southern Oscillation time scale, using a canonical correlation analysis of monthly data between 2001 and 2013. The dominant covariation, i.e., the first canonical mode, has large positive and negative amplitudes in regions east of the Philippines and New Guinea, respectively, and reaches peaks in autumn to winter of El Niño years. The positive SSS anomaly east of the Philippines is advected to the Kuroshio Extension region. We found that the second canonical mode is another coupled variation with localized amplitudes of SSS under the atmospheric convergence zones in winter to spring of La Niña years. However, the negative SSS anomaly is annihilated possibly by the evaporation in the subtropical region.
Long‐term (2005–2014) trends in formaldehyde (HCHO) columns across North America as seen by the OMI satellite instrument: Evidence of changing emissions of volatile organic compounds
Authors: Zhu Lei , Mickley Loretta J. , Jacob Daniel J. , Marais Eloïse A. , Sheng Jianxiong , Hu Lu , Abad Gonzalo González , Chance Kelly 
Published: June 2017

AbstractSatellite observations of formaldehyde (HCHO) columns provide top‐down information on emissions of highly reactive volatile organic compounds (VOCs). We examine the long‐term trends in HCHO columns observed by the Ozone Monitoring Instrument from 2005 to 2014 across North America. Biogenic isoprene is the dominant source of HCHO, and its emission has a large temperature dependence. After correcting for this dependence, we find a general pattern of increases in much of North America but decreases in the southeastern U.S. Over the Houston‐Galveston‐Brazoria industrial area, HCHO columns decreased by 2.2% a−1 from 2005 to 2014, consistent with trends in emissions of anthropogenic VOCs. Over the Cold Lake Oil Sands in the southern Alberta in Canada, HCHO columns increased by 3.8% a−1, consistent with the increase in crude oil production there. HCHO variability in the northwestern U.S. and Midwest could be related to afforestation and corn silage production. Although NOx levels can affect the HCHO yield from isoprene oxidation, we find that decreases in anthropogenic NOx emissions made only a small contribution to the observed HCHO trends.
Large biogenic contribution to boundary layer O3‐CO regression slope in summer
Authors: Cheng Ye , Wang Yuhang , Zhang Yuzhong , Chen Gao , Crawford James H. , Kleb Mary M. , Diskin Glenn S. , Weinheimer Andrew J. 
Published: June 2017

AbstractStrong correlation between O3 and CO was observed during the Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER‐AQ) aircraft experiment in July 2011 over the Washington‐Baltimore area. The observed correlation does not vary significantly with time or altitude in the boundary layer. The observations are simulated well by a regional chemical transport model. We analyze the model results to understand the factors contributing to the observed O3‐CO regression slope, which has been used in past studies to estimate the anthropogenic O3 production amount. We trace separately four different CO sources: primary anthropogenic emissions, oxidation of anthropogenic volatile organic compounds, oxidation of biogenic isoprene, and transport from the lateral and upper model boundaries. Modeling analysis suggests that the contribution from biogenic isoprene oxidation to the observed O3‐CO regression slope is as large as that from primary anthropogenic CO emissions. As a result of decrease of anthropogenic primary CO emissions during the past decades, biogenic CO from oxidation of isoprene is increasingly important. Consequently, observed and simulated O3‐CO regression slopes can no longer be used directly with an anthropogenic CO emission inventory to quantify anthropogenic O3 production over the United States. The consistent enhancement of O3 relative to CO observed in the boundary layer, as indicated by the O3‐CO regression slope, provides a useful constraint on model photochemistry and emissions.
Erosion and refilling of the plasmasphere during a geomagnetic storm modeled by a neural network
Authors: Chu X. N. , Bortnik J. , Li W. , Ma Q. , Angelopoulos V. , Thorne R. M. 
Published: June 2017

AbstractWe present a history‐dependent model of the equatorial plasma density of the inner magnetosphere using a feedforward neural network with two hidden layers. As the model inputs, we take locations and time series of SYM‐H, AL, and F10.7 indices. By considering not only the instantaneous values but also the past values of geomagnetic and solar indices, the model is history dependent on levels of geomagnetic and solar activity. The modeled electron density is continuous both spatially and temporally so that the evolution of the density can be studied (such as plasmaspheric refilling). The model is trained using the electron density inferred from the spacecraft potential from three THEMIS probes. The equatorial electron density is shown to be accurately reconstructed with a correlation coefficient of r ~ 0.953 between data and model target. Since the model is history dependent, it succeeds in reconstructing various density features and dynamic behaviors, such as the quiet time plasmasphere, erosion and recovery of the plasmasphere, as well as the plume formation during a storm on 4 February 2011. Our model may provide unprecedented insight into the behavior of the equatorial density at any time and location; as an example we show the inferred refilling rate from our model and compare it to previous estimates.
Lunar tides in total electron content over Brazil
Authors: Paulino A. R. , Lima L. M. , Almeida S. L. , Batista P. P. , Batista I. S. , Paulino I. , Takahashi H. , Wrasse C. M. 
Published: June 2017

AbstractUsing data from Global Navigation Satellite Systems dual frequency receivers, the lunar tides were studied in the ionospheric total electron content (TEC) over Brazil from 2011 to 2014. In order to calculate the amplitudes and phases of the lunar tides, quiet magnetic days within a 27 day (window) have been used to remove the solar rotation effects. Relative residuals TEC were calculated by performing a spectral analysis by removing the solar tide contributions. Lastly, a lunar month size window was used to calculate the amplitude and phase of the lunar components. Lunar diurnal tide amplitudes showed a semiannual variation with maximum in the equinox months for almost all latitudes, while lunar semidiurnal amplitudes were larger in December and January and may be related to sudden stratospheric warming events. Both components did not display significant longitudinal variation what could be due to the short range of longitude (30°). Lunar diurnal amplitudes were basically uniform over Brazil, while lunar semidiurnal amplitudes showed some peaks over the equatorial ionization anomaly crest and minimum values near the magnetic equator.
The nonlinear interactions between O+ ions and oxygen band EMIC waves
Authors: Wang Zhiqiang , Pan Zhirui , Zhai Hao , Gao Zhuxiu , Sun Kang , Zhang Yusheng 
Published: June 2017

AbstractDuring geomagnetically active times, O+ ions from the ionosphere become an important ion component in the ring current, which changes the dispersion relations and significantly enlarges the growth rate of oxygen band electromagnetic ion cyclotron (EMIC) waves. Motivated by a large number of oxygen band EMIC wave observations in the inner magnetosphere, we study the nonlinear motions of ring current O+ ions caused by the cyclotron resonance with oxygen band EMIC waves. A dimensionless parameter R is used to characterize the competition between wave‐induced and adiabatic motions. The numerical calculations based on gyroaveraged test particle equations are performed. For typical 20 keV O+ ions at L = 5, two kinds of nonlinear processes occur simultaneously when αeq > 59° (R < 2.16): the phase trapping and phase bunching. The phase trapping tends to transport the O+ ions away from the loss cone and reduce the overall loss rate estimated from the quasi‐linear theory. Instead, phase bunching tends to increase the overall loss rate. The phase‐trapped O+ ions have chance to be accelerated drastically, reaching 750% of the initial energy. These O+ ions move forward and backward alternatively along the field lines when they are bouncing back to the equator, forming a periodic energy variation which has not been reported before. The results suggest that the oxygen band EMIC waves, which appear frequently during storms, should be considered in the ring current dynamics in terms of nonlinear acceleration and resonance scattering of ring current particles.
Organocatalytic Heterocyclization Driven by Dynamic Kinetic Resolution: Enantioselective Access to Multi‐heteroatomic Cyclic Structures Mediated by Cinchona Alkaloid‐based Catalysts
Authors: Capaccio V. , Capobianco A. , Stanzione A. , Pierri G. , Tedesco C. , Di Mola A. , Massa A. , Palombi L. 
Published: June 2017

AbstractA new class of multi‐heteroatomic cyclic compounds containing N, S and O has been achieved in an enantioselective fashion via desymmetrization of 2‐cyano‐N‐tosylbenzylidenimine with thiols and subsequent catalytic dynamic kinetic resolution (DKR). Both organo‐ and phase transfer catalysis based on cinchona alkaloids having two H‐bonding coordination sites proved to be effective to furnish very good level of enantioselectivity (up to 95:5 er) in the heterocyclization of racemic N‐Tosyl‐protected N,S‐acetals deriving from 2‐formyl benzonitriles.magnified image
Hexafluoroisopropanol‐Promoted Metal‐Free Allylation of Silyl Enol Ethers with Allylic Alcohols
Authors: Pérez Juana M. , Maquilón Cristina , Ramón Diego J. , Baeza Alejandro 
Published: June 2017

AbstractA metal‐free protocol for the reaction of silyl enol ethers with allylic alcohols based on the use of 1,1,1,3,3,3‐hexafluoroisopropanol as a promoter able to activate both reactants, is described. This simple and straightforward transformation proceeds smoothly under mild conditions, rendering the corresponding allylated products in generally good yields.
Better documentation in electronic medical records would lead to an increased use of lower extremity venous ultrasound in the inpatient setting: a retrospective study
Authors: Takechi Daisuke , Kuroda Naoto , Dote Hisashi , Kim Euido , Yonekawa Osamu , Watanabe Takuya , Urano Tetsumei , Homma Yoichiro 
Published: June 2017

AimWe hypothesized that the quality of the assessment of abnormal laboratory data in the emergency department (ED) could affect the hospital‐attending physicians’ decision‐making after a patient's hospitalization. To test this hypothesis, we investigated how patients with a positive D‐dimer result were reported by ED physicians in electronic medical records, and measured whether lower extremity venous ultrasonography examination was undertaken during hospitalization by the hospital‐attending physicians.MethodsIn an urban tertiary acute care general hospital in Japan, between January 2012 and December 2013, we included patients hospitalized after a positive D‐dimer measurement (≥1.0 μg/mL) that was taken in the emergency department. We retrospectively measured the quality of ED physician assessments. Then we examined whether that affected the decisions of attending physicians to order lower extremity venous ultrasonography examinations during hospitalization. The exposure variable was the quality of the ED physicians’ assessment of patients with positive D‐dimer results. The outcome was whether a lower extremity venous ultrasonography examination was ordered by the attending physician during hospitalization.ResultsWhen assessments were described by ED physicians for patients with positive D‐dimer results, the attending physicians frequently ordered lower extremity venous ultrasonography (odds ratio, 10.74; 95% confidence interval, 5.92–19.50), even if the assessments only contained “copied and pasted” laboratory data (odds ratio, 1.68; 95% confidence interval, 2.10–2.40).ConclusionsBetter documentation by ED physicians, regarding patients with positive D‐dimer results, strongly affected the decisions made by attending physicians to order lower extremity venous ultrasonography examination.
A Carbene Catalysis Strategy for the Synthesis of Protoilludane Natural Products
Authors: Hovey M. Todd , Cohen Daniel T. , Walden Daniel M. , Cheong Paul H.‐Y. , Scheidt Karl A. 
Published: June 2017

AbstractThe Armillaria and Lactarius genera of fungi produce the antimicrobial and cytotoxic mellolide, protoilludane, and marasmane sesquiterpenoids. We report a unified synthetic strategy to access the protoilludane, mellolide, and marasmane families of natural products. The key features of these syntheses are 1) the organocatalytic, enantioselective construction of key chiral intermediates from a simple achiral precursor, 2) the utility of a key 1,2‐cyclobutanediol intermediate to serve as a precursor to each natural product class, and 3) a direct chemical conversion of a protoilludane to a marasmane through serendipitous ring contraction, which provides experimental support for their proposed biosynthetic relationships.
Catalyst‐Controlled, Enantioselective, and Diastereodivergent Conjugate Addition of Aldehydes to Electron‐Deficient Olefins
Authors: Kan S. B. Jennifer , Maruyama Hiroki , Akakura Matsujiro , Kano Taichi , Maruoka Keiji 
Published: June 2017

AbstractA chiral‐amine‐catalyzed enantioselective and diastereodivergent method for aldehyde addition to electron‐deficient olefins is presented. Hydrogen bonding was used as a control element to achieve unusual anti selectivity, which was further elucidated through mechanistic and computational studies.