bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermal diffusivity measurement using thermographic method and performance evaluation by impedance spectroscopy for thermoelectric module
Authors: Otsuka Mioko , Terakado Hiroki , Homma Ryoei , Hasegawa Yasuhiro , Islam Md. Zahidul , Bastian Georg , Stuck Alexander 
Published: November 2016

Abstract
The thermal diffusivity of two bulk thermoelectric elements and a thermoelectric module was measured by an infrared camera using a thermographic method without any contact in air at room temperature. The estimated values for the elements (3.45 × 10−6 m2/s for a BiSb sample and 1.60 × 10−6 m2/s for a BiTe sample) were slightly larger than those measured in vacuum. The difference was explained as the effect of heat convection on the surface of the samples by solving the one-dimensional heat conduction equation numerically. The thermal diffusivity of thermoelectric elements in a thermoelectric module was also estimated using the thermographic method, and values of (1.1–1.7) × 10−6 m2/s in air were obtained, depending on the element. On the basis of the measurement results, the performance of the module was estimated using impedance spectroscopy, which can estimate not only the dimensionless figure of merit but also the thermal loss and response. The thermal response and thermal loss in air were similar to those in vacuum; however, the dimensionless figure of merit was 0.82 in vacuum and 0.70 in air.
Toward better assessment of tornado potential in typhoons: Significance of considering entrainment effects for CAPE
Authors: Sueki Kenta , Niino Hiroshi 
Published: November 2016

AbstractThe characteristics of typhoons that spawned tornadoes (tornadic typhoons: TTs) in Japan from 1991 to 2013 were investigated by composite analysis using the Japanese 55 year Reanalysis and compared with those of typhoons that did not spawn tornadoes (nontornadic typhoons: NTs). We found that convective available potential energy (CAPE), which considers the effects of entrainment (entraining CAPE: E‐CAPE), and storm‐relative environmental helicity (SREH) are significantly large in the northeast quadrant of TTs where tornadoes frequently occur and that E‐CAPE and SREH in that quadrant for TTs are larger than those for NTs. On the other hand, ordinary CAPE without entrainment does not account for the spatial distribution of tornado occurrences nor does it distinguish TTs from NTs. E‐CAPE is sensitive to humidity in the midtroposphere; thus, it is effective for detecting a conditionally unstable layer up to about 550 hPa, which is distinctive of TTs.
Rapid variations in deep ocean temperature detected in the Holocene
Authors: Bova Samantha C. , Herbert Timothy D. , Fox‐Kemper Baylor 
Published: November 2016

AbstractThe observational record of deep ocean variability is short, which makes it difficult to attribute the recent rise in deep ocean temperatures to anthropogenic forcing. Here we test a new proxy—the oxygen isotopic signature of individual benthic foraminifera—to detect rapid (i.e., monthly to decadal) variations in deep ocean temperature and salinity in the sedimentary record. We apply this technique at 1000 m water depth in the Eastern Equatorial Pacific during seven 200 year Holocene intervals. Variability in foraminifer δ18O over the past 200 years is below the detection limit, but δ18O signatures from two mid‐Holocene intervals indicate temperature swings >2°C within 200 years. More vigorous transport between the surface and deep ocean or stronger eddy variability than that observed in the historical record are potential explanations. Distinguishing externally forced climate trends in deep ocean properties from unforced variability should be possible with systematic analysis of suitable deep sea cores.
Force balance at the magnetopause determined with MMS: Application to flux transfer events
Authors: Zhao C. , Russell C. T. , Strangeway R. J. , Petrinec S. M. , Paterson W. R. , Zhou M. , Anderson B. J. , Baumjohann W. , Bromund K. R. , Chutter M. , Fischer D. , Le G. , Nakamura R. , Plaschke F. , Slavin J. A. , Torbert R. B. , Wei H. Y. 
Published: November 2016

AbstractThe Magnetospheric Multiscale mission (MMS) consists of four identical spacecraft forming a closely separated (≤10 km) and nearly regular tetrahedron. This configuration enables the decoupling of spatial and temporal variations and allows the calculation of the spatial gradients of plasma and electromagnetic field quantities. We make full use of the well cross‐calibrated MMS magnetometers and fast plasma instruments measurements to calculate both the magnetic and plasma forces in flux transfer events (FTEs) and evaluate the relative contributions of different forces to the magnetopause momentum variation. This analysis demonstrates that some but not all FTEs, consistent with previous studies, are indeed force‐free structures in which the magnetic pressure force balances the magnetic curvature force. Furthermore, we contrast these events with FTE events that have non‐force‐free signatures.
Optimizing estimates of annual variations and trends in geocenter motion and J2 from a combination of GRACE data and geophysical models
Authors: Sun Yu , Riva Riccardo , Ditmar Pavel 
Published: November 2016

AbstractThe focus of the study is optimizing the technique for estimating geocenter motion and variations in J2 by combining data from the Gravity Recovery and Climate Experiment (GRACE) satellite mission with output from an Ocean Bottom Pressure model and a Glacial Isostatic Adjustment (GIA) model. First, we conduct an end‐to‐end numerical simulation study. We generate input time‐variable gravity field observations by perturbing a synthetic Earth model with realistically simulated errors. We show that it is important to avoid large errors at short wavelengths and signal leakage from land to ocean, as well as to account for self‐attraction and loading effects. Second, the optimal implementation strategy is applied to real GRACE data. We show that the estimates of annual amplitude in geocenter motion are in line with estimates from other techniques, such as satellite laser ranging (SLR) and global GPS inversion. At the same time, annual amplitudes of C10 and C11 are increased by about 50% and 20%, respectively, compared to estimates based on Swenson et al. (2008). Estimates of J2 variations are by about 15% larger than SLR results in terms of annual amplitude. Linear trend estimates are dependent on the adopted GIA model but still comparable to some SLR results.
Widespread occurrence of silicate‐hosted magnetic mineral inclusions in marine sediments and their contribution to paleomagnetic recording
Authors: Chang Liao , Roberts Andrew P. , Heslop David , Hayashida Akira , Li Jinhua , Zhao Xiang , Tian Wei , Huang Qinghua 
Published: November 2016

AbstractMagnetic mineral inclusions occur commonly within other larger mineral phases in igneous rocks and have been demonstrated to preserve important paleomagnetic signals. While the usefulness of magnetic inclusions in igneous rocks has been explored extensively, their presence in sediments has only been speculated upon. The contribution of magnetic inclusions to the magnetization of sediments, therefore, has been elusive. In this study, we use transmission electron microscope (TEM) and magnetic methods to demonstrate the widespread preservation of silicate‐hosted magnetic inclusions in marine sedimentary settings. TEM analysis reveals detailed information about the microstructure, chemical composition, grain size, and spatial arrangement of nanoscale magnetic mineral inclusions within larger silicate particles. Our results confirm the expectation that silicate minerals can protect magnetic mineral inclusions from sulfate‐reducing diagenesis and increase significantly the preservation potential of iron oxides in inclusions. Magnetic inclusions should, therefore, be considered as a potentially important source of fine‐grained magnetic mineral assemblages and represent a missing link in a wide range of sedimentary paleomagnetic and environmental magnetic studies. In addition, we present depositional remanent magnetization (DRM) modeling results to assess the paleomagnetic recording capability of magnetic inclusions. Our simulation demonstrates that deposition of larger silicate particles with magnetic inclusions will be controlled by gravitational and hydrodynamic forces rather than by geomagnetic torques. Thus, even though these large silicates may contain ideal single‐domain particles, they cannot contribute meaningfully to paleomagnetic recording. However, smaller (e.g., silt‐ and clay‐sized) silicates with unidirectionally magnetized magnetic inclusions can potentially record a reliable DRM.
Distinct crustal structure of the North American Midcontinent Rift from P wave receiver functions
Authors: Zhang Hao , van der Lee Suzan , Wolin Emily , Bollmann Trevor A. , Revenaugh Justin , Wiens Douglas A. , Frederiksen Andrew W. , Darbyshire Fiona A. , Aleqabi Ghassan I. , Wysession Michael E. , Stein Seth , Jurdy Donna M. 
Published: November 2016

AbstractEighty‐two broadband seismic stations of the Superior Province Rifting Earthscope Experiment (SPREE) collected 2.5 years of continuous seismic data in the area of the high gravity anomaly associated with the Midcontinent Rift (MCR). Over 100 high‐quality teleseismic earthquakes were used for crustal P wave receiver function analysis. Our analysis reveals that the base of the sedimentary layer is shallow outside the MCR, thickens near the flanks where gravity anomalies are low, and shallows again in the MCR's center where the gravity anomalies peak. This pattern is similar to that found from local geophysical studies and is consistent with reverse faulting having accompanied the cessation of rifting at 1.1 Ga. Intermittent intracrustal boundaries imaged by our analysis might represent the bottom of the MCR's mostly buried dense volcanic layers. Outside the MCR, the Moho is strong, sharp, and relatively flat, both beneath the Archean Superior Province and the Proterozoic terranes to its south. Inside the MCR, two weaker candidate Mohos are found at depths up to 25 km apart in the rift's center. The intermediate layer between these discontinuities tapers toward the edges of the MCR. The presence of this transitional layer is remarkably consistent along the strike of the MCR, including beneath its jog in southern Minnesota, near the Belle Plaine Fault. We interpret these results as evidence for extensive underplating as a defining characteristic of the rift, which remains continuous along the Minnesota jog, where due to its orientation, it is minimally affected by the reverse faulting that characterizes the NNE striking parts of the rift.
Investigating seasonal methane emissions in Northern California using airborne measurements and inverse modeling
Authors: Johnson Matthew S. , Xi Xin , Jeong Seongeun , Yates Emma L. , Iraci Laura T. , Tanaka Tomoaki , Loewenstein Max , Tadić Jovan M. , Fischer Marc L. 
Published: November 2016

AbstractSeasonal methane (CH4) emissions in Northern California are evaluated during this study by using airborne measurement data and inverse model simulations. This research applies Alpha Jet Atmospheric eXperiment (AJAX) measurements obtained during January–February 2013, July 2014, and October–November 2014 over the San Francisco Bay Area (SFBA) and northern San Joaquin Valley (SJV) in order to constrain seasonal CH4 emissions in Northern California. The California Greenhouse Gas Emissions Measurement (CALGEM) a priori emission inventory was applied in conjunction with the Weather Research and Forecasting and Stochastic Time‐Inverted Lagrangian Transport model and inverse modeling techniques to optimize CH4 emissions. Comparing model‐predicted CH4 mixing ratios with airborne measurements, we find substantial underestimates suggesting that CH4 emissions were likely larger than the year 2008 a priori CALGEM emission inventory in Northern California. Using AJAX measurements to optimize a priori emissions resulted in CH4 flux estimates from the SFBA/SJV of 1.77 ± 0.41, 0.83 ± 0.31, and 1.06 ± 0.39 Tg yr−1 when using winter, summer, and fall flight data, respectively. Averaging seasonal a posteriori emission estimates (weighted by posterior uncertainties) results in SFBA/SJV annual CH4 emissions of 1.28 ± 0.38 Tg yr−1. A posteriori uncertainties are reduced more effectively in the SFBA/SJV region compared to state‐wide values indicating that the airborne measurements are most sensitive to emissions in this region. A posteriori estimates during this study suggest that dairy livestock was the source with the largest increase relative to the a priori CALGEM emission inventory during all seasons.
Cloud glaciation temperature estimation from passive remote sensing data with evolutionary computing
Authors: Carro‐Calvo L. , Hoose C. , Stengel M. , Salcedo‐Sanz S. 
Published: November 2016

AbstractThe phase partitioning between supercooled liquid water and ice in clouds in the temperature range between 0 and −37°C influences their optical properties and the efficiency of precipitation formation. Passive remote sensing observations provide long‐term records of the cloud top phase at a high spatial resolution. Based on the assumption of a cumulative Gaussian distribution of the ice cloud fraction as a function of temperature, we quantify the cloud glaciation temperature (CGT) as the 50th percentile of the fitted distribution function and its variance for different cloud top pressure intervals, obtained by applying an evolutionary algorithm (EA). EAs are metaheuristics approaches for optimization, used in difficult problems where standard approaches are either not applicable or show poor performance. In this case, the proposed EA is applied to 4 years of Pathfinder Atmospheres‐Extended (PATMOS‐x) data, aggregated into boxes of 1° × 1° and vertical layers of 5.5 hPa. The resulting vertical profile of CGT shows a characteristic sickle shape, indicating low CGTs close to homogeneous freezing in the upper troposphere and significantly higher values in the midtroposphere. In winter, a pronounced land‐sea contrast is found at midlatitudes, with lower CGTs over land. Among this and previous studies, there is disagreement on the sign of the land‐sea difference in CGT, suggesting that it is strongly sensitive to the detected and analyzed cloud types, the time of the day, and the phase retrieval method.
Tropical cyclone track direction climatology and its intraseasonal variability in the Australian region
Authors: Lavender Sally L. , Dowdy Andrew J. 
Published: November 2016

AbstractAspects of tropical cyclone (TC) activity, such as the influence of the El Niño‐Southern Oscillation and the variability of TC genesis location, have been examined in numerous previous studies. However, relatively few studies have examined aspects such as the influence of intraseasonal variability on TC track direction. Here we focus on a number of knowledge gaps relating to observed TC track directionality and intraseasonal variability in the Australian region. Climatological examinations are presented for TC track directional variability throughout the Australian region. In contrast to previous studies that have focused on the mean direction of TC movement in this region, TC tracks are examined here based on the full spectrum of track directions for a given location or region. Variability in initial TC track directions is investigated, including an examination of the influence of the Madden‐Julian oscillation (MJO). It is demonstrated that there is a considerable degree of seasonal and intraseasonal variation in TC motion in this region. These variations result from variations in genesis location throughout the TC season, as well as zonal wind anomalies associated with the influence of the MJO on the steering flow winds. Anomalous westerly steering flow occurs during MJO phase 4 − 5 and anomalous easterly flow during phase 8 − 1 in the western basin, with resulting changes in the proportion of TC tracks in each direction during these phases of the MJO. The results presented here are intended to provide improved seasonal TC activity guidance and enhanced resilience to TC impacts.
Impact of moisture source variation on decadal‐scale changes of precipitation in North China from 1951 to 2010
Authors: Jiang Zhihong , Jiang Shuai , Shi Yi , Liu Zhengyu , Li Wei , Li Laurent 
Published: November 2016

AbstractThe Hybrid Single‐Particle Lagrangian Integrated Trajectory platform is employed in this study to simulate trajectories of air parcels in the rainy season in North China during last six decades (1951–2010), with the purpose of investigating moisture sources, their variation, and the eventual relationship with precipitation in North China. Climatological trajectories indicate that moisture in North China originates, respectively, from Eurasia (14.4%), eastern China (10.2%), the Bay of Bengal‐South China Sea (33.8%), the Indian Ocean (10.7%), and the Pacific (30.9%). The spatiotemporal analysis of moisture trajectory based on extended empirical orthogonal function indicates that a decrease of precipitation in North China is caused mainly by a decrease of water vapor sources from the south, the Indian Ocean, the Bay of Bengal, and the South China Sea, which overwhelms an increase of water vapor sources from the North, mainly Eurasia, eastern China, and northern western North Pacific Ocean. In particular, the significant decrease of precipitation in the late 1970s (by 11.6%) is mainly caused by a 10.6% decrease of moisture from all sources. The Bay of Bengal, the South China Sea, and the Indian Ocean are dominant moisture source areas affecting the decadal‐scale variation of precipitation in North China.
Quantitative, nondestructive estimates of coarse root biomass in a temperate pine forest using 3‐D ground‐penetrating radar (GPR)
Authors: Molon Michelle , Boyce Joseph I. , Arain M. Altaf 
Published: November 2016

AbstractCoarse root biomass was estimated in a temperate pine forest using high‐resolution (1 GHz) 3‐D ground‐penetrating radar (GPR). GPR survey grids were acquired across a 400 m2 area with varying line spacing (12.5 and 25 cm). Root volume and biomass were estimated directly from the 3‐D radar volume by using isometric surfaces calculated with the marching cubes algorithm. Empirical relations between GPR reflection amplitude and root diameter were determined for 14 root segments (0.1–10 cm diameter) reburied in a 6 m2 experimental test plot and surveyed at 5–25 cm line spacing under dry and wet soil conditions. Reburied roots >1.4 cm diameter were detectable as continuous root structures with 5 cm line separation. Reflection amplitudes were strongly controlled by soil moisture and decreased by ~40% with a twofold increase in soil moisture. GPR line intervals of 12.5 and 25 cm produced discontinuous mapping of roots, and GPR coarse root biomass estimates (0.92 kgC m−2) were lower than those obtained previously with a site‐specific allometric equation due to nondetection of vertical roots and roots <1.5 cm diameter. The results show that coarse root volume and biomass can be estimated directly from interpolated 3‐D GPR volumes by using a marching cubes approach, but mapping of roots as continuous structures requires high inline sampling and line density (<5 cm). The results demonstrate that 3‐D GPR is viable approach for estimating belowground carbon and for mapping tree root architecture. This methodology can be applied more broadly in other disciplines (e.g., archaeology and civil engineering) for imaging buried structures.
Implementation and evaluation of a monthly water balance model over the US on an 800 m grid
Authors: Hostetler S. W. , Alder J. R. 
Published: November 2016

AbstractWe simulate the 1950–2010 water balance for the conterminous U.S. (CONUS) with a monthly water balance model (MWBM) using the 800 m Parameter‐elevation Regression on Independent Slopes Model (PRISM) data set as model input. We employed observed snow and streamflow data sets to guide modification of the snow and potential evapotranspiration components in the default model and to evaluate model performance. Based on various metrics and sensitivity tests, the modified model yields reasonably good simulations of seasonal snowpack in the West (range of bias of ±50 mm at 68% of 713 SNOTEL sites), the gradients and magnitudes of actual evapotranspiration, and runoff (median correlation of 0.83 and median Nash‐Sutcliff efficiency of 0.6 between simulated and observed annual time series at 1427 USGS gage sites). The model generally performs well along the Pacific Coast, the high elevations of the Basin and Range and over the Midwest and East, but not as well over the dry areas of the Southwest and upper Plains regions due, in part, to the apportioning of direct versus delayed runoff. Sensitivity testing and application of the MWBM to simulate the future water balance at four National Parks when driven by 30 climate models from the Climate Model Intercomparison Program Phase 5 (CMIP5) demonstrate that the model is useful for evaluating first‐order, climate driven hydrologic change on monthly and annual time scales.
Linking hydro‐morphology with invertebrate ecology in diverse morphological units of a large river‐floodplain system
Authors: Blettler Martín C. M. , Amsler Mario L. , Eberle Eliana G. , Szupiany Ricardo , Latosinski Francisco G. , Abrial Elie , Oberholster Paul J. , Espinola Luis A. , Paira Aldo , Poza Ailen , Rodrigues Capítulo Alberto 
Published: November 2016

AbstractInterdisciplinary research in the fields of ecohydrology and ecogeomorphology is becoming increasingly important as a way to understand how biological and physical processes interact with each other in river systems. The objectives of the current study were 1) to determine changes in invertebrate community due to hydrological stages, 2) to link local physical features [flow configuration, sediment composition and morphological feature) with the ecological structure between and within dissimilar morphological units (meander and confluence), and 3) to determine the existence and the origin of bed hydro‐geomorphic patches, determining their ecological structure. Results were discussed in the frame of prevailing ecological models and concepts. The study site extends over a floodplain area of the large Paraná River (Argentina), including minor and major secondary channels as well as the main channel. Overall results suggested that hydrodynamics was the driving force determining distribution patterns of benthic assemblages in the floodplain. However, while the invertebrates living in minor secondary channels seem to benefit from flooding, this hydrological phase had the opposite effect on organisms from the main and major secondary channels. We also found a clear linkage between physical features and invertebrate ecology, which caused a dissimilar fauna structure between and within the meander and the confluence. Furthermore, several sandy‐patches were recorded in the confluence. These patches were colonized by the particular benthic assemblage recorded in the main channel, supported the view of rivers as patchy discontinua, under uncertain ecological equilibrium.