bluuebunny/crossref_metadata_2025 huggingface dataset:
The assassin bug subfamily Harpactorinae (Hemiptera: Reduviidae) from Vietnam: an annotated checklist of species
Authors: LAM TRUONG XUAN , CAI WANZHI , TOMOKUNI MASAAKI , ISHIKAWA TADASHI
Published: March 2015

A checklist of all known Vietnamese species of the assassin bug subfamily Harpactorinae (Hemiptera: Heteroptera: Reduviidae) is presented with distributional and taxonomic notes. Sixty-five species in 35 genera of the subfamily are recognized in Vietnam. Eleven genera and 32 species are reported herein for the first time from this country. Newly recorded genera are Henricohahnia Breddin, 1900, Kalonotocoris Miller, 1941, Lingnania China, 1940, Lopodytes Stål, 1853, Macracanthopsis Reuter, 1881, Sclomina Stål, 1861, Serendiba Distant, 1906, Serendus Hsiao, 1979, Vesbius Stål, 1866, Villanovanus Distant, 1904, and Yolinus Amyot & Serville, 1843. New record species are Biasticus confusus Hsiao, 1979, B. flavinotus (Matsumura, 1913), Cosmolestes annulipes Distant, 1879, C. pulcher Hsiao, 1979, Cydnocoris fasciatus Reuter, 1881, C. gilvus (Burmeister, 1838), Endochus nigricornis Stål, 1859, Henricohahnia vittata Miller, 1954, Isyndus heros (Fabricius, 1803), I. pilosipes Reuter, 1881, Kalonotocoris curvipes Miller, 1941, Lingnania braconiformis China, 1940, Lopodytes spectabilis Miller, 1941, Macracanthopsis nodipes Reuter, 1881, Sclomina erinacea Stål, 1861, Serendiba nigrospina Hsiao, 1979, S. staliana (Horváth, 1879), Serendus geniculatus Hsiao, 1979, Sphedanolestes annulipes Distant, 1903, S. gularis Hsiao, 1979, S. impressicollis (Stål, 1861), S. pubinotus Reuter, 1881, S. trichrous Stål, 1874, S. xiongi Cai & Cai, 2004, Sycanus croceus Hsiao, 1979, Velinus annulatus Distant, 1879, V. malayus (Stål, 1863), V. rufiventris Hsiao, 1979, Vesbius purpureus (Thunberg, 1784), V. sanguinosus Stål, 1874, Villanovanus nigrorufus Hsiao, 1979, and Yolinus albopustulatus China, 1940. All the species are examined with Vietnamese materials except for Agriosphodrus dohrni (Signoret, 1862), Cydnocoris russatus Stål, 1867, and Sycanus atrocoeruleus Signoret, 1862.
The Microphysics of Ice and Precipitation Development in Tropical Cumulus Clouds
Authors: Lawson R. Paul , Woods Sarah , Morrison Hugh
Published: March 2015

The rapid glaciation of tropical cumulus clouds has been an enigma and has been debated in the literature for over 60 years. Possible mechanisms responsible for the rapid freezing have been postulated, but until now direct evidence has been lacking. Recent high-speed photography of electrostatically suspended supercooled drops in the laboratory has shown that freezing events produce small secondary ice particles. Aircraft observations from the Ice in Clouds Experiment–Tropical (ICE-T), strongly suggest that the drop-freezing secondary ice production mechanism is operating in strong, tropical cumulus updraft cores. The result is the production of small ice particles colliding with large supercooled drops (hundreds of microns up to millimeters in diameter), producing a cascading process that results in rapid glaciation of water drops in the updraft. The process was analyzed from data collected using state-of-the-art cloud particle probes during 54 Learjet penetrations of strong cumulus updraft cores over open ocean in a temperature range from 5° to −20°C. Repeated Learjet penetrations of an updraft core containing 3–5 g m−3 supercooled liquid showed an order-of-magnitude decrease in liquid mass concentration 3 min later at an elevation 1–1.5 km higher in the cloud. The aircraft observations were simulated using a one-dimensional cloud model with explicit bin microphysics. The model was initialized with drop and ice particle size distributions observed prior to rapid glaciation. Simulations show that the model can explain the observed rapid glaciation by the drop-freezing secondary ice production process and subsequent riming, which results when large supercooled drops collide with ice particles.
Satellite Inference of Thermals and Cloud-Base Updraft Speeds Based on Retrieved Surface and Cloud-Base Temperatures
Authors: Zheng Youtong , Rosenfeld Daniel , Li Zhanqing
Published: March 2015

Updraft speeds of thermals have always been difficult to measure, despite the significant role they play in transporting pollutants and in cloud formation and precipitation. In this study, updraft speeds in buoyancy-driven planetary boundary layers (PBLs) measured by Doppler lidar are found to be correlated with properties of the PBL and surface over the Southern Great Plains (SGP) site operated by the U.S. Department of Energy’s Atmospheric Radiation Measurement Program (ARM). Based on the relationships found here, two approaches are proposed to estimate both maximum (Wmax) and cloud-base (Wcb) updraft speeds using satellite data together with some ancillary meteorological data of PBL depth, wind speed at 10-m height, and air temperature at 2-m height. The required satellite input data are cloud-base and surface skin temperatures. PBL depth can be determined by using cloud-base temperature in combination with European Centre for Medium-Range Weather Forecasts (ECMWF) interim reanalysis data. Validation against lidar-measured updraft speeds demonstrated the feasibility of retrieving Wmax and Wcb using high-resolution Suomi–National Polar-Orbiting Partnership Visible Infrared Imaging Radiometer Suite (Suomi-NPP VIIRS) measurements over land for PBLs with thermally driven convective clouds during the satellite overpass time. The root-mean-square errors (RMSE) of Wmax and Wcb are 0.32 and 0.42 m s−1, respectively. This method does not work for a stable or a mechanically driven PBL.
Stability and Instability Criteria for Idealized Precipitating Hydrodynamics
Authors: Hernandez-Duenas Gerardo , Smith Leslie M. , Stechmann Samuel N.
Published: March 2015

A linear stability analysis is presented for fluid dynamics with water vapor and precipitation, where the precipitation falls relative to the fluid at speed VT. The aim is to bridge two extreme cases by considering the full range of VT values: (i) VT = 0, (ii) finite VT, and (iii) infinitely fast VT. In each case, a saturated precipitating atmosphere is considered, and the sufficient conditions for stability and instability are identified. Furthermore, each condition is linked to a thermodynamic variable: either a variable θs, which denotes the saturated potential temperature, or the equivalent potential temperature θe. When VT is finite, separate sufficient conditions are identified for stability versus instability: dθe/dz > 0 versus dθs/dz < 0, respectively. When VT = 0, the criterion dθs/dz = 0 is the single boundary that separates the stable and unstable conditions; and when VT is infinitely fast, the criterion dθe/dz = 0 is the single boundary. Asymptotics are used to analytically characterize the infinitely fast VT case, in addition to numerical results. Also, the small-VT limit is identified as a singular limit; that is, the cases of VT = 0 and small VT are fundamentally different. An energy principle is also presented for each case of VT, and the form of the energy identifies the stability parameter: either dθs/dz or dθe/dz. Results for finite VT have some resemblance to the notion of conditional instability: separate sufficient conditions exist for stability versus instability, with an intermediate range of environmental states where stability or instability is not definitive.
Characterizing ENSO Coupled Variability and Its Impact on North American Seasonal Precipitation and Temperature
Authors: L’Heureux Michelle L. , Tippett Michael K. , Barnston Anthony G.
Published: March 2015

Two questions are addressed in this paper: whether ENSO can be adequately characterized by simple, seasonally invariant indices and whether the time series of a single component—SST or OLR—provides a sufficiently complete representation of ENSO for the purpose of quantifying U.S. climate impacts. Here, ENSO is defined as the leading mode of seasonally varying canonical correlation analysis (CCA) between anomalies of tropical Pacific SST and outgoing longwave radiation (OLR). The CCA reveals that the strongest regions of coupling are mostly invariant as a function of season and correspond to an OLR region located in the central Pacific Ocean (CP-OLR) and an SST region in the eastern Pacific that coincides with the Niño-3 region. In a linear context, the authors explore whether the use of a combined index of these SST and OLR regions explains additional variance of North American temperature and precipitation anomalies beyond that described by using a single index alone. Certain seasons and regions benefit from the use of a combined index. In particular, a combined index describes more variability in winter/spring precipitation and summer temperature.
The Link between the North Pacific Climate Variability and the North Atlantic Oscillation via Downstream Propagation of Synoptic Waves
Authors: Drouard Marie , Rivière Gwendal , Arbogast Philippe
Published: March 2015

The North Atlantic Oscillation (NAO) response to the northeast Pacific climate variability is examined using the ERA-40 dataset. The main objective is to validate a mechanism involving downstream wave propagation processes proposed in a recent idealized companion study: a low-frequency planetary-scale ridge (trough) anomaly located in the eastern Pacific–North American sector induces more equatorward (poleward) propagation of synoptic-scale wave packets on its downstream side, which favors the occurrence of anticyclonic (cyclonic) wave breakings in the Atlantic sector and the positive (negative) NAO phase.

The mechanism first provides an interpretation of the canonical impact of the El Niño–Southern Oscillation on the NAO in late winter. The wintertime relationship between the Pacific–North American oscillation (PNA) and the NAO is also investigated. For out-of-phase fluctuations between the PNA and NAO indices (i.e., the most recurrent situation in late winter), the eastern Pacific PNA ridge (trough) anomaly modifies the direction of downstream wave propagation, triggering more anticyclonic (cyclonic) wave breakings over the North Atlantic. For in-phase fluctuations, the effect of the eastern Pacific PNA anomalies is cancelled out by the North American PNA anomalies. The latter anomalies being deeper and more centered in the latitudinal band of downstream wave propagation, they are able to reverse the direction of wave propagation just before waves enter the Atlantic domain. The contrasting relationship between the PNA and NAO is similar to what occurs for the two leading hemispheric EOFs of geopotential height: the northern annular mode (NAM) and the cold ocean–warm land (COWL) pattern. The proposed mechanism provides a physical meaning for the NAM and COWL patterns.
Rainfall in the Andean Páramo: New Insights from High-Resolution Monitoring in Southern Ecuador
Authors: Padrón Ryan S. , Wilcox Bradford P. , Crespo Patricio , Célleri Rolando
Published: March 2015

In mountainous regions, rainfall plays a key role in water supply for millions of people. However, rainfall data for these sites are limited and generally of low quality, making it difficult to evaluate the nature, amount, and timing of rainfall. This is particularly true for the páramo, a high-elevation grassland in the northern Andes that is a primary source of water for large populations in Ecuador, Colombia, and Venezuela. In this study, high-resolution laser disdrometer data and standard tipping-bucket rain gauge data were used to improve knowledge of rainfall in the páramo. For 36 months, rainfall was monitored in a high-elevation (3780 m MSL) headwater catchment in southern Ecuador. Average annual rainfall during this period was 1345 mm. Results indicate that (i) when input from very low–intensity events (drizzle) is taken into account, rainfall is 15% higher than previously thought; (ii) rainfall occurs throughout the year (only approximately 12% of the days are dry); (iii) rainfall occurs primarily as drizzle (80% of rainfall duration), which accounts for 29% of total rainfall amount; and (iv) the timing and average intensity of rainfall varies throughout the year (shorter afternoon events are common from October to May, whereas longer night events—with lower intensities—are more frequent from June to September). Although some of these numbers may vary regionally, the results contribute to a better understanding of rainfall in the wet Andean páramo.
On the Use of a Water Balance to Evaluate Interannual Terrestrial ET Variability
Authors: Han Eunjin , Crow Wade T. , Hain Christopher R. , Anderson Martha C.
Published: March 2015

Accurately measuring interannual variability in terrestrial evapotranspiration ET is a major challenge for efforts to detect trends in the terrestrial hydrologic cycle. Based on comparisons with annual values of terrestrial evapotranspiration derived from a terrestrial water balance analysis, past research has cast doubt on the ability of existing products to accurately capture variability. Using a variety of estimates, this analysis reexamines this conclusion and finds that estimates of variations obtained from a land surface model are more strongly correlated with independently acquired from thermal infrared remote sensing than derived from water balance considerations. This tendency is attributed to significant interannual variations in terrestrial water storage neglected by the water balance approach. Overall, results demonstrate the need to reassess perceptions concerning the skill of estimates derived from land surface models and show the value of accurate remotely sensed ET products for the validation of interannual ET.
Estimation of Spatial Correlation of Drop Size Distribution Parameters and Rain Rate Using NASA’s S-Band Polarimetric Radar and 2D Video Disdrometer Network: Two Case Studies from MC3E
Authors: Bringi V. N. , Tolstoy L. , Thurai M. , Petersen W. A.
Published: March 2015

Polarimetric radar data obtained at high spatial and temporal resolutions offer a distinct advantage in estimating the spatial correlation function of drop size distribution (DSD) parameters and rain rate compared with a fixed gauge–disdrometer network. On two days during the 2011 Midlatitude Continental Convective Clouds Experiment (MC3E) campaign in Oklahoma, NASA’s S-band polarimetric radar (NPOL) performed repeated PPI scans every 40 s over six 2D video disdrometer (2DVD) sites, located 20–30 km from the radar. The two cases were 1) a rapidly evolving multicell rain event (with large drops) and 2) a long-duration stratiform rain event. From the time series at each polar pixel, the Pearson correlation coefficient is computed as a function of distance along each radial in the PPI scan. Azimuthal dependence is found, especially for the highly convective event. A pseudo-1D spatial correlation is computed that is fitted to a modified-exponential function with two parameters (decorrelation distance R0 and shape F). The first event showed significantly higher spatial variability in rain rate (shorter decorrelation distance R0 = 3.4 km) compared with the second event with R0 = 10.2 km. Further, for the second event, the spatial correlation of the DSD parameters and rain rate from radar showed good agreement with 2DVD-based spatial correlations over distances ranging from 1.5 to 7 km. The NPOL also performed repeated RHI scans every 40 s along one azimuth centered over the 2DVD network. Vertical correlations of the DSD parameters as well as the rainwater content were determined below the melting level, with the first event showing more variability compared with the second event.
An Immersed Boundary Geometric Preprocessor for Arbitrarily Complex Terrain and Geometry
Authors: Senocak Inanc , Sandusky Micah , DeLeon Rey , Wade Derek , Felzien Kyle , Budnikova Marianna
Published: March 2015

There is a growing interest to apply the immersed boundary method to compute wind fields over arbitrarily complex terrain. The computer implementation of an immersed boundary module into an existing flow solver can be accomplished with minor modifications to the rest of the computer program. However, a versatile preprocessor is needed at the first place to extract the essential geometric information pertinent to the immersion of an arbitrarily complex terrain inside a 3D Cartesian mesh. Errors in the geometric information can negatively impact the correct implementation of the immersed boundary method as part of the solution algorithm. Additionally, the distance field from the terrain is needed to implement various subgrid-scale turbulence models and to initialize wind fields over complex terrain. Despite the popularity of the immersed boundary method, procedures used in the geometric preprocessing stage have received less attention. The present study found that concave and convex regions of complex terrain are particularly challenging to process with existing procedures discussed in the literature. To address this issue, a geometric preprocessor with a distance field solver was presented, and the solver demonstrated its versatility for arbitrarily complex geometry, terrain, and urban environments. The distance field solver uses the initial distance field at the immersed boundaries and propagates it to the rest of the domain by solving the Eikonal equation with the fast sweeping method.
Improved Moments Estimation for VHF Active Phased Array Radar Using Fuzzy Logic Method
Authors: Allabakash S. , Yasodha P. , Bianco L. , Reddy S. Venkatramana , Srinivasulu P.
Published: March 2015

Various nonatmospheric signals contaminate radar wind profiler data, introducing bias into the moments and wind velocity estimation. This study applies a fuzzy logic–based method to Doppler velocity spectra to identify and eliminate the clutter echoes. This method uses mathematical analyses and a fuzzy inference system applied to each Doppler velocity spectrum to separate the atmospheric signals from the clutter. After eliminating the clutter, an adaptive algorithm is used to estimate mean Doppler velocities accurately. This combination of techniques is applied to the spectral data obtained by the newly developed 53-MHz active phased array radar located at the National Atmospheric Research Laboratory (NARL), Gadanki, India (13.5°N, 79°E). Winds derived using the conventional method and the method developed for this study are compared with those obtained by collocated GPS radiosonde. The comparison shows that the present method derives the winds more accurately compared to the conventional method.
Optimal Spectral Decomposition (OSD) for Ocean Data Assimilation
Authors: Chu Peter C. , Tokmakian Robin T. , Fan Chenwu , Sun L. Charles
Published: March 2015

Optimal spectral decomposition (OSD) is applied to ocean data assimilation with variable (temperature, salinity, or velocity) anomalies (relative to background or modeled values) decomposed into generalized Fourier series, such that any anomaly is represented by a linear combination of products of basis functions and corresponding spectral coefficients. It has three steps: 1) determination of the basis functions, 2) optimal mode truncation, and 3) update of the spectral coefficients from innovation (observational increment). The basis functions, depending only on the topography of the ocean basin, are the eigenvectors of the Laplacian operator with the same lateral boundary conditions as the assimilated variable anomalies. The Vapnik–Chervonkis dimension is used to determine the optimal mode truncation. After that, the model field updates due to innovation through solving a set of a linear algebraic equations of the spectral coefficients. The strength and weakness of the OSD method are demonstrated through a twin experiment using the Parallel Ocean Program (POP) model.
Polarimetric Variables Retrieval with Clutter Suppression for Staggered PRT Sequences
Authors: Nguyen Cuong M. , Chandrasekar V.
Published: March 2015

This paper presents a procedure to filter ground clutter from dual-polarized staggered pulse repetition time (PRT) radar data in simultaneous and alternating transmission modes for polarimetric variables retrieval. The filter is designed in the time domain so that polarimetric variables such as the differential phase () and the copolar correlation coefficient () can be estimated directly from clutter-filtered time series data using a conventional method. In the case of the simultaneous mode, a single filter is used for both channels to maintain the signal correlation after filtering. For the alternating mode, because the polarizations are transmitted in different waveforms, two separate filters are required. However, the filters are designed so that the responses of the filters to the signals are identical within the extended Doppler range. Based on radar simulation, it is shown that the method can provide accurate retrieval of polarimetric variables even in the case of strong clutter contamination. Also, the performance of the method is illustrated on dual-polarized staggered PRT ⅔ data from the NASA dual-frequency dual-polarized Doppler radar (D3R).
Developing and Evaluating Ice Cloud Parameterizations for Forward Modeling of Radar Moments Using in situ Aircraft Observations
Authors: Maahn Maximilian , Löhnert Ulrich , Kollias Pavlos , Jackson Robert C. , McFarquhar Greg M.
Published: March 2015

Observing ice clouds using zenith pointing millimeter cloud radars is challenging because the transfer functions relating the observables to meteorological quantities are not uniquely defined. Here, the authors use a spectral radar simulator to develop a consistent dataset containing particle mass, area, and size distribution as functions of size. This is an essential prerequisite for radar sensitivity studies and retrieval development. The data are obtained from aircraft in situ and ground-based radar observations during the Indirect and Semi-Direct Aerosol Campaign (ISDAC) campaign in Alaska. The two main results of this study are as follows: 1) An improved method to estimate the particle mass–size relation as a function of temperature is developed and successfully evaluated by combining aircraft in situ and radar observations. The method relies on a functional relation between reflectivity and Doppler velocity. 2) The impact on the Doppler spectrum by replacing measurements of particle area and size distribution by recent analytical expressions is investigated. For this, higher-order moments such as skewness and kurtosis as well as the slopes of the Doppler spectrum are also used as a proxy for the Doppler spectrum. For the area–size relation, it is found that a power law is not sufficient to describe particle area and small deviations from a power law are essential for obtaining consistent higher moments. For particle size distributions, the normalization approach for the gamma distribution of Testud et al., adapted to maximum diameter as size descriptor, is preferred.
Using Evolutionary Programs to Maximize Minimum Temperature Forecast Skill
Authors: Roebber Paul J.
Published: March 2015

Evolutionary program ensembles are developed and tested for minimum temperature forecasts at Chicago, Illinois, at forecast ranges of 36, 60, 84, 108, 132, and 156 h. For all forecast ranges examined, the evolutionary program ensemble outperforms the 21-member GFS model output statistics (MOS) ensemble when considering root-mean-square error and Brier skill score. The relative advantage in root-mean-square error widens with forecast range, from 0.18°F at 36 h to 1.53°F at 156 h while the probabilistic skill remains positive throughout. At all forecast ranges, probabilistic forecasts of abnormal conditions are particularly skillful compared to the raw GFS guidance.

The evolutionary program reliance on particular forecast inputs is distinct from that obtained from considering multiple linear regression models, with less reliance on the GFS MOS temperature and more on alternative data such as upstream temperatures at the time of forecast issuance, time of year, and forecasts of wind speed, precipitation, and cloud cover. This weighting trends away from current observations and toward seasonal (climatological) measures as forecast range increases.

Using two different forms of ensemble member subselection, a Bayesian model combination calibration is tested on both ensembles. This calibration had limited effect on evolutionary program ensemble skill but was able to improve MOS ensemble performance, reducing but not eliminating the skill gap between them. The largest skill differentials occurred at the longest forecast ranges, beginning at 132 h. A hybrid, calibrated ensemble was able to provide some further increase in skill.
A Framework for Diagnosing Seasonal Prediction through Canonical Event Analysis
Authors: Roundy Joshua K. , Yuan Xing , Schaake John , Wood Eric F.
Published: March 2015

Hydrologic extremes in the form of flood and drought have large impacts on society that can be reduced through preparations made possible by seasonal prediction. However, the skill of seasonal predictions from global climate models is uncertain, which severely limits their practical use. In the past, the skill assessment has been limited to a single temporal or spatial resolution for a short hindcast period, which is prone to sampling errors, and noise that leads to uncertainty. In this work a framework that uses “canonical” forecast events, or averages in space–time, to provide a more certain assessment of when and where models are skillful is developed. This framework is demonstrated by using NCEP’s Climate Forecast System, version 2, hindcast dataset for precipitation and temperature over the contiguous United States (CONUS). As part of the canonical event analyses, the probabilistic predictability metric (PPM) is used to define spatial and seasonal variability of forecast skill and its attribution to El Niño–Southern Oscillation (ENSO) over the CONUS. The PPM indicates that there are clear seasonal and spatial patterns of model skill that provide a better understanding of when and where to have confidence in model predictions as compared to a skill metric based on a single temporal and spatial scale. Furthermore, the canonical event analysis also facilitates the attribution of spatiotemporal variations of precipitation predictive skill to the antecedent ENSO conditions. This work illustrates the importance of using canonical event analysis to diagnose seasonal predictions and discusses its extensions for model development.
Rapid-Scan, Polarimetric, Doppler Radar Observations of Tornadogenesis and Tornado Dissipation in a Tornadic Supercell: The “El Reno, Oklahoma” Storm of 24 May 2011*
Authors: Houser Jana Lesak , Bluestein Howard B. , Snyder Jeffrey C.
Published: March 2015

On 24 May 2011, a mobile, rapid-scan, X-band, polarimetric, Doppler radar (RaXPol) collected data on a supercell as it produced two tornadoes near El Reno, Oklahoma. The first tornado, rated an EF-3, was documented from intensification to decay, and the genesis and intensification of a second tornado that was rated an EF-5 was subsequently also documented.

The objective of this study is to examine the spatiotemporal evolution of the rotation associated with the tornadoes (i) as the first tornado weakened to subtornadic intensity and (ii) as the second tornado formed and intensified. It is found that weakening did not occur monotonically. The transition from tornadic to subtornadic intensity over the depth of the radar volume (~4 km) occurred in less than 30 s, but this behavior is contingent upon the threshold for Doppler shear used to define the tornado. Similarly, the onset of a tornadic-strength Doppler velocity couplet occurred within a 30-s period over all elevations.

Additionally, the evolution of storm-scale features associated with tornado dissipation and tornadogenesis is detailed. These features evolved considerably over relatively short time intervals (1–4 min). It is shown that during the transition period between the two tornadoes, two mesocyclones were present, but neither the tornadoes nor the mesocyclones evolved in a manner entirely consistent with any published conceptual model of supercell cycling, although certain aspects were similar to classic conceptual models. The mesocyclone and the tornado evolved differently from each other, in a manner that resembles a hybrid between the occluding and nonoccluding cyclic mesocyclogenesis models presented by Adlerman and Droegemeier.
A Vertically Flow-Following Icosahedral Grid Model for Medium-Range and Seasonal Prediction. Part I: Model Description
Authors: Bleck Rainer , Bao Jian-Wen , Benjamin Stanley G. , Brown John M. , Fiorino Michael , Henderson Thomas B. , Lee Jin-Luen , MacDonald Alexander E. , Madden Paul , Middlecoff Jacques , Rosinski James , Smirnova Tanya G. , Sun Shan , Wang Ning
Published: March 2015

A hydrostatic global weather prediction model based on an icosahedral horizontal grid and a hybrid terrain-following/isentropic vertical coordinate is described. The model is an extension to three spatial dimensions of a previously developed, icosahedral, shallow-water model featuring user-selectable horizontal resolution and employing indirect addressing techniques. The vertical grid is adaptive to maximize the portion of the atmosphere mapped into the isentropic coordinate subdomain. The model, best described as a stacked shallow-water model, is being tested extensively on real-time medium-range forecasts to ready it for possible inclusion in operational multimodel ensembles for medium-range to seasonal prediction.
Predicting the Real-Time Multivariate Madden–Julian Oscillation Index through a Low-Order Nonlinear Stochastic Model
Authors: Chen Nan , Majda Andrew J.
Published: March 2015

A new low-order nonlinear stochastic model is developed to improve the predictability of the Real-time Multivariate Madden–Julian oscillation (MJO) index (RMM index), which is a combined measure of convection and circulation. A recent data-driven, physics-constrained, low-order stochastic modeling procedure is applied to the RMM index. The result is a four-dimensional nonlinear stochastic model for the two observed RMM variables and two hidden variables involving correlated multiplicative noise defined through energy-conserving nonlinear interaction. The special structure of the low-order model allows efficient data assimilation for the initialization of the hidden variables that facilitates the ensemble prediction algorithm. An information-theoretic framework is applied to the calibration of model parameters over a short training phase of 3 yr. This framework involves generalizations of the anomaly pattern correlation, the RMS error, and the information deficiency in the model forecast. The nonlinear stochastic models show skillful prediction for 30 days on average in these metrics. More importantly, the predictions succeed in capturing the amplitudes of the RMM index and the useful skill of forecasting strong MJO events is around 40 days. Furthermore, information barriers to prediction for linear models imply the necessity of the nonlinear interactions between the observed and hidden variables as well as the multiplicative noise in these low-order stochastic models.
Development of Anomalous Temperature Regimes over the Southeastern United States: Synoptic Behavior and Role of Low-Frequency Modes
Authors: Westby Rebecca M. , Black Robert X.
Published: March 2015

During winter, anomalous temperature regimes (ATRs), which include cold-air outbreaks (CAOs) and warm waves (WWs), have important impacts in the southeastern United States. This study provides a synoptic–dynamic characterization of ATRs in the southeastern United States from 1949 to 2011 through composite time-evolution analyses. Events are categorized by the sign and amplitude of relevant low-frequency modes. During CAO (WW) onset, negative (positive) geopotential height anomalies are observed in the upper troposphere over the Southeast with oppositely signed anomalies in the lower troposphere over the central United States. In most cases, there is a surface east–west geopotential height anomaly dipole, with anomalous northerly (CAO) or southerly (WW) flow into the Southeast leading to cold or warm surface air temperature anomalies, respectively. Companion potential vorticity anomaly analyses reveal prominent features in the mid- to upper troposphere consistent with the coincident geopotential height anomaly patterns. Ultimately, synoptic-scale disturbances are found to serve as dynamic triggers for ATR events, while low-frequency modes provide a favorable environment for ATR onset. The results provide a qualitative indication of the role of low-frequency modes in ATR onset. In WW (CAO) events influenced by low-frequency modes, the North American geopotential height anomaly pattern arises in part as a downstream (regional) manifestation of the negative Pacific–North American pattern (North Atlantic Oscillation). Interestingly, the North Atlantic Oscillation contributes to both CAO onset and demise. Thus, these results indicate that low-frequency modes also affect event duration (CAOs). One general distinction found for ATRs is that CAOs involve substantial airmass transport while WW formation is more regional in nature.
The 2012 Triply Nested, High-Resolution Operational Version of the Hurricane Weather Research and Forecasting Model (HWRF): Track and Intensity Forecast Verifications
Authors: Goldenberg Stanley B. , Gopalakrishnan Sundararaman G. , Tallapragada Vijay , Quirino Thiago , Marks Frank , Trahan Samuel , Zhang Xuejin , Atlas Robert
Published: March 2015

The Hurricane Weather Research and Forecasting Model (HWRF) was operationally implemented with a 27-km outer domain and a 9-km moving nest in 2007 (H007) as a tropical cyclone forecast model for the North Atlantic and eastern Pacific hurricane basins. During the 2012 hurricane season, a modified version of HWRF (H212), which increased horizontal resolution by adding a third (3 km) nest within the 9-km nest, replaced H007. H212 thus became the first operational model running at convection-permitting resolution. In addition, there were modifications to the initialization, model physics, tracking algorithm, etc. This paper compares H212 hindcast forecasts for the 2010–11 Atlantic hurricane seasons with forecasts from H007 and H3GP, a triply nested research version of HWRF. H212 reduced track forecast errors for almost all forecast times versus H007 and H3GP. H3GP was superior for intensity forecasts, although H212 showed some improvement over H007. Stratifying the cases by initial vertical wind shear revealed that the main weakness for H212 intensity forecasts was for cases with initially high shear. In these cases, H212 over- and under-intensified storms that were initially stronger and weaker, respectively. These results suggest the primary deficiency negatively impacting H212 intensity forecasts, especially in cases of rapid intensification, was that physics calls were too infrequent for the 3-km inner mesh. Correcting this deficiency along with additional modifications in the 2013 operational version yielded improved track and intensity forecasts. These intensity forecasts were comparable to statistical–dynamical models, showing that dynamical models can contribute to a decrease in operational forecast errors.
Impacts of a Storm Merger on the 24 May 2011 El Reno, Oklahoma, Tornadic Supercell
Authors: Tanamachi Robin L. , Heinselman Pamela L. , Wicker Louis J.
Published: March 2015

On 24 May 2011, a tornadic supercell (the El Reno, Oklahoma, storm) produced tornadoes rated as category 3 and 5 events on the enhanced Fujita scale (EF3 and EF5, respectively) during a severe weather outbreak. The transition (“handoff”) between the two tornadoes occurred as the El Reno storm merged with a weaker, ancillary storm. To examine the impacts of the merger on the dynamics of these storms, a series of three-dimensional cloud-scale analyses are created by assimilating 1-min volumetric observations from the National Weather Radar Testbed’s phased array radar into a numerical cloud model using the local ensemble transform Kalman filter technique. The El Reno storm, its updrafts, and vortices in the analyzed fields are objectively identified, and the changes in these objects before, during, and after the merger are examined. It is found that the merger did not cause the tornado handoff, which preceded the updraft merger by about 5 min. Instead, the handoff likely resulted from midlevel mesocyclone occlusion, in which the midlevel mesocyclone split and a portion is shed rearward with respect to storm motion. During the merger process, the midlevel mesocyclone and updraft structure in the El Reno storm became relatively disorganized. New updraft pulses that formed above colliding outflow boundaries between the two storms tilted environmental vorticity from low levels to generate an additional midlevel vortex that later merged with the El Reno storm’s midlevel mesocyclone. Once the ~10-min merger process was complete, the El Reno storm and its mesocyclone rapidly reintensified, as access to buoyant inflow sector air was restored.
Resistance Furnace Temperature Control System Based on OPC and MATLAB
Authors: Cao Jiangtao , Ye Qiang , Li Ping
Published: March 2015

This paper presents the application results of a fuzzy proportional–integral–derivative controller of temperature in an industrial resistance furnace. The challenges arise from the features of resistance furnaces such as non-linearity, strong inertia, large lag, and time-varying parameters. A fuzzy proportional–integral–derivative controller is adopted here to overcome these challenges. The hardware part of the control system is an ECS-700 distributed control system and an industrial PC, and the software part is built on Object Linking and Embedding for process control technology and MATLAB. The experimental results on an industrial furnace system show that the proposed fuzzy proportional–integral–derivative controller achieves better control performance with shorter setting time and smaller overshoot.
Advanced Control in a Delayed Coking Furnace
Authors: Su Chengli , Shi Huiyuan , Li Ping , Cao Jiangtao
Published: March 2015

This article reports an industrial application of advanced control in a delayed coking furnace unit. The advanced control is required because of the semi-batch and semi-continuous nature of the unit. The traditional proportional–integral–derivative control has been proven not sufficient and capable for this particular petro-chemical process. The advanced control is formed by integrating a predictive functional controller with a traditional proportional–integral–derivative controller in cascade architecture with a feed-forward compensator designated for disturbance rejection. The advanced control system is implemented in a Yokogawa CS3000 integrated production control system. The application results indicate that the advanced control can significantly improve the performance of the delayed coking furnace unit in terms of the outlet temperature of furnace and oxygen concentration of the chimney.
Glycosyltransferase-mediated Sweet Modification in Oral Streptococci
Authors: Zhu F. , Zhang H. , Wu H.
Published: March 2015

Bacterial glycosyltransferases play important roles in bacterial fitness and virulence. Oral streptococci have evolved diverse strategies to survive and thrive in the carbohydrate-rich oral cavity. In this review, we discuss 2 important biological processes mediated by 2 distinct groups of glycosyltransferases in oral streptococci that are important for bacterial colonization and virulence. The first process is the glycosylation of highly conserved serine-rich repeat adhesins by a series of glycosyltransferases. Using Streptococcus parasanguinis as a model, we highlight new features of several glycosyltransferases that sequentially modify the serine-rich glycoprotein Fap1. Distinct features of a novel glycosyltransferase fold from a domain of unknown function 1792 are contrasted with common properties of canonical glycosyltransferases. The second biological process we cover is involved in building sticky glucan matrix to establish cariogenic biofilms by an important opportunistic pathogen Streptococcus mutans through the action of a family of 3 glucosyltransferases. We focus on discussing the structural feature of this family as a glycoside hydrolase family of enzymes. While the 2 processes are distinct, they all produce carbohydrate-coated biomolecules, which enable bacteria to stick better in the complex oral microbiome. Understanding the making of the sweet modification presents a unique opportunity to develop novel antiadhesion and antibiofilm strategies to fight infections by oral streptococci and beyond.
Impact of Employment and Age on Quality of Life of Individuals With Disabilities
Authors: Ra Young-An , Kim Won Ho
Published: March 2015

The purposes of this study are (a) to explore how people with disabilities (PWD) experience differences in their quality of life (QOL) over the course of their lives, (b) to examine the effect of employment on QOL, and (c) to investigate the impact of age on overall QOL for PWD both inter- and intra-individually. To address these aims, this study used the data set for the Panel Survey of Employment for the Disabled (PSED) collected by the Korean Employment Agency for the Disabled (KEAD). The target populations of the study were 5,092 registered persons with disability. No longitudinal approach to examine the impact of employment and age on QOL for individuals with disabilities has been considered in the previous literature. Thus, multilevel modeling was used to examine the relationship between employment, age, and QOL for PWD. Results of this study indicated that employment status and age were significant predictors of QOL among PWD. These findings call attention for the need to consider the impact of employment and age on QOL of PWD both inter- and intra-individually.
The Effects of Financial Vulnerability and Mothers’ Emotional Distress on Child Social, Emotional and Behavioural Well-Being: A Structural Equation Model
Authors: Treanor Morag
Published: March 2015

This article aims to understand the pathways through which financial vulnerability affects children’s social, emotional and behavioural (SEB) well-being and whether that impact is directly experienced or, as hypothesised, indirectly through their mothers’ emotional well-being. It uses data from Growing Up in Scotland – a longitudinal birth cohort study of 5217 children born in 2004–2005. The results show that maternal emotional distress is strongly associated with financial vulnerability, more so than with income, and that child SEB well-being is negatively associated with financial vulnerability and maternal emotional distress, with two-thirds of the effect of financial vulnerability being experienced indirectly through maternal emotional distress. While the qualitative evidence shows that financial vulnerability adversely affects older children directly, through the comparisons they make to their reference group, the quantitative finding is that young children are also negatively affected but predominantly via the effect of financial vulnerability on their mothers’ emotional distress.
Thoreau and the Politics of Ordinary Actions
Authors: Plotica Luke Philip
Published: March 2015

Many regard Henry David Thoreau as an apolitical or even antipolitical thinker, concerned above all with his personal moral purity, and thus unresponsive and irresponsible towards the society in which he lived. Contrary to this received interpretation, I argue that Thoreau’s life and work articulates a robust and complex doctrine of intersubjective responsibility and political agency. Although he denies individual responsibility to institutions and other persons, he soberly embraces individual responsibility for one’s role in shaping and maintaining the arrangements of society, including those that compromise the self and lend support to vicious practices and institutions. In respect of his understanding of responsibility, both his strident critique of modern society and his committed individualism appear as political postures especially apt for late modern times.
Mediated missions: The gospel according to women
Authors: Frederick Marla
Published: March 2015

Women televangelists from the US have garnered a significant following among people in various parts of the world, including Europe, Latin America, Africa and Asia. This paper looks at the influence of female televangelists, Juanita Bynum, Joyce Meyer and Paula White in Kingston, JA. Based upon ethnographic research in Jamaica, I argue that women televangelists have gained tremendous national and international followings based in part upon sharing their experiences of sexual trauma and redemption. These “gospels of sexual redemption,” should be read in light of popularly discussed gospels of prosperity because the economic changes that have occurred under neoliberal policies and massive urbanization have wreaked havoc on both the social and sexual lives of women. These gospels are thus not mutually exclusive but in many ways interconnected.
Assessing the Reliability and Validity of Television and Game Violence Exposure Measures
Authors: Fikkers Karin M. , Piotrowski Jessica Taylor , Valkenburg Patti M.
Published: March 2015

This study evaluated whether common self-report measures of television and game violence exposure represent reliable and valid measurement tools. Three self-report measures—direct estimates, user-rated favorites, and agency-rated favorites—were assessed in terms of test-retest reliability, criterion validity (their relationship with coded media diaries), and construct validity (their relationship with aggression and gender). A total of 238 adolescents participated in a two-wave survey and completed two media diaries. For game violence, the three self-report measures were reliable and valid. For television violence, only direct estimates achieved test-retest reliability and construct validity. Criterion validity could not be established for the television violence measures because the media diary was not a valid criterion for television violence. Our findings indicate that both direct estimates and favorites are valid measures for game violence, whereas for television violence, only direct estimates are valid. We conclude with a discussion about ways to further improve upon and reconceptualize media violence exposure measurement.
Birchwood biochar as partial carbon black replacement in styrene–butadiene rubber composites
Authors: Peterson Steven C , Chandrasekaran Sriraam R , Sharma Brajendra K
Published: March 2015

Birchwood feedstock was used to make slow pyrolysis biochar that contained 89% carbon and <2% ash. This biochar was blended with carbon black (CB) as filler for styrene–butadiene rubber (SBR). Composites made from blended fillers of 25/75 biochar/CB were equivalent to or superior to their 100% CB analogs in terms of tensile strength and toughness at all filler concentrations. Composites made with 50/50 biochar/CB were equivalent to or superior to CB composites in tensile strength, elongation, and toughness properties at total filler concentrations up to 30%. These results demonstrate the potential to use renewable birchwood biochar to replace up to half the CB in certain SBR composites.
Resilient observer-based power system stabilizers
Authors: Soliman Hisham M
Published: March 2015

With the development of power system interconnection, low-frequency oscillation is becoming more and more prominent, and may cause instability of power systems. In this paper, two sources of uncertainty are modelled: plant and controller uncertainties. The non-linear dynamics of power systems under wide load variations are represented by a linear model with uncertainty in the form of a norm-bounded structure. The controller uncertainty resulting from resistor tolerance used in practical implementation is also represented by a norm-bounded model. This paper presents the design of resilient power system stabilizers (PSSs). The proposed PSS keeps stability against plant uncertainty and controller gain errors in the form of a linear matrix inequality (LMI)-sufficient condition. In addition to robust stability, the PSS design achieves regional pole placement to control the settling time and damping ratio, and consequently achieves good dynamic performance. The simulation shows that the proposed PSS design is efficient using the power system model and can drastically improve the dynamic performance of a single machine and a multi-machine power system.