bluuebunny/crossref_metadata_2025_split huggingface dataset:
Radar Rainfall Estimation for Ground Validation Studies of the Tropical Rainfall Measuring Mission
Authors: Ciach Grzegorz J. , Krajewski Witold F. , Anagnostou Emmanouil N. , Baeck Mary L. , Smith James A. , McCollum Jeffrey R. , Kruger Anton 
Published: August 2010

Abstract
This study presents a multicomponent rainfall estimation algorithm, based on weather radar and rain gauge network, that can be used as a ground-based reference in the satellite Tropical Rainfall Measuring Mission (TRMM). The essential steps are constructing a radar observable, its nonlinear transformation to rainfall, interpolation to rectangular grid, constructing several timescale accumulations, bias adjustment, and merging of the radar rainfall estimates and rain gauge data. Observations from a C-band radar in Darwin, Australia, and a local network of 54 rain gauges were used to calibrate and test the algorithm. A period of 25 days was selected, and the rain gauges were split into two subsamples to apply cross-validation techniques.
A Z–R relationship with continuous range dependence and a temporal interpolation scheme that accounts for the advection effects is applied. An innovative methodology was used to estimate the algorithm controlling parameters. The model was globally optimized by using an objective function on the level of the final products. This is equivalent to comparing hundreds of Z–R relationships using a uniform and representative performance criterion. The algorithm performance is fairly insensitive to the parameter variations around the optimum. This suggests that the accuracy limit of the radar rainfall estimation based on power-law Z–R relationships has been reached. No improvement was achieved by using rain regime classification prior to estimation.
Inference of Marine Atmospheric Boundary Layer Moisture and Temperature Structure Using Airborne Lidar and Infrared Radiometer Data
Authors: Palm Stephen P. , Hagan Denise , Schwemmer Geary , Melfi S. H. 
Published: August 2010

AbstractA new technique for retrieving near-surface moisture and profiles of mixing ratio and potential temperature through the depth of the marine atmospheric boundary layer (MABL) using airborne lidar and multichannel infrared radiometer data is presented. Data gathered during an extended field campaign over the Atlantic Ocean in support of the Lidar In-space Technology Experiment are used to generate 16 moisture and temperature retrievals that are then compared with dropsonde measurements. The technique utilizes lidar-derived statistics on the height of cumulus clouds that frequently cap the MABL to estimate the lifting condensation level. Combining this information with radiometer-derived sea surface temperature measurements, an estimate of the near-surface moisture can be obtained to an accuracy of about 0.8 g kg−1. Lidar-derived statistics on convective plume height and coverage within the MABL are then used to infer the profiles of potential temperature and moisture with a vertical resolution of 20 m. The rms accuracy of derived MABL average moisture and potential temperature is better than 1 g kg−1 and 1°C, respectively. The method relies on the presence of a cumulus-capped MABL, and it was found that the conditions necessary for use of the technique occurred roughly 75% of the time. The synergy of simple aerosol backscatter lidar and infrared radiometer data also shows promise for the retrieval of MABL moisture and temperature from space.
A Semianalytical Solution to a Diffusion–Deposition–Resuspension Model of Local Contamination
Authors: Zhuang Yahui 
Published: August 2010

AbstractThis note describes a semianalytical solution to a diffusion–deposition–resuspension model. Calculations of the fate of a point contaminant show that the model performs well in representing the individual effects of advection, deposition, and resuspension. Within uncertainties inherent to the model parameters, this model solution can be used for assessing the environmental impact of an initially localized source of contamination.
Modeling Surface Sensible Heat Flux Using Surface Radiative Temperatures in a Simple Urban Area
Authors: Voogt J. A. , Grimmond C. S. B. 
Published: August 2010

Abstract
Sensible heat fluxes over a light industrial area in Vancouver, British Columbia, Canada, are analyzed from observed tower fluxes and modeled using a bulk heat transfer approach. The bulk transfer models are initialized using remotely sensed surface temperatures from both airborne and ground-based observing platforms. The remotely sensed surface temperature, in conjunction with a surface database, is used to create area-weighted temperature estimates representative of the complete urban surface. Sensitivity analyses of the various surface temperature estimates are performed. Estimates of kB−1, the ratio of roughness length of momentum to heat, for this area are in general agreement with theoretical estimates for bluff-rough surfaces and are larger than those documented for vegetated and agricultural surfaces. Back-calculated values do vary depending on the method used to determine surface temperature but vary more with the time of day. Empirical relations derived previously for vegetated surfaces are shown to agree well with the results for a dry urban environment. Approaches based on microscale variability in temperature fields are problematic.
Alongwind Dispersion—A Simple Similarity Formula Compared with Observations at 11 Field Sites and in One Wind Tunnel
Authors: Hanna Steven R. , Franzese Pasquale 
Published: August 2010

Abstract
Observations of alongwind dispersion of clouds were collected from 11 field sites and from one wind tunnel and were used to test simple similarity relations. Because most of the observations consist of concentration time series from fixed monitors, the basic observed variable is σt, the standard deviation of the concentration time series. The observed σts range from 0.3 to 9000 s. The concentration time series observations also allow the travel time t from source to receptor to be estimated, from which the cloud advective speed ue can be determined. Observed ts range from 2 to 40 000 s, and observed ues range from 0.5 to 16 m s−1. The alongwind dispersion coefficient σx is then calculated from ueσt. The resulting σt and σx observations support the similarity relations σt = 0.1t and σx = 2u∗t, where u∗ is friction velocity. About 50% of the observations are within a factor of 2 of these similarity relations.
Parameterization of the Two-Point Velocity Correlation Function in a Two-Particle Lagrangian Stochastic Model and Its Effect on the Prediction of Concentration Variances due to a Line Source
Authors: Cohen J. E. , Reynolds A. M. 
Published: August 2010

Abstract
A Lagrangian stochastic model, in which a new parameterization of the two-point velocity correlation function is included, is investigated. Model simulations of temperature variances caused by a line source in an inhomogeneous wind-tunnel boundary layer are shown to be in good agreement with experimental data. A special limit of the new parameterization that is useful at large distances from the source is discussed in detail. A new technique is introduced that greatly enhances the computational efficiency of an implementation of this limit of the model and that renders long-distance simulations of concentration variances of tracers dispersing from line sources computationally treatable.
Estimating the Refractive Index Structure Parameter () over the Ocean Using Bulk Methods
Authors: Frederickson Paul A. , Davidson Kenneth L. , Zeisse Carl R. , Bendall Charles S. 
Published: August 2010

Abstract
Infrared scintillation measurements were obtained along a 7-km path over San Diego Bay concurrently with meteorological measurements obtained from a buoy at the midpoint of the path. Bulk estimates of the refractive index structure parameter were computed from the buoy data and compared with scintillation-derived values. The bulk estimates agreed well with the scintillation measurements in unstable conditions. In stable conditions the bulk estimates became increasingly higher than the scintillation values as the air–sea temperature difference increased. This disagreement may be due to enhanced wave-induced mixing of the lower atmosphere that decreases the vertical temperature and humidity gradients in stable conditions from the assumed Monin–Obukhov similarity (MOS) theory forms, resulting in bulk values that are too high. The bulk estimates decrease rapidly when the absolute air–sea temperature difference approaches small positive values. These predicted decreases in were not observed in either the path-averaged scintillation measurements or in single-point turbulence measurements, indicating that bulk models for estimating scalar structure parameters based on mean air–sea scalar differences are not valid when the mean air–sea difference approaches zero. The authors believe that the most promising means toward improving the bulk model is to obtain a better understanding of the MOS functions over the ocean for a wide stability range, and particularly of the role of ocean waves in modifying near-surface vertical gradients and turbulence characteristics.
Fuzzy Categorization of Weather Conditions for Thermal Mapping
Authors: Shao J. 
Published: August 2010

Abstract
Thermal mapping is a technique that uses a vehicle-mounted infrared radiometer to measure the variation of road surface temperature (RST). Conventionally, the technique is conducted under three qualitatively categorized weather conditions: extreme, intermediate, and damped. These three categories represent basic weather patterns and are widely used in thermal mapping. In real-time operation, however, determination of the weather category is hampered by the lack of systematic classification. Furthermore, certain skills and knowledge of both thermal mapping and meteorology are required. As the thermal mapping technique develops in the direction of providing a platform for automatic and dynamic forecasting of RST over an entire road network, it is necessary to have some kind of hands-off, quantitative, systematic, accurate, and fast categorization of weather conditions for thermal mapping. For this purpose, the relationship between the change of weather conditions and variation of RST was analyzed to define a time domain for application of a reliable categorization algorithm. Fuzzy membership functions were then established, based on cloud amount, cloud type, wind speed, and relative humidity, to compose a fuzzy function of weather categorization for thermal mapping. The results of validation for the fuzzy categorization show that the algorithm can become a useful tool for thermal mapping.
An Extended Version of the Richardson Model for Simulating Daily Weather Variables
Authors: Parlange Marc B. , Katz Richard W. 
Published: August 2010

AbstractThe Richardson model is a popular technique for stochastic simulation of daily weather variables, including precipitation amount, maximum and minimum temperature, and solar radiation. This model is extended to include two additional variables, daily mean wind speed and dewpoint, because these variables (or related quantities such as relative humidity) are required as inputs for certain ecological/vegetation response and agricultural management models. To allow for the positively skewed distribution of wind speed, a power transformation is applied. Solar radiation also is transformed to make the shape of its modeled distribution more realistic. A model identification criterion is used as an aid in determining whether the distributions of these two variables depend on precipitation occurrence. The approach can be viewed as an integration of what is known about the statistical properties of individual weather variables into a single multivariate model.As an application, this extended model is fitted to weather data in the Pacific Northwest. To aid in understanding how such a stochastic weather generator works, considerable attention is devoted to its statistical properties. In particular, marginal and conditional distributions of wind speed and solar radiation are examined, with the model being capable of representing relationships between variables in which the variance is not constant, as well as certain forms of nonlinearity.
A Novel Ice-Cloud Retrieval Algorithm Based on the Millimeter-Wave Imaging Radiometer (MIR) 150- and 220-GHz Channels
Authors: Deeter Merritt N. , Evans K. Franklin 
Published: August 2010

Abstract
A novel microwave technique for simultaneously retrieving cirrus ice water path (IWP) and characteristic ice particle size is described. The retrieval algorithm exploits radiance measurements made at 150 and 220 GHz by the airborne Millimeter-Wave Imaging Radiometer (MIR). Other MIR channels additionally are used to test for the presence of liquid clouds and precipitation, which otherwise would have a contaminating effect on the retrievals. Forward radiative transfer modeling was used to generate a two-dimensional retrieval table in which brightness-temperature depressions (relative to clear-sky values) for both microwave channels were recorded as functions of IWP and characteristic particle size for gamma distributions of ice particles. Retrieval errors due to particle shape, size distribution, clear-sky water vapor variability, cirrus-cloud altitude variability, and instrument noise were estimated using Monte Carlo analysis. Particle shape uncertainty is believed to be the dominant source of retrieval error. The technique is demonstrated using MIR data recorded on the National Aeronautics and Space Administration ER-2 aircraft during the Tropical Ocean and Global Atmosphere Coupled Ocean–Atmosphere Response Experiment experiment in the tropical western Pacific Ocean in 1993. The retrieval technique with MIR data is suited only to high-IWP clouds with large ice particles, such as thick frontal cirrus and convective anvils. The general methodology, however, is applicable to higher frequencies that have greatly increased sensitivity to thinner cirrus.
Discrepancy between Gauges and Satellite Estimates of Rainfall in Equatorial Africa
Authors: McCollum Jeffrey R. , Gruber Arnold , Ba Mamoudou B. 
Published: August 2010

AbstractThe Global Precipitation Climatology Project (GPCP) satellite estimates have approximately twice the magnitude of estimates produced from the rain gauges used by the GPCP in central equatorial Africa. Different possible explanations are identified and investigated. The first is that there may not be enough GPCP rain gauges in the area to provide accurate estimates of rainfall for comparisons with satellite estimates. A comparison of the time-averaged GPCP rain gauge estimate with a long-term (over 40 yr) climatology indicates that the GPCP gauge estimates are similar to long-term rainfall averages, suggesting that the GPCP rain gauge analysis is not underestimating rainfall. Two other possible explanations related to the physical properties of the air masses in this region are studied. Evidence from the literature and from estimates of the effective radii of cloud droplets suggests that there may be an abundance of aerosols in central Africa, resulting in an abundance of cloud condensation nuclei, small drops, and inefficient rain processes. The second explanation is that convective clouds forming under dry conditions generally have cloud bases considerably higher than those of clouds forming in moist environments. This leads to an increase in the evaporation rate of the falling rain, resulting in less precipitation reaching the ground. Analysis of the moisture distributions from both the National Centers for Environmental Prediction numerical weather prediction model reanalysis data and the National Aeronautics and Space Administration Water Vapor Project global moisture dataset reveals that the lower troposphere in this region of Africa is relatively dry, which suggests that cloud bases are high.
Nitric Acid–Sea Salt Reactions: Implications for Nitrogen Deposition to Water Surfaces
Authors: Pryor S. C. , Sørensen L. L. 
Published: August 2010

Abstract
Many previous studies have indicated the importance of nitric acid (HNO3) reactions on sea salt particles for flux divergence of HNO3 in the marine surface layer. The potential importance of this reaction in determining the spatial and temporal patterns of nitrogen dry deposition to marine ecosystems is investigated using models of sea spray generation and particle- and gas-phase dry deposition. Under horizontally homogeneous conditions with near-neutral stability and for wind speeds between 3.5 and 10 m s−1, transfer of HNO3 to the particle phase to form sodium nitrate may decrease the deposition velocity of nitrogen by over 50%, leading to greater horizontal transport prior to deposition to the sea surface. Conversely, for wind speeds above 10 m s−1, transfer of nitrogen to the particle phase would increase the deposition rate and hence decrease horizontal transport prior to surface removal.
Differential activation of the middle-temporal complex to visual stimulation in migraineurs
Authors: Antal Andrea , Polania Rafael , Saller Katharina , Morawetz Carmen , Schmidt-Samoa Carsten , Baudewig Jürgen , Paulus Walter , Dechent Peter 
Published: August 2010

Objective: Differences between people with and without migraine on various measures of visual perception have been attributed to abnormal cortical processing due to the disease. The aim of the present study was to explore the dynamics of the basic interictal state with regard to the extrastriate, motion-responsive middle temporal area (MT-complex) with functional magnetic resonance imaging (fMRI) at 3 tesla using coherent/incoherent moving dot stimuli. Method: Twenty-four migraine patients (12 with aura [MwA], 12 without aura [MwoA]) and 12 healthy subjects participated in the study. The individual cortical folding pattern was accounted for by using a cortical matching approach. Results: In the inferior-posterior portion of the MT-complex, most likely representing MT, control subjects showed stronger bilateral activation compared to MwA and MwoA patients. Compared with healthy controls MwoA and MwA patients showed significantly stronger activation mainly at the left side in response to visual stimulation in the superior-anterior portion of the MT-complex, representing the medial-superior temporal area (MST). Conclusion: Our findings strengthen the hypothesis that hyperresponsiveness of the visual cortex in migraine goes beyond early visual areas, even in the interictal period.
Cardiovascular risk factors associated with migraine among the elderly with a low income: The São Paulo Ageing & Health Study (SPAH)
Authors: Benseñor Isabela M , Goulart Alessandra C , Lotufo Paulo A , Menezes Paulo R , Scazufca Márcia 
Published: August 2010

Background: To investigate the association between cardiovascular risk-factor profile and migraine in the elderly, we evaluated a population sample of ageing men and women (65 years or more) living in a low-income area in the city of São Paulo, Brazil. Patients and Methods: We investigated migraine status and cardiovascular profile from a baseline of 1450 participants (65–102 years of age) of the São Paulo Ageing & Health Study (SPAH), a longitudinal population-based study with low-income elderly in Brazil. The following age and sex-adjusted cardiovascular risk factors were analyzed: blood pressure, pulse pressure, serum total and high-density lipoprotein cholesterol, body mass index, smoking, history of hypertension, diabetes and the 10-year risk of myocardial infarction or coronary heart disease death based on the Framingham Risk Score. Results: The overall prevalence of migraine was 11.4%, and it was 3 times more frequent among women than men (15.3% vs 5.4%; P < 0.0001). Migraineurs were younger than non-migraineurs (mean age 70.6 years vs 72.1 years; P = 0.001, respectively). There was no statistically significant difference regarding the cardiovascular risk-factor profile after adjustment for age and sex among migraineurs and non-migraineurs. Only a decrease in the risk of hypertension among women (OR 0.58; 95% CI 0.38–0.90; P = 0.01) was also observed even after adjustment for age. Conclusions: Overall, we did not find a worse cardiovascular risk profile among elderly migraineurs. An inverse association between hypertension and migraine in women warrants further investigation.
Prospective alpha allocation in the clarification of optimal anticoagulation through genetics (COAG) trial
Authors: Joo Jungnam , Geller Nancy L , French Benjamin , Kimmel Stephen E , Rosenberg Yves , Ellenberg Jonas H 
Published: August 2010

Background The Clarification of Optimal Anticoagulation through Genetics (COAG) trial is a large, multicenter, double-blinded, randomized trial to determine whether use of a genotype-guided dosing algorithm (using clinical and genetic information) to initiate warfarin treatment will improve anticoagulation status when compared to a dosing algorithm using only clinical information. Purpose This article describes prospective alpha allocation and balanced alpha allocation for the design of the COAG trial. Methods The trial involves two possibly heterogeneous populations, which can be distinguished by the difference in warfarin dose as predicted by the two algorithms. A statistical approach is detailed, which allows an overall comparison as well as a comparison of the primary endpoint in the subgroup for which sufficiently different doses are predicted by the two algorithms. Methods of allocating alpha for these analyses are given — a prospective alpha allocation and allocating alpha so that the two analyses have equal power, which we call a ‘balanced alpha allocation.’ Results We show how to include an analysis of the primary endpoint in a subgroup as a co-primary analysis. Power can be improved by incorporating the correlation between the overall and subgroup analyses in a prospective alpha allocation approach. Balanced alpha allocation for the full cohort and subgroup tests to achieve the same desired power for both of the primary analyses is discussed in detail. Limitations In the COAG trial, it is impractical to stratify the randomization on subgroup membership because genetic information may not be available at the time of randomization. If imbalances in the treatment arms in the subgroup are found, they will need to be addressed. Conclusions The design of the COAG trial assures that the subgroup in which the largest treatment difference is expected is elevated to a co-primary analysis. Incorporating the correlation between the full cohort and the subgroup analyses provides an improvement in power for the subgroup comparison, and further improvement may be achieved via a balanced alpha allocation approach when the parameters involved in the sample size calculation are reasonably well estimated. Clinical Trials 2010; 7: 597—604. http://ctj.sagepub.com