bluuebunny/crossref_metadata_2025 huggingface dataset:
An Analog Method for Real-Time Forecasting of Summer Monsoon Subseasonal Variability
Authors: Xavier Prince K. , Goswami B. N.
Published: December 2007

A physically based empirical real-time forecasting strategy to predict the subseasonal variations of the Indian summer monsoon up to four–five pentads (20–25 days) in advance has been developed. The method is based on the event-to-event similarity in the properties of monsoon intraseasonal oscillations (ISOs). This two-tier analog method is applied to NOAA outgoing longwave radiation (OLR) pentad averaged data that have sufficiently long records of observation and are available in nearly real time. High-frequency modes in the data are eliminated by reconstructing the data using the first 10 empirical orthogonal functions (EOFs), which together explain about 75% of the total variance. In the first level of the method, the spatial analogs of initial condition pattern are identified from the modeling data. The principal components (PCs) of these spatial analogs, whose evolution history of the latest five pentads matches that of the initial condition pattern, are considered the temporal PC analogs. Predictions are generated for each PC as the average evolution of PC analogs for the given lead time. Predicted OLR values are constructed using the EOFs and predicted PCs. OLR data for 1979–99 are used as the modeling data and independent hindcasts are generated for the period 2000–05. The skill of anomaly predictions is rather high over the central and northern Indian region for lead times of four–five pentads. The phases and amplitude of intraseasonal convective spells are predicted well, especially the long midseason break of 2002 that resulted in large-scale drought conditions. Skillful predictions can be made up to five pentads when started from an active initial state, whereas the limit of useful predictions is about two–three pentads when started from break initial conditions. An important feature of this method is that unlike some other empirical methods to forecast monsoon ISOs, it uses minimal time filtering to avoid any possible endpoint effects and hence may be readily used for real-time applications. Moreover, as the modeling data grow with time as a result of the increased number of observations, the number of analogs would also increase and eventually the quality of forecasts would improve.
Hurricane Katrina (2005). Part I: Complex Life Cycle of an Intense Tropical Cyclone
Authors: McTaggart-Cowan Ron , Bosart Lance F. , Gyakum John R. , Atallah Eyad H.
Published: December 2007

The devastating effects of Hurricane Katrina (2005) on the Gulf Coast of the United States are without compare for natural disasters in recent times in North America. With over 1800 dead and insured losses near $40 billion (U.S. dollars), Katrina ranks as the costliest and one of the deadliest Atlantic hurricanes in history. This study documents the complex life cycle of Katrina, a storm that was initiated by a tropical transition event in the Bahamas. Katrina intensified to a category-1 hurricane shortly before striking Miami, Florida; however, little weakening was observed as the system crossed the Florida peninsula. An analog climatology is used to show that this behavior is consistent with the historical record for storms crossing the southern extremity of the peninsula. Over the warm Gulf of Mexico waters, Katrina underwent two periods of rapid intensification associated with a warm core ring shed by the Loop Current. Between these spinup stages, the storm doubled in size, leading to a monotonic increase in power dissipation until Katrina reached a superintense state on 28 September. A pair of extremely destructive landfalls in Louisiana followed the weakening of the system over shelf waters. Despite its strength as a hurricane, Katrina did not reintensify following extratropical transition. The evolution of the storm’s outflow anticyclone, however, led to a perturbation of the midlatitude flow that is shown in a companion study to influence the Northern Hemisphere over a period of 2 weeks. An understanding of the varied components of Katrina’s complex evolution is necessary for further developing analysis and forecasting techniques as they apply to storms that form near the North American continent and rapidly intensify over the Gulf of Mexico. Given the observed overall increase in Atlantic hurricane activity since the mid-1990s, an enhanced appreciation for the forcings involved in such events could help to mitigate the impact of similar severe hurricanes in the future.
On Near-Diffusion-Free Advection over Spherical Geodesic Grids
Authors: Mittal Rashmi , Upadhyaya H. C. , Sharma Om P.
Published: December 2007

A forward trajectory advection scheme has been designed for its use in an icosahedral–hexagonal grid model. The scheme has been evaluated with two-dimensional test cases: solid-body rotation and deformational flow; both depict important characteristics of atmospheric flows. The main motivation of this study is to achieve good accuracy without using higher-order interpolations in a numerical advection scheme, so that it may become viable in fine-resolution GCMs. The computation of the error norm shows its gradient as constant and the scheme is approximately first-order accurate. The other interesting feature of this study is that its downstream search algorithm reduces the complexity from O(n2) to O(n).
Bayesian Estimation of Stochastic Parameterizations in a Numerical Weather Forecasting Model
Authors: Song Yong , Wikle Christopher K. , Anderson Christopher J. , Lack Steven A.
Published: December 2007

Parameterizations in numerical models account for unresolved processes. These parameterizations are inherently difficult to construct and as such typically have notable imperfections. One approach to account for this uncertainty is through stochastic parameterizations. This paper describes a methodological approach whereby existing parameterizations provide the basis for a simple stochastic approach. More importantly, this paper describes systematically how one can “train” such parameterizations with observations. In particular, a stochastic trigger function has been implemented for convective initiation in the Kain–Fritsch (KF) convective parameterization scheme within the fifth-generation Pennsylvania State University–National Center for Atmospheric Research (Penn State–NCAR) Mesoscale Model (MM5). In this approach, convective initiation within MM5 is modeled by a binary random process. The probability of initiation is then modeled through a transformation in terms of the standard KF trigger variables, but with random parameters. The distribution of these random parameters is obtained through a Bayesian Monte Carlo procedure informed by radar reflectivities. Estimates of these distributions are then incorporated into the KF trigger function, giving a meaningful stochastic (distributional) parameterization. The approach is applied to cases from the International H2O project (IHOP). The results suggest the stochastic parameterization/Bayesian learning approach has potential to improve forecasts of convective precipitation in mesoscale models.
Finescale Vertical Structure and Dynamics of Some Dryline Boundaries Observed in IHOP
Authors: Miao Qun , Geerts Bart
Published: December 2007

Several radar fine lines, all with a humidity contrast, were sampled in the central Great Plains during the 2002 International H2O Project (IHOP). This study primarily uses aircraft and airborne millimeter-wave radar observations to dynamically interpret the presence and vertical structure of these fine lines as they formed within the well-developed convective boundary layer. In all cases the fine line represents a boundary layer convergence zone. This convergence sustains a sharp contrast in humidity, and usually in potential temperature, across the fine line. The key question addressed herein is whether, at the scale examined here (∼10 km), the airmass contrast itself, in particular the horizontal density (virtual potential temperature) difference and resulting solenoidal circulation, is responsible for the sustained convergence and the radar fine line. For the 10 cases examined herein, the answer is affirmative.
Low-Level African Easterly Wave Activity and Its Relation to Atlantic Tropical Cyclogenesis in 2001
Authors: Ross Robert S. , Krishnamurti T. N.
Published: December 2007

This paper provides new information on the low-level (850 hPa) structure and behavior of African easterly waves (AEWs) and relates this information to previous studies. Individual AEWs that occurred during June–September of 2001 are studied by a synoptic approach that employs Hovmöller diagrams, wave track maps, and case studies. The focus is on two AEW regimes in the lower troposphere over North Africa: a dry regime to the north of the African easterly jet (AEJ) coincident with the surface position of the monsoon trough near 20°N, and a wet regime to the south of the jet coincident with the near-equatorial rainbelt near 10°N. The following issues are addressed: the origin of the waves seen in the two wave regimes, relation of the wave activity to the mean positions of the surface monsoon trough and the 600–700-hPa AEJ, collocation of the tracks of the two wave regimes off the African coast, and diversity in low-level wave behavior that includes merging, splitting, and dissipation of the cyclonic vorticity centers associated with the wave troughs. The relationship between the waves following the two tracks is examined as well as the relationship between the low-level wave activity and Atlantic tropical cyclogenesis in 2001. It is shown that the two wave regimes can interact, and that both regimes were instrumental in Atlantic tropical cyclogenesis in 2001.
Interpretation of Adaptive Observing Guidance for Atlantic Tropical Cyclones
Authors: Reynolds C. A. , Peng M. S. , Majumdar S. J. , Aberson S. D. , Bishop C. H. , Buizza R.
Published: December 2007

Adaptive observing guidance products for Atlantic tropical cyclones are compared using composite techniques that allow one to quantitatively examine differences in the spatial structures of the guidance maps and relate these differences to the constraints and approximations of the respective techniques. The guidance maps are produced using the ensemble transform Kalman filter (ETKF) based on ensembles from the National Centers for Environmental Prediction and the European Centre for Medium-Range Weather Forecasts (ECMWF), and total-energy singular vectors (TESVs) produced by ECMWF and the Naval Research Laboratory. Systematic structural differences in the guidance products are linked to the fact that TESVs consider the dynamics of perturbation growth only, while the ETKF combines information on perturbation evolution with error statistics from an ensemble-based data assimilation scheme. The impact of constraining the SVs using different estimates of analysis error variance instead of a total-energy norm, in effect bringing the two methods closer together, is also assessed. When the targets are close to the storm, the TESV products are a maximum in an annulus around the storm, whereas the ETKF products are a maximum at the storm location itself. When the targets are remote from the storm, the TESVs almost always indicate targets northwest of the storm, whereas the ETKF targets are more scattered relative to the storm location and often occur over the northern North Atlantic. The ETKF guidance often coincides with locations in which the ensemble-based analysis error variance is large. As the TESV method is not designed to consider spatial differences in the likely analysis errors, it will produce targets over well-observed regions, such as the continental United States. Constraining the SV calculation using analysis error variance values from an operational 3D variational data assimilation system (with stationary, quasi-isotropic background error statistics) results in a modest modulation of the target areas away from the well-observed regions, and a modest reduction of perturbation growth. Constraining the SVs using the ETKF estimate of analysis error variance produces SV targets similar to ETKF targets and results in a significant reduction in perturbation growth, due to the highly localized nature of the analysis error variance estimates. These results illustrate the strong sensitivity of SVs to the norm (and to the analysis error variance estimate used to define it) and confirm that discrepancies between target areas computed using different methods reflect the mathematical and physical differences between the methods themselves.
The Operational GFDL Coupled Hurricane–Ocean Prediction System and a Summary of Its Performance
Authors: Bender Morris A. , Ginis Isaac , Tuleya Robert , Thomas Biju , Marchok Timothy
Published: December 2007

The past decade has been marked by significant advancements in numerical weather prediction of hurricanes, which have greatly contributed to the steady decline in forecast track error. Since its operational implementation by the U.S. National Weather Service (NWS) in 1995, the best-track model performer has been NOAA’s regional hurricane model developed at the Geophysical Fluid Dynamics Laboratory (GFDL). The purpose of this paper is to summarize the major upgrades to the GFDL hurricane forecast system since 1998. These include coupling the atmospheric component with the Princeton Ocean Model, which became operational in 2001, major physics upgrades implemented in 2003 and 2006, and increases in both the vertical resolution in 2003 and the horizontal resolution in 2002 and 2005. The paper will also report on the GFDL model performance for both track and intensity, focusing particularly on the 2003 through 2006 hurricane seasons. During this period, the GFDL track errors were the lowest of all the dynamical model guidance available to the NWS Tropical Prediction Center in both the Atlantic and eastern Pacific basins. It will also be shown that the GFDL model has exhibited a steady reduction in its intensity errors during the past 5 yr, and can now provide skillful intensity forecasts. Tests of 153 forecasts from the 2004 and 2005 Atlantic hurricane seasons and 75 forecasts from the 2005 eastern Pacific season have demonstrated a positive impact on both track and intensity prediction in the 2006 GFDL model upgrade, through introduction of a cloud microphysics package and an improved air–sea momentum flux parameterization. In addition, the large positive intensity bias in sheared environments observed in previous versions of the model is significantly reduced. This led to the significant improvement in the model’s reliability and skill for forecasting intensity that occurred in 2006.
Estimating Local Memory of Tropical Cyclones through MPI Anomaly Evolution
Authors: Hart Robert E. , Maue Ryan N. , Watson Michael C.
Published: December 2007

This study examines the local memory of atmospheric and oceanic changes associated with a tropical cyclone (TC). The memory is quantified through anomalous maximum potential intensity (MPI) evolution for 20 days prior to the arrival of a TC through 60 days after the TC passage. The local MPI weakens and is not restored to the evolving climatology until well after the TC has departed. Stabilization occurs through warming of the atmosphere and cooling of the ocean surface on different time scales. The time scale of MPI stabilization following TC passage is approximately 30–35 days for a tropical storm to 50–60 days for a category 3–5 hurricane, with significant storm-specific and basin-specific variability. The atmospheric stabilization (warming with respect to SST) begins with TC arrival and continues for approximately 7–10 days after passage, when the troposphere cools below normal. The rewarming of SST and the subsequent rewarming of the atmosphere occurs within approximately 35 days for all intensities, despite a positive (weakened) MPI anomaly through two months. This suggests that the atmosphere retains anomalous warmth beyond what can be attributable to sensible heating from the rewarmed SST. The maintenance of a positive MPI anomaly beyond 35 days is thus attributed to a feedback on larger scales that requires considerable further research. A TC’s passage through a region does not always lead to a weakening of the MPI. In regions poleward of the sharp SST gradient, the MPI one month after TC passage is often several millibars stronger than climatology. There are also mesoscale regions of destabilization one month after TC passage that may result partially from salinity changes driven by oceanic mixing as well as changes in precipitation and evaporation.
A Fourth-Order-Centered Finite-Volume Scheme for Regular Hexagonal Grids
Authors: Miura Hiroaki
Published: December 2007

Fourth-order-centered operators on regular hexagonal grids with the ZM-grid arrangement are described. The finite-volume method is used and operators are defined at hexagonal cell centers. The gradient operator is calculated from 12 surrounding cell center scalars. The divergence operator is defined from 12 surrounding cell corner vectors. A linear combination of local or interpolated values generates cell corner values used to calculate the operators. The flux-divergence operator applies the same cell corner values as those used in the gradient and divergence operators. The fourth-order convergence of the gradient and divergence operators is obtained in numerical tests using sufficiently smooth and differentiable test functions. The flux-divergence operator is formally second-order accurate. However, the results from a cone advection test show that the flux-divergence operator performs better than a commonly used second-order flux-divergence operator. Numerical dispersion and phase error are small because mean wind advection is computed with fourth-order accuracy.
Prediction of the Diurnal Cycle Using a Multimodel Superensemble. Part II: Clouds
Authors: Chakraborty Arindam , Krishnamurti T. N. , Gnanaseelan C.
Published: December 2007

This study addresses the issue of cloud parameterization in general circulation models utilizing a twofold approach. Four versions of the Florida State University (FSU) global spectral model (GSM) were used, including four different cloud parameterization schemes in order to construct ensemble forecasts of cloud covers. Next, a superensemble approach was used to combine these model forecasts based on their past performance. It was shown that it is possible to substantially reduce the 1–5-day forecast errors of phase and amplitude of the diurnal cycle of clouds from the use of a multimodel superensemble. Further, the statistical information generated in the construction of a superensemble was used to develop a unified cloud parameterization scheme for a single model. This new cloud scheme, when implemented in the FSU GSM, carried a higher forecast accuracy compared to those of the individual cloud schemes and their ensemble mean for the diurnal cycle of cloud cover up to day 5 of the forecasts. This results in a 5–10 W m−2 improvement in the root-mean-square error to the upward longwave and shortwave flux at the top of the atmosphere, especially over deep convective regions. It is shown that while the multimodel superensemble is still the best product in forecasting the diurnal cycle of clouds, a unified cloud parameterization scheme, implemented in a single model, also provides higher forecast accuracy compared to the individual cloud models. Moreover, since this unified scheme is an integral part of the model, the forecast accuracy of the single model improves in terms of radiative fluxes and thus has greater impacts on weather and climate time scales. This new cloud scheme will be tested in real-time simulations.
Predictability of Cold Spring Seasons in Europe
Authors: Shongwe Mxolisi E. , Ferro Christopher A. T. , Coelho Caio A. S. , Jan van Oldenborgh Geert
Published: December 2007

The seasonal predictability of cold spring seasons (March–May) in Europe from hindcasts/forecasts of three operational coupled general circulation models (CGCMs) is investigated. The models used in the investigation are the Met Office Global Seasonal Forecast System (GloSea), the ECMWF System-2 (S2), and the NCEP Climate Forecast System (CFS). Using the relative operating characteristic score and the Brier skill score the long-term prediction skill for spring 2-m temperature in the lower quintile (20%) is assessed. Over much of central and eastern Europe the predictive skill is found to be high. The skill of the Met Office GloSea and ECMWF S2 models significantly surpasses that of damped persistence over much of Europe but the NCEP CFS model outperforms this reference forecast only over a small area. The higher potential predictability of cold spring seasons in eastern relative to southwestern Europe can be attributed to snow effects as areas of high skill closely correspond with the climatological snow line, and snow is shown in this paper to be linked to cold spring 2-m temperatures in eastern Europe. The ability of the models to represent snow cover during the melt season is also investigated. The Met Office GloSea and the ECMWF S2 models are able to accurately mimic the observed pattern of monthly snow-cover interannual variability, but the NCEP CFS model predicts too short a snow season. Improvements in the snow analysis and land surface parameterizations could increase the skill of seasonal forecasts for cold spring temperatures.
Hurricane Katrina (2005). Part II: Evolution and Hemispheric Impacts of a Diabatically Generated Warm Pool
Authors: McTaggart-Cowan Ron , Bosart Lance F. , Gyakum John R. , Atallah Eyad H.
Published: December 2007

The landfall of Hurricane Katrina (2005) near New Orleans, Louisiana, on 29 August 2005 will be remembered as one of the worst natural disasters in the history of the United States. By comparison, the extratropical transition (ET) of the system as it accelerates poleward over the following days is innocuous and the system weakens until its eventual demise off the coast of Greenland. The extent of Katrina’s perturbation of the midlatitude flow would appear to be limited given the lack of reintensification or downstream development during ET. However, the slow progression of a strong upper-tropospheric warm pool across the North Atlantic Ocean in the week following Katrina’s landfall prompts the question of whether even a nonreintensifying ET event can lead to significant modification of the midlatitude flow. Analysis of Hurricane Katrina’s outflow layer after landfall suggests that it does not itself make up the long-lived midlatitude warm pool. However, the interaction between Katrina’s anticyclonic outflow and an approaching baroclinic trough is shown to establish an anomalous southwesterly conduit or “freeway” that injects a preexisting tropospheric warm pool over the southwestern United States into the midlatitudes. This warm pool reduces predictability in medium-range forecasts over the North Atlantic and Europe while simultaneously aiding in the development of Hurricanes Maria and Nate. The origin of the warm pool is shown to be the combination of anticyclonic upper-level features generated by eastern Pacific Hurricane Hilary and the south Asian anticyclone (SAA). The hemispheric nature of the connections involved with the development of the warm pool and its injection into the extratropics has an impact on forecasting, since the predictability issue associated with ET in this case involves far more than the potential reintensification of the transitioning system itself.
Comments on “Unusually Long Duration, Multiple-Doppler Radar Observations of a Front in a Convective Boundary Layer”
Authors: Schultz David M.
Published: December 2007

Stonitsch and Markowski perform multiple-Doppler radar analyses of a cold front over Oklahoma and Kansas. Despite their interesting results, their explanations include a number of misconceptions about cold fronts. These misconceptions include the proper interpretation of the frontogenesis function, the role of entrainment versus differential surface sensible heat flux toward weakening the virtual potential temperature gradient across a cold front, a separation of the wind shift from the virtual potential temperature gradient, and the factors that affect the motion of the cold front.
Spatiotemporal Climate Model Validation—Case Studies for MM5 over Northwestern Canada and Alaska
Authors: Herzfeld Ute C. , Drobot Sheldon , Wu Wanli , Fowler Charles , Maslanik James
Published: December 2007

The Western Arctic Linkage Experiment (WALE) is aimed at understanding the role of high-latitude terrestrial ecosystems in the response of the Arctic system to global change through collection and comparison of climate datasets and model results. In this paper, a spatiotemporal approach is taken to compare and validate model results from the fifth-generation Pennsylvania State University–National Center for Atmospheric Research Mesoscale Model (MM5) with commonly used analysis and reanalysis datasets for monthly averages of temperature and precipitation in 1992–2000 and for a study area at 55°–65°N, 160°–110°W in northwestern Canada and Alaska.

Objectives include a quantitative assessment of similarity between datasets and climate model fields, and identification of geographic areas and seasons that are problematic in modeling, with potential causes that may aid in model improvement. These are achieved by application of algebraic similarity mapping, a simple yet effective method for synoptic analysis of many (here, 45) different spatial datasets, maps, and models. Results indicate a dependence of model–data similarity on seasonality, on climate variable, and on geographic location. In summary, 1) similarity of data and models is better for temperature than for precipitation; and 2) modeling of summer precipitation fields, and to a lesser extent, temperature fields, appears more problematic than that of winter fields. The geographic distribution of areas with best and worst agreement shifts throughout the year, with generally better agreement between maps and models in the northeastern and northern inland areas than in topographically complex and near-coastal areas. The study contributes to an understanding of the geographic complexity of the Arctic system and modeling its diverse climate.
The Annual Variation and Closure of the Water Cycle for the Asian Continent
Authors: Shin Ho-Jeong , Chung Il-Ung , Kim Jeong-Woo
Published: December 2007

The goal of the present study is to elucidate and assess the observed closure and annual variations of the water cycles for the Asian continent and its constituent climatic regions. For this purpose, heavy reliance is placed on simulation as well as observational data. The difference between moisture convergence (MC) and runoff (R) is used as an inverse measure of the closure. Areal averages of MC − R are compared between different areas to decide on its scale dependency and also between different climatic regions categorized by Köppen's climate classification to investigate their annual variations. Atmospheric Model Intercomparison Project (AMIP) II standard output data were used for simulation.

The normal annual means of hydrological variables averaged over the Asian continent are similar between the AMIP II ensemble (MOD) data and the observational (OBS) counterparts, even though MOD and OBS do not exactly agree in terms of their respective regions of distinctive features. In the Asian continent, both OBS MC − R and MOD MC − R are small but in the case of OBS the smallness was due to cancellation of two large and opposite MC − Rs for the dry and mesothermal climatic regions. An appraisal of the closure for each climatic regions has been attempted through comparison between MOD MC − R and OBS MC − R. Nevertheless the relatively poor closures in these two climatic regions surely pose a problem for the simulation community.

The mean annual variations of MOD MC and MOD R, averaged for the Asian continent and its climatic regions, respectively, were analyzed for their uncertainty using the Taylor diagram. MOD R in the dry regions and MOD MC in the microthermal and polar regions are unreliable.
Bayesian Change-Point Analysis of Tropical Cyclone Activity: The Central North Pacific Case*
Authors: Chu Pao-Shin , Zhao Xin
Published: December 2007

Bayesian analysis is applied to detect change points in the time series of annual tropical cyclone counts over the central North Pacific. Specifically, a hierarchical Bayesian approach involving three layers—data, parameter, and hypothesis—is formulated to demonstrate the posterior probability of the shifts throughout the time from 1966 to 2002. For the data layer, a Poisson process with gamma distributed intensity is presumed. For the hypothesis layer, a “no change in the intensity” hypothesis and a “single change in the intensity” hypothesis are considered. Results indicate that there is a great likelihood of a change point on tropical cyclone rates around 1982, which is consistent with earlier work based on a simple log-linear regression model. A Bayesian approach also provides a means for predicting decadal tropical cyclone variations. A higher number of tropical cyclones is predicted in the next decade when the possibility of the change point in the early 1980s is taken into account.
Correction of Global Precipitation Products for Orographic Effects
Authors: Adam Jennifer C. , Clark Elizabeth A. , Lettenmaier Dennis P. , Wood Eric F.
Published: December 2007

Underestimation of precipitation in topographically complex regions plagues most gauge-based gridded precipitation datasets. Gauge locations are usually in or near population centers, which tend to lie at low elevations relative to the surrounding terrain. For hydrologic modeling purposes, the resulting bias can result in serious underprediction of observed flows. A hydrologic water balance approach to develop a globally consistent correction for the underestimation of gridded precipitation in mountainous regions is described. The adjustment is based on a combination of the catchment water balances and variations of the Budyko E/P versus/P curve. The method overlays streamflow measurements onto watershed boundaries and then performs watershed water balances to determine “true” precipitation. Rather than relying on a modeled runoff ratio, evaporation is estimated using the Budyko curves. The average correction ratios for each of 357 mountainous river basins worldwide are spatially distributed across the basins and are then interpolated to ungauged areas. Following application of adjustments for precipitation catch deficiencies, the correction ratios are used to scale monthly precipitation from an existing monthly global dataset (1979–99, 0.5° resolution). The correction for orographic effects resulted in a net increase in global terrestrial precipitation of 6.2% (20.2% in orographically influenced regions only) for the 1979–99 climatology. The approach developed here is applicable to any precipitation dataset in regions where good streamflow data exist. As a cautionary note, the correction factors are dataset dependent, and therefore the adjustments are strictly applicable only to the data from which they were derived.
Enacting a Culturally Responsive Curriculum in a Novice Teacher's Classroom
Authors: Bergeron Bette S.
Published: December 2007

Many educators suggest that novice teachers lack the preparation necessary to be successful in today's urban classrooms, particularly when the experiences of those novices are vastly different from their students. However, it can also be suggested that culturally responsive practices have the potential to counteract the “cultural disequilibrium” that many novices encounter. In this narrative case study, the author traces one novice teacher's journey within a diverse, urban classroom. Data from this study suggest that a novice teacher's support systems, administrator, professional development, and the capacity to take risks contribute to his or her effectiveness in the classroom. Implications for teacher educators include providing instructional and experiential modeling of culturally responsive practices, informing preservice teachers of current educational policies and strategies for becoming student advocates, and becoming engaged within schools to support the implementation of induction programs that authentically prepare novices to turn cultural “disequilibrium” into cultural responsivity.
Avoiding “Jim Crow”
Authors: Cassanello Robert
Published: December 2007

The fight against discrimination on public transportation in Florida at the turn of the twentieth century helped to transform black leaders from nineteenth century activists into modern civil rights protesters. Although the movements at the turn of the century and the ones that dominated the South after World War II were not directly connected through a continuum of leadership and institutions, activists in the early twentieth century laid the intellectual and philosophical foundations of the modern civil rights movements. These important protests coincided with increased migration and urbanization of blacks and poor whites in Florida, but also provided that space where the merging of disparate groups of black leaders could communicate and subordinate gender and class demands to race.
Are Women Always More Interpersonally Sensitive Than Men? Impact of Goals and Content Domain
Authors: Hall Judith A. , Schmid Mast Marianne
Published: December 2007

Two studies examined motivation and content domain as possible influences on sex differences in interpersonal sensitivity. Although much research has found women to excel on tasks measuring interpersonal sensitivity, most of the tasks have measured accuracy in female-relevant domains such as emotion. The present studies measured interpersonal sensitivity, defined as accurate recall of another person, for both female-relevant and male-relevant content domains and also included motivational manipulations intended to influence men and women differently. Study 1 measured accuracy of recalling information in a written vignette about a person, and Study 2 measured accuracy of recalling details about an interaction partner. Both studies supported hypotheses about domain specificity and gender-relevant motivation. However, even for male-stereotypic content and for tasks framed to favor men's motivation to perform well, men's accuracy never exceeded women's.
Shared Resources in Industrial Districts: Information, Know-How and Institutions in the Spanish Tile Industry
Authors: Molina-Morales F. Xavier , Martínez-Fernández M. Teresa
Published: December 2007

The aim of this article is to measure the effect of shared resources on individual firm performance. Using the Industrial District as a definition of the interorganizational context, the authors propose a model that includes a set of factors that are associated with the endowment of external resources, that is, collective information and know-how, and involvement in local institutions. To illustrate the theoretical argumentation, they develop an empirical study using a one hundred—firm sample from the Spanish ceramic tile industry to search for a statistical association between resource variables and performance of the firms. Finally, findings of the article suggest that to increase performance, firms must develop a distinct capacity so as to be able to shape and exploit shared or collective resources.
New Estimates of Returns to Scale and Spatial Spillovers for EU Regional Manufacturing, 1986—2002
Authors: Angeriz Alvaro , McCombie John , Roberts Mark
Published: December 2007

This article presents some new estimates of the degree of returns to scale for European regional manufacturing, for the period 1986—2002. To obtain these estimates, the article makes use of a Verdoorn law framework, estimating both demand- and supply-side versions of the law. Estimation is further embedded within a spatial econometric framework that allows for both ``substantive'' and ``nuisance'' sources of spatial autocorrelation. The former arises from cross-regional spillovers in the growth process, while the latter is a result of the use of the administrative NUTS1 definition of regions. Whereas the demand-side version of the Verdoorn law yields estimates of substantial increasing returns, the supply-side version is unable to refute the hypothesis of constant returns. It is argued, however, that the demand-side version is to be preferred on a priori grounds. The article also considers the static-dynamic Verdoorn law paradox and successfully confirms a recently proposed explanation of this paradox.
Comparative Approaches for Assessing Network Vulnerability
Authors: Grubesic Tony H. , Matisziw Timothy C. , Murray Alan T. , Snediker Diane
Published: December 2007

A common theme in analysis and evaluation of network-based critical infrastructure is the assessment of system vulnerability. Graph theoretic, simulation, and optimization-based techniques have played a significant role in examining potential network vulnerabilities given the insights they can provide for mitigating facility loss and prioritizing fortification efforts. Central to these approaches is the concept of facility (arc—node) importance or criticality to system survivability. Assessments of network vulnerability can dramatically differ based on how facility importance is characterized. In this review, various approaches for assessing facility importance and network vulnerability are examined. The key differences in these approaches are the ways in which a facility's role in maintaining network operability is evaluated given arc—node disruption. Comparative results suggest significant differences exist among measures of facility importance and network performance. Furthermore, the subsequent incongruities in these measures and their implications need to be clearly understood to support interdiction risk and vulnerability assessment for critical infrastructures.
A General Equilibrium Assessment of the Impact of a Fall in Tourism Under Alternative Closure Rules: the Case of the Balearic Islands
Authors: Polo Clemente , Valle Elisabeth
Published: December 2007

A look at the 1997 input-output table shows the Balearic Islands as a service-oriented economy, highly specialized in the production of services for tourists. The main goal of this article is to evaluate with alternative multisectoral models the impact on the Balearic Islands economy of a 10 percent permanent fall in tourism demand. First, we estimate the impact of the reduction in nonresident consumption using a rather standard input-output model. Then, we estimate its effects using an extended general linear model implemented with a social accounting matrix elaborated by the authors. Finally, we use an applied (computable) general equilibrium model using alternative closure rules to those encountered in other regional studies.
A Longitudinal Evaluation of Medication Use Among the Old-Old Population in Israel
Authors: Blumstein Tzvia , Shmotkin Dov , Eyal Nitza , Shorek Aviva , Lerner-Geva Liat
Published: December 2007

This study examined patterns and predictors of change in medication use among old-old participants (aged 75 to 94 years) in a three-wave national Israeli study. The findings indicated a significant increase in the number of medications on short-term follow-up (3.6 years) and a modest, marginally significant increase in the long term (11.7 years). The number of medications was predicted by predisposing characteristics and baseline needs of physical and mental health, explaining 20% of the variance in the short- and long-term models. Women, married individuals, and those with low perceived health and low depressive symptoms tended to increase their use in the short term, whereas men, low-income individuals, and those with higher comorbidities and low difficulties in instrumental activity of daily living tended to increase their use in the long term. The leveling of medication use found on long-term follow-up highlights the particular dynamics of health behavior and health care practices relating to the old-old population.
Which Advance Directive Matters? An Analysis of End-of-Life Decisions Made in Nursing Homes
Authors: Cohen-Mansfield Jiska , Lipson Steven
Published: December 2007

This study clarifies the role of advance directives in the process of decision making in nursing homes. Physicians reported on the actual use of advance directives in a medical decision-making process related to status changes in 70 nursing home residents (mean age = 89 years). Charts were also reviewed to assess the specifics of the advance directives. Despite a high prevalence of advance directives, the directives themselves had a very limited role in affecting treatments. The physicians surveyed viewed directives related to hospitalization as the most useful, though these were not the most available directives. The attention and format given to advance directives in the nursing home may need to be reevaluated.
Education and Self-Rated Health
Authors: Mirowsky John , Ross Catherine E.
Published: December 2007

The cumulative advantage hypothesis predicts that the adulthood rate of decline in health differs across levels of education in a manner that progressively enlarges the health gap across most or all of adulthood. The rising importance hypothesis predicts that the differences across levels of education in the rate of health's decline have been growing for many decades. If both are correct, then each phenomenon tends to obscure the other when comparing the health gap across age groups in a particular year or period. The trend also can make it seem that health converges across levels of education in old age when it actually diverges. A latent-growth model of U.S. data from 1995, 1998, and 2001 supported both hypotheses. It also showed a trend toward lower age-specific self-rated health at all levels of education, but less so the higher the education. There was no significant convergence over time in older age groups.
Research in the Biotech Age: Can Informational Privacy Compete?
Authors: Peekhaus Wilhelm
Published: December 2007

This article examines the privacy of personal medical information in the health research context. Arguing that biomedical research in Canada has been caught up in the government's broader neoliberal policy agenda that has positioned biotechnology as a strategic driver of economic growth, the author discusses the tension between informational privacy and the need for medical information for research purposes. Consideration is given to the debate about whether privacy for medical information serves or hinders the “public good” in respect of medical research and to discussions of informed consent as an element of “fair information practices” designed to safeguard the privacy of personal information, including attempts to subvert requirements for informed consent in the medical research context.
Wikisurveillance: A Genealogy of Cooperative Watching in the West
Authors: Arntfield Mike
Published: December 2007

This article interrogates the relationship between technology and law enforcement and how changing police surveillance techniques have influenced Western expectations of privacy from the mid-19th century to the present. By examining the evolution of telecommunications devices in particular, the author identifies a diffuse and publicly inclusive system of collaborative data mining maintained by private citizens—a culture of wikisurveillance—as being a technologically determined consequence of police reforms made in 1829 Britain. From the now extinct police signal box to modern AMBER alerts, technology allows the police to be divested of their public presence as mechanical surveillance responsibilities are willingly usurped by private enterprise and largely unaccountable civilians who collectively coauthor and codify the occidental discourse on privacy. As public and private spaces alike become increasingly subject to internal, unregulated monitoring that mimics the police methodology, this article explores the origins of our present zeitgeist of mediated voyeurism.
Pursuing the Anonymous User: Privacy Rights and Mandatory Registration of Prepaid Mobile Phones
Authors: Gow Gordon A. , Parisi Jennifer
Published: December 2007

In recent years there has been concern among law enforcement and national security organizations about the use of “anonymous” prepaid mobile phone service and its purported role in supporting criminal and terrorist activities. As a result, a number of countries have implemented registration requirements for such service. Privacy rights advocates oppose such regulatory measures, arguing that there is little practical value in attempting to register prepaid mobile devices, and the issue raises important questions about a citizen's entitlement to anonymity in the ownership of a networked communications device. This article provides an overview of the issue and presents findings drawn from a recent study on prepaid mobile phone regulation in the Organisation for Economic Co-operation and Development countries. The article concludes by suggesting that there are significant problems with the claim that mandatory registration of prepaid mobile phone service is a necessary or an effective regulatory course of action.
Closing the Barn Door: The Effect of Parental Supervision on Canadian Children's Online Privacy
Authors: Steeves Valerie , Webster Cheryl
Published: December 2007

Empirical data from a large sample of Canadian youth aged 13 to 17 years suggest that, although the current privacy policy framework is having a positive effect on the extent to which young people are complying with the types of behavior promoted by adults as privacy protective, its primary focus on parental supervision is inadequate to fully protect children's online privacy. Respondents with high levels of either social interaction or identity play are more likely than those with lower levels to divulge personal identifiers and display privacy-risky behavior, independent of their level of parental supervision. High levels of parental supervision, therefore, do not eliminate but merely reduce privacy-risky behaviors associated with social uses of the Internet. As such, parental supervision cannot adequately protect children who have integrated the Net most fully into their social lives, especially given the high premium that children place on the use of the Net to talk to friends and explore social roles.
Relational Support as a Predictor of Identity Status in an Ethnically Diverse Early Adolescent Sample
Authors: Hall Susan P. , Brassard Marla R.
Published: December 2007

The role of relational (i.e., parent, peer, teacher) support as a predictor of identity status was assessed using a sample of 635 early adolescents from an ethnically diverse, low-income school district. Identity status was measured using the Objective Measure of Ego Identity Status. Multivariate regression analyses suggested that parental support predicted higher foreclosure and lower moratorium in White students, higher achievement in Latino/as, and higher diffusion in African Americans. Peer support predicted higher achievement in Whites and African Americans and higher diffusion in African Americans. Findings suggest that relational support may play a greater role in promoting the formation and maintenance of commitments than in the exploration of alternatives. This study also demonstrates that ethnicity is an important factor in identity status research, as significant effects for the relational (particularly parental) support variables varied between the ethnic groups.