bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Climatology of Heat Waves from a Multimillennial Simulation
Authors: Hunt B. G. 
Published: August 2007

Abstract
A 10 000-yr unforced simulation with the Commonwealth Scientific and Industrial Research Organisation (CSIRO) Mark 2 coupled global climatic model has been used to investigate the occurrence of heat waves over the globe. Results are presented for both seasonal (summer mean) and daily heat waves. Geographical distributions of the occurrence rates of these heat waves are shown for various magnitudes of surface temperature anomalies. The heat waves have specific geographical preferences with regions where relatively frequent, intense, and long-lasting heat waves occur. Time series over all 10 000 yr of the heat waves for the selected model grid boxes illustrate the differing temporal variabilities at these locations, as well as identifying the occurrences of extreme heat waves. To this end, the observed European heat wave of 2003 was simulated remarkably well in its overall characteristics; it occurs once in this simulation. Heat waves for various continental locations are shown to occur as isolated spatial and temporal events, and not as part of larger-scale systems over continental-size domains, suggesting stochastic forcing as a contributor to the initiation of the heat waves. Regional plots of selected heat waves at monthly intervals illustrated the considerable spatial variability, progression, and variation in the intensity of the heat waves. Comparison of year-long daily surface temperature anomalies for heat-wave years for simulated and observed conditions at individual model grid boxes indicated substantial agreement, while spatial plots permitted the progress of a short-term heat wave over the United States to be followed. Multidecadal time series plots of intense heat waves also showed basic similarities between the simulation and observations, despite the brevity of the latter. The simulated time series suggest that more extreme heat waves than currently are observed, owing to the brevity of the observations, may be a possibility as a consequence solely of natural variability. An examination of the physical processes associated with a heat wave showed mutually consistent climatic relationships, such that a heat wave was associated with reduced rainfall and consequently reduced soil moisture content, evaporation, and cloud cover, and increased insolation at the surface. These combined changes created the surface temperature increase intrinsic to the heat wave. All heat waves examined for different regions experienced negative rainfall anomalies prior to a heat wave. The cause of these rainfall anomalies was not readily apparent. While an ENSO influence on heat waves is shown to exist in the simulation, not all ENSO events produce heat waves, suggesting that stochastic influences may determine when a major heat wave occurs in conjunction with these events. The limitations of the adequacy of the model ENSO may, however, have had an influence in this regard.
Observational Analysis of the Predictability of Mesoscale Convective Systems
Authors: Jirak Israel L. , Cotton William R. 
Published: August 2007

Abstract
Mesoscale convective systems (MCSs) have a large influence on the weather over the central United States during the warm season by generating essential rainfall and severe weather. To gain insight into the predictability of these systems, the precursor environments of several hundred MCSs across the United States were reviewed during the warm seasons of 1996–98. Surface analyses were used to identify initiating mechanisms for each system, and North American Regional Reanalysis (NARR) data were used to examine the environment prior to MCS development. Similarly, environments unable to support organized convective systems were also investigated for comparison with MCS precursor environments. Significant differences were found between environments that support MCS development and those that do not support convective organization. MCSs were most commonly initiated by frontal boundaries; however, features that enhance convective initiation are often not sufficient for MCS development, as the environment needs also to be supportive for the development and organization of long-lived convective systems. Low-level warm air advection, low-level vertical wind shear, and convective instability were found to be the most important parameters in determining whether concentrated convection would undergo upscale growth into an MCS. Based on these results, an index was developed for use in forecasting MCSs. The MCS index assigns a likelihood of MCS development based on three terms: 700-hPa temperature advection, 0–3-km vertical wind shear, and the lifted index. An evaluation of the MCS index revealed that it exhibits features consistent with common MCS characteristics and is reasonably accurate in forecasting MCSs, especially given that convective initiation has occurred, offering the possibility of usefulness in operational forecasting.
Analysis of Tropical Cyclogenesis in the Western North Pacific for 2000 and 2001*
Authors: Fu Bing , Li Tim , Peng Melinda S. , Weng Fuzhong 
Published: August 2007

Abstract
High-resolution satellite data and NCEP–NCAR reanalysis data are used to analyze 34 tropical cyclone (TC) genesis events in the western North Pacific during the 2000 and 2001 typhoon seasons. Three types of synoptic-scale disturbances are identified in the pregenesis stages. They are tropical cyclone energy dispersions (TCEDs), synoptic wave trains (SWTs) unrelated to preexisting TCs, and easterly waves (EWs). Among the total 34 TC genesis cases, 6 are associated with TCEDs, 11 cases are associated with SWTs, and 7 cases are associated with EWs. The analyses presented herein indicate that the occurrence of a TCED depends on the TC intensity and the background flow, with stronger cyclones and weaker background easterlies being more likely to induce a Rossby wave train. Not all Rossby wave trains would lead to the formation of a new TC. Among the 11 SWT cases, 4 cases are triggered by equatorial mixed Rossby–gravity waves. Cyclogenesis events associated with EWs are identified by the westward propagation of the perturbation kinetic energy and precipitation fields. For all three types of prestorm disturbances, it seems that scale contraction of the disturbances and convergence forcing from the large-scale environmental flow are possible mechanisms leading to the genesis. Further examination of the remaining 10 genesis cases with no significant prior synoptic-scale surface signals suggests three additional possible genesis scenarios: 1) a disturbance with upper-tropospheric forcing, 2) interaction of a preexisting TC with southwesterly monsoon flows, and 3) preexisting convective activity with no significant initial low-level vorticity. Tropical intraseasonal oscillations have a significant modulation on TC formation, especially in 2000.
SHIPS-MI Forecast Analysis of Hurricanes Claudette (2003), Isabel (2003), and Dora (1999)
Authors: Jones Thomas A. , Cecil Daniel J. 
Published: August 2007

Abstract
Three hurricanes, Claudette (2003), Isabel (2003), and Dora (1999), were selected to examine the Statistical Hurricane Intensity Prediction Scheme with Microwave Imagery (SHIPS-MI) forecast accuracy for three particular storm types. This research was conducted using model analyses and tropical cyclone best-track data, with forecasts generated from a dependent sample. The model analyses and best-track data are assumed to be a “perfect” representation of the actual event (e.g., perfect prog assumption). Analysis of intensity change forecasts indicated that SHIPS-MI performed best, compared to operational SHIPS output, for tropical cyclones that were intensifying from tropical storm to hurricane intensity. Passive microwave imagery, which is sensitive to the intensity and coverage of precipitation, improved intensity forecasts during these periods with a positive intensity change contribution resulting from above normal inner-core precipitation. Forecast improvement was greatest for 12–36-h forecasts, where the microwave contribution to SHIPS-MI was greatest. Once a storm reached an intensity close to its maximum potential intensity, as in the case of Isabel and Dora, both SHIPS and SHIPS-MI incorrectly forecast substantial weakening despite the positive contribution from microwave data. At least in Dora’s case, SHIPS-MI forecasts were slightly stronger than those of SHIPS. Other important contributions to SHIPS-MI forecasts were examined to determine their importance relative to the microwave inputs. Inputs related to sea surface temperature (SST) and persistence–climatology proved to be very important to intensity change forecasts, as expected. These predictors were the primary factor leading to the persistent weakening forecasts made by both models for Isabel and Dora. For Atlantic storms (Claudette and Isabel), the contribution from shear also proved important at characterizing the conduciveness of the environment toward intensification. However, the shear contribution was often small as a result of multiple offsetting shear-related predictors. Finally, it was observed that atmospheric parameters not included in SHIPS, such as eddy momentum flux, could substantially affect the intensity, leading to large forecast errors. This was especially true for the Claudette intensity change forecasts throughout its life cycle.
The Environmental and Inner-Core Conditions Governing the Intensity of Hurricane Erin (2001)
Authors: Jones Thomas A. , Cecil Daniel J. , Dunion Jason 
Published: August 2007

Abstract
The evolution of Hurricane Erin (2001) is presented from the perspective of its environmental and inner-core conditions, particularly as they are characterized in the Statistical Hurricane Intensity Prediction Scheme with Microwave Imagery (SHIPS-MI). Erin can be described as having two very distinct periods. The first, which occurred between 1 and 6 September 2001, was characterized by a struggling tropical storm failing to intensify as the result of unfavorable environmental and inner-core conditions. The surrounding environment during this period was dominated by moderate shear and mid- to upper-level dry air, both caused in some part by the presence of a Saharan air layer (SAL). Further intensification was inhibited by the lack of sustained deep convection and latent heating near the low-level center. The authors attribute this in part to negative effects from the SAL. The thermodynamic conditions associated with the SAL were not well sampled by the SHIPS parameters, resulting in substantial overforecasting by both SHIPS and SHIPS-MI. Instead, the hostile conditions surrounding Erin caused its dissipation on 6 September. The second period began on 7 September when Erin re-formed north of the original center. Erin began to pull away from the SAL and moved over 29°C sea surface temperatures, beginning a rapid intensification phase and reaching 105 kt by 1800 UTC 9 September. SHIPS-MI forecasts called for substantial intensification as in the previous period, but this time the model underestimated the rate of intensification. The addition of inner-core characteristics from passive microwave data improved the skill somewhat compared to SHIPS, but still left much room for improvement. For this period, it appears that the increasingly favorable atmospheric conditions caused by Erin moving away from the SAL were not well sampled by SHIPS or SHIPS-MI. As a result, the intensity change forecasts were not able to take into account the more favorable environment.
The Effect of Probabilistic Information on Threshold Forecasts
Authors: Joslyn Susan , Pak Karla , Jones David , Pyles John , Hunt Earl 
Published: August 2007

AbstractThe study reported here asks whether the use of probabilistic information indicating forecast uncertainty improves the quality of deterministic weather decisions. Participants made realistic wind speed forecasts based on historical information in a controlled laboratory setting. They also decided whether it was appropriate to post an advisory for winds greater than 20 kt (10.29 m s−1) during the same time intervals and in the same geographic locations. On half of the forecasts each participant also read a color-coded chart showing the probability of winds greater than 20 kt. Participants had a general tendency to post too many advisories in the low probability situations (0%–10%) and too few advisories in very high probability situations (90%–100%). However, the probability product attenuated these biases. When participants used the probability product, they posted fewer advisories when the probability of high winds was low and they posted more advisories when the probability of high winds was high. The difference was due to the probability product alone because the within-subjects design and counterbalancing of forecast dates ruled out alternative explanations. The data suggest that the probability product improved threshold forecast decisions.
Consensus of Numerical Model Forecasts of Significant Wave Heights
Authors: Woodcock Frank , Greenslade Diana J. M. 
Published: August 2007

Abstract
The operational consensus forecast (OCF) scheme uses past performance to bias correct and combine numerical forecasts to produce an improved forecast at locations where recent observations are available. Here, OCF uses past observations and forecasts of significant wave height from five numerical wave models available in real time at the Australian Bureau of Meteorology. In addition to OCF, different adaptive weighting and forecast combination strategies are investigated. At deep-water sites (ocean depth &gt; 25 m), all of the interpolated raw model forecasts outperformed 24-h persistence and, after bias correction, one model was clearly best. Significant improvements over raw model significant wave height forecasts were achieved by bias correction, linear-regression methods, and combination strategies. The best forecasts were obtained from a “composite of composites” in which models with highly correlated errors were combined before being included in the performance-weighted bias-corrected forecast. This technique slightly outperformed the linear-regression-corrected best model. At shallow-water sites (ocean depth &lt; 25 m), all raw models perform poorly relative to the 24-h persistence. The composited, corrected forecasts significantly improved on raw model significant wave height forecasts but only slightly outperformed the 24-h persistence. The raw models generated unrealistically large biases that tended to be amplified with larger observed values of significant wave height.
A Quantitative Analysis of the Enhanced-V Feature in Relation to Severe Weather
Authors: Brunner Jason C. , Ackerman Steven A. , Bachmeier A. Scott , Rabin Robert M. 
Published: August 2007

Abstract
Early enhanced-V studies used 8-km ground-sampled distance and 30-min temporal-sampling Geostationary Operational Environmental Satellite (GOES) infrared (IR) imagery. In contrast, the ground-sampled distance of current satellite imagery is 1 km for low earth orbit (LEO) satellite IR imagery. This improved spatial resolution is used to detect and investigate quantitative parameters of the enhanced-V feature. One of the goals of this study is to use the 1-km-resolution LEO data to help understand the impact of higher-resolution GOES data (GOES-R) when it becomes available. A second goal is to use the LEO data available now to provide better severe storm information than GOES when it is available. This study investigates the enhanced-V feature observed with 1-km-resolution satellite imagery as an aid for severe weather warning forecasters by comparing with McCann’s enhanced-V study. Therefore, verification statistics such as the probability of detection, false alarm ratio, and critical success index were calculated. Additionally, the importance of upper-level winds to severe weather occurrence will be compared with that of the quantitative parameters of the enhanced-V feature. The main goal is to provide a basis for the development of an automated detection algorithm for enhanced-V features from the results in this study. Another goal is to examine daytime versus nighttime satellite overpass distributions with the enhanced-V feature.
Warm Season Mesoscale Superensemble Precipitation Forecasts in the Southeastern United States
Authors: Cartwright T. J. , Krishnamurti T. N. 
Published: August 2007

Abstract
With current computational limitations, the accuracy of high-resolution precipitation forecasts has limited temporal and spatial resolutions. However, with the recent development of the superensemble technique, the potential to improve precipitation forecasts at the regional resolution exists. The purpose of this study is to apply the superensemble technique to regional precipitation forecasts to generate more accurate forecasts pinpointing exact locations and intensities of strong precipitation systems. This study will determine the skill of a regional superensemble forecast out to 60 h by examining its equitable threat score and its false alarm ratio. The regional superensemble consists of 12–60-h daily quantitative precipitation forecasts from six models. Five are independent operational models, and one comes from the physically initialized Florida State University regional spectral model. The superensemble forecasts are verified during the summer 2003 season over the southeastern United States using merged River Forecast Center stage-IV radar–gauge and satellite analyses. Precipitation forecasts were skillful in outperforming the operational models at all model times. Precipitation results were stratified by time of day to allow detections of the diurnal cycle. As expected, warm season daytime precipitation is commonly forced by convection, which is difficult to accurately model. Major synoptic regimes, including subtropical highs, midlatitude troughs/fronts, and tropical cyclones, were examined to determine the skill of the superensemble under various synoptic conditions.
Non-rational compliance with social norms: sincere and hypocritical
Authors: Gagné Learry 
Published: August 2007

English Jon Elster has suggested that social norm compliance cannot be explained using rational-choice theory alone, as it also involves emotional motivations. We propose to expand on this proposition by adding another extra-rational aspect. According to Pierre Bourdieu, non-rational compliance earns greater group approval than interested compliance. We model this insight by stating that social norms contain an injunction not to comply rationally. The article begins with a study of motivations underlying social norm compliance, including “hypocritical compliance”, or rational compliance disguised as sincere and disinterested. This part is followed by a critique of the “economy of esteem” model. We introduce in the third part the concept of “hypocritical equilibrium”, in which most agents pretend to comply non-rationally while feigning not to notice that most others do the same. This kind of equilibrium is sustained by esteem-seeking and self-deception. The fourth part is an application of our model to dueling norms. We then conclude by looking at alternative models. Our aim is to show that, in social norm compliance, taking motivations seriously can yield explanations that strict rational-choice models cannot produce. French Selon Jon Elster, le conformisme aux normes sociales ne peut pas s’expliquer uniquement par la théorie du choix rationnel, car il met en jeu des motivations de nature émotionnelle. Nous proposons d’aller au delà de cette proposition en y ajoutant un autre aspect en dehors de la rationalité. Pour Pierre Bourdieu, le conformisme non rationnel est mieux accepté par le groupe que le conformisme intéressé. Nous modélisons cette idée en stipulant que les normes sociales contiennent une injonction à ne pas agir de façon rationnelle. L’article commence par une étude des motivations qui sous-tendent le conformisme aux normes sociales, y compris le “conformisme hypocrite”, qui est un conformisme rationnel déguisé en conformisme désintéressé. Nous présentons ensuite une critique du modèle de l’“économie de l’estime”. Dans la troisième partie, nous introduisons le concept d’“équilibre hypocrite”, où la plupart des agents font semblant de se conformer de manière désintéressée tout en ignorant délibérément les comportements semblables d’autrui. Ce genre d’équilibre se maintient par la recherche d’estime et l’illusion sur soi-même. Dans la quatrième partie, nous appliquons notre modèle aux normes régissant le duel, et nous concluons avec un survol de modèles alternatifs. Notre but est de montrer que, dans le champ normatif, prendre les motivations au sérieux peut nous offrir des explications que les modèles rationnels stricts ne peuvent donner.
Réflexions sur la réflexivité en sociologie
Authors: Hamel Jacques 
Published: August 2007

English This article considers the reflexivity that arises from the “individualization of social life,” which is the result of changes in current societies and which, for example, forces sociology to consider its purpose at a new cost. How exactly is individuality to be defined from this perspective? What status is to be conferred on the statements of individuals who are operating in such a framework? Having defined precisely to what reflexivity corresponds, the author seeks to qualify the theses currently held on this topic, as illustrated by the theories of P. Bourdieu and A. Giddens, which provide an opportunity to conceive of common sense as practical knowledge and individuality as the mediation required to attain the social. The reflexivity of sociology is finally addressed in order to show that today, sociological knowledge fuels the practical knowledge that individuals mobilize to make sense, at their own level, of what they are and what they do. French Cet article envisage la réflexivité surgie de l “individualisation de la vie sociale” née des mutations des sociétés actuelles et qui, par exemple, oblige la sociologie à concevoir son objet à nouveaux frais. Comment définir exactement l’individualité dans cette perspective? Quel statut conférer aux propos des individus qui évoluent dans ce cadre? Après avoir cerné ce à quoi correspond exactement la réflexivité, l’auteur cherche à nuancer les thèses en vogue sur le sujet en prenant pour illustration les théories de P. Bourdieu et d’A. Giddens qui lui permettent de concevoir le sens commun comme connaissance pratique et l’individualité comme médiation obligée pour atteindre le social. La réflexivité de la sociologie est finalement abordée afin de montrer que, de nos jours, la connaissance sociologique alimente la connaissance pratique que mobilisent les individus pour, à leur niveau, rendre raison de ce qu’ils sont et de ce qu’ils font.