bluuebunny/crossref_metadata_2025_split huggingface dataset:
Boundary Layer Dynamics in a Simple Model for Convectively Coupled Gravity Waves
Authors: Waite Michael L. , Khouider Boualem 
Published: February 2009

AbstractA simplified model of intermediate complexity for convectively coupled gravity waves that incorporates the bulk dynamics of the atmospheric boundary layer is developed and analyzed. The model comprises equations for velocity, potential temperature, and moist entropy in the boundary layer as well as equations for the free tropospheric barotropic (vertically uniform) velocity and first two baroclinic modes of vertical structure. It is based on the multicloud model of Khouider and Majda coupled to the bulk boundary layer–shallow cumulus model of Stevens. The original multicloud model has a purely thermodynamic boundary layer and no barotropic velocity mode. Here, boundary layer horizontal velocity divergence is matched with barotropic convergence in the free troposphere and yields environmental downdrafts. Both environmental and convective downdrafts act to transport dry midtropospheric air into the boundary layer. Basic states in radiative–convective equilibrium are found and are shown to be consistent with observations of boundary layer and free troposphere climatology. The linear stability of these basic states, in the case without rotation, is then analyzed for a variety of tropospheric regimes. The inclusion of boundary layer dynamics—specifically, environmental downdrafts and entrainment of free tropospheric air—enhances the instability of both the synoptic-scale moist gravity waves and nonpropagating congestus modes in the multicloud model. The congestus mode has a preferred synoptic-scale wavelength, which is absent when a purely thermodynamic boundary layer is employed. The weak destabilization of a fast mesoscale wave, with a phase speed of 26 m s−1 and coupling to deep convection, is also discussed.
A PDF-Based Microphysics Parameterization for Simulation of Drizzling Boundary Layer Clouds
Authors: Cheng Anning , Xu Kuan-Man 
Published: February 2009

Abstract
Formulating the contribution of subgrid-scale (SGS) variability to microphysical processes in boundary layer and deep convective cloud parameterizations is a challenging task because of the complexity of microphysical processes and the lack of subgrid-scale information. In this study, a warm-rain microphysics parameterization that is based on a joint double-Gaussian distribution of vertical velocity, liquid water potential temperature, total water mixing ratio, and perturbation of rainwater mixing ratio is developed to simulate drizzling boundary layer clouds with a single column model (SCM). The probability distribution function (PDF) is assumed, but its parameters evolve according to equations that invoke higher-order turbulence closure. These parameters are determined from the first-, second-, and third-order moments and are then used to derive analytical expressions for autoconversion, collection, and evaporation rates. The analytical expressions show that correlation between rainwater and liquid water mixing ratios of the Gaussians enhances the collection rate whereas that between saturation deficit and rainwater mixing ratios of the Gaussians enhances the evaporation rate. Cases of drizzling shallow cumulus and stratocumulus are simulated with large-eddy simulation (LES) and SCM runs (SCM-CNTL and SCM-M): LES explicitly resolves SGS variability, SCM-CNTL parameterizes SGS variability with the PDF-based scheme, but SCM-M uses the grid-mean profiles to calculate the conversion rates of microphysical processes. SCM-CNTL can well reproduce the autoconversion, collection, and evaporation rates from LES. Comparisons between the two SCM experiments showed improvements in mean profiles of potential temperature, total water mixing ratio, liquid water, and cloud amount in the simulations considering SGS variability. A 3-week integration using the PDF-based microphysics scheme indicates that the scheme is stable for long-term simulations.
On How Hot Towers Fuel the Hadley Cell: An Observational and Modeling Study of Line-Organized Convection in the Equatorial Trough from TOGA COARE
Authors: Fierro Alexandre O. , Simpson Joanne , LeMone Margaret A. , Straka Jerry M. , Smull Bradley F. 
Published: February 2009

AbstractAn airflow trajectory analysis was carried out based on an idealized numerical simulation of the nocturnal 9 February 1993 equatorial oceanic squall line observed over the Tropical Ocean and Global Atmosphere Coupled Ocean–Atmosphere Response Experiment (TOGA COARE) ship array. This simulation employed a nonhydrostatic numerical cloud model, which features a sophisticated 12-class bulk microphysics scheme. A second convective system that developed immediately south of the ship array a few hours later under similar environmental conditions was the subject of intensive airborne quad-Doppler radar observations, allowing observed airflow trajectories to be meaningfully compared to those from the model simulation. The results serve to refine the so-called hot tower hypothesis, which postulated the notion of undiluted ascent of boundary layer air to the high troposphere, which has for the first time been tested through coordinated comparisons with both model output and detailed observations.For parcels originating ahead (north) of the system near or below cloud base in the boundary layer (BL), the model showed that a majority (&gt;62%) of these trajectories were able to surmount the 10-km level in their lifetime, with about 5% exceeding 14-km altitude, which was near the modeled cloud top (15.5 km). These trajectories revealed that during ascent, most air parcels first experienced a quick decrease of equivalent potential temperature (θe) below 5-km MSL as a result of entrainment of lower ambient θe air. Above the freezing level, ascending parcels experienced an increase in θe with height attributable to latent heat release from ice processes consistent with previous hypotheses. Analogous trajectories derived from the evolving observed airflow during the mature stage of the airborne radar–observed system identified far fewer (∼5%) near-BL parcels reaching heights above 10 km than shown by the corresponding simulation. This is attributed to both the idealized nature of the simulation and to the limitations inherent to the radar observations of near-surface convergence in the subcloud layer.This study shows that latent heat released above the freezing level can compensate for buoyancy reduction by mixing at lower levels, thus enabling air originating in the boundary layer to contribute to the maintenance of both local buoyancy and the large-scale Hadley cell despite acknowledged dilution by mixing along updraft trajectories. A tropical “hot tower” should thus be redefined as any deep convective cloud with a base in the boundary layer and reaching near the upper-tropospheric outflow layer.
Critical Roles of the Stratiform Rainfall in Sustaining the Madden–Julian Oscillation: GCM Experiments*
Authors: Fu Xiouhua , Wang Bin 
Published: February 2009

Abstract
This study assesses the impact of stratiform rainfall (i.e., large-scale rainfall) in the development and maintenance of the Madden–Julian oscillation (MJO) in a contemporary general circulation model: ECHAM4 AGCM and its coupled version. To examine how the model MJO would change as the stratiform proportion (the ratio of the stratiform versus total rainfall) varies, a suite of sensitivity experiments has been carried out under a weather forecast setting and with three 20-yr free integrations. In these experiments, the detrainment rates of deep/shallow convections that function as a water supply to stratiform clouds were modified, which results in significant changes of stratiform rainfall.
Both the forecast experiments and long-term free integrations indicate that only when the model produces a significant proportion (≥30%) of stratiform rainfall can a robust MJO be sustained. When the stratiform rainfall proportion becomes small, the tropical rainfall in the model is dominated by drizzle-like regimes with neither eastward-propagating nor northward-propagating MJO being sustained.
It is found that the latent heat release of stratiform rainfall significantly warms up the upper troposphere. The covariability between the heating and positive temperature anomaly produces eddy available potential energy that sustains the MJO against dissipation and also allows the direct interaction between the precipitation heating and large-scale low-frequency circulations, which is critical to the development and maintenance of the MJO. This finding calls for better representations of stratiform rainfall and its connections with the convective component in GCMs in order to improve their simulations of the MJO.
Typhoon Ensemble Prediction System Developed at the Japan Meteorological Agency
Authors: Yamaguchi Munehiko , Sakai Ryota , Kyoda Masayuki , Komori Takuya , Kadowaki Takashi 
Published: February 2009

Abstract
The Japan Meteorological Agency (JMA) Typhoon Ensemble Prediction System (TEPS) and its performance are described. In February 2008, JMA started an operation of TEPS that was designed for providing skillful tropical cyclone (TC) track predictions in both deterministic and probabilistic ways. TEPS consists of 1 nonperturbed prediction and 10 perturbed predictions based on the lower-resolution version (TL319L60) of the JMA Global Spectral Model (GSM; TL959L60) and a global analysis for JMA/GSM. A singular vector method is employed to create initial perturbations. Focusing on TCs in the western North Pacific Ocean and the South China Sea (0°–60°N, 100°E–180°), TEPS runs 4 times a day, initiated at 0000, 0600, 1200, and 1800 UTC with a prediction range of 132 h. The verifications of TEPS during the quasi-operational period from May to December 2007 indicate that the ensemble mean track predictions statistically have better performance as compared with the control (nonperturbed) predictions: the error reduction in the 5-day predictions is 40 km on average. Moreover, it is found that the ensemble spread of tracks is an indicator of position error, indicating that TEPS will be useful in presenting confidence information on TC track predictions. For 2008 when TEPS was in operational use, however, it was also found that the ensemble mean was significantly worse than the deterministic model (JMA/GSM) out to 84 h.
The Role of Moist Processes in the Formation and Evolution of Mesoscale Snowbands within the Comma Head of Northeast U.S. Cyclones
Authors: Novak David R. , Colle Brian A. , McTaggart-Cowan Ron 
Published: February 2009

Abstract
The role of moist processes in regulating mesoscale snowband life cycle within the comma head portion of three northeast U.S. cyclones is investigated using piecewise potential vorticity (PV) inversion, modeling experiments, and potential temperature tendency budgets. Snowband formation in each case occurred along a mesoscale trough that extended poleward of a 700-hPa low. This 700-hPa trough was associated with intense frontogenetical forcing for ascent. A variety of PV evolutions among the cases contributed to midlevel trough formation and associated frontogenesis. However, in each case the induced flow from diabatic PV anomalies accounted for a majority of the midlevel frontogenesis during the band’s life cycle, highlighting the important role that latent heat release plays in band evolution. Simulations with varying degrees of latent heating show that diabatic processes associated with the band itself were critical to the development and maintenance of the band. However, changes in the meso-α-scale flow associated with the development of diabatic PV anomalies east of the band contributed to frontolysis and band dissipation. Conditional stability was reduced near 500 hPa in each case several hours prior to band formation. This stability remained small until band formation, when the stratification generally increased in association with the release of conditional instability. Previous studies have suggested that the dry slot is important for the initial stability reduction at midlevels, but this was not evident for the three banding cases examined. Rather, differential horizontal temperature advection in moist southwest flow ahead of the upper trough was the dominant process that reduced the midlevel conditional stability.
Evolution and Structure of Two Severe Cyclonic Bora Events: Contrast between the Northern and Southern Adriatic
Authors: Horvath Kristian , Ivatek-Šahdan Stjepan , Ivančan-Picek Branka , Grubišić Vanda 
Published: February 2009

Abstract
While statistical analyses and observations show that severe bora with maximum gusts exceeding 40 m s−1 can occur in all parts of the Adriatic, the bora research to date has been mainly focused on the dynamics and structure of severe bora in the northern Adriatic. Examined to a significantly lesser degree is a less predictable counterpart in the southern Adriatic, where the Dinaric Alps are higher, broader, and steeper, and where the upwind bora layer is generally less well defined. Identification of the main differences in the sequence of mesoscale and macroscale events leading to the onset of bora in the northern and southern parts of the eastern Adriatic is of fundamental importance for its forecasting. To this end, presented here is a comparative analysis of the evolution and structure of two typical severe cyclonic bora events—one “northern” (7–8 November 1999) and one “southern” (6–7 May 2005) event. The analysis utilizes airborne, radiosonde, and ground-based observations, as well as the hydrostatic Aire Limitée Adaptation Dynamique Developement International (ALADIN/HR) mesoscale model simulations.
It is shown that the development of a severe bora in both the northern and southern Adriatic is critically dependent on the synoptic setting to create an optimal set of environmental conditions. For severe bora in the northern Adriatic, these conditions include a strong forcing of the northeasterly low-level jet and pronounced discontinuities in the upstreamflow structure that promote layering, such as lower- to midtropospheric inversions and environmental critical levels. The development of severe bora in the southern Adriatic is crucially dependent on the establishment of a considerably deeper upstream layer that is able to overcome the strong blocking potential of the southern Dinaric Alps. While the upstream layering is less pronounced, it is closely tied to the presence of a cyclone in the southern Adriatic or over the southern Balkan peninsula.
The upstream atmospheric layering is shown to strongly modulate bora behavior, and different phases of severe bora, related to the presence or absence of upstream layering, are shown to occur within a single bora episode. Furthermore, the presence of a mountain-parallel upper-level jet aloft appears to impede severe bora development in both the northern and southern Adriatic.
What Factors Influence Attitudes Towards People With Current Depression and Current Mania?
Authors: Wolkenstein Larissa , Meyer Thomas D. 
Published: February 2009

Background: Previous studies have detected different variables influencing the attitude towards mentally ill individuals but they have never addressed mania. Furthermore, it is not known whether the same factors affect attitudes towards individuals experiencing major depressive or manic episodes. Aims: Besides factors such as familiarity with mental illness, we were interested whether vulnerability to psychosis and mood disorders as well as social desirability can affect attitudes towards major depressive episodes and manic episodes. Methods: Subjects were presented with a case vignette describing an individual experiencing either a major depressive episode or a manic episode (n = 188, age 16—34 years). Their attitudes towards that person were assessed. Furthermore, factors potentially influencing these attitudes have been assessed such as personal vulnerability factors (i.e. cyclothymia and magical ideation) and social desirability bias. Results: Familiarity with the phenomenon of mental illness turned out to influence the attitude towards affective episodes, whereas the influence of the other potential predictors such as their own experience of affective or schizotypal symptoms failed to appear to be of significance. Conclusions: Whereas `familiarity' turned out to be a factor positively influencing the attitude towards depression, it turned out to have a rather negative influence on the attitude towards mania. This result could have important implications for anti-stigma campaigns.
Help-Seeking Behaviour of Patients Attending the Psychiatric Service in a Sample of United Arab Emirates Population
Authors: Salem Mohamed Omar , Saleh Bader , Yousef Said , Sabri Sufyan 
Published: February 2009

Background: Many patients suffering from psychiatric disorders seek non-professional care before attending specialized services. Aims: To study the help-seeking behaviour of patients referred to the psychiatric department of Al-Ain Hospital, which is the main university teaching hospital in UAE. Methods: This study was a descriptive cross-sectional epidemiological survey. All new patients attending the psychiatry out-patient clinic at Al-Ain Hospital were screened for nine consecutive months from March to November 2003 inclusive. Results: The sample consisted of 106 patients (52 male; 54 female). Prior to presenting to the psychiatric service, 44.8% consulted faith healers, 31% of whom had had a previous experience with them; 45% reported some improvement but their symptoms recurred later, while 47% reported no improvement. In 8% their symptoms worsened for the current episode. Treatments received were herbal (29.8%) and prayer (70.2%). Of the sample, 43.4% consulted a primary care physician before presenting to the secondary psychiatric care. Conclusion: In this sample a sizable number of patients sought alternative methods of treatment before attending the specialized psychiatric services.
International Schizophrenia Research and the Concept of Patient-Centredness: an Analysis Over Two Decades
Authors: Calton Timothy , Cheetham Anna , D'Silva Karen , Glazebrook Cristine 
Published: February 2009

Background: Patient-centred medicine improves psychological and physiological functioning in chronic illnesses. Aims: To determine to what extent the patient-centred ethos (as exemplified by research addressing subjective experiences) was incorporated into work presented at major international schizophrenia research forums between 1988 and 2004. Method: Whole population-based, retrospective cohort study using abstracts from the International Congress on Schizophrenia Research and the Biennial Winter Workshop on Schizophrenia ( n = 9,284). Comparative analysis using abstracts from the International Society for the Psychological Treatment of Schizophrenia ( n = 992). Patient-centredness was assessed by determining the number of abstracts that primarily addressed participants' subjective experiences. Results: Research was presented from 50 countries globally. European and North American countries produced 8,573 (92%) of the total. Biological research was the main theme of 6,960 (75%) of the abstracts, with psychosocial research constituting less than 5%. One hundred and eighty three (2%) abstracts from the two main conferences addressed subjective experiences, as did 333 (34%) from the comparative analysis. Conclusions: Between 1988 and 2004 research emanating from North American and European countries, together with biologically orientated research, were the most prevalent perspectives on schizophrenia. It appears that research into the subjective experiences of participants has not been as prevalent as more objective accounts of the disorder, suggesting that this research effort has not been patient-centred.
Ethics in goal planning for rehabilitation: a utilitarian perspective
Authors: Levack William MM 
Published: February 2009

Background: Past debate on ethics in goal planning for rehabilitation has tended to focus on tensions that can arise between ethical principles; in particular the principles of autonomy and beneficence. When setting goals, clinicians tend to prioritize the wishes of patients, justifying this from the perspective of maximizing patient autonomy. This is tempered by consideration of what is `realistic' and what the pursuit of `unrealistic goals' might be on patient well-being. Rationale: In this paper it is argued that clinicians also have an ethical obligation to take into account the resource implications of goal planning. Utilitarianism provides one perspective on addressing such issues. A utilitarian approach to goal planning would necessitate a focus on maximizing the benefits of rehabilitation to the whole community served when negotiating goals with individual patients. Critique: Clinicians may, however, have a number of concerns about utilitarianism. One assumption is that the quality of life of people with severe disability will be judged as being intrinsically low, and therefore valued less from a utilitarian perspective. A second assumption is that for people with severe disability the large effort expended in rehabilitation to achieve small gains cannot possibly repay itself in a utilitarian equation, specifically in financial terms. Evidence from the literature however has demonstrated that in fact both of these assumptions are probably false. Conclusion: Rehabilitation professionals should not be hesitant to consider utilitarianism as an ethical framework for rehabilitation. In fact, rehabilitation may well gain if people were to use this approach.
Comment on: Nocturnal Nutritional Supplementation Improves Total Body Protein Status of Patients With Liver Cirrhosis: A Randomized 12‐Month Trial
Authors: Léon Carly D. G. 
Published: February 2009

Patients with liver cirrhosis exhibit early onset of gluconeogenesis after short‐term fasting. This accelerated metabolic reaction to starvation may underlie their increased protein requirements and muscle depletion. A randomized controlled trial was conducted to test the hypothesis that provision of a late‐evening nutritional supplement over a 12‐month period would improve body protein stores in patients with cirrhosis. A total of 103 patients (68 male, 35 female; median age 51, range 28‐74; Child‐Pugh grading: 52A, 31B, 20C) were randomized to receive either daytime (between 0900 and 1900 hours) or nighttime (between 2100 and 0700 hours) supplementary nutrition (710 kcal/day). Primary etiology of liver disease was chronic viral hepatitis (67), alcohol (15), cholestatic (6), and other (15). Total body protein (TBP) was measured by neutron activation analysis at baseline, 3, 6, and 12 months. Total daily energy and protein intakes were assessed at baseline and at 3 months by comprehensive dietary recall. As a percentage of values predicted when well, TBP at baseline was similar for the daytime (85 ± 2[standard error of the mean]%) and nighttime (84 ± 2%) groups. For the nighttime group, significant increases in TBP were measured at 3 (0.38 ± 0.10 kg, P = 0.0004), 6 (0.48 ± 0.13 kg, P = 0.0007), and 12 months (0.53 ± 0.17 kg, P = 0.003) compared to baseline. For the daytime group, no significant changes in TBP were seen. Daily energy and protein intakes at 3 months were higher than at baseline in both groups (P < 0.0001), and these changes did not differ between the groups. Conclusion: Provision of a nighttime feed to patients with cirrhosis results in body protein accretion equivalent to about 2 kg of lean tissue sustained over 12 months. This improved nutritional status may have important implications for the clinical course of these patients. (Hepatology. 2008;48:557‐566.)Plank LD, Gane EJ, Peng S, et al.