scholarly journals Statistical Models of Holland Pressure Profile Parameter and Radius to Maximum Winds of Hurricanes from Flight-Level Pressure and H*Wind Data

2008 ◽  
Vol 47 (10) ◽  
pp. 2497-2517 ◽  
Author(s):  
Peter J. Vickery ◽  
Dhiraj Wadhera
Keyword(s):  
Gulf Of Mexico ◽  
Statistical Models ◽  
Pressure Profile ◽  
Central Pressure ◽  
Wind Fields ◽  
Strong Negative Correlation ◽  
Positive Correlation ◽  
Additional Information ◽  
Hurricane Wind ◽  
Data Incorporate

Abstract In many hurricane risk models the inclusion of the Holland B parameter plays an important role in the risk prediction methodology. This paper presents an analysis of the relationship between B and a nondimensional intensity parameter. The nondimensional parameter includes the strong negative correlation of B with increasing hurricane size [as defined by the radius to maximum winds (RMW)] and latitude as well as a positive correlation with sea surface temperature. A weak positive correlation between central pressure deficit and B is also included in the single parameter term. Alternate statistical models relating B to RMW and latitude are also developed. Estimates of B are derived using pressure data collected during hurricane reconnaissance flights, coupled with additional information derived from the Hurricane Research Division’s H*Wind snapshots of hurricane wind fields. The reconnaissance data incorporate flights encompassing the time period 1977 through 2001, but the analysis was limited to include only those data collected at the 700-hPa-or-higher level. Statistical models relating RMW to latitude and central pressure derived from the dataset are compared to those derived for U.S. landfalling storms during the period 1900–2005. The authors find that for the Gulf of Mexico, using only the landfall hurricanes, the data suggest that there is no inverse relationship between RMW and the central pressure deficit. The RMW data also demonstrate that Gulf of Mexico hurricanes are, on average, smaller than Atlantic Ocean hurricanes. A qualitative examination of the variation of B, central pressure, and radius to maximum winds as a function of time suggests that along the Gulf of Mexico coastline (excluding southwest Florida), during the final 6–24 h before landfall, the hurricanes weaken as characterized by both an increase in central pressure and the radius to maximum winds and a decrease in B. This weakening characteristic of landfalling storms is not evident for hurricanes making landfall elsewhere along the U.S. coastline.

Parametric Adjustments to the Rankine Vortex Wind Model for Gulf of Mexico Hurricanes

2012 ◽  
Vol 134 (4) ◽  
Author(s):  
Chan Kwon Jeong ◽  
Vijay Panchang ◽  
Zeki Demirbilek
Keyword(s):  
Gulf Of Mexico ◽  
Extreme Wave ◽  
Wind Fields ◽  
Wind Model ◽  
Rankine Vortex ◽  
Wave Statistics ◽  
Wind Speeds ◽  
Vortex Model ◽  
Hurricane Wind ◽  
Adjustment Factors

Parametric wind models are often used to reconstruct hurricane wind fields from a limited set of hurricane parameters. Application of the Rankine Vortex and other models used in forecasting Gulf of Mexico hurricanes show considerable differences between the resulting wind speeds and data. The differences are used to guide the development of adjustment factors to improve the wind fields resulting from the Rankine Vortex model. The corrected model shows a significant improvement in the shape, size, and wind speed contours for 14 out of 17 hurricanes examined. The effect on wave fields resulting from the original and modified wind fields are on the order of 4 m, which is important for the estimation of extreme wave statistics.

Relationship of Sense of Coherence to Other Psychosocial Indices

2004 ◽  
Vol 20 (4) ◽  
pp. 227-236 ◽  
Author(s):  
Sara Holmberg ◽  
Anders Thelin ◽  
Eva-Lena Stiernström
Keyword(s):  
Social Support ◽  
Psychosocial Factors ◽  
Sense Of Coherence ◽  
Living Conditions ◽  
Strong Negative Correlation ◽  
Cross Sectional ◽  
Positive Correlation ◽  
Work Related ◽  
Job Demand ◽  
The Mean

Summary: The concept of “sense of coherence” (SOC) has been widely recognized since it was first introduced by Antonovsky. The originality and usefulness of the SOC scale and its relation to other psychosocial measures has been the subject of lively debate. The aim of this paper was to test for associations between SOC and work-related psychosocial factors (mainly the Job Demand-Control model), general living conditions, education, and social network factors. Cross-sectional data from a population-based sample of 1782 rural males from nine counties in Sweden were analyzed with a multiple regression technique. The subjects were occupationally active at inclusion and the mean age was 50 years (range 40-60). SOC was assessed with the original 29-item questionnaire. Psychosocial variables and lifestyle factors were assessed using questionnaires and structured interviews. The mean SOC among the subjects was 152.3 (standard deviation, 19.4). A strong negative correlation was found between SOC and job demand, whereas a positive correlation with job control was demonstrated. A positive correlation with general living conditions and with social support was also found. However, there was no correlation to education and occupation. Thus, SOC was shown to be strongly correlated to work-related psychosocial factors and social support, but independent of sociodemographic factors.

scholarly journals Spatial Variation of the Relationship between PM2.5Concentrations and Meteorological Parameters in China

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
Gang Lin ◽  
Jingying Fu ◽  
Dong Jiang ◽  
Jianhua Wang ◽  
Qiao Wang ◽  
...  
Keyword(s):  
Negative Correlation ◽  
Meteorological Parameters ◽  
Semiarid Region ◽  
Strong Positive Correlation ◽  
Annual Average ◽  
Strong Negative Correlation ◽  
Positive Correlation ◽  
Humid Region ◽  
The Relationship ◽  
Warm Temperate

Epidemiological studies around the world have reported that fine particulate matter (PM2.5) is closely associated with human health. The distribution of PM2.5concentrations is influenced by multiple geographic and socioeconomic factors. Using a remote-sensing-derived PM2.5dataset, this paper explores the relationship between PM2.5concentrations and meteorological parameters and their spatial variance in China for the period 2001–2010. The spatial variations of the relationships between the annual average PM2.5, the annual average precipitation (AAP), and the annual average temperature (AAT) were evaluated using the Geographically Weighted Regression (GWR) model. The results indicated that PM2.5had a strong and stable correlation with meteorological parameters. In particular, PM2.5had a negative correlation with precipitation and a positive correlation with temperature. In addition, the relationship between the variables changed over space, and the strong negative correlation between PM2.5and the AAP mainly appeared in the warm temperate semihumid region and northern subtropical humid region in 2001 and 2010, with some localized differences. The strong positive correlation between the PM2.5and the AAT mainly occurred in the mid-temperate semiarid region, the humid, semihumid, and semiarid warm temperate regions, and the northern subtropical humid region in 2001 and 2010.

scholarly journals A Basin- to Channel-Scale Unstructured Grid Hurricane Storm Surge Model Applied to Southern Louisiana

2008 ◽  
Vol 136 (3) ◽  
pp. 833-864 ◽  
Author(s):  
Joannes J. Westerink ◽  
Richard A. Luettich ◽  
Jesse C. Feyen ◽  
John H. Atkinson ◽  
Clint Dawson ◽  
...  
Keyword(s):  
Storm Surge ◽  
Unstructured Grid ◽  
River Flow ◽  
Computational Cost ◽  
Skill Assessment ◽  
Open Boundary ◽  
Wind Fields ◽  
Hurricane Wind ◽  
Hurricane Storm Surge ◽  
Southern Louisiana

Abstract Southern Louisiana is characterized by low-lying topography and an extensive network of sounds, bays, marshes, lakes, rivers, and inlets that permit widespread inundation during hurricanes. A basin- to channel-scale implementation of the Advanced Circulation (ADCIRC) unstructured grid hydrodynamic model has been developed that accurately simulates hurricane storm surge, tides, and river flow in this complex region. This is accomplished by defining a domain and computational resolution appropriate for the relevant processes, specifying realistic boundary conditions, and implementing accurate, robust, and highly parallel unstructured grid numerical algorithms. The model domain incorporates the western North Atlantic, the Gulf of Mexico, and the Caribbean Sea so that interactions between basins and the shelf are explicitly modeled and the boundary condition specification of tidal and hurricane processes can be readily defined at the deep water open boundary. The unstructured grid enables highly refined resolution of the complex overland region for modeling localized scales of flow while minimizing computational cost. Kinematic data assimilative or validated dynamic-modeled wind fields provide the hurricane wind and pressure field forcing. Wind fields are modified to incorporate directional boundary layer changes due to overland increases in surface roughness, reduction in effective land roughness due to inundation, and sheltering due to forested canopies. Validation of the model is achieved through hindcasts of Hurricanes Betsy and Andrew. A model skill assessment indicates that the computed peak storm surge height has a mean absolute error of 0.30 m.

scholarly journals The effects of cardiac rehabilitation on haemodynamic parameters measured by impedance cardiography in patients with coronary artery disease

2020 ◽  
pp. 126-126
Author(s):  
Milovan Stojanovic ◽  
Marina Deljanin-Ilic ◽  
Stevan Ilic ◽  
Dejan Petrovic ◽  
Bojan Ilic
Keyword(s):  
Coronary Artery Disease ◽  
Negative Correlation ◽  
Impedance Cardiography ◽  
Exercise Stress ◽  
Strong Positive Correlation ◽  
Physical Strain ◽  
Strong Negative Correlation ◽  
Positive Correlation ◽  
Strain Tolerance ◽  
Artery Disease

Background / Aim. Well-organized cardiovascular rehabilitation (CVR) reduces cardiovascular burden by influencing cardiovascular risk factors, improving the quality of life and reducing mortality and hospital readmission. However, its effects on hemodynamic status are largely unknown. The aim of our study was to evaluate the influence of three-week CVR program on hemodynamic status and to investigate if there is a correlation between physical strain tolerance and hemodynamic parameters measured by impedance cardiography (ICG) before and after CVR program in patients with coronary artery disease. Methods. Fifty-two patients attended a three-week CVR program. At the beginning and at the end of rehabilitation program laboratory tests, exercise stress tests (EST) and ICG measurements were taken. Results. Patients showed better strain tolerance on the second exercise stress test (EST2) by achieving higher strain level (Z=2,315; p=0,021) and longer duration of test (Z=2,305; p=0,021). There was a strong positive correlation between the level of EST2 and cardiac output (CO) (r=0,538; p<0,001) and stroke volume (SV) (r=0,380; p=0,017) on the second ICG (ICG2). Also, there was a strong negative correlation between EST2 level and systemic vascular resistance (SVR) (r=-0,472; p=0,002) and SVR index (SSVRI) (r=-0,407; p=0,010) on ICG2. There was a strong positive correlation between EST2 duration and CO (r=0.517; p=0.001) as well as between EST2 duration and SV (r=0.340; p=0.034), and a strong negative correlation between EST2 duration and SVR (r=-0.504; p=0.001) as well as between EST2 duration and SVRI (r=-0.448; p=0.004), according to ICG2. Conclusion. Our study showed that a well-designed CVR program can lead to better physical strain tolerance. Furthermore, CVR led to a significant positive correlation between EST and cardiac output as well as between EST and stroke volume measured by ICG. On the other hand, there was a significant negative correlation between EST and vascular related parameters according to ICG at the end of the CVR program.

scholarly journals The Relationship Between Water Quality and Phytoplankton Abundance at The Eastern Part of Segara Anakan Cilacap, Central Java

2019 ◽  
Vol 1 (2) ◽  
pp. 1
Author(s):  
Hasby Ghoni Asiddiqi ◽  
Agatha Sih Piranti ◽  
Erwin Ardli Riyanto
Keyword(s):  
Water Quality ◽  
Negative Correlation ◽  
Physical Factor ◽  
Phytoplankton Abundance ◽  
Chemical Factor ◽  
Strong Negative Correlation ◽  
Positive Correlation ◽  
Central Java ◽  
Primary Producer ◽  
The Relationship

Phytoplankton is the primary producer whose existence depends not only on the nutrient. The eastern part of Segara Anakan waters experienced changes where the decline in quality which received input from organic and inorganic wastes and residential, industrial and factory wastes of Holcim and Pertamina factories. The purpose of this research is to study the water quality and to study the relationship between water quality and abundance of phytoplankton at the eastern part of Segara Anakan. The result showed that Water quality in Segara Anakan waters in the eastern part of Cilacap consists of several parameters that beyond the quality standards according to the Keputusan Menteri Lingkungan Hidup No. 51 of 2004 such as pH, Nitrate, Ammonia, Phosphate, and TSS. Water temperature is a physical factor which has a strong negative correlation with the abundance of phytoplankton, followed by TSS as a physical factor which has a positive correlation. The chemical factor which has a positive correlation with abundance are TDS, Nitrite and pH, followed by Phosphate, Salinity, Ammonia, and Nitrate which has a negative correlation with the abundance of phytoplankton. Key Words: Environmental factor, phytoplankton, Segara Anakan, Spatial variation, temporal variation.

scholarly journals Assessing the Current Generation of Tourniquets

2020 ◽  
Vol 185 (3-4) ◽  
pp. e377-e382
Author(s):  
Shimon Katsnelson ◽  
Jessie Oppenheimer ◽  
Rafi Gerrasi ◽  
Ariel Furer ◽  
Linn Wagnert-Avraham ◽  
...  
Keyword(s):  
Applied Pressure ◽  
Military Medicine ◽  
Pressure Profile ◽  
Strongly Correlated ◽  
Hemorrhage Control ◽  
Strong Negative Correlation ◽  
Life Saving ◽  
Significant Difference ◽  
New Generation ◽  
Better Than

Abstract Introduction Tourniquet application is an urgent life-saving procedure. Previous studies demonstrated several drawbacks in tourniquet design and application methods that limit their efficacy; among them, loose application of the device before windlass twisting is a main pitfall. A new generation of modern combat tourniquets was developed to overcome these pitfalls. The objective of this study was to assess the effectiveness of three new tourniquet designs: the CAT Generation 7 (CAT7), the SAM Extremity Tourniquet (SAM-XT), and the SOF Tactical Tourniquet Wide (SOFTT-W) as well as its correlation to the degree of slack. Materials and Methods The three tourniquet models were applied in a randomized sequence on a HapMed leg tourniquet trainer, simulating an above-the-knee traumatic amputation by 60 military medicine track cadets. Applied pressure, hemorrhage control status, time until the bleeding stopped, estimated blood volume loss, and slack were measured. Results The mean (±SD) pressure applied using the SAM-XT (186 mmHg ±63) or the CAT7 (175 mmHg ±79) was significantly higher compared to the pressure applied by the SOFTT-W (104 mmHg ±101, P &lt; 0.017), with no significant difference between the first two (P &gt; 0.05). Hemorrhage control rate was similar (P &gt; 0.05) with SAM-XT (73.3%) and CAT7 (67.7%), and both were significantly better than the SOFTT-W (35%, P &lt; 0.017). Slack was similar between CAT7 and SAM-XT (5.2 mm ± 3.4 vs. 5 mm ± 3.5, P &gt; 0.05), yet significantly lower compared to the SOFTT-W (9 mm ± 5, P &lt; 0.017). A strong negative correlation was found between slack and hemorrhage control rate (3.2 mm ± 1.5 mm in success vs. 10.5 mm ± 3.4 mm in failure, P &lt; 0.001) and applied pressure (Pearson’s correlation coefficient of −0.83, P &lt; 0.001). Conclusions Both SAM-XT and CAT7 demonstrated a better pressure profile and hemorrhage control rate compared to SOFTT-W, with no significant difference between the two. The better outcome measures were strongly correlated to less slack.

scholarly journals Performance of Recent Multimodel ENSO Forecasts

2012 ◽  
Vol 51 (3) ◽  
pp. 637-654 ◽  
Author(s):  
Michael K. Tippett ◽  
Anthony G. Barnston ◽  
Shuhua Li
Keyword(s):  
Statistical Models ◽  
Lead Time ◽  
Forecast Error ◽  
Error Variance ◽  
Multiple Model ◽  
Dynamical Models ◽  
Additional Information ◽  
Spring Predictability Barrier ◽  
International Research Institute ◽  
The Mean

AbstractThe performance of the International Research Institute for Climate and Society “ENSO forecast plume” during the 2002–11 period is evaluated using deterministic and probabilistic verification measures. The plume includes multiple model forecasts of the Niño-3.4 index for nine overlapping 3-month periods beginning the month following the latest observations. Skills decrease with increasing lead time and are highest for forecasts made after the northern spring predictability barrier for target seasons occurring prior to the forthcoming such barrier. Forecasts are found to verify systematically better against observations occurring earlier than the intended forecast targets, an effect that becomes greater with increasing lead time. During the study period, the mean forecasts of dynamical models appear to slightly (and statistically insignificantly) outperform those of statistical models, representing a subtle shift from earlier studies. The mean forecasts of dynamical models have overall larger anomalies but similar errors to those of statistical models. Intermodel spread is related to forecast error in an average sense with changes in forecast error due to changes in lead and verification season being properly reflected in changes in spread. The intermodel spread underestimates the forecast error variance, to a greater extent for statistical forecasts than for dynamical ones. Year-to-year changes in plume spread provide little additional information relative to climatological ones.

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