scholarly journals Classification of Tropical Precipitating Systems Using Wind Profiler Spectral Moments. Part II: Statistical Characteristics of Rainfall Systems and Sensitivity Analysis

2008 ◽  
Vol 25 (6) ◽  
pp. 898-908 ◽  
Author(s):  
T. Narayana Rao ◽  
N. V. P. Kirankumar ◽  
B. Radhakrishna ◽  
D. Narayana Rao ◽  
K. Nakamura
Keyword(s):  
Wide Spectrum ◽  
Companion Paper ◽  
Statistical Characteristics ◽  
Wind Profiler ◽  
Convective Systems ◽  
Rain Gauges ◽  
Tropical Precipitation ◽  
Precipitation Regimes ◽  
Different Types ◽  
Rainfall Statistics

Abstract An automated precipitation algorithm to classify tropical precipitating systems has been described in a companion paper (Part I). In this paper, the algorithm has been applied to 18 months of lower atmospheric wind profiler measurements to study the vertical structure and statistical features of different types of tropical precipitating systems over Gadanki, India. The shallow precipitation seems to be an important component of tropical precipitation, because it is prevalent for about 23% of the observations, with a rainfall fraction of 16%. As expected, the deep convective systems contribute maximum (60%) to the total rainfall, followed by transition and stratiform precipitation. Nonprecipitating clouds (clouds associated with no surface rainfall) are predominant in transition category, indicating that evaporation of precipitation is significant in this region. The quantitative rainfall statistics in different precipitation regimes are compared and contrasted between themselves and also with those reported at different geographical locations obtained with a wide spectrum of instruments, from rain gauges to profilers and scanning radars. The results herein agree with the reports based on scanning radar measurements but differ from profiler-based statistics. The discrepancies are discussed in light of differences in classification schemes, variation in geographical conditions, etc. The sensitivity of the algorithm on the choice of thresholds for identifying different types of precipitating systems is also examined.

scholarly journals Ecology of Cladocera species from Central America based on subfossil assemblages

2016 ◽  
Vol 1 (1S) ◽  
Author(s):  
Marta Wojewódka ◽  
Edyta Zawisza ◽  
Sergio Cohuo ◽  
Laura Macario-González ◽  
Antje Schwalb ◽  
...  
Keyword(s):  
Species Composition ◽  
Central America ◽  
Wide Spectrum ◽  
Great Majority ◽  
Common Species ◽  
Quantitative Composition ◽  
Habitat Conditions ◽  
Mountain Regions ◽  
Different Types ◽  
Lowland Lakes

<p>Cladocera species composition was analyzed in surface sediments of 29 lakes in Central America (Guatemala, El Salvador and Honduras). The material studied was collected with an Ekman grab in autumn 2013 from lakes located in lowland, highland and mountain regions. The study revealed high variability in qualitative and quantitative composition of subfossil Cladocera. A total of 31 Cladocera species (5 planktonic and 26 littoral) were identified, as well as 4 morphotypes that could not be identified (NRR<em> </em>1-4). Planktonic Bosminidae<em> </em>and<em> </em>Daphniidae were the most abundant families. Daphniidae were restricted to water bodies in mountain regions, whereas Bosminidae were widely distributed in lakes with different abiotic conditions. Moreover, Bosminidae species also occurred in highly mineralized waters (&gt; 900 µS cm<sup>-1</sup>). The great majority of the identified Cladocera species belonged to the littoral family Chydoridae. <em>Chydorus </em>cf.<em> sphaericus</em> was the most common species (found in 20 lakes), which probably reflects its tolerance to a wide spectrum of habitat conditions. Cluster analysis discriminated 6 groups of Cladocera species with a high correlation level within groups (≥0.8), which showed different types of correlation with lake characteristics and environmental variables. Canonical correspondence analysis (CCA) showed that altitude and secondly water electrical conductivity were the most important drivers of Cladocera species composition in the region studied. Furthermore, CCA analysis indicated lowland lakes with low water transparency were also characterized by peculiar species assemblages. <strong></strong></p>

scholarly journals Characteristics of Deep Convective Systems and Initiation during Warm Seasons over China and Its Vicinity

2021 ◽  
Vol 13 (21) ◽  
pp. 4289
Author(s):  
Yang Li ◽  
Yubao Liu ◽  
Yun Chen ◽  
Baojun Chen ◽  
Xin Zhang ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
South China ◽  
Warm Season ◽  
Statistical Characteristics ◽  
The Tibetan Plateau ◽  
Spatiotemporal Resolution ◽  
Convective Systems ◽  
Seasonal And Diurnal Variations ◽  
Deep Convective Systems ◽  
Guizhou Plateau

The spatiotemporal statistical characteristics of warm-season deep convective systems, particularly deep convective systems initiation (DCSI), over China and its vicinity are investigated using Himawari-8 geostationary satellite measurements collected during April-September from 2016 to 2020. Based on a satellite brightness temperature multiple-threshold convection identification and tracking method, a total of 47593 deep convective systems with lifetimes of at least 3 h were identified in the region. There are three outstanding local maxima in the region, located in the southwestern, central and eastern Tibetan Plateau and Yunnan-Guizhou Plateau, followed by a region of high convective activities in South China. Most convective systems are developed over the Tibetan Plateau, predominantly eastward-moving, while those developed in Yunnan-Guizhou Plateau and South China mostly move westward and southwestward. The DSCI occurrences become extremely active after the onset of the summer monsoon and tend to reach a maximum in July and August, with a diurnal peak at 11–13 LST in response to the enhanced solar heating and monsoon flows. Several DCSI hotspots are identified in the regions of inland mountains, tropical islands and coastal mountains during daytime, but in basins, plains and coastal areas during nighttime. DCSI over land and oceans exhibits significantly different sub-seasonal and diurnal variations. Oceanic DCSI has an ambiguous diurnal variation, although its sub-seasonal variation is similar to that over land. It is demonstrated that the high spatiotemporal resolution satellite dataset provides rich information for understanding the convective systems over China and vicinity, particularly the complex terrain and oceans where radar observations are sparse or none, which will help to improve the convective systems and initiation nowcasting.

A Review of Positive and Bipolar Lightning Discharges

2003 ◽  
Vol 84 (6) ◽  
pp. 767-776 ◽  
Author(s):  
V. A. Rakov
Keyword(s):  
Forest Fires ◽  
Return Stroke ◽  
Winter Storms ◽  
Convective Systems ◽  
Lightning Channel ◽  
Different Types ◽  
Mesoscale Convective ◽  
Lightning Discharges ◽  
Cloud To Ground Lightning ◽  
Positive Return

Characteristics of lightning discharges that transport either positive charge or both positive and negative charges to the ground are reviewed. These are termed positive and bipolar lightning discharges, respectively. Different types of positive and bipolar lightning are discussed. Although positive lightning discharges account for 10% or less of global cloud-to-ground lightning activity, there are five situations that appear to be conducive to the more frequent occurrence of positive lightning. These situations include 1) the dissipating stage of an individual thunderstorm, 2) winter thunderstorms, 3) trailing stratiform regions of mesoscale convective systems, 4) some severe storms, and 5) thunderclouds formed over forest fires or contaminated by smoke. The highest directly measured lightning currents (near 300 kA) and the largest charge transfers (hundreds of coulombs or more) are thought to be associated with positive lightning. Two types of impulsive positive current waveforms have been observed. One type is characterized by rise times of the order of 10 μs, comparable to those for first strokes in negative lightning, and the other type is characterized by considerably longer rise times, up to hundreds of microseconds. The latter waveforms are apparently associated with very long, 1–2 km, upward negative connecting leaders. The positive return-stroke speed is of the order of 108 m s−1. Positive flashes are usually composed of a single stroke. Positive return strokes often appear to be preceded by significant in-cloud discharge activity, then followed by continuing currents, and involve long horizontal channels. In contrast to negative leaders, which are always optically stepped when they propagate in virgin air, positive leaders seem to be able to move either continuously or in a stepped fashion. The reported percentage of bipolar flashes in summer storms ranges from 6% to 14% and from 5% to 33% in winter storms. Bipolar lightning discharges are usually initiated by upward leaders from tall objects. It appears that positive and negative charge sources in the cloud are tapped by different upward branches of the bipolar-lightning channel.

Relieving pain on prehospital stage – preliminary study

Ból ◽  
2017 ◽  
Vol 18 (1) ◽  
pp. 37-43
Author(s):  
Kamil Krzyżanowski ◽  
Daniel Ślęzak ◽  
Andrzej Basiński ◽  
Przemysław Żuratyński ◽  
Paulina Buca
Keyword(s):  
Wide Spectrum ◽  
Professional Group ◽  
Medical Documentation ◽  
Medical Procedures ◽  
National Medical ◽  
Different Types ◽  
Long Time ◽  
Preliminary Study ◽  
Medical Teams ◽  
Term Benefit

In last time major changes in the system of National Medical Rescue (Państwowe Ratownictwo Medyczne, PRM) occurred. Changes between the others concerned increasing permissions of medical rescuers. For a long time we discussed wide spectrum of actions and autonomy of this professional group and in latest term benefit package of this group was additionally expanded. Is such a varied list of medical procedures, in it pharmacotherapy, is a proper growth of system is subject at issue. Authors of the article decided to look into selected fragments of actions of the system of Medical Rescue and analyze one of import_ant elements of departure team actions, namely relieving pain of injured after the injury. Asking following questions is justified: Is increasing the pool of permissions caused by depleting previous therapeutical possibilities, or were there other reasons to add changes; Is releasing pain on prehospital level enough? Should the attention be focused on this subject and possibly implement repair procedures and educative? To define issues above, medical documentation of trustees of medical teams on the area of Pomeranian Voivodeship were analyzed. Among all provided documents, the ones in which reason of the call was injury were chosen. Tens of thousands cards with different types of injuries were obtained, insulated, multiple and generalized injuries. In how many cases, the procedure of pain relieving were applied was examined and what medicines were used the most. Unfortunately as seen on the presented statistics, only small percentage of cases there were tries of decreasing complaints of injured despite the wide amount available resources. These preliminary studies show the necessity of inputting repair procedures in terms of relieving the pain of injured after injuries by departure teams of Medical Rescue.

Description of chemical systems by their properties

2008 ◽  
Vol 80 (8) ◽  
pp. 1719-1723
Author(s):  
René Dybkær
Keyword(s):  
Data Transmission ◽  
Clinical Chemistry ◽  
Property Values ◽  
International Organization ◽  
Statistical Characteristics ◽  
International Union ◽  
Chemical Systems ◽  
Different Types ◽  
Correct Data ◽  
Mathematical Characteristics

Proper handling and communication of data on chemical systems require knowledge about the mathematical characteristics of different types of property and the unambiguous representation of singular properties. Using the terminology of the International Organization for Standardization (ISO), the concept "property" is generically divided according to various statistical characteristics of property values. The formatting of representation of dedicated kinds-of-property as elaborated by clinical chemists in the International Union of Pure and Applied Chemistry (IUPAC) and the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) should ensure correct data transmission between laboratory dialects in any chemical discipline.

Theory of Viscoplastic Lubrication: Part 2—Applications

1992 ◽  
Vol 114 (3) ◽  
pp. 477-484 ◽  
Author(s):  
W. R. D. Wilson ◽  
X. B. Huang
Keyword(s):  
Boundary Conditions ◽  
Companion Paper ◽  
Slider Bearing ◽  
Reynolds Equations ◽  
Different Types ◽  
Branching Problem ◽  
Inlet Zone ◽  
Development Methods ◽  
Newtonian Behavior

The Reynolds equations for viscoplastic lubricants can be quite complex, involving multiple branches which depend on the form of the boundary conditions invoked in their development. Methods of visualizing and understanding the branching problem are explored. This information is used, together with the Reynolds equations developed in the companion paper, in analyses of the lubrication of a wide slider bearing and a metalforming inlet zone. The results of these analyses are used to draw general conclusions regarding the influence of different types of non-Newtonian behavior.

scholarly journals Statistical Characteristic of Heavy Rainfall Associated with Typhoons near Taiwan Based on High-Density Automatic Rain Gauge Data

2016 ◽  
Vol 97 (8) ◽  
pp. 1363-1375 ◽  
Author(s):  
Chun-Chieh Wu ◽  
Tzu-Hsiung Yen ◽  
Yi-Hsuan Huang ◽  
Cheng-Ku Yu ◽  
Shin-Gan Chen
Keyword(s):  
Heavy Rainfall ◽  
Extreme Rainfall ◽  
Rain Gauge ◽  
Statistical Characteristics ◽  
Rain Gauge Data ◽  
Mountainous Regions ◽  
Rain Gauges ◽  
Weather Stations ◽  
Central Weather Bureau

Abstract This study utilizes data compiled over 21 years (1993–2013) from the Central Weather Bureau of Taiwan to investigate the statistical characteristics of typhoon-induced rainfall for 53 typhoons that have impacted Taiwan. In this work the data are grouped into two datasets: one includes 21 selected conventional weather stations (referred to as Con-ST), and the other contains all the available rain gauges (250–500 gauges, mostly automatic ones; referred to as All-ST). The primary aim of this study is to understand the potential impacts of the different gauge distributions between All-ST and Con-ST on the statistical characteristics of typhoon-induced rainfall. The analyses indicate that although the average rainfall amount calculated with Con-ST is statistically similar to that with All-ST, the former cannot identify the precipitation extremes and rainfall distribution appropriately, especially in mountainous areas. Because very few conventional stations are located over the mountainous regions, the cumulative frequency obtained solely from Con-ST is not representative. As compared to the results from All-ST, the extreme rainfall assessed from Con-ST is, on average, underestimated by 23%–44% for typhoons approaching different portions of Taiwan. The uneven distribution of Con-ST, with only three stations located in the mountains higher than 1000 m, is likely to cause significant biases in the interpretation of rainfall patterns. This study illustrates the importance of the increase in the number of available stations in assessing the long-term rainfall characteristic of typhoon-associated heavy rainfall in Taiwan.

Rotational Compliance Measurements of a Flexible Plane Structure Using an Attached Beam-like Tip, Part 2: Experimental Study

1997 ◽  
Vol 119 (4) ◽  
pp. 603-608 ◽  
Author(s):  
Y. C. Qu ◽  
L. Cheng ◽  
D. Rancourt
Keyword(s):  
Experimental Study ◽  
Error Analysis ◽  
Numerical Simulations ◽  
Numerical Study ◽  
Companion Paper ◽  
Experimental Measurements ◽  
Frequency Range ◽  
Experimental Assessment ◽  
Different Types ◽  
Modal Behavior

This paper presents an experimental assessment of the Tip Excitation Technique (TET) introduced in a companion paper. The aim of the technique is to measure the rotational compliance of attached plane structures. Following the guidelines established on the basis of a numerical study in the companion paper, experimental measurements were performed on a rectangular plate and results were compared with numerical simulations. The investigation focuses on the general performance of the technique, on the different types of excitation used and on other factors necessary to ensure accurate results. In addition, an error analysis is conducted to demonstrate the sensitivity of the results to biased measurement quantities. It is concluded that the proposed technique can be used in the low to middle frequency range, where relatively strong modal behavior is involved.

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