Excitation of Spiral Bands in Hurricanes by Interaction Between the Symmetric Mean Vortex and a Shearing Environmental Steering Current

1979 ◽  
Vol 36 (7) ◽  
pp. 1226-1235 ◽  
Author(s):  
H. E. Willoughby
Keyword(s):  
Steering Current ◽  
Spiral Bands

A study on the relationship between the rotation of binary typhoons and steering current

1986 ◽  
Vol 3 (1) ◽  
pp. 115-124
Author(s):  
Bao Chenglan ◽  
Ruan Junshi ◽  
Zhu Yaojian
Keyword(s):  
The Relationship ◽  
Steering Current

scholarly journals Spiral Bands in a Simulated Hurricane. Part II: Wave Activity Diagnostics

2003 ◽  
Vol 60 (10) ◽  
pp. 1239-1256 ◽  
Author(s):  
Yongsheng Chen ◽  
Gilbert Brunet ◽  
M. K. Yau
Keyword(s):  
Wave Activity ◽  
Spiral Bands

scholarly journals Design of a 2 GHz Linear-in-dB Variable-Gain Amplifier with 80-dB Gain Range

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Zhengyu Sun ◽  
Yuepeng Yan
Keyword(s):  
Current Gain ◽  
Variable Gain Amplifier ◽  
Current Steering ◽  
Gain Bandwidth ◽  
Broad Bandwidth ◽  
Variable Gain ◽  
Bicmos Technology ◽  
Sige Bicmos ◽  
Bicmos Process ◽  
Steering Current

A broadband linear-in-dB variable-gain amplifier (VGA) circuit is implemented in 0.18 μm SiGe BiCMOS process. The VGA comprises two cascaded variable-gain core, in which a hybrid current-steering current gain cell is inserted in the Cherry-Hooper amplifier to maintain a broad bandwidth while covering a wide gain range. Postlayout simulation results confirm that the proposed circuit achieves a 2 GHz 3-dB bandwidth with wide linear-in-dB gain tuning range from −19 dB up to 61 dB. The amplifier offers a competitive gain bandwidth product of 2805 GHz at the maximum gain for a 110-GHz ftBiCMOS technology. The amplifier core consumes 31 mW from a 3.3 V supply and occupies active area of 280 μm by 140 μm.

I.—Contributions to the Palæontology of the Yorkshire Oolites

1884 ◽  
Vol 1 (6) ◽  
pp. 241-252 ◽  
Author(s):  
Wilfrid H. Hudleston
Keyword(s):  
Wide Angle ◽  
Plate Viii ◽  
Spiral Bands

The group of shells figured on Plate VIII. (excepting Fig. 12, whose position is doubtful) constitute a natural section of turbinate or trochiform species, which should be classed under one and the same genus, or at most only separated subgenerically. They are characterized, for the most part, by a conical spire, having a rather wide angle; are few whorled, separated by a widish suture, and imperforate. The sculpture is rich, consisting of spiral bands of more or less prominence, which sometimes constitute varices, single or double, as the case may be. These spiral bands are usually granulated or tuberculated, and are continued into the base of the shell, which is convex and much produced. Between these spiral bands is a fine system of axial (radial) lines or striæ, sometimes bifid, and probably forming crenulations in connection with the more prominent spiral ornaments.

Effect of tropical cyclone intensity and instability on the evolution of spiral bands

2014 ◽  
Vol 31 (5) ◽  
pp. 1090-1100 ◽  
Author(s):  
Hong Huang ◽  
Yongqiang Jiang ◽  
Zhongyi Chen ◽  
Jian Luo ◽  
Xuezhong Wang
Keyword(s):  
Tropical Cyclone ◽  
Tropical Cyclone Intensity ◽  
Cyclone Intensity ◽  
Spiral Bands

scholarly journals Convection and Rapid Filamentation in Typhoon Sinlaku during TCS-08/T-PARC

2012 ◽  
Vol 140 (9) ◽  
pp. 2806-2817 ◽  
Author(s):  
Hung-Chi Kuo ◽  
Chih-Pei Chang ◽  
Ching-Hwang Liu
Keyword(s):  
Research Laboratory ◽  
Field Experiments ◽  
Deep Convection ◽  
Naval Research ◽  
Upward Motion ◽  
System Research ◽  
Spiral Rainband ◽  
Spiral Bands ◽  
Aircraft Data ◽  
Development And Evolution

Abstract This study examines the convection and rapid filamentation in Typhoon Sinlaku (2008) using the Naval Research Laboratory (NRL) P-3 aircraft data collected during the Tropical Cyclone Structure 2008 (TCS-08) and The Observing System Research and Predictability Experiment (THORPEX) Pacific Asian Regional Campaign (T-PARC) field experiments. The high-resolution aircraft radar and wind data are used to directly compute the filamentation time, to allow an investigation into the effect of filamentation on convection. During the reintensification stage, some regions of deep convection near the eyewall are found in the vorticity-dominated area where there is little filamentation. In some other parts of the eyewall and the outer spiral rainband region, including areas of upward motion, the filamentation process appears to suppress deep convection. However, the magnitude of the suppression differs greatly in the two regions. In the outer spiral band region, which is about 200 km from the center, the suppression is much more effective, such that the ratio of the deep convective regime occurrence over the stratiform regime varies from around 50% (200%) for filamentation time shorter (longer) than 24 min. In the eyewall cloud region where the conditions are conducive to deep convection, the filamentation effect may be quite limited. While effect of filamentation suppression is only about 10%, it is still systematic and conspicuous for filamentation times shorter than 19 min. The results suggest the possible importance of vortex-scale filamentation dynamics in suppressing deep convection and organizing spiral bands, which may affect the development and evolution of tropical cyclones.

First record of the genus Pisinna Monterosato, 1878 (Mollusca, Gastropoda, Anabathridae) from the southwest Atlantic, with description of a new species

Zootaxa ◽  
2004 ◽  
Vol 723 (1) ◽  
pp. 1
Author(s):  
FRANKLIN NOEL SANTOS ◽  
RICARDO SILVA ABSALÃO
Keyword(s):  
New Species ◽  
Continental Shelf ◽  
First Record ◽  
Brazilian Coast ◽  
Southwest Atlantic ◽  
First Time ◽  
A New Species ◽  
Spiral Bands

The genus Pisinna Monterosato, 1878 (Anabathridae Ponder, 1988) is reported from the Brazilian coast for the first time. Pisinna bicincta n. sp. is found off Esp rito Santo State (65 67 m depth) on the Brazilian continental shelf. It is diagnosed by its pupiform shell, with subsutural depression, two spiral bands (one white and one orange), dome-shaped paucispiral protoconch sculptured with about 17 spiral rows of minute flat pits, teleoconch with about 22 oblique axial cordlets, and aperture with columellar tooth.

Further Studies of Hurricane Structure by Aircraft Reconnaissance *

1955 ◽  
Vol 36 (9) ◽  
pp. 459-468 ◽  
Author(s):  
R. H. Simpson ◽  
L. G. Starrett
Keyword(s):  
High Pressure ◽  
Research Data ◽  
Pressure Side ◽  
Micro Structure ◽  
Temperature Distributions ◽  
Circulation Patterns ◽  
Stratocumulus Clouds ◽  
Spiral Rainbands ◽  
Very High ◽  
Spiral Bands

Research data and photographs obtained by aircraft reconnaissance in 1954 have clarified certain details of hurricane structure pertaining to the eye, the spiral rainbands, and circulation patterns. A mound of stratocumulus clouds frequently present in the eye seems to be associated with the storm's circulation center. This “hub-cloud” in the presence of certain temperature distributions points to a level of non-divergence, usually below about 8000 feet, MSL. Analyses of the rainband micro-structure reveal a tendency for a pressure minimum immediately adjacent to and on the high pressure side of the spiral bands. An explanation of this effect is proposed and the role it may play in the formation of parasite circulations or false eyes is suggested. Finally, pictures taken from the airplane flying in the eye of the hurricane show cirrus clouds whose forms clearly establish the existence of a cyclonic indraft at very high levels over the eye.

Verification of JNWP-Unit Hurricane and Typhoon Forecasts for 19591

1961 ◽  
Vol 42 (4) ◽  
pp. 239-248 ◽  
Author(s):  
Lloyd W. Vanderman
Keyword(s):  
Sample Size ◽  
Tropical Cyclones ◽  
Northern Hemisphere ◽  
Numerical Weather Prediction ◽  
Weather Prediction ◽  
Tropical Storms ◽  
Numerical Weather ◽  
One Year ◽  
Steering Current ◽  
Forecasting Techniques

During the 1959 season for tropical storms in the Northern Hemisphere, Joint Numerical Weather Prediction (JNWP) Unit computed operationally one or more forecast tracks for 11 hurricanes and tropical storms and 11 typhoons. The 500-mb barotropic forecast flow with the tropical vortex eliminated from the initial 500-mb analysis was employed as the steering current in obtaining these forecasts. A summary of 1959 forecasts and a table of verification of JNWP hurricane forecasts for the years 1956 through 1959 are presented. The improvement and deterioration in forecasts from one year to the next are discussed in terms of sample size, operational changes, and analysis and forecasting techniques specifically designed for forecasting trajectories of tropical cyclones.

Sign in / Sign up

Export Citation Format

Share Document