Radar Observations of the Effects of Changing Electric Fields on the Orientations of Hydrometeors PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Radar Observations of the Effects of Changing Electric Fields on the Orientations of Hydrometeors PDF full book. Access full book title Radar Observations of the Effects of Changing Electric Fields on the Orientations of Hydrometeors by James I. Metcalf. Download full books in PDF and EPUB format.
Author: James I. Metcalf
Publisher:
ISBN:
Category : Atmospheric electricity
Languages : en
Pages : 44
Get Book Here
Book Description
The changing orientations of hydrometeors due to rapidly changing electric fields in clouds have been observed for the first time at a radar wavelength of 11 cm (S-band) with the polarimetric Doppler radar operated in Sudbury, MA by the Geophysics Directorate of Phillips Laboratory. During 1991 the radar was operated in a half-matrix mode, transmitting a signal of right circular polarization and receiving signals of right and left circular polarization. Observations of electrified storms on nine days during the spring and summer of 1991 revealed several occurrences of lightning that coincided with significant changes of the circular depolarization ratio (CDR), the cross-correlation, or the phase of the cross-covariance of the two received signals. We observed changes up to 2 dB in CDR, 50% in cross-correlation, and 40° in phase. However, many occurrences of lightning observed by radar were not accompanied by detectable changes of hydrometeor orientations, and we did not observe the cyclical changes of the polarimetric quantities that have been observed elsewhere with radars of shorter wavelength. We present examples of our observations and discuss implications for future measurements with this radar.
Author: James I. Metcalf
Publisher:
ISBN:
Category : Atmospheric electricity
Languages : en
Pages : 44
Get Book Here
Book Description
The changing orientations of hydrometeors due to rapidly changing electric fields in clouds have been observed for the first time at a radar wavelength of 11 cm (S-band) with the polarimetric Doppler radar operated in Sudbury, MA by the Geophysics Directorate of Phillips Laboratory. During 1991 the radar was operated in a half-matrix mode, transmitting a signal of right circular polarization and receiving signals of right and left circular polarization. Observations of electrified storms on nine days during the spring and summer of 1991 revealed several occurrences of lightning that coincided with significant changes of the circular depolarization ratio (CDR), the cross-correlation, or the phase of the cross-covariance of the two received signals. We observed changes up to 2 dB in CDR, 50% in cross-correlation, and 40° in phase. However, many occurrences of lightning observed by radar were not accompanied by detectable changes of hydrometeor orientations, and we did not observe the cyclical changes of the polarimetric quantities that have been observed elsewhere with radars of shorter wavelength. We present examples of our observations and discuss implications for future measurements with this radar.
Author: James I. Metcalf
Publisher:
ISBN:
Category : Atmospheric electricity
Languages : en
Pages : 0
Get Book Here
Book Description
Author: James I. Metcalf
Publisher:
ISBN:
Category : Atmospheric electricity
Languages : en
Pages : 38
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category : Environmental geology
Languages : en
Pages : 116
Get Book Here
Book Description
Author: James I. Metcalf
Publisher:
ISBN:
Category : Atmospheric electricity
Languages : en
Pages : 40
Get Book Here
Book Description
In recent years, there has been increased interest in the use of radars to identify electrified clouds and to quantify electrification processes. This report surveys the use of radars to observe lightning and to observe the effects of electrical fields on the orientations of hydrometeors. Observations of lightning channels, conducted with increasing sophistication since the 1940's, have revealed the wavelength dependence of the reflectivity of lightning, the distribution of lightning echoes in storms, and the differential reflectivity of lightning. Observations of electrified clouds with polarization diversity radars during the 1970's and early 1980's revealed changes of orientations of ice crystals due to varying electric fields. These techniques can now be used in coordination with measurements of electrical fields and radio frequency emissions from lightning discharges to gain valuable new knowledge of the structure and evolution of electric fields in clouds. This report suggests several approaches to the continued investigations of electrical fields in clouds by radars. Atmospheric electricity. (EDC).
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 268
Get Book Here
Book Description
Author: D. R. MacGorman
Publisher: Oxford University Press, USA
ISBN: 9780195073379
Category : Language Arts & Disciplines
Languages : en
Pages : 436
Get Book Here
Book Description
Rapid progress during the last twenty years has created a host of new technologies for studying electrical storms, including lightning mapping systems, new radars, satellite sensors, and new ways of measuring electric field and particle charge. This book explains how these advances have revolutionized our understanding. The books provides substantial background material, making it accessible to a broad scientific audience.
Author:
Publisher:
ISBN:
Category : Geophysics
Languages : en
Pages : 40
Get Book Here
Book Description
Author: V. N. Bringi
Publisher: Cambridge University Press
ISBN: 1139429469
Category : Science
Languages : en
Pages : 664
Get Book Here
Book Description
This 2001 book provides a detailed introduction to the principles of Doppler and polarimetric radar, focusing in particular on their use in the analysis of weather systems. The design features and operation of practical radar systems are highlighted throughout the book in order to illustrate important theoretical foundations.
Author: James I. Metcalf
Publisher:
ISBN:
Category : Doppler radar
Languages : en
Pages : 44
Get Book Here
Book Description
