2026-09-19T13:29:35Zhttps://dspace.mit.edu/server/oai/requestoai:dspace.mit.edu:1721.1/328972022-01-13T07:54:41Zcom_1721.1_7582com_1721.1_7581col_1721.1_131024
Min-Chang Lee and Richard Temkin.
Dorfman, Seth E
Massachusetts Institute of Technology. Dept. of Physics.
Massachusetts Institute of Technology. Department of Physics
2006-05-15T20:37:45Z
2006-05-15T20:37:45Z
2005
2005
http://hdl.handle.net/1721.1/32897
62621611
Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Physics, 2005.
Includes bibliographical references (leaf 41).
On December 25, 2004, a large-scale ionospheric plasma bubble was observed over Arecibo Observatory in Puerto Rico, inducing significant range spreading on ionograms. This phenomena may be explained by means of the E x B instability and gravitational Rayleigh-Taylor instability. A derivation of the dispersion relations for X and O mode waves transmitted from an ionosonde and an analysis of the collisional Rayleigh-Taylor instability leading to an expression for the growth rate are presented as background information. Ray tracing code developed by Nathan Dalrymple, a previous graduate student of Professor Min-Chang Lee, is extended, first to draw refractive index surfaces to illustrate a key principle in ray tracing and later to simulate range spreading due to depleted ionospheric ducts [1]. Data from Arecibo incoherent scatter radar and Arecibo's CADI digisonde is examined showing strong evidence for the development of a plasma bubble following a rise in the plasma layer and the appearance of a horizontal density gradient. In one portion of the ionosphere, this gradient is found to be at an angle of approximately 70 degrees to the Earth's magnetic field, a favorable condition for the excitation of the Rayleigh-Taylor instability over Arecibo.
by Seth E. Dorfman.
S.B.
59 leaves
2292344 bytes
2293745 bytes
application/pdf
application/pdf
eng
Massachusetts Institute of Technology
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http://dspace.mit.edu/handle/1721.1/7582
Physics.
Intense spreading of radar echoes from ionospheric plasmas
Thesis
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