Premium
Further investigation of the interference minimums in the low‐frequency electromagnetic fields produced by a submerged vertical magnetic dipole
Author(s) -
Inan A. S.,
FraserSmith A. C.
Publication year - 1990
Publication title -
radio science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.371
H-Index - 84
eISSN - 1944-799X
pISSN - 0048-6604
DOI - 10.1029/rs025i004p00339
Subject(s) - amplitude , dipole , magnetic dipole , magnetic field , physics , electromagnetic field , range (aeronautics) , point source , computational physics , optics , materials science , quantum mechanics , composite material
The quasi‐static electromagnetic fields generated along the sea surface by a submerged vertical magnetic dipole are evaluated numerically using exact expressions and the results are plotted in a parametric form for source depths varying from 2 to 14 seawater skin depths δ. The curves show that there is a minimum in the amplitude of the vertical component of the magnetic field for horizontal distances from the source in the range 9–14δ and for dipole depths ranging from 2 to 8δ, with the deepest minimum occurring at a horizontal distance of p min ≃ 11.07δ when the dipole is at a critical depth of d c ≃ 4.22δ. There also exists a similar minimum point in the variation along the surface of the amplitude of the total electric field for horizontal distances from the source in the range 10–20δ and dipole depths ranging from 4 to 23δ, with the deepest minimum occurring at a horizontal distance of p min ≃ 12.95δ when the dipole is at a depth of d c ≃ 9.38δ. Both minimums are due to the strong destructive interference between the direct and the lateral wave components of the fields. No such minimum point exists for the variation of the amplitude of the horizontal component of the magnetic field.