| TI: |
Title
Electromagnetic fields generated by a three dimensional global
ocean circulation |
| AU: |
Author
Tyler, RH; Mysak, LA; Oberhuber, JM |
| AF: |
Author Affiliation
Applied Phys. Lab., Univ. Washington, Seattle, WA, USA |
| SO: |
Source
J. GEOPHYS. RES. (C OCEANS), vol. 102, no. 3, pp. 5531-5551, 1997
|
| IS: |
ISSN
0148-0227 |
| AB: |
Abstract
A simplified form of the motional induction equation is used to
calculate the dominant three-dimensional (3-D) electromagnetic
(EM) fields generated by a specified steady 3-D global ocean circulation.
The EM calculations require, at most, vertical integrations and
do not require running a global 3-D model. Two cases for ocean
bottom conductivity are considered: an electrically insulating
ocean bottom and a high-conductance sediment layer. The approximations
are discussed, and the solutions are plotted for various depth
levels. Many aspects of the dominant ocean-generated EM fields
(particularly the electric currents near the sea surface and the
magnetic fields) are shown to be insensitive to ocean bottom conductivity.
Other aspects (particularly the horizontal electric field in shallow
water) are very sensitive. We perform a global integration to
estimate the role of the "nonlocal" electric currents. We find
that the importance in including these nonlocal currents when
making EM field estimates is the same or less than that for including
a model for the bottom conductance. Hence the simple EM estimates
from one- dimensional integrations are not improved in globally
integrated models until these models include a realistic model
for bottom conductivity. |
| LA: |
Language
English |
| SL: |
Summary Language
English |
| PY: |
Publication Year
1997 |
| PT: |
Publication Type
Journal Article |
| DE: |
Descriptors
electromagnetism; ocean circulation; World Ocean; models |
| ER: |
Environmental Regime
Marine |
| TR: |
ASFA Input Center Number
CS9714161 |
| CL: |
Classification
Q2 02164 Ocean circulation and currents; O 2090 Instruments/Methods
|
| EM: |
Entry Month
9707 |
| SF: |
Subfile
ASFA 2: Ocean Technology Policy & Non-Living Resources; Oceanic
Abstracts |
| AN: |
Accession Number
4071454 |
