Geoscience Reference
In-Depth Information
ik R V 0 1 q 2
q m
b y D
f a 2 exp .p z / 3 exp .qk R z / g ;
(7.116)
a 3 exp .p z / C
s exp .sk R z / ;
k R V 0
m
i 1
q exp .qk R z / C
i 2
b z D
(7.117)
where a 1 , a 2 , and a 3 are undermined coefficients while the coefficient 1 and 2 are
determined by Eq. ( 7.68 ) and the coefficient 3 is given by
3 D B 0y ! 2
1
i!
m
C l
:
(7.118)
Besides the coefficients q and s are given by Eq. ( 7.61 ) and p D k R i!= m 1=2
is defined in such a way that Rep>0.
In a similar manner one can find the solutions of Eq. ( 7.66 ) for the atmosphere
. z >0/
b j D d j exp . k R z /;j D x;y; z ;
(7.119)
where d j denote the undefined coefficients.
It is easy to show that the solutions ( 7.115 )-( 7.117 ) and ( 7.119 ) satisfy Maxwell
equation r ı B D 0 under the requirements that ik R a 1 D pa 3 and d 3 D id 1 .
All the components of electromagnetic perturbations must be continuous at the
boundary z D 0. In addition, the normal component of the conduction current is
equal to zero at z D 0 because the atmosphere is supposed to be an insulator. It
follows from these boundary conditions that
.1 C q/ 1
;
p
k R C p
q C .1 C s/ 2
a 1 D
(7.120)
s
.qk R p/ 1
;
k R V 0
m
q C .sk R p/ 2
d 1 D
(7.121)
s
a 2 D 3 ;d 2 D 0:
(7.122)
We thus have just found all the coefficients in Eqs. ( 7.115 )-( 7.117 )forthe
amplitudes b x , b y , and b z of magnetic perturbations. Substituting these amplitudes
into Eq. ( 7.62 ) gives the vector ı B .x; z ;t/, that is, the solution of problem. The
electric field E is related to ı B through Eq. ( 7.11 ).
 
Search WWH ::




Custom Search