-

.., .., .., .. (),

. (NOAA, Boulder), . (IWF, Graz)

Birkeland (1908), Bostrom (1964), Atkinson (1967), McPherron (1972 ) ground-ATS-1, Caan et (1973) lobe-ground McPherron et al. (1973) Substorm Current Wedge

-- n*106 -

Horning et al., 1974 SCW ; . , 2008 . Craymosan et al.,1995 Sergeev et al., 1996 74, IGRF SCW !! ( I, . ) (87- .,1986), Tsyganenko (1997) SCW . - (? , ) SCW ; SCW

, , (FW) ( 6.6Re) . ;

Mthod: Economical Biot-Savart summation, with a possibility to flexibly deform electric current distributions within wide limits. 2. Calculate A by integrating along flow lines of J and remove singularity by assuming a variable transverse thickness of the electric current flow tube: From the very beginning, work with a vector potential, in order to keep divB=0 when spreading out the currents over a finite volume in space:so that at |r-r|>>D the field remains currrent- free, while at |r-r|

3. Common problem of the Biot-Savart approach: the summation requires a very fine grid of current elements, which often results in prohibitevely slow algorithms. We overcome that difficulty by replacing many point elements by much fewer number of rectilinear segments:replacing the integralwhreby the sum: (FW) 2

Flow lines of spread-out model electric current, based on a loop with 245 segments and D=0.1R3/2. Volume current density is calculated as j ~ rot B, B = rot A, with derived by summation over individual segments.The model allows any arbitrary deformation of both the circuit geometry and the variable loop thickness D=D(s), without violating div B=0 and without any undesired artificial currents outside of the loop. NB: By contrast to the above method, deforming the magnetic field [Stern, 1987; Tsyganenko, 1998] conserves only div B=0, but not rot B ! (FW) 3

( FW ) - 4

IGRF + T89, - ,

:

Pw, Pe ; Iscw . RT - ; RCF 89; D :~ B-1/2 ,

SCW ( FW) YZ XZ Bz X GSM

INTERMAGNET

, Cluster (XY) \ Sergeev et al., JGR, 1996

3-. SCW + DRP + DR

(20-50 ) INTERMAGNET

Iscw, Pe, Pw,

, , (FW) ( 6.6Re) . (Iscw, RT - , Pe, Pw ) ( Iscw, Pe, Pw )

02.10.2006 ( 05:08, 06:17 07:14)

- Cluster-1, Cluster-2, Geotail RT, Iscw iobs-imod2 14-18RE (12 ), ; RT =15RE Bobs/Bmod SCW 1,5-2 , , PS

- Bx Bz (I ..) ( 14 , t=3min ) :

(~0.7) ;

Bobs/Bmod >1

25 2006-2010 ., GOES-10,-11,-12, t=3min

RWA . . SCW; , RT=15Re

: - ~ 25-30 1 , . C D RWA ;

:

, SCW, . - 6.6 Re

, , (FW) ( 6.6Re) .

SCW 6.6Re Hobs/Hmod :

Hobs/Hmod 1 ( 10 );

Hobs/Hmod 2.5 ( 10 );

Hobs/Hmod (6.6Re) Hobs/Hmod :

(1) (RCF);(2) ;

FW SCW ( R1) .

Hobs/Hmod SCW

( R2)

Hobs/Hmod 6.6 Re Hobs/Hmod 1

Hobs/Hmod .Baumjohann et al., JGR 1999: . . Hobs/Hmod

R2 ? (BBF) - R2

. Birn et al., JGR 1999:

E N D ?V. A. Sergeev, N. A. Tsyganenko, M.V. Smirnov, A.V. Nikolaev, H.J. Singer, W. Baumjohann, Magnetic effects of the substorm current wedge in a 'spread-out wire' model and their comparison with ground, geosynchronous, and tail lobe data, JGR, submitted, 2011.

( FW ) - 4 :Pw, Pe ;Iscw .RCF .

D (~ R3/2 ) .

SCW = IGRF + T89

(Bx, By, Bz ):

T89 model field lines for FAC routeRegulate stretching by 1 parameter (RC) Main parameters : I, Pw,Pe, R RT to be determined later (~ 15Re)

Some further details

SCW (T09SCW) Bx Z GSM (X = -15RE , Y = 0)

2006.09.27 09:28 10:00, 2 : - GSM ( ); - ; - .

TW09 . Sergeev et al., JGR, 1996

3-. SCW + DRP + DR

(20-50 ) INTERMAGNET

Iscw, Pe, Pw,

, : 14-18RE ( Cluster Geotail), ; , 1.5-3.0 ; (TW09) , 8-18RE, TW09 ; Bx Bz ~1.5 , , .

*****