Solar Quiet Daily (Sq) Geomagnetic Variation During …...Solar Quiet Daily (Sq) Geomagnetic...
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Solar Quiet Daily (Sq)Geomagnetic Variation DuringMinimum of Solar Cycles 23/24A. A. Soloviev1,2, A. G. Smirnov1,3
1Geophysical Center of RAS, Moscow, Russia; 2Schmidt Insitute of Physics of the Earth RAS, Moscow, Russia; 3Helmholtz Centre Potsdam GFZ -German Research Centre for Geosciences, Potsdam, Germany.
Email: [email protected]
Abstract• The most regular of all geomagnetic variations is the solar quiet
daily (Sq) variation, attributed to the two vortices flowing in theE-region of the dayside ionosphere.
• We investigate the time-dependent parameters of Sq variation forthe historical minimum of solar activity in 2008, based on data from75 INTERMAGNET observatories and 46 SuperMag stations.
• Quiet days were selected using the ’Measure of Anomalousness’(MA) algorithm, based on fuzzy logic.
• We present global maps of seasonal Sq amplitudes of X,Y and Zcomponents. The resulting amplitudes are in line with CMIT simu-lations.
• We analyze equivalent Sq current system using observatory datafrom narrow European-African latitudinal segment.
• Sq current system also strongly depends on solar activity, as currentvortices are strongest in the local summer-hemisphere and disinte-grate during local winter.
Comparison with CMIT SimulationsGround data : Sq(X) amplitude, E-season 2008 CMIT : Sq(X) amplitude, E-season 2008
Ground data : Sq(Y) amplitude, E-season 2008 CMIT : Sq(Y) amplitude, E-season 2008
Ground data : Sq(Z) amplitude, E-season 2008 CMIT : Sq(Z) amplitude, E-season 2008
[Soloviev, Smirnov et al., 2019] [Cnossen and Richmond, 2013]
Fig. 3. Sq amplitudes of X,Y and Z components obtained from ground ob-servatory data (left), and those from Coupled Magnetosphere IonosphereThermosphere (CMIT) model (right) for E-season in 2008.
Geomagnetic Observatories
60°S
30°S
0°
30°N
60°N
120°W 60°W 0° 60°E 120°E
A02
AAAASB
BSV
CAN
CBI
CEB
CER
DRW
ESC
G01
HLN
ILR
KTB
KUJ
LCL
LEM
LETM01M03M04
M09
MLB
MSR
ONW
PPI
PTK
PUT
RIK
SHE
T16T17T24
TIR
VRE
AAE
ABG
AIA
AMS
API
AQU
ASC
ASP
BDVBEL
BFE
BFO
BGY
BMT
BNG
BOU
BOX
BSLCDP
CLF
CNB
CTA
CZT
DOU
EBRESA
ESK
EYR
FRDFRN
FURGCK
GNA
GUA
GUIGZH
HAD
HER
HLP
HON
HRB
HUA
IRT
ISKIZNKAK
KDU
KNY
KNZ
KOU
LRM
LVV
LZH
MAB
MBO
MIZ
MMBNCK
NEW
NGKNVS
OTT
PAF
PAGPET
PHU
PPT
PST
SFS
SJG
SPT
STJSUA
TAMTEO
THY
TRW
TSU
TUC
UPS
VAL
VIC
VSS
WNG
60°N
A02
AQU
BDV BEL
BFE
BFO
BOX
CLFDOU
EBR
ESK
FUR
GCK
HAD
HLP
HRB
ISKIZN
LVVMAB
NCK
NGK
PAG
SFS
SPT
SUATHY
UPS
VALWNG
INTERMAGNET + SuperMag
INTERMAGNETSuperMAG
Fig. 1. INTERMAGNET observatories and SuperMag stations used inthis study.
Sq Variations at Different Latitudes
Fig. 2. Sq diurnal variations for J-season 2008 observed at European andAfrican observatories in the LT frame. QD latitudes are shown on theright.
Equivalent Sq Current System Modelling
Fig. 4. Equivalent Sq current system for 4 seasons in 2008 in the Northernhemisphere, and monthly averaged position of Sq focus altitude.
ReferencesA. Soloviev, A. Smirnov, A. Gvishiani, J. Karapetyan, A. Simonyan,Quantification of Sq parameters in 2008 based on geomagnetic obser-vatory data, Adv. in Space Research, Vo. 64, Issue 11, 2019, DOI:10.1016/j.asr.2019.08.038.