Solar Quiet Daily (Sq) Geomagnetic Variation During Minimum of Solar Cycles 23/24 A. A. Soloviev 1,2 , A. G. Smirnov 1,3 1 Geophysical Center of RAS, Moscow, Russia; 2 Schmidt Insitute of Physics of the Earth RAS, Moscow, Russia; 3 Helmholtz 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 the E-region of the dayside ionosphere. • We investigate the time-dependent parameters of Sq variation for the historical minimum of solar activity in 2008, based on data from 75 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 Z components. The resulting amplitudes are in line with CMIT simulations. • We analyze equivalent Sq current system using observatory data from narrow European-African latitudinal segment. • Sq current system also strongly depends on solar activity, as current vortices are strongest in the local summer-hemisphere and disinte- grate during local winter. Comparison with CMIT Simulations Ground 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 observatory data (left), and those from Coupled Magnetosphere Ionosphere Thermosphere (CMIT) model (right) for E-season in 2008. Geomagnetic Observatories 60°S 3 0°S 0° 30°N 60°N 120°W 60°W 0° 60°E 120°E A02 AAA ASB BSV CAN CBI CEB CER DRW ESC G01 HLN ILR KTB KUJ LCL LEM LET M01 M03 M04 M09 MLB MSR ONW PPI PTK PUT RIK SHE T16 T17 T24 TIR VRE AAE ABG AIA AMS API AQU ASC ASP BDV BEL BFE BFO BGY BMT BNG BOU BOX BSL CDP CLF CNB CTA CZT DOU EBR ESA ESK EYR FRD FRN FUR GCK GNA GUA GUI GZH HAD HER HLP HON HRB HUA IRT ISK IZN KAK KDU KNY KNZ KOU LRM LVV LZH MAB MBO MIZ MMB NCK NEW NGK NVS OTT PAF PAG PET PHU PPT PST SFS SJG SPT STJ SUA TAM TEO THY TRW TSU TUC UPS VAL VIC VSS WNG A02 AQU BDV BEL BFE BFO BOX CLF DOU EBR ESK FUR GCK HAD HLP HRB ISK IZN LVV MAB NCK NGK PAG SFS SPT SUA THY UPS VAL WNG INTERMAGNET SuperMAG Fig. 1. INTERMAGNET observatories and SuperMag stations used in this study. Sq Variations at Different Latitudes Fig. 2. Sq diurnal variations for J-season 2008 observed at European and African observatories in the LT frame. QD latitudes are shown on the right. Equivalent Sq Current System Modelling Fig. 4. Equivalent Sq current system for 4 seasons in 2008 in the Northern hemisphere, and monthly averaged position of Sq focus altitude. References A. Soloviev, A. Smirnov, A. Gvishiani, J. Karapetyan, A. Simonyan, Quantiﬁcation of Sq parameters in 2008 based on geomagnetic observatory data, Adv. in Space Research, Vo. 64, Issue 11, 2019, DOI: 10.1016/j.asr.2019.08.038.

Solar Quiet Daily (Sq) Geomagnetic Variation During …...Solar Quiet Daily (Sq) Geomagnetic Variation During Minimum of Solar Cycles 23/24 A. A. Soloviev1,2, A. G. Smirnov1,3 1Geophysical

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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.