Magnetometers by IRF observatory - PowerPoint Presentation

Slide1

Magnetometers by IRF observatory

Kiruna

(KIR)

Lycksele

: SGU

in collaboration with IRF (since 2007)

Staff:

M. Yamauchi,

Daria Mikhaylova (technical contact), Mats Luspa (software/database contact),Lars-Göran Vanhainen (technical subcontact), , Csilla Szasz, Peter Volger,Peje Nilsson, Fredrik RutqvistUrban Braendström (Observatory PI) Peter Wintoft (for TOR variometer)

only

variometer

(TOR)

(1) Vector field (every 1 sec):

Flux gate

variometer

(Kiruna)

# Primary ⇐ new one is standby

# Secondary (backup)

(3) Total field (every 4 sec): Proton magnetometer = scalar value (Kiruna) # in operation (old one) # spare (new one)Specialty of Kiruna: near the iron mining

can combine with other measurements - auroral image - riometer - ionosonde (new dynasode from 2017!)(2) Absolute measurement (weekly): DI flux magnetometer (Kiruna) # in operation # spareKiruna magnetometers

(

4) Higher frequency than 1 Hz: Pulsation

magnetometer (

Kiruna

)

#

3 sensors (XYZ) in

oparation

# no spae

Declination

5°

 0°

in

20

years

Some of data products

northward (BX)

eastward (By)vertical downward (BZ

)

11100 nT

10600 nT

0 nT

-1400 nT

52000 nT

50600 nT

average

(baseline +

variometer

)

(1) Unique nowcast ability: combining with auroral image

all-sky image  take meridian part  make keogram  combine

(concept: aurora = optical energy + electric current energy)

Web-interface

aurora ?

auroral keogram

northward component (B

X)

BY and BZ are also shown in the same graphwww2.irf.se/mag/

(2) Unique nowcast of dB/dt and sd(B) over 10 min (+/- 5 min) window.

all-sky image  calculate aurora luminosity at all pixel  strength index

Web-interface (New !)

2018-3-14

breakup 21:30 UT

∆B

X (10-min window)also shows big jump

Add Pulsation magnetometer (future)

Ionospheric ion response to the September 2017 space weather event

M. Yamauchi

1

, T. Sergienko

1

, C.-F. Enell2,

and M. G. Johnsen31. Swedish Institute of Space Physics (IRF), Kiruna, Sweden2. EISCAT Scientific Association Headquarter, Kiruna, Sweden3. Tromsø Geophysical Observatory (TGO), Tromsø, Norway

Advantage of

Scandinavia during the September 2017 event

EISCAT/Norwegian magnetic chain of IMAGE

near local noon when X9.3 flare occurred

near local midnight when ICME arrived, first with IMF

Bz

northward without substorm, and next day with IMF southward with substormnear local noon when only IMF changed from northward to < -15 nTmany sudden southward turnings of IMF in the morning sector where the outflow flux is highcf. Cluster: over cusp (only equinoxes)exactly at cusp when ICME arrived (multiple crossing the cusp) Yamauchi et al. (2018): http://doi.org/10.1029/2018SW001937 Schillings et al. (2018): http://doi.org/10.1186/s40623-019-1048-0

X flares

Bz change

Bz changes

1

st

SEP

/CME

2

nd

SEP

/CME

X flares

1

st

SEP

/CME

Bz change

Bz changes

2

nd

SEP

/CME

day 2017

arrival UTevent

IMF Bz

6 Sep.

~09:00X2.2 flare

< 0 nT

6 Sep.~11:55X9.3 flare < 0 nT 6 Sep.~18 UTX-ray < M-class

~0 nT (B ~ 3 nT) 6 Sep.~20 UT~22 UTSEP-like enhancementIts sharp increase 0 nT (B ~ 3 nT) 6 Sep.

~23:50ICME> 5 nT (change from near zero) 7 Sep.~02:25 – 10:45many Bz changes to < - 5 nT and < 0< -5 nT 7 Sep.~14:30(X1.3 flare)

positive

7 Sep.~20:45

Bz

change to < 0

< -8 nT

7 Sep.

~23:10

ICME

< -25 nT (enhanced from -9 nT)

8 Sep.

~02:

35 – 07:10

many sharp

Bz

polarity

changs

8 Sep.

~11:20

Bz

change to < 0< -5 nT (later -17 nT)

Event list #1

X flares

Bz change

Bz changes

No major substorm by X-flare or 1

st

CME arrival

strong substorm before 2

nd

CME arrival (match with SEP/proton event)

1

st

SEP

/CME

2

nd

SEP

/CME

EISCAT geometry

Density (Ne) spike @<200 km, at the time of X flare

Temperature increase after X flare (pre-condition for outflow)

Sq

current drastically increase after X flare (enough Joule heating)

Auroral-like activity

before CME without ∆BH (IMF was weak, Bz>0)

 only SEP-like event can trigger such activityCME triggered strong Sunward convection at midnight to morning

X 2.2 flares

CME arrivalSEP-like evet

X 9.3 flares

Scandinavia was at right location

X9.3 flare at near local noon (increase ionization rate)EISCAT observed (a) density spike of < 10 min @<200 km (b) increase of Te

(c) No change in upflow after X flare (flare set up only pre-condition?)IMAGE chain detected

Sq current enhancement with ~30 min period (but EISCAT detected Ne enhancement ~ 15 min period) ICME/SEP-like event arrivals at midnight in consecutive days

(Cannot distinguish if the ionospheric effect is due to CME or SEP event)"substorm-like arc motion " without ∆B before ICME but after SEP event

IMF direction is important for substorm (1st: Bz>0, 2nd:

Bz<0)Dayside outflow was 8th>7th>6th increasing by 1-order of magnitude / Cluster observed increase of already-high O+ outflow flux after CME Ionospheric flow after IMF turning southHorizontal flow is enhanced, but upflow is decreased in the morning /Different timing between horizontal flow and vertical flowOutflow region becomes outside EISCAT field-of-view for Bz<0

X flares

1

st

CME

2

nd

CME

Bz change

Bz change

X flares

1

st

CME

2

nd

CME

Bz

change

Bz

changes

Summary

and Discussion

Effect of X-flares

Pre-condition for outflow rather than direct increase of outflow

Sq enhancement with oscillating nature

Effect of ICME (substorm, GOES proton event) or SEP-like event?

Substorm-like motion of auroral arc before ICME  SEP is the cause?Outflow increases, but the cause cannot be distinguished between ICME and SEP-like eventSudden turning to IMF Bz<0It is not clear if southward IMF triggers more outflow in morningIn statistics, outflow flux for Bz<0 is only twice for Bz>0, while outflow flux depend on Kp exponentially

Outflow region becomes outside EISCAT field-if-view for southward IMF Bz>0 might favor outflow if only dayside effect is considered.