ionosphere researches based on global navigation satellite...

Ionosphere researches based on Global

Navigation Satellite System data

Yury Yasyukevich on behalf of GNSS monitoring workgroup

Institute of Solar-Terrestrial Physics, Siberian Branch of Russian Academy of Sciences

[email protected]

Worldwide GPS/GLONASS receiver distribution

Irkutsk. We are here!

Prof. E.L. Afraimovich, founder of the Group

Mar. 12, 1941 – Nov. 08, 2009

F layer (250-300 km)

E layer (100 km)

D layer (60-70 km)

h

Ne – the number of

electrons per unit volume

TEC – total electron content

Ne

D

drrNeI0

)(

Ionospheric pierce point

– “slant” TEC

Ionosphere

21 61 01 mT E C U

GNSS-sounding

GPS PRN01

GLONASS 01

PRN31

f1=1575.42 MHz

f2=1227.60 MHz

h=20 200 km

Ionosphere

maximum

Ionosphere pierce point

GPS PRN02

f1=1602.0+k 0.5625 MHz

f2=1246.60+k 0.4375 MHz

h=19 100 km

GPS-30

satellites

GLONASS

24 satellites

Counting the total electron content (TEC)

Variations of total electron content are determined by phase (1) and code (2) measurements

constLLff

ffI 22112

22

1

22

21

308.40

1

cDCBPPff

ffI 122

22

1

22

21

308.40

1

The code measurement noises are much stronger, but they do not have a constant related to the

measurement ambiguity. However Eq. (2) contains the constant related to the misalignment of

the frequency channels.

(1)

(2)

Ionosphere response to solar flare

Response to solar flares

М4.6 С2.5

[Afraimovich E.L. et al. The response of the ionosphere to faint and bright solar flares as deduced

from global GPS network data. Annals of Geophysics, 2002, V.45, N.1, 31-40. ]

Bright flare

Jul. 14, 1998

Faint flare

Jul. 29, 1998

Ionospheric response to faint flares

We can single out responses to contiguous

faint solar flares using

coherent integration. Meanwhile, response to

flares in single LOS did not reveal itself.

3.2 3.6 4 4.4

UT, hours

-0.4

0

0.4

0.8

<d

I/d

t>, 10

-3 T

EC

U

0x100

2x10-6

4x10-6

6x10-6

8x10-6

X-ray, W/m2

08 Feb., 2010

3.2 3.6 4 4.4

UT, hours

0

2

4

6

8

10

I, T

EC

U

PAPE - PRN07

AUCK - PRN08

С6.2C2.4

C7.7

[Yu. V. Yasyukevich et al. Ionospheric Response to Solar Flares of C and M Classes in January–

February 2010 // Cosmic Research, 2013, Vol. 51, No. 2, pp. 114–123]

Ionospheric response to the 2017 September 06 strong flares

Spatial structure of the 2010 Feb. 7 М6.4 solar

flare response

We can see the simultaneous growth of the total content derivative at

the maximum flare instant. Then, the slump begins,

and the coincidence of the derivative with respect to

space is broken.

The TEC value derivative is up to ~ 1.5.

[Yu. V. Yasyukevich et al. Ionospheric Response to Solar Flares of C and M Classes in January–

February 2010 // Cosmic Research, 2013, Vol. 51, No. 2, pp. 114–123]

Slips during solar flares

Solar radio flux during solar flares can

significantly impact on the navigation system

operation. During the 2006 December solar

flares, it was found that up to 80% stations might not have received navigation

signals for different receivers

[Afraimovich et al. Malfunction of Satellite Navigation Systems GPS and GLONASS Caused by Powerful Radio Emission of the

Sun During Flares on December 6 and 13, 2006, and October 28, 2003 // Cosmic Research, 2009,V.47, N2, 126-137]

Slips during the 2006 December

solar flares: GPS vs GLONASS

Slip frequency of radio navigation parameter

determination increases during solar flares. One can see that the slip frequency

for GPS is manyfold higher for both flares.

[Afraimovich et al. Malfunction of Satellite Navigation Systems GPS and GLONASS Caused by Powerful Radio Emission of the

Sun During Flares on December 6 and 13, 2006, and October 28, 2003 // Cosmic Research, 2009,V.47, N2, 126-137]

Solar-terminator-caused ionospheric irregularities

ST-generated wave medium-scale disturbances

[Afraimovich et al. Spatio-temporal structure of the wave packets generated by the solar

terminator // Advances in Space Research, 2009, doi:10.1016/j.asr.2009.05.017.]

Dynamics of TEC variations

[Afraimovich et al. Spatio-temporal structure of the wave packets generated by the solar

terminator // Advances in Space Research, 2009, doi:10.1016/j.asr.2009.05.017.]

The magnetohydrodynamic nature of

wave packets

Four factors indicate the MHD nature of the observed ST effects: retaining

intensity fluctuations, retaining the wavefront orientation, its coinciding

with the MS ST line slope, and latitudinal variations of WP record start

time.

[Edemskiy and Yasyukevich. Duration of wave disturbances generated by solar terminator in

magneto-conjugate areas // Proceedings of XXX URSI General Assembly. 2011. GP2-11.]

Ionosphere response to earthquakes

Generation scheme of ionospheric disturbances during an earthquake

TEC behavior during an

earthquake

Ionosphere response to earthquakes

Japan

GPS receivers Earthquake epicentrum

Japan earthquake September 25, 2003

[Afraimovich et al. Determination of the Characteristics of Ionospheric Perturbations in the Near-Field Region of an

Earthquake Epicenter of September, 25, 2003 Hokkaido earthquake // Radiophysics and Quantum Electronics, 2005,

V.48, N4, 268-280]

The 2011 March 11 Tohoku earthquake in Japan (Mw=9)

There were TEC disturbances,

that had a circular shape with

the center near the

earthquake epicenter.

It was possible to identify

two main types of a circular

disturbance:

medium-scale (wavelength ~

200 km, see slide)

and large-scale (wavelength

~ 600 km).

Space launching

[Afraimovich E.L. et al. The use of GPS-arrays in detecting shock-acoustic waves generated during

rocket launchings // J.Atm. Solar-Terr. Phys., 2001, V.63, N18, 1941-1957. ]

Large-scale field aligned irregularities

Large-scale field aligned irregularities (FAI)

Inhomogeneity of with a positive deviation from the background (the

amplitude of ~ 4 TECU) was moving north at about 150 m / s.

[Afraimovich et al. The mid-latitude field-aligned disturbances and its impact on differential GPS

and VLBI. Advances in Space Research, 2011, V. 47, P. 1804–1813. DOI:10.1016/j.asr.2010.06.030.]

Large-scale FAI

[Afraimovich et al. Isolated ionospheric disturbances as deduced from global GPS network

//Annales Geophysicae (2004) 22: 47–62

0 500 1000

0

100

200

300

400

B

Время

10

15

20

25

30

I(t)

, T

EC

U

0 500 1000

0

100

200

300

400

B

Время

10

15

20

25

30

I(t)

, T

EC

U

0 500 1000

0

100

200

300

400

B

Время

10

15

20

25

30

I(t)

, T

EC

U

0 500 1000

0

100

200

300

400

B

Время

10

15

20

25

30

I(t)

, T

EC

U

0 500 1000

0

100

200

300

400

B

Время

10

15

20

25

30

I(t)

, T

EC

U

Ionospheric blobs

0 500 1000

0

100

200

300

400

B

Время

10

15

20

25

30

I(t)

, T

EC

U

[Afraimovich et al. The mid-latitude field-aligned disturbances and its impact on differential GPS

and VLBI. Advances in Space Research, 2011, V. 47, P. 1804–1813. DOI:10.1016/j.asr.2010.06.030.]

N(t) is number of

receivers at which slips

of auxiliary frequency

phase L2 tracking were

observed.

The slip density

reached 20% for

different satellites .

Ionospheric bubbles

[Afraimovich E.L. et al. The response of the ionosphere to faint and bright solar flares as deduced

from global GPS network data. Annals of Geophysics, 2002, V.45, N.1, 31-40. ]

TEC variation spatial

distribution, as well as

the distribution of

phase slips from the

data of а satellite with

a slip minimum.

Ionospheric bubbles

[Demyanov et al. Effects of ionosphere super-bubble on the GPS positioning performance depending on the orientation

relative to geomagnetic field // GPS solutions, V. 16, N 2, P.181-189. 2012. DOI: 10.1007/s10291-011-0217-9.]

Ionospheric bubbles

Bold line mark path sections between 11:00 and 14:00 UT, where there was the largest

number of slips.



Ionospheric bubbles

P(γ) is a relative number of slips observed at each satellite. There were 4 satellites 11 through 14 UT. The bulk of slips was observed at the magnetic field angles of the Earth near 0 and 90 degrees.



Solar eclipses

2009 July 22 TEC variations are

recorded, at least, at the

eclipse minimum phase.

The main parameters

characterizing the eclipse

are the minimum time and

the TEC amplitude

variations. These

parameters vary

significantly eclipse-to-

eclipse.

Solar eclipses

[Afraimovich et al. Ionspheric effects of the 2009 July 22 total solar eclipse on the dense GPS

network GEONET, 2010 (in Russian).

Solar eclipses

[Afraimovich et al. Ionspheric effects of the 2009 July 22 total solar eclipse on the dense GPS

network GEONET, 2010 (in Russian).

The 2017 August 21 total solar eclipse

A comparison of the TEC noise spatial distribution with the maps of the meridional (V) and zonal (U) wind speed within the TC KATRINA showed that the area where the increased TEC disturbances were recorded coincided with the areas of increased (in absolute value) values of the meridional wind speed (Fig. 6).

The trajectories of the "GPS receiver-satellite" LOS above the TC KATRINA region. Squares show the GPS-station positions, color filling is the distribution of the meridional (V) wind speed at 06:00 UT, 2005 Aug 28. The numbers indicate PRN of satellite GPS (PRN02, PRN04, PRN10).

28.08.2005

06:00 UT

Same but filling shows the distribution of the zonal (U) wind speed at 06:00 UT, 2005 Aug 28.

28.08.2005

06:00 UT

TEC variations during Cyclone "Katrina"

[Polyakova and Perevalova. Investigation into impact of tropical cyclones on the ionosphere using

GPS sounding and NCEP/NCAR Reanalysis data // Adv Space Res 48(7):15 (2011)]

Magnetic storms

The 2015 June 22 magnetic storm

•At 18:39 UT we recorded that Bz IMF component turned to south along with sharp increase in Flux pressure. •Also we recorded strong electric field which can penetrate in the ionosphere and results in enhancement of fountain effect. •At ~18:35 we recorded sudden storm commencement with positive H-SYM up to +88 nT, sharp increase in proton density as well as sharp increase in solar wind flow speed. I

II

Bz

Flux

speed

Proton

density

Flux

Pressure

E

SYM/H

TEC variations durign the 2015 June 22

magnetic storm

Ionospheric storm results in strong large-scale irregularities which originated at auroral oval boundaries and reached even opposite hemisphere.

Total electron content slips

Precise TEC measurement is important for space weather and for naviagion tasks. If the measurement is unphysical we said that it is TEC slip. Great correlation between increase in probability of TEC measurements slips and storm development. At 18:35 TEC slips increased just when SSC occurred. Overal increasing during the storm is 5-8 times.

Global distribution of GPS loss-of-phaselock

The spatial distribution of slips before

the 2003 November 20 superstorm

The bulk of slips occurs in the auroral

region.

During the magnetic storm

main phase, the area of

maximum slips can extend to

midlatitudes.

[Astafyeva et al. First global maps of GPS phase slips and of GPS positioning errors. Abstracts of 39th

COSPAR Scientific Assembly 2012. C1.1-0037-12]

Global electron content

GEC = total number of electrons in the near-Earth space

GEC 0,5-4·1032 electrons

Solar activity index

Geomagnetic activity index :

The index of the near-Earth space :

W, F10.7 и etc.

Dst, Kp, Ap и etc.

GEC

GEC - global electron content

[Afraimovich et al. Ann. Geophys., 2008]

GEC- global electron content

GEC features significant annual, semi-annual and 27-day variations.

GEC- global electron content

GEC and Irkutsk annual variations are opposite in phase, semiannual are

in phase. Amplitude of semiannual variation during solar maxima an

order exceed those in minima.

Dynamics of Global electron content

during the 2015 June 22 magnetic storm

Due to increased ionization in the equatorial region as well as

possible ionospheric storm in the dayside sector we obtain increase

in global ionization.

Later the storm is of negative character. So we have had 20% increase and then sharp ~50%

decrease in GEC.

Thank you for your attention!

ionosphere researches based on global navigation satellite...

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