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]
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
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
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.
[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
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.
[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.]
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!