structure and variability of the main ionospheric trough:...
TRANSCRIPT
Structure and Variability of the Main Ionospheric
Trough: Empirical Modeling, Validation
and Physical Explanation
Maxim Klimenko1, Alexander Karpachev2, Vladimir Klimenko1, Nikolai Chirik1,
Gennadii Zhbankov3, Lubov Pustovalova2, David Themens4
1West Department of Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation
RAS Kaliningrad, Russia, e-mail: [email protected] of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation RAS Moscow, Russia,
e-mail: [email protected] Federal University, Rostov-on-Don, Russia, e-mail: [email protected]
4University of New Brunswick, New Brunswick, Canada, e-mail: [email protected]
UNIWERSYTET WARMINSKO MAZURSKI W OLSZTYNIE
Beacon Satellite Symposium 2019
August 19 – 23, 2019
IRI options for NmF2 (foF2) calculation
CCIR – 1967
Jones и Gallet, 1962
Jones et al., 1969
Ionosonde 1954-1958
Ocean and southern
hemisphere screen points
through extrapolation
along lines of constant
magnetic-dip angle.
IRTAM – 2012
Galkin, Reinisch, Huang и Bilitza,
2012
45 digisonde stations
Non-Linear Error Compensating
Technique for Associative Restoration
(NECTAR) is used to adjust the
CCIR coefficients to much real-time
digisonde measurements by the
Global Ionosphere Radio Observatory
(GIRO) network of digisondes.
URSI – 1988
Fox и McNamara,1988
Rush et al.,1989
45,000 station month of
ionosonde data
Theoretical model was
adjusted such that it agreed
with measured foF2 values
over land.
Seasonal dependence of effectiveness of model
correction procedure based on GNSS TEC data
360º
NeQuickIRI-Plas
Rz12
TECobs TECobs
TECmod
http://irimodel.org/
indices/ig_rz.dat
new Rz12
20º
Ovodenko et al., 2015; Kotova et al., 2017, 2018
corrected model results (foF2, TEC, etc.)
greatest improvement for Spring, worst efficiency for Winter
Main Ionospheric Trough (MIT) as the main structure of the subauroral
ionosphere
40 50 60 70
1E+005
200000
400000
80000
60000
40 50 60 70 80 90
1E+004
1E+005
20000
40000
60000
80000
200000
Ne, cm-3
ILAT, degree
CHAMP10/12/2004, 12.4LT400 km
Intercosmos-1930/09/1980, 4.6LThmF2
Cosmos-90026/07/1979, 0.9LT375 km
40 50 60 70
1E+005
200000
400000
600000
80000
60000
Seasonal variation of MIT
occurrence probabilityP%
Months
Two trough problem signature
in statistical data analysis
Northern hemisphere, HSA
40 50 60 70 80 90Latitude, deg
1
1.5
2
2.5
3January 24, 2006, 52E, 7.9LT, Kp=3-
72.9o
73.6o
62.1o
February 02, 2006, 75E, 8LT, Kp=3
fp, MHz
50
60
70
80
60
70
80
0 90 180 270 360Longitude, deg
60
70
80
07 LT 10 LT
12 LT
0 90 180 270 360Longitude, deg
50
60
70
80 7-8 LT 8-9 LT
Northern hemisphere, HSAGMLat, deg
=2.1, r=0.68
=3.1, r=0.72=4.1, r=0.62
Our Database for empirical model~5 000 000 COSMIC Ne-profiles (2006-2017)~200 000 GRACE Ne-profiles (2007-2015)~300 000 CHAMP Ne-profiles (2001-2008)http://cdaac-www.cosmic.ucar.edu/cdaac/products.html - data massivehttp://lasp.colorado.edu/lisird/tss/noaa_radio_flux.html - F10.7 values
Data for Main Ionospheric Trough (MIT) model200 000 Ne(h) - Intercosmos-19 profiles, CHAMP in-situ NeIonosonde measurements data
-180 -150 -120 -90 -60 -30 0 30 60 90 120 150 180
Longitude (deg)
Measurements count
-90
-60
-30
0
30
60
90
Lat
itud
e (d
eg)
0
40
80
120
160
200
240
280
320
360
400
June, 12:00 LT December, 24:00 LT
Number of COSMIC, CHAMP, GRACE Data
-180 -150 -120 -90 -60 -30 0 30 60 90 120 150 180
Longitude (deg)
Measurements count
-90
-60
-30
0
30
60
90
Lat
itud
e (d
eg)
0
40
80
120
160
200
240
280
320
360
400
-180 -150 -120 -90 -60 -30 0 30 60 90 120 150 180
Longitude (deg)
Measurements count
-90
-60
-30
0
30
60
90
Lat
itud
e (d
eg)
0
40
80
120
160
200
240
280
320
360
400
Main Ionospheric Trough (MIT) Model
Developed in IZMIRAN
• Empirical MIT model is valid for quiet (Kp = 2) local winter conditions over the Northern and Southern Hemispheres for all local times and levels of solar activity.
• The model describes the trough position and its shape (i.e. foF2 distribution in the trough region).
• Experimental basis of the model: Cosmos-900 (2500 orbits of in situ Ne measurements at ~550 km), Intercosmos-19 (3000 obits topside sounding foF2 observation), CHAMP (15000 orbits of in situ Ne measurements at 350-550 km) satellites data.
MIT model (IZMIRAN)Karpachev et al, 2016
MIT Model Results (Online Service)
http://www.izmiran.ru/ionosphere/sm-mit/
IRI
model
MIT
model
RO
data
-180-150-120 -90 -60 -30 0 30 60 90 120 150 180
Longitude (deg)
foF2 (MHz) 24:00 LT Dec. F10.7 = 80
45
55
65
75
Lat
itud
e (d
eg)
1
1.5
2
2.5
3
3.5
Northern Hemisphere Southern Hemisphere
Comparison for F10.7=120
-180-150-120 -90 -60 -30 0 30 60 90 120 150 180
Longitude (deg)
foF2 (MHz) 24:00 LT Dec. F10.7 = 120
45
55
65
75
Lat
itud
e (d
eg)
1
1.5
2
2.5
3
3.5
4
-180-150-120 -90 -60 -30 0 30 60 90 120 150 180
Longitude (deg)
foF2 (MHz) 24:00 LT Jun. F10.7 = 120
-80
-70
-60
-50
-40
Lat
itud
e (d
eg)
1
1.5
2
2.5
3
3.5
4
-180-150-120 -90 -60 -30 0 30 60 90 120 150 180
Longitude (deg)
foF2 (MHz) 24:00 LT Dec. F10.7 = 120
45
55
65
75
Lat
itud
e (d
eg)
1
1.5
2
2.5
3
3.5
4
-180-150-120 -90 -60 -30 0 30 60 90 120 150 180
Longitude (deg)
foF2 (MHz) 24:00 LT Jun. F10.7 = 120
-80
-70
-60
-50
-40
Lat
itud
e (d
eg)
1
1.5
2
2.5
3
3.5
4
-180-150-120 -90 -60 -30 0 30 60 90 120 150 180
Longitude (deg)
foF2 (MHz) 24:00 LT Dec. F10.7 = 120
45
55
65
75
Lat
itud
e (d
eg)
1
1.5
2
2.5
3
3.5
4
-180-150-120 -90 -60 -30 0 30 60 90 120 150 180
Longitude (deg)
foF2 (MHz) 24:00 LT Jun. F10.7 = 120
-80
-70
-60
-50
-40L
atit
ud
e (d
eg)
1
1.5
2
2.5
3
3.5
4
C) MIT ModelB) IRI
Mechanisms for longitudinal variation of MIT
daytime
nighttime
important for daytime important for nighttime
Conclusion
We do the following steps:
• extended and modified Main Ionospheric Trough (MIT) empirical model
(http://www.izmiran.ru/ionosphere/sm-mit/)
• created Python program code for F2 peak parameters (NmF2, hmF2)
global empirical model development based on radiooccultation data
• explained mechanisms for daytime and nighttime longitudinal structure
of the main ionospheric trough for winter solar MIN condition
5
Work was supported by the Russian Science Foundation grant 17-77-20009
Mechanisms for daytime longitudinal variation of MIT
Mechanisms for nighttime longitudinal variation of MIT