locations of boundaries of outer and inner radiation belts as observed by
DESCRIPTION
Locations of boundaries of outer and inner radiation belts as observed by Cluster and Double Star. Natalia Ganushkina (1, 2), Iannis Dandouras (3), Yuri Shprits (4) and Jinbin Cao (5) Finnish Meteorological Institute, Helsinki, Finland University of Michigan, Ann Arbor, USA - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Locations of boundaries of outer and inner radiation belts as observed by](https://reader036.vdocuments.site/reader036/viewer/2022062500/5681584e550346895dc5ab43/html5/thumbnails/1.jpg)
Locations of boundaries of outer and inner radiation belts as observed by
Cluster and Double Star
Natalia Ganushkina (1, 2), Iannis Dandouras (3), Yuri Shprits (4)and Jinbin Cao (5)
(1) Finnish Meteorological Institute, Helsinki, Finland(2) University of Michigan, Ann Arbor, USA
(3) CESR, Toulouse, France(4) UCLA, USA
(5) State Key Laboratory of Space Weather, CSSAR, CAS, Beijing, China
2011 Joint CEDAR-GEM Workshop,26 June - 01 July 2011, Santa Fe, NM, USA
![Page 2: Locations of boundaries of outer and inner radiation belts as observed by](https://reader036.vdocuments.site/reader036/viewer/2022062500/5681584e550346895dc5ab43/html5/thumbnails/2.jpg)
CLUSTER CIS measurements between April 2007 and June 2009
The Cluster Ion Spectrometry (CIS) experiment on board Cluster:- provides the three-dimensional ion distributions with one spacecraft spin (4 sec) time resolution [Rème et al., 2001];- consists of two complementary spectrometers HIA and CODIF.
Time-of-flight ion COmposition and DIstribution Function (CODIF) sensor:- high-sensitivity mass-resolving spectrometer to measure complete 3D distribution functions;- for major ion species H+, He++, He+ and O+ within one spin period; - covers the energy range between 0.02 and 40 keV/charge.
Hot Ion Analyser (HIA) sensor:- Ions in the energy range ~ 5 eV/e – 32 keV/e;- does not provide mass discrimination;- but has a better angular resolution (~ 5.6°).
![Page 3: Locations of boundaries of outer and inner radiation belts as observed by](https://reader036.vdocuments.site/reader036/viewer/2022062500/5681584e550346895dc5ab43/html5/thumbnails/3.jpg)
CLUSTER orbit at perigee on June 30, 2008During the period between April 2007 and June 2009 Cluster was deep in the radiation belts coming to Earth at its perigee as close as L = 2.
ORB
IRB
ORB
![Page 4: Locations of boundaries of outer and inner radiation belts as observed by](https://reader036.vdocuments.site/reader036/viewer/2022062500/5681584e550346895dc5ab43/html5/thumbnails/4.jpg)
B1(a)
Outer RB
B2 B3 B4 B5 B6
Outer RBInner RB
(b)
Example of boundaries of outer and inner radiation belts as observed by Cluster CIS
![Page 5: Locations of boundaries of outer and inner radiation belts as observed by](https://reader036.vdocuments.site/reader036/viewer/2022062500/5681584e550346895dc5ab43/html5/thumbnails/5.jpg)
B2 (a)
Outer RB Outer RB
B1 B5 B6
Inner RBInner RB
B3 B4 (b)
Boundaries of outer and inner radiation belts as observed by Cluster CIS at different orbits
ORB
ORBIRB
![Page 6: Locations of boundaries of outer and inner radiation belts as observed by](https://reader036.vdocuments.site/reader036/viewer/2022062500/5681584e550346895dc5ab43/html5/thumbnails/6.jpg)
protons
electrons
4 8
32
Ener
gy
Thickness
4 Cluster8 Double Star
3040
Energy of penetrating electrons for HIA and CODIF at CLUSTER and Double Star
![Page 7: Locations of boundaries of outer and inner radiation belts as observed by](https://reader036.vdocuments.site/reader036/viewer/2022062500/5681584e550346895dc5ab43/html5/thumbnails/7.jpg)
Locations of boundaries for all events, MLT distribution
B1 and B6:outer boundary of outer RB
B2 and B5:inner boundary of outer RB
B3 and B4:outer boundary of inner RB
![Page 8: Locations of boundaries of outer and inner radiation belts as observed by](https://reader036.vdocuments.site/reader036/viewer/2022062500/5681584e550346895dc5ab43/html5/thumbnails/8.jpg)
Locations of boundaries for all events with activity indices
B1 and B6:outer boundary of outer RB
B2 and B5:inner boundary of outer RB
B3 and B4:outer boundary of inner RB
![Page 9: Locations of boundaries of outer and inner radiation belts as observed by](https://reader036.vdocuments.site/reader036/viewer/2022062500/5681584e550346895dc5ab43/html5/thumbnails/9.jpg)
Zoom 1
Zoom 2
Locations of boundaries for all events with SW parameters
Zoom 3B1 and B6:outer boundary of outer RB
B2 and B5:inner boundary of outer RB
B3 and B4:outer boundary of inner RB
Running Average
![Page 10: Locations of boundaries of outer and inner radiation belts as observed by](https://reader036.vdocuments.site/reader036/viewer/2022062500/5681584e550346895dc5ab43/html5/thumbnails/10.jpg)
Zoom 1Outer boundary of outer RB:- comes closer to Earth L=4- then moves tailward L=6
Time scale: 50 days
Before boundary dip:- Vsw from 430 to 540 km/sec- Kp to 5- Dst drop to -28 nT- AE to 700 nT- 2 peaks in Psw, 8 and 5 nPa
After boundary dip:- Vsw to 650 km/s- Kp to 5- Dst drop to -50 nT- AE to 800 nT- Psw at 3 nPa
![Page 11: Locations of boundaries of outer and inner radiation belts as observed by](https://reader036.vdocuments.site/reader036/viewer/2022062500/5681584e550346895dc5ab43/html5/thumbnails/11.jpg)
Zoom 2Outer boundary of outer RB:- comes closer to Earth L=4.5- then moves tailward L=7
Time scale: 40 days
Before boundary dip:- Vsw decreased to 300 km/sec- Kp to 2- Dst at +5 nT- AE to 300 nT- peak in Psw to 5.5 nPa and to 8 nPa at dip
After boundary dip:- Vsw to 650 km/s- Kp to 4- Dst drop to -25 nT- AE to 700 nT- Psw at 1 nPa
![Page 12: Locations of boundaries of outer and inner radiation belts as observed by](https://reader036.vdocuments.site/reader036/viewer/2022062500/5681584e550346895dc5ab43/html5/thumbnails/12.jpg)
Zoom 3
Outer boundary of outer RB:- comes closer to Earth L=5- then moves tailward L=7(7.5)
Time scale: 70 days
Picture is the same:
Before boundaries’ dip:peaks in Psw to 4 and 5.5 nPa
After boundaries’ dip:- Vsw jumps to 60 km/s- Kp to 4 and 3- Dst drops to -20 nT- AE to 600(500) nT
![Page 13: Locations of boundaries of outer and inner radiation belts as observed by](https://reader036.vdocuments.site/reader036/viewer/2022062500/5681584e550346895dc5ab43/html5/thumbnails/13.jpg)
Locations and width of slot region
Zoom ofslot widening
![Page 14: Locations of boundaries of outer and inner radiation belts as observed by](https://reader036.vdocuments.site/reader036/viewer/2022062500/5681584e550346895dc5ab43/html5/thumbnails/14.jpg)
Example of boundaries’ locations at Double Star
B2 B3 B0 B4 B5
Outer RB Inner RB Outer RBInner RB
![Page 15: Locations of boundaries of outer and inner radiation belts as observed by](https://reader036.vdocuments.site/reader036/viewer/2022062500/5681584e550346895dc5ab43/html5/thumbnails/15.jpg)
Locations of boundaries observed at Double Star
![Page 16: Locations of boundaries of outer and inner radiation belts as observed by](https://reader036.vdocuments.site/reader036/viewer/2022062500/5681584e550346895dc5ab43/html5/thumbnails/16.jpg)
Summary
- boundaries of radiation belts determined from background measurements on the instruments with energy ranges that do not cover the radiation belts’ energies provide valuable additional information that is useful for radiation belts’ model development and validation;
- solar wind pressure increases are important for the Earthward shift of the outer boundary of the outer belt;
- during intervals of low activity in the solar wind parameters, the slot region widens, which is consistent with weaker inward radial diffusion and weak local acceleration that can occur only at higher L-shells outside the plasmasphere.
![Page 17: Locations of boundaries of outer and inner radiation belts as observed by](https://reader036.vdocuments.site/reader036/viewer/2022062500/5681584e550346895dc5ab43/html5/thumbnails/17.jpg)
Locations of boundaries for all events, MLT distribution