EISCAT observations of meteoric fragmentation Johan Kero, Csilla Szasz and Asta Pellinen-Wannberg...
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EISCAT observations of EISCAT observations of meteoric fragmentation meteoric fragmentation Johan Kero, Csilla Szasz and Asta Pellinen-Wannberg Johan Kero, Csilla Szasz and Asta Pellinen-Wannberg (Swedish Institute of Space Physics, Kiruna, Sweden) (Swedish Institute of Space Physics, Kiruna, Sweden) Gudmund Wannberg and Assar Westman Gudmund Wannberg and Assar Westman (EISCAT Scientific Association, Kiruna, Sweden) (EISCAT Scientific Association, Kiruna, Sweden) Tim e (s) R ange (km ) 26-N ov-2003 07:41:09 U T, line-of-sight vel. 33.9 and 33.6 km /s 0.05 0.1 0.15 0.2 0.25 195 196 197 198 199 200 201 202
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Transcript of EISCAT observations of meteoric fragmentation Johan Kero, Csilla Szasz and Asta Pellinen-Wannberg...
EISCAT observations ofEISCAT observations ofmeteoric fragmentationmeteoric fragmentation
Johan Kero, Csilla Szasz and Asta Pellinen-WannbergJohan Kero, Csilla Szasz and Asta Pellinen-Wannberg(Swedish Institute of Space Physics, Kiruna, Sweden)(Swedish Institute of Space Physics, Kiruna, Sweden)
Gudmund Wannberg and Assar WestmanGudmund Wannberg and Assar Westman(EISCAT Scientific Association, Kiruna, Sweden)(EISCAT Scientific Association, Kiruna, Sweden)
Arb
itra
ry e
ffect
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10
12
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Time (s)
Ra
ng
e (
km)
26-Nov-2003 07:41:09 UT, line-of-sight vel. 33.9 and 33.6 km/s
0.05 0.1 0.15 0.2 0.25
195
196
197
198
199
200
201
202
Outline of the talkOutline of the talk
• Meteoric fragmentation processes– From fireballs to dust...
• Observations with EISCAT– Fragmentation of small meteoroids...
Optical brightness pulsationsOptical brightness pulsations
2004-11-21 Leonid campaign with ALIS
ACKNOWLEDGEMENTS:
Björn Gustavsson and the ALIS team
Fireball flickering
Peekskill, October 9, 1992
Forms of fragmentationForms of fragmentation
Table from Bronshten, Physics of Meteoric Phenomena, Kluwer, 1983
EISCAT VHF: 2003-11-26
EISCAT UHF: 2004-12-21
2005-06-21
2005-09-22 (?)
26-Nov-2003 03:59:34 UT, line-of-sight vel. 3.1 km/s, 94 km altitude
0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2
0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.20
10
20
30
Time (s)
SN
R (
dB)
26-Nov-2003 02:15:24 UT, line-of-sight vel. 11.0 km/s, 95 km altitude
0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2
0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.20
10
20
30
Time (s)
SN
R (
dB)
980 985 990 995 1000 1005 1010
1
2
3
IPP
SN
R
( VKIR
= 26.3 km/s, VTRO
= 5.9 km/s, VSOD
= 11.8 km/s ) | V | = 38.1 km/s
KIRUNA
980 985 990 995 1000 1005 1010
20
40
60
IPP
SN
R
TROMS
980 985 990 995 1000 1005 1010
50
100
150
IPP
SN
R
SODANKYLÄ
980 985 990 995 1000 1005 1010
1
2
3
IPP
SN
R
( VKIR
= 26.3 km/s, VTRO
= 5.9 km/s, VSOD
= 11.8 km/s ) | V | = 38.1 km/s
KIRUNA
980 985 990 995 1000 1005 1010
20
40
60
IPP
SN
R
TROMS
980 985 990 995 1000 1005 1010
50
100
150
IPP
SN
R
SODANKYLÄ
988 990 992 994 996 998 1000 100260
70
80
90
100
110
120
IPP
Se
pa
ratio
n s
pe
ed
(m
/s)
TROMSSODANKYLÄ linear fit
TROMSØ
Assumption: One meteoroid broke up into two major fragments
Conclusions that may be drawn under the assumption is that the separation...
photo: Csilla Szasz
...distance was increasing with constant acceleration 0.88 km/s2
...occurred 0.1 s eller 4 km before they reached the centre of the radar beam
...distance was 1.6 m when they entered the radar beam
...distance was 9.6 m when they left the radar beam
