1. 東京工業大学 理工学研究科 基礎物理学専攻 寺澤研究室 修士2年 樋口千夏
Statistical study of lightning activity: Periodicity and possible link with solar activity
東京工業大学　理工学研究科　基礎物理学専攻
寺澤研究室　修士2年　樋口千夏　

2. Contents Introduction Analysis and result discussion summary
・Solar activity
・Lightning activity
Analysis and result
discussion
summary 1

3. Contents Introduction Analysis and result discussion summary
・Solar activity
・Lightning activity
Analysis and result
discussion
summary

4. Variation on solar related parameter
F10.7
TSI
GCR
year
[count]
[W/m^2]
[ 10^-22W
/m^2Hz]
F10.7：solar radio flux(10.7cm)
proxy of UV flux
TSI：Total Solar Irradiance
GCR：Galactic Cosmic Ray
(Using neutron monitor data)
GCR
11-year period
min
max 2

5. Variation on solar related parameter
F10.7
PSD[/Hz]
TSI
GCR E
GCR
Solar flare
CMEs
period[day]
27~30-day period 3

6. Contents Introduction Analysis and result discussion summary
・Solar activity
・Lightning activity
Analysis and result
discussion
summary

7. Schumann resonance(SR)
(Sato,2003)
Freq[Hz]
Spectral intensity
7.8 14 20 5

8. 28-day periodicity of global lightning activity
＜observation＞
・at Syowa station in Antarctica (69.018S,39.506E)
・using search coil magnetometer
＜data＞
・2000/2~2003/1
・1~100Hz magnetic field data
＜SR power spectrum＞
(Sato,2003)
28-day 11
4～6
・~5,~10-day periodicity
⇒Correlated with
planetary wave activity
in the tropical region
・~28-day periodicity
⇒Influence of
solar activity?
Power spectrum
[day] 6

9. Cross-spectral analysis
between global lightning activity and solar parameters
(Sato,2003)
parameter
Period at the power-spectral peak[day]
Period at the cross-spectral peak[day]
Coherence
Phase(θSR-θpar)
[°]
(timelags[day])
F10.7
27.8
26.9
0.56
+20-90(2-7)
Cosmic Ray(CR)
30.7
30.5
0.47 -
Sun Spot Number(SSN)
27.7
27.0
0.57 Kp
26.2
25.6
0.53
0(0)
Dst
27.2
25.3
MeV electron
28.6
29.9
0.52
+110(8)
MeV ion
33.1
31.6
0.58
Tropical cloud coverage(>8km)
24.0
0.65
±180(0)
※Kp/Dst：Geomagnetic disturbance index 7

10. Possible scenario of solar influence on lightning activity
＜regional influence＞
Exp. UV
---temperature/wind modulation in stratosphere⇒vertical circulation⇒convective activity in troposphere
GCR
---ionization⇒CCN⇒cloud
---ionization⇒electric breakdown
Indirect influence
＜global influence＞
Exp.
GCR
---ionization⇒modulation of conductivity in atmosphere through global electric circuit
Direct influence 8

11. Madden – Julian Oscillation
What is MJO?
Madden – Julian Oscillation
--intraseasonal(20-60days) variability in the tropical atmosphere
--eastward propagation at 4-8m/s through the Indian and Pacific ocean
--characterized by pressure,cloud amount,rainfall
(Madden and Julian,1972) 9

12. Contents Introduction Analysis and result discussion summary
・Solar activity
・Lightning activity
Analysis and result
discussion
summary

13. 1.Lightning activity in Japan (45 prefectures)
＜data＞
・ extract from the weather record in JMA
・1989/1～2010/12
・in Japan(except Hokkaido and Okinawa)
Time profile of lightning data in Japan
Monthly distribution
[%]
where lightning activity occurs
The number of prefectures
year 10
month

14. ※method of Histogram analysis②  ③  ④  ⑤  ⑥  ① 
where lightning activity occur
The number of prefecture
day
period[day] 1 2 3 4 5 6
power
1（④）
1（⑥）
2（①⑤）
1（②）
1（③）
power
Period[day] 11

15. Histogram analysis of lightning activity in Japan(45)
(a)The number of prefectures
where lightning activity occurs：more 1
(b)more 5
(d)more 11
(e)more 12
(f)more 13
(g)more 14
(c)more 10
period[day]
power
― 3σ
― average
There is a ~29-day periodicity
in lightning which occur in more 12 prf. 12

16. 1.Lightning activity in Japan (32 prefectures)
＜data＞
・extract from the weather record in JMA
・1989/1～2010/12
・In Japan(except Hokkaido and Okinawa)
　・except the area along the sea of Japan
Time profile of lightning data in Japan
Monthly distribution
[%]
where lightning activity occur
The number of prefectures
year
month 13

17. Histogram analysis of lightning activity in Japan(32)
― 3σ
― average
― 3σ
― average
28-29-day
51-day
― 3σ
― average
＜data＞
・extract from the weather record in JMA
・1989/1～2010/12
・in Japan
・except the area along the sea of Japan
period[day]
power
・March-October
・the number of prefectures where lightning activity occurs: more 9
・the number of prefectures where lightning activity occurs: more 8
・the number of prefectures where lightning activity occurs: more 7
28-29,51-day periodicity
⇒influence of
solar activity?
MJO? 14

18. ※method of corrrelation analysis
34day 34 34 34
parameter
peak
・・・・　
lightning Ｃ ＋
parameter
・・・・　=
・・・・=　
lightning 15

19. Correlation between Ｆ10.7/GCR-lightning(J)
F10.7
time lag[day]
Lightning(J)
GCR
F10.7
time lag[day]
( ,Mar-Oct)
― 3σ
― 2σ 16

20. Correlation between F10.7-lightning
( /9,Mar-Oct)
time　lag[day]
Lightning(J)
F10.7
Lightning
In Africa
― 3σ
― 2σ
between F10.7 and
・lightning in Africa:
　positive correlation
(time lag:0day)
・lightning in Japan
(time lag:20day)
　negative correlation
(time lag:7day) 18

21. Possible scenario of solar influence on lightning activity
＜regional influence＞
Exp. UV
---temperature/wind modulation in stratosphere⇒vertical circulation⇒convective activity in troposphere
GCR
---ionization⇒CCN⇒cloud
---ionization⇒electric breakdown
Indirect influence
＜global influence＞
Exp.
GCR
---ionization⇒modulation of conductivity in atmosphere through global electric circuit ?
Direct influence 19

22. Contents Introduction Analysis and result discussion summary
・Solar activity
・Lightning activity
Analysis and result
discussion
summary

23. Similarity between spectrum of lightning and OLR in WPWP
(Takahashi,2010)
Lightning in Japan
OLR in WPWP
period[day]
PSD
― max
― min
PSD 20

24. Possible scenario for F10.7-MJO-lightning
~28-day
~40-60-day
F10.7
~27-day ?
MJO
~6m/s
~20day
~28-day
low
low
low
pressure
low
low
low
Africa
~12000km
Japan 21

25. Contents Introduction Analysis and result discussion summary
・Solar activity
・Lightning activity
Analysis and result
discussion
summary

26. summary ＜periodicity of lightning in Japan＞
・There are ~28,51-day periodicity for 3 sigma significance in lightning which occur in more 9 prefectures except along the sea of Japan .
⇒influence of solar activity or MJO ??
＜correlation between solar activity and lightning＞
・There is a good correlation between lightning in Japan and F10.7/GCR for 3 sigma significance.
The response is indirect influence of F10.7/GCR on lightning since there are response time lags.
・There is a good correlation with no time lag between lightning in Africa and F10.7 for ~3 sigma significance.
⇒possible link between F10.7, MJO and lightning 22