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Statistical Analysis of Solar Geomagnetic Storm Occurrences
By:
Seth Sivak
Why We Study Geomagnetic Storms
• Blackouts
• Cell Phone Disruption
• Global Positioning Satellite Failure
• Danger to Satellites
• Danger to Astronauts
• Possible Danger to Airline Passengers
Questions That Needed Answers
• Are the maximums definitely at Equinox?
• Are March and April the maximums of the
year?
• Do Geomagnetic Storms occur randomly?
• When is the best time to turn on the radar?
Project Overview
• Madrigal Database (Millstone Hill)
• Kp and F10.7 cm Solar x-ray Flux
• 1950-2002
• Year, MDay, DNum, BHM
• Data Gaps
– F10.7 : 453 missing days (2.38%)
– Kp : 2 3-Hour missing elements (.00132%)
Broad View (52 Years)
• 11 Year Cycle for F10.7 X-Ray Flux
• Double Peaked Kp Cycle
• Downslide Peak Always Higher
• Correlation Between F10.7 and Kp
Year Breakdown Kp > 6
• Maximum in September
• Broad Peak in March and April
• Minimum during December and January
• Clear double peak on Equinox
Year Breakdown Kp > 8
• Maximum in September
• Peak in July
• Double Peak at Equinox
• Peak in March and April
• Minimum in December and January
Vernal Equinox
• All Peaks After Equinox
• Peak For Kp > 6 is April 4th
• Peak For Kp > 7 & Kp > 8 is April 1st
• High Peaks Follow in May
Autumnal Equinox
• Peak on Equinox• Sept. 22nd High
for Kp > 6 and Kp > 7
• Sept. 4th High for Kp > 7 and Kp > 8
July Maximum• July 15th-17th For all Kp
• Kp > 8 Almost Equal to Equinox
• Has not been explained
• Bastille Day Event (July 14th-16th 2000)
• Other Dates: – July 8, 1958
– July 15, 17, 1959
– July 16, 1960
– July 13, 14, 1961
– July 6, 1974
– July 13, 14, 1982
– July 13, 1991
Probability Kp > 6• Probability calculations
and why they are important
• Histogram maximum with high F10.7 found in March
• Probability maximums found in February, March, May, June, July, August, and September
Probability Kp > 7• F10.7 > 285
maximums are found in August and September
• F10.7 > 260 maximums are found in March, June, July, September and October
• F10.7 > 235 maximums are found in March, June, July and September
Probability Kp > 8• F10.7 > 285 maximums
found in September• F10.7 > 260 maximums
found in March, June, July, September and October
• F10.7 > 235 maximums found in March, June, July and September
• F10.7 > 210 maximums found in July
Time Series and Monthly Profiles
• Maximum in Summer Months
• Minimum in Winter Months
• Double Peak on Equinox
• Probability of storms increase with higher solar flux
BHM Results
• Peaks During Night Hours
• Minimum at 9 UT for all Kp levels
• Regular Kp > 6 and Kp > 7
• Random Kp > 8
• Some Physical Pattern Occurs
Model Data Axial Mechanism 1912
Equinoctial Mechanism 1959
Russel- McPheron 1973
Lyatsky 2001
Our Data 2002
Kp> 6 Kp> 7 Kp> 8
T = 365.25,
u = 0.717, T in day Gonzalez 1993
T = 365.35
u = 0.713,
u in nT2/day Gonzalez 1993
March 1 (24) March 3 (21) March 5 March 21 March 22 March 25 (23) March 25 (24) March 28 March 29 (23) March 31 (25) April 2 April 2 April 2 (25) April 4 April 5 April 16 (22) April 29 (23) May 2 Sept. 2 (29) Sept. 4 Sept. 4 Sept. 5 (24) Sept. 6 Sept. 18 (26) Sept. 21 Sept. 22 Sept. 22 Sept. 22 (23) Sept. 23 Sept. 23 (26) Sept. 28 (22) Oct. 5 Oct. 27 (21) Oct. 29 (21)
Conclusions
• Peak in September
• Peak in March
• Peak in July
• Peak During 18:00 UT - 3:00 UT (6 pm - 3 am)
• Probability for Large Storms With High F10.7
• Final Overview of All Models and Data
Future Plans
• Working till June 21st
• More research into the July Maximum (DST and Kp
1932)
• Writing Paper and submitting it to the Journal of
Undergraduate Research
• Web Site : www.haystack.mit.edu/~ssivak/haystack1.html
(under construction)