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)