Solar Sector Structure Correlations with SuperDARN Radar and EISCAT Svalbard Radar Data

Devin Huyghebaert and Kathryn McWilliamsDepartment of Physics and Engineering Physics

University of SaskatchewanJune 1, 2011

Outline

- Introduction - Solar sector structure - Quick overview of previous studies

- SuperDARN Results

- ISR Results

- Future Work

Introduction

(Akasofu, 1981)

- Solar current sheet

- Interplanetary Magnetic Field (IMF) directed one direction above current sheet, and opposite direction below current sheet.

- Earth finds itself above and below current sheet during orbit (Wilcox & Ness, 1967)

“away”

“away”“toward”

“toward”

Introduction

(Fairfield & Scudder, 1985)

- “towards” solar sectors connect southern polar cap upstream

- “away” solar sectors connect northern polar cap upstream

Introduction

- Summary of away/toward solar sectors for 10 years, 1998-2007

- Almost full solar cycle worth of data

Connections to Tropospheric Weather?

(Tinsley, 2000)

- Vorticity Area Index (VAI) - measure of low pressure troughs in Northern Hemisphere at latitudes >20°

- Past studies have shown correlations between solar sector boundary crossings and VAI

- Is there a link?

Past Study – Ionospheric Backscatter

day of month

Past Study – Ionospheric Backscatter

day of month

Results – Saskatoon SuperDARN Groundscatter 2003

-Groundscatter vs. ionospheric backscatter

- More groundscatter in “towards” sectors

- Occurs Distinctly in second half of 2003

- Same trend in ionospheric backscatter

Year

Hou

rly G

roun

dsca

tter

Cou

nt

t t t

a a a

(Gilles, 2006)

Results

t ttta aaat

Results – Saskatoon SuperDARN Groundscatter 2004

- 2004, solar sector structure no longer well defined

- difficult to find any correlation during this period

Year

Hou

rly G

roun

dsca

tter

Cou

nt

Results – SuperDARN Groundscatter 2003

90%

90%

70%

70%

50%50%

30%

30%

10% 10%

at ta

Results – SuperDARN Groundscatter 2004

90%90%

70%70%

50% 50%

30% 30%

10% 10%

t ta a

Results – SuperDARN Ionospheric Scatter 2003

90%

90%

70%

70%

50%

50%

30%

30%

10% 10%

t ta a

Results – Southern SuperDARN Groundscatter 2003

90%

70%50%

30%10%

t a

90%

70%50%

30%

10%

ta

Results – Solar Wind Data

- ACE Data

- 2003 shows an increase in solar wind velocity, and a decrease in solar wind density

SW Velocity

SW Density

Results – Incoherent Scatter Radar

- EISCAT Svalbard Radar (ESR) 42m field-aligned dish

- Opposite Correlations in E- and F- regions

- 27 day repetition of trend

2007 day 60-310

Electron Density

Lag Days

Hei

ght (

km)

Conclusions

- SuperDARN Groundscatter/Ionospheric Backscatter

- count increase in “towards” (southern polar cap connected)

- count decrease in “away” (northern polar cap connected)

- caused by propagation effects

- occurs in 2003, not evident in other years

- only evident in Northern Hemisphere

- often a peak within a day of the boundary crossing

- ISR Electron Density

- E- and F- region 27 day synodic solar rotation evident

Future Work

- Further analyze ISR data

- 2003, solar sector structure was well defined

- 2007, what is happening in the E- and F-regions?

- Analyze other ISR high-latitude locations (Svalbard,

Poker Flat, RISR-N, etc.)

- Link to NO density/D-region ionization?

- DMSP

References

Akasofu, S. -I., Energy coupling between the solar wind and the magnetosphere, Space Science Reviews, 28(2), pp. 121-190, 1981.

Fairfield, D. H., and Scudder, J. D., Polar rain: Solar coronal electrons in the Earth's magnetosphere, J. Geophys. Res., 90, pp. 4055, 1985.

Larsen, M.F., & M.C. Kelley, A study of an observed and forecasted meteorological index and its relation to the interplanetary magnetic field, Geophys. Res. Lett., 4:8, pp. 337-340, 1977.

Tinsley, B.A., Influence of solar wind on the global electric circuit, and inferred effects on cloud microphysics, temperature, and dynamics in the troposphere, Space Science Reviews, 94:1-2, pp.

231-258, 2000.

Tinsley, B. A., and R. A. Heelis, Correlations of atmospheric dynamics with solar activity evidence for a connection via the solar wind, atmospheric electricity, and cloud microphysics, J. Geophys.

Res., 98(D6), pp. 10,375–10,384, 1993.

Wilcox, J.M., Tropospheric circulation and interplanetary magnetic sector boundaries followed by MeV proton streams, Nature, 278, pp. 840-841, 1979.

Wilcox, J.M., and N.F. Ness, Solar source of the interplanetary sector structure, Solar Physics, 1:3-4, pp. 437-P445, 1967.

Results

- Attempted finding F- and E- region heights from groundscatter

- Problem with elevation angle

Results

- E- and F- regions have the same sign correlation

- 27 day repetition of trend

2007 day 60-310

Ion Temperature

Slide 1Slide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14Slide 15Slide 16Slide 17Slide 18Slide 19Slide 20Slide 21Slide 22