Skip to main content

Coronal Fe xiv Emission During the Whole Heliosphere Interval Campaign

Abstract

Solar Cycle 24 is having a historically long and weak start. Observations of the Fe xiv corona from the Sacramento Peak site of the National Solar Observatory show an abnormal pattern of emission compared to observations of Cycles 21, 22, and 23 from the same instrument. The previous three cycles have shown a strong, rapid ”Rush to the Poles” (previously observed in polar crown prominences and earlier coronal observations) in the parameter N(t,l,dt) (average number of Fe xiv emission features per day over dt days at time t and latitude l). Cycle 24 displays a weak, intermittent, and slow “Rush” that is apparent only in the northern hemisphere. If the northern Rush persists at its current rate, evidence from the Rushes in previous cycles indicates that solar maximum will occur in early 2013 or late 2012, at least in the northern hemisphere. At lower latitudes, solar maximum previously occurred when the time maximum of N(t,l,365) reached approximately 20° latitude. Currently, this parameter is at or below 30° and decreasing in latitude. Unfortunately, it is difficult at this time to calculate the rate of decrease in N(t,l,365). However, the southern hemisphere could reach 20° in 2011. Nonetheless, considering the levels of activity so far, there is a possibility that the maximum could be indiscernible.

This is a preview of subscription content, access via your institution.

References

  • Altrock, R.C.: 1997, Solar Phys. 170, 411.

    Article  ADS  Google Scholar 

  • Altrock, R.C.: 2003, Solar Phys. 216, 343.

    Article  ADS  Google Scholar 

  • Altrock, R.C.: 2007, Eos, Trans. Am. Geophys. Union 88(52), Fall Meeting Suppl., Abstract SH53A-1052.

  • Altrock, R.C., Howe, R., Ulrich, R.: 2008, In: Howe, R., Komm, R.W., Balasubramaniam, K.S., Petrie, G.J. (eds.) Subsurface and Atmospheric Influences on Solar Activity CS-383, Astron. Soc. Pac., San Francisco, 335.

    Google Scholar 

  • Fisher, R.R.: 1973, AFCRL-TR-73-0696, 15 pp.

  • Fisher, R.R.: 1974, Solar Phys. 36, 343.

    Article  ADS  Google Scholar 

  • Leroy, J.-L., Noens, J.-C.: 1983, Astron. Astrophys. 120, L1.

    ADS  Google Scholar 

  • Robbrecht, E., Wang, Y.-M., Sheeley, N.R. Jr., Rich, N.B.: 2010, Astrophys. J. 716, 693.

    Article  ADS  Google Scholar 

  • Rušin, V., Minarovjech, M., Saniga, M.: 2009, Contrib. Astron. Obs. Skalnaté Pleso 39, 71.

    ADS  Google Scholar 

  • Smartt, R.N.: 1982, In: Instrumentation in Astronomy IV, Proc. SPIE 331, 442.

    Google Scholar 

  • Trellis, M.: 1954, C. R. Acad. Sci. 239, 1119.

    Google Scholar 

  • Trellis, M.: 1963, C. R. Acad. Sci. 257, 52.

    Google Scholar 

  • Waldmeier, M.: 1957, Die Sonnenkorona II, Birkhäuser, Basel.

    Google Scholar 

  • Waldmeier, M.: 1964, Z. Astrophys. 59, 205.

    ADS  Google Scholar 

  • Wilson, P.R., Altrock, R.C., Harvey, K.L., Martin, S.F., Snodgrass, H.B.: 1988, Nature 333, 748.

    Article  ADS  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Richard C. Altrock.

Additional information

The Sun – Earth Connection near Solar Minimum

Guest Editors: M.M. Bisi, B.A. Emery, and B.J. Thompson

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Altrock, R.C. Coronal Fe xiv Emission During the Whole Heliosphere Interval Campaign. Sol Phys 274, 251–257 (2011). https://doi.org/10.1007/s11207-011-9714-9

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11207-011-9714-9

Keywords

  • Solar corona
  • Fe iv corona
  • Solar cycle