Coronal Mass Ejections from Sunspot and non-Sunspot Regions

نویسندگان

  • N. Gopalswamy
  • P. Mäkelä
چکیده

Coronal mass ejections (CMEs) originate from closed magnetic field regions on the Sun, which are active regions and quiescent filament regions. The energetic populations such as halo CMEs, CMEs associated with magnetic clouds, geoeffective CMEs, CMEs associated with solar energetic particles and interplanetary type II radio bursts, and shock-driving CMEs have been found to originate from sunspot regions. The CME and flare occurrence rates are found to be correlated with the sunspot number, but the correlations are significantly weaker during the maximum phase compared to the rise and declining phases. We suggest that the weaker correlation results from high-latitude CMEs from the polar crown filament regions that are not related to sunspots.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

The spatial relationship between active regions and coronal holes and the occurrence of intense geomagnetic storms throughout the solar activity cycle

We study the annual frequency of occurrence of intense geomagnetic storms (Dst < )100 nT) throughout the solar activity cycle for the last three cycles and ®nd that it shows di€erent structures. In cycles 20 and 22 it peaks during the ascending phase, near sunspot maximum. During cycle 21, however, there is one peak in the ascending phase and a second, higher, peak in the descending phase separ...

متن کامل

A Century of Polar Faculae Variations

The numbers of faculae at the poles of the Sun have been estimated from white-light images obtained at the Mount Wilson Observatory during 1985–2006 and combined with prior estimates extending back to 1906 when the observations began. The combined data show an 11-yr cyclic variation with faculae maxima occurring during sunspot minima in each of the past 10 sunspot cycles. Also, these numbers of...

متن کامل

Plasma Ejections from a Light Bridge in a Sunspot Umbra

We present conspicuous activities of plasma ejections along a light bridge of a stable and mature sunspot in NOAA 8971 on 2000 May 02. We found the ejections both in the Hα (10 K) images obtained with the Domeless Solar Telescope (DST) at Hida Observatory, and in the 171 Å (Fe ix/x, ∼106 K) images obtained with the Transition Region and Coronal Explorer (TRACE). Main characteristics of the ejec...

متن کامل

Magnetic Observations during the Recent Declining Phase of Solar Activity

Changes in the heliosphenc magnetic field during the rcccnt declining phase in solar activity are reviewed and compared with observations during past sunspot cycles. The stud y is based pnncipall y on data obtained by IMP-8 and Ulysses. The field magnitude is found to have increased during the declining phase until it reached a maximum value of 11 .5nT in = 1991.5, approximately two years after...

متن کامل

Solar Cycle Variation of Real CME Latitudes

With the assumption of radial motion and uniform longitudinal distribution of coronal mass ejections (CMEs), we propose a method to eliminate projection effects from the apparent observed CME latitude distribution. This method has been applied to SOHO LASCO data from 1996 January to 2006 December. As a result, we find that the real CME latitude distribution had the following characteristics: (1...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2009