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 sunspo...

We show that if the turbulent magnetic diffusivity used in solar dynamos is assumed to be ’quenched’ by increasing toroidal fields, much larger amplitude and more concentrated toroidal fields can be induced by differential rotation from an assumed poloidal field than if there is no quenching. This amplification and concentration mechanism is weakened and bounded by j × B feedbacks on the differ...

In developed turbulence, the effective magnetic pressure of a large-scale field (non-turbulent plus turbulent contributions) can become negative. This is known to lead to a large-scale instability in strongly stratified turbulence that produces spontaneous magnetic flux concentrations. Previous studies using a horizontal magnetic field resulted in elongated field concentrations with a strength ...

Time series of high-resolution images of the complex active region NOAA 10786 are studied. The observations were performed in G-band (430.5 nm) and in the nearby continuum (463.3 nm), on July 9, 2005 at the Swedish 1-meter Solar Telecope (SST) in La Palma. Granular proper motions in the surroundings of the sunspots have been quantified. A large-scale radial outflow in the velocity range 0.3 1 k...

Ground-based multichannel microwave radiometers (GMRs) can observe the atmospheric radiation brightness temperature at K-bands and V-bands provide humidity profiles with a relatively high temporal resolution. Currently, are operated in many countries to profiles. However, theoretical analysis showed that radiometer be used solar radiation. In this work, we improved control algorithm software of...

This paper describes automatic sunspot recognition and classification from satellite images. Some experimental results on learning sunspot classification using data mining techniques are presented. The classification scheme attempted was the seven-class Modified Zurich scheme. Daily images of the solar disk were taken from the NASA SOHO satellite’s MDI instrument and sunspots extracted using im...

We analyze a simple sunspot model that represents a standard securities market without sidebets on an exogenous sunspot event. The multiple self–fulfilling equilibria that arise in the model are based on investors’ uncertainty about other investors’ beliefs. Hence, these multiple equilibria are “endogenous sunspots.” We show that endogenous sunspots can arise even with complete markets to which...