Bulg. J. Phys. vol.48 no.4 (2021), pp. 320-337



Analysis of Associated and Non-Associated Type II Radio Bursts in Relationship to Flares and CMEs for Solar Cycle 24

Seema Pande, Deepak Pandey, Bimal Pande
Department of Physics, DSB Campus, Kumaun University, Nainital 263001, India
Abstract. In the present work two different wavelengths of type II radio bursts namely metric (m) and deca-hectometric (DH) have been statistically analyzed to understand their relationship with solar activities such as flares and CMEs for solar cycle 24 (December 2008 -- December 2016). Events have been classified into two groups on the basis of time delay between metric (m) and deca-hectometric (DH) type II radio bursts. Group A, represents the non-continuation of DH type II from m type II, whereas group B, represents the continuation of DH type II from m type II. A comparative study of the characteristics of type II bursts for both the groups has been undertaken. We have also analyzed the correlation between the associated flares and CMEs with both the wavelengths of type II radio bursts. For group A, we found that m type II have a significant correlation with associated X-ray flares and DH type II are correlated with both associated flares and CMEs. On the other hand, for group B both m and DH type II have a significant correlation with associated flares and CME parameters. These analyses indicate that m type II bursts for both the groups events are related to flares and DH type II bursts for both the groups are related to CMEs. We have also found that the average speed and spatial expansion of CMEs associated with DH type IIs are much higher than their usual values.

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