Statistical characteristics of CMEs and flares associated with solar type II radio bursts

A. Shanmugaraju; Y. J. Moon; M. Dryer; S. Umapathy

doi:10.1023/B:SOLA.0000006902.89339.e4

Statistical characteristics of CMEs and flares associated with solar type II radio bursts

A. Shanmugaraju
, Y. J. Moon
, M. Dryer
, S. Umapathy

Research output: Contribution to journal › Article › peer-review

25 Citations (Scopus)

Abstract

We have made a comprehensive statistical study of the characteristics of 290 SOHO/LASCO CMEs and their associated GOES-8 X-ray flares (> C1 class) during the period January 1997-December 2000 of solar cycle 23's rise to maximum. These events were classified into mainly three groups (Group noII - not associated with type IIs, Group II - associated with type IIs, Group DH - associated with deca/hectametric type IIs). To understand the physical characteristics associated with the origin of metric type IIs, we have examined the important parameters of CMEs and flares such as the speed and width of CMEs, and the rise time, duration and importance of flares. Major results from the present study are: (i) CMEs with type IIs are relatively bigger in size (mean width = 93°) with higher speed (mean = 704 km s^-1 than those of the CMEs without type IIs (mean width = 54° and mean speed = 505 km s ^-1; (ii) flares with type IIs have longer rise time (mean = 16.1 min) and duration (mean = 32.7 min) than the mean values (rise time = 11.8 min; duration = 22.4 min) of flares without type IIs. Also the significant differences between Group noII and Group II have been identified from results of the Student's t-test. It may be emphasized that the impulsiveness of type II flares is found to be higher than that of no type II flares. However, there are exceptional cases: among the 229 CMEs without type IIs, nearly 50% (115/229) of CMEs in Group noII had speeds > 400 km s^-1, and nearly 10% (22/229) of CMEs had widths between 100-200 deg. Similarly, in this group, there are more than 10% (30/229) flares of class > M1 and nearly 7% (17/229) of flares with duration > 45 min. These results may imply that a special condition, like 'low Alfvén speed', as a favoring environment for producing MHD shocks, is necessary to generate metric type IIs. The CMEs and flares associated with both metric as well as DH type IIs are likely to be the most energetic events. The mean acceleration of flare-associated DH CMEs tends to be positive in contrast to that of all DH CMEs.

Original language	English
Pages (from-to)	301-317
Number of pages	17
Journal	Solar Physics
Volume	217
Issue number	2
DOIs	https://doi.org/10.1023/B:SOLA.0000006902.89339.e4
Publication status	Published - Nov 2003

Bibliographical note

Funding Information:
The authors wish to thank the referee, Dr Bojan Vršnak, for many useful and constructive suggestions which improved the quality of this paper. We are also grateful to the various catalogs available on the Internet and to their open data policy. Y.-J.M. has been supported by a MURI grant of AFOSR and by NRL M10104000059-01J000002500 of the Korean government. M.D. has been partially supported by a U.S. DoD/USAF/UPOS project (via the University of Alaska at Fairbanks, Geophysical Institute) and by a NASA/LWS Grant NAG5-12527 to Exploration Physics International, Inc. The CME catalog we have used is generated and maintained by the Center for Solar Physics and Space Weather, The Catholic University of America in cooperation with the Naval Research Laboratory and NASA. SOHO is a project of international cooperation between ESA and NASA.

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Cite this

@article{c147185b2b054b1395ba04bf5e78b503,

title = "Statistical characteristics of CMEs and flares associated with solar type II radio bursts",

abstract = "We have made a comprehensive statistical study of the characteristics of 290 SOHO/LASCO CMEs and their associated GOES-8 X-ray flares (> C1 class) during the period January 1997-December 2000 of solar cycle 23's rise to maximum. These events were classified into mainly three groups (Group noII - not associated with type IIs, Group II - associated with type IIs, Group DH - associated with deca/hectametric type IIs). To understand the physical characteristics associated with the origin of metric type IIs, we have examined the important parameters of CMEs and flares such as the speed and width of CMEs, and the rise time, duration and importance of flares. Major results from the present study are: (i) CMEs with type IIs are relatively bigger in size (mean width = 93°) with higher speed (mean = 704 km s-1 than those of the CMEs without type IIs (mean width = 54° and mean speed = 505 km s -1; (ii) flares with type IIs have longer rise time (mean = 16.1 min) and duration (mean = 32.7 min) than the mean values (rise time = 11.8 min; duration = 22.4 min) of flares without type IIs. Also the significant differences between Group noII and Group II have been identified from results of the Student's t-test. It may be emphasized that the impulsiveness of type II flares is found to be higher than that of no type II flares. However, there are exceptional cases: among the 229 CMEs without type IIs, nearly 50\% (115/229) of CMEs in Group noII had speeds > 400 km s-1, and nearly 10\% (22/229) of CMEs had widths between 100-200 deg. Similarly, in this group, there are more than 10\% (30/229) flares of class > M1 and nearly 7\% (17/229) of flares with duration > 45 min. These results may imply that a special condition, like 'low Alfv{\'e}n speed', as a favoring environment for producing MHD shocks, is necessary to generate metric type IIs. The CMEs and flares associated with both metric as well as DH type IIs are likely to be the most energetic events. The mean acceleration of flare-associated DH CMEs tends to be positive in contrast to that of all DH CMEs.",

author = "A. Shanmugaraju and Moon, \{Y. J.\} and M. Dryer and S. Umapathy",

note = "Funding Information: The authors wish to thank the referee, Dr Bojan Vr{\v s}nak, for many useful and constructive suggestions which improved the quality of this paper. We are also grateful to the various catalogs available on the Internet and to their open data policy. Y.-J.M. has been supported by a MURI grant of AFOSR and by NRL M10104000059-01J000002500 of the Korean government. M.D. has been partially supported by a U.S. DoD/USAF/UPOS project (via the University of Alaska at Fairbanks, Geophysical Institute) and by a NASA/LWS Grant NAG5-12527 to Exploration Physics International, Inc. The CME catalog we have used is generated and maintained by the Center for Solar Physics and Space Weather, The Catholic University of America in cooperation with the Naval Research Laboratory and NASA. SOHO is a project of international cooperation between ESA and NASA.",

year = "2003",

month = nov,

doi = "10.1023/B:SOLA.0000006902.89339.e4",

language = "English",

volume = "217",

pages = "301--317",

journal = "Solar Physics",

issn = "0038-0938",

publisher = "Springer Netherlands",

number = "2",

}

TY - JOUR

T1 - Statistical characteristics of CMEs and flares associated with solar type II radio bursts

AU - Shanmugaraju, A.

AU - Moon, Y. J.

AU - Dryer, M.

AU - Umapathy, S.

N1 - Funding Information: The authors wish to thank the referee, Dr Bojan Vršnak, for many useful and constructive suggestions which improved the quality of this paper. We are also grateful to the various catalogs available on the Internet and to their open data policy. Y.-J.M. has been supported by a MURI grant of AFOSR and by NRL M10104000059-01J000002500 of the Korean government. M.D. has been partially supported by a U.S. DoD/USAF/UPOS project (via the University of Alaska at Fairbanks, Geophysical Institute) and by a NASA/LWS Grant NAG5-12527 to Exploration Physics International, Inc. The CME catalog we have used is generated and maintained by the Center for Solar Physics and Space Weather, The Catholic University of America in cooperation with the Naval Research Laboratory and NASA. SOHO is a project of international cooperation between ESA and NASA.

PY - 2003/11

Y1 - 2003/11

N2 - We have made a comprehensive statistical study of the characteristics of 290 SOHO/LASCO CMEs and their associated GOES-8 X-ray flares (> C1 class) during the period January 1997-December 2000 of solar cycle 23's rise to maximum. These events were classified into mainly three groups (Group noII - not associated with type IIs, Group II - associated with type IIs, Group DH - associated with deca/hectametric type IIs). To understand the physical characteristics associated with the origin of metric type IIs, we have examined the important parameters of CMEs and flares such as the speed and width of CMEs, and the rise time, duration and importance of flares. Major results from the present study are: (i) CMEs with type IIs are relatively bigger in size (mean width = 93°) with higher speed (mean = 704 km s-1 than those of the CMEs without type IIs (mean width = 54° and mean speed = 505 km s -1; (ii) flares with type IIs have longer rise time (mean = 16.1 min) and duration (mean = 32.7 min) than the mean values (rise time = 11.8 min; duration = 22.4 min) of flares without type IIs. Also the significant differences between Group noII and Group II have been identified from results of the Student's t-test. It may be emphasized that the impulsiveness of type II flares is found to be higher than that of no type II flares. However, there are exceptional cases: among the 229 CMEs without type IIs, nearly 50% (115/229) of CMEs in Group noII had speeds > 400 km s-1, and nearly 10% (22/229) of CMEs had widths between 100-200 deg. Similarly, in this group, there are more than 10% (30/229) flares of class > M1 and nearly 7% (17/229) of flares with duration > 45 min. These results may imply that a special condition, like 'low Alfvén speed', as a favoring environment for producing MHD shocks, is necessary to generate metric type IIs. The CMEs and flares associated with both metric as well as DH type IIs are likely to be the most energetic events. The mean acceleration of flare-associated DH CMEs tends to be positive in contrast to that of all DH CMEs.

AB - We have made a comprehensive statistical study of the characteristics of 290 SOHO/LASCO CMEs and their associated GOES-8 X-ray flares (> C1 class) during the period January 1997-December 2000 of solar cycle 23's rise to maximum. These events were classified into mainly three groups (Group noII - not associated with type IIs, Group II - associated with type IIs, Group DH - associated with deca/hectametric type IIs). To understand the physical characteristics associated with the origin of metric type IIs, we have examined the important parameters of CMEs and flares such as the speed and width of CMEs, and the rise time, duration and importance of flares. Major results from the present study are: (i) CMEs with type IIs are relatively bigger in size (mean width = 93°) with higher speed (mean = 704 km s-1 than those of the CMEs without type IIs (mean width = 54° and mean speed = 505 km s -1; (ii) flares with type IIs have longer rise time (mean = 16.1 min) and duration (mean = 32.7 min) than the mean values (rise time = 11.8 min; duration = 22.4 min) of flares without type IIs. Also the significant differences between Group noII and Group II have been identified from results of the Student's t-test. It may be emphasized that the impulsiveness of type II flares is found to be higher than that of no type II flares. However, there are exceptional cases: among the 229 CMEs without type IIs, nearly 50% (115/229) of CMEs in Group noII had speeds > 400 km s-1, and nearly 10% (22/229) of CMEs had widths between 100-200 deg. Similarly, in this group, there are more than 10% (30/229) flares of class > M1 and nearly 7% (17/229) of flares with duration > 45 min. These results may imply that a special condition, like 'low Alfvén speed', as a favoring environment for producing MHD shocks, is necessary to generate metric type IIs. The CMEs and flares associated with both metric as well as DH type IIs are likely to be the most energetic events. The mean acceleration of flare-associated DH CMEs tends to be positive in contrast to that of all DH CMEs.

UR - https://www.scopus.com/pages/publications/3543082085

U2 - 10.1023/B:SOLA.0000006902.89339.e4

DO - 10.1023/B:SOLA.0000006902.89339.e4

M3 - Article

AN - SCOPUS:3543082085

SN - 0038-0938

VL - 217

SP - 301

EP - 317

JO - Solar Physics

JF - Solar Physics

IS - 2

ER -

Statistical characteristics of CMEs and flares associated with solar type II radio bursts

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Bibliographical note

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