Skip to main content
Log in

Solar source longitudinal dependence of SEPs and their association with solar flares and radio-loud CMEs

  • Research
  • Published:
Astrophysics and Space Science Aims and scope Submit manuscript

Abstract

In this article we examine the occurrence probability of 104 major (\(\mathit{Ip}\), at energies > 10 MeV) solar energetic particle events (SEPs) and their peak intensity dependence on source longitude and on the characteristics of solar flares/radio-loud (RL) coronal mass ejections (CMEs) during the period November 1997–December 2014. We classified them into three sets of events based on the source longitude (L) of the associated solar flares: i) eastern side events (30°E < L ≤ 90°E), ii) disk center (30°E ≤ L ≤ 30°W), and iii) western side events (30°W < L ≤ 90°W). On average, the mean rise time and duration of SEPs are significantly larger for eastern side events (2168 min and 4.16 days, respectively) than the disk center (1338 min and 2.65 days, respectively) and western side events (662 min and 2.42 days, respectively). The mean peak intensity of SEPs from the disk center (103.56 pfu) is found to be greater than that of SEPs from the western (102.88 pfu) and eastern (102.53 pfu) sides, respectively. The western side events (54%) have significantly higher occurrence probability than the disk center (34%) and eastern side (12%). While there is no significant difference in most of the properties of solar flares and RL CMEs, the eastern side associated RL CMEs are highly decelerated (−29.37 m s−2) than the disk center (−17.44 m s−2) and western side (−9.09 m s−2) events. The relationship between peak intensity of SEPs and peak flux of solar flares shows that the correlation coefficients (\(\mathit{cc}\)) decrease from the eastern side to the western side: 0.65 (eastern), 0.51 (disk), and 0.35 (western). Interestingly, we found that there is a good correlation between the peak intensity of major SEPs and the speed of the CMEs (\(\mathit{cc} = 0.75\)) for disk center. From this study, we have concluded that gradualness depends on source longitude and increases from western to eastern side. It is also inferred that the relationship of peak intensity of SEP events with solar flare flux/CME speed is strongly dependent on source longitude.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5

Similar content being viewed by others

Data Availability

We collected the list of 143 major SEP events (peak intensity, Ip, at energies > 10 MeV) and their associated X- and M-class solar flares and radio-loud CMEs reported in the online Major SEP catalog from Coordinated Data Analysis Workshops (CDAW) (https://cdaw.gsfc.nasa.gov/CME_list/sepe/).

References

Download references

Acknowledgements

We greatly acknowledge the data support provided by various online data centers of NOAA and NASA. We would like to thank the Wind/WAVES and RSTN spectrograph teams for providing the type II catalogs. The SOHO/LASCO CME catalog is generated and maintained at the CDAW Data Center by NASA and The Catholic University of America in cooperation with the Naval Research Laboratory. SOHO is a project of international cooperation between ESA and NASA. We would like to acknowledge the core research grant support from the Department of Science and Technology – Science and Engineering Research Board, Government of India. F.No.CRG/2021/007496.

Author information

Authors and Affiliations

Authors

Contributions

The first, second, and third authors wrote the main text, and all authors reviewed the manuscript.

Corresponding author

Correspondence to P. Vijayalakshmi.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Prakash, O., Vijayalakshmi, P., Shanmugaraju, A. et al. Solar source longitudinal dependence of SEPs and their association with solar flares and radio-loud CMEs. Astrophys Space Sci 368, 83 (2023). https://doi.org/10.1007/s10509-023-04238-7

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1007/s10509-023-04238-7

Keywords

Navigation