Statistics of Extreme Time‐Integrated Geomagnetic Activity. Issue 2 (19th January 2018)

• Record Type: Journal Article
• Authors: Mourenas, D.; Artemyev, A. V.; Zhang, X.‐J.
• Is Part Of: Geophysical research letters. Volume 45:Issue 2(2018)
• Page Start: 502
• Page End: 510
• Publication Date: 2018-01-19
• Subjects: space weather -- geomagnetic activity -- geomagnetic storm -- substorm -- radiation belt; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2017GL076828
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: A statistical analysis of the time‐integrated D s t index is performed over 1958–2007. The tail of the probability distribution of extreme time‐integrated D s t events, which occur during strong geomagnetic storms, can be precisely fitted by a power law function with upper cutoff, apparently not exceeded even by the 1859 Carrington event. This time‐integrated D s t is expected to be a reasonable proxy for maximum densities of MeV electrons in the heart of the outer radiation belt, which are known to pose a serious threat to satellites. During such strong events, a correlation is found between the time‐integrated levels of various physical quantities, such as interplanetary magnetic field B z, particle energy fluxes measured during injections in the magnetotail, geosynchronous ULF wave index, and geomagnetic activity in the inner magnetosphere, suggesting cumulative effects from successive disturbances. Key Points: Time‐integrated D s t during strong storms (IntDST) has a power law distribution with upper cutoff, and it depends on sunspot number IntDST is correlated with time‐integrated B z, magnetotail injection energy, A E, and ULF wave index during storms, suggesting cumulative effects The upper cutoff on IntDST may correspond to the presence of self‐limiting mechanisms in the solar‐magnetosphere system