Geomagnetic jerk features produced using synthetic core flow models

Pinheiro, Katia; Amit, Hagay; Terra-Nova, Filipe

doi:10.1016/j.pepi.2019.03.006

Cited by 6 publications

(5 citation statements)

References 68 publications

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“…If DH20's conclusion that the EYO is excited by the jerks is correct, the SYO is more likely to be excited by the jerks, which is in contrast with another conclusion from DH20. In addition, considering that the jerk duration time may even be up to 4.7 years (Pinheiro et al, 2019), our results also indicated that the EYO could not be used to predict jerks (differ from DH20). We further compare the jerks with the sudden changes in the SYO/EYO time series (similar to Holme and de Viron, 2013) and their excitation time series (similar to Ding, 2019), the results do demonstrate that the jerks seem to be related to the excitations of the SYO/EYO (see Figures 7 and 9).…”

Section: Discussionmentioning

confidence: 79%

“…(2019), jerks may be somewhat smoother than what is often considered, and Pinheiro et al. (2019) found that the jerk duration time can be up to 4.7 years. Hence, even with the above, we do not recommend such comparison.…”

Section: The Relationship Between Jerks and Eyo/syomentioning

confidence: 99%

“…According to Cox et al (2016) and Pinheiro et al (2019), jerks may be somewhat smoother than what is often considered, and Pinheiro et al 2019found that the jerk duration time can be up to 4.7 years. Hence, DING ET AL.…”

Section: 1029/2020jb020990mentioning

confidence: 99%

“…According to Cox et al (2016) and Pinheiro et al (2019) 2b) obtained from the N_G time series, and the jerk events in recent decades; the green curves denote the obtained N_E (EYO) and N_S (SYO), which are shown in Figure 4a. The yellow areas denote the 13 jerks (with one year uncertainty) selected in DH20, some of which were also used in Holme and de Viron (2013) (the corresponding year is marked with blue font at the top of (a)).…”

Section: Comparing Jerks With the Syo/eyo In The Time Domainmentioning

confidence: 99%

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New Evidence for the Fluctuation Characteristics of Intradecadal Periodic Signals in Length‐Of‐Day Variation

Ding

Shen

2021

JGR Solid Earth

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The fluctuation characteristics and excitations of the intradecadal changes in the length-of-day variation (∆LOD) were thought to be related to the secular variations in the core geomagnetic field and hence help to constrain the magnetic field strength in the core as well as to understand the mechanism driving the Earth's core-mantle interactions (e.g., R. S. Gross, 2015; Mound & Buffett, 2006). Two periodic signals have been detected from the ∆LOD in the intradecadal period band (i.e., the 5-10 years period band), an approximately six year oscillation (SYO, e.g., Holme & de Viron, 2013; Liao & Greiner-Mai, 1999) and an approximately 8.5 years oscillation (EYO, Ding, 2019). Their fluctuation characteristics are thought to help determine their possible mechanism (e.g., Gillet et al., 2010), but the fluctuation characteristics of these two signals are still controversial. Liao and Greiner-Mai (1999) first found a nearly stable ∼5.8 years oscillation in the 1970-1990 ∆LOD (see their Figure 5a) and suggested that the Southern Oscillation Index may have had some correlation with it. Abarca del Rio et al. (2000) also showed that the 6-7 years oscillation had no stable decreasing trend in the 1900-2000 time span (see their Figures 3 and 5), and its fluctuation characteristic was similar to a

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Section: Discussionmentioning

confidence: 79%

Section: The Relationship Between Jerks and Eyo/syomentioning

confidence: 99%

Section: 1029/2020jb020990mentioning

confidence: 99%

Section: Comparing Jerks With the Syo/eyo In The Time Domainmentioning

confidence: 99%

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New Evidence for the Fluctuation Characteristics of Intradecadal Periodic Signals in Length‐Of‐Day Variation

Ding

Shen

2021

JGR Solid Earth

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“…Huguet et al, 2016), local time series of the surface field (e.g. Trindade et al, 2018) or geomagnetic jerks (Pinheiro et al, 2019).…”

Section: Discussionmentioning

confidence: 99%

Polar caps and auroral zones under idealized axisymmetric magnetic fields

Parentis

Zossi

Amit

et al. 2021

Advances in Space Research

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The geomagnetic field, modified by the solar wind, determines the shape, area and location of polar caps and auroral zones, among other magnetosphere and upper atmosphere characteristics. Since the field varies greatly with time it is of interest to analyze polar caps and auroral zones variations linked to magnetic field variations of intensity and pattern. Polar caps and auroral zones locations and areas for various single harmonic axial field configurations are obtained analytically assuming a simple magnetopause model. As the axial degree n increases, the polar caps and auroral zones total number, given by n + 1 and 2n respectively, also increase. However, their total areas decrease from a larger value in the case of an axial dipole to a minimum for an axial octupole (n = 3), and then increase for increasing degrees. The increasing rate is much higher in the auroral zones case to the point that it exceeds the dipolar value at n = 5 while in the polar caps case this occurs at n = 8. The absolute latitudes of the auroral zones and polar caps that reside around the geographical poles increase with axial degree. Our results represent an end-member case of the evolution of auroral zones and polar caps during polarity reversals if the transition involves axial dipole energy cascade to higher axial degrees. Evidence for such an energy transfer is found in the historical record of the geomagnetic secular variation.

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