Explicit IMF By‐Dependence of Energetic Protons and the Ring Current

Holappa, Lauri; Buzulukova, N.

doi:10.1029/2022gl098031

Cited by 6 publications

(5 citation statements)

References 75 publications

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“…The symmetry of the FACs across the noon-night meridional plane breaks in the ionosphere for dawn–dusk IMFs, unlike those cases in which the IMF is purely northward or southward. Using satellite observations and a global MHD model coupled with a ring current model, Holappa et al 29 found that in the northern hemisphere, the flux of energetic magnetospheric protons and the growth rate of the circulation are larger for IMF 0 than for IMF 0. The above studies show that the magnetospheric structure and magnetic reconnection are affected by the IMF component, and the energy transfer characteristics across the magnetopause are also impacted.…”

Section: Introductionmentioning

confidence: 99%

Energy transfer across magnetopause under dawn–dusk IMFs

Zhang

Wang

2023

Sci Rep

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A parametric study on the energy transfer of the solar wind across the magnetopause entering the magnetosphere is conducted using a global magnetohydrodynamic numerical simulation. The characteristics of the mechanical and electromagnetic energy distribution under the dawn–dusk interplanetary magnetic fields (IMFs) are investigated by analyzing magnetic reconnection and viscous effect, and compared with the radial and north–south IMFs. It is shown that (1) the interactions at the magnetopause and the transfer of energy across this boundary move in relation to the IMF orientation. (2) For the duskward IMF, the mechanical energy flow clearly enters the equatorial and low-latitude regions on the dayside, and the electromagnetic energy flow has a small inflow on the equatorial and low latitudes of the dayside. A significant energy inflow appears on the dawn side in the northern hemisphere and the dusk side in the southern hemisphere near the polar cusp. (3) The energy distribution characteristics across the magnetopause under dawn–dusk IMFs are mirror symmetric about the $$Y=0$$ Y = 0 plane. (4) For a magnetic field of 5 nT, the electromagnetic energy input under the dawn–dusk IMFs is twice as large as the mechanical energy and the electromagnetic energy under the radial IMF, which is five times as large as the electromagnetic energy during the pure northward IMF, but only half as large as the electromagnetic energy under the pure southward IMF. The mechanical energy input under dawn–dusk IMFs has the same magnitude as that under radial and north–south IMFs. The magnitude of the energy transfer rate for the dawn IMF and dusk IMF (about 3.5%) is between 1.71% for the northward IMF and 4.95% for the southward IMF, but higher than 2.22% for the radial IMF. The Akasofu-type energy-coupling formula, $$\varepsilon$$ ε , underestimates the energy input from the solar wind under $$B_{y}$$ B y dominated IMF.

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Section: Introductionmentioning

confidence: 99%

Energy transfer across magnetopause under dawn–dusk IMFs

Zhang

Wang

2023

Sci Rep

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“…(2021b) noted that this By sign dependence is very strong in the winter hemisphere, but it is weak in the summer hemisphere, and is much stronger in the westward electrojet than in the eastward electrojet. Holappa and Buzulokova (2022) noted that the physical mechanisms of IMF By effects, which apply not only to auroral zone electron precipitation and ionospheric conductance but also to the fluxes of energetic magnetosphere protons and the growth rate of the ring current, are still not fully understood.…”

Section: Discussionmentioning

confidence: 99%

Geomagnetic Disturbances That Cause GICs: Investigating Their Interhemispheric Conjugacy and Control by IMF Orientation

et al. 2022

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“…(2020) analyzed the electron flux data in three different MLT bins, each spanning 8 hr: 20–04 MLT (night), 04–12 MLT (dawn), and 12–20 MLT (dusk) in order to study potential MLT dependence of electron flux on IMF B y effect. Additionally, Holappa and Buzulukova (2022) studied the IMF B y effect on the energetic proton flux specifically in the dusk sector, focusing on the 12 to 24 MLT interval. In this work, the MLT of peak PEJ is used to define the events, following previous works (e.g., Wang & Lühr, 2023, 2024).…”

Section: Data and Processing Methodsmentioning

confidence: 99%

Interplanetary Magnetic Field B_y Effects on the Strength and Latitude of Field‐Aligned Currents in Different Magnetic Local Time Sectors

Wang,

Sun,

Lühr

2024

JGR Space Physics

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In this work, IMF By effects on field‐aligned currents (FACs) are examined in different local time sectors, seasons, and hemispheres. At dusk and 09–14 MLT, when the eastward polar electrojet (PEJ) prevails, the northern FACp (poleward side FACs) are stronger when IMF By < 0 than when IMF By > 0. Conversely, at dawn, 21–02 MLT, and 09–14 MLT with westward PEJ, the northern FACp are stronger with IMF By > 0 compared to IMF By < 0. The southern FACp shows a reversed relationship with IMF By direction. The dependence of FACe (equatorward side FACs) on IMF By is weaker, except for the midday FACe, which shows opposite variations with respect to IMF By when compared to FACp. Stronger IMF By effect is observed in local summer in most of local times. The northern FACs are located at higher latitude for IMF By > 0 than for IMF By < 0 in local times with eastward PEJ, while the opposite trend is observed in other local times and in the Southern Hemisphere. The hemispheric difference in the peak latitude of FACs demonstrates an inverse relationship with its intensity, with stronger FACs located at lower latitudes. Overall, the local time and hemispheric differences in FACs strength and latitude are discussed in the context of interhemispheric field‐aligned currents linked to IMF By.

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Explicit IMF B_y‐Dependence of Energetic Protons and the Ring Current

Cited by 6 publications

References 75 publications

Energy transfer across magnetopause under dawn–dusk IMFs

Energy transfer across magnetopause under dawn–dusk IMFs

Geomagnetic Disturbances That Cause GICs: Investigating Their Interhemispheric Conjugacy and Control by IMF Orientation

Interplanetary Magnetic Field B_y Effects on the Strength and Latitude of Field‐Aligned Currents in Different Magnetic Local Time Sectors

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Explicit IMF By‐Dependence of Energetic Protons and the Ring Current

Cited by 6 publications

References 75 publications

Energy transfer across magnetopause under dawn–dusk IMFs

Energy transfer across magnetopause under dawn–dusk IMFs

Geomagnetic Disturbances That Cause GICs: Investigating Their Interhemispheric Conjugacy and Control by IMF Orientation

Interplanetary Magnetic Field By Effects on the Strength and Latitude of Field‐Aligned Currents in Different Magnetic Local Time Sectors

Contact Info

Product

Resources

About

Explicit IMF B_y‐Dependence of Energetic Protons and the Ring Current

Interplanetary Magnetic Field B_y Effects on the Strength and Latitude of Field‐Aligned Currents in Different Magnetic Local Time Sectors