scholarly journals Simultaneous observations of fluctuating cusp aurora and low-latitude magnetopause reconnection

2007 ◽  
Vol 112 (A11) ◽  
pp. n/a-n/a ◽  
Author(s):  
S. A. Fuselier ◽  
S. M. Petrinec ◽  
K. J. Trattner ◽  
M. Fujimoto ◽  
H. Hasegawa
Keyword(s):  
Low Latitude ◽  
Magnetopause Reconnection

scholarly journals On the longitudinal extent of magnetopause reconnection pulses

1996 ◽  
Vol 14 (9) ◽  
pp. 865-878 ◽  
Author(s):  
M. Lockwood ◽  
C. J. Davis
Keyword(s):  
Magnetic Reconnection ◽  
Local Time ◽  
Magnetic Local Time ◽  
Dispersion Characteristics ◽  
Low Latitude ◽  
Ion Injection ◽  
Reconnection Region ◽  
Transient Events ◽  
Magnetopause Reconnection

Abstract. The open magnetosphere model of cusp ion injection, acceleration and precipitation is used to predict the dispersion characteristics for fully pulsed magnetic reconnection at a low-latitude magnetopause X-line. The resulting steps, as would be seen by a satellite moving meridionally and normal to the ionospheric projection of the X-line, are compared with those seen by satellites moving longitudinally, along the open/closed boundary. It is shown that two observed cases can be explained by similar magnetosheath and reconnection characteristics, and that the major differences between them are well explained by the different satellite paths through the events. Both cases were observed in association with poleward-moving transient events seen by ground-based radar, as also predicted by the theory. The results show that the reconnection is pulsed but strongly imply it cannot also be spatially patchy, in the sense of isolated X-lines which independently are intermittently active. Furthermore they show that the reconnection pulses responsible for the poleward-moving events and the cusp ion steps, must cover at least 3 h of magnetic local time, although propagation of the active reconnection region may mean that it does not extend this far at any one instant of time.

scholarly journals Magnetopause reconnection rate estimates for Jupiter's magnetosphere based on interplanetary measurements at ~5AU

2006 ◽  
Vol 24 (1) ◽  
pp. 393-406 ◽  
Author(s):  
J. D. Nichols ◽  
S. W. H. Cowley ◽  
D. J. McComas
Keyword(s):  
Solar Cycle ◽  
High Latitude ◽  
Solar Rotation ◽  
Dynamic Pressure ◽  
Tail Length ◽  
Potential Drop ◽  
Reconnection Rate ◽  
Low Latitude ◽  
Open Flux ◽  
Magnetopause Reconnection

Abstract. We make the first quantitative estimates of the magnetopause reconnection rate at Jupiter using extended in situ data sets, building on simple order of magnitude estimates made some thirty years ago by Brice and Ionannidis (1970) and Kennel and Coroniti (1975, 1977). The jovian low-latitude magnetopause (open flux production) reconnection voltage is estimated using the Jackman et al. (2004) algorithm, validated at Earth, previously applied to Saturn, and here adapted to Jupiter. The high-latitude (lobe) magnetopause reconnection voltage is similarly calculated using the related Gérard et al. (2005) algorithm, also previously used for Saturn. We employ data from the Ulysses spacecraft obtained during periods when it was located near 5AU and within 5° of the ecliptic plane (January to June 1992, January to August 1998, and April to October 2004), along with data from the Cassini spacecraft obtained during the Jupiter flyby in 2000/2001. We include the effect of magnetospheric compression through dynamic pressure modulation, and also examine the effect of variations in the direction of Jupiter's magnetic axis throughout the jovian day and year. The intervals of data considered represent different phases in the solar cycle, such that we are also able to examine solar cycle dependency. The overall average low-latitude reconnection voltage is estimated to be ~230 kV, such that the average amount of open flux created over one solar rotation is ~500 GWb. We thus estimate the average time to replenish Jupiter's magnetotail, which contains ~300-500 GWb of open flux, to be ~15-25 days, corresponding to a tail length of ~3.8-6.5 AU. The average high-latitude reconnection voltage is estimated to be ~130 kV, associated with lobe "stirring". Within these averages, however, the estimated voltages undergo considerable variation. Generally, the low-latitude reconnection voltage exhibits a "background" of ~100 kV that is punctuated by one or two significant enhancement events during each solar rotation, in which the voltage is elevated to ~1-3 MV. The high-latitude voltages are estimated to be about a half of these values. We note that the peak values of order a few MV are comparable to the potential drop due to sub-corotating plasma flows in the equatorial magnetosphere between ~20 RJ and the magnetopause, such that during these periods magnetopause reconnection may have a significant effect on the otherwise rotationally dominated magnetosphere. Despite such variations during each solar rotation, however, the total amount of open flux produced during each solar rotation varies typically by less than ~30% on either side of the overall average for that epoch. The averages over individual data epochs vary over the solar cycle from ~600 GWb per solar rotation at solar maximum to ~400 GWb at solar minimum. In addition we show that the IMF sector with positive clock angle is favoured for reconnection when the jovian spin axis clock angle is also positive, and vice versa, although this effect represents a first order correction to the voltage, which is primarily modulated by IMF strength and direction.

Progress report on 21-cm observations at low latitude between longitudes (l 11) 0° and 66°

1967 ◽  
Vol 31 ◽  
pp. 177-179
Author(s):  
W. W. Shane
Keyword(s):  
Preliminary Report ◽  
Progress Report ◽  
Galactic Centre ◽  
Low Latitude ◽  
The Third ◽  
Introductory Lecture ◽  
Centre Region

In the course of several 21-cm observing programmes being carried out by the Leiden Observatory with the 25-meter telescope at Dwingeloo, a fairly complete, though inhomogeneous, survey of the regionl11= 0° to 66° at low galactic latitudes is becoming available. The essential data on this survey are presented in Table 1. Oort (1967) has given a preliminary report on the first and third investigations. The third is discussed briefly by Kerr in his introductory lecture on the galactic centre region (Paper 42). Burton (1966) has published provisional results of the fifth investigation, and I have discussed the sixth in Paper 19. All of the observations listed in the table have been completed, but we plan to extend investigation 3 to a much finer grid of positions.

Low‐Latitude Whistler‐Mode and Higher‐Latitude Z‐mode Emission at Jupiter Observed by Juno

2020 ◽  
Author(s):  
J. D. Menietti ◽  
T. F. Averkamp ◽  
M. Imai ◽  
W. S. Kurth ◽  
G. B. Clark ◽  
...  
Keyword(s):  
Low Latitude ◽  
Whistler Mode

Spatial Correlation and Diversity of Low-Latitude Multipath Multimode HF Skywave Radio Channels

2019 ◽  
Vol 9 (2) ◽  
pp. 110
Author(s):  
Indah Kurniawati ◽  
Gamantyo Hendrantoro ◽  
Wirawan Wirawan ◽  
Muhammad Taufik
Keyword(s):  
Spatial Correlation ◽  
Low Latitude ◽  
Radio Channels

Earliest Miocene calcareous nannofossil biostratigraphy from the low-latitude Pisco Basin (Peru)

Stratigraphy ◽  
2019 ◽  
Vol 16 (2) ◽  
pp. 87-105
Author(s):  
Emilia R. Belia ◽  
Kevin E. Nick ◽  
Erika Bedoya Agudelo ◽  
David K. Watkins
Keyword(s):  
Calcareous Nannofossil ◽  
Low Latitude ◽  
Calcareous Nannofossil Biostratigraphy

VLF/LF (Very Low Frequency/Low Frequency) Reflection Properties of the Low Latitude Ionosphere

1988 ◽  
Author(s):  
Wayne I. Klemetti ◽  
Paul A. Kossey ◽  
John E. Rasmussen ◽  
Maria Sueli Da Silveira Macedo Moura
Keyword(s):  
Low Frequency ◽  
Low Latitude ◽  
Very Low Frequency ◽  
Low Latitude Ionosphere
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