Bursty bulk flow intrusion to the inner plasma sheet as inferred from auroral observations

Author(s):  
K. Kauristie

2010 ◽  
Vol 115 (A5) ◽  
pp. n/a-n/a ◽  
Author(s):  
E. V. Panov ◽  
R. Nakamura ◽  
W. Baumjohann ◽  
V. A. Sergeev ◽  
A. A. Petrukovich ◽  
...  


2004 ◽  
Vol 22 (4) ◽  
pp. 1061-1075 ◽  
Author(s):  
A. Grocott ◽  
T. K. Yeoman ◽  
R. Nakamura ◽  
S. W. H. Cowley ◽  
H. U. Frey ◽  
...  

Abstract. On 07 September 2001 the Cluster spacecraft observed a "bursty bulk flow" event in the near-Earth central plasma sheet. This paper presents a detailed study of the coincident ground-based observations and attempts to place them within a simple physical framework. The event in question occurs at ~22:30 UT, some 10min after a southward turning of the IMF. IMAGE and SAMNET magnetometer measurements of the ground magnetic field reveal perturbations of a few tens of nT and small amplitude Pi2 pulsations. CUTLASS radar observations of ionospheric plasma convection show enhanced flows out of the polar cap near midnight, accompanied by an elevated transpolar voltage. Optical data from the IMAGE satellite also show that there is a transient, localised ~1 kR brightening in the UV aurora. These observations are consistent with the earthward transport of plasma in the tail, but also indicate the absence of a typical "large-scale" substorm current wedge. An analysis of the field-aligned current system implied by the radar measurements does suggest the existence of a small-scale current "wedgelet", but one which lacks the global scale and high conductivities observed during substorm expansions. Key words. Ionosphere (auroral ionosphere; ionospheremagnetosphere interactions; plasma convection)



2006 ◽  
Vol 122 (1-4) ◽  
pp. 301-311 ◽  
Author(s):  
Z. Vörös ◽  
W. Baumjohann ◽  
R. Nakamura ◽  
M. Volwerk ◽  
A. Runov


2015 ◽  
Vol 120 (3) ◽  
pp. 1832-1844 ◽  
Author(s):  
R. E. Ergun ◽  
K. A. Goodrich ◽  
J. E. Stawarz ◽  
L. Andersson ◽  
V. Angelopoulos


2016 ◽  
Vol 43 (5) ◽  
pp. 1854-1861 ◽  
Author(s):  
Tieyan Wang ◽  
Jinbin Cao ◽  
Huishan Fu ◽  
Xuejie Meng ◽  
M. Dunlop


2007 ◽  
Vol 14 (4) ◽  
pp. 535-541 ◽  
Author(s):  
Z. Vörös ◽  
W. Baumjohann ◽  
R. Nakamura ◽  
A. Runov ◽  
M. Volwerk ◽  
...  

Abstract. Bursty bulk flow associated magnetic fluctuations exhibit at least three spectral scaling ranges in the Earth's plasma sheet. Two of the three scaling ranges can be associated with multi-scale magnetohydrodynamic turbulence between the spatial scales from ~100 km to several RE (RE is the Earth's radius). These scales include the inertial range and below ~0.5 RE a steepened scaling range, theoretically not fully understood yet. It is shown that, in the near-Earth plasma sheet, the inertial range can be robustly identified only if multi-scale quasi stationary (MSQS) data intervals are selected. Multiple bursty flow associated magnetic fluctuations, however, exhibit 1/f type scaling indicating that large-scale fluctuations are controlled by multiple uncorrelated driving sources of the bulk flows (e.g. magnetic reconnection, instabilities).



2005 ◽  
Vol 48 (2) ◽  
pp. 277-283 ◽  
Author(s):  
Yu-Duan MA ◽  
Jin-Bin CAO ◽  
Guo-Cheng ZHOU ◽  
Zhen-Xin LIU ◽  
H. Reme ◽  
...  


2019 ◽  
Vol 872 (2) ◽  
pp. L26 ◽  
Author(s):  
M. Zhou ◽  
J. Huang ◽  
H. Y. Man ◽  
X. H. Deng ◽  
Z. H. Zhong ◽  
...  


2014 ◽  
Vol 119 (12) ◽  
pp. 9952-9961 ◽  
Author(s):  
Rongsheng Wang ◽  
Quanming Lu ◽  
Aimin Du ◽  
Rumi Nakamura ◽  
San Lu ◽  
...  


2007 ◽  
Vol 25 (6) ◽  
pp. 1405-1415 ◽  
Author(s):  
K. Snekvik ◽  
S. Haaland ◽  
N. Østgaard ◽  
H. Hasegawa ◽  
R. Nakamura ◽  
...  

Abstract. This article describes observations of a bursty bulk flow (BBF) in the outer central plasma sheet. The observations are made with the Cluster satellites, located approximately 19 RE downtail, close to the midnight sector in the Southern Hemisphere. 40–60 s after Cluster first detected the BBF, there was a large bipolar perturbation in the magnetic field. A Grad-Shafranov reconstruction has revealed that this is created by a field-aligned current at the flank of the BBF. Further analysis of the plasma moments has shown that the BBF has the properties of a depleted flux tube. Depleted flux tubes are an important theoretical model for how plasma and magnetic flux can be transported Earthward in the magnetotail as part of the Dungey cycle. The field aligned current is directed Earthward and is located at the dawn side of the BBF. Thus, it is consistent with the magnetic shear at the flank of an Earthward moving BBF. The total current has been estimated to be about 0.1 MA.



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