Afternoon subauroral proton precipitation resulting from ring current—plasmasphere interaction

2005 ◽  
pp. 85-99 ◽  
Author(s):  
M. Spasojević ◽  
M. R. Thomsen ◽  
P. J. Chi ◽  
B. R. Sandel
Keyword(s):  
Ring Current ◽  
Proton Precipitation

On the energy dependence of the ring current proton precipitation

1977 ◽  
Vol 25 (8) ◽  
pp. 757-763 ◽  
Author(s):  
F. Søraas ◽  
J.Å. Lundblad ◽  
B. Hultqvist
Keyword(s):  
Energy Dependence ◽  
Ring Current ◽  
Proton Precipitation

Modeling ring current proton precipitation by electromagnetic ion cyclotron waves during the May 14-16, 1997, storm

2001 ◽  
Vol 106 (A1) ◽  
pp. 7-22 ◽  
Author(s):  
V. K. Jordanova ◽  
C. J. Farrugia ◽  
R. M. Thorne ◽  
G. V. Khazanov ◽  
G. D. Reeves ◽  
...  
Keyword(s):  
Ring Current ◽  
Ion Cyclotron Waves ◽  
Ion Cyclotron ◽  
Proton Precipitation ◽  
Electromagnetic Ion Cyclotron Waves

Ring current model of the naphthalene molecule

1997 ◽  
Vol 92 (3) ◽  
pp. 609-617 ◽  
Author(s):  
RICCARDO ZANASI ◽  
PAOLO LAZZERETTI
Keyword(s):  
Ring Current ◽  
Current Model ◽  
Naphthalene Molecule

Investigation of Ring Current/Storm Dynamics

1991 ◽  
Author(s):  
H. L. Collin ◽  
J. B. Cladis ◽  
J. M. Quinn
Keyword(s):  
Ring Current ◽  
Storm Dynamics

Survey of Ring Current Composition During Magnetic Storms

1998 ◽  
Author(s):  
M. Grande ◽  
C. H. Perry ◽  
A. Hall ◽  
J. Fennell ◽  
B. Wilken
Keyword(s):  
Ring Current ◽  
Magnetic Storms

scholarly journals Decay of the Dst field of geomagnetic disturbance after substorm onset and its implication to storm-substorm relation

1996 ◽  
Vol 14 (6) ◽  
pp. 608-618 ◽  
Author(s):  
T. Iyemori ◽  
D. R. K. Rao
Keyword(s):  
Ring Current ◽  
Geomagnetic Storms ◽  
Sharp Decrease ◽  
Geomagnetic Disturbance ◽  
Substorm Onset ◽  
Significant Development ◽  
H Index ◽  
Magnetospheric Tail ◽  
Storms And Substorms ◽  
Substorm Onsets

Abstract. In order to investigate the causal relationship between magnetic storms and substorms, variations of the mid-latitude geomagnetic indices, ASY (asymmetric part) and SYM (symmetric part), at substorm onsets are examined. Substorm onsets are defined by three different phenomena; (1) a rapid increase in the mid-latitude asymmetric-disturbance indices, ASY-D and ASY-H, with a shape of so-called `mid-latitude positive bay\\'; (2) a sharp decrease in the AL index; (3) an onset of Pi2 geomagnetic pulsation. The positive bays are selected using eye inspection and a pattern-matching technique. The 1-min-resolution SYM-H index, which is essentially the same as the hourly Dst index except in terms of the time resolution, does not show any statistically significant development after the onset of substorms; it tends to decay after the onset rather than to develop. It is suggested by a simple model calculation that the decay of the magnetospheric tail current after substorm onset is responsible for the decay of the Dst field. The relation between the IMF southward turning and the development of the Dst field is re-examined. The results support the idea that the geomagnetic storms and substorms are independent processes; that is, the ring-current development is not the result of the frequent occurrence of substorms, but that of enhanced convection caused by the large southward IMF. A substorm is the process of energy dissipation in the magnetosphere, and its contribution to the storm-time ring-current formation seems to be negligible. The decay of the Dst field after a substorm onset is explained by a magnetospheric energy theorem.

scholarly journals Prediction of SYM-H index during large storms by NARX neural network from IMF and solar wind data

2010 ◽  
Vol 28 (2) ◽  
pp. 381-393 ◽  
Author(s):  
L. Cai ◽  
S. Y. Ma ◽  
Y. L. Zhou
Keyword(s):  
Neural Network ◽  
Solar Wind ◽  
Correlation Coefficient ◽  
Characteristic Time ◽  
Ring Current ◽  
Wind Data ◽  
Distinct Advantage ◽  
Elman Network ◽  
H Index ◽  
Narx Neural Network

Abstract. Similar to the Dst index, the SYM-H index may also serve as an indicator of magnetic storm intensity, but having distinct advantage of higher time-resolution. In this study the NARX neural network has been used for the first time to predict SYM-H index from solar wind (SW) and IMF parameters. In total 73 time intervals of great storm events with IMF/SW data available from ACE satellite during 1998 to 2006 are used to establish the ANN model. Out of them, 67 are used to train the network and the other 6 samples for test. Additionally, the NARX prediction model is also validated using IMF/SW data from WIND satellite for 7 great storms during 1995–1997 and 2005, as well as for the July 2000 Bastille day storm and November 2001 superstorm using Geotail and OMNI data at 1 AU, respectively. Five interplanetary parameters of IMF Bz, By and total B components along with proton density and velocity of solar wind are used as the original external inputs of the neural network to predict the SYM-H index about one hour ahead. For the 6 test storms registered by ACE including two super-storms of min. SYM-H<−200 nT, the correlation coefficient between observed and NARX network predicted SYM-H is 0.95 as a whole, even as high as 0.95 and 0.98 with average relative variance of 13.2% and 7.4%, respectively, for the two super-storms. The prediction for the 7 storms with WIND data is also satisfactory, showing averaged correlation coefficient about 0.91 and RMSE of 14.2 nT. The newly developed NARX model shows much better capability than Elman network for SYM-H prediction, which can partly be attributed to a key feedback to the input layer from the output neuron with a suitable length (about 120 min). This feedback means that nearly real information of the ring current status is effectively directed to take part in the prediction of SYM-H index by ANN. The proper history length of the output-feedback may mainly reflect on average the characteristic time of ring current decay which involves various decay mechanisms with ion lifetimes from tens of minutes to tens of hours. The Elman network makes feedback from hidden layer to input only one step, which is of 5 min for SYM-H index in this work and thus insufficient to catch the characteristic time length.

Non-uniform growth of the ring current belt

1969 ◽  
Vol 17 (4) ◽  
pp. 707-714 ◽  
Author(s):  
S.-I. Akasofu ◽  
C.-I. Meng
Keyword(s):  
Ring Current ◽  
Uniform Growth
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