scholarly journals Magnetic cloud field intensities and solar wind velocities

1998 ◽  
Vol 25 (7) ◽  
pp. 963-966 ◽  
Author(s):  
W. D. Gonzalez ◽  
A. L. Clúa de Gonzalez ◽  
A. Dal Lago ◽  
B. T. Tsurutani ◽  
J. K. Arballo ◽  
...  
Keyword(s):  
Solar Wind ◽  
Magnetic Cloud ◽  
Wind Velocities

scholarly journals Ionospheric total electron content responses to HILDCAA intervals

2020 ◽  
Vol 38 (1) ◽  
pp. 27-34
Author(s):  
Regia Pereira da Silva ◽  
Clezio Marcos Denardini ◽  
Manilo Soares Marques ◽  
Laysa Cristina Araujo Resende ◽  
Juliano Moro ◽  
...  
Keyword(s):  
Solar Wind ◽  
Total Electron Content ◽  
High Speed ◽  
Electron Content ◽  
Direct Relation ◽  
Total Electron ◽  
Ionospheric Total Electron Content ◽  
Long Duration ◽  
Wind Velocities ◽  
Hourly Distribution

Abstract. The High-Intensity Long-Duration and Continuous AE Activities (HILDCAA) intervals are capable of causing a global disturbance in the terrestrial ionosphere. However, the ionospheric storms' behavior due to these intervals is still not widely understood. In the current study, we seek to comprise the HILDCAA disturbance time effects in the total electron content (TEC) values with respect to the quiet days' pattern by analyzing local time and seasonal dependences, and the influences of the solar wind velocity on a sample of 10 intervals that occurred in the years 2015 and 2016. The main results showed that the hourly distribution of the disturbance TEC may vary substantially between one HILDCAA interval and another. An equinoctial anomaly was found since the equinoxes represent more ionospheric TEC responses than the solstices. Regarding the solar wind velocities, although HILDCAA intervals are associated with high-speed streams, this association does not present a direct relation to TEC disturbance magnitudes at low and equatorial latitudes.

scholarly journals Discontinuities and Alfvénic fluctuations in the solar wind

2013 ◽  
Vol 31 (5) ◽  
pp. 871-887 ◽  
Author(s):  
G. Paschmann ◽  
S. Haaland ◽  
B. Sonnerup ◽  
T. Knetter
Keyword(s):  
Solar Wind ◽  
Full Range ◽  
Flow Speed ◽  
Reduced Form ◽  
Angular Deviation ◽  
Cluster Data ◽  
Flow Speeds ◽  
Wind Velocities ◽  
Two Sides ◽  
Average Angle

Abstract. We examine the Alfvénicity of a set of 188 solar wind directional discontinuities (DDs) identified in the Cluster data from 2003 by Knetter (2005), with the objective of separating rotational discontinuities (RDs) from tangential ones (TDs). The DDs occurred over the full range of solar wind velocities and magnetic shear angles. By performing the Walén test in the de Hoffmann–Teller (HT) frame, we show that 77 of the 127 crossings for which a good HT frame was found had plasma flow speeds exceeding 80% of the Alfvén speed at an average angular deviation of 7.7°; 33 cases had speeds exceeding 90% of the Alfvén speed at an average angle of 6.4°. We show that the angular deviation between flow velocity (in the HT frame) and the Alfvén velocity can be obtained from a reduced form of the Walén correlation coefficient. The corresponding results from the Walén test expressed in terms of jumps in flow speed and corresponding jumps in Alfvén speed are similar: 66 of the same 127 cases had velocity jumps exceeding 80% with average angular deviation of 5.8°, and 22 exceeding 90% of the jump in Alfvén speed, with average angular deviation 6.2°. We conclude that a substantial fraction of the 127 events can be identified as RDs. We present further evidence for coupling across the DDs by showing that, for most of the 127 crossings, the HT frame velocities, evaluated separately on the two sides of the DD, are nearly the same – a result required for RDs but not for TDs. We also show that the degree of Alfvénicity is nearly the same for the DDs and fluctuations in which the DDs are embedded. Whatever process causes deviations from ideal Alfvénicity appears to operate equally for the DDs as for the surrounding fluctuations. Finally, our study has established a unique relation between the strahl electron pitch angle and the sign of the Walén slope, implying antisunward propagation in the plasma frame for all 127 cases.

scholarly journals Radial variation of solar wind electrons inside a magnetic cloud observed at 1 and 5 AU

2000 ◽  
Vol 105 (A12) ◽  
pp. 27269-27275 ◽  
Author(s):  
R. M. Skoug ◽  
W. C. Feldman ◽  
J. T. Gosling ◽  
D. J. McComas ◽  
D. B. Reisenfeld ◽  
...  
Keyword(s):  
Solar Wind ◽  
Magnetic Cloud ◽  
Radial Variation

ESTABLISHING THE ORIENTATION OF SHOCK WAVE PLANE OF SOLAR WIND MAGNETIC CLOUD FOR CONCLUSIONS ABOUT THE LEVEL OF AURORAL SUBSTORM ACTIVITY

2019 ◽  
Vol 17 (1) ◽  
pp. 195-202 ◽  
Author(s):  
N. A. Barkhatov ◽  
S. E. Revunov ◽  
M. V. Mukhina ◽  
M. L. Gruzdeva ◽  
O. T. Cherney ◽  
...  
Keyword(s):  
Shock Wave ◽  
Solar Wind ◽  
Magnetic Cloud ◽  
Auroral Substorm ◽  
Substorm Activity

scholarly journals Reflected solar wind ions and downward accelerated ionospheric ions during the January 1997 magnetic cloud event

1998 ◽  
Vol 25 (15) ◽  
pp. 2979-2982 ◽  
Author(s):  
D. L. Dempsey ◽  
J. L. Burch ◽  
M. M. Huddleston ◽  
C. J. Pollock ◽  
J. H. Waite ◽  
...  
Keyword(s):  
Solar Wind ◽  
Magnetic Cloud

The solar wind magnetic cloud of October 18–20, 1995: effect on ionosphere of the Russian Asian region

2001 ◽  
Vol 27 (8) ◽  
pp. 1381-1384 ◽  
Author(s):  
V.I. Kurkin ◽  
N.M. Polekh ◽  
O.M. Pirog ◽  
L.V. Chistyakova ◽  
G.A. Zherebtsov
Keyword(s):  
Solar Wind ◽  
Magnetic Cloud ◽  
Asian Region
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