scholarly journals Ionospheric response to the interplanetary magnetic field southward turning: Fast onset and slow reconfiguration

2002 ◽  
Vol 107 (A8) ◽  
pp. SIA 2-1-SIA 2-9 ◽  
Author(s):  
G. Lu ◽  
T. E. Holzer ◽  
D. Lummerzheim ◽  
J. M. Ruohoniemi ◽  
P. Stauning ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Interplanetary Magnetic Field ◽  
Ionospheric Response ◽  
Fast Onset

scholarly journals Dayside ionospheric response to changes in IMF polarity: optical and plasma-flow observations

2000 ◽  
Vol 18 (7) ◽  
pp. 782-788 ◽  
Author(s):  
S. E. Pryse ◽  
A. M. Smith ◽  
L. Kersley
Keyword(s):  
Magnetic Field ◽  
Interplanetary Magnetic Field ◽  
Plasma Flow ◽  
Line Emission ◽  
Line Of Sight ◽  
Magnetospheric Physics ◽  
Polar Cap ◽  
Ionospheric Response ◽  
Present Case Study

Abstract. The response of the dayside ionosphere to changes in polarity of the interplanetary magnetic field was observed by two independent techniques. The signatures were seen in the 630.0 nm red-line emission, measured by a meridian scanning photometer at Ny-Ålesund on Svalbard, and also in the line-of-sight plasma velocities monitored by the Finland CUTLASS SuperDARN radar. A time difference of some 6 to 8 min occurred between the responses of the two techniques, with the flows being first to respond. In the present case study, the longer delay in the optics suggests that ion precipitation controls the auroral emission.Key words: Ionosphere (ionosphere-magnetosphere interactions) · Magnetospheric physics (magnetosphere-ionosphere interactions; polar cap phenomena)

scholarly journals Interhemispheric observations of the ionospheric signature of tail reconnection during IMF-northward non-substorm intervals

2005 ◽  
Vol 23 (5) ◽  
pp. 1763-1770 ◽  
Author(s):  
A. Grocott ◽  
T. K. Yeoman ◽  
S. E. Milan ◽  
S. W. H. Cowley
Keyword(s):  
Magnetic Field ◽  
Interplanetary Magnetic Field ◽  
Field Data ◽  
Plasma Convection ◽  
Field Orientation ◽  
Magnetic Field Data ◽  
Ionospheric Response ◽  
Ionosphere Plasma ◽  
Dayside Magnetopause ◽  
Geosynchronous Satellites

Abstract. This paper presents the first interhemispheric radar observations interpreted as the ionospheric response to tail reconnection during IMF-northward non-substorm intervals. SuperDARN measurements of plasma convection in the nightside ionospheres of both hemispheres, taken on 21–22 February and 26–27 April 2000, show bursts of flow in the midnight sector which are understood to be characteristic of such phenomena. Upstream interplanetary magnetic field data confirm that the field orientation at the dayside magnetopause was northwards, but with a significant IMF By component (negative during the first interval, positive during the second), for many hours prior to the bursts being observed. During the By-negative interval the bursts were directed westwards in the Northern Hemisphere and eastwards in the Southern Hemisphere; during the By-positive interval their directions were reversed. These two asymmetries between the different orientations of IMF By and between the two hemispheres are key to our understanding of the magnetospheric phenomenon responsible for generating the bursts. They provide further evidence in support of the idea that the bursts are a result of reconnection in an asymmetric tail under the prolonged influence of IMF By. Concurrent data from ground magnetometers and geosynchronous satellites confirm that the bursts have no associated substorm characteristics, consistent with previous studies. Keywords. Ionosphere (Plasma convection; Ionospheremagnetosphere interactions) – Magnetospheric Physics (Magnetotail)

scholarly journals The mean solar magnetic field as an indicator of the interplanetary magnetic field

1996 ◽  
Vol 39 (4) ◽  
Author(s):  
J. Bremer
Keyword(s):  
Magnetic Field ◽  
Interplanetary Magnetic Field ◽  
Structure Data ◽  
Solar Magnetic Field ◽  
Private Communication ◽  
Sector Structure ◽  
Ionospheric Effect ◽  
Ionospheric Response ◽  
The Earth ◽  
The Mean

The Mean Solar Magnetic Field (MSMF) measured daily by ground based observations at the Standford Observatory shows similar structures like the Interplanetary Magnetic Field (IMF) near the Earth about 5 to 7 days later. The ionospheric effect in the mid-latitude F2-region due to such MSMF changes is most marked for strong MSMF changes from anti to pro sectors. The mean ionospheric response is very similar to the results obtained earlier with IMF sector structure data derived from Svalgaard (1976) and Wilcox (1982, private communication). Therefore, the MSMF data can successfully be used to predict the mean IMF sector structure and the mean ionospheric response 5 to 7 days in advance.

scholarly journals Influence of the interplanetary magnetic field on the variability of the mid-latitude F2-layer

1996 ◽  
Vol 39 (4) ◽  
Author(s):  
J. Bremer ◽  
J. Lastovicka ◽  
Y. Tulunay
Keyword(s):  
Magnetic Field ◽  
Interplanetary Magnetic Field ◽  
Geomagnetic Activity ◽  
Ionospheric Plasma ◽  
Satellite Observations ◽  
Sector Boundary ◽  
Night Time ◽  
Ionospheric Response ◽  
Ionospheric Effects ◽  
Boundary Crossings

The structure of the Interplanetary Magnetic Field (IMF) is responsible for an essential part of the variability of the ionospheric plasma as demonstrated by investigations of the influence of IMF sector boundary crossings as well as of ?Bz-changes (defined from satellite observations) to the maximal electron density of the F2-layer at different stations in mid-latitudes. It could be shown that negative Bz-values cause distinct negative ionospheric effects. Maximal effects were detected at high geomagnetic latitudes (ionospheric response decreases with decreasing latitude), high solar/geomagnetic activity, equinoxes and night-time conditions.

scholarly journals The ionospheric response to interplanetary magnetic field variations: Evidence for rapid global change and the role of preconditioning in the magnetosphere

2000 ◽  
Vol 105 (A10) ◽  
pp. 22955-22977 ◽  
Author(s):  
Masakazu Watanabe ◽  
Natsuo Sato ◽  
Raymond A. Greenwald ◽  
Michael Pinnock ◽  
Marc R. Hairston ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Global Change ◽  
Interplanetary Magnetic Field ◽  
Ionospheric Response ◽  
Magnetic Field Variations

Ionospheric response to changes in the interplanetary magnetic field observed by EISCAT and AMPTE–UKS

Nature ◽  
1985 ◽  
Vol 318 (6045) ◽  
pp. 451-452 ◽  
Author(s):  
H. Rishbeth ◽  
P. R. Smith ◽  
S. W. H. Cowley ◽  
D. M. Willis ◽  
A. P. van Eyken ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Interplanetary Magnetic Field ◽  
Ionospheric Response

H-Cmes and Ii-Type Radio Bursts Related Intense Geomagnetic Storms in Relation With Interplanetary Magnetic Field and Solar Wind Disturbances

2012 ◽  
Vol 2 (10) ◽  
pp. 1-3 ◽  
Author(s):  
Praveen Kumar Gupta ◽  
◽  
Puspraj Singh Puspraj Singh ◽  
Puspraj Singh Puspraj Singh ◽  
P. K. Chamadia P. K. Chamadia
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Interplanetary Magnetic Field ◽  
Geomagnetic Storms ◽  
Radio Bursts ◽  
Solar Wind Disturbances
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