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 timing of substorms associated with an interplanetary magnetic field sector boundary crossing.

1978 ◽  
Vol 30 (3) ◽  
pp. 197-198 ◽  
Author(s):  
T. R. SANDERSON ◽  
U. FAHLESON ◽  
A. GONFALONE ◽  
B. HOLBACK ◽  
R. LUNDIN ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Interplanetary Magnetic Field ◽  
Boundary Crossing ◽  
Sector Boundary

scholarly journals Effect of geomagnetic activity, solar wind and parameters of interplanetary magnetic field on regularities in intermittency of Pi2 geomagnetic pulsations

2015 ◽  
Vol 1 (3) ◽  
pp. 11-20 ◽  
Author(s):  
Надежда Куражковская ◽  
Nadezhda Kurazhkovskaya ◽  
Борис Клайн ◽  
Boris Klain
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Interplanetary Magnetic Field ◽  
Geomagnetic Activity ◽  
Dynamic Pressure ◽  
Cumulative Distribution ◽  
Qualitative Assessment ◽  
Geomagnetic Pulsations ◽  
Magnetospheric Substorms ◽  
Pi2 Pulsations

We present the results of investigation of the influence of geomagnetic activity, solar wind and parameters of the interplanetary magnetic field (IMF) on properties of the intermittency of midlatitude burst series of Pi2 geomagnetic pulsations observed during magnetospheric substorms on the nightside (substorm Pi2) and in the absence of these phenomena (nonsub-storm Pi2). We considered the index α as a main characteristic of intermittency of substorm and nonsubstorm Pi2 pulsations. The index α characterizes the slope of the cumulative distribution function of Pi2 burst amplitudes. The study indicated that the value and dynamics of the index α varies depending on the planetary geomagnetic activity, auroral activity and the intensity of magnetospheric ring currents. In addition, the forms of dependences of the index α on the density n, velocity V, dynamic pressure Pd of the solar wind and IMF Bx-component are different. The behavior of the index α depending on the module of B, By- and Bz-components is similar. We found some critical values of V, Pd, B, By- and Bz-components, after reaching of which the turbulence of the magnetotail plasma during substorm development is decreased. The revealed patterns of the intermittency of Pi2 pulsations can be used for qualitative assessment of turbulence level in the magnetotail plasma depending on changing interplanetary conditions.

scholarly journals Reconstruction of geomagnetic activity and near-Earth interplanetary conditions over the past 167 yr – Part 2: A new reconstruction of the interplanetary magnetic field

2013 ◽  
Vol 31 (11) ◽  
pp. 1979-1992 ◽  
Author(s):  
M. Lockwood ◽  
L. Barnard ◽  
H. Nevanlinna ◽  
M. J. Owens ◽  
R. G. Harrison ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Interplanetary Magnetic Field ◽  
Geomagnetic Activity ◽  
Flow Speed ◽  
Range Data ◽  
Solar Wind Flow ◽  
Annual Means ◽  
Solar Wind Parameters ◽  
The Imf

Abstract. We present a new reconstruction of the interplanetary magnetic field (IMF, B) for 1846–2012 with a full analysis of errors, based on the homogeneously constructed IDV(1d) composite of geomagnetic activity presented in Part 1 (Lockwood et al., 2013a). Analysis of the dependence of the commonly used geomagnetic indices on solar wind parameters is presented which helps explain why annual means of interdiurnal range data, such as the new composite, depend only on the IMF with only a very weak influence of the solar wind flow speed. The best results are obtained using a polynomial (rather than a linear) fit of the form B = χ · (IDV(1d) − β)α with best-fit coefficients χ = 3.469, β = 1.393 nT, and α = 0.420. The results are contrasted with the reconstruction of the IMF since 1835 by Svalgaard and Cliver (2010).

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 Diurnal and seasonal occurrence of polar patches

1996 ◽  
Vol 14 (5) ◽  
pp. 533-537 ◽  
Author(s):  
A. S. Rodger ◽  
A. C. Graham
Keyword(s):  
Magnetic Field ◽  
Seasonal Variation ◽  
Interplanetary Magnetic Field ◽  
Radar Data ◽  
Hf Radar ◽  
Polar Cap ◽  
Sunspot Maximum ◽  
Ionospheric Effects ◽  
Flux Transfer Events ◽  
Local Noon

Abstract. Analysis of the diurnal and seasonal variation of polar patches, as identified in two years of HF-radar data from Halley, Antarctica during a period near sunspot maximum, shows that there is a broad maximum in occurrence centred about magnetic noon, not local noon. There are minima in occurrence near midsummer and midwinter, with maxima in occurrence between equinox and winter. There are no significant correlations between the occurrence of polar patches and the corresponding hourly averages of the solar wind and IMF parameters, except that patches usually occur when the interplanetary magnetic field has a southward component. The results can be understood in terms of UT and seasonal differences in the plasma concentration being convected from the dayside ionosphere into the polar cap. In summer and winter the electron concentrations in the polar cap are high and low, respectively, but relatively unstructured. About equinox, a tongue of enhanced ionisation is convected into the polar cap; this tongue is then structured by the effects of the interplanetary magnetic field, but these Halley data cannot be used to separate the various competing mechanisms for patch formation. The observed diurnal and seasonal variation in the occurrence of polar patches are largely consistent with predictions of Sojka et al. (1994) when their results are translated into the southern hemisphere. However, the ionospheric effects of flux transfer events are still considered essential in their formation, a feature not yet included in the Sojka et al. model.

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)

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