scholarly journals Low-frequency (0.7-7.4 mHz) geomagnetic field fluctuations at high latitude: frequency dependence of the polarization pattern

2009 ◽  
Vol 44 (3) ◽  
Author(s):  
S. Lepidi ◽  
P. Francia ◽  
L. Cafarella
Keyword(s):  
Frequency Dependence ◽  
High Latitude ◽  
Geomagnetic Field ◽  
Low Frequency ◽  
Polarization Pattern ◽  
Field Fluctuations

Polarization pattern of low-frequency geomagnetic field fluctuations (0.8-3.6 mHz) at high and low latitude

1999 ◽  
Vol 104 (A1) ◽  
pp. 305-310 ◽  
Author(s):  
S. Lepidi ◽  
P. Francia ◽  
U. Villante ◽  
L. J. Lanzerotti ◽  
A. Meloni
Keyword(s):  
Geomagnetic Field ◽  
Low Frequency ◽  
Polarization Pattern ◽  
Low Latitude ◽  
Field Fluctuations

Determining the Polar Cusp Longitudinal Location from Pc5 Geomagnetic Field Measurements at a Pair of High Latitude Stations

2017 ◽  
Vol 13 (S335) ◽  
pp. 139-141
Author(s):  
Stefania Lepidi ◽  
Patrizia Francia ◽  
Lili Cafarella ◽  
Domenico Di Mauro ◽  
Martina Marzocchetti
Keyword(s):  
Magnetic Field ◽  
Satellite Data ◽  
High Latitude ◽  
Geomagnetic Field ◽  
Geomagnetic Latitude ◽  
Low Frequency ◽  
Field Measurements ◽  
Polar Cap ◽  
Polar Cusp ◽  
Local Noon

AbstractWe use low frequency geomagnetic field measurements at two Antarctic stations to statistically investigate the longitudinal location of the polar cusp. The two stations are both located in the polar cap at a geomagnetic latitude close to the cusp latitude; they are separated by one hour in magnetic local time. At each station the Pc5 power maximizes when the station approaches the cusp, i.e. around magnetic local noon. The comparison between the Pc5 power at the two stations allows to determine the longitudinal location of the cusp. Our analysis is conducted considering separately different orientation of the interplanetary magnetic field. The results, which indicate longitudinal shifts of the polar cusp depending on the selected conditions, are discussed in relation to previous studies of the polar cusp location based on polar magnetospheric satellite data.

scholarly journals Low frequency geomagnetic field fluctuations at low latitude during the passage of a higher pressure solar wind region

1997 ◽  
Vol 15 (6) ◽  
pp. 656-661
Author(s):  
U. Villante ◽  
P. Francia
Keyword(s):  
Solar Wind ◽  
Geomagnetic Field ◽  
Low Frequency ◽  
Frequency Range ◽  
Low Latitude ◽  
Wind Region ◽  
Spectral Peaks ◽  
Field Fluctuations ◽  
Term Analysis

Abstract. The passage of a higher pressure solar wind region at the Earth's orbit marked the onset of low latitude (L=1.6) fluctuations in the frequency range (0.8–5.5 mHz) for both the horizontal geomagnetic field components. Spectral peaks mostly occur at the same frequencies as the spectral enhancements which appeared in the long term analysis of experimental measurements from the same station and were tentatively interpreted in terms of ground signatures of global magnetospheric modes. A comparison with simultaneous observations discussed by previous investigations allows us to conclude that the same set of frequencies is enhanced in a wide portion of the Earth's magnetosphere.

Low-frequency (1.7–6.7 mHz) geomagnetic-field fluctuations at high southern latitudes

1996 ◽  
Vol 19 (4) ◽  
pp. 517-525 ◽  
Author(s):  
P. Ballatore ◽  
S. Lepidi ◽  
L. Cafarella ◽  
U. Villante ◽  
A. Meloni ◽  
...  
Keyword(s):  
Geomagnetic Field ◽  
Low Frequency ◽  
Field Fluctuations

scholarly journals ULF fluctuations of the geomagnetic field and ionospheric sounding measurements at low latitudes during the first CAWSES campaign

2006 ◽  
Vol 24 (5) ◽  
pp. 1455-1468 ◽  
Author(s):  
U. Villante ◽  
M. Vellante ◽  
P. Francia ◽  
M. De Lauretis ◽  
A. Meloni ◽  
...  
Keyword(s):  
Solar Wind ◽  
Geomagnetic Field ◽  
Mass Density ◽  
Solar Wind Speed ◽  
Low Frequency ◽  
Ionospheric Currents ◽  
Ground Field ◽  
Low Latitudes ◽  
Field Fluctuations ◽  
Pulsation Activity

Abstract. We present an analysis of ULF geomagnetic field fluctuations at low latitudes during the first CAWSES campaign (29 March-3 April 2004). During the whole campaign, mainly in the prenoon sector, a moderate Pc3-4 pulsation activity is observed, clearly related to interplanetary upstream waves. On 3 April, in correspondence to the Earth's arrival of a coronal mass ejection, two SIs are observed whose waveforms are indicative of a contribution of the high-latitude ionospheric currents to the low-latitude ground field. During the following geomagnetic storm, low frequency (Pc5) waves are observed at discrete frequencies. Their correspondence with the same frequencies detected in the radial components of the interplanetary magnetic field and solar wind speed suggests that Alfvénic solar wind fluctuations may act as direct drivers of magnetospheric fluctuations. A cross-phase analysis, using different pairs of stations, is also presented for identifying field line resonant frequencies and monitoring changes in plasmaspheric mass density. Lastly, an analysis of ionospheric vertical soundings, measured at the Rome ionosonde station (41.8° N, 12.5° E), and vertical TEC measurements deduced from GPS signals within an European network shows the relation between the ULF resonances in the inner magnetosphere and thermal plasma density variations during geomagnetically quiet conditions, in contrast to various storm phases at the end of the CAWSES campaign.

Scaling Features of High‐Latitude Geomagnetic Field Fluctuations at Swarm Altitude: Impact of IMF Orientation

2017 ◽  
Vol 122 (10) ◽  
pp. 10,548-10,562 ◽  
Author(s):  
Paola De Michelis ◽  
Giuseppe Consolini ◽  
Roberta Tozzi ◽  
Maria Federica Marcucci
Keyword(s):  
High Latitude ◽  
Geomagnetic Field ◽  
Field Fluctuations ◽  
Scaling Features

scholarly journals Observations of high-latitude geomagnetic field fluctuations during St. Patrick’s Day storm: Swarm and SuperDARN measurements

2016 ◽  
Vol 68 (1) ◽  
Author(s):  
Paola De Michelis ◽  
Giuseppe Consolini ◽  
Roberta Tozzi ◽  
Maria Federica Marcucci
Keyword(s):  
High Latitude ◽  
Geomagnetic Field ◽  
Field Fluctuations

scholarly journals Influence of high-latitude geomagnetic pulsations on recordings of broadband force-balanced seismic sensors

2012 ◽  
Vol 1 (2) ◽  
pp. 85-101 ◽  
Author(s):  
E. Kozlovskaya ◽  
A. Kozlovsky
Keyword(s):  
Magnetic Field ◽  
Geomagnetic Field ◽  
Geomagnetic Latitude ◽  
Low Frequency ◽  
Auroral Oval ◽  
Polar Regions ◽  
Geomagnetic Pulsations ◽  
Seismic Sensors ◽  
Magnetic Poles ◽  
Magnetic Disturbances

Abstract. Seismic broadband sensors with electromagnetic feedback are sensitive to variations of surrounding magnetic field, including variations of geomagnetic field. Usually, the influence of the geomagnetic field on recordings of such seismometers is ignored. It might be justified for seismic observations at middle and low latitudes. The problem is of high importance, however, for observations in Polar Regions (above 60° geomagnetic latitude), where magnitudes of natural magnetic disturbances may be two or even three orders larger. In our study we investigate the effect of ultra-low frequency (ULF) magnetic disturbances, known as geomagnetic pulsations, on the STS-2 seismic broadband sensors. The pulsations have their sources and, respectively, maximal amplitudes in the region of the auroral ovals, which surround the magnetic poles in both hemispheres at geomagnetic latitude (GMLAT) between 60° and 80°. To investigate sensitivity of the STS-2 seismometer to geomagnetic pulsations, we compared the recordings of permanent seismic stations in northern Finland to the data of the magnetometers of the IMAGE network located in the same area. Our results show that temporary variations of magnetic field with periods of 40–150 s corresponding to regular Pc4 and irregular Pi2 pulsations are seen very well in recordings of the STS-2 seismometers. Therefore, these pulsations may create a serious problem for interpretation of seismic observations in the vicinity of the auroral oval. Moreover, the shape of Pi2 magnetic disturbances and their periods resemble the waveforms of glacial seismic events reported originally by Ekström (2003). The problem may be treated, however, if combined analysis of recordings of co-located seismic and magnetic instruments is used.

Sign in / Sign up

Export Citation Format

Share Document