Wavelet analysis of the magnetotail response to solar wind fluctuations during HILDCCA events

Abstract. In this work a study of the effects of the High-Intensity Long-Duration Continuous AE activity events (HILDCAAs) in the magnetotail was conducted. The aim of this study was to search the main frequencies during HILDCAAs in the Bx component of the geomagnetic field, as well as at the main frequencies which the magnetotail responds to the solar wind during these events. In order to conduct this analysis the wavelet transform was employed in 9 HILDCAA events that occurred after the Cluster mission (2000) and coincided with the Cluster crossing through the tail of the magnetosphere from 2003 to 2007. Altogether, 25 most energetic periods was observed, which 76 % are ≤ 4 hours. The cross wavelet analysis technique was also used for the development of this study. It was applied to data of the Bz-IMF component and the Bx geomagnetic component, searching to obtain the periods in that had the highest correlation between these two series. To obtain these periods is important to identify frequencies on which the coupling of energy is stronger, as well the modulation of the magnetotail by the solar wind during HILDCAA events. The majority of correlation periods between the Bz (IMF) and Bx component of the geomagnetic field observed also were ≤ 4 hours, with 62.9 % of the periods. Thus the magnetotail responds stronger to IMF fluctuations during HILDCCAS at 2–4 hours scales, which are typical substorm periods.

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Wavelet analysis of the magnetotail response to solar wind fluctuations during HILDCAA events

Annales Geophysicae ◽

10.5194/angeo-37-919-2019 ◽

2019 ◽

Vol 37 (5) ◽

pp. 919-929

Author(s):

Adriane Marques de Souza Franco ◽

Ezequiel Echer ◽

Mauricio José Alves Bolzan

Keyword(s):

Solar Wind ◽

Wavelet Transform ◽

Wavelet Analysis ◽

Geomagnetic Field ◽

Field Component ◽

Long Duration ◽

Analysis Technique ◽

Spacecraft Mission ◽

Cross Wavelet Analysis ◽

Cross Wavelet

Abstract. In this work a study of the effects of the high-intensity long-duration continuous AE activity (HILDCAAs) events in the magnetotail was conducted. The aim of this study was to search the main frequencies during HILDCAAs in the Bx component of the geomagnetic field in the magnetotail, as well as the main frequencies, at which the magnetotail responds to the solar wind during these events. In order to conduct this analysis the wavelet transform was employed during nine HILDCAA events that coincided with Cluster spacecraft mission crossing through the tail of the magnetosphere from 2003 to 2007. The most energetic periods for each event were identified. It was found that 76 % of them have periods ≤4 h. With the aim to search the periods that have the highest correlation between the IMF Bz (OMNI) component and the Cluster Bx geomagnetic field component, the cross wavelet analysis technique was also used in this study. The majority of correlation periods between the Bz (IMF) and Bx component of the geomagnetic field observed also were ≤4 h, with 62.9 % of the periods. Thus the magnetotail responds stronger to IMF fluctuations during HILDCCAS at 2–4 h scales, which are typical substorm periods. The results obtained in this work show that these scales are the ones on which the coupling of energy is stronger, as well as the modulation of the magnetotail by the solar wind during HILDCAA events.

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A Study of the Time Lags of the Indian Ocean Dipole and Rainfall Over Thailand by Using the Cross Wavelet Analysis

Arabian Journal for Science and Engineering ◽

10.1007/s13369-014-1480-1 ◽

2014 ◽

Vol 40 (1) ◽

pp. 215-225 ◽

Cited By ~ 4

Author(s):

Kosum Chansaengkrachang ◽

Anirut Luadsong ◽

Nitima Aschariyaphotha

Keyword(s):

Indian Ocean ◽

Wavelet Analysis ◽

Indian Ocean Dipole ◽

Time Lags ◽

The Indian Ocean ◽

The Cross ◽

Cross Wavelet Analysis ◽

Cross Wavelet

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MULTIFRACTAL CROSS WAVELET ANALYSIS

Fractals ◽

10.1142/s0218348x17500542 ◽

2017 ◽

Vol 25 (06) ◽

pp. 1750054 ◽

Cited By ~ 32

Author(s):

ZHI-QIANG JIANG ◽

XING-LU GAO ◽

WEI-XING ZHOU ◽

H. EUGENE STANLEY

Keyword(s):

Wavelet Analysis ◽

Long Range ◽

Cross Correlation ◽

Multifractal Spectrum ◽

Theoretical Formula ◽

Cross Correlations ◽

The Cross ◽

Cross Wavelet Analysis ◽

Multifractal Behavior ◽

Cross Wavelet

Complex systems are composed of mutually interacting components and the output values of these components usually exhibit long-range cross-correlations. Using wavelet analysis, we propose a method of characterizing the joint multifractal nature of these long-range cross correlations, a method we call multifractal cross wavelet analysis (MFXWT). We assess the performance of the MFXWT method by performing extensive numerical experiments on the dual binomial measures with multifractal cross correlations and the bivariate fractional Brownian motions (bFBMs) with monofractal cross correlations. For binomial multifractal measures, we find the empirical joint multifractality of MFXWT to be in approximate agreement with the theoretical formula. For bFBMs, MFXWT may provide spurious multifractality because of the wide spanning range of the multifractal spectrum. We also apply the MFXWT method to stock market indices, and in pairs of index returns and volatilities we find an intriguing joint multifractal behavior. The tests on surrogate series also reveal that the cross correlation behavior, particularly the cross correlation with zero lag, is the main origin of cross multifractality.

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Polar Cap Potential and Merging Electric Field during High Intensity Long Duration Continuous Auroral Activity

Journal of Nepal Physical Society ◽

10.3126/jnphyssoc.v3i1.14437 ◽

2016 ◽

Vol 3 (1) ◽

pp. 6 ◽

Cited By ~ 6

Author(s):

Binod Adhikari ◽

Narayan P. Chapagain

Keyword(s):

Solar Wind ◽

Wavelet Transform ◽

Electric Field ◽

High Intensity ◽

Cross Correlation ◽

Auroral Electrojet ◽

Polar Cap ◽

Auroral Activity ◽

Long Duration ◽

Solar Wind Parameters

<p>The polar cap potential (PCV) has long been considered as a key parameter for describing the state of the magnetosphere/ionosphere system. The relationship between the solar wind parameters and the PCV is important to understand the coupling process between solar wind-magnetosphere-ionosphere. In this work, we have estimated PCV and merging electric field (Em) during two different high intensity long duration continuous auroral activity (HILDCAA) events. For each event, we examine the solar wind parameters, magnitude of interplanetary magnetic field (IMF), interplanetary electric field (IEF), PCV, Em and geomagnetic indices (i.e., SYM-H, geomagnetic auroral electrojet (AE) index, polar cap index (PCI) and auroral electrojet index lower (AL), respectively). We also study the role of PCI and AL indices to monitor polar cap (PC) activity during HILDCAAs. In order to verify their role, we use wavelet transform and cross-correlation techniques. For the three events studied here, the results obtained from continuous wavelet transform (CWT) and discrete wavelet transform (DWT) are different, however the effect of HILDCAA can be easily identified. We also observe the cross-correlation of PCI and PCV with AL, SYM-H, Bz component of the IMF and Ey component of the IEF individually. Both PCI and PCV show very good correlation with AL and SYM-H indices during the events. Observing these results, it can be suggested that PCI and AL indices play a significant role to monitor geomagnetic activity generated by geoeffective solar wind parameters.</p><p>Journal of Nepal Physical Society Vol.3(1) 2015: 6-17</p>

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The Interconnection between the Periodicities of Solar Wind Parameters Based on the Interplanetary Magnetic Field Polarity (1967–2018): A Cross Wavelet Analysis

Solar Physics ◽

10.1007/s11207-020-01692-2 ◽

2020 ◽

Vol 295 (9) ◽

Author(s):

M. A. El-Borie ◽

A. M. El-Taher ◽

A. A. Thabet ◽

A. A. Bishara

Keyword(s):

Magnetic Field ◽

Solar Wind ◽

Wavelet Analysis ◽

Interplanetary Magnetic Field ◽

Field Polarity ◽

Cross Wavelet Analysis ◽

Solar Wind Parameters ◽

Cross Wavelet

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ON THE CROSS WAVELET ANALYSIS OF DUFFING OSCILLATOR

Journal of Sound and Vibration ◽

10.1006/jsvi.1999.2420 ◽

1999 ◽

Vol 228 (1) ◽

pp. 199-210 ◽

Cited By ~ 17

Author(s):

A. KYPRIANOU ◽

W.J. STASZEWSKI

Keyword(s):

Wavelet Analysis ◽

Duffing Oscillator ◽

The Cross ◽

Cross Wavelet Analysis ◽

Cross Wavelet

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Wavelet analysis on transient behaviour of tidal amplitude fluctuations observed by meteor radar in the lower thermosphere above Bulgaria

Annales Geophysicae ◽

10.1007/s00585-000-0316-3 ◽

2000 ◽

Vol 18 (3) ◽

pp. 316-331 ◽

Cited By ~ 43

Author(s):

D. Pancheva ◽

P. Mukhtarov

Keyword(s):

Wavelet Transform ◽

Wavelet Analysis ◽

Morlet Wavelet ◽

Neutral Wind ◽

Bispectral Analysis ◽

Time Intervals ◽

Cross Wavelet Analysis ◽

Morlet Wavelet Transform ◽

Cross Wavelet ◽

Mlt Region

Abstract. On the basis of bispectral analysis applied to the hourly data set of neutral wind measured by meteor radar in the MLT region above Bulgaria it was demonstrated that nonlinear processes are frequently and regularly acting in the mesopause region. They contribute significantly to the short-term tidal variability and are apparently responsible for the observed complicated behavior of the tidal characteristics. A Morlet wavelet transform is proposed as a technique for studying nonstationary signals. By simulated data it was revealed that the Morlet wavelet transform is especially convenient for analyzing signals with: (1) a wide range of dominant frequencies which are localized in different time intervals; (2) amplitude and frequency modulated spectral components, and (3) singular, wave-like events, observed in the neutral wind of the MLT region and connected mainly with large-scale disturbances propagated from below. By applying a Morlet wavelet transform to the hourly values of the amplitudes of diurnal and semidiurnal tides the basic oscillations with periods of planetary waves (1.5-20 days), as well as their development in time, are obtained. A cross-wavelet analysis is used to clarify the relation between the tidal and mean neutral wind variability. The results of bispectral analysis indicate which planetary waves participated in the nonlinear coupling with the atmospheric tides, while the results of cross-wavelet analysis outline their time intervals if these interactions are local.Key words: Meteorology and atmospheric dynamics (middle atmosphere dynamics; waves and tides) - Radio science (nonlinear phenomena)

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