Solar Wind Conditions Research Articles

Can Solar Wind Decompressive Discontinuities Suppress Magnetospheric Electromagnetic Ion Cyclotron Waves Associated With Fresh Proton Injections?

AbstractElectromagnetic ion cyclotron (EMIC) waves play an important role in the energy transfer among particles of different energies and species in the magnetosphere, whose drivers have been commonly recognized as solar wind compressions and storm/substorm proton injections. However, how the solar wind decompressions related to frequently occurring discontinuities compete with the proton injections in the evolution of EMIC waves has been rarely investigated. Here we present a complete end‐to‐end observation by Wind, THEMIS, and Van Allen Probes missions during the main phase of the 23 February 2014 storm of a succession of solar wind rotational discontinuities decompressing the magnetosphere within 200 s, adiabatically decelerating the freshly injected >10 keV protons, and thus suppressing the EMIC waves in the inner magnetosphere. Our results highlight the importance of solar wind conditions for the evolution of inner magnetospheric EMIC waves from a new perspective.

Inner Magnetospheric ULF Waves: The Occurrence and Distribution of Broadband and Discrete Wave Activity

AbstractUltralow frequency (ULF) waves are electromagnetic pulsations observed throughout the magnetosphere driven by processes both external and internal to the magnetosphere. Within the magnetosphere, discrete and broadband ULF wave activity can couple to the local plasma via coherent or stochastic wave‐particle interactions. These wave‐particle interactions can lead to dynamic changes in local plasma including rapid acceleration and transport of radiation belt electrons. Using observations from GOES‐15 and the Automated Flare Inference of Oscillations algorithm we investigate the distribution and occurrence of broadband and discrete ULF waves to help understand the relative importance of coherent and stochastic wave‐particle interactions. We find that intervals of discrete ULF waves are more commonly identified during slow and low‐density solar wind and when Bz is near zero. Broadband waves are more commonly identified during periods of active solar wind, including periods of high solar wind speeds and large density perturbations, and large negative Bz. We also find that under all solar wind conditions the number of intervals of broadband ULF wave power exceeds that of discrete wave power; for example, ULF wave activity is more likely to be broadband. These results suggest that radial diffusion due to incoherent broadband waves is an important driver of wave‐particle interactions, especially during active solar wind conditions. However, the presence of discrete waves during both active and quiet solar wind conditions suggests that these waves and the corresponding wave‐particle interactions cannot be ignored, especially since discrete wave‐particle interactions tend to be more efficient than radial diffusion.

Solar Wind Conditions During the First 42 Months of Magnetospheric Multiscale Mission

AbstractKnowledge of the solar wind conditions is important to study the magnetosphere by missions, such as Magnetospheric Multiscale (MMS) and the Time History of Events and Macroscale Interactions during Substorms (THEMIS). We examine the magnetic field and plasma data obtained by three solar wind monitors, ACE, Wind, and DSCOVR to check the consistency and survey the statistical properties of the solar wind during 2015–2018, the first 42 months of the MMS mission. In the consistency study, we exclude the effect of limited cross‐flow correlation lengths of solar wind properties and confirmed that the magnetic field measurements from different spacecraft are consistent on average. We also suggest that ACE and Wind measurements are best used for the temperature and velocity data; while for density measurements, DSCOVR and Wind data should be used when available. In the statistical study, by comparing the recent data with that in 2008, we find that the magnetic field conditions are generally the same but the plasma properties have changed. On average, the MMS measurements are obtained when Earth is in a lower dynamic pressure and smaller plasma beta solar wind than that of previous studies. These 2015–2018 conditions favor the occurrence of magnetic reconnection, which assumes a great role in driving the dynamics of the magnetosphere.

Formation and Topology of Foreshock Bubbles

AbstractWe use global and local hybrid (kinetic ions and fluid electrons) simulations to investigate the conditions under which foreshock bubbles (FBs) form and how their topology changes with solar wind conditions. FBs form as a result of the interaction between solar wind discontinuities and backstreaming ion beams in the foreshock. They consist of an outer shock and its associated sheath plasma and a low density high temperature core with low magnetic field strength. The structure of FBs is determined by the angle between the interplanetary magnetic field and the normal to the solar wind discontinuity. We show that interaction of rotational discontinuities with the foreshock during small angles between the interplanetary magnetic field and discontinuity normal results in the formation of a nearly spherical bubble with a radius that scales with the width of the foreshock. As this angle increases, FBs become more elongated and eventually become nearly planar structures with dimensions that scale with the length of the foreshock. Despite this transformation, the signatures of FBs in spacecraft time series data remain the same in agreement with the observations. Global simulation results show that FBs form when the solar wind flow speed corresponds to high or intermediate Alfvén Mach numbers (approximately >7 MA). In general, this is tied to the relative speed between the solar wind and ion beams and drop in density of the backstreaming ions.

How whistler mode hiss waves and the plasmasphere drive the quiet decay of radiation belts electrons following a geomagnetic storm

We show how an extended period of quiet solar wind conditions contributes to a quiet state of the plasmasphere that expands up to L ∼ 5.5, which creates the perfect conditions for wave-particle interactions between the radiation belt electrons and whistler-mode hiss waves. The correlation between the hiss waves and the plasma density is direct with hiss wave power increasing with plasma density, while it was generally assumed that these quantities can be specified independently. Whistler-mode hiss waves pitch angle diffuse and ultimately scatter freshly injected electrons into the atmosphere until the slot region is formed between the inner and outer belt and the outer belt is drastically reduced. In this study, we use and combine Van Allen Probes observations and Fokker-Planck numerical simulations. The Fokker-Planck model uses consistent event-driven pitch angle diffusion coefficients from whistler-mode hiss waves. Observations and simulations allow us to reach a global understanding of the variations in the trapped electron population with time, space, energy, and pitch angle that is based on the existing theory of quasi-linear wave-particle interactions. We show, for instance, the outer belt is pitch-angle homogeneous, which is explained by the event-driven diffusion coefficients that are roughly constant for equatorial pitch angle α 0∼<60°, E>100 keV, 3.5<L<Lpp∼6. The impact of this work is to bring an improved understanding of the belt evolution based on the integration of high quality and highly temporally and spatially resolved measurements that are integrated in modern computations. We also propose the event-driven method as an accurate method (within ×2) to predict the electron flux decay after storms.

EMIC Waves in the Earth's Inner Magnetosphere as a Function of Solar Wind Structures During Solar Maximum

AbstractHere we analyze the statistics of electromagnetic ion cyclotron (EMIC) waves observed in the Earth's inner magnetosphere during coronal mass ejection (CME), high‐speed stream (HSS), and quiet solar wind (QSW) conditions in the upstream solar wind (SW). For our analysis we use the EMIC wave observations by the two Van Allen Probes during their first magnetic local time (MLT) revolution. The major results of our analysis are as follows: (1) Criteria to identify the HSS, CME, and QSW conditions in the SW are formulated. (2) 54%, 36%, and 10% of EMIC wave events are observed during CME, HSS, and QSW, respectively. (3) 12% of events are closely associated with the fast growth of magnetospheric compression, among which 76%, 24%, and 0% are observed during CME, HSS, and QSW, respectively. (4) A majority of the QSW, HSS‐driven, and CME‐driven events is observed in the 9–12, 12–24, and 8–24 hr MLT sectors, respectively. (5) CME‐driven events are distributed along all L shells, whereas the majority of the HSS‐driven and QSW events are confined to L &gt; 3.5. (6) The fractions of events during CME and HSS have a maximum in the near‐equatorial region, whereas the fractions of the QSW events have a minimum there. (7) Independent of the SW driver, no strong events are observed below the local O+ gyrofrequency, whereas 65–70% and 30–35% of events are observed between the O+ and He+ gyrofrequencies and above the He+ gyrofrequency, respectively.

A Deep Learning‐Based Approach for Modeling the Dynamics of AMPERE Birkeland Currents

AbstractThe existence of Birkeland magnetic field‐aligned current (FAC) system was proposed more than a century ago, and it has been of immense interest for investigating the nature of solar wind‐magnetosphere‐ionosphere coupling ever since. In this paper, we present the first application of deep learning architecture for modeling the Birkeland currents using data from the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE). The model uses a 1‐hr time history of several different parameters such as interplanetary magnetic field (IMF), solar wind, and geomagnetic and solar indices as inputs to determine the global distribution of Birkeland currents in the Northern Hemisphere. We present a comparison between our model and bin‐averaged statistical patterns under steady IMF conditions and also when the IMF is variable. Our deep learning model shows good agreement with the bin‐averaged patterns, capturing several prominent large‐scale features such as the Regions 1 and 2 FACs, the NBZ current system, and the cusp currents along with their seasonal variations. However, when IMF and solar wind conditions are not stable, our model provides a more accurate view of the time‐dependent evolution of Birkeland currents. The reconfiguration of the FACs following an abrupt change in IMF orientation can be traced in its details. The magnitude of FACs is found to evolve with e‐folding times that vary with season and MLT. When IMF Bz turns southward after a prolonged northward orientation, NBZ currents decay exponentially with an e‐folding time of ∼25 min, whereas Region 1 currents grow with an e‐folding time of 6–20 min depending on the MLT.

Why Are There so Few Reports of High‐Energy Electron Drift Resonances? Role of Radial Phase Space Density Gradients

AbstractModels of monochromatic Pc5 (2–7 mHz) ultralow frequency (ULF) wave interactions with high energy (greater than ∼1 MeV) electrons predict drift resonant interactions that can cause rapid radial transport and acceleration. There are few reports of electron drift resonance at energies greater than ∼1 MeV, in contrast to lower energies; moreover, all previous reports occur in the aftermath of interplanetary shocks. These two facts are difficult to reconcile with theory and numerical simulations predicting that greater than ∼1 MeV drift resonances should occur more often and in a wider variety of driving conditions. In this study, we show that a combination of observational sampling biases and nominal radial phase space density gradients is one explanation for this discrepancy between theory and observations. In particular, we examine electron dynamics in two case studies with very similar satellite coverage, solar wind conditions, and Pc5 wave properties, yet with different radial phase space density profiles. Using global wave and particle observations, we show that the events have vastly different particle responses despite having similar wave properties. Placing these results in context with past studies, we further show that nominal radial PSD gradients near geostationary orbit can mask the expected drift resonance particle response and explain (1) the small number of past greater than ∼1 MeV drift resonance reports and (2) the restriction of these reports to interplanetary shock events. We argue that future observational studies characterizing radial transport via drift resonance should examine global particle dynamics, including observations of the radial phase space density profile.

Interhemispheric Conjugacy of Concurrent Onset and Poleward Traveling Geomagnetic Responses for Throat Aurora Observed Under Quiet Solar Wind Conditions

AbstractThroat auroras frequently observed near local noon have been confirmed to correspond to magnetopause indentations, but the generation mechanisms for these indentations and the detailed properties of throat aurora are both not fully understood. Using all‐sky camera and magnetometer observations, we reported some new observational features of throat aurora as follows. (1) Throat auroras can occur under stable solar wind conditions and cause clear geomagnetic responses. (2) These geomagnetic responses can be simultaneously observed at conjugate geomagnetic meridian chains in the Northern and Southern Hemispheres. (3) The initial geomagnetic responses of throat aurora show concurrent onsets that were observed at all stations along the meridians. (4) Immediately after the concurrent onsets, poleward moving signatures and micropositive bays were observed in the X components at higher‐ and lower‐latitude stations, respectively. We argue that these observations provide evidence for throat aurora being generated by low‐latitude magnetopause reconnection. We suggest that the concurrent onsets reflect the instantaneous responses of the reconnection signal arriving at the ionosphere, the followed poleward moving signatures reflect the antisunward dragging of the footprint of newly opened field lines, and the micropositive bays may result from a pair of field‐aligned currents generated during the reconnection. This study may shed new light on the geomagnetic transients observed at cusp latitude near magnetic local noon.

Evolution of the Earth’s Magnetosheath Turbulence: A Statistical Study Based on MMS Observations

Abstract Composed of shocked solar wind, the Earth’s magnetosheath serves as a natural laboratory to study the transition of turbulence from low Alfvén Mach number, M A, to high M A. The simultaneous observations of magnetic field and plasma moments with unprecedented high temporal resolution provided by NASA’s Magnetospheric Multiscale Mission (MMS) enable us to study the magnetosheath turbulence at both magnetohydrodynamics (MHD) and sub-ion scales. Based on 1841 burst-mode segments of MMS-1 from 2015 September to 2019 June, comprehensive patterns of the spatial evolution of magnetosheath turbulence are obtained: (1) from the subsolar region to the flanks, M A increases from &lt;1 to &gt;5. At MHD scales, the spectral indices of the magnetic-field and velocity spectra present a positive and negative correlation with M A. However, no obvious correlations between the spectral indices and M A are found at sub-ion scales. (2) From the bow shock to the magnetopause, the turbulent sonic Mach number, , generally decreases from &gt;0.4 to &lt;0.1. All spectra steepen at MHD scales and flatten at sub-ion scales, representing positive/negative correlations with M turb. The break frequency increases by 0.1 Hz when approaching the magnetopause for the magnetic-field and velocity spectra, while it remains at 0.3 Hz for the density spectra. (3) In spite of minor differences, similar results are found for the quasi-parallel and quasi-perpendicular magnetosheath. In addition, such spatial evolution of magnetosheath turbulence is found to be independent of the upstream solar wind conditions, e.g., the averaged Z-component of the interplanetary magnetic field and solar wind speed.

On the Regional Variability of dB/dt and Its Significance to GIC

AbstractFaraday's law of induction is responsible for setting up a geoelectric field due to the variations in the geomagnetic field caused by ionospheric currents. This drives geomagnetically induced currents (GICs) which flow in large ground‐based technological infrastructure such as high‐voltage power lines. The geoelectric field is often a localized phenomenon exhibiting significant variations over spatial scales of only hundreds of kilometers. This is due to the complex spatiotemporal behavior of electrical currents flowing in the ionosphere and/or large gradients in the ground conductivity due to highly structured local geological properties. Over some regions, and during large storms, both of these effects become significant. In this study, we quantify the regional variability of dB/dt using closely placed IMAGE stations in northern Fennoscandia. The dependency between regional variability, solar wind conditions, and geomagnetic indices are also investigated. Finally, we assess the significance of spatial geomagnetic variations to modeling GICs across a transmission line. Key results from this study are as follows: (1) Regional geomagnetic disturbances are important in modeling GIC during strong storms; (2) dB/dt can vary by several times up to a factor of three compared to the spatial average; (3) dB/dt and its regional variation is coupled to the energy deposited into the magnetosphere; and (4) regional variability can be more accurately captured and predicted from a local index as opposed to a global one. These results demonstrate the need for denser magnetometer networks at high latitudes where transmission lines extending hundreds of kilometers are present.

Statistical Study of Magnetosheath Jet‐Driven Bow Waves

AbstractWhen a magnetosheath jet (localized dynamic pressure enhancements) compresses ambient magnetosheath at a (relative) speed faster than the local magnetosonic speed, a bow wave or shock can form ahead of the jet. Such bow waves or shocks were recently observed to accelerate particles, thus contributing to magnetosheath heating and particle acceleration in the extended environment of Earth's bow shock. To further understand the characteristics of jet‐driven bow waves, we perform a statistical study to examine which solar wind conditions favor their formation and whether it is common for them to accelerate particles. We identified 364 out of 2,859 (~13%) magnetosheath jets to have a bow wave or shock ahead of them with Mach number typically larger than 1.1. We show that large solar wind plasma beta, weak interplanetary magnetic field (IMF) strength, large solar wind Alfvén Mach number, and strong solar wind dynamic pressure present favorable conditions for their formation. We also show that magnetosheath jets with bow waves or shocks are more frequently associated with higher maximum ion and electron energies than those without them, confirming that it is common for these structures to accelerate particles. In particular, magnetosheath jets with bow waves have electron energy flux enhanced on average by a factor of 2 compared to both those without bow waves and the ambient magnetosheath. Our study implies that magnetosheath jets can contribute to shock acceleration of particles especially for high Mach number shocks. Therefore, shock models should be generalized to include magnetosheath jets and concomitant particle acceleration.

Statistical Study of Oxygen Ions Abundance and Spatial Distribution in the Dayside Magnetopause Boundary Layer: MMS Observations

AbstractUsing energetic ion composition data at the dayside magnetopause measured by Magnetospheric Multiscale (MMS) satellites, we study the responses of H+, O+ density (1–40 keV), and their ratio to geomagnetic activity and solar wind conditions; their spatial distributions in the XYGSM plane for different ranges of the above parameters are presented as well. The dependencies of the H+ and O+ fluxes spatial distributions on different energy ranges are also investigated. Statistical results show that the dependencies of the H+ density on SYM‐H index, IMF By, and IMF Bz are weak, while the O+ density and its abundance (O+/H+) vary with SYM‐H index and solar wind dynamic pressure exponentially. The IMF directions not only affect the O+ density and its abundance but also play a major role in their spatial distributions. The O+ density shows duskside asymmetry under southward IMF with positive IMF By and shows dawnside asymmetry under northward IMF with negative IMF By. The influence of the dawn‐dusk IMF direction on dawn‐dusk asymmetry is significant. The positive and negative IMF By can strengthen the O+ duskside asymmetry and dawnside asymmetry when the IMF is southward and northward, respectively. Otherwise, as particle energy enhances from ~10 to ~35 keV, the H+ fluxes concentrate more on the duskside magnetopause boundary layer while the O+ fluxes dawn‐dusk asymmetry shows minor difference. This suggests that the H+ and O+ at energies below 40 keV experience different processes when they are transported to the dayside magnetopause boundary layer.

A survey of geomagnetic and plasma time lags in the solar-wind-driven magnetosphere of earth

Sixteen variables describing the state of the magnetosphere are examined in the years 1991–2007; the sixteen variables include nine geomagnetic indices plus seven measures of electron and ion precipitation into the atmosphere, the rate of substorm occurrence, the pressure and number density of the ion plasma sheet, the flux of substorm-injected electrons, and the radiation-belt electron flux. Eight other variables are used to represent the properties of the solar wind at Earth. To estimate the time lags between magnetospheric and solar-wind variables bivariate (two-variable) linear correlations, multivariate linear correlations, and vector-vector correlations are utilized. Using bivariate correlation the lag time of each magnetospheric variable with respect to each solar-wind variable is varied to obtain the maximum correlation coefficient. Using multivariate linear correlations, the time series of each magnetospheric variable is correlated with a linear combination of the eight time series of the eight solar-wind variables, with eight independent lead times on the eight solar-wind variables optimized to produce the largest multivariate correlation coefficient. The resulting time lag between each magnetospheric variable and each solar-wind variable is then catalogued. Additionally, the solar-wind variables that most-strongly affect each of the 16 magnetospheric variables are noted. A similar process of optimizing lag times on magnetospheric variables is performed during vector-vector correlations between a 9-dimensional magnetospheric state vector and an 8-dimensional solar-wind state vector.

Microscopic, Multipoint Characterization of Foreshock Bubbles With Magnetospheric Multiscale (MMS)

AbstractThis work presents the first detailed analysis of foreshock bubbles (FBs) using high‐resolution Magnetospheric Multiscale (MMS) data. Between October 2017 and January 2019, MMS captured 10 foreshock transient events with burst resolution data that we show are consistent with FBs. One “textbook” event is examined and described in detail. Employing the multipoint nature of MMS, we demonstrate how the size and orientation, expansion speed, and distance since formation can be estimated. From all 10 events, FB sizes ranged from 1.1 to 9.9 RE (average of 4.4 RE), and expansion speeds ranged from 139 to 377 km/s (average of 257 km/s). FBs formed under a usual range of solar wind conditions between 3 and 20 RE upstream of Earth's bow shock. We also report on new features of FBs: deep and localized magnetic “holes” within the cores of FBs, where the total field strength drops to &lt;1 nT.

Magnetic Energy Transfer and Distribution between Protons and Electrons for Alfvénic Waves at Kinetic Scales in Wavenumber Space

Abstract Turbulent dissipation is considered a main source of heating and acceleration in cosmic plasmas. The alternating current Joule-like term, , is used to measure the energy transfer between electromagnetic fields and particles. Because the electric field depends on the reference frame, in which frame to calculate is an important issue. We compute the scale-dependent energy transfer rate spectrum in wavevector space, and investigate the electric-field fluctuations in two reference frames: in the mean bulk flow frame and in the local bulk flow frame (non-inertial reference frame). Considering Alfvénic waves, we find that , which neglects the contribution of work done by the ion inertial force, is not consistent with the magnetic field energy damping rate (2γδB 2) according to linear Maxwell–Vlasov theory, while is exactly the same as 2γδB 2 in wavenumber space (k ∥, k ⊥), where γ is the linear damping rate. Under typical conditions of solar wind at 1 au, we find in our theoretical calculation that the field energy is mainly converted into proton kinetic energy leaving the residual minor portion for electrons. Although the electrons gain energy in the direction perpendicular to the mean magnetic field, they return a significant fraction of their kinetic energy in the parallel direction. Magnetic-field fluctuations can transfer particle energy between the parallel and perpendicular degrees of freedom. Therefore, and do not solely describe the energy transfer in the parallel direction and perpendicular direction, respectively.

MHD Modeling of the Background Solar Wind in the Inner Heliosphere From 0.1 to 5.5 AU: Comparison With In Situ Observations

AbstractThe accurate prediction of solar wind conditions in the interplanetary space is crucial in the context of both scientific research and technical applications. In this study, we simulate the solar wind throughout the heliosphere from 0.1 to 5.5 astronomical units (AU) with our improved heliospheric magnetohydrodynamics (MHD) model during the time period from 2007 to 2017. The model uses synoptic magnetogram maps as input to derive the inner boundary conditions based on a series of empirical relations such as the Wang‐Sheeley‐Arge (WSA) relation. To test the performance of this model, we compare the simulation results with in situ measurements from multiple spacecraft including ACE/WIND, Solar TErrestrial Relations Observatory, Ulysses, Juno, and MErcury Surface, Space ENvironment, GEochemistry, and Ranging at different latitudes and heliocentric distances. There is an overall agreement between the model results and solar wind observations at different latitudes and heliocentric distances. Statistical analysis for Year 2007 reveals that our model can predict most of the corotation interaction regions, high‐speed streams, and magnetic sector boundaries at 1 AU. In addition, the bimodal structure of the solar wind for different latitudes is well reproduced by the model which is consistent with Ulysses data. This study demonstrates the capabilities of our heliosphere model in the prediction of the large‐scale structures of the solar wind in the inner heliosphere, and the model can be used to predict the ambient solar wind at locations of planets in the solar system such as Earth and Jupiter.

Observation of Transition Boundary between Cold, Dense and Hot, Tenuous Plasmas in the Near-Earth Magnetotail

Properties of plasmas that constitute the plasma sheet in the near-Earth magnetotail vary according to the solar wind conditions and location in the tail. In this case study, we present multi-spacecraft observations by Cluster that show a transition of plasma sheet from cold, dense to hot, tenuous state. The transition was associated with the passage of a spatial boundary that separates the plasma sheet into two regions with cold, dense and hot, tenuous plasmas. Ion phase space distributions show that the cold, dense ions have a Kappa distribution while the hot, tenuous ions have a Maxwellian distribution, implying that they have different origins or are produced by different thermalization processes. The transition boundary separated the plasma sheet in the dawn-dusk direction, and slowly moved toward the dawn flank. The hot, tenuous plasmas filled the central region while the cold, dense plasmas filled the outer region. The hot, tenuous plasmas were moving toward the Earth, pushing the cold, dense plasmas toward the flank. Different types of dynamical processes can be generated in each region, which can affect the development of geomagnetic activities.

Upstream Ultra‐Low Frequency Waves Observed by MESSENGER's Magnetometer: Implications for Particle Acceleration at Mercury's Bow Shock

AbstractWe perform the first statistical analysis of the main properties of waves observed in the 0.05–0.41 Hz frequency range in the Hermean foreshock by the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) Magnetometer. Although we find similar polarization properties to the “30 s” waves observed at the Earth's foreshock, the normalized wave amplitude (δB/|B0|∼0.2) and occurrence rate (∼0.5%) are much smaller. This could be associated with relatively lower backstreaming proton fluxes, the smaller foreshock size and/or less stable solar wind (SW) conditions around Mercury. Furthermore, we estimate that the speed of resonant backstreaming protons in the SW reference frame (likely source for these waves) ranges between 0.95 and 2.6 times the SW speed. The closeness between this range and what is observed at other planetary foreshocks suggests that similar acceleration processes are responsible for this energetic population and might be present in the shocks of exoplanets.

Causal inference in space weather by an information theory approach

The variability of the interplanetary medium and solar wind conditions strongly affects the near-Earth environment causing several phenomena, such as the magnetic storms and substorms. Here, we present some preliminary results on the causal inference in the solar wind-magnetosphere-ionosphere coupling by means of information theory which could be helpful for Space Weather modeling.