INCREASES IN SCR ENERGETIC PROTON FLUXES ON EARTH AND THEIR RELATION TO SOLAR SOURCES

Logachev catalog data for solar cycle 23 has been used to study the dependence of measured increases in solar cosmic rays (SCRs) on solar perturbations. The efficiency of recording the SCR increases, driven by proton acceleration in the corona, on Earth and in its vicinity is shown to depend on power of a solar flare that created a shock wave and on position of the flare on the solar disk. As the particle flux moves along the heliolongitude away from the parent flare, the acceleration efficiency decreases, i.e. the maximum energy of the accelerated particles and their intensity at equal energy decrease. As a result, at a certain distance along a heliolongitude from the parent solar flare, the solar proton flux intensity decreases to the galactic background, and there is no SCR increase detected.

INCREASES IN SCR ENERGETIC PROTON FLUXES ON EARTH AND THEIR RELATION TO SOLAR SOURCES

Logachev catalog data for solar cycle 23 has been used to study the dependence of measured increases in solar cosmic rays (SCRs) on solar perturbations. The efficiency of recording the SCR increases, driven by proton acceleration in the corona, on Earth and in its vicinity is shown to depend on power of a solar flare that created a shock wave and on position of the flare on the solar disk. As the particle flux moves along the heliolongitude away from the parent flare, the acceleration efficiency decreases, i.e. the maximum energy of the accelerated particles and their intensity at equal energy decrease. As a result, at a certain distance along a heliolongitude from the parent solar flare, the solar proton flux intensity decreases to the galactic background, and there is no SCR increase detected.

The Effect of Solar-Wind Turbulence on Magnetospheric Activity

The solar wind is a highly turbulent medium exhibiting scalings of the fluctuations ranging over several decades of scales from the correlation length down to proton and electron gyroradii, thus suggesting a self-similar nature for these fluctuations. During its journey, the solar wind encounters the region of space surrounding Earth dominated by the geomagnetic field which is called magnetosphere. The latter is exposed to the continuous buffeting of the solar wind which determines its characteristic comet-like shape. The solar wind and the magnetosphere interact continously, thus constituting a coupled system, since perturbations in the interplanetary medium cause geomagnetic disturbances. However, strong variations in the geomagnetic field occur even in absence of large solar perturbations. In this case, a major role is attributed to solar wind turbulence as a driver of geomagnetic activity especially at high latitudes. In this review, we report about the state-of-art related to this topic. Since the solar wind and the magnetosphere are both high Reynolds number plasmas, both follow a scale-invariant dynamics and are in a state far from equilibrium. Moreover, the geomagnetic response, although closely related to the changes of the interplanetary magnetic field condition, is also strongly affected by the intrinsic dynamics of the magnetosphere generated by geomagnetic field variations caused by the internal conditions.

Turbulence and Plasma Inhomogeneity Observed by Swarm Constellation

<p>The ionospheric environment is a complex system where dynamic phenomena, such as turbulence (fluid and magnetohydrodynamics) and plasma instabilities generally occur as a consequence of the coupling processes among solar wind, magnetosphere and ionosphere. It has been suggested that the turbulent character of the ionospheric plasma density also enters into the formation and dynamics of ionospheric inhomogeneities and irregularities, which essentially characterize the active equatorial, mid-latitude and polar regions. The ionospheric turbulence indirectly plays an important role also in the framework of space weather when due to the arrival of solar perturbations the plasma, the energetic particle distributions, the electric and magnetic fields within the magnetosphere and ionosphere are deeply modified thus paving the way for an increase in the ionospheric turbulence. Recent findings within the ESA funded project “Characterization of IoNospheric TurbulENce level by Swarm constellation (INTENS)” permitted us to investigate the role played by the turbulence on scales from hundreds of kilometers to a few kilometers in generating multi-scale plasma structures and inhomogeneities in the ionospheric environment at different latitudes. This presentation reports on the most promising results of the INTENS project regarding the investigation of turbulence and plasma conditions in the topside ionosphere using Swarm data.</p>

Is a whole-mantle convection the key to solving the Tunguska 1908 problem?

<p>It is generally accepted that the Tunguska event in Siberia on 30 June, 1908 resulted from an explosion of cosmic body. However, there is no common agreement that this bolide really existed. Moreover, registered ultra low frequency (ULF) magnetic oscillations in Kiel, Germany on 27-30 June 1908 [1] had a correlate with the 'acoustic halo' (ULF) of a solar flare [2].</p><p>Large low-shear velocity provinces (LLSVPs) are linked to so-called blobs located atop the Earth's outer core [3]. It was shown the Earth's D"-layer core-mantle boundary was perturbed by both the solar flare and an anomalous lunar-solar tide during the Tunguska 1908 event [2]. Therefore, gravitational/magnetic lunar-solar perturbations could have triggered a plume/hotspot/LIP activation by means of a LLSVPs convection.</p><p>It was suggested that planetary hotspots chains are interconnected [4]. Indeed, during the Tunguska event brightest glows were observed over the Eifel volcano and more weak one over the Yellowstone volcano (both volcanoes are associated with hotspots) [5]. In addition, day by day a slowly lifting of the earth round the diabase stones was registered in Tasmania from 7 June till 29 June, 1908 [6]. This lifting was independent from atmospheric temperature variations and terminated as soon as a blast took place in the caldera of Tunguska paleovolcano on 30 June, 1908 [5, 6]. Observations in Tasmania remained a mystery for a long time. Recently scientists discovery the Cosgrove hotspot had moved from Eastern Australia to Tasmania [7]. In our opinion, the Cosgrove did not lose its activity fully 9 My ago as previously assumed: the Darwin crater in Tasmania originated about of 803 ka years and large volume ejected glasses in/around this small crater contradicts to the impact origin [5, 8]. Therefore, we consider the underground activation of Cosgrove hotspot as a cause of surface uplift in Tasmania from 7 to 30 June 1908.</p><p>As in Tasmania, moving mantle hotspots were registered in Eastern Siberia [9]. Probably, hotspots in Tasmania (near Pacific LLSVPs) and in the Tunguska basin (near Perm LLSVPs) are interconnected. Because common hotspots thermal energy was released in/by the Tunguska paleovolcano explosion on 30 June 1908, the fluidal pressure of the Cosgrove hotspot under Tasmania was reduced, resulting in the termination of surface uplift. Since meteorites could not have caused the earth uplift in Tasmania, the impact hypothesis for the Tunguska phenomenon can be excluded. All data favor an endogenic origin of this event due to lunar-solar perturbations and the whole-mantle convection.</p><p><span>[1]. Weber L. (1908) Astronomische Nachrichten, </span><strong><span>178</span></strong><span>, 23. [2]. German B. (2010) EPSC2010-430. [3]. Duncombe J. (2019) Eos, </span><strong><span>100</span></strong><span>. [4]. Courtillot V. (1990) ISBN 9780813722474, 401. [5]. German B. (2019) ISBNs 9783981952605(in Russian)/9783981952612(in English). [6]. Scott H. (1908) Nature, </span><strong><span>78</span></strong><span>(2025), 376. [7]. Davies D. (2015) Nature, </span><strong><span>525</span></strong><span>, 511. [8]. Haines P. (2005) Australian Journal Earth Sciences, </span><strong><span>52</span></strong><span>, 481. [9]. Rosen O. (2015) ISBN 9785902754954, 148.</span></p>