Solar and Heliospheric Modulation of Galactic Cosmic Rays

Abstract

The significance of external influences on the environment of Earth and its atmosphere has become evident during recent years. Especially, on time scales of several hundred years, the cosmogenic isotope concentration during the Wolf-, Spoerer-, Maunder-and Dalton-Minimum indicates an increased cosmic ray flux. Because these grand minima of solar activity coincide with cold periods, a correlation of the Earth climate with the cosmic ray intensities is plausible. Any quantitative study of the effects of energetic particles on the atmosphere and environment of the Earth must address their transport to Earth and their interactions with the Earth's atmosphere including their filtering by the terrestrial magnetosphere. The first problem is one of the fundamental problems in modern cosmic ray astrophysics, and corresponding studies began in the 1960s based on Parker's cosmic ray modulation theory taking into account diffusion, convection, adiabatic deceleration, and (later) the drift of energetic particles in the global heliospheric magnetic field. It is well established that all of these processes determining the modulation of cosmic rays are depending on parameters that are varying with the solar magnetic cycle. Therefore, the galactic cosmic ray intensities close to Earth is the result of a complex modulation of the interstellar galactic spectrum within the heliosphere. The modern view of this cosmic ray modulation is summarized in our contribution.

Raios cósmicos e a heliosfera

“…Emépocas em que A > 0 espera-se que os GCR com carga elétrica positiva derivem para dentro da heliosfera na direção dos polos do Sol e saiam através da HCS, enquanto as partículas negativas seguem o trajeto inverso. Emépocas em que A < 0 a deriva das partículasé revertida e as partículas positivas adentram pela HCS enquanto as negativas o fazem em direção aos pólos do Sol [43].…”

The Effects of Space Weather on Hurricane Activity

“…Yet, due to the well known anticorrelation between CR and SN (e.g. Heber et al, 2006) it is difficult to tell which of the two mechanisms is at work, or what combination of the two. Even more, it is still uncertain whether these mechanisms take place in the atmosphere and if their effect on clouds are measurable.…”

Cosmic Ray Associated with Coronal Index and Solar Flare Index during Solar Cycle 22 - 23

“…The numbers of sunspots were generally used as a reliable parameter to measure solar activity [3] [4] [5]. The 11-year's variation in the intensity of cosmic ray observed on the The solar modulation of cosmic ray intensity has been studied in recent decades using data from ground based detectors, in combination with various solar activity and solar-terrestrial relations [7] [8] [9] [10] [11]. Galactic cosmic rays in the energy range from several hundreds MeV to tens of GeV are subjected to heliospheric modulation, under the influence of solar output and its variation.…”