On 2000 August 25 from Lynn Lake, Manitoba, we conducted a balloon flight of the LEE/AESOP (Low Energy Electrons/Anti-Electron Sub Orbital Payload) payload to measure the spectrum of cosmic-ray electrons (resolved into negatrons and positrons) from 500 MeV to 3 GeV. Analysis of the data from that flight reveals a significant decrease in the cosmic-ray positron abundance from a level that remain...

Gamma ray emission lines resulting from accelerated particle bombardment of ambient gas can serve as an important spectroscopic tool for abundance determinations. The method is illustrated by considering the gamma ray line emission observed from solar flares. The observation of similar gamma ray lines from Orion suggests the existence of large fluxes of low energy Galactic cosmic rays. The role...

[1] The indirect radiative forcing of atmospheric aerosols is sensitive to particle size and concentration, which are influenced significantly by nucleation processes. Via its role in aerosol formation, cosmic ray may affect the cloud condensation nuclei abundance and hence the global cloud properties and climate. Systematic variations in ionization rates due to the modulation of cosmic ray rad...

An expression for maximum accelerated particle energy Emax due to the firstorder shock-Fermi process is generalized to relativistic flows. Given the Bohm diffusion approximation and a mean ISM magnetic field of 3μG, then Emax ≈ 8 × 10β0Z(m⊙/n0) 1/3 eV for an uncollimated explosion expanding into a uniform medium with density n0. The initial flow speed of the explosion is β0c, and the total ejec...

The phenomenon of the double-peak solar cycle structure (Gnevyshev, 1963) is used to study the solar cosmic ray origin. Solar proton events are diminished in number and energetic particle intensity during the maximum solar activity phase. It is shown that during the same time periods the Ground Level Enhancements disappeared almost simultaneously with solar flares of large area and long lasting...

Recent outer-heliosphere observations are reviewed from a space weather point of view by comparing the nature of solar wind, solar particle, and cosmic ray variations at the Voyagers and 1 AU. While the Sun still controls the interplanetary medium at 75 AU, the nearby boundaries of the heliosphere exert a strong influence on the environment.

Time dependent cosmic ray modulation in the inner heliosphere is studied by comparing results from a 2D, time-dependent cosmic ray transport model with Ulysses observations. A compound approach, which combines the effects of the global changes in the heliospheric magnetic field magnitude with drifts to establish a realistic timedependence, in the diffusion and drift coefficients, are used. We s...

The solar wind modulates the flux of galactic cosmic rays impinging on Earth inversely with solar activity. Cosmic ray ionisation is the major source of air’s electrical conductivity over the oceans and well above the continents. Differential solar modulation of the cosmic ray energy spectrum modifies the cosmic ray ionisation at different latitudes, varying the total atmospheric columnar condu...

The ability to predict times of greater galactic cosmic ray (GCR) fluxes is important for reducing the hazards caused by these particles to satellite communications, aviation, or astronauts. The 11-year solar cycle variation in cosmic rays is highly correlated with the strength of the heliospheric magnetic field. Differences in GCR flux during alternate solar cycles yield a 22-year cycle, known...

Observations of cosmic-ray helium energy spectra provide important constraints on cosmic ray origin and propagation. However, helium intensities measured at Earth are affected by solar modulation, especially below several GeV/nucleon. Observations of helium intensities over a solar cycle are important for understanding how solar modulation affects galactic cosmic ray intensities and for separat...