Solar cycle and interplanetary hydrogen.
Abstract
The response of the interplanetary hydrogen gas to the solar cycle variations in the solar radiation field and in the solar wind is studied. The solar cycle in the radiation field also affects the photoionization rate and modifies the radiation pressure force. The solar wind, which is the main ionizing agent for hydrogen, has a strong solar cycle variation. We have calculated the density and velocity distributions of the interplanetary hydrogen gas including the time-dependent forces and ionizations. The calculation is carried out by the Monte Carlo simulation. The time-dependent solution shows the alternation of the travelling density waves and the depletion regions in the downwind side of the Sun. The time-dependent features are enhanced if the initial temperature of the incoming gas is low. In the case of the Sun the high temperature of the interplanetary gas reduces the magnitudes of the time-dependent structures but the variations are still considerable. The observed features in the time-dependent problem are related to the stationary state solution which is possible to solve analytically.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- August 1994
- Bibcode:
- 1994A&A...288..299K
- Keywords:
-
- Hydrogen;
- Interplanetary Gas;
- Plasma Interactions;
- Solar Cycles;
- Solar Radiation;
- Solar Wind;
- Variations;
- Density Distribution;
- Monte Carlo Method;
- Particle Trajectories;
- Photoionization;
- Radiation Pressure;
- Temperature Distribution;
- Time Dependence;
- Velocity Distribution;
- Solar Physics;
- INTERPLANETARY MEDIUM;
- SUN: SOLAR WIND;
- SUN: ACTIVITY;
- SOLAR NEIGHBOURHOOD