The high-speed solar wind runs away from the sun into the deep space, and when it approaches the planet, hits the atmosphere of the planet and blows away some part of atmosphere depending on the speed and energy of particles of solar wind. The magnetic field of planets plays important roles at this time in the protection of the atmosphere. The interaction between the magnetic field and solar wind creates bow shock. Magnetosphere causes the particles to travel around the planet rather than bombarding the atmosphere and surface.
What is solar wind?
The solar wind is a stream of charged particles released from the upper atmosphere of the Sun. Solar wind mostly consists of electrons and protons, the temperature and speed of particles vary with time. The particles are able to escape the Sun’s gravity because of their high kinetic energy and the high temperature of the corona.
Since solar wind has high energy particles, these particles can easily affect the atmosphere of planets which are present very close to the Sun. The solar wind usually has such a high energy that it shows its impact up to the boundary of the solar system where it creates the Heliosphere after interaction with the particles of the interstellar medium. There are many phenomena caused by solar wind some of which are given below:
Formation of Aurora due to Solar Wind
The solar wind consists of high energy particles when these particles approach Earth they are trapped and dragged by the magnetic field of Earth toward the poles. At poles, these high-energy particles collide with the molecules of atmosphere and excite them. After some time, these excited molecules returns to their normal states and lose energy in the form of emission of visible lights.
The emitted color depends on the molecule of the atmosphere; the normally observed colors are red, green and blue. The combination of these colors creates beautiful patterns in the form of curtains and diffused patterns. These colored patterns are called aurora and these are found around the region of poles.
Solar Wind blows some part of the atmosphere of Earth into space
In September 1998, residents of the far north observed a massive display of the aurora borealis along with the fountain of gas being accelerated into space by a powerful bubble of the solar wind which pumped about 200 gigawatts of electrical power into the Earth.
At the same time, a special space weather research satellite was taking measurement showing that solar events can directly affect our outer atmosphere.
“This is the first time we’ve been able to correlate these solar coronal mass ejections (CMEs) with enhanced ion outflows from the upper ionosphere”, said Dr. James span on NASA’s Marshall Space Flight Center.
Atmosphere of Earth expands and contracts due to Solar Wind
When the high-speed solar wind reaches Earth, they cause the gasses in the upper atmosphere to heat up and expand, then cool down and contract. It causes the change in density of the upper atmosphere and creates high and low-density regions.
Orbiting satellite when flies through the resulting “hills and valleys of density” experiences more or less drag. Satellite faced with the denser atmosphere will slow down and need more energy to keep moving in given orbit.
The changes in drag affect satellite’s ability to stay on the path; require more fuel and complex orbital adjustments to maintain the predictable and safe path.
Escape of atmosphere of Mars to space due to Solar Wind
Space physicists from the University of Leicester have identified that the pressure of solar wind is the main contributor to Mars atmospheric escape. It is observed that Mars atmosphere does not drift away at a steady; instead, atmosphere escape occurs in bursts.
Corotating interaction regions (CIR) are formed when regions of fast solar wind encounter slower solar wind, creating a high-pressure pulse. When these CIR pulses pass by Mars, they can drive away particles from Mars atmosphere.
The main reason of loss of atmosphere of Mars is the absence of Magnetic field produced by the planet which helps in protection from solar wind.
Changes in Sea-Level Pressure over South Korea Associated with High-Speed Solar Wind Events
Heon Young Chang and his colleagues performed analysis on data collected from 1986 to 2011 to explore a possible response of the Sea Level Pressure (SLP) over South Korea to the high-speed solar wind event. The change in Sea Level Pressure shows an increase up to 2.5 hpa at day +1 and a gradual decrease to its normal level, whose Key dates is defined such that whose daily solar wind speed at maximum exceeds 800 Km/s. They find that the SLP in a low latitude region shows a measurable response to an encounter of the high-speed solar wind as seen in the high latitude region.
Effect of transient solar wind pulses on heating the atmosphere of Jupiter
The Jovian upper atmosphere temperature is up to 700 K higher than that predicted by solar heating alone. The energy crisis at Jupiter and the other giant planets have puzzled scientists for over 40 years.
Clarke et al, (2009) and Nichols et al, (2000) studied the effect of transient changes in solar wind dynamic pressure on Jovian auroral parameters and thermospheric energy budget. The transient magnetospheric changes simulated are of two types i) a transient compression event and ii) a transient expansion event, both of which last for three hours. Observations by them find the factor of two increases in auroral brightness, as well as poleward shifts up to 1 degree due to the arrival of solar wind shocks. The magnetospheric super-corotation results in 2000 TW resultant power being dissipated in thermosphere which leads to the local temperature change of 25 K.
All the above phenomena clearly show that solar winds are very powerful. There are many other problems that are caused by the solar wind like damage of satellites, the problem in communication, and damage to the ozone layer. Therefore it is very important to develop protection against the solar wind in the interplanetary space probe. The solar wind is harmful to both humans as well as instruments. With the development of technology, we will be able to protect us against the solar wind in the future interplanetary missions.