It has long been established that magnetic storms not only affect the performance of equipment, upset radio communications, blackout radars, and disrupt radio navigation systems but also endanger living organisms. They change the blood flow, especially in capillaries, affect blood pressure, and boost adrenalin.
The young and fit couldn’t care less, but those who are older, may develop problems. They have to consider the state of magnetosphere in their daily plans. Before, people were glued to weather forecasts. Now they are obsessed with the geomagnetic situation.
But what is a magnetic storm?
Shortly after the launch of the first satellites, mankind discovered the solar wind – a continuous flow of hot plasma from the solar corona. At a distance of 10-12 Earth’s radii in the direction of the Sun, where the energy of the solar wind equals that of the Earth’s magnetic field, solar wind particles change their direction, and flow around the Earth, forming a comet-like plasma vacuum — the magnetosphere. The size of its sophisticated but fairly stable structure depends on solar wind pressure, and hence, on solar activity.
The tail of the magnetosphere, which stretches for hundreds of thousands of kilometers in the direction opposite to the Sun, accumulates magnetic energy. From time to time, it is released in explosions, which heat up plasma, and create powerful electric currents (millions of amperes). When such bursts follow one another, the magnetosphere is filled to capacity with hot plasma, while its electric currents embrace the entire near-Earth space. These phenomena are referred to as magnetic storms.
The heart and cardio-vascular system have always been considered the main biological targets of geomagnetic activity. However, the damage inflicted by magnetic storms on human health has been found to be different. Experts from the Institute of Space Studies of the Russian Academy of Sciences (RAS), Institute of Physics of the Earth (RAS), and the Sechenov Moscow Medical Academy have established that the biggest danger emanates from the micro variations of the geomagnetic field, which coincide with the heartbeat. They occur in about half of all magnetic storms, and are most typical for a prelude to a storm with insignificant changes in the geomagnetic field (mostly affecting high altitudes), and for the recovery phase, when the geomagnetic field is coming back to normal.
Medical statistics for Moscow show that 70% of all micro variations, caused by geomagnetic disturbances, are accompanied by an abnormally high incidence of heart attacks (a growth of about 13%), and blood-strokes (7.5% growth). The low and extremely low frequency electromagnetic fields destabilize the heartbeat, leading to a sudden death or infarction. Medical experts have finally explained why heart attacks take a heavy toll before a magnetic storm – because micro variations begin 24 hours before the storm.
“We have analyzed numerous data on the heartbeat of cosmonauts from all Soyuz crews, and the majority of missions to the Mir Station and the International Space Station,” said Doctor Tamara Breus (Physics and Mathematics) from the Russian Academy of Sciences’ Institute of Space Studies, who heads of a group of physics and physicians, studying this problem.
“We subjected 45 cosmonauts to examination during landing and flights of various duration, when they were exposed to geomagnetic disturbance, and then studied the same parameters in a neutral situation,� he said.
“The influence of a magnetic storm was obvious. It was manifest in a change of pulse and blood pressure, vegetative disorders, reduction of heartbeat rate variability and the power of respiratory undulations, and in a more irregular heartbeat pattern. Reactions varied depending on the duration of the flights and an ability of cosmonauts to adapt themselves to the new environment.”
In the opinion of Dr. Breus, these effects were a reaction of the vascular tonus and heartbeat rhythm to magnetic storms.
It is perfectly obvious that the response of such a complicated system as the human organism to external factors largely depends on its condition. A magnetic storm is not dangerous for healthy people.
But there are risk groups with unstable biological status. These include people suffering from ischemic disorders or hypertension, or children whose adaptation system is the process of formation. Newly born are particularly at risk.
“We think that simply forecasting storms is counterproductive because people merely get scared as a result,” said Dr. Breus. “But steady micro variations are different. We should concentrate on this in forecasting geomagnetic disturbances.”
What is the situation with forecasts today?
Owing to the research, conducted under the comprehensive program of Interbol, scientists better understand the nature of cause-and-effect connections in the near and remote space, which helps them develop the methods of space weather forecasts, that is, distance and time variations of space parameters caused by solar activity.
Since 1994, Russia has been implementing its KORONAS program (Comprehensive Orbital Near-Earth Monitoring of Solar Activity) with a series of space vehicles. The third satellite – KORONAS-Foton – will be launched under the program in 2007.
Continuous monitoring of the solar wind is critical for space weather forecasts. The Chibis micro satellites, which are being developed by the Institute of Space Studies, will be working to this end in low-orbit ionosphere in the near future.
Space vehicles of the Institute’s another project – Resonans – will do the monitoring in the internal magnetosphere, and the radiation belts. One more satellite – probably the same Chibis – will stay at the top – in the so-called libration point at a distance of about one and a half million kilometers from the Earth.
The gravitational forces of the Earth and the Sun are essentially in balance at this point, and for this reason a space vehicle may “linger on” for a long time near the Sun-Earth line, along which harmful solar corona ejections move, timely reporting the emergence of dangerous solar bursts.
To receive an earlier warning, a space vehicle may be “removed” even further from the Earth. Researchers from the Institute of Space Studies have developed a project called Klipper (not to be confused with a new Russian re-usable piloted spaceship), which provides for placing micro satellites at a distance of 3 to 4 million kilometers from the Earth in the Sunward direction.
This is twice further than the libration point. “Excessive” gravitation of the Sun (compared to the libration point) will be compensated for by the pressure of sunlight on a sail made of fine metallic-like coating on board the satellites. In this way, researchers will be able to stabilize the satellites at a certain point in space, or move them closer to the Sun by handling the reflecting sail.
In other words, they will manipulate the reflecting powers of the material from which it is made. For instance, if a liquid-crystal fiber is installed between a source of light (the Sun in this case), and the sail, it is possible to change the transparency of the fiber by putting it under electric voltage (or removing it).
Its reflecting powers may be changed from mirror reflection to total absorption. This will affect the pressure of light on the sail, causing a change in the direction and speed of the satellite’s movement in space.
A project of solar research at a closer distance – Intergeliozond – is designed for a more remote perspective. It will make it possible to see the Sun’s polar zones, which are invisible from the Earth.