(ORDO NEWS) — An international team of astrophysicists has studied the occurrence of ion holes in the tail of the earth’s magnetosphere and assessed their impact on space weather.
They found that ion holes propagate obliquely to the local magnetic field. The results of the study will allow a better understanding of the physics of near-Earth plasma, which determines space weather in near-Earth space and in the polar regions of the Earth.
The near-Earth space is filled with plasma. Its behavior affects the weather in this space, in other words, space weather.
To predict how it will change, it is important to know what kind of waves exist in the plasma and how they behave. Scientists have more than a dozen types of different waves, one of them is solitary waves with negative polarity, or ion holes.
Until recently, this type of waves was practically not studied, but the launch of new generation satellite missions equipped with more accurate instruments made it possible to carry out their detailed measurements.
Today, scientists collect wave statistics, study their main parameters in order to understand how important these waves are for space weather and how to build a model for predicting it in near-Earth space.
To collect statistics on ion holes, American researchers led by Professor Forrest Moser of the University of California used data from four space satellites. It turned out that there are many of these waves in the tail of the Earth’s magnetosphere, on its night side.
It is from this side that the movement of plasma particles begins, which fall on the Earth in the form, for example, of auroral auroras, known to us as northern ones.
All four Magnetospheric Multiscale (MMS) Mission spacecraft observed 150 ion holes around a fast plasma stream in the Earth’s plasma sheet.
The researchers were faced with the task of registering the same wave on neighboring vehicles of the MMS mission in order to calculate its speed and direction of propagation.
By combining this data with measurements of the magnetic field, the scientists found that the observed waves can propagate at significant angles to the magnetic field.
Large tilt angles allow the waves to effectively scatter and heat plasma particles. In turn, the flows of charged particles contribute to the formation of the observed waves.
The study of plasma physics became popular when scientists became interested in creating new energy sources based on thermonuclear fusion.
This process was studied for a long time on the basis of laboratory plasma studies, until it was found that the space around the Earth is not empty and is also filled with plasma with similar properties.
Therefore, in addition to expensive laboratory studies, it was decided to use space satellites to study the plasma of the near-Earth space.
In the process of research, however, it turned out that the study of plasma in near-Earth space has its own value. Changes in near-Earth weather can affect satellites. For example, a solar flare can disable expensive equipment on satellites.
To determine whether this will happen, one must understand the physics of near-Earth plasma. Thus, a branch of thermonuclear physics became an independent area of research – the study of space weather.
“Studying near-Earth plasma allows us to better understand the physics of distant and inaccessible astrophysical objects, such as shock waves, that cannot be directly measured.
Shock waves are rapidly expanding plasma clouds, inside of which there are many small waves in constant motion . Among them are ion holes.
It is important to understand how these small waves behave, at least using the example of near-Earth plasma. Shock waves are one of the main sources of cosmic rays and affect the earth’s weather and people’s health,” Sergey Kamaletdinov said.
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