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Published on: February 13, 2018
Nonlinear development of shocklike structure in the solar wind
1Space Sciences Laboratory, University of California, Berkeley, California 94720, USA. eslee@ssl.berkeley.edu
Physical Review Letters
|August 8, 2009
Summary
Scientists observed nonlinear steepening of solar wind pulses near Earth's bow shock. Ion thermalization mechanisms differ in the early shock development phase, impacting magnetic field and ion dissipation differently.
Area of Science:
- Space Physics
- Plasma Physics
- Astrophysics
Background:
- The solar wind is a continuous stream of charged particles from the Sun.
- Earth's bow shock is a boundary where the solar wind abruptly slows down.
- Understanding shock formation is crucial for space weather prediction.
Purpose of the Study:
- To investigate the initial stages of shock formation in the solar wind.
- To analyze the nonlinear steepening of compressional pulses.
- To differentiate the mechanisms of ion and magnetic field dissipation.
Main Methods:
- In situ multispacecraft observations.
- Analysis of magnetic field and plasma data.
- Identification of shocklike structures and ion behavior.
Main Results:
- First in situ observations of nonlinear pulse steepening upstream of the bow shock.
- Compressional pulses break and steepen into shocklike structures.
- Ion thermalization is minimal initially but significant at the steepened edge.
Conclusions:
- The mechanisms for magnetic field and ion dissipation are distinct in the early phase of shock development.
- Gyrating ions play a role in the later stages of thermalization.
- These findings advance our understanding of collisionless shock formation.
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