Measuring Information Coupling between the Solar Wind and the Magnetosphere-Ionosphere System

Area of Science:

• Space Physics
• Geophysics
• Complex Systems Analysis

Background:

• The solar wind's interaction with Earth's magnetosphere-ionosphere system is complex.
• Accurately modeling this interaction requires understanding causal relationships between parameters.
• Traditional statistical and Granger causality models struggle with these complex time series.

Purpose of the Study:

• To apply information theory concepts to measure causal information in the solar wind-magnetosphere-ionosphere system.
• To identify key drivers of the magnetosphere-ionosphere response to solar wind changes.
• To improve Space Weather modeling capabilities.

Main Methods:

• Utilized information theory-based concepts for model-free causal relationship detection.
• Analyzed time series data from solar wind and geomagnetic indices.
• Quantified information transfer between different solar wind parameters and geomagnetic responses.

Main Results:

• A time delay of 30-60 minutes was observed between solar wind and magnetosphere-ionosphere dynamics.
• Significant information transfer was found between the interplanetary magnetic field's Z-component (IMF B z) and geomagnetic indices.
• Other solar wind parameters showed lower information transfer, indicating IMF B z as a primary driver.

Conclusions:

• The interplanetary magnetic field's Z-component (IMF B z) is the most effective parameter for modeling geomagnetic responses to solar wind variations.
• Information theory provides a robust framework for analyzing complex causal links in space physics.
• These findings are crucial for advancing Space Weather prediction and understanding.