SWP Solar Wind & Interplanetary Medium

Question 1

The Parker spiral describes:

Accepted Answer

The Archimedean spiral shape of the interplanetary magnetic field resulting from solar rotation and radial solar wind flow

Answer

Eugene Parker showed that the combination of radial solar wind outflow and solar rotation at 27 days causes the IMF to trace an Archimedean (Parker) spiral from the Sun to the outer heliosphere.

Question 2

At 1 AU, the average solar wind speed is approximately:

Accepted Answer

400–500 km/s

Answer

The ambient slow solar wind at 1 AU averages about 400–500 km/s; fast streams from coronal holes average 600–800 km/s, while CME sheaths can exceed 1000 km/s.

Question 3

A corotating interaction region (CIR) forms when:

Accepted Answer

A fast solar wind stream from a coronal hole runs into and compresses the slower ambient solar wind ahead of it

Answer

As the Sun rotates, a fast wind stream continually runs into the slower wind ahead, building up a compressed, dense interaction region that corotates with the Sun.

Question 4

The southward component of the interplanetary magnetic field (Bz) is critical for geomagnetic activity because:

Accepted Answer

Southward Bz enables magnetic reconnection at the dayside magnetopause, transferring solar wind energy into the magnetosphere

Answer

When IMF Bz is directed southward (antiparallel to Earth's northward equatorial field), dayside reconnection opens the magnetosphere, allowing solar wind momentum and energy to enter.

Question 5

The L1 Lagrange point (~1.5 million km sunward of Earth) is the preferred location for space weather monitors because:

Accepted Answer

It is gravitationally stable and provides ~15–60 minutes of advance warning before solar wind structures reach Earth

Answer

L1 is the neutral gravitational point between Earth and Sun where a satellite can maintain position with minimal fuel while measuring the undisturbed solar wind before it reaches Earth.

SWP - Space Weather Professional Certification Exam Practice Test

SWP - Space Weather Professional Certification Exam Practice Test

SWP Solar Wind & Interplanetary Medium