SWP Solar Wind & Interplanetary Medium 2

Question 1

The transit time of a CME from the Sun to Earth at 1 AU typically ranges from:

Accepted Answer

1–3 days

Answer

Most CMEs travel between about 300 and 2000 km/s, yielding a typical Sun-to-Earth transit time of 1 to 3 days, though extreme events can arrive in under 17 hours.

Question 2

Solar wind dynamic pressure (nmpv²) is important to magnetospheric forecasting because:

Accepted Answer

Higher pressure compresses the magnetopause earthward, intensifying field-aligned currents

Answer

Increased solar wind ram pressure compresses the magnetosphere, moving the magnetopause inward and energizing ring current and field-aligned current systems.

Question 3

A 'magnetic cloud' is a subset of CMEs identified by:

Accepted Answer

Smoothly rotating magnetic field, low proton temperature, and low plasma beta

Answer

Magnetic clouds show the classic flux rope signature: rotating IMF vector, depressed proton temperature (indicating expansion), and low beta (magnetic pressure dominates over thermal).

Question 4

The Forbush decrease is a reduction in galactic cosmic ray flux at Earth caused by:

Accepted Answer

CME passage shielding Earth's environs with a magnetically closed structure that deflects cosmic rays

Answer

As a CME and its magnetic sheath pass Earth, the enhanced and disordered magnetic fields within the CME structure scatter and exclude galactic cosmic rays, causing a temporary flux decrease.

Question 5

Which instrument aboard DSCOVR provides the primary real-time solar wind data used for space weather operations?

Accepted Answer

Faraday cup / electron electrostatic analyzer (plasma instrument) and fluxgate magnetometer

Answer

DSCOVR's PlasMag instrument suite includes a Faraday cup for solar wind density/speed/temperature and a fluxgate magnetometer for IMF Bx, By, Bz — the key operational inputs for storm forecasting.

SWP - Space Weather Professional Certification Exam Practice Test

SWP - Space Weather Professional Certification Exam Practice Test

SWP Solar Wind & Interplanetary Medium 2