Which of the following phenomenon on Earth is directly triggered by the...

[Stacey L]

...solar activities? a) tsunami
b) earth quakes
c) high tides
d) aurora
e) meterorite shower

i chose earth quakes..i'm probably wrong..i'm so enthusiastic about astronomy!

[Luis A]

d) aurora..

The Earth is constantly immersed in the solar wind, a rarefied flow of hot plasma (gas of free electrons and positive ions) emitted by the Sun in all directions, a result of the million-degree heat of the Sun's outermost layer, the solar corona. The solar wind usually reaches Earth with a velocity around 400 km/s, density around 5 ions/cc and magnetic field intensity around 2–5 nT (nanoteslas; Earth's surface field is typically 30,000–50,000 nT). These are typical values. During magnetic storms, in particular, flows can be several times faster; the interplanetary magnetic field (IMF) may also be much stronger.

The IMF originates on the Sun, related to the field of sunspots, and its field lines (lines of force) are dragged out by the solar wind. That alone would tend to line them up in the Sun-Earth direction, but the rotation of the Sun skews them (at Earth) by about 45 degrees, so that field lines passing Earth may actually start near the western edge ("limb") of the visible sun.[4]

[Elizabeth H]

aurora or polar lights are a consequence of activity on the sun, and are commonest at times of solar maxima.

[edward_otto@sbcglobal.net]

D) aurora.