Close, but this is in fact the circumhorizontal arc. It’s very similar to the cza, but the refractions happen in the opposite order. The cha occurs below the sun when the sun is high, the cza occurs high above the sun (near the zenith) when the sun is low.
Nice pictures!
Not an arcus, but what looks to be a series of Stratocumulus volutus. Nice find nonetheless!
Arcus is a supplementary feature attached to a strong convective cloud (Cumulonimbus or possibly a strong Cumulus). This isn’t the case here.