Can a magus use his arcane pool on a ranged weapon?

[Sagotel]

The magus would normally be in mêlée, not using ranged attacks, but versatility is good. A +1 bow would be useful on occasion.

[Name Violation]

yes. any weapon

At 1st level, a magus can expend 1 point from his arcane pool as a swift action to grant any weapon he is holding a +1 enhancement bonus for 1 minute. For every four levels beyond 1st, the weapon gains another +1 enhancement bonus, to a maximum of +5 at 17th level. These bonuses can be added to the weapon, stacking with existing weapon enhancement to a maximum of +5. Multiple uses of this ability do not stack with themselves.

At 5th level, these bonuses can be used to add any of the following weapon properties: dancing, flaming, flaming burst, frost, icy burst, keen, shock, shocking burst, speed, or vorpal.

[Sagotel]

I wish I had known (or thought of) that when I was pumping arrows into a monster that was attacking my ally in a pit.

[Nefreet]

An especially useful tactic for all those Dex-based Magi.

[Dragonchess Player]

It's one of the things that makes magus (myrmidarch)/arcane archer 3 so versatile. Imbue Arrow with area spells, Ranged Spellstrike with ranged touch spells, Enhance Arrows (Elemental) for "free" flaming, frost, or shock arrows all day, Arcane Pool to add enhancement bonuses and/or weapon abilities to any weapon, regular Spellstrike for melee (both standard touch and ranged touch spells with the Close Range arcana), etc.