Both forms are correct. Artic and Arctic are two different words with similar spellings. Both are nouns, but one is an abbreviation for articulated vehicle and another is the name of a geographic region. The pronunciations of these words are comparable, but not the same, artic is pronounced like / (ɑːˈtɪk) / and Arctic-like /ˈɑːk.tɪk/. Although the words may easily be mistaken, they have absolutely different meanings.

Correct spelling


Correct spelling, explanation: an abbreviation for articulated vehicle.

Correct spelling


Correct spelling, explanation: name of a geographic region.

Definition of artic:
noun: a short for an articulated vehicle; a long vehicle with a trailer like a lorry;
I am scared sometimes when a big artic is passing near me on a freeway.
My dream as a boy was to become a professional driver and drive artics through the whole country.

Definition of Arctic:
noun: a geographical name of a large, extremely cold area around the North Pole;
My uncle is a scientist specializing in polar regions and he was five times in the Arctic already.
The glaciers in the Arctic are in big trouble because of climate changes.