Boreal and Northbound

Boreal adjective - Toward or located in the north.

Northbound and boreal are semantically related In some cases you can use "Northbound" instead an adverb "Boreal".

Northbound adjective - Moving toward the north.

Boreal and northbound are semantically related in toward the top pole of the earth topic. You can use "Boreal" instead an adverb "Northbound".