"One meter" describes the peak height (skier to ground) of the jump.
We don't know how far the skier travelled horizontally in the air before coming down again (but presumably she did travel horizontally after going over a bump!). However, you can also use this expression for going straight up, with no horizontal movement, if the context makes sense.
Some other prepositions can fit in this context. "In the air" would mean the same thing. As @SteveES suggests in his comment, either of these can be and often is preceded by "up" to emphasize the height. On the other hand, "through the air" would tell you the horizontal distance instead.
Here are some examples:
"Sand flea robot can jump 30 feet in the air" (source)
"A kid jumps a meter into the air. How long before he lands?" (source)
"This little robot can jump three feet in the air" (source)
Here's an example of "through the air" indicating the horizontal distance:
"[A]thletic dog jumps 20 feet through the air" (source)