Borealis Blades

The ground around you in a 30-foot-radius Circle sprouts blades of blue ice that glimmer with dancing green lights. The area becomes Difficult Terrain for 1 minute. Each creature in the area except you takes 3d6 Cold damage and 3d6 Piercing damage and has its speed reduced by 10 feet for 1 round.

Using a higher level spell slot. Both the Cold and Piercing damage increase by 1d6 and the radius of the circle increases by 5 feet for each slot level above 5th.  When using a 8th or 9th level spell slot, The cold damage is instead 10 times the spell slot level.