Arctic mean EPℓCg as a function of spatial scales ℓ for 2012–2015 (cyan) and 2092–2095 (orange). Its value at the scale ℓ indicates the surface kinetic energy input on all scales smaller than ℓ . The solid lines and the dashed lines represent the results for February to May and for August to November, respectively. The dots show the positions of minimum EPℓCg.
