What is surface mass balance?

What is surface mass balance, how do we calculate it and why is it important? This is a video that has come out of a collaboration between two Horizon Europe (EU science programme) funded projects PolarRES and OCEAN:ICE. The video series: “Explain it in Two Ways” In this second episode Ruth Mottram, project coordinator of OCEANICE and participant in PolarRES, explains what surface mass balance means, and its importance in Polar research. This is the general knowledge version, have a look at the technical version and see which makes most sense to you!