Arctic ice is building up after a long cycle of decline. These major temperature cycles only affect the Northern Hemisphere. Antarctica was never bothered by it. So, hot on the heels of "Wavy Jet Stream", we have 'New ice causes new ice build-up'.
I love these things.
ps. I was just thinking that the brilliant young things that designed the balloon would have said "Why don't we have sensors pointing down so we can directly observe "The Great Greenhouse Effect". And nasa would have said "Shut up or we'll kill you."