Arctic sea ice, the vast sheath of frozen seawater floating on the Arctic Ocean and its neighboring seas, has been hit with a double whammy over the past decades: as its extent shrunk, the oldest and thickest ice has either thinned or melted away, leaving the sea ice cap more vulnerable to the warming ocean and atmosphere.\u201cWhat we\u2019ve seen over the years is that the older ice is disappearing,\u201d said Walt Meier, a sea ice researcher at NASA\u2019s Goddard Space Flight Center in Greenbelt, Maryland. \u201cThis older, thicker ice is like the bulwark of sea ice: a warm summer will melt all the young, thin ice away but it can\u2019t completely get rid of the older ice. But this older ice is becoming weaker because there\u2019s less of it and the remaining old ice is more broken up and thinner, so that bulwark is not as good as it used to be.\u201d<\/p>\n","protected":false},"author":0,"featured_media":0,"template":"","meta":{"_acf_changed":false,"footnotes":"","_links_to":"","_links_to_target":""},"class_list":["post-2180695","news","type-news","status-publish","hentry"],"acf":[],"yoast_head":"\n