September 2018 also ties with September 2008 for the sixth lowest September in the satellite record.

Arctic sea ice has likely reached its 2018 annual minimum, dropping to 4.59 million square kilometers on September 19 and 23. Tied with 2008 and 2010, it is the sixth-lowest minimum in the nearly 40-year satellite record.

 Tiny valleys near the top of Antarctica’s ice sheet reach temperatures of nearly -100 degrees Celsius (-148 degrees Fahrenheit) in the winter.

NSIDC senior research scientist Ted Scambos co-authors the Nature paper, which breaks new ground in implicating sea ice change in sea level rise.