Melting Arctic sea ice has contributed considerably more to warming at the top of the world than previously predicted by climate models, according to a new analysis of 30 years of satellite observations.
Sea ice helps cool the Arctic by reflecting incoming solar radiation back into space. Because of its light color, sea ice has what is known as high albedo, which is the percentage of solar radiation a surface reflects back to space. Dark ocean water left behind by melting sea ice, on the other hand, has a low albedo, usually measuring less than 20 percent, whereas bare sea ice generally measures between 50 and 70 percent, according to the National Snow and Ice Data Center.
Since as early as the 1960s, scientists have hypothesized that melting sea ice amplifies global warming by decreasing Arctic albedo. Researchers have since devised climate models to demonstrate this phenomenon but, until now, nobody had relied entirely on satellite data to confirm this effect through time. [See Stunning Photos of Earth's Vanishing Ice]
The taste of September across the north-central United States will give way to a resurgence of heat, steamy air and severe weather by midweek.
Much cooler air with temperatures more typical of mid- to late September will sweep across the Great Lakes and Northeast early this week.
Residents of the northeastern and midwestern United States should not get used to the September-like air pouring in early this week.
The recent April-like rainy stretch of weather will quickly get erased by a resurgence of sizzling heat in northeastern China this week.
Despite escaping the worst of newly-formed Tropical Storm Dora, southern Mexico will still face locally flooding downpours and rough seas into Monday.
Much of the southern United States dealing with the aftermath of Cindy will get a break from hot, humid and stormy conditions by the end of the weekend.