Annual Arctic sea ice less reflective than old ice

May 17, 2012

In the Arctic Ocean, the blanket of permanent sea ice is being progressively replaced by a transient winter cover. In recent years the extent of the northern ocean's ice cover has declined. The summer melt season is starting earlier, the winter freeze is happening later, the areal extent of the ice has decreased, and more ice is failing to last through the summer.

A key uncertainty in this ongoing climate transformation is how seasonal affects and responds to as compared to the traditional multiyear sea ice. Tackling an important branch of this issue, Perovich and Polashenski analyze how the albedo of seasonal sea ice changes throughout the summer melt season. The ice's albedo affects how much sunlight enters the system and hence influences , ice extent, and future rates of warming.

For four years, the authors measured the albedo every 2.5 meters (8 feet) along a 200-m (656-ft) stretch of seasonal ice off the northern coast of Alaska. They find that though the albedo of snow-covered winter seasonal ice is the same as that of multiyear ice, the equivalence fades rapidly with the summer thaw. They find that seasonal sea ice albedos experience seven distinct phases: cold snow, melting snow, pond formation, pond drainage, pond evolution, open water, and refreezing. Though the albedos of seasonal and multiyear ice experience similar transitions, the rate and extent for the two types of ice vary drastically with the potential for a large effect on the Arctic Ocean . The authors find that over the course of one melt season nearly 40 percent more energy would enter an ocean system with seasonal sea ice cover than one with multiyear ice.

Explore further: TRMM satellite sees Tropical Storm Phanfone fragmented

More information: Albedo evolution of seasonal Arctic sea ice, Geophysical Research Letters, doi:10.1029/2012GL051432 , 2012

add to favorites email to friend print save as pdf

Related Stories

Declining sea ice to lead to cloudier Arctic: study

Mar 31, 2012

Arctic sea ice has been declining over the past several decades as global climate has warmed. In fact, sea ice has declined more quickly than many models predicted, indicating that climate models may not be correctly representing ...

NASA Sees Rapid Changes in Arctic Sea Ice

Sep 13, 2006

NASA data shows that Arctic perennial sea ice, which normally survives the summer melt season and remains year-round, shrunk abruptly by 14 percent between 2004 and 2005. According to researchers, the loss of perennial ice ...

Winter Sea Ice Fails to Recover, Down to Record Low

Apr 06, 2006

Scientists at NSIDC announced that March 2006 shows the lowest Arctic winter sea ice extent since the beginning of the satellite record in 1979 (see Figures 1 and 2). Sea ice extent, or the area of ocean that ...

Recommended for you

Sculpting tropical peaks

4 hours ago

Tropical mountain ranges erode quickly, as heavy year-round rains feed raging rivers and trigger huge, fast-moving landslides. Rapid erosion produces rugged terrain, with steep rivers running through deep ...

Volcano expert comments on Japan eruption

5 hours ago

Loÿc Vanderkluysen, PhD, who recently joined Drexel as an assistant professor in Department of Biodiversity, Earth and Environmental Science in the College of Arts and Sciences, returned Friday from fieldwork ...

NASA's HS3 looks Hurricane Edouard in the eye

17 hours ago

NASA and NOAA scientists participating in NASA's Hurricane and Severe Storms Sentinel (HS3) mission used their expert skills, combined with a bit of serendipity on Sept. 17, 2014, to guide the remotely piloted ...

User comments : 0