The significant decline of Arctic sea ice under global warming

especially in summer

plays an important role in global and regional climate change

and affects global and regional ecosystems. Here

the spatio-temporal variations of Arctic sea ice and their causes were analyzed based on satellite microwave AMSR-E data for June 2002 through February 2011. The results showed that the extent of Arctic sea ice decreased by 82800 km2 annually

decreasing most rapidly in summer. The rate of decrease in summer for the period 2002—2011 was more than twice that of 1979—2006; moreover

sea ice concentration also decreased. The sea ice conditions were heavy in 2003 and 2004

while 2007 experienced a minimal sea ice area. Perennial sea ice decreased approximately 30% between 2002 and 2011 with decreases occurring in the Beaufort Sea

Chukchi Sea

East Siberian Sea

Laptev Sea

Kara Sea

and over the vast area from these marginal seas to the Arctic Ocean. Increases in seasonal sea ice occurred in regions where perennial sea ice decreased. The sea ice area has a significant negative relationship with the annual average temperature

and the decrease trend will continue with global warming intensification.