资源环境科技发展态势分析平台

The recent dramatic decline of sea ice in the western Arctic Ocean changes the transfer of momentum across the ice-ocean boundary layer. The surface stress energy input through the surface geostrophic current in the Beaufort Gyre (BG) based on a numerical model is 0.03 mW/m(2) in 1992-2004 versus 0.23 mW/m(2) in 2005-2017. This energy input is primarily concentrated over the southern Canada Basin and the Chukchi Sea. It is 1.38 x 10(16) J in observations versus 4.90 x 10(16) J in the model in the BG during 2003-2014. We find that some well-known freshwater changes in the BG over 1992-2017 resulted from episodic extrema of energy input in 2007, 2012, and 2016. In particular, most of the energy input in 2007 was transformed into potential energy (57%) which resulted in a new state of freshwater budget. Our study suggests that as of 2016, the BG had not yet reached a saturated freshwater state. Our results provide a way to predict the future changes of BG freshwater content.