Description
Summary:ˆ The North Pacific atmosphere-ocean system reflected a combination of a response to La Niña and intrisic variability. The combination of the neutral to weak El Niño expected this winter and a continuation of reduced ice cover in the central Arctic should yield a lighter ice year for the Bering in 2013. ˆ Ocean temperatures remained cold and sea ice remained extensive, similar to 2008 and 2010. Ice retreat this year (and 2009) was the latest recorded since 1985. Summer was calm and cool, but had the most extensive cold pool area of the recent decade. ˆ The summer Calanus copepod time series showed an increase in abundance in 2011 relative to 2010, but remained below the 2009 peak. 2011 was the fourth year that concentrations remained well above average, following patterns also seen in fall zooplankton abundance during cold years. This suggests that prey availability for planktivorous fish, seabirds, and mammals continued to be high during the summer of 2011. ˆ Jellyfish remain abundant, although peak abundances observed in fall 2010 and summer 2011 declined by fall 2011 and summer 2012.