The boundary layer response to recent Arctic sea ice loss and implications for high-latitude climate feedbacks

While near-surface temperature and humidity are minimally affected by sea ice loss in July 2007 forecasts, near-surface stability decreases and atmospheric humidity increases aloft over newly open water in September 2007 forecasts.

Ubiquitous low cloud increases over the newly ice-free Arctic Ocean are found in both the July 2007 and the September 2007 forecasts. In response to the 2007 sea ice loss, net surface [top of the atmosphere (TOA)] energy budgets change by +19.4 W m⁻ ² (+21.0 W m⁻ ²) and −17.9 W m⁻ ² (+1.4 W m⁻ ²) in the July 2007 and September 2007 forecasts, respectively. While many aspects of the forecasted response to sea ice loss are consistent with physical expectations and available observations, CAM4?s ubiquitous July 2007 cloud increases over newly open water are not.