Extreme Sea Ice Loss over the Arctic: An Analysis Based on Anomalous Moisture Transport

The Arctic system has experienced in recent times an extreme reduction in the extent of its sea ice. The years 2007 and 2012 in particular showed maxima in the loss of sea ice. It has been suggested that such a rapid decrease has important implications for climate not only over the system itself but also globally. Understanding the causes of this sea ice loss is key to analysing how future changes related to climate change can affect the Arctic system. For this purpose, we applied the Lagrangian FLEXible PARTicle dispersion (FLEXPART) model to study the anomalous transport of moisture for 2006/2007 and 2011/2012 in order to assess the implications for the sea ice. We used the model results to analyse the variation in the sources of moisture for the system (backward analysis), as well as how the moisture supply from these sources differs (forward analysis) during these years. The results indicate an anomalous transport of moisture for both years. However, the pattern differs between events, and the anomalous moisture supply varies both in intensity and spatial distribution for all sources.