Expanding observations of mixing in Toolik Lake with the North American Regional Reanalysis

The ecology of Toolik lake depends ultimately on the the properties which govern nutrients, light and primary production. Among these influences is the relationship between temperature and mixing within the lake. Recent research has demonstrated linkages between long term variation in lake temperature and synoptic scale climate. (MacIntyre et al. 2009) shows that interannual variation in the number of storm events correlates with epilimnion temperature.  Storm events, characterized by strong winds and, most importantly, significant drops in air temperature, drive mixing and govern the balance between the development of a warm and stable surface layer and the deep mixing of nutrients.  A significant relationship between the lake temperature at Toolik and a count of storm events suggests that synoptic scale counts of storm events may be used to predict temperatures, and thus mixing or stability at lakes across large spatial scales. This analysis employs the National Center for Environmental Prediction’s North American Regional Reanalysis (NARR) as the source of synoptic scale climate measurements. The analysis first investigates the validity of the NARR data at Toolik, then uses the NARR to look at climactic variability in Alaska and northern Canada. We use variance in a frequency band as an indicator of storm events. With an improved proxy applied to NARR data, it may be possible to describe climactic effects on lake in much of the North American Arctic.