Climatic Controls on Stream Flow in the McMurdo Dry Valleys

Large variations in meltwater generation (ave. 1.6 x 10⁶ m³, sd = 1.5 x 10⁶ m³) over the period of record of MCM LTER (1990 – 2012) have been observed.

This variation has importance to

• stream microbial communities: physical scouring of algal mats, nutrient availability (streams don’t always flow) and hydraulic forcing of hyporheic exchange rates
• lake microbial communities: transport of algal mats and nutrients (including water)
• glacier mass-balance measurements and interpretations of past closed-basin lake elevations Since its origination, the ozone hole has shown significant variability over the last two decades (Hassler et at., 2011).

Following the high flow season of 2001-2002, variability in meltwater generation appears to be de-coupled from temperature. Here we explore this de-coupling and propose a new driver, variations in the South Polar Ozone Hole.