Goodbye, summer. See you soon, research!

In less than 24 hours, I packed up my dorm room, worked my last summer day, gave my final presentation, and returned back home to Chicago.  Summer in Williamsburg has sadly come to close, but my research is far from conclusion.  While time away has been relaxing, having nothing to do on the rainy days is hard to get used to, and I am anxious to get back in my lab!

I ended the summer with sodium-22 (and pb-210 and be-7) data for February, March/April, May, and June.  Not too shabby!  Average volume weighted 22Na concentrations were 0.180 ± 0.041, 0.150 ± 0.025, 0.177 ± 0.031, and 0.200  ± 0.040 mBq/L respectively (with+/-95% confidence intervals).

These findings indicate that the average monthly dissolved 22Na in precipitation is relatively consistent.  By using mean 22Na concentrations in precipitation and assuming steady-state behavior of sodium, we were able to assess stream water age in Pagonia stream, a forested river in the College Creek Watershed that drains non-calcareous sandy sediments.  22Na concentrations in this small watershed (16 hectare) measured in June 2012 were less than the detection limit (0.072 mBq/L), suggesting a minimum age of 3.38 years.

However, in order to learn more about the water age of the Pagonia stream water, I need to do future research on the variables that affect 22Na concentrations in stream water, most prominently evapotranspiration and the travel time of a water molecule through the watershed.  Oh, and how could I forget…I’ll need to collect more water!

More to come in the fall!!