FATE OF MERCURY IN THE ARCTIC Michael Evan ... - COGCI

Fate of Mercury in the Arctic 71
4.2 RGM concentrations and Flux
Figure 13., page 71, shows the result of the RGM measurements at Station Nord in 2002. The
measurements were made by manually sampling and using the improved heating caps, with
temperatures in the heating caps approximately 40 0 C, or some 80 0 C above ambient. Bar thickness
is proportional to exposure time. The thicker bars in the histogram were exposed more hours than
the thinner bars. Data is field blank corrected. The concentration varies between values below
detection limit and up to 75 ng m -3 . These values are comparable to those found at Barrow before
the start of strong AMDE’s (Lindberg et al. 2002) and very typical for calm weather conditions.
pg/m 3
Pg m-3
Figure 13. Manual RGM measurements made during April,2002 at Station Nord
80.00 80
70.00 70
60.00 60
50.00 50
40.00 40
30.00 30
20.00 20
10.00 10
0.00 0
7-apr 9-apr 11-apr 13-apr 15-apr 17-apr 19-apr 21-apr 23-apr 25-a
Time Date
The relaxed eddy accumulation system operating at 10 m above the tree top canopy on the
tower at Walker Branch Research Area, Oak Ridge showed no mass uptake in the up or down tubes
operating at 10 Hz; n = 3. The frequency was adjusted to 1 Hz and the measurable flux; n=3; 1 Hz