Field Notes

West Pond: 2013-08-21 10:40:00 (DOY 233)
Author: Cove Sturtevant
Others: Joe, Laurie

Summary: East pond water low. Calibrated 7700. Swapped out 7500 and 7550. Moved 7550 location to top scaffold tier. Replaced broken shield for 7700 thermocouple. Updated 7700 time to GMT+8.

West Pond
2013-08-21

We arrived around 10:40 PDT. It was sunny, breezy, and cool (20 C).

The inlet was running and the water under the tower was normal, although the East Pond water level was very low. Laurie went to grab water samples while Joe and I attended to the tower, calibrated the 7700, and swapped out the 7500 and 7550 box (removed 7550 s/n 0666 and 7500 s/n 2176, installed 7550 s/n 0614 and 7500 s/n 2182).

I opened the 7550 box and the ant activity was very low. But then I poked one of the foam seals and they came streaming out, so I think they were just dormant inside the box. Hopefully that means we removed the whole population and they wont just recolonize the new 7550 box we brought out. We installed the new 7550 box on the second scaffold tier to place it farther from curious insects. The ant-infested box is currently undergoing a nitrogen bath in the lab (sorry anties!).

7500 readings (before swap):
CO2 = 395 ppm
H2O = 650 mmol m-3
signal strength = 87.3%
t = 20.9 C
p = 100.9 kPa
sos = 345.6 m s-1

7500 readings (after swap):
CO2 = 392 ppm
H2O = 650 mmol m-3
signal strength = 83.8%
t = 21.2 C
p = 101.1 kPa
sos = 346.4 m s-1

7700 readings:
CH4 = 1.89 ppm (same after cleaning)
RSSI = 60 (86 after cleaning)
Reservoir was full.
We replaced the broken shield for the 7700 thermocouple with some shrink tubing of approximately the same diameter.

MET looked good.

We calibrated the 7700 with zero gas and 4.995 ppm span tanks we brought with us. The zero offset was 0.01 ppm and the span offset was 0.013 ppm. CH4 read 1.92 ppm after calibration. We downloaded the GHG data because we noticed the 7700 time was not updated to GMT+8 (was still in GMT-8, causing the heaters to come on at the wrong times). I dont think this had any effect on the data sync to the 7550, but we downloaded the data anyway and changed to the correct GMT+8 time zone.

1 photos found

WP_autocam_20130821_1015.jpg ( 2013-08-21 10:15:02 ) Full size: 1920x1440
Calibrating 7700