Field Notes

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Other sites visited today: Hill Slough | East End | Mayberry | Gilbert Tract
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West Pond: 2023-06-15 12:00:00 (DOY 166)
Author: Daphne Szutu
Others: Robert

Summary: Regular data collection/cleaning, 7700 calibration, reset 7700 cleaning/heating settings, improved the power cable, lots of ants/ant eggs in met box

2023-06-15
West Pond

Robert and I arrived around 12:00 PDT. It took almost two hours to get here from Hill Slough because the Rio Vista bridge was under one-way control. It was breezy, warm, and partly overcast with cirrus clouds. There were lots of ants and ant eggs in the met box. I also found my gloves in the met box! Luckily they didn’t seem to have too many ants or eggs in the gloves. I left them some mothballs at the end.
A worker passed by with a chainsaw, clearing branches, on the interior levee road north of us.

We started first by improving the power cable. The power cable has two segements, one that runs from the tower to the road, and the second that runs under the road to the solar panels/batteries. Two weeks ago we had fixed the power temporarily by attaching the two segments via a pluggable screw terminal and then wrapping up the power strip with electrical tape. When we arrived the screw terminal had come apart regardless of the electrical tape. We lost data two days ago on 2023-06-13.

I turned the power off at the solar power controller and Robert removed the pluggable screw terminal and threaded the power cable through a few pieces of conduit to protect it from getting eaten by the willow and maybe protect it from mowers. Two pieces of conduit are running parallel to the road and one piece is perpendicular to the road between the tower and the road. Robert covered the 90-degree turn with aluminum tape. He reconnected the cable with two wire nuts and squirted in a bunch of silicone dielectric grease. We left the ground wires disconnected.

I disconnected the incoming power from the met box and went back out to the charge controller to turn the power back on. Robert measured 0V at the met box, so I turned the charge controller off again. The wire nuts seemed secure, but Robert re-did the connection with slightly less grease in case there was so much grease the first time that it was hampering the connection. I turned the power on again and Robert realized he should be measuring DC voltage instead of AC voltage. He measured about 24V at the tower, so I left some mothballs in the battery box for the ants and closed everything up again. I’m not sure if the problem the first time was the wire nuts or the voltmeter setting.

After the power was on, I downloaded met, cam, USB GHG, and miniDOT data. I swapped the miniDOT and water level desiccant. The staff gauge read 59cm. Robert cleaned flux and rad sensors. I don’t remember if we topped off the wash reservoir.

We did the 7700 calibration. The heating and cleaning settings were on default when we arrived—maybe its brains got scrambled with the recent power outages? I updated the settings to what I remember as our usual settings. The zero was right on and the span had a small offset. The optics RH=13%, so we did not flush its headspace or change the desiccant afterwards.

The 7500 read: 413ppm CO2, 695mmol/m3 H2O, 26.8C, 101.1kPa, 96SS--101 after cleaning
The 7700 read: 1.99ppm CH4, 39RSSI--89 after cleaning

We left at 13:25 PDT.

Looking at the data back in the lab, NDVI 650in and 810in seems too high after the recent power outages. Maybe it just needs to be power cycled next time. This is the older Decagon sensor that has been installed since 2017.

2 photos found

20230615WP_PowerConduit.jpg ( 2023-06-15 13:25:21 ) Full size: 1440x1920
Power cable has now been threaded through conduit to protect it from the willow growing and trapping it.

20230615WP_WireNuts.jpg ( 2023-06-15 13:25:33 ) Full size: 1440x1920
New wire nuts (and silicone dieletric "goop") for the power cable to connect the piece that comes from the tower and the piece that comes from underground.