Field Notes

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Other sites visited today: Mayberry | West Pond

East End: 2023-01-18 15:20:00 (DOY 18)
Author: Daphne Szutu
Others: Joe, Robert

Summary: Regular data collection/cleaning, inspected power system, raised solar panels up above the tules, calibrate 7700, dfPAR not working--more work needed, leaky 7700 reservoir--fixed?, NDVI data bad--needs more work

2023-01-18
East End

Joe, Robert, and I arrived at 15:20 PST. It was overcast, cool, and breezy. The staff gauge read 48cm. Most of the wetland is brown but there is one tule type (triangular cross section) that senesces more slowly. Bunches of it by the road are still green and “definitely alive.” Today was for maintenance and for regular data collection. We checked the power system and calibrated the 7700.

This site has been losing power and the solar panels are now lower than the tops of the surrounding tules. We swapped the tower power to a spare car battery we brought with us and Joe and Robert worked on adding a half layer of scaffolding to the solar system. They were able to carefully unmount the solar panels, add the new frames under the panels and then lift and remount the panels on top of the new frames. Joe disconnected and isolated the four sealed batteries. They all tested good with the load tester. The batteries are not in a box and look rather worn. With the solar panels being higher the batteries now have even less shelter. We will get an action packer box to protect them more. The screw terminals on the solar controller were all tight.

We calibrated the 7700. Both the zero and span offsets were small. The optics RH was 21%, so after the calibration I flushed the headspace with zero air until the optics RH was 14%. I swapped the desiccant and replaced the spiky hat and the spray nozzle afterwards.

The reservoir was empty today and had been empty the last couple of times, so I pulled the tank out to look at the in-line filter. Lots of wasps in the box that I dumped out. We’ve had problems with the in-line filter leaking in the past. Today the filter had a greenish tint, so I swapped the filter. I refilled the reservoir, mounted it back on the scaffolding, and tested the spray/spin. The spray/spin was fine but there was a small leak in the tubing inside the enclosure. I snipped off the leaky section and repaired it. Maybe this tubing has been rotting in the sun over the summer when we leave the lid open to discourage wasps. We could swap it for the black tubing that is more UV resistant. Not sure if the tubing or the in-line filter (or something else) was the bigger problem.

Robert cleaned flux and rad sensors. I downloaded met, cam, and USB GHG data. I checked the conductivity sensor as part of its routine check every 3 months and the orifice looked clean.

The rotating shadowband was not working. Robert tried to start it manually but it wasn’t turning, so we probably need to replace the motor. We used our spare motor earlier today at GT, so this needs to wait until next time. I don’t remember if there was water in the dfPAR enclosure, but probably.

NDVI data has also been weird here. There are a bunch of gaps from the power outages but data never restarted after the most recent outage. I forgot to look at it more before we left. Next time.

After Joe and Robert finished their work on the solar system, we removed the tower from the spare car battery and hooked it back up to the solar system.

The 7500 read: 425 ppm CO2, 462mmol/m3 H2O, 12.8C, 102kPa, 99SS – 100 after cleaning
The 7700 read: 2.3ppm CH4, 36SS – 79 after cleaning

We left at 17:05 PST.

1 photos found

20230118EE_SolarWork.jpg ( 2023-01-18 16:24:05 ) Full size: 1920x1440
Robert and Joe installing a half layer of scaffolding to lift solar panels above tule canopy