Field Notes

<--2023-01-06 16:30:00 | 2023-02-01 11:10:00-->
Other sites visited today: West Pond | East End

Mayberry: 2023-01-18 10:20:00 (DOY 18)
Author: Daphne Szutu
Others: Joe, Robert

Summary: Regular data collection/cleaning, swapped power line, calibrate 7700, swap 7500 for calibration, replace two thermocouple profiles, dfPAR not working--replaced motor, NDVI sensors bad--removed

2023-01-18
Mayberry

Joe, Robert, and I arrived at 10:20 PST. It was sunny and cool with scattered low clouds. There were dozens of cormorants and other birds in the water by the gas line. Probably some good fish in that area. The floating white platform (some sort of antenna/receiver?) in the channel was not there today.

Today was for maintenance and for regular data collection. We replaced the power line, calibrated the 7700, swapped the 7500 for calibration, and replaced two thermocouple profiles.

The staff gauge read 63cm. The floating boom had blown to the west; I pushed it back to point north.

We disconnected the power at the tower and powered it temporarily with a car battery we brought while Joe replaced the power line from the solar system to the power. He pulled the old 14 gauge direct burial wire from the conduit and replaced it with a piece of Patty's armored 10gage wire left over from Sherman. All the gaps in the conduit are fixed and very little of the wire is exposed. We returned the tower to solar power and all seemed well.

I downloaded met, cam, and USB GHG data. Robert cleaned flux and rad sensors. I forgot to check the wash reservoir, but the spray was fine, so there was at least some water left in the reservoir.

The Mayberry pi-cam might be running the old program without compression. The downloaded zip file was large, about 1GB for the past two weeks, and the zip files from other cameras were <200Mb., something to check next time.

The Decagon NDVI sensors haven't been producing numbers since the power line broke in late December. I couldn't talk to either sensor using the Terminal Emulator. Both of the sensors are spliced, and one of the splices had a loose heatshrink and dampness inside the heatshrink. The other splice had secure heatshrink. I removed both sensors sn 2046503354 and sn 2046503376 to bring back to the lab for further testing.

We calibrated the 7700. Offsets for zero and span were both small. The optics RH was 15%, so I did not flush headspace with zero air or change desiccant. We replaced the spiky hat and the spray nozzle afterwards. We tested the spray and spin afterwards.

We swapped the 7500 for calibration: sn 75H-2514 came off and sn 0035 went on. I uploaded a new config file, update the pressure coefficients, and reset the 7550 box. The eddy clock looked ok, so I did not reset it. All looked ok.

The rotating shadow band has worked only rarely since early January. Robert replaced the motor. There was some water in the dfPAR enclosure that he wiped away. Might add some putty to the holes next time. The picam had gotten jiggled while fixing the dfPAR; we releveled it.

We replaced two of the thermocouple profiles. The one out in the main channel was pulled and the new one only reached about halfway to the original location. It went in about 3m NEE of the tower in waist deep water where some sparse cattails were poking up but not part of the main vegetation - yet. The other one was in the cattails to the west of the tower. Here too the replacement only made it about half of the way to the original location and went in some cattails near the northwest corner of the scaffolding, about 0.5m NE of the corner. Both were pushed about 32cm into the soil, measurement locations at +100cm, +50cm, +30cm, +10cm, 0cm, -8cm, -16cm, -32cm. They were wired from highest location (+100cm) to lowest location (-32cm), but after looking at my notes back in the lab they were originally wired in the other way, from lowest location to highest. I’ll change the wiring next time and manually adjust the current data.
We were still seeing some bad readings (NaN or bad data) on the TCs/ We tested continuity on one of the new TCs and it was fine. We think the AM25T mux might have some bad channels. I think there is a spare in the lad we can swap in next time.

Joe gathered up some conduit and posts from the ground exposed by the recent goat grazing and stored them under the solar panels.

2514 dirty read: 460ppm CO2, 414mmol/m3 H2O, 8.7C, 101.7kPa, 102SS
2514 clean read: 468ppm CO2, 390mmol/m3 H2O, 10.9C, 101.7kPa, 103SS
0035 fresh read: 460ppm CO2, 372mmol/m3 H2O, 11.9C, 101.6kPa, 101SS
The 7700 read: 3.8ppm CH4, 39RSSI --> 85 after cleaning

We left at 12:45 PST.

0 photos found

11 sets found

7 MB_flux graphs found