Field Notes

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Other sites visited today: Mayberry | East End | West Pond | Hill Slough

Gilbert Tract: 2024-02-12 10:05:00 (DOY 43)
Author: Daphne Szutu
Others: Kyle

Summary: Lots of litter blown down from storms, swapped 7500 for calibration, ADCP cable cut/chewed--fixed

2024-02-12
Gilbert Tract

Kyle and I arrived at 10:05 PST. It was a calm and cool day, overcast with thin clouds. There have been several storms since our last visit, so last year’s litter has been blown down by at least a meter. One of the shrubs (mule fat?) on our usual path has also blown over and we have to duck under it.

There are some green tules coming up along the edges of the marsh where the cattail were trimmed back.

The water level was ebbing and the ground was mushy under the tower. The armored power cable between the solar scaffolding and the sensor scaffolding seemed to be drooping lower—maybe it was just held up by all of the tall reeds before? I didn’t see any power interruptions in the data.

The staff gauge read 59cm at 10:43 PST. Kyle measured the conductivity of the surface water off of the boardwalk pier.

Sample, Temperature-compensated conductivity, Temperature
Surface, 472 uS, 9.0 degC

We moved the upper boardwalk back up (it had been moved lower down for storm prep) and left it there since there don’t seem to be any crazy winds in the current forecast. I replaced our substitute turnbuckle (u-bolt + carabiner) with an actual turnbuckle for the northwest fence post.

The reservoir was empty; Kyle refilled it. I downloaded met, cam, and USB GHG data. Kyle cleaned flux and rad sensors. We swapped the LI-7500 for calibration: sn 75H-2176 came off and sn 0418 went on. I uploaded a new configuration file, updated the pressure coefficients, reset the clock +45sec from 10:31 to 10:31:45 to match the laptop time, and restarted logging.

75H-2176 dirty read: 443ppm CO2, 458mmol/m3 H2O, 12.0C, 102.2kPa, 100SS
75H-0418 fresh read: 443ppm CO2, 445mmol/m3 H2O, 12.6C, 102.4kPa, 100SS
The 7700 read: 2.3ppm CH4, 20RSSI – 82 after cleaning

We went to the channel to download Flo’s data at 10:50 PST. I couldn’t connect to Flo, even after cycling its power. There was a lot of condensation dripping off the ceiling of the enclosure box—I wiped it off and thought maybe the charge controller had gotten really wet. I took the controller cover off, and it all looked fine. Kyle noticed that one of the cables outside of the box had been cut—bingo. It was the ADCP cable! It looked like a relatively clean cut, so maybe it was accidentally nicked with a landscaping tool. There was plenty of slack in the cable, so Kyle stripped back the cable and wired it to the terminal block. I plugged it in, connected to the ADCP, and downloaded data. The last data was from 2024-02-02 05:00. I stopped and restarted data logging so a new file is created.

We left at 11:40 PST.

6 photos found

20240212GT_Blowdown.jpg ( 2024-02-12 10:47:07 ) Full size: 1920x1440
A lot of blowdown from the storm on February 3-4, new tules coming up through the previously trimmed cattail

20240212GT_HackTurnbuckle.jpg ( 2024-02-12 10:13:29 ) Full size: 1440x1920
When the turnbuckle broke during the previous site visit, we created tension between the chain and the fence post using a long u-bolt and a carabiner

20240212GT_TreeDamage.jpg ( 2024-02-12 10:51:23 ) Full size: 1920x1440
Large tree branch down by the mouth of Little Dutch Slough, probably from the windy storm on February 3-4

20240212GT_Turnbuckle.jpg ( 2024-02-12 10:46:18 ) Full size: 1440x1920
Today we replaced our hacked-together connector with a real turnbuckle. Next time I should loosen up the bolts more before tightening it down. Now there's not much more tightening that can be done before it needs to be reset.