Field Notes

<--2022-11-02 17:20:00 | 2022-11-30 09:50:00-->
Other sites visited today: Tonzi | Vaira

Hill Slough: 2022-11-17 09:35:00 (DOY 321)
Author: Daphne Szutu
Others: Joe

Summary: Regular data collection/cleaning, biofilms(?) on water surface, HMP fan broken--fixed

2022-11-17
Hill Slough

Joe and I arrived at 9:35 PST, stopping here on our way to Tonzi/Vaira. It was cool with high thin clouds and a little breeze. It was near high tide and the staff gauge read 4.58ft at 9:38 PST. The water was quite brown, not moving much, and had visible, glossy films (biofilms?) at the surface.

I downloaded met, cam, and USB GHG data. The GHG connection at the met box was working only intermittently, but I connected fine directly to the 7550 using a separate ethernet cable. The data all seemed fine. Joe cleaned flux and rad sensors. The HMP fan was broken so he replaced it with a new fan (12V). I changed the eddy clock +30sec from 9:55:15 to 9:55:45 and restarted logging. He topped off the wash reservoir.

I collected a water sample from the sipper to measure pore water conductivity later.

The 7500 read: 466ppm CO2 (seems high), 315mmol/m3 H2O, 11.5C, 102.8kPa, 101SS -- 102 after cleaning
The 7700 read: 2.34ppm CH4, 45RSSI – 71 after cleaning

At the channel, I collected miniDOT data and swapped its desiccant. There were a lot of shrimp clinging to the pantyhose on the bottom of the miniDOT; we rinsed them away. The pantyhose is still doing a great job prevent organisms from growing directly on the miniDOT though.

We also pulled up the EXO to check its cleanliness. A small fish plopped back into the water when Joe pulled the EXO out of the water—removing the bottom of the guard doesn’t seem to be enough to dissuade fish from hanging out inside the guard. There were some shrimp clinging to the sensors but the lenses were clean. The copper mesh is starting to wear away near the upper guard holes. I’m not sure if adjacent sensors are brushing against it occasionally, or if there’s some other physical/chemical degradation happening. During the next EXO cleaning/calibration, we could try copper tape inside and outside of the plastic guard instead of the copper mesh.

We left at 10:30 PST.

1 photos found

HS_picam_20221117_1715.jpg ( 2022-11-17 17:15:05 ) Full size: 1920x1442
Pretty sunset