Field Notes

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Hill Slough: 2024-07-16 14:00:00 (DOY 198)
Author: Daphne Szutu
Others: Irene

Summary: Windy!, Swapped 7500 for calibration, removed EXO for calibration, 7700 thermocouple broken, new channel CR23X datalogger program that sends all data to tower CR1000, raised height of water channel sensors

2024-07-16
Hill Slough

Irene and I arrived around 14:00 PST (15:00 PDT). It was super windy! It was sunny and warm but the cool wind made it feel mild. There was some small bunches of tules visible along the boardwalk. The staff gauge read 4.6ft at 14:12 PST.

I downloaded met, cam, and USB GHG data. We swapped the 7500A for calibration: sn 0035 came off and sn 0042 went on. I uploaded the new config file and updated the pressure coefficients. I reset the 7550 box and noticed that there was a 7700 time sync error. I changed the eddy clock +30sec from 14:30 to 14:30:30 to match the laptop time, restarted logging (I think), and confirmed that the 7700 was ok.

The reservoir was almost empty again. I checked the spray and spin, and all seems well. Looking at the data, the RSSI was fluctuating between 30-50 over the last few weeks. I should check the wash settings again. We refilled the reservoir.

The 7700 thermocouple was broken. The density data is fine. I’ll bring a replacement next time. The 7700s are due for calibration anyways—good luck finding a calm day here!

We measured the porewater and surface water conductivity at the tower. They were very similar today (surface water was more similar to usual porewater).

Sample, Temperature-compensated conductivity, Temperature
Porewater, 6.62mS, 23.9C
Surface, 6.45mS, 24.8C

old 0035 read: 399ppm CO2, 702mmol/m3 H2O, 24.7C, 101.6kPa, 90SS—97 after cleaning
fresh 0042 read: 414ppm CO2, 572mmol/m3 H2O, 24.6C, 101.6kPa, 99SS
7700 read: 0.08 mmol/m3 CH4, 40RSSI – 86 after cleaning

At the channel, I downloaded the CR23X data (need it fill in missing CTD conductivity data not getting sent to the CR1000). I sent a new CR23X program that will send all of its data to the CR1000. I checked the CR1000 real-time data and confirmed that the CTD conductivity data showed up.

The eosGP has had a maxed out pCO2 value for a while. Turns out both it and the CTD were stuck in the mud. It was like pulling a weed--some resistance while the root/sensor comes out of the soil, then suddenly out it plops. We raised both sensors by about 30cm. Another height offset for the Hill Slough water level... yay.

We downloaded the miniDOT data and swapped its desiccant. The miniDOT didn't seem to be in the mud so I left it at its current height.

We removed the EXO for its routine quarterly calibration. The pH/ORP module also needs to be swapped.

Sensors removed:
sn 22C103416 EXO2
sn 22E106072 Turbidity
sn 22E100649 fDOM
sn 23D104030 Conductivity/Temperature
sn 22D102641 pH/ORP

We left around 15:00 PST (16:00 PDT). I originally planned to calibrate the EXO this afternoon in the lab and deploy it tomorrow with the second part of our Delta servicing, but today took longer than I anticipated. We'll be back next week to deploy the EXO. Spring tide is next week and Irene wants to come back to re-do some of the soil sampling GPS points. Spring tide will also be a good chance to adjust the height of the water channel sensors, if needed.

0 photos found

4 sets found

21 HS_met graphs found