Field Notes

Gilbert Tract: 2023-04-25 10:30:00 (DOY 115)
Author: Daphne Szutu
Others: Robert

Summary: Regular data collection/cleaning, SFSU field trip a few days ago, changed ADCP sampling duration/frequency from 60sec to 300sec

2023-04-25
Gilbert Tract

Robert and I arrived at 10:30 PDT. We left the lab a little later than usual because I had an ADCP meeting at 8:30. It was a lovely spring day, sunny and cool with occasional gusty breezes. Tules are definitely starting to come up. We also noticed a bit of duckweed among the azolla in the water. Birds were busy with their chitter chatter. I pulled 2 pepperweed plants just upslope from our tower.

Dennis, Robert, and Andrew Oliphant’s meteorology students from SFSU were here on Saturday for their annual field trip. Dennis said they enjoyed the boardwalk out into the water.

The staff gauge read 84cm at 9:40 PST.

Robert cleaned met and rad sensors and topped off the reservoir. He also took a walk out along the degraded road south of our tower.

I downloaded met, cam, and USB GHG data. I had some issues ejecting the USB because the LED started a slow blink when I pressed the eject button. However, there were no issues when plugging the USB into the laptop and the files seemed complete. I set the eddy clock +45seconds around 9:35 PDT to match the laptop time and reset the box. All seemed well.

The 7500 read: 422ppm CO2, 461mmol/m3 H2O, 21.1C, 101.3kPa, 107SS --> 107 after cleaning
The 7700 read: 2.04ppm CH4, 47RSSI –> 81 after cleaning

We arrived at the channel to download Flo’s data at 10:50 PDT. I see more dropouts starting to affect the data. We need to plan to come out at low tide next time to remove some aquatic vegetation, probably both banks. In the ADCP meeting this morning with Mark Stacey and his student Henry, they mentioned that the left beam is hitting the water surface at low tide and they recommend lowering the ADCP by about 50cm to prevent this problem and reduce noise. If we can’t move it 50cm, however much we move it would still help the problem.

I downloaded data, reset the clock so the ADCP matches the laptop time, and changed the sampling interval and duration from 60sec back to 300sec. I restarted data logging and checked that the live data looked ok. We had set it to 60sec last month at the request of Marc from Hydrofocus, but they have sufficient data now so I changed both the sampling interval and duration back to 300sec. I renamed the config files so they’re more descriptive:

“GT_20230323retreived.sontek_system_config” --> “GT_20230323_300sec.sontek_system_config”
“GT_20230323new.sontek_system_config” --> “GT_20230323_60sec.sontek_system_config”

We left around 11:10 PDT.

0 photos found

7 sets found

Can't check MBWPEESWGT_mixed
Can't check MBEEWPSWEPGT_cam
16 GT_met graphs found