Field Notes

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Other sites visited today: East End | Bouldin Alfalfa | Bouldin Corn
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West Pond: 2020-05-19 13:15:00 (DOY 140)
Author: Daphne Szutu
Others: Joe, Ariane

Summary: Regular data collection/cleaning, peat core collection, 7700 calibration, swapped 7500 for calibration, installed miniDOT, cleaned conductivity sensor. Ariane - soil core

2020-05-19
West Pond

Joe and I arrived at 13:15 PDT. It was warm, breezy, and partly cloudy with large cumulus clouds. The wetland is about half green, and the tules across the road in East Pond are seeding. Large thistles were bordering the dirt roads around the wetland; Joe dug a few by the tower up. There were goats on the dirt roads surrounding East Pond. The water level was 34 cm.

Ariane has been here since morning, taking samples with the new peat corer. Ariane: I took two cores at the 0.5 footprint with the Wardenaar peat corer. The purpose of these news cores was to avoid soil compaction and get more accurate estimates of soil accretion rates (cm yr-1) at WP. The Wardenaar corer is very sharp at the bottom, but it is heavy and not straight forward to manipulate. I needed help from Joe and a hammer to push the corer into the peat at about 60 cm. Evn thhough the sharp edges, surface layers were still experiencing some compaction, therefore I ended up cutting with a knife the upper 20 cm section before using the Wardenaar. The upper 60 cm were very fibrous and a clayey section was reached below this depth. The Wardenaar came with a missing part - the thin tube + hand pump to vent the soil core and unplug it before extruding the corer. Need to reach out to claim these parts.

We calibrated the 7700 sn TG1-0224. The offsets were small. We also swap the 7500 for calibration: sn 0418 came off and sn 0041 went on. I sent a new configuration file, updated the pressure coefficients, and reset the 7550 box. There was a clock sync error, and another 7550 box reset solved the error. I confirmed the 7700 was connected and the USB was logging.

I downloaded met, cam, and USB GHG data. The eosGP sensor still has a maxed-out CO2 reading since itâ€™s been underwater. There were a lot of dead ants in the datalogger box from last time; I added fresh mothballs. I changed the water level desiccant. I cleaned the flux and rad sensors and the camera window. The wash reservoir was mostly full, and we topped it off.

Joe cleaned the conductivity sensor, which was a bit muddy inside. The top of the conductivity sensor was out of the water, so we lowered it. We put minidot sn 899502 back in the water, off the east end of the tower between the scaffolding and the wooden platform.

LI-7500 readings (sn 0418 --> sn 0418 after cleaning --> sn 0041):
CO2 389ppm --> 416 --> 415
H2O 668ppm --> 441 --> 421
T 23.4C --> 22.3 --> 23.9
P 101.6kPa --> 101.6 --> 101.5
SS 90--> 97 --> 99

LI7700 readings (before calibration -->after cleaning --> after calibration):
CH4 1.96ppm --> 1.94 --> 1.95
RSSI 47--> 75--> 71

We left around 14:30 PDT to head to East End. Ariane remained at WP to continue her core work until 3.30 PM.

1 photos found

20200519WP_Upper25cm.jpg ( 2020-05-19 00:00:00 ) Full size: 1920x1440
Upper 25 cm of uncompacted soil core collected at WP