Field Notes

Bouldin Corn: 2021-10-21 16:15:00 (DOY 294)
Author: Daphne Szutu
Others: Joe

Summary: Regular data collection/cleaning, corn harvested, moved soil sensors into field, retaped some thermocouples, tested tipping bucket--adjusted

2021-10-21
Bouldin Corn

Joe and I arrived at 16:15. It was mild, overcast, and breezy. It has been lightly raining on and off over the past few days; this weekend we are will have an atmospheric river with an expected 12-20 cm rain, wow! There were some ducks or geese flying overhead, and a some hunters and their dogs were hanging about the Duck Club building.

The corn has finally been harvested and the farmers took it all downâ€”no patch of corn in front of our tower this year.

Joe moved the Planet Lab Arable out to the field. It was 214cm agl and its status light were green, green, red, unlit.

Joe removed the soil sensors from under the tower and installed them out into the field. The soil was still dry and dusty - maybe not much rain here. Sensors moved: 3 sets of soil sensor where each set has a soil temperature thermocouple rods, a soil heat flux, and a Campbell soil moisture. The heat flux plates were installed at -2cm depth. He had to re-tape some of the thermocouples to the rods.

Set 1 â€“ Profile to the N, soil moisture at -10cm depth. The -2cm thermocouple was loose; re-taped.
Set 2 â€“ Profile to the south, soil moisture at -20cm depth. The -2cm and -4cm thermocouples were loose; re-taped.
Set 3 â€“ Profile in the middle, soil moisture sensor at -20cm depth. Re-positioned and re-taped the -32cm thermocouple which had slid up near the -16cm position.

He also moved the Theta soil moisture probe out into the field, but it has a much shorter cable so itâ€™s right in front of the tower. It's right at the surface but should probably be buried so that it's temperature isn't influenced by direct sunlight.

The forced diffusion chamber remained under the tower.

I downloaded met, cam, and USB GHG data. There were gaps in the mux sensors againâ€”Joe tightened the Control port on the mux 1/4 turn. I downloaded the FD data and cleared its memory. I downloaded the PA data and cycled its power. I downloaded the IRT data by swapping the microSD card and using CardConvert to convert the fast data to TOB1 and the slow data to TOA5. The wash reservoir was mostly empty; I refilled it.

We cleaned flux and rad sensors. The top sensor of one of the Arables looks like itâ€™s starting to flake (see photo).

We calibrated the tipping bucket sn 65548-615. I cleaned out the tippers, which were pretty clean. We dripped 240ml of water through the bucket using a peristaltic pump powered with a lithium battery. This should result in 50 tips in about 20 minutes. We got 54 tips. We turned its sets crews 1.5 turns CCW. I will test it again at the next visit to see if the adjustment was sufficient.

LI-7500 readings:
CO2 400ppm
H2O 987ppm
T 22C
P 101.6kPa
SS 98 --> 102 after cleaning
LI7700 readings:
CH4 2.1
RSSI 12 --> 79 after cleaning

We left at 17:05.

Looking at the data back in the lab, there was a corrupt GHG file from 2021-10-16 11:00. There was some gibberish interspersed with a few lines of data dated in early October. I deleted the gibberish and early October data. The data from 11:53 to 13:46 was missing. The other data streams also have gaps at this time, so itâ€™s probably a power outage.

3 photos found

20211021BC_ArableFlaking.jpg ( 2021-10-21 16:59:47 ) Full size: 1920x1440
Arable sensor on top is slightly flaking

20211021BC_CornHarvested.jpg ( 2021-10-21 17:07:18 ) Full size: 1920x1440
Corn has been harvested! All the corn has been taken; no personal corn patch in front of our tower this year.