Field Notes

Bouldin Alfalfa: 2019-08-07 16:00:00 (DOY 219)
Author: Daphne Szutu
Others: Robert, Ariane

Summary: Regular data collection/cleaning, veg height, swapped 7500 for calibration, shorted power tower but didn't have combo lock code--need to fix power ASAP

2019-08-07
Bouldin Alfalfa

Robert, Ariane, and I arrived at 16:00. It was sunny and breezy with blue skies and thunderclouds over the Sierras. The alfalfa was shin height and sparse, but already flowering. There were generous amounts of bird poop on the instruments and on the tower. The wash reservoir was mostly full; we topped it off.

Robert took veg height measurements. I collected met, camera, USB, and FD data. Ariane cleaned the rad sensors and the Arables. Robert cleaned flux sensors and swapped the 7500 for calibration: sn 75H-2180 came down and sn 75H-2150 went up. I uploaded a new configuration file, updated the pressure coefficients, and reset the box.

Ariane tried to take spectral measurements, but the reference measurement was oversaturatedâ€”I need to follow up with Ocean Optics to see if we can correct this for next time.

One of the HMP fan wires and one of the fan power wires had broken, and the screw terminal was corroded. We swapped out the screw terminal and stripped the wires. In the process, we shorted the two power wires together and flipped the 5A circuit breaker inside the solar charge controller box. I was measuring <0.5 V from the black/white 10 gauge wire in the datalogger box that supplies power from the solar charge controller box. We werenâ€™t able to open the combo lock on the solar charge controller box, so I left the black/white 10 gauge wire disconnected for now and need to come back ASAP to get the tower up and running again.

I didnâ€™t write down 7500 readings after the swap, but the CO2 and H2O numbers looked reasonable. I was in the middle of clearing the FD data when the power went out, so Iâ€™ll have to check that next time.

LI-7500 readings (sn 75H-2180 --> sn 75H-2180 clean):
CO2 386ppm --> 398
H2O 737ppm --> 613
T 31.8C --> 32.1
P 100.9kPa --> 100.9
SS 97--> 101 after cleaning
LI7700 readings:
CH4 1.9ppm
RSSI 51-->80 after cleaning

We left at 16:50.

Next Mowing: 2019-08-14

Veg Height (cm): Tape measure from ground to top of plant
41, 34, 33, 38, 33, 28, 39, 35, 27, 33, avg = 34.1, stdev = 4.46

0 photos found

7 sets found

5 BA_flux graphs found