Field Notes

Bouldin Alfalfa: 2021-12-14 13:00:00 (DOY 348)
Author: Daphne Szutu
Others: Carlos

Summary: Swapped 7500 for calibration, veg height, removed HMP intercomparison sensors + datalogger, changed phenocam clock

2021-12-14
Bouldin Alfalfa

Carlos and I arrived at 13:00 PST. It was chilly with a cold breeze. It was clear overhead with some cumulus clouds in the lower 1//3 part of the sky. There was an atmospheric river in the past 48 hours that delivered about 50-75 mm (2-3 inches) of rain here. Our dirt road had some puddles on it, but it was ok to drive on. The dirt road that is parallel with the levee had rather large puddles so I was glad we didn't have to drive on that. The alfalfa was short and the field was firm enough to drive on.

The barn had piles of big gray plastic blocks which were labeled "Muscle Wall." We looked it up online and found that it's a 4' high barrier marketed primarily for flood control or water diversion.

Carlos cleaned flux and rad sensors and topped off the wash reservoir, which had been about 1/2 empty. I downloaded met, camera, and USB GHG data. I downloaded the FD data and cleared its memory. 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.

I changed the phenocam clock from 2021-04-12 to 2021-12-12. The time was the same, only the date changed. I don't know why, but sometimes the Stardot camera resets from December to April.

Carlos took veg height measurements.

I downloaded the HMP intercomparison data and Carlos removed the sensors and datalogger to bring back to the lab.

Sensors removed:
HMP45 sn T1250012
ATMOS14
CR1000 sn 23865

We swapped the LI-7500 for calibration: sn 0035 came off and sn 75H-2514 went on the tower. I couldn't find the 7500 configuration file so I uploaded an older version of the config file and updated the CO2/H2O Span/Zero coefficients using the database calibration entry. I then saved the updated config file with the current date. I updated the pressure coefficients and reset the 7550. I checked that the USB was logging and the 7700 was connected.

LI-7500 readings (0035-> 0035 clean --> 75H-2514):
CO2 408ppm --> 408--> 422 (looking at this back in the lab, I think this jump is suspicious. I need to take a closer look at the new config file. Next time if I don't have the config file I should probably just not swap the sensor.)
H2O 379ppm --> 347 --> 330
T 10.8C --> 10.7 --> 11.0
P 101.1kPa --> 101.1 --> 101.2
SS 99--> 99--> 101
LI7700 readings:
CH4 1.99ppm
RSSI 61--> forgot to write after cleaning

We left at 13:55 PST.

Next Mowing: 2022-01-22

Veg Height (cm): Tape measure from ground to top of plant
17, 15, 12, 21.5, 9.5, 19, 12, 14, 11.5, 16.5, 7.5, 12, 17, 13, 21, avg = 14.6, stdev = 4.07

0 photos found

7 sets found

5 BA_flux graphs found