Field Notes

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Hill Slough: 2021-08-25 09:30:00 (DOY 237)
Author: Daphne Szutu
Others: Joe

Summary: Fixed thermocouples, swapped dfPAR sensor, changed eddy clock +3min

2021-08-25
Hill Slough

Joe and I arrived at 9:30 PDT. It was cold and windy with a layer of fog sitting over the hills to the west. There are fence posts and some reflectors up all along both sides of Grizzly Island Road. We parked across the street and walked in.

This was a maintenace trip, mainly to fix some thermocouples that have been NAN or giving sporadic data. We also wanted to fix the diffuse PAR that stopped giving data earlier this month.

Last week during a quick thermocouple inspection we found 2 thermocouples that did not have any soldering on them, so today we had planned to unwrap every thermocouple to check their soldering. However, the first few thermocouples that Joe checked on Profile A were all fine: +30cm (TC1), +15cm (TC2), -8cm (TC6), -16cm (TC7), -32cm (TC8). To these thermocouples Joe added some heatshrink with adhesive inside and rewrapped them in electrical tape.

We decided to just check the ones that were giving bad data instead of unwrapping all the thermocouples. The following thermocouples were bad, so Joe added solder and adhesive heatshrink to them:
Profile B, +32cm (TC9)
Profile C, -4cm (TC21)
Profile C, -8cm (TC22)

The dfPAR was still not working consistently. I connected to the CR10x to check its data, and the PAR data (fastPAR) were all really low values close to 0. We changed the PAR sensor, which fixed the problem. For the dfPAR setup, we removed sn Q100420 and installed sn Q100421.

I downloaded met, cam, and USB GHG data. I skipped the FD data since weâ€™ll get those next week with our regular data download trip. I cleaned the rad and flux and topped off the wash reservoir. I changed the eddy clock from 9:36 to 9:39 to match the laptop time, and then reset the 7550 to check that the clocks still looked good.

I chased some wasps out of the CR10X box and sealed the datalogger holes with duct putty.

LI-7500 readings:
CO2 393ppm
H2O 530ppm
T 19.2C
P 101.8kPa
SS 102 --> 102 after cleaning
LI7700 readings:
CH4 1.93ppm
RSSI 43 --> 73 after cleaning

We left at 10:50 PDT.

1 photos found

HS_picam_20210825_0945.jpg ( 2021-08-25 09:45:05 ) Full size: 1917x1440
Daphne and Joe on site