Field Notes

Hill Slough: 2023-01-06 09:30:00 (DOY 6)
Author: Daphne Szutu
Others: Dennis

Summary: Regular data collection/cleaning, redeploy EXO, swapped channel power pack, storms this week and more rain to come

2023-01-06
Hill Slough

Dennis and I arrived at 9:30 PST. It was overcast, cold, and breezy. We’ve had a string of atmospheric river storms since late December. More storms with potentially high wind are expected this weekend and next week. The water was high and turbid and the staff gauge read 4.94ft at 10:12 PST.

When we arrived a cormorant was sitting on the radiation boom, drying its wings.

Joe and I had stopped by earlier this week to remove the EXO for calibration. I calibrated the EXO yesterday and we deployed it today. I couldn’t find the protective plastic sleeves, so this time the EXO is deployed without them. I put copper tape all over the outside of the plastic guard. (Later Ari told me the sleeves were in the sensor cabinet by my desk. I moved them to the cabinet by the door with all the other EXO stuff.) The real-time EXO data checked via the CR23X display was reasonable.

Sensors deployed:
sn 22E106072
sn 22E100649
sn 22D102641
sn 22C103416

We’ve been having issues with low power with the channel sensors, so today I had a new 12V lithium power pack (capacity 99Wh). When I went to swap it, both outgoing wires on the DC-DC converter fell off from corrosion. I couldn’t find a replacement converter so I soldered both of the wires back on. The butane canister in the blue bag was empty so Dennis drove to the Ace Hardware right across the street to buy another one.

Soldering took a while. At first I thought I should solder on the truck bed to avoid the fumes, but it was too cold/windy for the soldering iron to get hot, so I moved everything to the back seat. Then I kept underestimating how much butane the iron would hold. The iron would get hot enough to do one thing, then it would run out of fuel and cool down again, so I would have to refill with butane and then start over since all of the solder had cooled down by then. The wires also weren’t taking solder very well; I ended up putting a huge blob of solder on the board and sticking the wire in while the solder was still melted. I put a little of the clear grease on the solder spots to try to slow down corrosion. I will bring a new DC-DC converter next time. (I later found a spare DC-DC converter in the laptop bag, but we were already at BA.)

After repairing the DC-DC converter, I hooked up the new lithium power pack. The EXO and CR23X were both running but I forgot to check on the HYDROS21.

At the tower, I downloaded met, cam, and USB GHG data. NDVI and difPAR were NAN. I tried power cycling them but it didn’t seem to make a difference. I’ll troubleshoot more next time as there’s not much vegetation activity happening right now.

Dennis cleaned flux and rad sensors. The reservoir was ¼ full; he refilled it.

I collected a porewater sample from the tower sipper to take back to the lab and measure for conductivity later.

Sample, temperature-compensated conductivity, temperature, notes
Porewater, 17.74 mS,, Sample stored in fridge before being measured

At the channel, I downloaded the miniDOT data but didn’t change its desiccant because spares were in the truck. The pantyhose is doing a great job of keeping the sensor clean.

The 7500 read: 436ppm CO2, 425mmol/m3 H2O, 10.7C, 100.7kPa, 100SS – 101 after cleaning
The 7700 read: 2.42ppm CH4, 37RSSI – 70RSSI after cleaning

We left at 11:25 PST.

1 photos found

HS_picam_20230106_0815.jpg ( 2023-01-06 08:15:06 ) Full size: 1917x1440
Coots on water