Field Notes

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Other sites visited today: Bouldin Corn | Bouldin Alfalfa

Hill Slough: 2022-09-16 07:45:00 (DOY 259)
Author: Daphne Szutu
Others: Carlos, Kat, Balt

Summary: Regular data collection/cleaning, removed EXO to bring back to the lab for upgrades/calibration, sipper water sample, went to Rush Ranch with Kat and Balt, first fall precip expected in a few days, record-breaking heat wave last week.

2022-09-16
Hill Slough

Carlos and I arrived at 7:45 PDT. It was cool with fog over the hills with a strong breeze from the west; first fall precip is expected in a few days. Last week 2022-09-05 to 2022-09-08, most the Bay Area had a record-breaking heat wave with 3 days of all-time high temperatures recorded.

Kat and their colleague Balt from the same USGS Biogeochemistry group joined us around 8:30 PDT.

The staff gauge read 4.6ft at 6:57 PST.

We started at the channel. I downloaded the miniDOT data but I didn't have fresh desiccant on hand--I used all my minipaks yesterday at the other wetland sites. I scraped some barnacles off of the black plastic part of the miniDOT (not on the sensing foil). There were many tiny opposum shrimp (Order Mysida) on the miniDOT and on the eosGP.

Later, after Kat and Balt arrived, we pulled up the EXO sn 22C103416 to remove and bring sensor and cable back to the lab. There was a hole in the copper mesh and a small sculpin hanging out in the bottom of the cap. We removed the cap and there were A LOT of opposum shrimp all over the sensors (volume of shrimp ~ 500cc, or 2 cups) in addition to barnacles and some sort of encrusting worm on the sensor bodies. The central wiper was still going and the sensor windows actually didn't look too bad. We rinsed most of the shrimp off and packed up the sonde to bring back to the lab. Balt told us that the pH probe likes to remain moist, so he wrapped a wet paper towel around the probe and put the whole sonde in a black garbage bag.
The EXO2 was removed along with the following sensors:
Turbidity sn 22E106072
FDOM sn 22E100649
pH-ORP sn 22D102641

Ari will calibrate the EXO and we will adapt the cable so we can wire the sonde to the channel CR23X where the data will be sent to the CR1000 along with the other water sensor data.

I wiped off the solar panel for the CR23X. The lithium battery had 4 of 5 LED lights on. The CR23X voltage was 11.5V.

At the tower, Carlos gave Kat and Balt an overview of our sensors. I downloaded met, cam, and USB GHG data. Carlos cleaned flux and rad sensors and topped off the wash reservoir. Looking at the data back in the lab, the 7700 RSSI signal was noisy, but Carlos didn't remember anything unusual in cleaning the 7700.

I sampled water from the sipper. I forgot to bring a new vial, so I used the old sample vial. I triple-washed the vial with sample water before filling it with fresh sample water. Ari will take this vial and the previous vial from 2022-08-31 to UCSC to measure conductivity.

The 7500 read: 395ppm CO2, 680mmol/m3 H2O, 16.7C, 101.7kPa, 96SS before and 99 after cleaning
The 7700 read: 2.0ppm CH4, 40RSSI – 72 after cleaning

We left at 8:50 PDT and went to Rush Ranch with Kat and Balt.

Kat will be taking over as lead tech for the Rush Ranch tower. They have a main tower (3 levels of scaffolding) with the flux sensors, HMP, and PAR in/out on the edge of the wetland. About 100m away in the wetland proper, there's a mini-tower about 100m away with a 4-way radiometer (and probably more). The met sensors on the main tower are on a CR23X and the flux sensors are connected to a 7550 and a SmartFlux2/radio for remote access. The 7700 RSSI was super low and we found that the wash box power cable had been chewed off near the wash box. Luckily they had a spare wash power cable in the truck to swap in.

0 photos found

4 sets found

20 HS_met graphs found