Field Notes

<--2023-07-06 11:20:00 | 2023-08-15 11:30:00-->
Other sites visited today: Tonzi | Mayberry

Vaira: 2023-07-25 08:30:00 (DOY 206)
Author: Daphne Szutu
Others: Dennis

Summary: Regular data collection/cleaning, sonic heading varied with repeated measurements, cleaned solar panels, visited pond

2023-07-25
Vaira

Dennis and I arrived at 8:30 PDT, an early start today to beat the forecasted 37C high temperature. It’s been three weeks since the last visit, and there’s been a few hot spells with temperatures >40C over a few days. It was warm, sunny, and clear, with a slight breeze from the west. The watering hole still has plenty of water and the trees are looking good.

I downloaded met, cam, and USB GHG data. I downloaded both FD chambers, set their clocks, and cleared their memories. Dennis measured the well and cleaned the radiometers and solar panels. He reported that the solar amps increased from 3.7 to 4.1 after cleaning the panels.

Last time, I measured the sonic orientation after Dennis raised the eddy post, but my measurement was different from Joe’s record. The sonic heading has been measured at least four times between 2017 and 2023 at 15 deg true north. At the last visit, I measured it at 21 deg true north before and after the move.

Today I again checked the orientation for the sonic using my phone (iPhone 8 on xfinity) and Dennis’s phone (iPhone 11 (maybe) On Verizon). We confirmed we both have “Use True North” and, Location Services, and “Use Precise Location” enabled. I set up the ladder by the sonic so I could see the compass app in real time. My initial measurement was 20-21 deg true north. Dennis’s phone read about 23-24 deg true north. But, the measurement would change when we brought the phone down away from the sonic and then up again, ranging from 17-25 deg true north. When I used both phones, one on each side of the north spar, they would always read slightly different numbers, with the differences ranging from a few degrees to 10 degrees. I tried restarting my phone, but it didn’t make a difference in measurements. I’m wondering if having the 2 phones (with their metallic parts) next to each other affected each other’s compass measurements.

Dennis said he felt justified in never trusting wind direction data “within 10 degrees.”

We drove to the pond and collected its data. The staff gauge had some aquatic plants right in front, but I think it read 15.7 feet. We left the pond and headed to Tonzi at 9:10 PDT. I had to honk a few times to convince a bull to move out of the road.

Field Data

No tank data

Well Depth