Field Notes

<--2023-08-08 13:20:00 | 2023-09-12 13:30:00-->
Other sites visited today: Gilbert Tract | Mayberry | East End

West Pond: 2023-08-23 13:45:00 (DOY 235)
Author: Joe Verfaillie
Others: Daphne

Summary: Standard data collection, hot, Hot, HOT. Testing LI-7810 chamber system, tested 7700 wash - ok, replaced DC-DC converter and fixed loose connection

West Pond
2023-08-23

Daphne and I arrive at about 13:45 PDT. It was sunny, hot and muggy – I was much more comfortable at Tonzi last week at about 15F higher air temperatures. Lots of wasps buzzing about. The inlet was running and the water level was 67cm – pretty high. The tallest tules are higher than the radiometers. The surrounding willows are encroaching and much taller than the eddy measurements. The tower needs to be releveled, NDVI sensors are dead, some thermocouples are broken and the old water level sensor needs to be dug out of the tule thatch. We are looking at needing to put in a lot of effort to continue questionable measurements. Once we have the data from the latest lidar flight maybe we can discuss the future of this site.

There’s a long dead sheep in the northwest corner of East Pond polluting the air.

We are testing our new Licor LI-7810 (CO2/CH4/H2O) analyzer and LI-8100 Smart Chamber. We set a collar at the edge of the water, the water making a seal and did five reps. It was at a little bit of an angle but I don’t think that makes a difference. CH4 fluxes were really high (hundreds of nanomoles but seemed of good quality) CO2 was small around 3 micromoles.

Daphne collected the data and swapped the desiccant in the miniDot and water level cable.
The 7500 read: 393ppm CO2, 991mmol/m3, 35.1C, 101.1kPA, 97SS – 100 after cleaning
The 7700 read: 2.15ppm CH4, 55RSSI – 90 after cleaning.
The wash reservoir was full – we tested the spray and spin which were okay. Daphne adjusted the eddy clock by +45sec and restarted logging.

Power has been jittery here. We decided to swap the DC-DC converter for one with slightly longer leads and in the process found that the pluggable screw terminal was loose on the positive pin. I was able to bend some flanges in tighter on the female end and make a better connection. Things should be better. We restarted the Canon camera after messing with the power.

We left at about 14:30 PDT

1 photos found

20230823WP_TowerVeg.jpg ( 2023-08-23 11:47:40 ) Full size: 1920x1088
The tower is being over run by vegetation