Field Notes

Trip note On Feb 21, 2003
Who: Liukang Xu & Jianwu Tang
Weather; sunny and warm, temperature around 60s

Tonzi site: 10:00 arrived. Two people from Chemistry department pick up the tower davit.

Vaira site: 10:45 arrived. Fence OK. But the flux system was down since Feb 19 around 7:00am. Found the fuse from solar panel (+) to the PV regulator was burned out, replaced with new one. Afraid of too much current, disconnected two solar panels (after talked to Ted on the phone). With 6 solar panels, PV reading 12.9, 23.0 and 3.0 at 11:45am. Met and soil sensors OK. Downloaded the data and reboot pc, six channels from gillsonic.exe gave me right output.

Grass height measurement (m=4.75, n=20, std=1.52). Took 3 LAI samples.

Soil moisture reading:

Tower system; fence Ok, flux system running good. Download the flux data. Gillsonic output after reboot was OK. Replaced the desiccates for the Rs radiometer at the top of the tower.

Floor system: Fence OK, flux system running, pV reading 14.6, 20.4, and 2.0 at 12:10pm. Battery fully charged. Download data, and found lost communication with CR23X6 (the one at the top of the tower), since d47 300am. Climbed to the top of the tower, checked the data logger, its battery voltage OK (15.6V), can not see on the small screen because of water condensed inside. I am not sure the data logger is dead or just lost communication with pc, the watchdog working OK. Informed Ted this problem.

Grass height measurement (m=4.4 cm, n=25, std=2.12cm)

Dendrometer reading

Jianwu did soil respiration and stem respiration.