Field Notes

When: Jan 29, 2003 Wend.
Where: Tonzi/Vaira Ranches
Who: Liukang Xu, Jianwu Tang, and Ted
Weather Cloudy, temperature around 10^oC , foggy in the central valley, little better at the foothill. Grass green, not growing much since my last visit (Jan 4, 2003). Soil profile was saturated.

Trip Purpose: check 3 flux systems, replace all the li-cor 7500, and download data, soil moisture probe reading, dendrometer reading, grass height measurement, LAI sample at Vaira and Tonzi, Jianwu measured soil CO2 flux.

Arrived at Tonzi around 11:00.

Floor system: flux system and fence working good. Replaced Li-cor 7500 sn 0042 came off and sn 0073 went on. download data, found many key on the keyboard of the laptop not working, have to select all the files to copy. All the data loggers communications are good with pc.

Pv reading 13.9, 27.9, and 2.3 at 11:40. with fully charged battery.

Restart the pc after all the tasks, output from w u v Tsonic q and CO2 are good.

Tower system: Whole system was down due to the burned out of the PV regulator, After Ted replaced the PV regulator, I found out the system was down since Jan 23, 14:00 pm. Replaced li-cor 7500 sn 0041 came off and sn 0035 went on. Clean solar panel, lot of bird dropping.

Soil moisture reading: the whole soil profile is almost saturated

Dendrometer reading:

Took 3 LAI sample, and grass height measurement (m=5.0cm , std=1.32cm and n=25)

Vaira ranch: arrived 2:30 pm, fence is working but the battery voltage was only 10.2V, we replace the battery with a small one (15 amp hrs). The solar panel for that battery is too small.

Flux system was running good. PV reading 14.4, 12.7, and 2.7 at 13:15 pm with fully charge battery. Replace li-cor 7500 sn 0065 came off and sn 0418 went on.

Gillsonic outputs was on scale after reboot the pc.

Took 3 LAI samples, and grass height measurement (m=5.2cm, std=1.7cm and n=20).