Field Notes

Field Notes:
Where: Tonzi Ranch
When D120, April 30
Who: DDB, Tess Krebs, Yadvinder Malhi

Cool day, light winds, high humidity. Rained the previous day and the soil was wet. Grass is very green, seeding and lots of wildflowers. Leaves on blue oak are fully extended. Tess has been here since early morning taking A-Ci measurements.

9:50 Checking out tower system. System is operating. Downloaded data. 1.33 Gigabytes free on the computer. We will need to offload data later this summer.

W: 0.7; u: 2.7; v:-1.1; T: 19.7; q: 1.84; c:1.78

Signals are aok.

10:05 checked filter paper on CO2 profile filters. It is still pretty clean.

Tried to hook coax extension to cr10x-7, but the new cable was too short. We need a male-male connector to splice the cables.

10:24 Checking forest floor system. 1.1Gigabytes free. Flux system aok

W: 0.3; u: .4; v:0.78; T: 23.8; q: 2.08; c:1.8

Checked signals on the Campbell data loggers.
Cr23x6: Tair 13.3, RH 61.7%, batt volt. 13.5
Cr10x3. soil moisture probes were on scale. About 800 mv, reflecting wet conditions.
Cr10x2. Soil temperatures were in the 13C range. Cool wet soils.

Loaded md9_tz7.exe software on the computer and set up the tasks, so we can poll the CO2 profile system when the coax is connected. The programs are not scheduled to be polled as yet and the program will be called every 30 minutes. Next time the field leader needs to implement the program and double check the times on the software calls.

Downloaded flux data. Forgot to download met data!

10:48 Climbed tower and downloaded data for CO2 profile on cr10x_7.dat.

Checking power systems
Tower Prostar 30. Batt volt 14.7, gen amp 0. load 1.5 amp
Floor. 14.1 volt, 14.1 gen amp, 1.1 load.

Saw that Gophers are burrowing near the CO2 soil profile system under the tree. The probes need to be moved!

Took soil moisture profile measurements.

newly installed sensors seem biased low. May take a while for the probes and soil to readjust.

Took Dendrometer readings

Measured height of CO2 profile system
C1: 0.59 m
C2: 1.80 m
C3: 5.94 m
C4: We could not reach C4, but it was 23.0 m to the base of the sonic. The tube is about 10 cm higher.

Sampled grass height and sampled LAI at 2 locations.

Vaira Ranch

14:20 Puffy clouds. The grass is much taller than at Tonzi!. And grass in the enclosure is >>> than outside. We are definitely biasing and insulating the soil heat flux plates!

1.4 Gb free on computer.

Tair 18C; Rh 53%

Rain had cleaned the radiometers. But we still need to move the rad boom down to reach and clean sensors.

PAR 1700, diffuse 170 micromoles.

Downloaded data, took soil measurements.