Field Notes

When: Nov 18, 2004, D323
Where: Tonzi Ranch
Who: D. Baldocchi and T Hehn

Arrived at the ranch around 1015. Low overcast, foggy day. Light winds, moderate temperature. Grass is green everywhere. Little dry grass is left. Trees are a mix of senesced and bare.

Major limb on the Liukang PS tree fell and landed on the CO2 profile system.

We did lots of site work today. The main mission was to move and install the CO2 profile system.

1. Ted was working on the tower system when I arrived and put the new Windows version of the flux system. He noted that the ground from the pc to batteries was 35 kohm!. Around 4pm I noticed spike on the system when crows lit on the sonic and irga.
2. Took soil moisture measurements in am.
3. checked met sensors and forest floor flux system. Ted downloaded data. Met and soil Tc and moisture sensors were working and on scale.
4. Moved west (under tree) soil CO2 profile system to a grove of trees north of Jianwu’s transect. The system was installed 0.75 m from the base of the tree. The tree was 1.57 m, dbh.
5. We used the same sensors as before. The system is:
   #1 2 cm
   #2 8 cm
   #3 16 cm, 2% sn X520002
   #4, 4 cm 3% sn Y0710013.

I started inspecting the sensors alter installing the third one. We have a new box and installed new soil thermocouples. The soil was moist and perfect for installing the sensors. Used soil core to drill probes and sealed sensors in AL tubes, like Jianwu. This approach seems to work. Used the new gortex socks on one sensor. Hope it works, as the seal on the sewing was not the best. The sensor are withdrawn about 2 to 3 cm from the bottom, so they should not sit in water.

Installed sensors in the Open, East station. Used new and freshly calibrated probes. Use 1% probes in open and 2 to 3% under the tree.

#1 2 cm, sn Z2720014, 1%
#2 4 cm sn Z2720011, 1%
#3 8 cm sn Z2720012, 1%
#4 16 cm sn Z2720013, 1%

Prior to installation the sensors lied on the ground, for a quick and important inter-comparison, to confirm zero offsets. This is a good idea and something to be repeated in the future when swapping sensors.

430 getting dark, heading home. Ted will remain another day and finish set up.