Field Notes

When: Date: Aug. 17, 2004, Day: 230, Watch Time: 10:30 am
Where: Tonzi/Vaira Ranch
Who: Dennis and Siyan
Weather: Sunny, nice, warm but not hot, breeze
Phenology: dead grass; Oak leaves turn to yellow.

Summary & Problems

1. Overall EC systems were running well. Data were downloaded, but 10-day data were lost in Vaira because the laptop wasn’t restart properly on schedule. The laptop in Tower site was turned off at the time of visiting. About 3-day data were lost in Tower site.
2. Solar panel’s Amps = 0.0 amps. Something wrong with the power system?
3. Swap Li-7500 in Tower and Floor sites.
4. Correct PC’s clock by using GPS time. (Dennis put the GPS unit in the yellow tool box till on.)
5. Leaf samples were taken from the trees with Tag 222, 225,227,228, and 33. Those trees were marked by flaggings.

Tonzi_Tower Site

1. Fence and gate power: >12.0 v.
2. Panel and Batteries: 14.2 v; 0.0 amps; 3.8 amps.
3. When we got the site, the PC laptop wasn’t on.
4. Reading from Gillsonic screen before downloading data. (The value of H2O and CO2 should be in the range of 0 – 5 v.)

   Time	10:31:44
   Path/File name	TW_04230.flx
   	mean	std		mean	std
   w	1.17		Ts	34.948
   u	0.45		H2O	2.415
   v	-0.21		CO2	1.464

5. Download data. (Alt_X to close Gillsonic.exe; close PC208W before copying.) About 3-day data were lost. The last RAW data before downloading was TW2270450.RAW.
6. Correct PC’s clock by using GPS time. PC’s clock (10:39:54) was 3 minutes faster than GPS time (10:36:34). Reset up at 10:38:44.
7. Swap Li-7500: remove sn 0041, install sn 0418.
8. Check calibration cylinders:
   CO2 2000 psig; flow 8 psi.
   N2 900 psig; flow 10.0 psi.
9. CO2 profile looks OK from Floor PC, but cell temperature was 30^oC instead of 50^oC. Manually calibrate Li-800 was not done.
10. Dennis climbed the tower and cleaned up the sensors.
11. Checking CR10X and CR23X:
    CR10X OK. CR23X – NR_2 = -9999.

Toniz_Floor Site

1. Fence and gate power: >12.0 v.
2. Panel and Batteries: 13.6 v; 13.8 amps; 2.5 amps.
3. Reading from Gillsonic screen before downloading data. (The value of H₂O and CO₂ should be in the range of 0 – 5 v.)
   

   Time	10:53:51
   Path/File name	FL4_230.flx
   	mean	std		mean	std
   w	0.018	0.226	Ts	35.959	0.827
   u	0.17	0.243	H2O	2.877	0.114
   v	0.03	0.972	CO2	1.559	0.101

4. Download data OK. Readings were OK from Gillsonic screen after downloading OK. The screen of PC was flashing.
5. Correct PC’s clock by using GPS time. PC’s clock (10:56) was 2 minutes faster than GPS time (10:54). Reset up at 11:08:15.
6. Swap Li-7500: remove sn 0035, install sn 0073.
7. Check MD-9 system connections. OK.
8. Soil CO2 profile probes worked well. [CO2]_tree > [CO2]_grass
9. CO2 profile: cell temp still was lower than supposed 50oC. [CO2] = 404 ppm. The high value may indicate there was not much photosynthesis going on. Tank = 428.7 ppm, Cal = 419 ppm.
10. Close gate and set up fence.