Field Notes

<--2010-04-15 12:00:00 | 2010-04-29 11:30:00-->
Other sites visited today: Sherman Island

Twitchell Rice: 2010-04-22 09:00:00 (DOY 112)
Author: Joe Verfaillie
Others:

Summary: Put all soil sensors back in ground, power was out, LGR would not line lock when power was restored.

Twitchell
4/22/2010

Arrived about 9am – cool, partly cloudy, breeze from the northwest shifting more north a lessening. Talked to Jim. Field one 1 is planted and will only have a tractor in it again to spray some fertilizer just before flooding in 2 or three weeks.

I put all of our soil sensors back in the ground (diagram to come) and swung our radiation boom back out over the field. The water table was about 24in down when putting in the well. The top of the pipe was 8" above the ground and the pipe is 48" long. The sensor was 3" above the bottom of the pipe or about 37" below the ground surface.

The power was out when I got there. Probably a tractor had pulled our power line loose on the 17th. CO2 flux may have run on batteries without interruption but need to check data. I repaired the power line and power was restored. We are still on the sign generator, the big generator is only running 4 or 5 hours a day until flodding.

The LGR would not line lock CH4/H2O when power was restored. Initially the cell temperature was about 10C and I let it warm up to 18C with no lock and many restarts. Finally I called LGR and got their maintenance password to change line lock settings from 0.165 to 0.185 and this did the trick.

Initial readings
11:35, 18.50C, 144.60Torr, 13.940usec, 10Hz, 2.149ppm, 12039ppm, 398.07ppm

Calibrated with 3.276ppm CH4, 433.0ppm CO2 tank, last cal Mar 11, 2010
Precal 11:40, 138.24Torr, 3.270+-0.002ppm CH4, 425.0+-1ppm CO2
Postcal: 11:44, 138Torr, 3.279+-0.002ppm CH4, 433.5+-1ppm CO2

Swapped card and copied data.

Returned to Sherman about 11:45

3 photos found

20100422TW_PlantedSoilSensorsIn.jpg ( 2010-04-22 11:38:09 ) Full size: 2048x1536
view of field site