Field Notes

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Other sites visited today: Sherman Island
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Twitchell Rice: 2010-05-20 08:00:00 (DOY 140)
Author: Joe Verfaillie
Others:

Twitchell
5/20/2010

Arrived about 8am. Mostly clear with a few thin, high clouds, sunny, cool warming quickly. Wind out of the west swinging to the north. Rice is about 8-10cm tall, lots of weeds in the field. The field is not flooded yet. Sheep on the east side of the road from the white box and further south.

The generator and all systems were running when I arrived.

I disconnected and removed the big batteries (Deka 8G8DLTP) that Steve Deverel lent us from the solar panels at the original tower location. At our current site, I moved the 12VDC supply from the solar charger to connect directly to the 12V buses then shut down the solar charger. I then removed the four deep cycle car batteries and replaced them with two of the big batteries. In reconnecting the solar charger to the batteries and swapping the 12VDC supply back from the buses to the solar charger, I lost 12VDC power for a short period – there will be small gap in fast data.

I put the third big battery in the trailer near the other solar panels.

I removed the LI7700 from the tower for installation at the Sherman Levee site. Analog wiring: 2H wht, 2L brn, 3H grn, 3L yel, 4H gry, G tan.

I reinstalled the netbook with new USB to Serial converters. Seems the old keyspan ones were killed by heat when the AC quit.

I swapped cards on the CR1000 and loaded the older version of the program without the modifications from the LI7700.

I copied data from the netbook – no web cam since moving it to Vaira.

The vent fans seem to be working well.

The HMP45 ventilation fan is dead, need to replace next time out.

Soil heat flux plate number 2 was uncovered. Its cable probably got stepped on and pulled it out of the ground. Reinstalled.

I calibrated the LGR:

Initial readings:
9:35, 19.99C, 138.24Torr, 14.071usec, 10Hz, 1.8530ppm, 8187ppm, 406.97ppm

bypass valve adjusted to 143.55Torr. Calibrated with 3.276ppm CH4, 433.0ppm CO2 tank with 1800psi

Pre cal: 9:41, 138.16Torr, 1Hz, 3.220+-0.005ppm, 444+-1ppm
Post cal: 9:48, 3.278+-0.002ppm, 432+-1ppm

Ambient conditions after calibration:
9:50, 20.02C, 143.90Torr, 14.069usec, 10Hz, 1.8610ppm, 8332ppm, 390.55ppm

Left for Sherman about 10:30

1 photos found

20100520TW_Sheep.jpg ( 2010-05-20 10:01:42 ) Full size: 2048x1536
Sheep along the road next to the rice field