Field Notes

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Sherman Island: 2010-09-21 07:45:00 (DOY 264)
Author: Joe Verfaillie
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Summary: Swapped diaphragm pump for rebuilt scroll pump, tested tipping bucket, sealed soil CO2 box.

Sherman
9/21/2010

I arrived about 7:45PDT. It was clear, sunny and warm with very little wind. However, most of the wind generators seemed to be turning. There was dew on the plants and the radiometers, but the LI7500 seemed clear. There is still a scattering of white pepper weed flowers. The east end of the field seems very dry, but there was some water in the ditches far to the west. There were a few cows near the tower when I arrived, but they moved off to the west as I entered the field.

Everything was running okay. LGR readings before I shut it down to swap in the rebuilt scroll pump (Note high CH4):
6:44PST, 24.34C, 130.66Torr, 15.793usec, 10Hz, 2.282ppm

Franks diaphragm pump (sn ) came out and our scroll pump (sn DG002) went in. The scroll pump sounds real smooth with almost no vibration.

In low flow mode the LGR is reporting 60 Torr and falling. I need to talk to LGR about this problem. No response to an email I sent.

LGR reading after scroll pump was installed and the bypass valve adjusted:
7:16PST, 24.08C, 145.52Torr, 13.995usec, 10Hz, 2.070, 14.1hr

I tested the tipping rain bucket with 473ml of water that should have resulted in 100+-3 tips or 25.4+-0.762mm. The data logger reported 24.384mm or 96tips. Considering I poured the water from a graduated cylinder to a bottle for transport to another container to dribble into the tipping bucket, I think this is close.

I copied the data and swapped the card before updating the CR1000 program to improve the quality of the slow data table.

The soil CO2 box was not sealed well and a host of critters were using it. It smelled like rodents and there a number of spiders in it. After pumping a bunch of silicon into the opening where the wires enter the box, I chased most of the spiders out. There was a black widow in the upper right corner that I chased out of the corner. It fell to the bottom of the box and I may have crushed it with the Vaisala transmitters but couldn’t find it. Also, there is a large wasp nest under the shroud for the ventilation fan on the outside of the box.

I cleaned the radiometers. I think some bird is still fouling the upward LED sensor.

I lubricated the lock on the field gate with WD40 and it works much better now.

I left for Twitchell about 8:50PDT.

3 photos found

20100921SI_Diablo.jpg ( 2010-09-21 08:51:39 ) Full size: 3648x2736
A little wisp of cloud in front of Mt Diablo