Field Notes

We arrived at 11:10. It was sunny and cool with thin wispy clouds and haze at the horizon. The sheep have thoroughly grazed our field. Joe scattered some castor oil pellets around the tower to discourage the ground squirrels.

We swapped the LI-7500: sn 75H-2514 went up, sn 0035 came down. I downgraded the embedded software for LI-7550 sn AIU-1557 from 8.7.5 to 8.5.0 to match with the calibrated sensor. I updated the configuration file, changed the pressure coefficient, and reset the box.

LI-7500 readings:
(sn 0035 before cleaning --> sn 75H-2514 after cleaning)
CO2 398 ppm --> 428 --> 440
H2O 578 mmol/m3 --> 290 --> 290
T 15.4 C --> 15.0 --> 15.7
P 102.3 kPa --> 102.3 --> 102.2
SS 85 --> 99 --> 103

I downloaded met, camera, soil CO2, and USB GHG data. Dennis cleaned the radiation and flux sensors. Sam did soil respiration. Joe re-focused the stardot camera.

We tested the tipping bucket and found that it was under-reporting rainfall: the program is scanning every 500 msec because of the rotating shadow band, so the rainfall is only recording if that 500 msec measurement corresponds to the regular 10 sec scanning interval. Once we move the rotating shadow band to a CR10x, this won't be a problem.

Joe set up 12 HMP sensors on the tower for a field comparison, 6 HMP60 and 6 HMP45. All sensors (except for one HMP45) are aspirated.

I re-wired the HMP60 from the TA met CR1000 to the HMP comparison CR23x because we are writing data every 10 minutes for the comparison.

The HMP cable and sensor are swapped for sn G4540021 and sn L1740420.

While Joe was setting this up, the rest of us went to EE and WP. We came back to pick up Joe and left at 14:05.