Field Notes

Twitchell Rice: 2013-08-21 08:45:00 (DOY 233)
Author: Cove Sturtevant
Others: Joe, Laurie

Summary: Water level low. Calibrated 7700. Updated 7700 time to GMT+8. Installed new soil moisture probe.

Twitchell Rice
2013-08-21

We arrived about 08:45 PDT. It was sunny, cool (19 C), and super windy. The water level was low, just above the soil. The rice is getting heavy with seed. Joe and I attended to the tower and calibrated the 7700 while Laurie did spectral and LAI. Laurie reported that the battery for the spectral computer died midway through the spectral measurements.

7500 readings:
CO2 = 392 ppm (same after cleaning)
H2O = 650 mmol m-3 (same after cleaning)
signal strength = 81.0% (same after cleaning)
t = 17.2 C
p = 101.6 kPa
sos = 343.6 m s-1

7700 readings:
CH4 = 1.8 ppm (1.85 after cleaning)
RSSI = 35 variable (64 after cleaning)
Reservoir was full.

We calibrated the 7700 with zero gas and 4.995 ppm span tanks we brought with us. The zero offset was 0.01 ppm and the span offset was -0.025 ppm. We downloaded the GHG data because we noticed the 7700 time was not updated to GMT+8 (was still in GMT-8, causing the heaters to come on at the wrong times). I dont think this had any effect on the data sync to the 7550, but we downloaded the data anyway and changed to the correct GMT+8 time zone (at 07:51 GMT+8).

MET data looked good. We brought a replacement (CS615 job # 864 10, 8221-07) for the soil moisture probe (CS615_SM1) that we removed last week for maintenance. Readings looked good after install.

Joe added a bolt to the post for the camera boom so that the boom rotated to about level and stopped.

Cleaned radiation instruments.

The HMP45 RH data has looked a little different in comparison to West Pond. The ventilation fan was running and there was no obvious problem with the HMP45.

0 photos found

6 sets found

12 TW_met graphs found