Field Notes

Trip note On Apr 16 2003 (d106)
Who: Liukang Xu & Tess Krebs

Purposes: instrument maintenance, data downloading (Liukang), and A/Ci curve measurement (Tess).

Weather; clouds in morning and windy, rain start around 1:00 pm

Tonzi site: arrived around 8:15. Heavy rain on previous two days (27.7 mm). Soil profile fully charged. Will be interesting to see how those heavy rains influence on grass GPP and ecosystem respiration, esp. during this peak growth period.

Tower system: Fence and flux system, and profile system were running good. From the period of d106 to d115, we missed 3-day flux data, probably still due to the watchdog program.

PV reading at the top of tower, 13.5, 0.0 and 2.1 and at the base of the tower, 13.5, 0.0, and 1.6. Download flux data and CO2 profiles data by laptop pc. Reboot pc, outputs from Gillsonic were all in the right range.

Floor system: Fence and flux system was working, all data loggers communicate with pc. PV reading 13.4, 9.8 and 2.2 with fully charged battery. reboot pc, w u v Ts, q, and CO2 channels are good.

Vaira site: arrived around 12:05. heavy cloudy. Very light rain. Fence OK and flux system running good. Grass is at the peak growth stage. Grass height (36±9.3 cm, n=35). PV reading was 13.4, 6.5, and 3.0 with fully charged battery. Reboot pc all channels are good.

Soil moisture probe reading:

Tess tried to obtain diurnal A/Ci curves, In the morning she had some troubles to run the li-cor 6400 because of wind. Then around 1:00 pm rain started when it was in the middle of 2^nd A/Ci curve, but we managed to finish the 2^nd curve with the help of her umbrella and my raincoat.