Field Notes

When: October 24, 2002 d297 Friday
Where: Tonzi/Vaira Ranches
Who: Sno Antonaros & Ted Hehn
Weather: Sunny to partly cloudy, grey skies to the west, mild breeze, temperature around 15C

Trip Purpose: Check 3 flux systems and download data, soil moisture probe readings, dendrometer readings, measure voltage of all field batteries (w/ voltmeter), clean solar panels, and check precipitation gauge, and install Net Radiometer (not completed).

Overall: All flux systems at the Tonzi ranch were running well, however, there problems were encountered with the Vaira surface renewal CR10X and the Campbell MD9. All electric fences were in good condition and fully operational. Trees in senescence phase. Oak canopy still about 50% brown, whereas corresponding percentage was much lower for the pine leaves.

Problems: At Tonzi tower, the CR10X at the met station in the tower enclosure displayed an error reading E08 (number of table overrun occurrences). This problem was fixed by Ted as *B5 parameter=99 was reset to 0 and the execution interval was changed from 4 to 6. In addition, the anti-bird devices upon the tower’s sonic anemometer was dislodged (and subsequently fixed) and two of the three “spikes” were missing on the tower’s IRGA (these were not replaced). Furthermore, the line quantum sensor under the tower canopy was not “level” and should be repositioned and obstructive grass should be cleared.

At the Vaira site, the surface renewal data collection system failed, the execution interval was exceeded *B4=99 and the CR10X was giving a constant Error08. Ted also found that the Campbell MD9 was unable to communicate with a fully operational CR10X that was brought with us from the lab. Ted removed both the CR10X and the MD9 from the Vaira site, thereby rendering the surface renewal system temporarily non-functional. A spare CR10X and MD9 could be installed to the site, but since the memory capacity of the spare CR10X is considerably lower than that of the original, a new program for polling the data logger and uploading the data to the PC would need to be generated.

Tonzi Ranch:

Tower system: Fence OK.

PV reading 13.6V, 4.5Amp and 2.5Amp at 12:38 p.m.

After changes noted above and data downloaded, reboot PC, w, u, v, Tsonic, q and CO2 outputs on-scale.

In addition, Precipitation gauge was zeroed and tested by performing 10 manual inversions resulting in a reading of 1.524.

Batt_V at the fence was 12.9V; the CR23X data logger on the tower read 13.93V and the solar panel near the pump read 13.13V

Tonzi Floor: Fence OK.

PV reading 13.4V, 2.5Amp, 2.3Amp at 3:15 p.m.

After data was downloaded, reboot PC, w, u, v, Tsonic, q and CO2 outputs on-scale.

Batt_V at CR10X was 13.4V, solar panels were 13.39V and the fence read 11.66V.

In addition, the Batt_V near tree tag 251 was 12.45V and tree tag 78 read 12.44V.

Jianwu’s site: Fence OK.

Batt_V at solar panels read 12.99V and 13.04V.

Batt_V for data logger read 12.44V.

Unfortunately, as I was unaware, I did not check the CO2 sensors to obtain the appropriate readings.

Dendrometer reading:

Jday: d297
Date: 24Oct2002
Time_pst: 2:20 p.m.
Conditions: Partly cloudy, cool (low to mid 60s), breezy

Soil Moisture Reading:

Jday: d297
Date: 24Oct2002
Conditions: Sunny and warm in open field, but cool under shaded canopy, with little to no breeze.
Note: All measurements were taken twice @ each moisture point probe using the MP-917 @ approximately 2 min. intervals.

Vaira Ranch:

Surface Renewal System: Fence OK. We arrived at the Vaira site at around 6:00 p.m. It was at sunset and light was rapidly disappearing. Temperatures were cool and breezy.

PV reading 12.3 V, 0.00 Amp and 2.8Amp at 6:29 p.m. (at this time there was virtually no twilight).

Soil Moisture readings were collected and surface renewal CR10X & MD9 were removed. Put zip drive in plastic zip-lock bag.

Jday: d297
Date: 24Oct2002
Conditions: Near sunset, very cool with little light and strong breeze.
Note: All measurements were taken twice @ each moisture point probe using the MP-917 @ approximately 2 min. intervals.

Notes:

• Surface Renewal System should be returned to the lab (per lab meeting 10/25)
• Installation of Net Radiometer at the Tonzi Tower enclosure on the tower met station data
• Send in CR10X and MD9 for repair (if necessary)
• Design method to keep anti-bird devices on Sonics and IRGAs
• Reposition and clear obstructions for line quantum sensor at the Tonzi Tower enclosure
• Standardized naming protocol