Field Notes

West Pond: 2013-06-05 14:45:00 (DOY 156)
Author: Cove Sturtevant
Others: Sara, Yanel

Summary: Lots of new growth. Tules under tower getting close to sensors. Inlet running but water low. Ant infestation in 7550. Took water samples. Updated 7550 firmware. Corrected pressure cal. 7550 clock was a day ahead, corrected.

West Pond
2013-06-05

We arrived around 14:45 PDT. It was sunny, warm (25 C), and breezy. The site has a lot of new growth, it has really taken off in the last few weeks. In fact, the tules under the tower have grown and the highest tips are within a meter or so from the boom holding the flux sensors. Sara and I discussed cutting these tallest ones down next week. The tules elsewhere are shorter, so we could see a net upward vertical wind speed as these tules under the tower continue to grow taller than the rest.

The inlet was running but the water under the tower was low and the CO2 sensor out of water. We decided to leave the sensor as-is since the water would probably rise back to normal very soon.

There was a sizable ant infestation in the 7550 box (see picture). Unfortunately, we didnt bring the ant bait with us (let this be a lesson to always carry it!). Everything was working okay, but ant bait needed next week.

Sara and Yanel took water samples while I updated the 7550 (s/n AIU-0666 with 7500 head 2176) firmware to version 6.5.2 and FPGA version 6.0.3. I downloaded the flux data first but left the data on the USB stick and reinstalled it afterward. All calibration coefficients and settings were retained after the update, aside from the ones mentioned in the rice notes (no problem here). The pressure calibration in the 7550 (A0 = 57.462 and A1 = 15.200) did not match the factory cal. I changed these to match the factor cal (A0 = 57.595, A1 = 15.231) and put a label with the correct pressure coefficients inside the 7550 box (working around the ants).

I noted that the clock on the 7550 was a day ahead (reading June 6 and the correct GMT-8 time), so I set it to the correct date (June 5). As this will probably result in writing over yesterdays data, we should grab the data I downloaded to the computer and change the date before pulling in the data next week. I should have deleted the data on the USB stick before the time change to make Joe's job easier, but I didn't think of it. Sorry Joe.

7500 readings:
CO2 = 373 ppm (403 after cleaning, same after firmware update)
H2O = 760 mmol m-3 (403 after cleaning, same after firmware update)
agc = 34 (20.4 after cleaning, signal strength = 87% after firmware update)
p = 100.66 kPa (100.84 after pressure cal change)
sos = 349.5 m s-1

7700 readings:
CH4 = 1.89 ppm
RSSI = 28, bumped to 56.9 after cleaning
Reservoir was full.

MET looked good.

2 photos found

20130605WP_AntsIn7550.jpg ( 2013-06-05 12:18:24 ) Full size: 968x1296
Ants in the Li7550 box