Field Notes
<--2012-08-30 11:45:00 | 2012-09-13 13:20:00-->Other sites visited today: Tonzi | Sherman Island | Mayberry | Twitchell Rice | DWR Corn
West Pond: 2012-09-06 13:00:00 (DOY 250)
Author: Joe Verfaillie
Others: Cove
Summary: Calibrated 7700, reinstalled DO sensors, collected met.
| West Pond
2012-09-06 I arrived about 13:00 PDT with Cove. It was hot and sunny with a very light breeze from the west. Water was running at the west inlet but not at the east inlet and the water level seemed a little low (10cm?). Jaclyn and Laurie took water samples earlier and Kristin Byrd’s group was there making measurements. We calibrated the Li7700 (sn TG1-0223). We used a tank of Ultra Zero Air (1900psi) and a tank of 4.982ppm CH4 in air (950psi). We flowed the gas at a relatively high rate to wash out the cell space quickly. The last calibration was at Licor on 2012-01-19. RSSI was 69 so we did not clean the mirrors. Zero was off by 0.047ppm and span was off by 0.010ppm at 4.992ppm. The eddy system was reading: 2.0ppm CH4, 69RSSI, 377ppm CO2, 580mmol/m3 H2O, 43.8AGC, 28.2C, 350m/s SOS A little while later at the corn site SOS was 346m/s. I compared the digital output from the sonic with the value as recorded by the Licor data logger (see the screen shot below). These values agree so the 3 to 4m/s offset we are seeing in the data is definitely internal to the sonic. We fixed the tilt in the sonic due to the tilt of the scaffolding by putting four washers under the low side of the sonic base. It is now much closer to plumb. We reinstalled the two DO sensors. There is a mat of material not far below the surface of the water making it difficult to position the lower sensor and the correct height. Both sensors were reading about 1mV in the water. I pulled the top one out into the air to check it and it climbed slowly to about 37mV. Maybe the water is just that low on O2? We collected the met data that was missed last week. |
3 photos found
20120906WP_SpeedOfSound.jpg ( 2012-09-06 12:28:25 ) Full size: 1024x600
Sonic vs Licor SOS
WP_autocam_20120905_1915.jpg ( 2012-09-05 19:15:13 ) Full size: 1920x1440
Nice sunset with clouds
WP_autocam_20120906_1215.jpg ( 2012-09-06 12:15:02 ) Full size: 1920x1440
Boom folded for LI7700 calibration
8 sets found
Can't check WP_DO
1 WP_DO graphs found
14 WP_met graphs found
5 WP_flux graphs found
Can't check MBWPEESWGT_mixed
Can't check MBEEWPSWEPGT_cam
Can't check MBSWEEWPBCBA
1 WP_processed graphs found
No data found for WP_arable.