Field Notes
<--2017-07-14 13:10:00 | 2017-07-26 13:30:00-->Other sites visited today: Mayberry | West Pond | East End
Sherman Wetland: 2017-07-19 10:30:00 (DOY 200)
Author: Patty Oikawa
Others: Max Burnham
Summary: installed profiler on LGR, downloaded GHG tower data
| We arrived at 10:30am, it was sunny and windy. The cal gas tank was not open all the way so apparently cal gas hasn’t been running to the LGR. We opened it all the way and it shows 1500psi, 7 days ago it was at 1600 psi so maybe it ran for a few days before stopping—will need to look at data to see. I measured the cal tank tubing at 2.5m so I can reduce sampling time from cal gas from 5min to 2min, given a 12L/min flow rate. We installed a profile with a total of 3 inlets at 0.5 m, 1.5m, and 3m above the water. Water height=11cm above soil. I’m a little worried that the lowest inlet is too close to the water. I’ll ask Bryan about water table management at SW but looking at previous WT data it looks like the WT never gets above 30cm. The top inlet height is 5.05m. Distance between center of sonic and LGR inlet is 41cm vertical offset and 16cm horizontal offset. LGR is below and east of the sonic. We cannot remove the rotometer from the big pump or else the flow is too fast for the LGR so we couldn’t measure flow rates on the profiler. Instead we blew into the inlets and timed the response of the LGR. Response time for each inlet was <5s and tubing lengths are ~10m so the flow rates are high, probably a little less than 12 L/min. As we were working the wind blew the ¼†tubing off the boardwalk and we had to put 3/8†OD tubing on the inlets above 0.5m. I will switch these out later. We also installed filters and funnels to the end of each inlet with 20micron filter paper. I need to keep an eye on these as they will clog up quickly given the high flow rates. We still need to install a new filter to the top inlet, for now the Swagelok filter is still in place. Final program for the profiler is 2min on cal gas, 2 min on each inlet before switching to 2hr on top inlet. 2min on the inlets and cal gas gives >100s of true data which allows the LGR precision of D13C down to 0.1per mil. This will allow good calibration and hopefully good estimates for the keeling plot. We also checked the clock on the LGR against a cell phone and the LGR was 1s ahead. Finally, I downloaded fast GHG data from the tower. |
0 photos found
7 sets found
Can't check MBWPEESWGT_mixed
Can't check MBEEWPSWEPGT_cam
15 SW_met graphs found
4 SW_flux graphs found
Can't check MBSWEEWPBCBA
Can't check SW_Temp
14 SW_Temp graphs found
No data found for SW_arable.