Field Notes

When: Date: 7/2/2008 , Day: , Watch Time: .

Where: Sherman Island Methane Study

Who: Dennis Baldocchi and Dimmie Hendricks

Weather: clear, windy and mild temperatures. There has been lots of smoke in the region last week due to hundreds of fires across California. Luckily the methane sensor was in the shop during this period

Phenology

Pepperweed is in full blossom. The plants came back after mowing.

Lots of ticks on the weeds

Tasks

1. check and download data at Sherman Island
2. Take TDR soil moisture readings
3. take spectrometer reflectance reading
4. Sample additional water Table ports
5. Sample LAI and plant height

Visited the new Twitchell Island field site with Frank Anderson and Lisamare Windham from USGS. The site looks good for rice and tules.

Showed them this field site too.

Main task this pm was to re-install the methane sensor. It had been taken in to LGR for maintenance and cleaning. The mirror time is up to 18 microseconds. We calibrated it in the lab with the noaa cmdl 1897.8 ppb standard.

Re-installed the tubing. The line is a bit shorter, so we need to re-check the time constant and lag. Put the 2 micron filter down stream from the 2 gravity water traps. This intent is to keep water out of the filter and keeping it from muddying up in the winter. The tubes and filters were cleaned before hand ( I think) by Matteo.

Sherman Island Pasture Site

1. Fence and gate power: v.
2. Datalogger Solar Panel and Batteries: v;
3. Reading from Gillsonic screen before downloading data. (The value of H₂O and CO₂ should be in the range of 0 – 5 v.)

3. 1. Methane Sensor
   2. Cell Pressure (near 159 Torr?):_142 torr; 160 torr at low flow_
   3. Cell Temperature: ____
   4. Time Constant:_18.2 microseconds
   5. Double Check

i. Sample rate: 10Hz?:__yes__

ii. Methane ppm Hi flow:

iii. Methane ppm, low flow (remember to put back in high flow:

iv. Pump status??:__ok__

v. Filter Status:___clean___

vi. Check Water in tube:clean

Connector to scroll pump was found in a broken state. I connected the hose with wire tie.

4. downloading data
5. If Swapping Li-7500 Analyzer. (Remove SN# ; install SN# )
6. Check the fans of air temp. and relative humidity sensors
7. Check MD-9 system connections
8. Check CR23X with two multiplexers and sensor values
9. Check levels of Radiation sensors, clear up surfaces.