Field Notes

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Other sites visited today: Gilbert Tract
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East End: 2024-08-29 11:40:00 (DOY 242)
Author: Joe Verfaillie
Others: Daphne, Arman, Kuno

Summary: Collected data, added half-frame to raise tower top sensors, Swapped RH/T, removed duplicate Pi-cam, Chamber measurements along boardwalk to the north.

East End
2024-08-29

Daphne and I arrived at 11:40 PST. It was sunny and warm with a westerly breeze above the canopy. Arman and Kuno arrived shortly after us to do chamber CH4/N2O/CO2 measurements along the boardwalk just north of the tower and later at West Pond. The water quality tricorder they were using stopped working. Arman went to get batteries for it but that was not the answer. So less than ideal measurements.

Daphne and I worked on adding a half section of frames to the tower to get the tower top measurements above the canopy that has seriously encroached on the sensors in the last couple of years. Daphne collected all the regular data first: met, flux, camera, salinity and minDOT. She swapped the desiccant in the miniDOT. The water level was 60cm.
The 7500 read: 405ppm CO2, 575mmol/m3 H2O, 26.9C, 101.1kPa, 98SS - 98 after cleaning
The 7700 read: 2.1ppm CH4, 55RSSI - 73 after cleaning
The eddy clock was adjusted from 16:58 to 16:53 and logging restarted.

Salinity was
Surface, 240.4uS, 16.4C

The plan was to attach pipes with crossover fitting as guides and supports. Then to incrementally lift the railing section on top with all the sensors attached until it was high enough to insert the set of half frames underneath. We added a second data logger box thinking there would not be enough slack in the cables. We disconnected all the cables that went to the tower top. We added two extra boardwalks one at mid height and a second one on top to make it easier/safer to work. We started to lift the railings and decided it was going to be difficult, slow and maybe unsafe so we moved to plan B. We removed the radiation boom. The four bolts holding it in place were pretty rusty but I got them to turn without breaking anything. Then we attached the long-side railings to the support post we added. With the long sides supported we could lift off the short end railing, replace it with the half height frame and put the railing back on top of the half frame. We left all the eddy sensors and tipping bucket attached to the other railing and did the same. We added the cross braces to the half frames, moved a boardwalk up to the new top height and put the long-side railings back in place. Then we reattached the radiometer boom. This ended up working really well in that we didn't disturb any of the instrument mounts so all the sensors are back in their same locations, orientations and levels but just an even 93.5cm higher.

After we got the scaffolding back together we discovered that most of the cables were long enough that we didn't need to move the data logger and AM16/32 mux. It might be nice to have the data logger in the higher box but we didn't really have time to do that. We did sort out the rat's nest of wires. The 7700 power cable had a spice that looked like it was about to fail which we cut off. That power cable and the ones for the pi-cam and RH/T fan are too short so they went to a new power strip in the new box.

The HMP60 sn L1740420 has finally died so we replaced it with a HYGROVUE sn E5905 in a new solar shield. The mount screw striped the threads from its hole in the solar shield so the HYGROVUE is held in with cable ties for now. The cable on the HYGROVUE isn't long enough either so there is a screw terminal in the new box to extend it to the data logger below.

We remove the older pi-cam sn RPI0W-005 because it's in a lower position and has a box that is hard to open. The newer pi-cam is still on the 7500 post but we moved its DC-DC converter from the data logger box to inside the box with the pi-cam.

After everything was put back together the only thing that didn't seem to work was SHF #1. Nothing related to that changed but Daphne rewired it to the next mux port and it seemed to be working again. The CR1000 program was updated for this and the RH/T sensor swap.

We jostled Mel's bird call recorder and camera on the upper railing.

Still need to raise the solar panel scaffolding too.

We left at 17:10 PST. We dropped off a pair of long pipes at the West Pond gate for tomorrow. We were so late leaving that the gate was closed. Luckily the combo hasn't changed, 2121 on the gold lock with black tape.

1 photos found

20240829EE_ScaffoldingRaisedCompare.jpg ( 2024-08-29 00:00:00 ) Full size: 1368x837
Before and after photos of adding a half frame to the East End tower