Field Notes

<--2019-11-19 09:00:00 | 2019-12-13 10:00:00-->
Other sites visited today: Bouldin Alfalfa
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Bouldin Corn: 2019-12-02 11:30:00 (DOY 336)
Author: Daphne Szutu
Others: Joe

Summary: Tower had fallen over because of high winds, disassembled tower and brought all sensors back to lab, downloaded FD chambers

2019-12-02
Bouldin Corn

Joe and I arrived around 11:30 after Tyler texted us a photo of the Bouldin Corn tower laying on the ground.

It was an overcast and cool day and had been raining for the past 2-3 days. Our field was not flooded yet, but the field to the north was. Looking at the data back in the lab, the tower lost power around 19:00 on 2019-11-26. At that time, the 30-minute average wind speed was about 10 m/s, and the 20Hz wind speed was about 20 m/s. One fence post and the round radiometer boom were bent into an L-shape. The other structures looked ok.

We disassembled the tower and brought back all the sensors for testing. We left the scaffolding and eddy post there at the edge of the field. The power cable going to the tower had been yanked loose from the AC-DC converter. Joe cut off about 1 m of conduit to find the end of the cable and reconnected it.

We pulled the other end of the power cable into Tyler's data logger box and used it to power our three FD chambers with ~23V. I downloaded data from the three FD chambers.

Visible major damage:
- The 4-way radiometer has half of its sensors disconnected
- the sonic had one traducer missing (did not find it)
- 7700 spars were probably torqued - cracking visible on one
- PurpleAir was full of water from being upside down

Sensors removed and brought back to the lab:
Arable II sn C002445
Arable I sn A001359
Purple Air sn 68c63acc07a9
Decagon NDVI sensors sn 882103020, sn 2046503357
Decagon PRI sensors sn 897103002, sn 913003004
Stardot camera sn 0030F4D21491
PAR sensors sn 140441, sn 140453
Diffuse PAR sensor sn 140456
Soil moisture sensors sn M003370, sn 17133, sn 17129, sn 17128
Heat flux plates sn 11326, sn 10867, sn 10861
Water level sensor sn 70011234
DF Robot range finder sn URM06-001
Precipitation tipping bucket sn 65548-615
Barometer sn L2340502
Air T/RH sensor sn L1740395
CR1000 sn 66251
CR10x sn 31308
AM16/32B sn 21690
AM25T sn 7908
Three soil thermocouple profiles (bottom 1/3 of the rod was dry when I pulled them out of the ground)

Anemometer sn 074417
LI-7700 sn TG1-0155
LI-7500A sn 0042
LI-7550 sn AIU-0614

We left around 14:45 to go to BA and check on the other sites. All other sites (BA, WP, EP, EE, SW, and MB) had standing towers and solar panels. We did not visit SB, but Tyler visited the same day and did not tell us about any apparent destruction.

We plan to put the tower back up in the next week or two. Since we are planning on taking down East Pond next month, we will borrow the LI-7700 from East Pond for this tower (i.e., EP will not have methane data for the last few weeks of the year).

5 photos found

20191202BC_FallenTower.jpg ( 2019-12-02 00:00:00 ) Full size: 1600x1200
Bouldin Corn tower that fell down on during a wind/rain storm on 2019-11-26.

20191202BC_FallenTowerJoe.JPG ( 2019-12-02 12:41:56 ) Full size: 1920x1440
Joe taking off sensors from Bouldin Corn tower that fell down on during a wind/rain storm on 2019-11-26.