Ariane, Qin and Angèlica arrived at 9 UTC at the field site. It was sunny with some small cumulus clouds and a light breeze, and it was a relatively warm day.

We drove through the entrance on the west towards Muntells, and we used the chain at the entrance that we had not noticed last time. The cinder blocks were still at the site and we should tell Eurecat to pick them up when they visit the site.

When we arrived, we gladly found that the tower was working (the datalogger, multiplexor and sensors were on). We noticed some bird poops over the wood platform, the horizontal poles and the sonic anemometer. We also noticed the LI-7700 water reservoir was almost full.

1. Qin stick the colourful poles next to the SHF plates and added the split loom to the SHF plates cables.
2. In the meantime, Ariane and Angèlica downloaded the data, without deleting it from the USB. The size of the USB is 14.9 GB, and 13.1 GB of them were still free.

We stopped data acquisition for a few minutes while we cleaned the sensors.

3. We checked the readings before cleaning the sensors. The CH₄ sensor had an RSSI particularly low, 9%. Considered that the water reservoir was full, we guessed the cleaning method did not worked correctly during the previous weeks. We manually turned it on and realized the water was not well directed, and so it was not cleaning the lenses. However, since no water was wasted, we also guess that it was not even activated by the program. We later checked and the programme seemed alright, with the command of cleaning when RSSI is lower than 20%.

Ariane cleaned the gas sensors. The RSSI was improved up to 76% but could not reach 80%.

We did not make any changes to the program, and we will check when we go back again if the water reservoir is still full or if the cleaning method has been correctly activated.

4. Angèlica cleaned the radiometers and par sensors and added the split loom to their cables to protect them from the sun.
5. We reactivated the data collection and noted the readings after cleaning.
6. We synced the datalogger clock with the computer clock in UTC (we found it to be half a second off). We also manually synced the LI-7500 clock with UTC time using a clock from internet (it was almost one minute off, and so there was a warning at the app that disappeared with the syncing).
7. Ariane made sure the NR01 had all the screws in it
8. We added the missing screw at the met box for the ground cables.
9. We cleaned the solar panels, which were a bit dirty with bird poop.
10. We added one locker to the battery box.

 

We left the site at 10.30 UTC and headed to Eurecat. There we had lunch and a coffee and discussed with Judith which days we are going to go to the field again to install the Alfacada tower. We decided:

24^th of January: Ariane, Qin and Angèlica are going to set the scaffolding of the Alfacada tower with help from 2 Eurecat people from 10-15 local hour. Afterwards, the three of them are going to the Riet Vell tower.

7^th of February: Ariane and Angèlica are going to the Riet Vell tower.

21^st of February: Ariane, Qin and Angèlica are going to the Riet Vell tower.

6^th and 7^th of March: Ariane, Qin and Angèlica are going to set the sensors of Alfacada tower, and to check the Riet Vell tower.

We arrived to UAB at around 15 UTC and put all equipment and tools in the lab.

 

To-do and to-buy list:

• Add bird spikes to the sonic anemometer. We need to previously cut the spikes base to make it thinner.
• Buy putty dough to fill up the holes from the datalogger box
• Buy lockers for the biomet box
• Buy anti-theft screws for solar panel structure
• Desiccant for met and solar boxes
• Build thermocouple profiles
• Get a tool to clean solar panels
• Wash bucket
• Phenocam and camera enclosure
• Add colourful ribbons to the SHF plates sticks
• Check the wiring of the AM25T (vx channel)

Lectures from 09^th of January 2025:

	Before cleaning sensors	After cleaning sensors
LI-7500 readings
CO2 ppm	410	410
H20 ppm	359	450
T ºC	15.4	16
P kPa	101.8	101.8
SS %	98.5	99.7
LI 7700 readings
CH4 ppm	2.02	2.08
RSSI %	9	76