3 month milestone since the deployment of the first batch of Argo Floats: status of the fleet

Last November we sailed from Puntarenas onboard the ship Kiki all the way to the Thermal Dome off-shore Central America.

Here we deployed 3 different types of floats:

• 1 Deep-Argo float (WMO/ID 2903880): measuring pressure, temperature, salinity and dissolved oxygen; cycling every 10 days with a parking depth of 1000m and a profiling depth down to the sea floor.

• 1 Core-Argo float (WMO/ID 2903800): measuring pressure, temperature and salinity; cycling every 10 days with a parking depth of 1000m and a profiling depth of 2000m.

• 1 BGC-Argo float (WMO/ID 1902692): measuring pressure, temperature, salinity, dissolved oxygen, nitrate, chlorophyll fluorescence, suspended particulate matter, pH, and light irradiance.

With the most complex one, the BGC, has the possibility of attaching other devices to the float. In this case, we clamped a passive acoustic sensor in the external body together with a ballasting foam in order to adjust the overweight in water (equal to 1.2kg). This sensor was programmed to record data continuosly since it has an autonomous memory and the battery is estimated to last up to 180 days. It's depth range is equal to 500m and is equipped with a pressure valve.

Since the floats are supposed to go all the way down, then up at a parking depth and all the way up to the surface to transmit all the data into a satellite in order to complete one dive. Until now, we've recorded more than 14 dives on different days (see below):

• 3/11/2024 (2 dives): one down to 60m depth, one 150m depth, correct functioning

• 4/11/2024 (4 dives): down to 380m-420m depth, correct functioning

• 5/11/2024 (4 dives): down to 380m-420m depth, correct functioning

• 6/11/2024 (4 dives): down to 400m depth, correct functioning, then stay at parking programmed during 4 days

By January 18th 2025, the BGC-Argo standard cycling parameters have been set up on with a cycling period of 10 days, profiling depth of 1000m and parking depth of 1000m. To date, the float shows a proper functioning.

So to sum up; The Core-Argo and Deep-Argo floats have collected 9 profiles each, remaining inside the Thermal Dome. The two floats dribed north then returned south in the surrounding to the deployment area. Up to now, the two missions are successful.

 

On the other hand, the BGC-Argo float dribed north and reach the continental slope offshore Guatemala. The float leb the Thermal Dome so it's necessary to recover that float and transfer it inside the Thermal Dome again.

Overall, all of the above conclusions are amazing news for the first ever Argo Float Mission in the Thermal Dome, we're really excited for what's coming soon with these new devices and all the data we will obtain!