Hi, I am looking for the list of co-located CTDs that are used to process data from oxygen sensors. Specifically, I am trying to figure out which CTD (METBKA or METBKB) was used to do the pressure and salinity compensations for the Aanderaa oxygen data collected on the surface buoy (1m ) of the a GI Apex SUMO.
Thank you,
Kristen
Hi Kristen,
If you look in the attributes of the associated salinity variable (which should be “met_salsurf”) you’ll see it has an “instrument” attribute which gives you the reference designator of the sensor it pulled data from. I’ve attached a screenshot of what I get when I downloaded a dataset from the oxygen sensor on the GI SUMO. It looks to be METBKA.
Thanks, Andrew! Following up on that instrument attribute is there a reason why the source for the ‘pressure’ variable in the DOSTA files is the ‘flort’ and the result is a ‘NaN’; Why isn’t the CTD pressure used?
For DOSTAs that are not colocated with a CTD, OOINet is searching for a pressure stream to associate with the dataset, and finding the FLORT pressure. That said, as I understand it, what its actually defaulting to for the value of P to plug into the correction is the nominal depth value for the DOSTA (not an issue for the buoy dosta). You see a similar thing with the DOSTAs located on the Flanking Moorings.
For the DOSTAs colocated and/or plugged into a CTD (the NSIF and those on the mooring risers at 40, 80, and 130m on the surface mooring wire) all utilize the “int_ctd_pressure” for the pressure correction
@fogaren
This prompted me to dig into this issue more and it looks like I gave you some bad info about the Flanking Moorings (the SUMO is still pulling the data from the METBK-CT sensor with doesn’t have a pressure sensor so its defaulting to deployed depth).
There IS a colocated CTD which is delivering the sea_water_practical_salinity and sea_water_temperature parameters to the DOSTAs on the Flanking Moorings. I’m not sure why the pressure stream is not being delivered and instead its defaulting to its deployment depth.
@areed Thanks for digging into the issue more. Let me know what you find. Thanks!
