The world’s oceans are continuously monitored by drifting, profiling instruments known as Argo floats. The Argo program has grown from initial deployments in 2000 to over 3,000 floats today. More information can be obtained at the Argo Information Center. Raw data from these floats, typically temperature and salinity as a function of pressure, are available at two international Global Data Assembly Centers (GDACs): one at FNMOC, the other at IFREMER.
The APDRC produces products based on individual profile data. These products include gridding in both the horizontal and vertical as well as derived variables.
The APDRC accesses Argo data daily from the US GDAC and produces a variety of products. Most are updated monthly, but a few are updated daily. The products are based on different analyses defined as follows. It should be noted that not all variables are available in all products, that there are a variety of temporal resolutions (e.g., monthly mean, seasonal mean, etc.) specific to each product, and that products can include multiple analyses.
Data Product Table Click on ✔, to access the data product.
|1. Variables at each float location interpolated to standard depths||✔|
|2. Variables at each float location interpolated to isopycnal surfaces||✔|
|3. Derived quantities at each float location (mixed layer depth, isothermal depth, etc.)||✔|
|4. Derived quantities at each float location (surface and deep velocities, aka YoMaHa)||✔|
|5. Horizontally-binned variables into 1°x1° and 3°x3° squares, interpolated to standard depths||✔||✔||✔||✔||✔||✔||✔|
|6. Horizontally-binned Monthly mean variables into 3°x3° squares, interpolated to standard depths||✔||✔||✔||✔||✔||✔||✔|
|7. Horizontally-binned variables into 1°x1° and 3°x3° squares, interpolated to isopycnals||✔||✔||✔||✔||✔||✔||✔|
|8. Horizontally-binned Monthly mean variables into 3°x3° squares, interpolated to isopycnals||✔||✔||✔||✔||✔||✔||✔|
|9. Horizontally-binned Mixed Layer into 1°x1° and 3°x3° squares||✔||✔||✔||✔||✔||✔||✔|
|10. Horizontally-binned Monthly mean Mixed Layer into 3x3° squares||✔||✔||✔||✔||✔||✔||✔|
|11. Horizontally-binned Velocities into 1°x1° and 3°x3° squares||✔||✔||✔||✔||✔||✔||✔|
|12. Horizontally-binned Monthly mean Velocities into 3°x3° squares||✔||✔||✔||✔||✔||✔||✔|
|13. Horizontally-interpolated variables onto 1°x1° grid on standard depths||✔||✔||✔||✔||✔|
|14. Horizontally-interpolated derived quantities onto 1°x1° grid on standard depths||✔||✔||✔||✔||✔|
Information on the optimal interpolation scheme and derived products can be found [HERE]. In brief, data were interpolated in space using a Variational Interpolation (VI) algorithm. The principle of the VI technique is to minimize the misfit between the interpolated fields defined on a regular grid and the irregularly distributed data, so the optimal solution passes as close to the data as possible. The IPRC Argo product also provided LAS/OPeNDAP/DChart access with the documentation.
Information on the velocity files from float drift can be found in YoMaHa-07