Salinity and vertical velocity in the 1/30-of-a-deg OFES snapshot

Figs. 1 and 2 show the vertical section of vertical velocity w and salinity anomaly, respectively, in the 1/30-of-a-deg OFES snapshot along 19°N. We see that:

1. There are events of injections of salinity into the upper ocean similar to those observed by Johnson et al. (2010; their Fig. 3c). The injections are both mesoscale and submesoscale. More work (and more OFES output) would be needed to confirm that the frequency of these events is consistent with the observed one.
2. Large vertical velocities, in particular those associated with submesoscale features, do not necessarily correlate with these injections of salinity.

Figure 1: Vertical velocity w along 19°N on Jan. 1, 2001 in the 1/30th-of-a-deg OFES model.

Figure 2: Salinity anomaly along 19°N on Jan. 1, 2001 in the 1/30th-of-a-deg OFES model. Values in w larger than 10 m/day are plotted with black contours.

Questions:

1. Are these events present in the 1/30th-of-a-deg OFES model?
2. If yes, can we understand what causes them in the model? Can we find an index that points to that process, an index that is computable from ARGO/AVISO data, and check that this index does also point to the salinity injections observed in the ARGO data?
3. If no, either study these events in a new simulation or use Andrei’s output model? In each case, verify first that surface-trapped submesoscale features, similar to those in the 1/30th-of-a-deg OFES snapshot, are also present.

NOTA: the salinity anomaly in the OFES simulation is quite different from the observations; although salinity keeps increasing upward in the observations, it decreases in the OFES model. The OFES model might underestimate the net evaporation-precipitation at the surface.