Ekman spiral solution Vs increased transport

[willaguiar]

Problem: Check the bottom blue and orange arrows below for the transport over the top 5m for MOM6. There are two issues there….
[a] The bottom arrows (representing total transport over the top 5 m of each simulation) shows that the 5mtop simulation also has stronger Southward transport. The stronger 5mtop Southward transport could bring more low-salinity waters to the shelf.
[b] in the 1mtop case the Ekman spiral is resolved at z<5m (all the smaller blue arrows), while the 5mtop it isn’t. The lack of spiral can make all surface fresh water to pile up on the shelf. In turn, solving the spiral can disperse some of these surface fresh waters, allowing to salinity to increase.

We want to test if either [a] or [b] causes the freshening of the shelf….

[willaguiar]

To test that I ran one additional short simulation (olive arrow)

Simulation (olive arrow): 5mtop, weak winds. It has a 5mtop surface cell, but the zonal winds were decreased by 4% to roughly match the bottom blue arrow of the 1mtop simulation. The difference from the olive to the blue simulation would then be mostly that the blue one solves the spiral. If this simulation has the same decrease in DSW formation as 5mtop (orange), then it is likely that [a] does not cause the shelf to freshen.

[willaguiar]

SWMT in the first year of each simulation

Below it is plotted the SWMT curves for the first year of all simulations (Same color scheme).
5mtop-weak-winds simulation have the same reduction in the SWMT as the 5mtop case, therefore it is likely that the slightly stronger total transport in the upper 5m (a) does not matter that much for DSW formation.

Off course, that is not a clean comparison, as changing the winds we change a lot of other stuff… but I guess it suggests that [b] it is likely the mechanism, not [a]. I am setting up another case with 1mtop and stronger winds to see if the results would agree.

How do people few about this? Does this seem like reason enough to reject a?