In the previous post we presented the first dye simulation that Nirnimesh has done.  That simulation was for a release that totalled 2 hrs.  Now, Nirnimesh has performed an identical experiment for dye released for 6 hrs and compared the two.  The modeling details are the same:  This is with the COAWST model that couples waves and currents and has a 20 m grid resolution.  This simulation is for a period of time in Fall 2014 with northward winds.  Nirnimesh also sent in waves with significant wave height of 1 m, peak period Tp=14 s, and offshore angle of 200 deg.   He did two dye releases separated by about 3 days.

* Left panel is temperature anomoly (subtracting T=18 deg C), Right panel is dye concentration (ppb) in log scale.

* Each frame is one hour. The counter (dT) indicates how long since the dye release.

* About 100 L of Rhodamine WT was released over 2 hrs for each release.  This is a realistic amount of dye to be released.

* Green square is dye release location, Magenta dots are planned instrument locations/

* Both dye releases are at high tide.

Now the movie above is for surface temperature and dye.  It does not address the question of what dye does in the vertical.  ROMS works in vertical layers called sigma layers.  Each sigma layer fills up a part of the water column.   Below is a movie of the dye field on different sigma layers.   Note the differences between near bottom (left) and surface (right) panels!

Also, it is important to remember that in each movie the depth z varies on the sigma layer.  The way it works is that z = sigma * depth.    So the panels go from bottom to surface from left to right.   But they are not  fixed depth levels.