Please consider Figures 1, 2, 3 and 8 of PerlinEtAl05.pdf These are taken as a ship steamed back and forth repeatedly across the line pictured in Fig 1. The winds are indicated in Fig 2, and the response of the coastal ocean are shown in Fig.3 The left hand column is the N/S velocity across the transect, blue means flow to the south.
Q: What direction does the wind predominantly blow, and what direction does the water predominantly move?
Q: The wind slackens near 85h. What happens to the current? How quickly?
Q: Hypothesize why the current moves the way it does.
Q: Recall in Mixing.pdf where we calculated the time scale for diffusion of momentum. How long would it take for a momentum change of 1 m/s to diffuse to the sea floor if the viscosity were molecular (nu = 1e-6 m^2/s)? What if it were moderately turbulent (K = 1e-3 m^2/s)?
Q: What is happening near the sea floor? Why?
Q: What other patterns do you see and wonder about?
Consider the data plotted in SurfaceCurrentsAll.pdf. The First 12 pages are monthly plots of surface properties:
a) Sea surface winds - arrows indicate magnitude and direction, color represents magnitude.
b) Net heat flux - negative means the ocean is losing heat.
c) Surface currents - arrows indicate magnitude and direction. shading represents magnitude. These panels also have sea surface elevation contoured in 25-cm intervals.
d) Sea-surface temperature.
I found the arrows hard to look at in c) so I replotted in the last two pages images of the N/S and E/W currents respectively. Red-ish is to the N or E, respectively, Blue-ish to the S or W. Again, sea surface height is contoured on top.
Q: Pick out 2 or 3 patterns you can see evolving in each of the panels as the year progresses. Which properties change the most?
Q: What features dominate the sea-surface currents?
Q: Speculate on how you think each data set is collected?