A couple of MPC Oceanography students accompanied the MBARI team to recover the drifters yesterday. They quickly found both of them and brought them back on board. They were out for almost exactly 48 hours. After drifting south for the first 12 hours or so, perhaps due to strong NW winds that day, they turned and drifted north and west, along the expected counterclockwise rotation of surface water in Monterey Bay.
Here is a quick and dirty cut and paste job of their complete paths. I don’t have the software set up yet to make my own maps of their paths. These are from the AeroStar tracking website. They generally drifted from southeast to northwest.
We’re very happy with this first deployment of the drifters and thank the MBARI team of John Ryan and Erick Rienecker. The MPC students seemed to enjoy it as well. Four of the five we sent came back very enthused about the whole experience. They took some pictures, but I haven’t been able to get their pics downloaded onto my computer. Maybe we’ll see some next week.
So I’m thinking about how to integrate this stuff into my lesson plans for next week. I’m thinking of creating a short activity where we ask the question, “Did the tsunami affect the movement of the drifters?” This will involve the following aspects of data manipulation:
- Determining the time the Tsunami hit Monterey
- Making a hypothesis about whether or not the tsunami affected the drift
- Identifying exactly what we would see, and on what timescale, if the tsunami affected motion.
- Manipulating the Aerostar tracking site to find times and positions of data points
- Looking at the data to determine if the identified changes in motion did or did not take place.
The anticipated outcome is that the tsunami did not, in fact, influence the movement of the drifters. Hopefully, this will be a useful realization that wave motion and current motion can be totally different because they are totally different processes. We know, for example, in the northeastern part of Monterey Bay that the longshore drift of the sand on the beaches is in exactly the opposite direction (west and southwest towards Moss Landing) than the surface currents (north and west, as our drifters demonstrated). So it would follow that tsunami motion would not necessarily be detected, especially at the temporal resolution available to the drifters (one measurement every half hour).
I’ll share this if I get it going.
Over and out.