Greetings from the Central Coast of California. This is my first attempt at blogging, so I hope I do it right. From what I’ve read on other blogs, I think I’m supposed to record my stream of consciousness and try to stay somewhat on topic. We’ll see how that goes.
In an effort to kick-start our drifter program out here on the shores of Monterey Bay, I went and visited Jeff Paduan at the Naval Postgraduate School. Jeff had to put me on a special list just to allow me to walk onto the grounds of NPS. Jeff is the local HF radar guru and has written papers on the circulation of Monterey Bay. Jeff is PI for the Central California component of the Coastal Ocean Currents Monitoring Program, perhaps better known as COCMP. The COCMP website has a nice pdf brochure imaginatively entitled the COCMP Reference Guide (How Ocean Current Mapping Works and How it is Useful) (image at right). It has some nice information that would be useful for teaching students how the HF radar works as well as beautiful color photographs of HF radar antennas in some of the most stunningly picturesque locations in the world. Strangely enough, the best images of Jeff’s HF radar ocean current data are at his Central California Currents page. Here’s what the currents look like for today in our area:
Those circular patterns you see in Monterey Bay on the image on the right are not tidal. They have a 24 hour periodicity and form in response to offshore and onshore breezes that cycle back and forth throughout the day.
Jeff and I talked quite a while about HF radar and I learned quite a bit. I still can’t explain all the intricacies of which frequencies they use to get the best Doppler Effect and why, but at least my eyes won’t roll too far back in my head next time we go through it.
We also talked about “typical” ocean circulation patterns in Monterey Bay. The image below is from one day back in 1994—exaclty 15 years ago from our drifters workshop.
The image shows ocean currents layered over sea surface temperatures. It shows the typical counterclockwise circulation in the bay and the clockwise eddy just outside the bay. As was true on this day in 1994, the northeast portion of the bay is the warmest, and this water is pulled out into deeper water by the currents.
I looked at some of the drifters that Jeff uses in his research. They’re commercially made by Pacific Gyre. They have a floating sphere that contains the transmitter and then a sail system that opens up like an umbrella.
The next stop in my tour of ocean current researchers was the world famous MBARI, the Monterey Bay Aquarium Research Institute, to visit Erich Rienecker and John Ryan. Erich is one of the marine technicians and John is a researcher specializing in phytoplankton blooms. Here’s John and I looking at some eye-popping data on John’s computer. I was just blinking, I swear.
Here’s that eye-popping data John and I were looking at:
The left image shows satellite-generated data for chlorophyll in the water, whereas the right image shows sea surface temperatures. Clearly there are other factors besides just temperatures driving the magnitude of plankton concentrations.
The last week in September and the first week in October, John and Erich will be involved with an intensive data gathering effort in this area involving satellites, AUVs, moorings, and………..drum roll please……… OUR DRIFTERS!
On Monday September 28 and Monday October 2 we’ll send students out on their cruises to deploy our drifters and launch their AUVs among other tasks for this study. Later in the week, we’ll send students out with them to try and retrieve the drifters. Should be fun, and a great experience for the students.
Back in the classroom, we’ll be following the progress of the drifters on the computers. Hopefully this will set the stage for increased interest in learning about atmospheric circulation and ocean currents. Then, in early November, we’ll take the whole class out on a cruise and release one of the drifters once again (assuming all goes well with the MBARI guys).
Over and out,
-Fred