Category Archives: Remote Sensing

SIO Airborne Flight (9/21/17)

SIO Melville lab had our last day of flying the MASS system yesterday. Again we experienced clear skies and windy conditions which provided good signal for our sensor suite. We flew an additional calibration flight after the science flight to wrap things up and spent the day today backing up data and packing up to head home after a successful campaign.


L to R: Surface wave modulation off Point Sal, strong wind and wave conditions again from Oceano to Shell Beach, our pilot Hank maneuvering us toward Mussel Rock.

Rip currents @Guadalupe

Graduate students Alex and Spencer have been capturing drone footage of rip currents along the beach by our radar site and comparing optical versus radar observations. Above left is a snapshot of one. Rip neck and rip head are evident by their entrained sediment. Rip head is particularly interesting  with its intermediate scale wave breaking and smaller scale instabilities along the outer edge. Sped up version of the movie (8x) can be viewed here. Above right, the GEarth radar overlay on the right pins the drone location just off the beach from our radar site. The green dots note the southeastern corner of the OSU Oceano array. The scale of these rips may seem a bit small (200-300 m cross-shore) compared to the cross-shelf distances you all have been covering with your ship ops, but don’t count them out yet!

You can check out a radar movie of the rip here, or on YouTube here. In the movie you can see at least a half dozen rip currents, even cooler, at 1541PDT on Sept. 11 you can clearly see a set of solitons crashing into the surf zone and into the rip currents. Afterwords there are interesting cross-shore dark features that we suspect are slicks of some sort.

  

Fighter pilots at the beach.

Oceanographers use this one weird trick to see internal waves!

Click-bait headline aside, we did see some fairly astounding internal wave characteristics in combing through the airborne IR data today. Specifically, Melissa and our pilot Dave flew a final transect along a bore front about 5 miles offshore Pt Sal and saw this:

The view shows an IR snapshot of a portion of an internal wave packet, looking perpendicular to the wave (offshore).  Relative brightness temperature (deg C) is indicated by the colorbar (warmer features are brighter).  The horizontal scale of the image is about 500m along the bottom edge and 1000m along the top edge, so the billow (instability?) structures with cool centers are about 200-300m in scale!  Here’s a link to a movie (37 MB) that shows about a minute of realtime flyby of this bore (?) front.  Lot’s to think about!

Photos from around Pt Sal from the air.

I wanted to share a few quick images of things we saw from the air today (it’s pretty amazing!). Times and general locations are indicated below.

Looking northwest from Pt. Sal out to the Sally Ride (1324 PDT).

Bloom and rips just north of Mussel Pt (1406 PDT).

Sally Ride transiting inshore of an internal bore front (1423 PDT)

scripps oceanography uc san diego