We’re back in the water off Oregon. Now we are in our winter sampling mode, where we get one out-in section and then recover at the first chance the weather gives us.
The outbound section shows a big slug of warm, (super) high chlorophyll in the offshore surface layer. This is may be associated with the icky HAB (Akashiwo sanguinea) that created a foam that dissolved the water-proofing oils from seabirds and was killing them as a result (http://www.oregonlive.com/news/index.ssf/2009/10/killer_foam_was_it_a_freak_eve.html).
Jack Barth and our Oregon shelf glider observations feature prominently on the NSF website (http://www.nsf.gov/news/special_reports/deadzones/index.jsp). The report describes how our continual presence in the Oregon coastal ocean via gliders has helped reveal the unprecedented extent and severity of hypoxia in the Pacific Northwest.
I was checking out the latest plots from SG130 yesterday, and I noticed a very interesting feature. The glider is a ways south of Newport, over 100 km offshore, heading northbound. In the last several profiles, in addition to a surface chlorophyll peak (~50 m), there appears a second chlorophyll maximum around 200 meters. Check it out:
Surface and subsurface chlorophyll signals off of the Oregon coast, Fall 2009
The feature shows up in the backscattering data, too, and is not associated with any change in water mass characteristics (temperature or salinity). Is the deep chlorophyll max (DCM) an older surface bloom that has been advected offshore and is now sinking out? It would be neat to look at the glider and satellite data going back in time to see if I could track the origin of this DCM. Time to hit the literature and refresh my memory on the coastal dynamics of summer phytoplankton blooms off of Oregon. Any thoughts from our readers on origins of this feature, and whether or not it is an annual occurrence? I’ve got SG130 data from last summer, too…
IMHO, if you name your glider Waldo, you are asking for trouble …
Let’s hope they find it.
Track line for glider sg158 lauched at the beginning of August
After performing a very nice “butterfly” pattern during the MOOMZ cruise, we sent sg158 offshore to start cross-shelf transects. Shortly after that, we started getting loads of roll retries and even a few roll errors – this means the internal motors were trying to shift the batteries and execute a roll to turn the glider and the motors either did not respond enough or did not respond at all. We panicked a bit a called Fritz at UW. He gently chided us for not digging a little deeper into the log files, and then suggested some glider magic:
Create a pdoscmds.bat file with these 3 lines and let the glider execute it during next phone call:
menu hw/pitch/read
menu hw/roll/read
menu hw/roll/rolls
This ran the glider through a series of tests on the roll mechanism. Things seemed ok, but the problem continued to worsen as we made more and more dives. Eventually, the glider was stuck rolled partially to the starboard side, meaning all dives now executed as a slow clockwise spiral on the way down and counterclockwise spiral on the way up with no real control of heading.
Last 1000 m dive from sg158 stuck rolled to starboard
Now, this meant sg158 had to be recovered. It wasn’t in imminent danger, but it was way (30+ nautical miles) offshore. Once again, Gadiel Alarcon sprang into action (on a Saturday and Sunday no less), and late on Sunday August 23 sg158 was safely recovered and brought back to Iquique.
On Monday, Laura emailed with Ruben Moraga at UNAP and they got sg158 turned off and stowed away. Now we’ll need to get the gliders shipped back to the US to replace sg157’s batteries and figure out what went wrong with sg158.
sg158 is back in the water off Iquique, Chile! Laura deployed sg158 on Saturday morning, which meant a pretty crazy piloting schedule: Anatoli was first, he got sg158 off to a good start, but then had to hand it over to me and Justin mid-morning. Things were going great until the internet on the Wecoma (OSU’s 185 ft research vessel – did I mention I was on the Wecoma for another cruise?) crapped out. Usually the Wecoma’s satellite internet connection is pretty dependable, except when you’re headed west (because the mast blocks the antenna), but we were headed east. Turns out one of the routers failed, but OSU Marine Technician Dave O’Gorman came to the rescue and fired up the spare. We were back on line and continued to pilot and tune sg158.
Right now sg158 is headed offshore, where it will start a butterfly pattern that it will occupy while the rest of the MOOMZ crew come out on the Vidal Gormaz and sample water.
Last Monday (7/13/09) we deployed SG130 around NH15 (Newport Hydrographic Line). Conditions were great – almost no wind and very small swells. Captain Mike took us out on the R/V Elakha, OSU’s trusty day-trip vessel. Here you see Justin and I easing the glider off of the fantail, with Mike’s help.
Easy does it - SG130 being deployed from the R/V Elakha.
If you want to follow SG130 during it’s mission, follow this link to the Glider Research Group web page. It will be traveling on a path that looks like a capital “E”, where the top of the “E” is the NH line, the middle line is a visit to Heceta Bank, and the bottom is an east-west line near the mouth of the Umpqua River. The last time that SG130 was deployed, we saw some very interesting patterns of sediment resuspension – I am hoping that we see the same patterns again.
Goodbye SG130 - see you in a few months. Stay out of trouble!
We continued to have communication problems with SG157, so we decided to call on our Chilean colleagues to help with a rescue on July 10th. The Seaglider was close to the coast at the time, so the pilot worked to keep it as close as possible to the port of Iquique despite a current pushing it to the south.
The plan was to have a student, Nadin, fly from Concepcion to Iquique to help with the recovery, since he helped us with the deployments and recoveries back in March. We communicated with our Chilean colleagues mostly via Email, so sometimes things were happening there faster than we could follow. It turns out that before Nadin could get from Concepcion to Iquique, the Chilean Navy was already on sight and recovering our glider! Jack’s words were, “Chilean Navy to the rescue!” We were all surprised that they had gotten involved, but I guess it’s not every day that a misbehaving Seaglider needs to be rescued off of the Chilean coast. We were (are!) very grateful for their assistance, and they did a great job on the recovery. By the time they got the glider back to shore, Nadin was able to get there and shut the glider off with the magnet. All’s well that ends well in the world of Seagliders!
We received this clipping from a Chilean newspaper yesterday (click for bigger)…
Chilean newspaper article on the SG157 recovery
We’re famous!
sg157 stopped communicating with the basestation sometime late last Friday (06/26/09). sg157 disappeared for 4 days, and then finally called in Tuesday evening. Anatoli and Justin handled it like pros, and figured out that the glider had happily continued to dive and receive GPS fixes, during it’s seclusion. This means there’s nothing wrong with the antenna and that the antenna is getting far enough out of the water. It also means that there’s nothing mechanically wrong with the glider.
The problem appears to be isolated to the Iridium satellite phone communications.
sg157 has been calling in more consistently since then, but misses a scheduled call in every now and then …
Out plan is to continue to fly sg157 onshore. If we get another big disappearance, then we’ll have to figure out an emergency recovery. If things continue to go OK, then we’ll send Laura out at the beginning of August to put sg158 in before the MOOMZ cruise, and we’ll send Justin out at the end of August to recover sg157.
—jack
Low oxygen (white contour) near the bottom across the Oregon shelf