We’re back... and we’ve got gear.

Mooring Palooza

Mon, 8 Aug 2011 13:15:34 -0700

From Thompson: Cha-ba is repaired, NEMO-Subsurface is redeployed and working perfectly! We’re on our way home now. Here’s the update email I just sent:

All,

We're happy to report that Cha Ba is back in the water, successfully deployed at 2100 last night. The system has a redesigned power and battery system that should give it 4x longer endurance than before. We worked hard for 4 days to completely redo this complicated system - and even added a wind power generator!

Best of all, we didn't waste a second of ship time since the three volunteers aboard helped us collect a beautiful time series of T, S and velocity in Juan de Fuca canyon while we did so. We also managed to fill in some gaps in multibeam bathymetry for both Will Wilcock and the Olympic Coast Sanctuary folks.

The subsurface mooring component of this mooring system, which we call NEMO-subsurface, was also successfully deployed today and is working as planned, with data being telemetered back to shore using Cha-Ba as a relay to reach the coast guard antenna in La Push - and back to APL from there. This state-of-the-art system is delivering hourly profiles from 19-m to the bottom of T, S, O2, chlorophyll, vector velocity, and nitrate. We're really excited about these time series of continuous profiles. We may need to work with Emilio to get the subsurface data onto NVS; I can't recall where we were with that.

Unfortunately, the deeper inductive sensors are not functioning right now on Cha-ba - however this is much less of a blow since we will turn the full system around in October and they are nearly completely redundant now that the subsurface system is fully operational.

Thanks to all - this was a huge effort made possible by the availability of Thompson days at the end of Jim Mercer's cruise, and his willingness to let us use them - so a big thanks to Jim. Also, we owe thanks for the hard work and great engineering of Chris Siani, Mike Kenney and Paul Aguilar, and for their availability for a 5-day cruise on short notice. Same for Colin Smith, who was a huge help, so thanks to him and to Al for making his time available. The captain and crew of the Thompson were, as always, great. Last but not least, Shuang Zhang, a graduate student working with Jan and me, and the volunteers for standing CTD watches for 36 continuous hours.

From Revelle: All moorings are recovered! The gang there is now downloading data and resting after a harrowing few days. Great job to all!!!

Almost ready, we hope

Sun, 7 Aug 2011 09:12:13 -0700

Reporting from the Washington coast, we completed our CTD station yesterday morning and ran down 100 miles south to map out the seafloor for my colleague Will Wilcock, a marine geologist in our department. Meanwhile, we’ve been continuing to work on our buoy. We’re nearly done, but there are a couple of lingering mysteries with the electronics that we must solve first. Colin and Paul finished putting the new batteries in, and made some changes that will let us add new batteries in the future if needed, and also to charge the batteries without opening up the buoy.

I also added our wind generator, but we decided not to connect it to make sure it works well in the harsh marine environment. The fear is that if it flooded or shorted, it could drain the main battery packs, endangering the whole buoy rather than helping it.

We hope to redeploy the whole system later today.

Meanwhile, wavechasers west aboard the Revelle have safely recovered two more moorings, nearly in their entirety. They are asleep now (Taiwan is 16 hours ahead), preparing for two more moorings today.

Taking data while we work

Sat, 6 Aug 2011 07:00:04 -0700

Thompson and Revelle each cost about $30,000 a day to run. While we are very fortunate to have these days left over at the end of Jim Mercer’s cruise to work on our buoy, it would be unconscionable to just drift while we work. Thanks to the hard work of the marine technicians, three volunteers and graduate student Shuang Zhang, we’re taking an excellent time series of CTD and ADCP in 700 m of water inside a submarine canyon known as Juan de Fuca canyon. In plain English, that means we’re repeatedly lowering our instruments from the surface to the bottom. This will allow us to see the layers of the ocean moving up and down, while we measure them flowing back and forth. These together let us map out the flow of energy and turbulence up the canyon. (Remember: we’re interested in following the path and ultimate resting place of undersea “internal waves”; see earlier blog entries.).

Thanks volunteers, marine techs and students!!

By the way, Mike and Annie keep a blog of their own, at buoytales.wordpress.com. Check it out.

Watts and Joules and DC converters

Sat, 6 Aug 2011 06:56:00 -0700

Now it’s up to Chris Siani, electrical engineer, to replace the power-hungry components on the buoy with better ones. Chris and I have been working hard to determine the best strategy and have come up with several relatively simple modifications that reduce the power of the whole system from 8 Watts to less than 4. When you’re running off of batteries, determining the lifetime of the buoy’s a simple matter of dividing the battery capacity by the power (the rate at which we use them). So we’ve more than doubled the buoy’s life.

Problem right now is that our buoy data logger, which controls the meterological sensors, is not communicating with us and may be dead. Sigh. It’s always something.

R/V Thompson: recovering cha-ba

Sat, 6 Aug 2011 06:51:24 -0700

Our mission is to rescue Cha-Ba, our surface mooring, and to rewire its electronics to use less power. We’ll also swap out its batteries, which are dead, and add a wind generator to give it a boost. The first step was to get it on board, which we did cutely by grabbing the top part, the “business end”, and leaving the rest of the mooring in the water. Once we had the top part on board, we disconnected it and attached a dummy float to keep the rest of the mooring afloat while we worked on the top mooring.