PacX challenge data

Benjamin, our second waveglider headed to Australia, has...

Fri, 15 Feb 2013 12:04:00 -0500

A beautiful day cruising the tropics

A category 3 storm right at the end of 2012

The route from Hawaii to Australia

Benjamin, our second waveglider headed to Australia, has arrived! On February 14, 2013 at 22:20 UTC, after over 9400 nautical miles traveled from San Francisco, he finally arrived in Hervey Bay Australia. He collected millions of data points and survived some really exciting storms.

With the arrival in Australia of Benjamin in the next days, is there any chance to see Fontaine Maru coming back to Hawaii in order to explore the PacX route to Japan ? Did you have some GPS information coming from the ghost Piccard Maru ?

Tue, 12 Feb 2013 12:11:52 -0500

Benjamin has almost arrived in Australia. Fontaine is back in the shop and has almost finished being refitted. Part of the reason to do PacX was to perform some experiments, and we’ve learned some interesting exotic metallurgy from Fontaine. We’ll get him back in the water as fast as we can. Piccard should follow shortly after.

The first of our 4 transpacific voyagers has made it to...

Sun, 25 Nov 2012 19:29:00 -0500

The first of our 4 transpacific voyagers has made it to Australia. After a hectic final dash through the East Australia Current, Papa Mau was picked up November 19th (the white line on the map). It got far ahead of the other waveglider headed for Australia (Benjamin) when the other took some damage to it’s solar panel, so we had it detour (the red line) through Samoa and have a pit stop at a beach resort - our repair technicians get the best business trips.

On November 24th Fontaine Maru, one of the wavegliders bound for Japan, was picked up and is on its way back to Hawaii. It’s going to get some repairs done before heading off again. Our thanks to the captain and crew of the R/V Kilo Moana!

Can you inform me of the ETA of the Piccard Maru and Fontaine Maru in Japan as well as the location they will be coming ashore. Thank you

Mon, 19 Nov 2012 12:13:00 -0500

Unknown. They’ve both had mechanical issues and are in need of some help :-( They both had some experimental modifications that hadn’t been tested on a long voyage.

Is the unit of the wind speed in m/s or in knots (Nm/s) ? When comparing a dataset coming from ERDAP database (transmitted unit is in m/s) and the same dataset downloaded from SLAB database (unit is in knots), this is the same value... even with a ratoi of 1.852 !!! The user manual of AIRMAR PB200 uses knots and MPH.

Mon, 19 Nov 2012 12:09:08 -0500

It’s in knots: the unit specification from the old ERDDAP database was wrong. It’s accurate to about 1/10 of a knot.

It has been two weeks since Papa Mau crossed the equator. In...

Tue, 31 Jul 2012 17:51:32 -0400

Equatorial temp. and O2

Temp., salinity, conductivity, O2

World salinity

It has been two weeks since Papa Mau crossed the equator. In light of this achievement, we’ve examined the data from his CTD (conductivity, temperature, density) sensor in order to investigate the physical properties of the water he has traversed over the past 28 days.

As you can see, the temperature has been steadily increasing as Papa Mau travels into the Southern Latitudes (note that patches of data are missing as energy from the solar panels must occasionally be rerouted). The CTD picks up the small changes in temperature between daytime and nighttime as a clear signal. As temperature increases, you can also see the water becoming steadily more deaerated. This phenomenon is also tracking the daily fluctuation of temperature. This is perhaps the strongest signal of any seen on the PacX voyage (with an almost linear correlation between temperature and oxygen solubility).

Salinity, and therefore conductivity, also increase with temperature (so far still no laws of physics broken on the PacX voyage). The salinity maximum found was 35.58 PSU’s, which is consistent with long term global measurements of oceanic salinity for this region.

All of this data is readily accessible at http://slab.liquidr.com/. Papa Mau is travelling well, and his sensors are still fully operational. Not bad for an 8,000 mile road trip!

Three of the PacX gliders are about to cross the international...

Mon, 30 Jul 2012 09:59:00 -0400

Three of the PacX gliders are about to cross the international dateline, or at least the +-180 degree line. As one reader pointed out (thanks Jacques!), given the way the dateline wiggles around, one has already made the transition. While crossing the dateline doesn’t have quite the historic ceremony of an equator crossing, it’ll still qualify the bots as, in the terms of the Navy, members of the Order of the Golden Dragon.

If you haven’t seen it before, the PacX status page at http://slab.liquidr.com/finishline/ has a good selection of trivia.

Equator crossing

Wed, 18 Jul 2012 14:04:00 -0400

Yesterday morning (July 17th) Papa Mau crossed the equator. The software survived the sign change with (almost) no hiccups :-) Benjamin should be crossing in a couple of weeks. To get a quick dashboard on the gliders, look here.

A Little More About Mid Ocean Phytoplankton Blooms

Mon, 16 Jul 2012 13:52:37 -0400

Papa Mau and Benjamin are still traversing an area of dense chlorophyll A concentration. As previously mentioned, the increased chlorophyll A concentration is indicative of a dense ‘bloom’ of phytoplankton, microscopic oceanic plants that are the food source for krill and other miniscule marine invertebrates, which in turn form the dominant food source for much of the marine fauna. The mechanics of seasonal algal blooms are much more complex than an occasional patch of phytoplankton randomly spawning in favorable conditions. Phytoplankton exist year round in the ocean, migrating with the currents and growing more profusely in warmer waters. Nearer the equator, their presence is stronger and much more stable, as water temperatures are higher and fluctuate less. This is why our northern pair of PacX gliders are not discovering as much phytoplankton.

These tiny, marine flora persist most constantly near the equator, where water temperatures are both the warmest and most consistent. A key reason for this is due to the angle of incidence of solar rays, which warm equatorial waters much more efficiently than that at the poles.

In a positive feedback loop, the increase in phytoplankton in the water increases its ability to absorb sunlight, further warming the water and improving the growing conditions for these plants. As less sunlight reaches past the phytoplankton bloom, a thermal gradient is formed trapping the warm, biologically active mix at the surface. This is the reason for the strong temperature spike seen upon entering the bloom.

Carbon sequestration is a popular concern. It has been shown that 1 gram of marine chlorophyll sequesters roughly 4 grams of carbon per hour (Ryther and Yentsch, 1957). Much of the carbon humans pollute is absorbed by the oceans, and much of that is done by the marine plant community. When eaten, the carbon is transferred to the fish and so on up the food chain, before top predators sink to the bottom of the ocean for longer term storage. In this way, phytoplankton is key, not just to sustaining life in the oceans, but mitigating the pollution created by the burning of fossil fuels. The processes surrounding these tiny plants must be understood more thoroughly in order to preserve them in a world of shifting currents and changing ocean conditions.

Currently, phytoplankton distribution is most efficiently tracked by satellite (Yoder et al. 1993), as demonstrated by our previously-posted satellite image.

Although satellite tracking can give an estimate of the distribution of phytoplankton, and point to the densest regions, in situ data serves to broaden our understanding of the oceanic conditions in these areas. Imagine a fleet of 100 wave gliders perusing the phytoplankton rich equatorial waters, mapping in high detail ocean currents, water temperature, salinity profiles, pH and even low-atmosphere weather conditions. Better understanding the relationship between all of these variables will greatly help to inform models and predictive strategies we will need to understand how the ocean, and its life, will change in the face of a climate being transformed by humans. There is no replacement for boots-on-the-ground research.

All life processes have an effect on our planet’s shifting climate. The oceans are critical to life. Let’s start to understand them much more thoroughly.

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References

J. H. Ryther and C. S. Yentsch 1957 The estimation of phytoplankton production in the ocean from chlorophyll and light data. Limnology and Oceanography Vol. 2, No. 3, pp. 281-286

J. A. Yoder, C. R. McClain, G. C. Feldman and W. E. Esaias 1993 Annual cycles of phytoplankton chlorophyll concentrations in the global ocean: A satellite view. Global Biogeochemical Cycles, Vol. 7, No. 1, PP. 181-193

There’s a new facility for obtaining data from vehicles....

Mon, 16 Jul 2012 12:51:00 -0400

There’s a new facility for obtaining data from vehicles. It’s much simpler than ERDDAP: it doesn’t support all of the file formats that ERDDAP does, it only allows data to be retrieved as CSV files. But it understands streaming and authentication very well - two properties that make it operationally fit better with the way our business and the wavegliders operate. It’s pretty easy to use: you go to http://slab.liquidr.com/fetch and select a vehicle, an instrument, a start time, and an end time (optional), and a “reuse style” and the website generates a URL for you. If you just click on the URL, the selected data will be downloaded and opened in whatever application you have set as your default for opening .csv files (OpenOffice, Numbers, Matlab, GNUPlot or Excel are the usual targets).

This URL is really useful when you’re doing scripting: you can use the URL to read the data from within your own application. In a unix shell script you’d probably use curl, in java you’d use new URL(…).openstream(). The “reuse style” option on the URL generation page becomes important when the URL is being used for scripting. It determines how the URL behaves when it is used more than once. The most commonly useful option is to have each use fetch only the new data.

It has all data from all vehicles. It should all be clean & correct… There is an unresolved question about dissolved oxygen calibration, and there are occasional GPS issues, but otherwise it should all be good.

To access the PacX data, use the login id “anon” and password “anon”.

A composite satellite image of Papa Mau's chlorophyll A bloom

Fri, 29 Jun 2012 15:13:03 -0400

Following up on our gliders’ discovery of the phytoplankton bloom, we have obtained a composite satellite image of the region from April to June confirming the results. This image gives a general awareness of the blooms, however ‘on-the-ground’ data gathering serves to greatly expand our knowledge of these events.

Combining satellite technology with in-water data measuring will enable us to learn much more than ever before about our planet’s oceans. Here’s to a data-filled future!

A Chlorophyll Bloom in the Equatorial Pacific

Thu, 28 Jun 2012 17:56:00 -0400

The open ocean is considered a barren desert, however little oases of life are known to propagate anywhere. Papa Mau recently encountered an increase in chlorophyll-A concentration on his leg between Hawaii and the first TAO mooring [6/20/2012 15:20:04 (UTC); 9.8106 lat., -167.6827 long.]. Benjamin, who was trailing Papa Mau by about 180 miles at the time encountered the bloom 6 days later [6/26/2012 15:40:05 (UTC); 9.7325 lat., -167.7568 long.]. An increase in chlorophyll-A is indicative of a greater density of phytoplankton, microscopic ocean plants that form the base of the oceanic food chain. Distance traveled since the initial response is over 300 miles, this bloom is extensive. The computer generated image you can see is a screen grab of the fluorometer response displayed in Google Earth.

Embedded is a graph of the raw data. Notice the per diem fluctuation of phytoplankton density as they alter their height in the water column (at night moving deeper to respire and at day shallower to better access light needed for photosynthesis). The fact that Benjamin is starting to see an overlapping cycle as he enters the bloom adds weight to the discovery.

The discovery of this bloom confirms studies that describe a relatively recent increase in phytoplankton blooms in the Pacific Ocean (Venrick et al. 1987). “Since 1968 a significant increase in total chlorophyll a in the water column during the summer in the central North Pacific Ocean has been observed. A concomitant increase in winter winds and a decrease in sea surface temperature suggest that long-period fluctuations in atmospheric characteristics have changed the carrying capacity of the central Pacific epipelagic ecosystem.”

In other words, our changing climate is affecting the activity of the fundamental base of the ocean food chain. This will have widespread consequences for the entire ocean ecosystem in the coming decades.

Typically, phytoplankton blooms occur when an unusual abundance of a growth-limiting nutrient (such as iron, phosphorous or, more typically, nitrogen) becomes available near the ocean, allowing for a greater density of organisms to coexist than normal. Changes to ocean convection and deep-water nutrient upwelling could be providing the extra nutrients to support such a phytoplankton bloom, along with temperatures more favorable to growth. Scientists have sometimes poured large doses of these nutrients into the middle of the ocean and witnessed a consequent phytoplankton bloom (Martin et al. 1994).

Embedded above are graphs of water temperature and salinity inside, and before coming across, the bloom. Water temperatures inside are significantly higher than outside. The concomitant increase in salinity is likely unrelated to the bloom itself; increased water temperature quickens evaporation, leaving behind higher salinity concentrations. The precise correlation of the different data sets is in itself fascinating to see.

An interesting feature of this data is the distinct boundary between ocean conditions within and outside of the bloom. Notice how Papa Mau’s temperature and salinity measurements rapidly spike when entering the bloom, and how 6 days later Benjamin records exactly the same phenomenon (particularly salinity). It is possible that the increased phytoplankton biomass and its respiration/productivity create a warmer patch of water. The two related processes of blooming and water temperature together form a positive feedback system in which the warmer water temperature creates a thermocline that traps that water and phytoplankton near the surface (warm water is less dense), thereby causing the water to heat further, enhancing the thermocline, and so on and so forth. This kind of feedback loop plays a large part in enabling mid-ocean blooms to propagate so successfully.

Data like that gathered by these two gliders is crucial to better understanding the life cycles and processes of the ocean in order to better inform conservation efforts, sustainable fishing, as well as a host of other applications.

Here’s to other, exciting, future discoveries!

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References

Venrick, E. L., McGowan J. A., Cayan, D. R., and Hayward T. L. 1982 Climate and Chlorophyll a: Long-Term Trends in the Central North Pacific Ocean. Science Vol. 238, no. 4823, pp. 70-72.

Martin J. H. et al. 1994 Testing the Iron Hypothesis in Ecosystems of the Equatorial Pacific Ocean. Nature Vol. 371, pp. 123-129.

Benjamin and Papa Mau are moving at a brisk pace towards...

Tue, 26 Jun 2012 12:46:52 -0400

Benjamin and Papa Mau are moving at a brisk pace towards Australia, traveling along with the Equatorial Current. Papa Mau is the furthest head, jogging due south to cross the Equatorial Countercurrent. They’re benefitting from more favorable currents than Fontaine Maru and Piccard Maru, bound for Japan, who are traveling through the middle of the North Pacific Gyre.

6 days after leaving HI, our Explorers have found hospitable...

Tue, 29 May 2012 11:28:00 -0400

6 days after leaving HI, our Explorers have found hospitable waters south of the islands. We came upon a wicked eddy approaching buoy 51407. The boys gave it a hell of a try before tacking the only route available for several days to navigate the waters safely. Current velocity charts such as this one from PacIOOS made the tack through 1-2kt westerly currents for several days far less stressful than swimming blind!

Fontaine and Piccard were turned WSW toward 51002 late this afternoon having cleared the inhospitable waters to their NW. They will press on NW to buoy 51003 after they are clear of the eddies to the north and continue their journey to Japan.

Currents in red are flowing at two knots
As for the black… off the charts!

Papa Mau and Benjamin will be heading directly to buoy 51002 first thing in the morning.

What is the ratio of buoy (glider) to sub-marine piece? Can there be multiple buoys to multiple submarines? Can buoys be used to intake air and supply to submarine? Can this be used as sea transport of goods? Can there be multiple layers 3-tier?

Fri, 25 May 2012 15:18:12 -0400

Firstly, thanks for your interest, you have very interesting questions! I cannot answer your question with certainty, but I imagine the Wave Glider’s underlying principle can be applied to many different configurations, although varying the design is not as easy as bolting these different pieces together. Getting this system to work with just one float and one sub was a feat in itself. Check out this clip of a glider in action! http://www.youtube.com/watch?v=0_X05oIUmDo

Linking two of them together would not really benefit us, we’d rather have more that are spread out than big linked system so that we can cover more of the ocean. Gathering multiple data points on each path is something we do to explore the margins of error in our sensor arrays, and to improve the accuracy and credibility of our data streams. Adding a third tier to the design would most likely add more drag than propulsion, but we do add tow-bodies to the glider to for gathering data at depth which makes a three-tiered system.

Transporting anything of significant weight would prevent the glider from operating properly. Note that current maximum velocity is approximately 2 knots, as speed is limited by the movement of waves, and navigation of currents. Even if you made the gliders much larger they would travel too slowly for shipping goods to be considered efficient. However, it is perfectly designed for gathering many discrete data points along a transect, which is what it’s used for! As a species we don’t currently know enough about the oceans, and that’s what our company is trying to change.

Follow us on twitter for the latest updates! We’re currently crossing the Pacific Ocean. http://www.twitter.com/liquidrinc

Here is some recent data from the Seabird GPCTD sensors aboard...

Thu, 24 May 2012 13:23:04 -0400

Salinity Measurements April 9th and 10th

Temperature Data April 9th and 10th

Here is some recent data from the Seabird GPCTD sensors aboard the PacX gliders. The above two plots show the gliders’ measurement of salinity and temperature over the past two days. There is a sinusoidal variation across both salinity and temperature with a clear frequency of 2 hours. Note that Papa Mau and Fontaine are in almost perfect phase on 05/09. The Wave Gliders appear to be traversing a salinity/temperature gradient and the frequency of the variations are roughly correlated to the lap frequency around the set of waypoints. Just one example of the fascinating data collected on this Pacific crossing!

16 hours post departure from Hawai’i… our Explorers...

Tue, 22 May 2012 17:29:00 -0400

16 hours post departure from Hawai’i… our Explorers are thrilled to be back in the hunt!

Piccard Maru has a slight edge. En route to Japan; beginning a new Guinness distance record challenge.

Papa Mau playing it smart (drafting Piccard for now). En route to Australia; beginning a new Guinness distance record challenge.

Benjamin coming on strong (stopped off for a Guinness at wp251… had to cover Guinness distance record criteria waypoint). En route to Australia; continuing to build on existing Guinness distance record.

Fontaine Maru is bringing up the rear (stopped off for a few Guinness at wp241… same Guinness record requirement). En route to Japan; continuing to build on existing Guinness distance record.

Special thanks to our MarOps team and several visitors from the main land who provided nothing short of spectacular care for our Explorers during their stay in Kawaihae. As much as the hospitality of the Big Island will be missed… our Explorers are excited about the continuation of the epic journey ahead.

Keep up to date with the groundbreaking voyage! http://liquidr.com/pacx/

Late yesterday the four PacX robots left Hawai’i, two on...

Tue, 22 May 2012 12:31:00 -0400

Late yesterday the four PacX robots left Hawai’i, two on their way to Japan, the other two on their way to Australia. Their time in Hawaiian waters was longer than expected: we put a lot of effort into making sure that they were tuned up, calibrated, and well prepared for the second halves of their journeys. If you look at the data in the repository, you’ll find that it still has “issues”. I’m working on it. (still!) The data for Benjamin and Piccard Maru is fine, the data for Fontaine and Papa Mau is broken (the Iridium modems on those two robots got swapped out, which the old software feeding ERDDAP isn’t accounting for).

Fontaine Maru is not in Sunnyvale

Wed, 18 Apr 2012 13:42:42 -0400

Only its brain is :-) we swapped out the command-and-control unit and shipped it back to Sunnyvale. Fontaine is happily in Hawaii running with a transplanted brain. The old brain is being worked on in Sunnyvale. The software generating the data that goes into ERDDAP currently doesn’t track changes in vehicle ID numbers (we currently use the IMEI number from the Iridium modem). Yet another thing on my to-do list :-)

What is the GPS update rate for the gliders? Does it vary or do you keep a steady schedule? What do you use to monitor the weather patterns that the gliders may encounter? Is the speed data that you get from the gilders an average or an instantaneous speed? The data is great, keep it up!

Wed, 11 Apr 2012 17:35:13 -0400

The GPS sensor updates every 5 seconds, but we only send back GPS coordinates every 5 minutes, this can be reduced if we’re trying to conserve power or increased if we want to track the gliders more closely.

We use satellite data to monitor weather patterns but this generally doesn’t affect our course since we want to test the vehicles’ abilities in a variety of sea-states and weather conditions.

The speed data is a one minute average and the latest value is reported.

Glad you’re enjoying the data! Have you considered using your research and analysis to enter the PacX Challenge Prize for six months of free Wave Glider time and a $50k sponsorship from BP?

-DM