Archive for June 24th, 2011

BLOOD, SWEAT AND TEARS….

Friday, June 24th, 2011

Buenos días a todos !

Firstable I would like to thanks the invitation to follow learning and enjoying with all of you, great team. Secondly, I would like to congrat the SIlbo launching team for his incredible job. Third, dont worry about this title, since it is only simple metaphore of this particular, and fascinant, ocean domain. We have largely fought with the NW Mediterranean convective cell since 2007. They are the queens of the non linear effects of the ocean.  We call them the EPIDERMIC PORES OF GAIA.

However, if there is an example in the ocean of the term -CONVECTION- this, the N Atlantic domain, is simply -the Area-.. Our  Gulf Stream (RU27 mission highway), transports the heat to this NE area amd liberates it to the atmosphere. It avoids a strong deplection of the Temperture (SWEAT). Otherwise the hole area would be permanently frozen (SST filed today in the Figure 1).

Fig 1. SST Fields (NOAA/MODIS) in the NE Atlantic. 24 jun 2011.

However, there is another second and critic effect. The cold water (more salted and dense) sunks iniating the thermohaline circulation around the hole global ocean, transporting heat and chemical equilibrium. Finally it surfaces at the end of the belt, in the gulf stream again.  The veins and arteries of Gaia. (BLOOD). (Salinity field today in Fig 2).

Fig 2. Salinity fields NCOM. NEW Atlantic. 24 jun 11.

And finally there is another additional effect. The surface topography deplects and the strong atmosphere - ocean CO2 gradients determine strong changes of the CO2 partial pressure. When the convective ceell is active (INSPIRATION, cold water in the middle, strong negative sea surface height anomaly), it introduces a great quantitty of CO2 in the ocean. When the convective cell relaxs like right now (EXPIRATION, warm water in the surface, small difference of the dinamic topography) this CO2 is trapped by the primary producers to convert it in biomass. For that, it has to be associated with the vertical mixing during the autumn-winter (high concentrations of nutrients in the upper photic  waters). Ther is another supply of nutirents coming from the  thaw (?) of the ice during the spring-summer leg. (SSHa field today in Fig 3).

Fig 3. SSHa NLOM field. N Atlantic. 24 jun 11.

 

This primary producers sunk (TEARS), transporting M and E to the deeper ocean. Look the incredible concentration of the potential future "tears" in form of phytoplankton blooms in this area. We have got used to work in the intertropical belt of the 3 oceans, so recording concentrations of chla arising to 34 mg/m3 is really shocking, but fascinant (Fig 4). I would imagine to silbo when dive-climb the epipelagic domain (100 m) feeling like "indiana jones in the middle of the forest cutting at right and left to follow on !!" (:)).

 

Fig 4. N Atlantic garden. MODIS Chl a fields. 24 Jun 2011.

In spite of the HYPEREUTROPIC character of the North Atlantic domain, the convection determines another imoportant point that it is really important for this mission. The pathplan designed for SIlbo sails W of any Regional Ocean Model Domain of Europe (Mersea, Eseoo, NOC, Myocean..). That means (nothing new under the sun), that we would have to fly Silbo with global models (hycom,..) only. Layered in z levels or non layered, they reproduced (soft some inconsitences) to be goods with RU17, 27 and Cook missions.

A convective area (the kingdom of non linear effects) where good and solids RegionaOceanModels forecasting  sometimes fails, will be an incognite. However, as Nielsen posted some days ago, the signal of the gulf stream flowing toward the right side of the Silbo nose will be intesive and clear. the first months... We would have to look for the eastern side of the warm eddies, or the western side of the cold eddies: Stronger gradients, better currents to the South. Considering all the points before I assume and run the risk to present this (figure 5). The TOTAL current field. We have a good cold signal S Silbo, and he can sail the W border to find S oriented currents.

Figura 5. Total current NCOM field. N Atlantic. 24 Jun 11.

 

Finally, as COOK and RU27, Silbo is heading a liquid meccano (sic) again. The dynamic topography is not very intense (-20 cm, +20 cm) But it seems to organize  as usual. Conforming an incredible liquid meccano of cold eddies sorrounded of warm eddies or the inverse. At different meso and submeso scales (fig 6).

N Atlantic Liquid Meccano. 24 jun 11.

As always, force, wind, sea and honor all, and thanks again to my incredible ULPGC team.

Antonio G. Ramos, Division of Robotic and Computational Oceanography,

University of Las Palmas de Gran Canaria.

 

 

 

Communication Breakdown

Friday, June 24th, 2011

So you know when you're sitting by the phone desperately waiting for it to ring?  Hours and hours pass by as it gets later into the night and still nothing.  Sorry Mom and Dad... I think I finally know what I've put you through over the years.

Challenger 1 made it through its first 12 hrs at sea yesterday as it began making its way south.  However after its surfacing last night around 7pm local/11pm GMT, we lost communications with it until about 9 this morning.  Through my experience with gliders, not making contact for over 14 hrs usually isn't a good thing.  The concerned feeling didn't improve either after I checked the satellite coverage for the region.

 

[Back when I was working on the 27 mission, I devised an algorithm to make predictions on whether Scarlet would be able to call in.  Using Gpredict (top) I could track the Iridium Satellites that the phone in the tail of a Slocum Glider call in to with.  Combining the position of the satellites with the surface conditions of the water collected by the glider (middle) and the wave height forecast from oceanweather.com (bottom), I created a sort of Green, Yellow and Red light prediction method that proved to be pretty consoling when 27 wouldn't call in on schedule]

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Ben and our friends at Teledyne Webb then saved the day when they emailed us this morning explaining that everything with the glider is fine and that the reason for no comms was that the network and modem were down back home thus not able to receive Challenger 1's call.  So the glider then continued on with the way point it had been previously given until its next surfacing time when it called in this morning around 9.   After making a few adjustments to try and conserve battery power as best we could, Ben punched in a new way point and set it on its way.

-Nilsen