http://fb.me/vX1v5eJZ

Atlantic Crossing: A Robot’s Daring Mission premieres today at the Blue Ocean Film Festival! http://fb.me/Gz0WSqiG

Atlantic Crossing: A Robot’s Daring Mission premieres today at the BLUE Ocean Film Festival! http://fb.me/HWMWjT24

http://fb.me/EzKCSnoT

http://fb.me/ERXCBide

http://www.nature.com/news/2010/100728/full/news.2010.379.html http://fb.me/EsZ1Rkrv

http://fb.me/CLc1zY4E

http://fb.me/FA9c9bzI

Hey all

just before dissappearing, Cook, the brave droid, was investigating the heat transport on the 26.5 N segment. However, SSHa fields posted by the students/scott/ulpgc also showed that Cook flied a fascinant segment of some -engaged- gears where the current forecast data sets seemed to agree and to disagree periodically.  Thus, our brave Cook gave some good opportunities to do some data assimilation experiment/comparisons (Figure 1) like this shown in the post.

Figure 1. SSHa showing the data assimilation segment from 59 to 53 W (1 jun -7 jul 2010)

 We compared 3 data sources: NCOM, NLOM Global model current data (1/8º and 1/32º respectively) VERSUS the drift current field calculated by Cook during the surfacing-diving stint period. Thus, using the speed and direction of both global models we evaluated the forecasted diving lat-long 12 min after (when diving) (Figure 2). 

 Figure 2.- Ground true Cook´s current  VS ncom/nlom forecast.

 Results show some fascinant findings (figure 3). We found 16 BAD disagreement (red colour) in 35 days (14 NCOM 1/8º and 10 NLOM 1/32º). The scale seems to affect the data agreement between them (some strong dissagreements in direction and module between both NLOM and NCOM data). It could be explained by the different data scale resolution (12*12 km2 vs 3*3 km2), NLOM data are able to target submesocale features while NCOM could not observe them, since the scale for targeting would require data sets down or equal of 6*6 km2.  Results also showed that these disagreement/agreement segments affect to different areas/periods.

Figure 3.- Rose of currents NCOM (violet) and NLOM (blue) in 3 stints.

It looks to keep a periodic oscillation of the errors… In some cases (second stint)  it looks to exist an strong disagreement between both directions and over/sub estimations of the module. The best sting /(undoubtely) is the third (the last 2 weeks).

The periodicity also seems to be preliminary explained in the figure 4.  Data seem to to show why this periodicity. The southern part of the 2 MESOSCALE GEAR seems to generate the strongest variation. Especially in those areas with a strong SSHa gradient.

Figure 4. Current roses error areas and the SSHa landscape.

 And finally (figure 5) the hole COOK stint (look that data assimilation began at 59 W). Global data seemed to agree (green/orange) by different periods/areas,  at the beginning, but especially, at the end when Cook flied the 53s W.

Figure 5. Cook pathway. Data assimilation of this blog began in the 59 W.

I expect you enjoy that. It is only a modest contribution honouring Cook and his incredible job at sea. THANKS Cook !!!. And thanks to the people of the other side (RU, under and postgraduated students, ioos,webb, navy, noaa.. ), and to the people of this side (PLOCAN, qualitas, PE). Reasons are obvious: your inmense job.

Finally let me thank my great ULPGC team/colleagues/FRIENDS, Jorge, Enrique, Dani, Josep, Pep and Alex.  I have forced the machine (a lot !)  to have this. But I understood that a data assimilation comparison (3 scales) with a glider in the middle of the 26,s N Atlantic big blue was an inedit opportunity.

Honor all,

Antonio G. Ramos

As of 7/7/2010 at 14:37 Cook has been missing in action. It has been 170 hours since Cook last called. We have talked to Webb and they don’t see any scenario where it will come back. We currently have no indication why we lost Cook.

Cook was out for 108 days, and was about 350 km from where Drake went down after 104 days last year. We are examining possible causes for Cook’s loss and seeing if there is any correlation with Drake.

Cook was a brave droid who died in battle. He collected excellent data which we will continue to analyze.

We’d also like to take this moment to thank our partners in Spain. Your forecasting and analysis have been incredibly critical while piloting the glider. We’d like to thank you for your time, effort, blogs and Skype sessions. Working with you on this mission has be an honor and a joy. We look forward to continuing our relationship in the future.