11 meeting of the International Argo Steering Team Scripps ...

Until now, it was possible to define two zones with different vertical sampling resolution: a
deep zone and a shallow zone. The transition depth (500 dbar for instance) and the bin size (25
dbar in the deep zone below 500 dbar and 10 dbar above) are defined by the user. It is now
possible to define a third zone near the surface with high-resolution sampling (1 dbar bin
average for instance). This will be implemented on 14 Arvor floats.
Three Arvor prototypes have been deployed in 2009 and have successfully achieved their
missions. Two are still active and should have completed 200 cycles by end of March. A
commercialisation licence should be established in 2010. The overall objectives of the ARVOR
floats are: 250 cycles at 2000m, continuous pumping for the CTD, 110 points transmitted by
cycle.
The Iridium transmission has been implemented on 2 Arvor floats. The first float (WMO
6900794) has been deployed in the Med Sea from the TARA (collab. with OGS) at the end of
2009. 99 cycles have already been done (1 cycle/day). The float transmits 2 dbar bin-averaged
data and 1 spot sampled triplet at 2 dbar. The downlink communication has been successfully
tested as well as the grounding procedure. The second float (WMO 1900848) has been
deployed in the Adriatic in Feb 2010. 5 cycles have already been done (1cycle every 5 days).
The float also transmits 2 dbar bin-averaged data and 1 spot sampled triplet at 2 dbar.
Two ARVOR floats with ARGOS 3 transmission are in construction by NKE. The floats should
be deployed in 2010 in the Med Sea (contribution to EuroArgo). They will surface according to
the predicted passage of A3 and they will send 1Koctet of data over 1 pass. A testing platform
has been developed to help define the transmission strategy. Good results have been obtained
in the lab.
We are currently investigating the feasibility of developing high-pressure profiling floats. We
should be able to conclude in 2010. Finally, we also investigate the feasibility of measuring
nitrates from PROVOR floats.
Deep NINJA
Tsurumi Seiki Co. Ltd. (TSK), in cooperation with JAMSTEC, is developing a new profiling float
for a depth greater than 2000 dbar: Deep NINJA. It has a new buoyancy engine, which is a
hybrid system of single-stroke piston engine and hydraulic pump engine. The prototype
hardware of Deep NINJA will be finished to be assembled probably in summer 2010 and the
field tests will be done within a year. While the buoyancy engine of the prototype of Deep
NINJA was originally designed for the maximum operation depth of 3000-dbar, its laboratory
test indicated that the engine functioned very well even at 3500 dbar, which is the safety limit of
the pressure tank. It is likely that the engine works at a greater pressure level. JAMSTEC
hopes that TSK improves it to be good for the depth of up to 4000 dbar.
SOLO-II
Dean Roemmich reported that there are now two SOLO-II prototype floats in the ocean
operating at accelerated cycling intervals, and the first production run of about 30 S-II floats is
planned for later this year. Attributes of the S-II include its small size (40 cm shorter than
SOLO), light weight (19 kg), low energy consumption for long life (> 200 cycles), 2000 m depth
capability anywhere in the world, Iridium communications, and no air bladder. While the basic S-
II is small, the instrument is scalable for additional batteries, sensors, and other features.
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