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when this parameter One major necessary was altered between improvement is to adthe ninth to 10th just the parameters in cycle. The foat will order to gain control of spend several days the foat mechanics effwaiting for the next ciently, which will save observation by driftenergy and extend the ing at a preset depth duration of foat operain the subsurface, as tion in the sea. demonstrated in the In the austral sumthird cycle. While mer of 2012 and 2013, drifting, the foat will four Deep NINJA foats be returned to its prewill be deployed in set depth if carried the Indian sector of the more than 25 meters Southern Ocean by the The vertical movement of a Deep NINJA foat during the deep feld test. away, as shown durRV Mirai, operated by ing the seventh and JAMSTEC. The foats the ninth cycle. are expected to observe the waters near the seafoor off the The drifting depth is changeable by the user. During the Ad��li Coast of Antarctica. These deep foats may make the test, this parameter was changed twice, from 1,000 meters frst attempt of such direct observations of deep and bottom to 3,500 meters and then to 4,000 meters. The quick aswaters and their vertical structure in the Southern Ocean cent (i.e., observation without subsurface drifting), which for longer than a year. Profles obtained by the Deep NINJA was completed during the second cycle, was controlled by feet are expected to provide new and useful discoveries. an operator. A command via e-mail can instruct the foat Tsurumi Seiki Co. Ltd. will likely begin mass production to measure a profle from the deep profle-depth (second, of the Deep NINJA in 2013. fourth and ffth cycles) or the middle profle-depth (17th cycle). This function enables the foat to observe oceanic Acknowledgments events that occur after its deployment. The authors would like to acknowledge and thank the The period of the observation cycle is also changeable. other members who took part in the development of Deep The initial setting for the period was 120 hours, and then NINJA: K. Amaike, T. Ino, K. Asakawa, T. Suga, T. Kawano was changed to 72 hours at the ffth cycle. At the end of the and T. Hyakudome. They also express their gratefulness to feld test, the foat was changed to the standard observation the captain and crew of the Wakataka-maru, and Dr. Ito and mode (one 4,000-meter observation for every two 2,000-methe other researchers on board for their help and cooperater observations with 10-day cycles) by commands inputted tion in the deployment of foats during the deep-sea feld by an operator. As of November, it has performed very well. test. n The other foat was, unfortunately, lost just after data Taiyo Kobayashi is a senior research scientist in physical oceanography at JAMtransmission of the frst 4,000-meter profle on its second STEC, with expertise in foat observations. He has worked with the Argo proday of deployment due to trouble with its communication gram for more than 10 years, since its beginning. He is also involved in foat module. The problem likely stemmed from a miscommunidevelopment. cation between the foat and Iridium satellites since it took Kazuhiro Watanabe is a senior mechanical engineer at Tsurumi Seiki Co. Ltd. three-and-a-half hours to transmit all e-mails with the obHe has worked on the development of oceanographic instruments for almost served data, which is normally done within one hour. 40 years and has been engaged in the development of Deep NINJA since the beginning of its feasibility studies. Future Plans The deep-sea feld test distinguishes several points that need improvement to enhance the quality of Deep NINJA. 44 st / FEBRUARY 2013 Michihiko Tachikawa is the president of Tsurumi Seiki Co. Ltd., a manufacturer of oceanographic instruments and systems. www.sea-technology.com