Deep NINJA

It can observe the deep ocean up to 4,000 m depth automatically and globally.

It is the first deep float developed by JAMSTEC and Tsurumi-Seiki Co. Ltd.


Project Abstract

Importance of deep ocean observations by deep floats and Deep NINJA

The importance of deep ocean observations has been gradually recogni zed to understand oceanic effects on anthropogenic climate change accurately, especially the oceanic heat content and th e sea level rise. To make such observations, deep floats are among the most suitable devices to observe deep ocean at re asonable cost and a monitoring network with numerous such deep floats, "Deep Argo", is urgently needed. Until recently, there were no such floats available for waters below 2,000 m in depth, but now a number of international universities, i nstitutes, and float makers are developing such deep floats.The Japan Agency for Marine-Earth Science and Technology (JA MSTEC) and Tsurumi-Seiki Co., Ltd. (TSK) began work on the development of a deep float in 2010, and ultimately succeeded with "Deep NINJA" in April 2013. Deep NINJA is capable of observing the ocean at depths up to 4,000 m global ly, except for those seas that are covered by ice throughout the year. Figure 2 shows a schematic view of a Deep NINJA f loat in operation in the ocean alongside a normal (Argo) float.

Deep ocean observations by Deep NINJA floats operated by JAMSTEC

To date, JAMSTEC has deployed 14 Deep NINJA floats (including two pr ototypes) in collaboration with TSK, primarily in the Southern Ocean. As of July 25, 2014, these floats have/had continu ed to operate well and have observed more than 190 oceanic profiles. Notably, one Deep NINJA float (S/N 6) deployed off the Adelie Coast of Antarctica measured deep profiles under sea ice throughout an Antarctic winter and continued to obse rve seasonal changes of the deep/bottom waters for more than one year.This website introduces the Deep NINJA float itsel f and provides listings of the Deep NINJA observations. These include the d ates and locations of float deployments and observation parameters such as observation cycle and profile depth. Addition ally, there are several figures showing observation results, such as float movement trajectories, temporal changes of te mperature and salinity profiles as measured by the floats.


Figure 1:Deep NINJA

Specifications of Deep NINJA


  • Maximum operating depth:4,000dbar(~4,000m)
  • Size:210 cm long and 50 kg in air
  • Sensor:SBE41CP for deep float (Sea-Bird Electronics, US)
  • Transmission:Iridium, Short Burst Data Service (two-way)
  • Positioning:Global Positioning System
  • Service life:More than one year, powered by lithium batteries

Figure 2:Schematic overview of a Deep NINJA observation float in operation alongside an Argo float.

Figure 3:Deployment of the first DeepNINJA from R/V Wakataka-maru in August 2012.

Figure 4:Deployment of Deep NINJA offthe Adelie Coast, Antarctica, from R/V Mirai in December 2012.


Data

Release of scientifically quality-controlled data of Deep NINJA observations

Observations using Deep NINJA floats are carried out as part of theJapan Argo Project. Herein, we provide a quality-controlled dataset of Deep NINJA observations for convenient use on scientific/educational purposes. The quality-control effort led by JAMSTEC was based primarily on comparisons with highly accurate shipboard conductivity-temperature-depth (CTD) observations conducted nearby float observations. For permissionto access this data, please contact us after reviewing and confirming your acceptance of the Terms and Conditions provided below.
All raw and officially quality-controlled data of the Deep NINJA observations are expected to be made available to the public via the Argo Global Data Assembly Centers (GDACs) in the near future, probably under the same framework as International Argo. Note that the (raw) measurements of Deep NINJA still include some issues that need to be resolved and examined on their quality as follows:

  1. The Deep NINJA CTD sensor, which is the current standard model for deep floats, wasdeveloped originally for "Argo floats," which operate in water depths shallower than 2,000 m. Its performance under high pressure in deep ocean waters has not been examined sufficiently.
  2. Temperature and salinity measurements of the CTD sensor have a bias that depends on pressure. JAMSTEC has found that the salinity measurements of Deep NINJA tend to be fresher at higher pressure.

Terms and Conditions

The copyrights for the quality-controlled data of Deep NINJA floats belong exclusively to JAMSTEC.

contact: 

 


Inventory Data

Serial No. Date for deployment Area for deployment Position for deployment Deploy ship name / cruise Cycle [day] Parking depth [dbar] Profile depth(s) [dbar] Number of profiles (that of deep profiles) Status
1* 2012/8/29 Subarctic, North Pacific 40° 40.00 N, 144°46.18 E Wakataka-maru WK1208 5 1000 4000 1 (1) Dead (failure at communication unit?)
2* 2012/8/29 Subarctic, North Pacific 40° 40.00 N, 144°46.18 E Wakataka-maru WK1208 10 1000 2000/4000 21 (16) Dead (Energy consumption?)
3 2012/12/19 Off the Adelie Coast, Antarctica 60° 00.62 S, 139°56.12 E Mirai MR12-05 15 2000 4000 15 (9) Dead (unknown)
4 2012/12/5 South of NZ, Southern Ocean 56° 59.87 S, 173°59.31 E Mirai MR12-05 15 2000 2000/4000 50 (25) Dead (energy consumption?)
5 2012/12/17 Off the Adelie Coast, Antarctica 62° 00.38 S, 137°00.42 E Mirai MR12-05 30 2000 4000 14 (10) Dead (accident at sea ice?)
6 2012/12/16 Off the Adelie Coast, Antarctica 62° 45.73 S, 143°36.05 E Mirai MR12-05 30 2000 4000 27 (23) Dead (accident at sea ice?)
7 2013/7/17 Subtropcal, North Pacific 30° 03.91 N, 144°58.09 E Mirai MR13-04 10 3000 4000 33 (33) Dead (energy consumption?)
8 2014/3/6 Off the Adelie Coast, Antarctica 63°40.55 S 148°35.65 E Shirase JARE55 20 3000 4000 3 (3) Dead (accident at sea ice?)
9 2014/3/7 Off the Adelie Coast, Antarctica 59° 14.34 S, 150°08.85 E Shirase JARE55 20 2500 4000 23 (23) Dead (unknown)
10 2014/1/23 Off the Budd Coast, Antarctica 62° 55.0659 S, 109°59.8474 E Umitaka-maru UM041 20 2000 4000 0 (0) Dead (unknown)
11 2014/1/19 Off the Budd Coast, Antarctica 60° 03.4988 S, 109°53.3204 E Umitaka-maru UM041 20 3500 4000 10 (10) Dead (accident at sea ice?)
12 2014/1/22 Off the Budd Coast, Antarctica 62° 00.4176 S, 110°00.1893 E Umitaka-maru UM041 20 3500 4000 5 (5) Dead (accident at sea ice?)
13 2014/1/27 Off the Budd Coast, Antarctica 64° 15.8987 S, 107°41.9985 E Umitaka-maru UM041 20 3000 4000 24 (24) Dead (accident at sea ice?)
14 2014/1/24 Off the Budd Coast, Antarctica 64° 05.3637 S, 109°51.0107 E Umitaka-maru UM041 20 3000 4000 40 (40) Dead (energy consumption?)
15 2014/12/6 Off the Budd Coast, Antarctica 59° 59.96 S, 109°51.92 E Shirase JARE56 20 3500 4000 44 (44) Dead (energy consumption?)
16 2016/1/31 Western Indian Ocean 29°59.98S 52°32.01E Hakuho-maru KH-16-1 30 2000 4000 18 (18) Dead (unknown)
17 2016/2/2 Western Indian Ocean 40°41.49S 45°54.43E Hakuho-maru KH-16-1 30 2000 4000 76 (76) Dead (Energy consumption?)
18 2016/3/2 Subtropical, North Pacific 29°56.31N 147°27.26E Ryofu-maru 1602 30 2000 4000 18 (18) Dead (unknown)
20 2017/2/19 South Pacific, Southern Ocean 60°58.01S 125°59.98E Mirai MR16-09 10 2000 4000 5 (5) Dead (unknown)
21 2017/7/10 North Pacific 47°0.108N 154°59.406W Hakuhomaru KH-17-3 10 2000 4000 3 (3) Dead (unknown)
22 2018/2/3 Off the Adelie Coast, Antarctica 65°0.036S 145°30.108E INVESTIGATOR 20 2000 4000 78 (78) Active
23 2017/7/23 North Pacific 47°0.012N 160°1.332E Mirai MR17-04 10 2000 4000 9 (9) Dead (unknown)
24 2018/1/29 Off the Adelie Coast, Antarctica 63°21.312S 139°49.830E INVESTIGATOR 20 1000 4000 17 (17) Dead (unknown)
25 2018/2/5 Off the Adelie Coast, Antarctica 63°30.156S 149°59.838E INVESTIGATOR 20 2000 4000 15 (15) Dead (unknown)
26 2017/12/1 North Indian Ocean 5°3.582S 95°2.712E Mirai MR17-08 10 2000 4000 11 (11) Dead (unknown)
27 2018/12/30 Eastern Pacific Ocean 9°57.852S 130°0.420E Mirai MR18-06 30 2000 4000 29 (29) Dead (unknown)
29 2020/01/27 Off the Adelie Coast, Antarctica 63°0.048S 115°0.192E Umitakamaru UM059 20 2000 4000 53 (53) Active
30 2019/01/10 Off the Adelie Coast, Antarctica 60°59.976S 110°0.018E Umitakamaru UM056 30 2000 4000 14 (14) Dead (unknown)
31 2018/12/29 Off the Adelie Coast, Antarctica 62°59.400S 112°14.898E Kaiyomaru 201801 10 2000 4000 0 (0) Dead (unknown)
*:Prototype As of Jul. 27, 2021

 

Figure 5: The deployment map of Deep NINJAs

©Japan Agency for Marine-Earth Science and Technology (JAMSTEC) 2017