1. Deployments of Deep Argo pilot arrays Indian Ocean and Southern Ocean JAMSTEC Toshio Suga & JAMSTEC collegues Research and Development Center for Global Change, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Japan US Argo/NZ Argo Input from Dean Roemmich and Nathalie Zilberman

2. Observation status Latest status (update monthly) : http://www.jamstec.go.jp/ARGO/deepninja/ 2 DeepNINJAs start monitoring for deep Indian Ocean.

3. Deep NINJA: The first practical float measurable in the deeper ocean than 2000m Specification of Deep NINJA Max. profile depth: 4000 dbar Available from the tropics to the high-latitudes with seasonal ice About 90% of the ocean’s volume is measurable Pressure hull: Aluminum alloy Sensor: SBE 41CP Enough capacity for additional sensors Communication: Iridium SBD, two-way Position fixing: GPS Est. lifetime: (more than) 1 year (by Lithium battery) Functions:Avoidance of surface sea ice Avoidance of groundings 210 cm 25 cm 50 kg

4. Identify the seasonality of deep ocean for Indian basin =>helpful to detect climate signals, for instance, when using repeat hydrography data. =>effective constraint for deep ocean state estimate by ESTOC Scientific Target Examine the ability to detect the long-term (inter annual to pentadal) climate signal =>Indian Ocean shows bottom- water cooling, which is different from other major basins except of North Atlantic. 4000-5000m water temp change 5000m-bottom water temp change

5. Indian Ocean Pilot Array 投入風景 Recent profiles of T/S We deployed 2 Deep NINJAs around end of January. Now, they have provided four profiles until now. They are in operation with the previouly deployed SO Deep NINJAs. フロートを分解すること なく、センサー部に海水 を通して実施する簡易検 定機器 水温 塩分 水温 塩分

6. 2016 plan Hopefully, one more deep NINJA for Indian array…At present, we can not find a suitable cruise for a deployment. [Southern Ocean] 2 deep NINJAs for the CSIRO inter-comparison Project. [North Pacific] 1 Do- deep-apex for an impact experiment by using a JAMSTEC state estimation system ESTOC.

7. US Argo/NZ Argo: R/V Kaharoa, Deep Argo 2016-17 R/V Kaharoa cruise in October-December 2016 Red circles: Deep Argo floats