Biogeochemical Floats in Argo

Stephen C. Riser University of Washington

Argo Steering Team Meeting

Halifax, NS 18 March 2014

BGC floats deployed in Argo

Estimated costs of BGC floats and basic sensors

a

b

c

aAanderaa 4330; SBE 63 is now being tested bMBARI ISUS; Satlantic ISUS/SUNA is more (×2?) cMBARI version; commercial version (SBE) in progress

Dissolved O2 calibration and adjustment is an active area of discussion; see results from the recent SCOR Working Group 142 Meeting

Example of a BGC data from float in the southern Indian Ocean

http://flux.ocean.washington.edu/argo

[500 T/S samples, 100 BGC samples]

Iridium antenna

Optode O2 sensor

SeaBird 41-CP CTD

ISUS (embedded in

CTD outflow)

FLBB sensor

The general configuration of BGC floats produced at UW

The Deep-Durafet pH sensor developed by MBARI for use on profiling floats

pH sensor and reference electrode (in the CTD outflow)

Profiles of pH measured near the HOT site from UW floats equipped with a deep Durafet sensor (from K. Johnson)

Energy Considerations for BGC Floats Number of Lithium Battery Packs: 4 Energy per Pack: 1300 KJ Total Energy Available: 5200 KJ Energy per Profile: 19.82 KJ Estimated Number of Profiles Possible: 262

System Energy Required (KJ) Per Cent of Total

Buoyancy pump 6.42 32.4

ISUS/NO3 3.62 18.3

SBE 41CP 3.04 15.3

Iridium-GPS 2.50 12.6

APF9i 1.99 10.0

Durafet/pH 1.28 6.5

FLBB 0.16 1.3

Optode/O2 0.10 0.5

Self-discharge 0.70 3.5

TOTAL 19.82 100

Apex T/S

Apex BGC

Navis BGCI

3 float types

Satlantic SUNA configured on a SBE Navis BGCI float

16 BGC floats to be deployed along P16 (March-May 2014)

Planned/proposed deployments as part of SOCOM (200 floats over 6 years). Basic funding from NSF, with half the floats provided by US Argo.