Nong et al. 
Arge 
All Deployments 
Launch location of all profiling floats deployed within the Argo program, by telecommunication type. 
Argo Data 1999-2019 
January 2020 
ARGOS (9996) =» IRIDIUM (5630) 
£ 
fen 
Generated by www.jcommops.org, 20/01/2020 
FIGURE 3 | Argo’s geographical coverage by telecommunication type. This map shows the launch location of all floats deployed within the Argo Program, as of 
January 2020. The red and blue dots denote floats that used Iridium and ARGOS telecsommunications, respectively. (Source: JCOMMOPSI]. 
time spent on the sea surface to < 20min for each cycle. 
Two-way communication via Iridium makes it possible to send 
instructions to the float for troubleshooting or for changing 
the float's mission (Roemmich et al., 2004). As a result of this 
transition from unidirectional to faster bidirectional satellite 
communication, there is now a large variety of float sampling 
missions and an even larger volume of float data. In 2014, 
Argo undertook a major revision of its data format in order 
to accommodate the increase in float data complexity as a 
result of Iridium telemetry and other auxiliarv sensars, including 
biogeochemical sensors. 
THE ARGO DATA SYSTEM AND ITS 
EXTENSION 
Components of the Argo Data System 
The initial design of the Argo data system took place in 2001 
at the 1st Argo Data Management meeting at Ifremer in Brest, 
France. The main components of the initial system have generally 
continued to function well 20 years later (Figure 4). The Argo 
data system was a descendent of the WOCE Upper Ocean 
Thermal (UOT) Data Centers. Shortcomings of the WOCE UOT 
rontiers in Marine Science | www.frontiersin.orı 
dataset, especially the lack of metadata, limited its application 
and were recognized and addressed in the design of the Argo 
data system. The data system was designed to serve the twin 
requirements of 
e operational users, who require access to Argo data within 24h 
of data telemetry, with obviously bad data flagged; and 
the research community, which requires high-quality data for 
scientific process studies and for climate monitoring. 
Implementing an open data policy at all levels of processing 
has made the Argo data system a pioneer in scientific ocean 
data delivery. Data are publicly and freely available via two 
Global Data Assembly Centers (GDACSs): the Coriolis Data 
Center in France and the US Navy’s Fleet Numerical Meteorology 
and Oceanography Center (FNMOC). Data are available in a 
common netCDF format and can be downloaded by File Transfer 
Protocol (FTP) or via a World Wide Web (WWW) interface. 
The two Argo GDACSs receive data that have been processed 
by 11 national Data Assembly Centers (DACs). Each float is 
allocated to a specific DAC. Functions of a DAC, as described 
below, may be centralized at a single institution or spread across 
several as appropriate. Data holdings at the two Argo GDACs are 
Qanteambear 2020 1 Valııme 7 | Article 701