Gonzâlez-Pola et al. 
ICES-WGOH Assessment on Ocean Climate 
Frontiers In Marine Science | www.frontlersln.org 
6 
March 2019 | Volume 6 | Article 103 
sampling by the Norwegian Ocean Weather Station “M” was 
discontinued with the removal of the last weather ship in 
2010 (Yelland et al., 2009). As a replacement, hydrographic 
observations from this location derive now from subsurface 
instrumentation in the framework of OceanSITES 8 plus research 
ships visits up to five-six times per year. Finally, surface 
temperature measurements collected via ship of opportunity at 
52°N along the southern North Sea were discontinued in 2002 
with the removal of the ferry line. However, the timeseries may 
now continue using observations from a nearby Smartbuoy (See 
Figure 77, p.81, in Gonzalez-Pola et al., 2018). 
Currently, only a portion of the IROC timeseries are 
systematically being incorporated into Global Operational 
Databases and hence contributing effectively to GOOS. This 
issue is a major concern of the WGOH, already highlighted 
in the previous white paper authored by the group (Holliday 
et al., 2010). One challenge is that most hydrography derived 
from national monitoring programs are only available in delayed 
mode, while current demands expect real-time availability. In 
addition, many repeat hydrography programs do not meet 
the GO-SHIP 9 sampling criteria and hence datasets are not 
incorporated through JCOMMOPS 10 . The lack of a home 
for classical hydrographic cruises has been highlighted as a 
weakness of the current JCOMMOPS structure. On the other 
hand, the ICES Data Center has long focused on hosting 
delayed mode CTD and discrete water bottle data from 
ICES areas, which are routinely incorporated into the US 
World Ocean Database and Atlas 11 and made available to the 
global community. 
As automated sampling develops, science programs are 
beginning to consider the relative benefits of more traditional 
in-situ sampling. Oceanographic cruises are becoming more 
multidisciplinary, with biogeochemistry often included as a 
mandatory component, while hydrography stands as a basic 
record. Further, in-situ hydrography remains essential for the 
groundtruthing of data from autonomous vehicles and profiling 
floats. Hence, while autonomous systems may supplement in-situ 
measurements made via ship or moored array in long-standing 
programs, we argue that these traditional observations will be 
required well into the future. Despite the delayed delivery, IROC 
timeseries offer significant added value to GOOS programs. 
In particular, (i) IROC observations sample the deep ocean 
in a variety of locations across the North Atlantic, filling a 
major gap in present day GOOS where deep observations (> 
2000 m) are limited to GO-SHIP sections (Deep Argo floats 
and deep gliders still have a long way to fully cover the gap) 
and (ii) IROC observations bridge a gap between the blue ocean 
and regional seas, shelves and oceanic boundaries, where most 
classical monitoring programs take place but the Argo network 
cannot access. 
8 www.oceansites.org 
9 The Global Ocean Ship-Based Hydrographic Investigations Program 
www.go-ship.org/DatReq.html 
10 WMO-IOC Joint Technical Commission for Oceanography and Marine 
Meteorology in-situ Observing Programmes Support Centre www.jcommops.org 
11 www.nodc.noaa.gov/ about/oceanclimate.html 
4. CONCLUSION AND OUTLOOK 
For decades, the ICES-WGOH has provided ICES and the 
oceanographic community with information on the condition 
of the North Atlantic Ocean by updating and reviewing 
results from standard long-standing hydrographic sections and 
stations. WGOH continues a long tradition of international 
collaboration, bringing together physical oceanographers with 
regional expertise and a rich collection of ocean data to 
contribute to this annual assessment. While global ocean 
observation has evolved in the past decade, greatly increasing 
in volume and complexity, the WGOH-IROC continues to be a 
key link between regional ocean monitoring and research, and 
actual policy advice. Looking toward the future, ICES-WGOH 
has much to offer the burgeoning GOOS community, including a 
history of observations in key areas of the ocean and experience 
in meeting the needs of fisheries scientists. However, further 
engagement with GOOS is essential. WGOH will continue 
to track key observational timeseries, stressing continuity 
and quality while working to incorporate these data into 
the GOOS system. 
DATA AVAILABILITY 
The datasets analyzed for the IROC discussed in this white paper 
can be downloaded at the IROC online web page https://ocean. 
ices.dk/iroc/ 
AUTHOR CONTRIBUTIONS 
CG-P conceived the white paper and coordinated the group. 
CG-P, PF, KL, and NH designed the paper structure and 
defined the key contents. CG-P took the lead in writing the 
manuscript and PF performed thorough draft reviews. RG 
analyzed the characteristics of the collection of timeseries 
and created a graphical representation of the outcome. 
All authors commented on the manuscript providing 
specific feedback. 
FUNDING 
The work carried out over the years by the WGOH under 
the auspices of ICES is supported by many monitoring 
programs across the North Atlantic and Arctic regions, 
either run by working group members hosting institutions or 
other institutions/consortia. WGOH work and meetings are 
possible through the economical commitment of ICES member 
countries. 
ACKNOWLEDGMENTS 
The authors wish to thank ICES for promoting international 
networking through expert groups, WGOH members hosting 
institutions for sponsoring their active participation in the 
Working Group and all institutions/projects/people behind the 
IROC timeseries collection.