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A Q&A with ICOADS: Historical Marine Data for Climate Research Severely Reduced


By Pennell Paugh and Joan O’Brien

IEDRO recently interviewed Scott D. Woodruff, director of NOAA’s International Comprehensive Ocean-Atmosphere Data Set (ICOADS) program.

Q: First, can you explain what the ICOADS program does?

A: We collect and store in situ (data collected from the ground) surface marine meteorological data. Data presently extending back to the late 1600s have mostly been extracted from ships’ logbooks. Starting around 1970, we began accumulating data taken from moored and drifting buoys and other automated platform types.

Q: What is your source of old ships’ logs for early periods?

A: Well, many maritime countries have an archive repository. The UK has a particularly large collection. We also have tapped European as well as other international archives. Many of these historical records remain untapped or underutilized, and could fill important temporal and spatial gaps in the current ICOADS record.

Q: Getting all that information translated so it’s usable in modern databases must be a challenge. How have you accomplished this?

A: As an important part of the solution, NOAA, under its Climate Database Modernization Program (CDMP), until recently operated about 90 digitization projects—many supporting activities independent from ICOADS. Unfortunately, in March of last year the entire CDMP program was disbanded due to budget cutbacks.

Q: How are you digitizing the data now?

A: If not for assistance from international initiatives by Atmospheric Circulation Reconstructions over the Earth (ACRE), marine data archeology and digitization probably would have largely stopped. For example the Old Weather collaboration, found at, provides a “Citizen Science”-based effort. Using a website, nearly 90,000 volunteers transcribe data from ships’ logs.

Q: Tell us about recent changes made to the ICOADS program.

A: ICOADS operated for decades in the US as a partnership between NOAA, its Earth System Research Laboratory (ESRL); the National Climatic Data Center (NCDC); and the National Center for Atmospheric Research (NCAR), along with growing international contributions. However, in December 2011 ESRL directors determined that it was no longer feasible for its Physical Science Division (PSD) to continue financing ICOADS. While ICOADS will continue archiving real-time marine surface observations, the retrospective rescue and blending of historical records to improve ICOADS has been suspended.

Q: Are some solutions forthcoming?

A: Data retrieval from ICOADS from the remaining project partners, NCDC and NCAR, is still operational. Moreover, in view of the program’s critical scientific importance, NCDC and NCAR are committed to ensure the long-term viability of ICOADS, and have begun shifting some key responsibilities from ESRL. NCDC is now maintaining and helping to enhance the near-real time data update with modern equipment.

Q: One of our scientists takes the digitized data from a country in which we have rescued their historical data and shows government officials and interested groups, such as farmers, how to use simple tools to analyze trends. He uses several easy-to-use portals. Do you perhaps have a similar portal?

A: Yes, our central web-portal for all ICOADS data and documentation services is

Q: What are some of the repercussions for the reduced pace of digitization and the suspended merger of historical data into ICOADS?

A: ICOADS’ observations, together with associated metadata and basic gridded products, have served a wide range of climate and regional research. ICOADS has provided the critical data underpinning global analyses of temperature, atmospheric reanalyses, and national and international scientific assessments of climate, including by the Intergovernmental Panel on Climate Change (IPCC).

Small scale historical data recovery projects, usually connected to specific projects, were encouraged to submit their data to ICOADS for the benefit of the wider scientific community. If ICOADS remains almost static for very long the wider community will lose that added value and the funding of new data recovery projects will be put at risk.

In an attempt to fill the gap created by the suspension of historical data taken in by ICOADS, there is a danger that as data recovery continues we will end up with many fragmented data sets, many not known to the wider community. We will then lose a ‘one-stop shop’ for all data. As a direct consequence, fragmented data sets could eventually be lost as the storage technology used to support them becomes outdated. With ICOADS, there was a long-term stable platform.

ICOADSinterviewLargeFigure, right, illustrates the recent platform type mixture of ICOADS: Annual distribution (1937-2007) of major platform types in Release 2.5 shown as millions of reports per year. For clarity the vertical scale is truncated at 9M; years 2005-07 have 13M, 15M, and 16M total reports (not visible) in Release 2.5, respectively. The red line curve shows the Release 2.4 annual counts. Ships (mainly VOS plus some R/Vs), buoys, and oceanographic are self explanatory, Ocean (permanent) Station Vessel = OSV, Coastal-Marine Automated Network = C-MAN, ocean drilling rigs/platforms and other small entities = other, and unidentified platform types = missing. (Ship photo courtesy Figure adapted from: Woodruff, S.D., H.F. Diaz, E.C. Kent, R.W. Reynolds, and S.J. Worley, 2008: The evolving SST record from ICOADS. In Climate Variability and Extremes during the Past 100 Years (S. Brönnimann, J. Luterbacher, T. Ewen, H.F. Diaz, R.S. Stolarski, and U. Neu, Eds.), Advances in Global Change Research, Vol. 33, Springer, 65-83.


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