International Comprehensive Ocean-Atmosphere Data Set (ICOADS)

Program Status

As the result of a US project starting in 1981, available global surface marine data from the late 17th century to date have been assembled, quality controlled, and made widely available to the international research community in products of the Comprehensive Ocean-Atmosphere Data Set (COADS). A new name, International COADS (ICOADS), was agreed in 2002 to recognize the multinational input to the blended observational database and other benefits gained from extensive international collaboration, while maintaining continuity of identity with COADS, which has been widely used and referenced.

The original COADS project, and the continuing US contribution toward the new international partnership on ICOADS, is the result of cooperation since 1981 between the National Oceanic and Atmospheric Administration (NOAA) and the National Science Foundation's National Center for Atmospheric Research (NCAR). The NOAA portion of ICOADS is partially funded by the NOAA Climate Program Office (CPO).

ICOADS data are made available in two primary forms:

  • Observations: Surface marine reports from ships, buoys, and other platform types. Each report contains individual observations of meteorological and oceanographic variables, such as sea surface and air temperatures, wind, pressure, humidity, and cloudiness.
  • Monthly summary statistics: Ten statistics (such as the mean and median) are calculated for each of 22 observed and derived variables, using 2° latitude x 2° longitude boxes back to 1800 (and 1°x1° boxes since 1960).

Release 3.1 observations are available for 1662-2014 (456 million individual marine reports), 2° monthly summaries for 1800-2014, and 1° summaries for 1960-2014. In addition, preliminary observations and monthly summaries are available from 2015 forward (updated monthly, and lagging real-time by 2-6 weeks). These data and summary products are drawn from two separate archives:

  1. The most complete and highly processed observations are from the delayed-mode (ICOADS.DM) archive, covering 1662-2014 (note that data from 1662 through the early 1800s are extremely sparse, based on scattered ship voyages; this webpage provides extensive additional information on Release 3.0 data characteristics;). This version marks the first time multi-line linked reports (Main plus Subsidiary) in IMMA1 data format have been used. The Subsidiary records are linked to the Main records through replication of the unique identification number and expand the IMMA1 capability to hold ICOADS value-added data (Ivad) and reanalysis feedback quality control (Rean-qc) information.
  2. Less fully processed observations, limited to Global Telecommunications System (GTS) data, are from the real-time (ICOADS.RT) archive. These data represent an improved near-real-time (NRT) product blending observations from GTS BUFR and TAC formats.

The observations and monthly summary products currently offered to users are all from ICOADS.DM through the end of 2014. That official Release 3.1 period is followed by preliminary observations and monthly summaries based on the ICOADS.RT archive.

Update plans are as follows:

  1. As resources permit, ICOADS.DM will be enriched with newly available or improved data, and periodically be used to replace the preliminary ICOADS.RT data.
  2. Release numbering will refer to the following for R3.0 and are subject to change when incremental updates are performed:
    • R3.1.0 — Official ICOADS.DM 1662-2014
    • R3.0.2 — Preliminary ICOADS.RT 2015 to most current complete month.
    Any new incremental updates to R3.0 will be announced on the ICOADS website.
  3. The improved preliminary IMMA observations and monthly summaries extending past the official end date of Release 3.1 represent an further step towards updating ICOADS in near-real-time.

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Updated: Feb 25, 2022 12:57:01 UTC