Comprehensive Ocean Atmosphere Data Set
Project DescriptionScientific Objectives:
Growing concerns with effects of climatic anomalies have brought the
realization that climate itself is dynamic and that observations from the
oceans require the same detailed study that has been devoted to observation
from stations on land for over a century.
These considerations formed the starting point for the construction of a
Comprehensive Ocean-Atmosphere Data Set (COADS). Development of COADS is a
continuing cooperative effort between the National Oceanic and Atmospheric
Administration (NOAA), its Environmental Research Laboratories, National
Climatic Data Center (NCDC), and Cooperative Institute for Research in
Environmental Sciences (CIRES), and the National Science Foundation's National
Center for Atmospheric Research (NCAR). Initiated in 1981, the COADS project
has used modern formats to minimize storage volume and other innovations in
data organization to provide for the first-time convenient and efficient
access to a unique record of ocean-atmosphere behavior, beginning in 1854 and
continuing into the future.
Global marine data observed during 1854-1979, primarily by
ships-of-opportunity, have been collected, edited, and summarized
statistically for each month of each year of the period, using 2 degree
latitude times 2 degree longitude boxes. Products now available in a first
release from this Comprehensive Ocean-Atmosphere Data Set include full
quality-controlled (trimmed) reports and summaries. Each of the 70 million
unique reports contains 28 elements of weather, position, etc., as well as
flags indicating which observations were statistically trimmed. The
summaries give 14 statistics, such as the median and mean, for each of eight
observed variables of air and sea surface temperatures, wind, pressure,
humidity, and cloudiness, plus 11 derived variables. Relatively noisy
(untrimmed) individual reports and summaries (giving 14 statistics for each of
the eight observed variables) are available for investigators who prefer their
own quality control. Two other report forms, inventories, and decade-month
summaries are among the other data products available. FORTRAN 77 software
available to help read 'packed binary' data products and processing details,
such as the method of identifying duplicate reports, are also described.
COADS products currently available from NCAR or NCDC are listed in the
following table. Product numbers correspond to Release 1 (gaps in numbering
refer to earlier versions of available products that are no longer supported).
Type of product is indicated by R (individual marine reports), M (2 degrees
year-month summaries), D (2 degrees decade-month summaries), or -- (other).
The number of tapes is based on a tape density of 6250 characters/inch.
Footnotes to commonly selected products give some additional details (minor
products may later be reviewed for retention). All tapes are available
through NCAR, except product number 19, which is available through NCDC.
PRODUCT TYPE No. of TAPES
1. Long Marine Reports (LMR)* R 48
2. Inventories (INV) -- 1
6. Decadal Summary Untrimmed Limits (DSUL) -- 1
8. Trimming Performance (TRP) -- 2
9. Decadal Summaries Trimmed (DST) D 2
10. Compressed Marine Reports (CMR)** R 18
12. Decadal Summaries Untrimmed (DSU) D 2
13. Monthly Summaries Untrimmed Timesort (MUS.T) M 9
14. Monthly Summaries Untrimmed Boxsort (MSU.B) M 9
15. Monthly Summaries Trimmed Timesort (MST.T) M 18
16. Monthly Summaries Trimmed Boxsort (MST.B) M 17
17. Monthly Summary Untrimmed Groups (MSUG) M 4
18. Monthly Summary Trimmed Groups (MSTG)*** M 10
19. NCDC Result (TD-1129)**** R 115
* The complete observational record stored in a variable-length format.
Sort is by 10 degree box, year, month, 1 degree box, day, hour, and deck.
Duplicate reports have either been eliminated or flagged. Coverage:
1800-1969 (56 'suspect' reports in 1800-1852 are included), 1970-79
separately; landlocked reports are flagged. Volume: 39.5 Gbit.
** A selection of 28 frequently used elements. Individual ship number or call
sign is omitted, as are wave and swell fields, etc. Variables outside
trimming limits were flagged. Sort is by 10 degree box, month, 2 degree box,
year, day, hour, longitude, latitude. Coverage: 1854-1969; 1970-79
separately; landlocked reports are flagged. Volume: 13.7 Gbit.
*** Five trimmed groups, each containing four variables, with eight statistics
included for each variable. Sort is by year, month, 2 degree box. Coverage:
1854-1979; landlocked data are deleted. Volume: 1.72 Gbit per group (4.5
million year-month-2 degree boxes). Two tapes per group file (thus 4
untrimmed and 10 trimmed tapes total).
**** The full observational record (except for some near-duplicate reports) in
an ASCII-Character TD-1129 format. Sort is by Marsden Square (MSQ), year,
month, 1 degree MSQ, day, hour, deck (or for 1970-79: MSQ, 1 degree MSQ, year,
month, day, hour, deck). Coverage: 1800-1969; 1970-79 separately; landlocked
reports are flagged. Volume: 84.6 Gbit.
National Center for Atmospheric Research
Data Support Section
P.O. Box 3000
Boulder, CO 80307
NCAR Home Page: http://www.ucar.edu/
National Climatic Data Center
151 Patton Avenue, Room 120
Asheville, NC 28801-5001
NCDC Home Page: http://www.ncdc.noaa.gov/
FTP: ftp hurricane.ncdc.noaa.gov
Woodruff, S.D., R.J. Slutz, R.L. Jenne, and P.M. Steurer: Bulletin of the
American Meteorological Society, Vol. 68, No. 10, October 1987, USA.
Slutz, R.J., S.J. Lubker, J.D. Hiscox, S.D. Woodruff, R.L. Jenne, D.H.
Joseph, P.M. Steurer, and J.D. Elms, 1985: Comprehensive Ocean-Atmosphere Data
Set; Release 1. NOAA Environmental Research Laboratories, Climate Research
Program, Boulder, Colo., 268 pp. (NTIS PB86-105723).