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IABP Drifting Buoy Pressure, Temperature, Position, and Interpolated Ice Velocity

Summary

The International Arctic Buoy Programme (IABP) maintains a network of drifting buoys to provide meteorological and oceanographic data for real-time operational requirements and research purposes including support to the World Climate Research Programme (WCRP) and the World Weather Watch (WWW) Programme. An average of 25 buoys are in service at any time. The IABP drifting buoy data products described here are 12-hour interpolated pressure, temperature, position, and ice velocity grids available by year from 1979 through the present.

Drifting buoys measure atmospheric pressure, air temperature, and other geophysical quantities. These data are processed at the University of Washington's Polar Science Center, and are interpolated to produce gridded fields. Data are usually updated by May of each year, and are available online from the Polar Science Center. NSIDC catalogs the data set and provides this documentation with links to the Polar Science Center's IABP site in order to publicize and facilitate access to the data.

Several related data sets are available from the Polar Science Center's IABP site, including a CD-ROM containing IABP data and derived products from 1979 through 1999, an ocean buoy data set with temperature and salinity from drifting buoys from 1985 through 1994, GIF files graphically depicting gridded products, and a surface air temperature (SAT) data set (the IABP/POLES SAT data set) that combines data from buoys, manned drifting stations, and meteorological land stations.

Citing These Data

Rigor, I. 2002. IABP drifting buoy, pressure, temperature, position, and interpolated ice velocity. Compiled by the Polar Science Center, Applied Physics Laboratory, University of Washington, Seattle, in association with NSIDC. Boulder, CO: National Snow and Ice Data Center. http://dx.doi.org/10.7265/N53X84K7

The following example shows how to cite the use of this data set in a publication. For more information, see our Use and Copyright Web page.

Overview Table

Category Description
Data format Data are in space delimited ASCII text format and are available on a 2° x 10° grid and in EASE-Grid format. Data are downloadable in gunzip, ".gz", format.
Spatial coverage and resolution Data cover the northern latitudes of 70oN to 90oN, encompassing 360° of longitude.
Temporal coverage and resolution Data were reported every 12 hours beginning in 1979.
Tools for accessing data Data can be read with FORTRAN statements provided by International Arctic Buoy Programme (IABP).
File naming convention File names include the directory of which they are grouped under, AB, C, or D, and the year the data were recorded.
File size Data file sizes range from 45 KB to 3.4 MB compressed.
Parameters Atmospheric pressure, temperature, buoy position, and ice velocity were measured by AIBP.
Metadata access View metadata
Data access Data are available through the International Arctic Buoy Programme (IABP) at the University of Washington. Data are provided on a CD-ROM or via FTP.

Table of Contents

1. Contacts
2. Overview
3. Detailed Data Description
4. Data Acquisition and Processing
5. Data Access and Related Collections
6. References and Related Publications
7. Acknowledgements
8. Document Information

1. Contacts

Investigator

Ignatius Rigor
Polar Science Center
Applied Physics Laboratory
University of Washington
1013 N.E. 40th Street
Seattle, WA 98105 U.S.A.

Technical Contact

NSIDC User Services
National Snow and Ice Data Center
CIRES, 449 UCB
University of Colorado
Boulder, CO 80309-0449  USA
phone: +1 303.492.6199
fax: +1 303.492.2468
form: Contact NSIDC User Services
e-mail: nsidc@nsidc.org

2. Overview

Background

A network of automatic data buoys for monitoring synoptic-scale fields of pressure, temperature, and ice motion throughout the Arctic Basin was recommended by the U.S. National Academy of Sciences in 1974. Based on the Academy's recommendation, the Arctic Ocean Buoy Programme was established by the Polar Science Center, University of Washington, in 1978 to support the Global Weather Experiment. Operations began in early 1979 and the program continued through 1990 with funding from various agencies. In 1991, the Arctic Ocean Buoy Programme was superseded by the International Arctic Buoy Programme (IABP), although the basic objective remains the same: to establish and maintain a network of drifting buoys in the Arctic Ocean to collect data needed for real-time operations and meteorological and oceanographic research.

3. Detailed Data Description

Parameters and Coverage

The data record begins in 1979 and is ongoing. The processed data sets consist of atmospheric pressure, temperature, position, and ice velocity interpolated to a fixed grid of points in space and at 12-hour intervals (0000 UTM and 1200 UTM) daily. Data set AB contains pressure and temperature fields, data set C contains buoy positions, and data set D contains interpolated ice velocity fields computed from the buoy positions. The number of buoys deployed and the area they cover varies from year to year.

Data are interpolated to both a 2° longitude by 10° latitude grid, where latitude is 70 oN to 90 oN and longitude is 0o to 360o, and a rectangular EASE-Grid with 100 km resolution.

The format of the ASCII data files is described in annual data reports from 1995 to 2003 (ftp://iabp.apl.washington.edu/pub/IABP/Reports/). Included are also the data from each year complete with column headers and specified units.

Format

Data are in space delimited ASCII text format and are available on a 2° x 10° grid and in EASE-Grid format. Data are downloadable in gunzip, ".gz", format.

File and Directory Structure

Sample Data Record

The following sample data record is from the "84" data file found in the AB directory, which contains twelve-hourly pressure and temperature fields. These data are from 1984 and the columns correspond to the following:

  1. year
  2. month; 1 for January, 2 for February, etc.
  3. day
  4. hour in GMT (0 or 12)
  5. latitude in degrees north
  6. longitude in degrees east
  7. interpolated pressure in millibars
  8. interpolated temperature in degrees Celsius squared
  9. interpolation error variance in millibars squared
  10. interpolation error variance in degrees Celsius squared
  11. pressure derivative multiplied by 103 in the x direction in units of millibars per kilometer
  12. pressure derivative multiplied by 103 in the y direction in units of millibars per kilometer
  13. interpolated second derivatives (xx) of pressure multiplied by 106 in units of millibars per kilometer
  14. interpolated second derivatives (yy) of pressure multiplied by 106 in units of millibars per kilometer
  15. interpolated second derivatives (xy) of pressure multiplied by 106 in units of millibars per kilometer
84
1
1
0
70
0
956.5
-999.9
2.1
-9.9
-11
-15
52
4
38
84
1
1
0
70
10
954.9
-999.9
2.1
-9.9
-10
3
43
2
61
84
1
1
0
70
20
962.8
-999.9
2.1
-9.9
-9
27
37
6
41
84
1
1
0
70
30
975.5
-999.9
2.1
-9.9
-9
31
31
5
13
84
1
1
0
70
40
986.5
-999.9
2.1
-9.9
-10
20
20
-2
6
84
1
1
0
70
50
993.7
-999.9
2.1
-9.9
-6
11
15
5
5
84
1
1
0
70
60
998.2
-999.9
2.1
-9.9
-7
4
11
4
6
84
1
1
0
70
70
1002.6
-999.9
2.1
-9.9
-11
0
16
-1
4
84
1
1
0
70
80
1009.8
-999.9
2.1
-9.9
-20
4
5
-2
2
84
1
1
0
70
90
1018
-999.9
2.1
-9.9
-18
5
-9
-1
-2

The following sample data record is from the "C2003" data file found in the C directory, which contains buoy positions data. These data are from 2003 and the columns correspond to the following:

  1. year
  2. month; 1 for January, 2 for February, etc.
  3. day
  4. hour in GMT (0 or 12)
  5. buoy identification number
  6. latitude in degrees north
  7. longitude in degrees east
2003
1
1
0
1222
80.561
-136.472
2003
1
1
0
1907
76.644
170.393
2003
1
1
0
1908
74.4
-155.248
2003
1
1
0
5311
83.974
-118.374
2003
1
1
0
9120
84.012
26.058
2003
1
1
0
9834
79.918
177.131
2003
1
1
0
15524
72.943
-175.386
2003
1
1
0
19577
82.861
-162.599
2003
1
1
0
19578
80.304
-156.248
2003
1
1
0
20726
84.011
26.044

The following sample data record below is from the "D79" data file found in the D directory, which contains ice velocity estimates at a fixed grid of points. These data are from 1979 and the columns correspond to the following:

  1. year
  2. month; 1 for January, 2 for February, etc.
  3. day
  4. hour in GMT (0 or 12)
  5. latitude in degrees north
  6. longitude in degrees east
  7. interpolated ice velocity in the x direction in cm/s
  8. interpolated ice velocity in the y direction in cm/s
  9. variance of the interpolation error in velocity in dimensionless units
  10. interpolated velocity derivatives expressed in Cartesian coordinates (After multiplication by 10-7, the reported values have units of s-1.)
  11. interpolated velocity derivatives expressed in Cartesian coordinates (After multiplication by 10-7, the reported values have units of s-1.)
  12. interpolated velocity derivatives expressed in Cartesian coordinates (After multiplication by 10-7, the reported values have units of s-1.)
  13. interpolated velocity derivatives expressed in Cartesian coordinates (After multiplication by 10-7, the reported values have units of s-1.)
79
2
19
12
74
160
-1.1
-0.1
0.9
-0.1
0.31
-0.02
-0.02
79
2
19
12
74
180
-0.4
0.9
0.2
-0.42
-0.67
0.04
-0.29
79
2
19
12
74
200
2.3
3
0.1
-0.26
0.16
0.06
-0.23
79
2
19
12
74
220
0.7
2.1
0.1
0.07
0.11
-0.4
0.21
79
2
19
12
78
120
1.1
0
1
0.21
-0.44
0
0
79
2
19
12
78
140
1.1
0
1
0.32
-0.39
-0.01
-0.01
79
2
19
12
78
160
-0.1
0
0.8
0.88
0.02
0.03
-0.04
79
2
19
12
78
180
-0.6
0.8
0.2
0.7
-0.25
-0.03
-0.25
79
2
19
12
78
200
1.2
1.6
0.3
0.1
-0.18
-0.36
-0.14
79
2
19
12
78
220
1.3
0.6
0
-0.2
0.04
-0.38
0.04

Please refer to the International Arctic Buoy Programme and Arctic Buoy Data Web site for more information on the fields in each data record.

File Naming Convention

File names include the directory that they are grouped under, AB, C, or D, and the year the data were recorded.

File Size

Data file sizes range from 45 KB to 3.4 MB compressed.

WARNING: The AB data sets are 20 MB - 30 MB when uncompressed. Compressed, they are only about 4 MB, but if these data sets are retrieved through mosaic rather than through ftp, the user must make sure that there is enough disk space free in temporary and home directories. This will prevent a system crash from lack of available disk space.

Quality Assessment

Atmospheric pressure is typically measured using barometers with errors of < 1 mb.

Air temperature is measured using a variety of instruments. The thermistors typically have measurement errors of < 0.1oC, but where these instruments are installed on the buoys necessitates some care in interpreting the data. Prior to 1991, most measurements were taken from thermistors placed inside the hull of air dropped buoys, and were used primarily to calibrate the barometers. These buoys were sometimes covered with snow during winter, and were often warmed from insulation during summer. In 1992, the IABP began deploying buoys which measured true air temperatures from shielded thermistors at 2 meters height. For a detailed discussion of the temperature measurements from buoys, see Rigor et al. 2000.

Most buoys are positioned by the Argos systems on NOAA polar orbiting satellites. The Argos system results in positions with a measurement error of < 300 m. Global Position Systems have been installed on many of the newer buoys, and can be positioned with errors of < 100 m.

4. Data Acquisition

Please refer to the documentation provided by the Polar Science Center, Applied Physics Laboratory, at the University of Washington. Specific information on data acquisition and processing can be found in the documentation on the International Arctic Buoy Programme and Arctic Buoy Data Web site. In brief, buoy data are relayed via NOAA polar orbiting satellites to Service Argos in Toulouse, France and Largo, Maryland. These "raw" data are collected by the Polar Science Center, where they are quality controlled and interpolated to equal space and time intervals using objective analysis procedures (Rigor et al. 2000, Thorndike, 1986, Thorndike and Colony, 1982, and Thorndike and Colony, 1979). The data are also posted on the Global Telecommunications System.

5. Data Access and Related Collections

Data Access

Data are available online from the Polar Science Center, Applied Physics Laboratory, at the University of Washington. Raw data (data received from buoys prior to processing) are archived at the National Snow and Ice Data Center (NSIDC) and are available by special arrangement with the University of Washington Polar Science Center and NSIDC. Data are available through the International Arctic Buoy Programme (IABP) and are provided on a CD-ROM or via FTP.

Software and Tools

Data can be read with FORTRAN statements provided by the Polar Science Center, Applied Physics Laboratory, at the University of Washington. Visit the International Arctic Buoy Programme and Arctic Buoy Data Web site. Click on the "PSC Data Documentation" link under "Interpolated Data and Products."

6. References and Related Publications

For a complete list of references and related publications using IABP data, please visit the International Arctic Buoy Programme (IABP) Web site.

Brown, W. P. and E. G. Kerut. 1978. Air droppable RAMS (ADRAMS) buoys. AIDJEX Bulletin. 40:21-29.

Gandin, L. S. 1965. Objective analysis of meteorological fields. Gidrometeorologicheskoe Izdatel'stvo. Leningrad, translated from Russian. Israel program for scientific translations, Jerusalem. 242 pp.

Julian, P. R. and H. J. Thiebaux. 1975. On some properties of correlation functions used in optimum interpolation schemes. Monthly Weather Review. 103:605-616.

Martin, P. C. and M. Clarke. 1978. A test of barometric pressure and temperature measurements from ADRAMS buoys. AIDJEX Bulletin. 40:61-82.

Paros, J. M. 1976. Digital pressure transducers. Measurements and Data. 56, 10(2).

Rigor, I., R. Colony, and S. Martin. 2000. Variations in Surface Air Temperature Observations in the Arctic, 1979 - 1997. Journal of Climate. 13(5): 896-914.

Thorndike, A. S. and J. Y. Cheung. 1977. AIDJEX measurements of sea ice motions 11 April 1975 to 14 May 1976. AIDJEX Bulletin. 35:1-149.

Thorndike, A. S. and R. Colony. 1980. Arctic Ocean Buoy Program Data Report 19 January 1979 - 31 December 1979. Polar Science Center, University of Washington. Seattle, Washington. 131 pp.

Thorndike, A. S. 1981. Kinematics of Sea Ice. The Geophysics of Sea Ice. Edited by N. Untersteiner. New York: Plenum Press.

Thorndike, A. S., and R. Colony, 1982. Statistical properties of the atmospheric pressure field over the Arctic Ocean, Journal of the Atmospheric Sciences. 39, 2229-2238.

Thorndike, A. S, 1986. Kinematics of sea ice. The Geophysics of Sea Ice. Edited by N. Untersteiner. New York: Plenum Press. 489-569.

7. Acknowledgements

The International Arctic Buoy Programme (IABP) is funded and managed by its participants. Representing eight countries, participants include operational and research agencies, meteorological and oceanographic institutes, and nongovernmental organizations. Participant contributions include equipment, services, and program coordination, as well as funding.

The International Arctic Buoy Programme is partially funded through the U.S. Interagency Arctic Buoy Programme (USIABP). Refer to the International Arctic Buoy Programme (IABP) Web site for more information on program sponsorship.

8. Document Information

Document Creation Date

This document was created in 2002 by F. Fetterer.

Document Revision Date

This document was edited and reformatted in January 2006 by L Husted.

Document URL

http://nsidc.org/data/docs/noaa/g00791_iabp/index.html