Historical Arctic and Antarctic Surface Observational Data

Summary

This product consists of meteorological data from 105 Arctic weather stations and 137 Antarctic stations, extracted from the National Climatic Data Center's (NCDC) Integrated Surface Hourly (ISH) database. Variables include wind direction, wind speed, visibility, air temperature, dew point temperature, and sea level pressure. Temporal coverage varies by station, with the earliest record in 1913 and the latest in 2002. Data are in tab-delimited ASCII text format, with one file per station and year. Graphs of meteorological variables throughout the time series accompany the ASCII data. Data are available via FTP.

Citing These Data

We kindly request that you cite the use of this data set in a publication using the following citation example. For more information, see our Use and Copyright Web page.

Stroeve, J., and C. Shuman. 2003. Historical arctic and antarctic surface observational data. Boulder, CO: National Snow and Ice Data Center. Digital media.

Overview Table

Category Description
Data format Data are in tab-delimited ASCII text format.
Spatial coverage and resolution Data are from 105 automatic weather stations in Iceland and Greenland, and 137 stations in Antarctica.
Temporal coverage and resolution Temporal coverage varies by station. The earliest record is in 1913, and the latest is in 2002. Data from automated weather stations were recorded on an hourly basis; temporal resolution from other sources varies from station to station.
Data range See the Column Descriptions table in this document.
File naming convention An example file naming convention is "040010_2001.dat," where "040010" is the station ID and "2001" is the four-digit year.
File size Data files range from 1 KB to 1.5 MB.
Parameter(s) Variables include wind direction, wind speed, visibility, air temperature, dew point temperature, and sea level pressure.
Procedures for obtaining data Data are available via FTP.

Table of Contents

1. Contacts and Acknowledgments
2. Detailed Data Description
3. Data Access and Tools
4. Data Acquisition and Processing
5. References and Related Publications
6. Document Information

1. Contacts and Acknowledgments

Investigator(s) Name and Title

Julienne Stroeve
National Snow and Ice Data Center
CIRES, 449 UCB, University of Colorado
Boulder, CO  80309-0449

Christopher Shuman
NASA Goddard Space Flight Center
Code 971, Building 33, Room A210
Greenbelt, MD  20771

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. Detailed Data Description

Format

Data are in tab-delimited ASCII text format. Each file contanis one year of data and begins with a two-line header that provides the fixed weather station ID, latitude and longitude of the station, geophysical report type, elevation of station, call letter ID, and a meteorological point observation quality-control process name. Following is a sample header:

Station ID# 893240, Lat= -80.0000S, Lon=120.000W, Synoptic observation from a fixed land station
Station Elevation = +15309 Meters, Call Letters = Missing, Quality Control Process = V082

The first five columns of data (year, mo, da, hr, and mn) are year, month, day, hour, and minute, respectively. The remaining columns are described in the following table:

Column Descriptions
Name Definition Units Scaling Factor Minimum Data Value Maximum Data Value Missing Flag Value
dir Wind Direction Degrees 1 1 360 999
dqc Wind Direction Quality Code 0 = No Check
1 = Good
2 = Suspect
3 = Erroneous
9 = Missing
1 0 9 9
wtype Wind Observation Type Code C: Calm
N: Normal
Q: Squall
V: Variable
9: Missing
n/a n/a n/a 9
wsp Wind Speed Meters per second 10 0 900 9999
sqc Wind Speed Quality Code 0 = No check
1 = Good
2 = Suspect
3 = Erroneous
9 = Missing
1 0 9 9
cig Ceiling Determination Code A: Aircraft
B: Balloon
C: Statistically derived
E: Estimated
M: Measured
R: Radar
W: Obscured
9: Missing
n/a n/a n/a 9
hqc Sky Condition 'Ceiling and Visibility Okay' (CAVOK) code N: No
Y: Yes
n/a n/a n/a n/a
visby Visibility Meters 1 0 1600000
Note: values greater than 160000 are entered in as 160000
999999
dqc Visibility Quality Code 0 = No check
1 = Good
2 = Suspect
3 = Erroneous
9 = Missing
1 0 9 9
vv Visibility Variability Code
N: Not variable
V:  Variable
n/a n/a n/a n/a
vqc Visibility Variability Quality Code 0 = No check
1 = Good
2 = Suspect
3 = Erroneous
9 = Missing
1 0 9 9
dbt Air Temperature Degrees celsius 10 -932 618 9999
bqc Air Temperature Quality Code 0 = No check
1 = Good
2 = Suspect
3 = Erroneous
9 = Missing
1 0 9 9
dpt Dew Point Temperature Degrees celsius 10 982 368 9999
pqc Dew Point Temperature Quality Code 0 = No check
1 = Good
2 = Suspect
3 = Erroneous
9 = Missing
1 0 9 9
slp Sea Level Pressure Hectopascals 10 8600 10900 99999
sqc Sea Level Pressure Quality Code 0 = No check
1 = Good
2 = Suspect
3 = Erroneous
9 = Missing
1 0 9 9

JPEG graphs of meteorological variables throughout the time series accompany the ASCII data.

File and Directory Structure

The following figure shows the directory structure on the FTP site. Data are first organized into "data" and "browse" directories, each containing "arctic" and "antarctic" directories, which then contain directories for each weather station ID. Each file represents one year of data for one station.

Directory structure

File Naming Convention

An example convention for a data file is "040010_2001.dat," where "040010" is the station ID and "2001" is the four-digit year. Browse files follow the same convention, except with a .jpg file extension.

File Size

Data files range from 1 KB to 1.5 MB.

Spatial Coverage

The Spatial Coverage table lists dates of coverage for each station. Surface observations fall within the following bounding coordinates:

Arctic:
Southernmost Latitude: 59.983
Northernmost Latitude: 83.633
Westernmost Longitude: -73.167
Easternmost Longitude: -13.583

Antarctica:
Southernmost Latitude: -90
Northernmost Latitude: -60.717
Westernmost Longitude: 0
Easternmost Longitude: 178.72

Spatial Coverage Map

Greenland Automatic Weather Stations
Greenland Automatic Weather Stations
    Antarctica Automatic Weather Stations
Antarctica Automated Weather Stations

Temporal Coverage

The Spatial Coverage table also lists dates of coverage for each station.

Temporal Coverage Map

See Temporal Coverage by Station.

Temporal Resolution

Data from automated weather stations were recorded on an hourly basis; temporal resolution from other sources varies from station to station.

Parameter or Variable

See the Column Descriptions table.

Sample Data Record

Following are the first nine lines of the file "040180_1992.dat." Columns are described in the Format section of this document.

	
Station ID# 040180, Lat= 63.9670N, Lon=22.6000W, METAR Aviation routine weather report
Station Elevation = +0054B Meters, Call Letters = BIKF , Quality Control Process = V082
 
year  mo da hr mn dir dqc wtype wsp sqc cig hqc visby dqc vv  vqc  dbt bqc  dpt pqc  slp sqc
1992  1  1  0  0 250  1      N   98 1  1200 1   35000  1   N   1     3 1   -82  1   9777  1
1992  1  1  0 30 240  1      N  118 1   450 1    1600  1   N   1   -10 1   -80  1  99999  9
1992  1  1  1  0 270  1      N   57 1  1200 1   11200  1   N   1   -10 1   -80  1  99999  9
1992  1  1  1 30 250  1      N   77 1   360 1    1600  1   N   1   -20 1   -90  1  99999  9
1992  1  1  2  0 220  1      N   36 1   390 1    6000  1   N   1   -20 1   -90  1  99999  9

Error Sources

NCDC, AFCCC, and FNMOD (2000) state that data contain a "minimal number of errors, decode errors, and reporting errors (by station) -- less than 0.1% of observations affected overall. Most errors corrected/eliminated by quality control software."

Quality Assessment

NCDC, AFCCC, and FNMOD (2000) state that "data have undergone extensive automated quality control, and additional manual quality control for U.S. Air Force stations, U.S. Navy stations, and U.S. National Weather Service stations." Upon extracting and reformatting the data, Julienne Stroeve (NSIDC) checked that all data values were correctly filled in.

3. Data Access and Tools

Data Access

Data are available via FTP.

Volume

The complete data set is approximately 2.3 GB.

Related Data Collections

4. Data Acquisition and Processing

Sensor or Instrument Description

Data originate from various sources such as synoptic, airways, Meteorological Routine Weather Report (METAR), Supplementary Marine Reporting Station (SMARS), and observations from automated weather stations.

Data Source

These data were extracted from the Air Force Combat Climatology Center (AFCCC)'s DATSAV3 database, which is part of the larger Integrated Surface Hourly (ISH) database, available from the National Climatic Data Center. The ISH database is composed of worldwide surface weather observations from about 20,000 stations, collected and stored from sources such as the Automated Weather Network (AWN), the Global Telecommunications System (GTS), the Automated Surface Observing System (ASOS), and data keyed from paper forms (NCDC 2000).

Processing Steps

Lott, Baldwin, and Jones (2001) describe the processing steps used to assemble the ISH database. Each station record has a set of mandatory fields that are common across all records, along with a set of optional fields that are often inconsistent in format. Stroeve (NSIDC) extracted only the mandatory fields from each record and wrote the data to tab-delimited ASCII format.

5. References and Related Publications

AFCCC. 1998. Documentation for DATSAV3 surface hourly data. Asheville, NC: AFCCC. View PDF file.

Lott, N., R. Baldwin, and P. Jones. 2001. The FCC Integrated Surface Hourly Database, NCDC Technical Report 2001-01. Asheville, NC: NCDC. View PDF file.

NCDC, AFCCC, and FNMOD. 2000. Federal Climate Complex data documentation for integerated surface hourly data. Asheville, NC: National Climatic Data Center. View PDF file.

6. Document Information

Acronyms and Abbreviations

The following acronyms and abbreviations are used in this document.

AFCCC Air Force Combat Climatology Center
ASOS Automated Surface Observing System
AWN Automated Weather Network
EOSDIS Earth Observing System Data and Information System
FCC Federal Climate Complex
FNMOD Fleet Numerical Meteorology and Oceanography Detachment
GTS Global Telecommunications System
IHS Integrated Surface Hourly
METAR Meteorological Routine Weather Report
NOAA National Oceanic Atmospheric Administration
NCDC National Climatic Data Center
NSIDC National Snow and Ice Data Center
SMARS Supplementary Marine Reporting Station

Document Creation Date

December 2003

Document Revision Date

December 2003

Document Review Date

December 2003

Document URL

http://nsidc.org/data/docs/daac/nsidc0190_surface_obs.gd.html