Data Set ID:

Historical Arctic and Antarctic Surface Observational Data, Version 1

This product consists of meteorological data from 105 Arctic weather stations and 137 Antarctic stations, extracted from the National Climatic Data Center (NCDC)'s 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.

This is the most recent version of these data.

BASIC Level of Service

Data: Data integrity verified

Documentation: Key metadata and links to supporting documentation available

User Support: Assistance with data access and basic data usage

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Data Format(s):
  • ASCII Text
Spatial Coverage:
N: 83.633, 
N: -60.717, 
S: 59.983, 
S: -90, 
E: -13.583, 
E: 178.72, 
W: -73.167
Spatial Resolution:Not SpecifiedSensor(s):AWS
Temporal Coverage:
  • 1 January 1913 to 31 December 2002
Temporal ResolutionNot specifiedMetadata XML:View Metadata Record
Data Contributor(s):Julienne Stroeve, Christopher Shuman

Geographic Coverage

Once you have logged in, you will be able to click and download files via a Web browser. There are also options for downloading via a command line or client. For more detailed instructions, please see Options Available for Bulk Downloading Data from HTTPS with Earthdata Login.

As a condition of using these data, you must cite the use of this data set using the following citation. For more information, see our Use and Copyright Web page.

Julienne Stroeve and Christopher Shuman 2004. Historical Arctic and Antarctic Surface Observational Data, Version 1. [Indicate subset used]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. doi: [Date Accessed].

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Detailed Data Description


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
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.

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File and Directory Structure

The following figure shows the directory structure on the HTTPS 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

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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.

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File Size

Data files range from 1 KB to 1.5 MB.

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The complete data set is approximately 2.3 GB.

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Spatial Coverage

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

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

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
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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.

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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
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Software and Tools

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.

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Data Acquisition and Processing

Data Acquisition Methods

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).

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Derivation Techniques and Algorithms

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.

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."

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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.

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References and Related Publications

Contacts and Acknowledgments

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

Document Information


December 2003


December 2003

No technical references available for this data set.

How To

V0 Programmatic Data Access Guide
Data from the NASA National Snow and Ice Data Center Distributed Active Archive Center (NSIDC DAAC) can be accessed directly from our HTTPS file system. We provide basic command line Wget and curl instructions for HTTPS file system downloads below. For questions about programmatic access to NSIDC... read more