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Data Set ID:
NSIDC-0008

Historical Arctic Rawinsonde Archive, Version 1

The Historical Arctic Rawinsonde Archive (HARA) contains millions of vertical soundings of temperature, pressure, humidity, and wind, representing all available rawinsonde ascents from Arctic land stations poleward of 65 degrees North. HARA includes soundings from the beginning of record through mid-1996. Most stations began recording soundings in the late 1950s, but a few began in 1947 or 1948.

Geographic Coverage

Parameter(s):
  • Atmospheric Temperature > Air Temperature
  • Atmospheric Pressure
  • Altitude > Geopotential Height
  • Atmospheric Water Vapor > Humidity
  • Atmospheric Water Vapor > Water Vapor > Humidity
  • Atmospheric Temperature > Surface Air Temperature
  • Atmospheric Winds > Surface Winds > Wind Direction
  • Atmospheric Winds > Upper Level Winds > Wind Direction
  • Atmospheric Winds > Surface Winds > Wind Speed
  • Atmospheric Winds > Upper Level Winds > Wind Speed
Spatial Coverage:
  • N: 90, S: 65, E: 180, W: -180

Spatial Resolution:
  • Varies
Temporal Coverage:
  • 10 November 1947 to 30 June 1996
Temporal Resolution: Varies
Data Format(s):
  • ASCII Text
Platform(s) BALLOONS, GROUND STATIONS
Sensor(s): RAWINSONDES
Version: V1
Data Contributor(s): Jonathan Kahl, Mark Serreze, Spencer Shiotani
Data Citation

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.

Serreze, M. C., J. D. Kahl, and S. Shiotani. 1997. Historical Arctic Rawinsonde Archive, Version 1. [Indicate subset used]. Boulder, Colorado USA. NSIDC: National Snow and Ice Data Center. doi: http://dx.doi.org/10.5067/FQZA3330CVPO. [Date Accessed].

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Notice: 

This data set is now on FTP so references to CD-ROM are historic and no longer applicable.

Detailed Data Description

This document describes the Historical Arctic Rawinsonde Archive, compiled by Principal Investigators J. Kahl, M. Serreze, and R. Schnell, under support from the National Oceanic and Atmospheric Administration's Climate and Global Change Program (Grant NA85RAHO5066), the Electric Power Research Institute (Grant RP2333-07), the National Science Foundation (Grant DPP-8822472), and the NSIDC Distributed Active Archive Center. The archive comprises millions of vertical soundings of temperature, pressure, humidity, and wind, representing all available rawinsonde ascents from Arctic land stations poleward of 65 degrees North, from the beginning of record through mid-1996. For most stations, the record begins in 1958, but a few begin as early as 1947 or 1948. The archive is presented in ASCII format that may be easily processed by most types of computers. Coverage is relatively uniform, except for the interior of Greenland. Typically, 20 to 40 levels are available in each sounding. HARA documentation is provided in the FTP directory and in hard copy (NSIDC Special Report 2, 1992). The FTP directory contain software (Fortran and C) for retrieval of sounding data subsets. The original soundings were obtained from the National Center for Atmospheric Research (NCAR), Boulder, Colorado and the National Climatic Data Center (NCDC) of NOAA in Asheville, North Carolina.

Objectives/Purpose

The archive is useful for meteorological and climatological research, applying to polar studies and investigations of global climate change. The archive is designed to facilitate climate analyses requiring sounding time series at multiple stations throughout the arctic.

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Format

The data fields are in ASCII text format. Each sounding in the archive consists of a header record, followed by a number of data records. Typically 20 to 40 levels are available in each sounding. Appendix 2 includes an example of a sounding. The database is archived on FTP.

We recognize that users usually desire a database of this type to be sorted in one of two ways:

  1. Synoptic-ordered: One time period -- all stations; followed by the next time period -- all stations, etc.
  2. Station-ordered: A complete time series for station #1; followed by a complete time series for station #2, etc.

As a compromise, the following file structure is used: One file contains a one-year time series of soundings for one station. Users requiring station-ordered data can simply append individual one-year files to obtain a station history of a length that is suitable to their needs. Users requiring synoptic-ordered data may extract files for several stations corresponding to a particular year, then extract from them the necessary dates and times.

The variables and formats of the individual soundings are as follows:

Header Record

1. STATION
World Meteorological Organization (WMO) station identification number. All stations are ascribed a WMO number, with the exception of "SHIP M" (Figure 1; Appendix 1). This was arbitrarily assigned a station code of 80000.
2. LATITUDE
Latitude of the station in degrees and hundredths of a degree (N).
3. LONGITUDE
Longitude from 0 to 360 degrees, in degrees and hundredths of a degree, measured counterclockwise from the Greenwich Meridian as viewed from the pole.
4. YEAR
Year of sounding.
5. MONTH
Month of sounding.
6. DAY
Day of sounding.
7. HOUR
Hour of sounding. This is usually 0000 GMT, 0600 GMT, 1200 GMT, or 1800 GMT. Prior to 1952, however, soundings reported at 0800 GMT and 1400 GMT.
8.-10. PROC1, PROC2, PROC3
Special processing codes. These are only available for sounding type ID=1. They provide information on special processing, and whether soundings were manually or automatically processed (see Appendix 4). For all other sounding types (ID=2, 3, 4 or 5), PROC1, PROC2, and PROC3 are assigned blanks. Pages 6 and 7 of Office Note 29 (Mulder (1977)), which describe these codes for the ID=1 data, are given in Appendix 5.
11. REP
Report type. This will always be assigned the value of 011 or 0. It denotes that the sounding was taken at a fixed land station.
12. ELEVATION
Station elevation in meters above mean sea level. Missing values are 99999.
13. INSTRUMENT
Instrument type used in sounding (e.g., Vaisala, Metox). This information is only available for ID=1 soundings. Page 9 of Office Note 29 (Mulder (1977)), describing the instruments for ID=1 soundings, is included in Appendix 5. For all other sounding types, this variable is assigned a value of 0.
14. NLEVELS
The number of levels reported in the sounding; i.e., the number of data records following the header record.
15. ID
An identification code indicating the sounding's original source. Values correspond to the listing in the Data Acquisition Methods section. These identification values are important because the quality codes vary with each sounding type (Appendix 4).

The FORTRAN format of the header record (15 variables) is as follows: FORMAT (A5, 2I5, 1X, 4I2, 1X, 3A1, I3, I5, I2, 1X, I3, 1X, I1).

Data Records

The variables are as follows:

1. PRESSURE
Pressure in tenths of millibars. Data from most stations are rounded to the nearest 1 mb. Missing values are 99999.
2. GEOPOTENTIAL HEIGHT
Geopotential height of the pressure level in whole meters. Missing values are 99999.
3. TEMPERATURE
Temperature in tenths of a degree (degrees C). Missing values are 9999.
4. DEWPOINT DEPRESSION
Dewpoint depression in tenths of a degree (degrees C). Missing values are 999.
5. WIND DIRECTION
Wind direction, 0 to 360 degrees, measured clockwise from north (e.g., 90 degrees is east). Missing values are 999.
6. WIND SPEED
Wind speed in whole meters per second. Missing values are 999.
7.-15. QG, QG1, QT, QT1, QD, QD1, QW, QW1, QP
Quality control flags for geopotential height (QG, QG1), temperature (QT, QT1), dewpoint depression (QD, QD1), winds (QW, QW1), and pressure (QP). The values of QG, QT, QD, QW, and QP depend on the sources of the sounding as identified by the value of ID (see Appendix 4). These vary considerably among the sources of the original soundings, and on whether the original processing was accomplished automatically (via computer) or manually (designated by "auto" or "man" in Appendix 4). QG1, QT1, QD1 and QW1 are additional quality code flags for geopotential height, temperature, dewpoint depression, and winds, based on our error-checking procedure, described earlier. Values are either 'P' (passed limits check) or 'F' (failed limits check). No limits check quality flag is given for pressure, as we used pressure as the test variable in the limits check. *(These additional codes are not available on Volume 5. Please see Revision below.)
16. LEVCK
A quality control flag set to 'P' if no errors were detected in the level for any variable, based on the limits check described above. If any errors were detected in the limits check, it is set to 'F'. *(This variable is not available on Volume 5. Please see Revision below.)
17. LTYPE
Code for level type (surface, significant, or mandatory). Only relevant for soundings of type ID=4 (see Appendix 4). For sounding types other than ID=4, the value is assigned a blank. This variable is not available on Volume 5. Please see Revision below.
18. LQUAL
Flag for quality of level. Only relevant for soundings of type ID=4 (see Appendix 4). This variable is not available on Volume 5. Please see Revision below.

The FORTRAN format of the data records (18 variables) are as follows: FORMAT (2(I5, 1X), I4, 1X, 3(I3, 1X), 2A1, 1X, 2A1, 1X, 2A1, 1X, 2A1, 1X, 4A1).

Revision

Experience has shown that the additional quality codes have limited value to the user. Starting with Volume 5, these codes are no longer provided. The columns corresponding to these codes simply appear as blanks. FORTRAN code that performs more comprehensive error-checking is available from M. Serreze.

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Sample Data Record

(THULE, GREENLAND: ID=4)

04202 765229125 59 1 1 0     11   63 0  23 4 
10040    31 -329  94  90   3 9P 9P 9P 9P 9P00
10000    62 -308  95  90   3 9P 9P 9P 9P 9P10
 9500   430 -277  79  70   3 9P 9P 9P 9P 9P90
 9000   819 -283  66 105   4 9P 9P 9P 9P 9P90
 8500  1227 -287  83 142   5 9P 9P 9P 9P 9P10
 8000  1660 -301  93 182   5 9P 9P 9P 9P 9P90
 7500  2130 -323  94 225   7 9P 9P 9P 9P 9P90
 7000  2602 -346  97 250   7 9P 9P 9P 9P 9P10
 6500  3130 -370 101 260  11 9P 9P 9P 9P 9P90
 6000  3668 -396 101 260  12 9P 9P 9P 9P 9P90
 5500  4260 -416 999 260  16 9P 9P 8  9P 9P90
 5000  4903 -437 999 270  18 9P 9P 8  9P 9P10
 4500  5600 -488 999 270  20 9P 9P 8  9P 9P90
 4000  6371 -541 999 270  24 9P 9P 8  9P 9P10
 3500  7219 -589 999 270  21 9P 9P 8  9P 9P90
 3000  8180 -620 999 270  18 9P 9P 8  9P 9P10
 2500  9312 -603 999 270  14 9P 9P 8  9P 9P10
 2000 10712 -588 999 260  14 9P 9P 8  9P 9P10
 1750 11545 -620 999 260  15 9P 9P 8  9P 9P90
 1500 12499 -616 999 260  15 9P 9P 8  9P 9P10
 1250 13624 -631 999 260  14 9P 9P 8  9P 9P90
 1000 14984 -670 999 260  10 9P 9P 8  9P 9P10
  800 16321 -698 999 260  10 9P 9P 8  9P 9P90
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Directory Structure

The directory structure design of the Historical Arctic Rawinsonde Archive (HARA) provides a logical path for locating the rawinsonde data. The data are stored in directories organized by year and World Meteorological Organization (WMO) station identification number. There is a separate DOCUMENT directory containing information about the HARA data and data formats, a SOFTWARE directory containing both C and FORTRAN source code that can be compiled and executed to retrieve a subset of the sounding data from a HARA FTP directory, and a CATALOG directory containing a catalog of the HARA data available to date.

                        HARA_VOLUME_#
		            |
                    ----------------------------------------------------
                    |                  |                |              |
                   DATA             DOCUMENT         SOFTWARE      CATALOG
                    |                  |                |              |
                    |              HARA.TOC             |              |
      --------------------...      INTRO.DOC            |           HARA.CAT
      |           |                SOURCE.DOC           |
    1948         1949 (Years...)   PROCESS.DOC          |
      |           |                FORMATS.DOC          |
  70026.48    70026.49             BIBLIO.DOC           |
  71072.48    71072.49             APPENDIX.DOC         |
  71074.48    71074.49             SOFTWARE.DOC         |
      .          .                 CD_ROM.DOC           |
      .          .                 HARA.CAT             |
      .          .                                      |
                                                        |
                                          ---------------------------
                                         DOS                      UNIX
                                          |                         |
                                   --------------            --------------
                                   |            |            |            |
                                FORTRAN         C          FORTRAN        C
                                  |             |           |             |
                             (FORTRAN         ( C        (FORTRAN       ( C
                              source         source       source       source
                               code)          code)        code)        code)

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Spatial and Temporal Coverage

Spatial Coverage

North polar regions:

  • Minimum latitude: 65N
  • Maximum latitude: 90N
  • Minimum longitude: 180W
  • Maximum longitude: 180E

Spatial Coverage Map

Station Locations
Figure 1. Station Locations

Temporal Coverage

The archive extends from the beginning of record through mid-1996. For most stations, the record begins in 1958; a few begin in 1947 or 1948.

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Application of the Data Set

Soundings are typically used in synoptic meteorology and for climatology.

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Software and Tools

Note: This data set is now on FTP so references to CD-ROM are historic and no longer applicable.

This document describes the access software that is in the FTP directory for the Historical Arctic Rawinsonde Archive (HARA). The purpose of this software is to familiarize the user with the structure of the data and to provide examples of software routines that can be used to subset and extract the data residing on the HARA FTP directory. Two versions of the access software are being supplied in the HARA FTP directory; one was written using the C programming language, the other using FORTRAN. Where appropriate, the differences between the two versions will be noted. This software can be compiled on either a UNIX or Microsoft Disk Operating System (MS-DOS) platform. The software was compiled and tested on an IBM PC using both Microsoft (MS) C and FORTRAN compilers. Use the following links to navigate this section:

Compiling the Source Code
Copy Source and Ancillary Files to Working Directory
   UNIX Environment
   MS-DOS Environment
Verify Mount Point for CD-ROM
   UNIX Environment
   MS-DOS Environment
Create the Executable File
   UNIX Environment
   MS-DOS Environment
Running the Program
   Interactive Mode
      Executing the Access Program
   Non-interactive Mode
Format Description of the Data Extracted from the HARA CD-ROM
Description of Files Produced Using the HARA CD-ROM Access Software
Listing of Arctic WMO Stations

Compiling the Source Code

Copy Source and Ancillary Files to Working Directory

The first step in preparing to compile the HARA CD-ROM access software is to copy the source files from the CD-ROM to the directory where the executable is to be built. If the mount point for the HARA CD-ROM is "/CDROM" and the working directory is "/usr/people/mydir," then issue the following command replacing <PLATFORM> with UNIX or DOS and <language> with either C or FORTRAN.

Transferring Files to a UNIX Environment

cp /CDROM/software/<PLATFORM>/<language>/* /usr/people/mydir

Files required to compile and execute the C version of the software include:

  • global.c
  • access.c
  • set0.c
  • set1.c
  • set2.c
  • myheader.h
  • makefileC
  • stationwmo.dat
  • infile.dat

Files required to compile and execute the FORTRAN version of the software include:

  • access.f
  • set0.f
  • set1.f
  • set2.f
  • makefileFOR
  • stationwmo.dat
  • infile.dat

NOTE: Files copied from the CD-ROM to a local UNIX disk retain the 'read-only' attribute of the files residing on the CD-ROM. In order to modify or edit these files the attributes have to be changed to permit 'write' access. To change the file attributes, type in the following UNIX command:

#chmod u+w *

Transferring Files to an MS-DOS Environment

copy l:\software\<PLATFORM>\<language>\* d:\mydir\*

Files required to compile and execute the C version of the software include:

  • global.c
  • access.c
  • set0.c
  • set1.c
  • set2.c
  • myheader.h
  • stationwmo.dat
  • infile.dat

Files required to compile and execute the FORTRAN version of the software include:

  • access.f
  • set0.f
  • set1.f
  • set2.f
  • stationwmo.dat
  • infile.dat
Verify Mount Point for CD-ROM
UNIX Environment

After the source code files have been copied to a working directory verify that the "fpath" variable is defined correctly in the source file set1.c (set1.f for FORTRAN). This variable defines the path to the rawinsonde data located on the CD-ROM. The "openr()" function located in the set1 module was coded with a default value for "fpath." If the mount point is defined other than "/CDROM" then the value of "fpath" must be changed in the set1 source file.

In the C source file set1.c, the line

	fpath[] = "/CDROM/data/19"

defines the value of the "fpath" variable.

In the FORTRAN source file, set1.f, the line

	fpath = '/CDROM/data/19'//ext//"/"//idst(icnt)//'.'//ext

defines the value of the "fpath" variable.

If for some reason the mount point for the HARA CD-ROM cannot be defined as "/CDROM," then the set1 source file must be edited, replacing the text string "/CDROM" on the line defining the "path" variable with the text string defining the mount point for the HARA CD-ROM.

MS-DOS Environment

After the source code files have been copied to a working directory verify that the "fpath" variable is defined correctly in the source file set1.c (set1.f for FORTRAN). This variable defines the path to the rawinsonde data located on the CD-ROM. The "openr()" function located in the set1 module was coded with a default value for "fpath." If the mount point is defined other than "l:\" then the value of "fpath" must be changed in the set1 source file.

In the C source file set1.c, the line

	fpath[] = "l:\\data\\19"

defines the value of the "fpath" variable.

In the FORTRAN source file, set1.f, the line

	fpath = 'l:\data\19'//ext//"\"//idst(icnt)//'.'//ext

defines the value of the "fpath" variable.

If for some reason the mount point for the HARA CD-ROM cannot be defined as "l:\", then the set1 source file must be edited, replacing the text string "l:\" on the line defining the "fpath" variable with the text string defining the mount point for the HARA CD-ROM.

Create the Executable File
UNIX Environment

A makefile is included with the source files that were copied into the working directory (refer to 1.1 above). Rename the appropriate makefile (MakefileC or MakefileFOR) to "makefile." By issuing the command "make" at the shell prompt the source files will be compiled and linked into an executable file named "access."

MS-DOS Environment

There are multiple files containing subroutines that must be compiled and linked together. Refer to your compiler manual for exact instructions on how to accomplish this. The main program is named access.<c or for> with subroutines in files set0, set1, set2 ,(and global.c for C only).

The following command couples the required C-source modules using the MS C compiler and links the resulting object files creating the executable file, "ACCESS.EXE."

	D:\>CL ACCESS.C SET0.C SET1.C SET2.C GLOBAL.C 

Running the Program

Once the executable file has been created and the CD-ROM path has been verified the program should be ready to execute. There are two different modes in which the access program can be implemented. One is the interactive mode which requires the user to respond to a series of questions that request attributes, such as spatial and temporal ranges, to define the subset of data to be extracted from the CD-ROM. The other mode requires the user to prepare a text file containing the attributes of the subset to be extracted from the CD-ROM. An example of a file containing parameters that define a subset of HARA data to be transferred from CD-ROM to a working directory is included with the distribution (Section 2.2).

Interactive Mode

The access program should be run interactively until the user becomes familiar with the structure of the data set and the format of the output the program generates. The user is required to type in the responses to each query made by the access program before the program begins transferring data from the CD-ROM. The following table describes the parameters required as input to the access program.

Parameter	Range                        
---------------	----------                   
WMO Station ID     00000-99999
Latitude           0-90  
Longitude          0-360
Year               48 - 69  (Volume 1)          
		     70 - 79  (Volume 2)          
		     80 - 87  (Volume 3)          
Month              1-12                         
Hour               0-24  (GMT)
Pressure Level     0-1200 (mb)

Note that the latitude and longitude of a station can vary slightly due to irregular station location changes.

Executing the Access Program in the Interactive Mode

To run either the C or FORTRAN version of the access program in the interactive mode simply type "access" at the shell prompt.

Example:

	#access
Non-interactive Mode

This mode provides quicker and easier execution of the access program. In order to use this mode the user must prepare a file with all of the parameters that define the subset of the data on CD-ROM that is to be extracted. Samples of the parameter file (infile.dat) are included with the distribution. One of the sample files for the non-interactive mode is to be used with the FORTRAN version of the access program, the other with the C version.

FORTRAN Version of infile.dat:
2               !interaction mode (1 for batch 2 for interactive)
1               !request specification (1 for WMO 2 for lat-long)
72948           !station name(1 value) or lat-long range(4 values)
48 69           !year range (2 values)
1 12            !month range(2 values)
0 24            !hour range(2 values)
2               !mandatory level flag (1 for mandatory pressure levels else 2)
0 1200          !pressure range (2 values)
1               !output file flag (1 for multiple files 0 for 1 file)

C Version of infile.dat:
2           !request specification (1 for WMO 2 for lat-long)
0 90 0 360  !station name(1 value) or lat-long range(4 values)
48 69       !year range (2 values)
1 12        !month range(2 values)
0 24        !hour range(2 values)
2           !mandatory level flag (1 for mandatory pressure levels else 2)
0 1200      !pressure range (2 values)

To execute the FORTRAN version of the access program in the non-interactive mode simply type "access" at the shell prompt. Observe that the parameter file must have the mode flag set to "1" for the access program to process the extraction request in the non-interactive mode.

To process the extraction request in the non-interactive mode using the C version of the access program enter "access" followed by the "-i" option followed by the name of the parameter filename at the shell prompt.

Example:

	#access -i infile.dat

Format Description of the Data Extracted from the HARA CD-ROM

The data extracted from the HARA CD-ROM retains the same format as the data residing on the CD-ROM. The information for each sounding is comprised of a header and a series of measurements, each measurement taken at a particular pressure level. The format for each sounding can be described by the following FORTRAN format statements.

The format for the header record is:

	FORMAT(A5,2I5,1X,4I2,1X,A3,I3,I5,I2,1X,I3,1X,I1)

while the format for each measurement in the sounding is:

	FORMAT(2(a5,1X),14,1X,3(13,1X),4(A1,A1,1X),2A1).

A sample of the structure of a sounding follows:


   Header: 
	  72948 702023530 69 5 2 0      0    5 0   9 5

   Sounding:
	  99999 99999 9999 999 999 999 9  9  9  9  9P
	   8500  1387    4   4 160  12 AP AP AP DP AP
	   7000  2929  -55   3 225   6 DP AP AP DP AP
	   5000  5489 -213  40 185  13 DP AP AP DP AP
	    500 99999 -549 999 999 999 9  AP 9  9  9P
	    440 99999 -507 999 999 999 9  9P 9  9  9P
	    320 99999 -531 999 999 999 9  9P 9  9  9P
	    300 99999 -523 999 999 999 9  CP 9  9  OP
	    230 99999 -503 999 999 999 9  9P 9  9  9P

For a complete description of the variables that correspond to HARA data formats see the Format section.

Description of Files Produced Using the HARA CD-ROM Access Software

The HARA CD-ROM access program produces the file "my_list.dat" each time the program executes. The file contains a list of the stations for which data are being extracted from the CDROM. This file is overwritten each time the access program is executed.

The default for presenting the data extracted from the HARA CD-ROM is to transfer the data into the file "outfile.dat" in the working directory. This file is overwritten each time the FORTRAN version of the access program is executed, whereas data are appended to this file each time the C version is executed. It is recommended that the file "outfile.dat" be renamed prior to or after each extraction process.

Besides the default for presenting the data extracted from the HARA CD-ROM, the user can specify the data be stored in multiple files. The access program partitions the extracted data into files containing only those soundings recorded for a single year that are associated with an individual station. For example, suppose the request was for an area that included five stations and the user is interested in retrieving only those soundings occurring between January and March for the years 1970 through 1974. Using the option to create multiple files, the results would be stored in 25 separate files (5 stations times 5 years = 25). The naming convention for files created using the multiple file option is to concatenate the WMO station identification number with the last two digits of the year and to append ".dat" as the file extension (e.g., 7002687.dat would contain sounding data recorded during 1987 at the station with the WMO identifier 70026).

To produce multiple files using the C version of the access program specify the "-o" option:

	#access -i infile.dat -o

To produce multiple files using the FORTRAN version of the access program in the non-interactive mode set the parameter on the last line in the parameter file to 1 (section 2.3).

Care should be taken to ensure that there is sufficient disk space to accommodate the data extracted from the HARA CD-ROM.

Listing of Arctic WMO Stations

A listing of the stations can be found in the stationwmo.dat file. An example of the contents of stationwmo.dat is listed below.

  # WMO    LAT  LONG  YR ID STATION NAME 

1 71072  7623 24068 48  3 MOULD BAY, NT          CANADA 
2 71074  7868 25647 48  3 ISACHSEN, NT           CANADA
3 71917  8000 27407 48  3 EUREKA, NT             CANADA
4 71918  7303 27485 48  3 ARCTIC BAY, NT         CANADA
5 71924  7472 26504 48  3 RESOLUTE BAY, NT       CANADA
6 71938  6782 24487 48  3 COPPERMINE, NT         CANADA
7 70026  7130 20322 48  4 BARROW, AK             ALASKA

1 71072  7623 24068 49  3 MOULD BAY, NT          CANADA
2 71074  7868 25647 49  3 ISACHSEN, NT           CANADA
3 71917  8000 27407 49  3 EUREKA, NT             CANADA
4 71924  7472 26504 49  3 RESOLUTE BAY, NT       CANADA
5 71938  6782 24487 49  3 COPPERMINE, NT         CANADA
6 70026  7130 20322 49  4 BARROW, AK             ALASKA

The column labeled # represents the number of the file associated with a single year and is used as a counter to track the number of stations contributing sounding data for a particular year. For example, the HARA disk contains rawinsondes measured from seven (7) stations during 1948.

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Data Acquisition and Processing

Data Acquisition Methods

Data represent one-dimensional vertical soundings taken at land stations north of 65 degrees latitude, each including measurements of pressure, temperature, winds, and humidity at various atmospheric levels. The archive consists of all available Arctic rawinsonde data from fixed-position (mostly land) stations north of 65 degrees N. Data from drifting ice islands, ships, and aircraft dropsondes have been assembled as a separate archive.

Soundings data were obtained from the National Center for Atmospheric Research (NCAR) in Boulder, Colorado, and the National Climatic Data Center (NCDC) in Asheville, North Carolina. Five original archives were used to compile the database. These sources are assigned identification codes (ID) 1 through 5.

  • (ID=1) Asian Arctic, 1976-87; all stations subsequent to 1987: The original data, obtained from NCAR, is described by Mulder (1977). For the period 1976-87, ID=1 soundings represent a subset of the NCAR archive for Soviet and Scandinavian stations and "Ship M", a moored ship in the Norwegian Sea.
  • (ID=2) Victor Starr, 1958-63: This was the original archive compiled by Professor Victor Starr of the Massachusetts Institute of Technology in the late 1960s. It contains soundings from 75 stations throughout the Arctic. Up to 27 fixed pressure levels (including the surface) are reported. These data were obtained from NCAR.
  • (ID=3) Canadian Stations: This set contains soundings from Canadian Arctic stations. The record for some stations begins as early as 1948, but most stations started reporting regularly in the early to mid 1950s. These data were obtained from NCAR.
  • (ID=4) Alaska and Thule, Greenland: The record begins in 1947 for Barrow, Alaska; in 1952 for Barter Island, Alaska; and in 1952 for Thule, Greenland. These data were obtained from NCDC.
  • (ID=5) Asian Arctic, 1962-75: Similar to ID=1 but in a slightly different original format and containing fewer stations. The original data, obtained from NCAR, is described by Nielon (1964).

A considerable amount of overlap exists between original data sources. We have made an effort to choose the best available data from each original archive, based on error analyses and completeness of the soundings.

Appendix 1 lists all stations for which soundings are available. In the appendix, the year column indicates that sounding data are available for at least part of a given year. Millions of soundings are available, covering at least a 30-year period for most stations.

The station locations are shown in Figure 1. Note that the coverage is relatively uniform, with the exception of the interior of Greenland. Depending on the station, soundings are available from one to four times daily at 0000 GMT, 0600 GMT, 1200 GMT and 1800 GMT. Most often, reports are available at 0000 GMT and 1200 GMT. Prior to 1952, reporting times were 0800 GMT and 1400 GMT.

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Instrument Description

The instrumentation used to collect these data were Rawinsondes. Rawinsondes are balloon-borne instruments. The balloons are made of natural or synthetic rubber, which expand as they ascend, and eventually burst. For more information, please see the NSIDC Historical Arctic Rawinsonde Archive (HARA) Radiosonde Systems web page. See also Elliot and Gaffen (1991) and Garand et al. (1992).

Note: The instrument type used in sounding (whether Vaisala, Metox, etc.) is only available for ID=1 soundings. See Appendix 5: Additional Quality Codes for special processing procedures.

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Sort/Merge Routines

All original data except those corresponding to ID=1 and ID=5 (Asian data through 1987 and all data from 1988, onward) were received already sorted by decreasing pressure. ID=1 and ID=5, however, were not sorted by decreasing pressure and, therefore, required some special processing. Each original sounding was sorted into five categories:

  1. temperature, dewpoint depression, geopotential height and winds at mandatory pressure levels;
  2. temperature, dewpoint depression and winds at variable pressure levels;
  3. winds at variable pressure levels;
  4. winds at variable geopotential heights (this category was generally reported infrequently); and
  5. tropopause data.

Pressure levels are often repeated in this format. For example, while the first level in categories 2, 3, and 4 is always the surface, each category contains different information. At other times, what was reported as a mandatory level was also repeated as a significant level. Typically, two to four repeat levels were found for each sounding. To make these data compatible with the soundings from other sources, each sounding was passed through a sort/merge program.

The sort/merge program worked as follows: Each sounding was first sorted by decreasing pressure, then by increasing geopotential height. Repeat levels were flagged, based on identical values of pressure or geopotential height. The most complete record possible for each repeat level was then assembled. The first occurrence of any repeat value and its associated quality flag was retained (see Appendix 4 ). A drawback of the technique is that although two levels may be identified as repeats, temperature or wind values associated with repeat levels are sometimes slightly different. Retaining only the first occurrence will occasionally result in retaining a bad value. While in theory, this problem could have been eliminated by also inspecting each quality flag, the large volume of processing made this impractical. Spot checks indicate that this is only a minor problem. An artifact of the technique, however, is that since some of the quality flags indicate whether or not there is agreement between values at repeat levels (but do not indicate which level is correct), any flags retained relevant to between-category checks should be ignored (see Appendix 4).

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Error Checking

Data through 1991 were subjected to additional rudimentary error-checking routines. The design of the error-checking procedure was guided by three considerations:

  1. a desire to produce the highest-quality database possible;
  2. recognition that the large amount of raw data (106 soundings) prohibit exhaustive error-checking procedures, such as manually inspecting each sounding; and
  3. a desire to retain all data values present in the original soundings, thus allowing users to make their own determination of data quality.

The first step involved flagging obvious errors, such as negative wind speeds, negative geopotential heights, etc. All soundings were then passed through a seasonally adjustable limits check to screen additional errors. No guarantee is made that this routine identifies all errors and it is recognized that, on occasion, what is flagged as errors may in fact be valid data. As such, all obvious and probable errors are simply flagged, but the original data is retained.

The seasonally adjustable limits check worked as follows: All data from all stations for 1987 were stratified by season into 15 atmospheric layers bounded by pressure levels. Seasons are defined as December through February (winter), March through May (spring), June through August (summer) and September through November (autumn). Since all checks are based on pressure, no check on the pressure values, themselves, have been performed.

Initial frequency histograms of geopotential height, temperature, wind direction and wind speed were compiled for each layer and for each season in 1987. Extreme outliers were eliminated by discarding values more than four standard deviations from the respective means. Since wind speed does not follow a normal distribution, these values were first converted into log wind speed. Means and standard deviations for the remaining data were then recomputed. Using these data as representative sample means and standard deviations of the complete data set, we then flagged any value that was greater than plus or minus four standard deviations from the sample mean for the respective season and layer. The means and standard deviations used in the limits check are given in Appendix 3.

An implicit assumption in the error-checking routine is that the layer mean is representative of the mean for any level within that layer. Since a large number of atmospheric levels are used in the check, this is a tolerable assumption for testing temperature, wind direction and wind speed. It was found to be inappropriate for geopotential height; however, due to the logarithmic decay of pressure with increasing elevation.

To check the geopotential heights, we made use of this logarithmic relationship: Taking the log of pressure at the bottom (P1) and top (P2) of the layer in which the observed pressure (P) fell, a weight W was calculated:

W = [LOG(P)-LOG(P2)]/[LOG(P1)-LOG(P2)]. (1)

Next, ZL1 and ZH1, respectively, are defined as the lowest and highest allowable geopotential height at the base of the layer, and similarly, ZL2 and ZH2 as the lowest and highest allowed limits of the top of the layer (with limits taken as +/- 4 standard deviations from the mean). We then calculate ZL and ZH, which, by incorporating the weight W, define the limits of allowable geopotential height for the value of P:

ZL = W*[ZL1-ZH1] + ZH1 (2)

ZH = W*[ZL2-ZH2] + ZH2 (3)

The allowable value of Z at pressure level P in the sounding is, thus

As part of the error-checking routine, the 1000-millibar (mb) mandatory level was deleted if the corresponding geopotential height was less than the reported station elevation. Frequently situations were encountered in which a level was reported (i.e., pressure or geopotential height data were given), but all other variables had missing value codes. These levels were deleted.

Since atmospheric moisture can be highly variable, with considerable uncertainties in cold arctic conditions, the dewpoint depression data were simply screened to flag negative values and any values exceeding an arbitrary high threshold of 35 degrees C. Those wishing to use these data are referred to Elliot and Gaffen (1991), who provide an overview of problems in rawinsonde moisture data.

*Experience has shown that these error checks are of limited value to the user. They have, hence, been dropped for 1992, onward. FORTRAN code providing more comprehensive error checks is available from M. Serreze.

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Notes and Problems

Since each original database was in a different format, some adjustments and changes were required to make all soundings consistent. A number of problems were also noted during processing and as a result of manual spot checks. These are summarized below. Users encountering additional problems are urged to contact the authors of this document. All soundings subsequent to 1987 were obtained from NCAR tapes, which are in the ID=1 format.

Through a processing oversight on the part of M. Serreze, the pressure quality codes (QP) in Volumes 1 through 4 are missing and set to '9'. This problem has been corrected in Volume 5. Soundings in earlier volumes also appear to have some remaining problems related to the sort/merge routines. Again, these have been corrected in Volume 5.

ID=1: (Asian Arctic for 1976-1987; All stations for 1988, onward)

  1. Winds were originally in knots and were changed to meters per second.
  2. Longitudes were originally reported 0 to 360 degrees clockwise from the Greenwich Meridian. They were converted to 0 to 360 degrees counterclockwise as viewed from the North Pole.
  3. If categories 2, 3, and 4 were missing (the data categories for soundings of type ID=1 were discussed in the Data Acquisition Methods section above), the surface report was padded with missing values.
  4. The geopotential height of the surface level is not given in categories 2 through 4. The value has been set equal to the station elevation. However, reported station elevations do not always match those listed by WMO.
  5. Geopotential heights are usually available only for mandatory levels.
  6. If the indicated surface pressure is < 930 mb, the surface report is assumed to be missing.
  7. As noted previously, the requirement to merge duplicate levels means that any quality codes referring to agreement/disagreement between duplicate levels reported in different categories should be ignored.

ID=2: (Victor Starr, 1958-63)

Of all the original data, the Victor Starr soundings contained the most frequent errors. As such, we tried to use soundings from other sources whenever possible (i.e., during periods of overlap).

  1. Occasional surface reports with a value of 1000 mb should be present in any large sounding archive. Very few are noted in the original data, however. It is suspected that, at some point in time, 1000-mb surface reports were lost due to a processing error.
  2. Numerous reported surface pressures from 950 to 960 mb were encountered. In most cases, these must be errors. While such levels will often be flagged as errors on the basis of the geopotential height limits check, many were observed to pass this check.
  3. Temperature values were frequently flagged by the limits check algorithm. Surface temperature values in these situations were sometimes above 20 degrees C, with suspiciously high values throughout the profiles.
  4. Winds were originally reported in U and V components. They were converted to speed (meters per second) and direction (0-360 degrees).
  5. At times, the highest reported level had a geopotential height of 0 m. Temperatures also appear bogus in these cases. These are flagged as errors. The problem seems to only occur when 27 levels (the maximum possible) are reported. This appears to be a problem with the original data, and may have resulted from a bad array size.
  6. Errors are particularly common at 1200 GMT. The presence of a systematic error in the original processing is suspected. These soundings should be viewed with caution.

ID=3: (Canadian)

  1. The geopotential height of the surface report and the station elevation were supplied in the original sounding. Situations were frequently encountered in which the geopotential height at the surface was lower than the station elevation. Also observed were cases in which the surface geopotential height was greater than the station elevation.
  2. Surface pressure reports are sometimes shown as higher than the adjacent level by approximately 0.1 mb. (Only with ID=3 data are surface pressures commonly given to nearest 0.1mb.) However, the adjacent level shows geopotential height lower by 1 to 2 m.
  3. In the original tapes, the five-digit code for the Canadian stations had a '2' or '4' as the second byte (variable STATION in the header record). The second byte was changed to '1' to match WMO codes.
  4. Wind speed was originally in knots, and was converted to meters per second.

ID=4: (Alaska and Thule, Greenland)

  1. As discussed earlier, these soundings have two additional quality codes LTYPE (type of level, e.g., significant, mandatory, surface, etc.) and LQUAL (overall quality code for each level). LQUAL should not be confused with LEVCK, which is the overall quality code for the level based on our limits check used through 1987.
  2. Wind speed was originally in knots, and was converted to meters per second.
  3. Original moisture data were reported as relative humidity, and were converted to dewpoint depression.
  4. In some early soundings, a 1000-mb level is reported as a mandatory level even when the surface pressure is < 1000 mb.

ID=5: (Soviet, 1962-75)

  1. If categories 2, 3, or 4 were missing (the data categories for soundings of type ID=5 are discussed in Section 3a above), the surface report was padded with missing values.
  2. If categories 2, 3 ,or 4 were available, but the indicated surface pressure was < 930 mb, the surface report was assumed to be missing, and was padded with missing values.
  3. As for ID=4, longitude values were converted to 0 to 360 degrees counterclockwise as viewed from the pole.
  4. Wind speed was originally in knots, and was converted to meters per second.
  5. Station elevation was not included in the sounding reports until 12/16/63. All station elevations were set to missing for years before 1964.

See Error Checking.

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Appendices

Appendix 1. Summary of the Soundings Contained in the Historical Arctic Rawinsonde Archive, 1948-1990

East longitudes are positive; west longitudes are negative. 

STATION ID                                    LAT          LON      # OF
   NAME                       COUNTRY        DEG N         DEG E    SOUNDINGS         YEARS

1001  JAN MAYEN               NORWAY        70.93         -8.67     15561             58-57
1005  ISFJORD RADIO           NORWAY        78.07         13.63       983             58-62, 64, 66-68
1010  ANDOYA                  NORWAY        69.30         16.12        22             66-68
1020                                        80.05        -18.29      1237             58-63
1028  BJORNOVA                NORWAY        74.52         19.02     16972             58-87
1030                                        69.69        -19.02      2424             58-63
1152  BODO                    NORWAY        67.28         14.42     17005             58-87
2057  16LULEA/KALLAX          SWEDEN        65.60         22.10      5881             63-77
2185                                       66.55         22.13     10000             77-87
2836   SODANKYLA               FINLAN        67.37         26.65     25290             58-87
4202  THULE AFB               GREENL        76.53        -68.75     42617             52-87
4210  UPERNAVIK               GREENL        72.78        -56.17       221             62-64, 71-72
4220  EGEDESMINDE             GREENL        68.70        -52.75     16727             58-87
4230  HOLSTEINBORG            GREENL        66.92        -53.67        12             63, 68-69, 71
4231  SDR. STROMFJORD         GREENL        67.00        -50.80         4             62, 85
4310  NORD                    GREENL        81.60        -16.67      5512             58-73, 75, 77-79, 81, 84-85, 87
4320  DANMARKSHAVN            GREENL        76.77        -18.77     15450             58-87
4330  DANEBORG                GREENL        74.30        -20.22         7             68-70
4339  SCORESBYSUND            GREENL        70.48        -21.97      4819             80-87
4340  KAP TOBIN               GREENL        70.42        -21.97     11819             58-80
4360  ANGMAGSSALIK            GREENL        65.60        -37.63     16452             58-87
20046 GMO IM ET KRENKELYA     SOVIET        80.62         58.05     20826             58-87
20047                                       80.44         52.80      1649             58-63
20069 OSTROV VIZE             SOVIET        79.50         76.98     18358             58-87
20107 BARENTSBURG             SOVIET        78.07         14.22     20289             58-87
20274 OSTROV UEDINENIA        SOVIET        77.50         82.23     17337             58-87
20292 GMO IM EK FEDEROVA      SOVIET        77.72        104.28     19396             58-87
20353 MYS ZHELANIA            SOVIET        76.95         68.58     18207             58-87
20406                                       80.62         58.05         2             79
20667 IM POPOVA               SOVIET        73.33         70.03      8709             58-87
20674 OSTROV DIKSON           SOVIET        73.50         80.23     17487             58-87
20744 MALYE KARMAKULY         SOVIET        72.38         52.73     13088             58-63, 67-74, 76-87
20891 KHATANGA                SOVIET        71.98        102.27     16753             58-80, 83-87
21358 OSTROV ZOHOVA           SOVIET        76.15        152.83     15375             58-87


STATION ID                                    LAT          LON      # OF
   NAME                       COUNTRY        DEG N         DEG E    SOUNDINGS         YEARS

21432 OSTROV KOTELNY          SOVIET        76.00         137.90    18983             58-87
21504 OSTROV PREOBRAZHENIA    SOVIET        74.67         112.93    20447             58-87
21647 MYS SHALAUROVA          SOVIET        73.18         143.93    18181             58-87
21824 BUKHTA TIKSI            SOVIET        71.58         128.92    19476             58-87
21825 OSTROV MOSTAKH          SOVIET        71.53         129.92        2             87
21908 DZHALINDA               SOVIET        70.13         113.97        4             81, 87
21946 COKURDAH                SOVIET        70.62         147.88    11238             58-87
21965 OSTROV CHETYREKHSTOLBO  SOVIET        70.63         162.40    17650             58-87
21982 OSTROV VRANGELYA        SOVIET        70.97        -178.55    16430             58-87
22113 MURMANSK                SOVIET        68.97          33.05    23186             58-87
22165 KANIN NOS               SOVIET        68.65          43.30     1803             58-62
22205 ENA                     SOVIET        67.60          31.17        4             86-87
22217 KANDALASKSA             SOVIET        67.13          32.43    21051             58-87
22271 SOJNA                   SOVIET        67.88          44.13    20852             63-87
22408 KALEVALA                SOVIET        65.20          31.17        2             62
22522 KEM-PORT                SOVIET        64.98          34.78     5660             58-73
23022 AMDERMA                 SOVIET        69.77          61.68    18284             58-87
23074 DUDINKA                 SOVIET        69.40          86.17     2231             58-64, 66-67
23078 NORILSK                 SOVIET        69.32          88.22     8777             80-87
23130                                        0.             0.          6             61, 65
23146 MYS KAMENNY             SOVIET        68.47          73.60    18944             58-87
23162                                        0.             0.         10             60, 65
23205 NARJAN MAR              SOVIET        67.65          53.02    24628             58-87
23274 IGARKA                  SOVIET        67.47          86.57     5356             58-74
23330 SALE-KHARD (OBDORSK)    SOVIET        66.53          66.53    20461             58-87
23339 POLUY                   SOVIET        66.27          67.87       96             76-87
23383 AGATA                   SOVIET        66.93          93.47        2             62
23418 PECHORA                 SOVIET        65.12          57.10    23793             58-87
23472 TURUKHANSK              SOVIET        65.78          87.95    21946             58-87
23552 TARKO-SALE              SOVIET        64.92          77.82     1478             58-65
24125 OLENEK                  SOVIET        68.50         112.43    15175             58-87
24266 VERKHOYANSK             SOVIET        67.55         133.38    19425             58-87
24343 ZHIGANSK                SOVIET        66.77         123.40    21842             58-87
25042 AYON                    SOVIET        69.93         167.97     6272             58-63, 66-86
25123 CHERSKIY                SOVIET        68.80         161.28    18090             58-63, 68-87


STATION ID                                    LAT          LON      # OF
   NAME                       COUNTRY        DEG N         DEG E    SOUNDINGS         YEARS

25173 MYS SCHMIDT             SOVIET        68.92       -179.48     18478             58-87
25248 ILIRNEYJ                SOVIET        67.33        168.23         3             71
25282 VANKAREM                SOVIET        67.85       -175.83        73             80-87
25399 MYS UELEN               SOVIET        66.17       -169.83      7373             58-75
25400 ZYRIANKA                SOVIET        65.73        150.90     13294             63-87
25428 OMOLON                  SOVIET        65.23        160.50     13838             58-87
70026 BARROW, AK              ALASKA        71.30       -156.78     27713             48-87
70086 BARTER IS., AK          ALASKA        70.13       -143.63     24613             53-87
70133 KOTZEBUE, AK            ALASKA        66.87       -162.63      4869             62-75
70192 145UNIVERSITY EXP STA   USA           64.90       -147.90         2             73
71043 NORMAN WELLS, NT        CANADA        65.28       -126.80     23631             55-87
71051 SACHS HARBOUR, NT       CANADA        72.00       -125.27     22302             55-86
71072 MOULD BAY, NT           CANADA        76.23       -119.32     28243             48-87
71074 ISACHSEN, NT            CANADA        78.68       -103.53     21518             48-78
71081 HALL BEACH, NT          CANADA        68.78        -81.25     22020             64-87
71082 ALERT, NT               CANADA        82.50        -62.33     26745             50-87
71090 CLYDE, NT               CANADA        70.47        -68.62     13867             50-70, 72
71914 NANISIVIK, NT           CANADA        72.97        -84.53         2             62
71917 EUREKA, NT              CANADA        80.00        -85.93     28437             48-87
71918 ARCTIC BAY, NT          CANADA        73.03        -85.15      5697             48, 50-57, 62-64, 66
71924 RESOLUTE BAY, NT        CANADA        74.72        -94.95     29933             48-87
71925 CAMBRIDGE BAY, NT       CANADA        69.10       -105.13     13122             62-63, 68, 70-87
71938 COPPERMINE, NT          CANADA        67.82       -115.13     14132             48-70
71957 INUVIK, NT              CANADA        68.30       -133.48     19942             60-87
71968 SHINGLE POINT, YT       CANADA        68.93       -137.23      7056             50-60
80000 Ship "M"                              66.00          2.00     15521             62, 68, 73-87


TOTAL                                                              1,220,713


Appendix 2. Example of a Sounding (THULE GREENLAND, ID=4)

04202 765229125 59 1 1 0     11   63 0  23 4 
10040    31 -329  94  90   3 9P 9P 9P 9P 9P00
10000    62 -308  95  90   3 9P 9P 9P 9P 9P10
 9500   430 -277  79  70   3 9P 9P 9P 9P 9P90
 9000   819 -283  66 105   4 9P 9P 9P 9P 9P90
 8500  1227 -287  83 142   5 9P 9P 9P 9P 9P10
 8000  1660 -301  93 182   5 9P 9P 9P 9P 9P90
 7500  2130 -323  94 225   7 9P 9P 9P 9P 9P90
 7000  2602 -346  97 250   7 9P 9P 9P 9P 9P10
 6500  3130 -370 101 260  11 9P 9P 9P 9P 9P90
 6000  3668 -396 101 260  12 9P 9P 9P 9P 9P90
 5500  4260 -416 999 260  16 9P 9P 8  9P 9P90
 5000  4903 -437 999 270  18 9P 9P 8  9P 9P10
 4500  5600 -488 999 270  20 9P 9P 8  9P 9P90
 4000  6371 -541 999 270  24 9P 9P 8  9P 9P10
 3500  7219 -589 999 270  21 9P 9P 8  9P 9P90
 3000  8180 -620 999 270  18 9P 9P 8  9P 9P10
 2500  9312 -603 999 270  14 9P 9P 8  9P 9P10
 2000 10712 -588 999 260  14 9P 9P 8  9P 9P10
 1750 11545 -620 999 260  15 9P 9P 8  9P 9P90
 1500 12499 -616 999 260  15 9P 9P 8  9P 9P10
 1250 13624 -631 999 260  14 9P 9P 8  9P 9P90
 1000 14984 -670 999 260  10 9P 9P 8  9P 9P10
  800 16321 -698 999 260  10 9P 9P 8  9P 9P90


Appendix 3. Data for Seasonally-Adjustable Limits Check

Temperature (øC)
Pressure (mb)
at layer                Winter           Spring          Summer        Autumn

  Bottom   Top     Mean      SD      Mean    SD      Mean    SD     Mean   SD

  1200     951     -21.3     12.1     -4.9   10.1      5.0    6.6   -15.7  12.7
  950      901     -19.1      8.9     -6.0    8.6      3.1    6.8   -14.2   9.6
  900      851     -18.6      7.8     -7.4    7.6      0.5    6.2   -14.0   8.7
  850      801     -19.1      7.3     -8.6    7.1     -1.1    5.9   -14.6   8.0
  800      701     -22.3      6.9    -12.1    6.9     -5.5    5.8   -17.9   7.8
  700      601     -25.7      6.5    -15.8    6.7    -10.2    5.5   -21.1   7.4
  600      501     -35.1      6.7    -25.6    6.9    -19.5    6.0   -31.1   8.0
  500      401     -44.7      6.2    -36.0    7.0    -30.3    6.5   -41.2   7.8
  400      301     -54.1      4.8    -47.8    5.2    -44.7    6.2   -52.9   5.7
  300      201     -57.4      6.7    -50.6    5.9    -51.2    5.7   -55.6   5.3
  200      151     -56.3      8.4    -47.7    4.6    -47.1    4.3   -54.1   5.0
  150      101     -56.1      8.5    -48.3    4.1    -46.6    3.1   -55.2   4.7
  100      51      -56.5      9.4    -48.9    4.5    -47.0    3.6   -58.2   6.3
  50       21      -55.1      9.4    -47.4    5.9    -45.4    7.5   -59.6  10.2
  20       0       -50.8     10.1    -38.7   12.9    -38.3   13.0   -54.7  15.1


Geopotential height (m)

                  Winter            Spring         Summer           Autumn

  P (mb)     Mean        SD     Mean      SD    Mean     SD     Mean        SD

  1200           0        0         0      0        0     0         0        0
  1000         121      102       111     74       99    64        95       94
   850        1333      105      1386     79     1417    71      1330       97
   700        2769      123      2882    104     2954    91      2789      121
   500        5159      164      5368    155     5504   135      5217      177
   400        6668      191      6933    189     7108   167      6745      215
   300        8536      209      8859    217     9066   201      8629      251
   250        9695      207     10051    218    10261   206      9795      257
   200       11115      227     11517    216    11720   201     11225      256
   150       12949      218     13420    227    13628   202     13074      256
   100       15537      278     16099    251    16321   217     15667      274
    70       17809      330     18445    278    18685   231     17929      288
    50       19961      381     20659    314    20916   258     20046      316
    30       23236      454     24023    419    24293   473     23282      544
    20       25842      533     26687    592    26998   459     25776      594
    10       30313      573     31333    629    31607   629     30238      555
     1       40000      573     40000    573    40000   573     40000      573


Ln wind speed (with wind speed in ms-1)
Pressure (mb)

at layer              Winter            Spring           Summer        Autumn

  Bottom   Top     Mean      SD      Mean    SD      Mean    SD     Mean   SD

  1200     926     1.933     0.631   1.844   0.588   1.737   0.677  1.914  0.725
  925      776     2.246     0.564   2.049   0.549   2.023   0.555  2.218  0.592
  775      601     2.405     0.557   2.207   0.559   2.143   0.560  2.340  0.585
  600      451     2.692     0.581   2.528   0.597   2.412   0.573  2.605  0.596
  450      351     2.823     0.608   2.717   0.621   2.592   0.600  2.751  0.621
  350      276     2.830     0.636   2.783   0.649   2.748   0.633  2.792  0.667
  275      226     2.736     0.642   2.640   0.648   2.695   0.628  2.737  0.669
  225      176     2.586     0.618   2.357   0.612   2.401   0.580  2.590  0.619
  175      126     2.499     0.595   2.101   0.570   2.123   0.541  2.502  0.549
  125      86      2.519     0.621   1.888   0.534   1.853   0.522  2.523  0.499
  85       66      2.554     0.687   1.730   0.501   1.684   0.518  2.557  0.480
  65       46      2.617     0.744   1.694   0.463   1.622   0.528  2.626  0.502
  45       26      2.743     0.758   1.787   0.431   1.679   0.531  2.763  0.545
  25       16      2.840     0.747   1.912   0.433   1.753   0.559  2.891  0.575
  15       0       3.000     0.727   2.222   0.557   2.031   0.708  3.142  0.568

Appendix 4. Quality Codes

QG (Geopotential height)

ID=1: (Soviet, 1976-87)

Auto.  Man.
A	I  Passed vertical consistency check with tight limits.
B	J  Failed vertical consistency check and has not been recomputed.
C	K  Failed vertical consistency check and recomputed.
D	L  Failed vertical consistency check with tight limits and passed with loose limits.
E	M  Not assigned
F	N  Checked but did not pass vertical consistency checks with loose limits
G	O  Not assigned
Blank    $   Not specified
9	9  Corresponding data value missing

ID=2: (Victor Starr Data)
0	Not checked
1	Checked, reported values (presumably good data).
2	Interpolated value (presumably failed check or was missing and value was
              interpolated from next higher and lower value)
9           Corresponding data value missing

ID=3: (Canadian Data) 
Original quality codes were extremely confusing.  They were adjusted to correspond as closely as
possible to those given in ID=1:
A           Passed vertical consistency check with tight limits
B           Failed vertical consistency check with loose limits
C           Failed vertical consistency check and recomputed
9           Corresponding data value missing

ID=4: (Alaskan and Thule, Greenland)
0           Value is correct
1           Value is doubtful
2           Value is in error
3           Replacement value
4           Assumed or estimated value
9           Value not checked
8           Corresponding data value missing

Auto.  Man.
A        I  Passed vertical consistency check with tight limits
B        J  Failed vertical consistency check and has not been recomputed
C        K  Failed vertical consistency check and was recomputed
D        L  Failed vertical consistency check with tight limits, passed with loose limits
E        M  Not assigned
F        N  Checked but did not pass vertical consistency check with loose limits
G        O  Not assigned
Blank	Not specified 
8	8  Corresponding data value missing 
Additional Codes:
P           Undefined
$           Undefined

ID=5: (Soviet, 1962-75)
Original quality codes in NCAR documentation changed to be as close as possible to those for ID=1. 
Values are as follows:
Auto.   Man.

A        I  Passed vertical consistency check with tight limits
B        J  Failed vertical consistency check and has not been recomputed
C        K  Failed vertical consistency check and recomputed
D        L  Failed vertical consistency check with tight limits and passed with loose limits
O        O  No hydrostatic check done
9        9  Corresponding data value is missing

QT (Temperature)

ID=1: (Soviet, 1976-87)
            Same as for QG

ID=2: (Victor Starr)
            Same as for QG

ID=3: (Canadian Data)
            Same as for QG

ID=4: (Alaska and Thule, Greenland)
            Same as for QG

ID=5: (Soviet, 1962-75)         
            Same as for QG

QD (Dewpoint Depression)
ID=1: (Soviet, 1976-87)

Auto.    Man.
Blank    $  Not Specified

ID=2: (Victor Starr)
            Same as for QG

ID=3: (Canadian Data)
            Same as for QG with following addition:
S           "Statistical".  Original NCAR tapes contained values of relative humidity less than 0.  The
            original documentation stated that the minus sign indicated that the absolute value is
            "statistical", which we assume means that it is obtained from climatology.  We
            converted the absolute value of the relative humidity to dewpoint depression. 
            Generally, values depart considerably from values at adjacent levels.

ID=4: (Alaska and Thule Greenland)
            Same as for QG

ID=5: (Soviet, 1962-75)
            Same as for QG

QW (Wind Direction and Speed)
ID=1: (Soviet, 1976-87)
            Same as for QG

ID=2: (Victor Starr) 
            Same as for QG

ID=3: (Canadian Data)
            Same as for QG

ID=4: (Alaska and Thule, Greenland)
            Same as for QG

ID=5: (Soviet, 1962-75)
            Same as for QG

QP (Pressure)

ID=1: (Soviet, 1976-87)
Auto     Man
Q        Y  Base of stratum with missing data
R        Z  Top of stratum with missing data
T        1  Reported tropopause level
U        2  Not applicable (ignore)
V        3  Not applicable (ignore)
W        4  Maximum reported wind level is not at the terminating level
X        5  Maximum reported wind level is at the terminating level
Blank    $  Not Specified
9        9  Corresponding value is missing.

Note: For mandatory levels, all pressure quality flags are blank (not specified).

ID=2: (Victor Starr)
            Same as for QG

ID=3: (Canadian Data)
            No relevant values, all set to '9'

ID=4: (Alaska and Thule, Greenland)
            Same as for QG

ID=5: (Soviet, 1962-75)
            Same as for QG

LQUAL (Level Quality Code)

ID=1: (Soviet, 1976-87)
            All blanks (flag not applicable)

ID=2: (Victor Starr, 1958-64)
            All blanks (flag not applicable)

ID=3: (Canadian, 1948-87)
            All blanks (flag not applicable)

ID=4: (Alaska and Thule, Greenland)
0           Original values correct
1           Original values missing
2           Original value doubtful, a corrected level follows
3           Original values doubtful, uncorrected
4           Original values in error, a corrected level follows
5           Original values in error, uncorrected
6           Corrected level
9           Level not checked

Auto   Man.
A        I  Passed vertical consistency check with tight limits
B        J  Failed vertical consistency check and has not been recomputed
C        K  Failed vertical consistency check and has been recomputed
D        L  Failed vertical consistency check with tight limits and passed with loose limits
E        M  Not Assigned
F        N  Has been checked but did not pass vertical consistency checks with loose limits
G        O  Not assigned
blank       Not specified

Additional Flags:
H           Not relevant (ignore)
P           Not relevant (ignore)

ID=5: (Soviet, 1962-75)
            All Blanks (flag not applicable)

LTYPE (Level Type)
ID=1: (Soviet, 1976-87)
            All Blanks (flag not applicable)

ID=2: (Victor Starr, 1958-64)
            All blanks (flag not applicable)

ID=3: (Canadian, 1948-87)  
            All blanks (flag not applicable)

ID=4: (Alaska and Thule, Greenland)
0           Surface
1           Mandatory
2           Significant
3           Generated
4           Tropopause
5           Maximum wind
9           Other/unspecified

ID=5: (Soviet, 1962-75)
         All blanks (flag not applicable)

Appendix 5. Additional Quality Codes

PROC1, PROC2, PROC3 and INSTRUMENT. Taken from pages 6, 7 and 9 of Mulder (1977). 

PROC1

Assigned to indicate special processing procedures.

	PROC1

Value                  Meaning

   0		Report has been adjusted to map time by an NMC updating
		procedure.  Heights are referenced to some forecast level

   1		Report has been adjusted to map time by an NMC updating
		procedure.  Heights are referenced to 1000 mb level at sea level.

   8		Reported heights are referenced to 1000 mb level at sea level.

   9*		Reported heights are referenced to some forecast level.

		*Except for report type 061 (SIRS), this value means "missing" or not applicable

PROC2

Assigned to indicate the information specifying that the standard isobaric surfaces were located by use of pressure equipment, or that pressure equipment was not available and the wind data were reported at altitudes approximating the standard isobaric surfaces.

	PROC2
Value		Equipment

   0		Pressure instrument associated with wind-measuring equipment.
   1 or 5	Optical theodolite.
   0 or 2	Radio theodolite.
   3 or 7	Radar.
   4		Pressure instrument associated with wind-measuring equipment but
   		pressure element failed during ascent.
   6		Not assigned.
   8		Not assigned.
   9		Not specified.

PROC 3

Assigned to indicate results of processing.

	

Value		Meaning

   0		All parameters in the report have been processed automatically
		(no manual intervention).

   1		All parameters in the report have been obtained by manual
		intervention (no automatic processing).

   2		All parameters in the report have been obtained by manual
		intervention and all parameters agree with automatically
		processed values.

   3		All parameters in the report have been obtained by manual
		intervention and all parameters disagree with automatically
		processed values.

   4		All parameters in the report have been obtained by manual
		intervention and one or more parameters disagree with
		automatically processed values.

   5		One or more, but not all, parameters in the report have been
		obtained by manual intervention and all of these parameters
		agree with automatically processed values.

   6		One or more, but not all, parameters in the report have been
		obtained by manual intervention and all of these parameters
		disagree with the automatically processed values.

   7		Two or more, but not all, parameters in the report have been
		obtained by manual intervention and one or more parameters
		agree and one or more parameters disagree with the
		automatically processed values.

   8		Not assigned.

   9		Not specified.

Instrument Assigned to Indicate Instrument Type

Instrument 
   Value                   Description

     01	U.S. - ESSA External thermistor
     02	U.S. - ESSA External thermistor (Plateau stations)
     03	U.S. - An/AMT-4 Military external thermistor
     04	Finland - Vaissla
     05	France - Metox
     06	Portugal - Canada Model IV
     07	W. Germany - Graw H.50 (Corrected)
     08	U.S. - ESSA 403 MhZ Duct-type (WBAN
	corrections applied at station)
     09	Japan - Code sending
     10	E. Germany - Freiberg
     11	Britain - Kaw Mark IIB
     12	USSR - A-22-III (IV)
     13	U.S. - ESSA 403 MhZ Duct-type (WBAN correction not
	applied at station)
     98	NOAA-II (SIRS-B) Instrument 1
     97	NOAA-II (SIRS-B) Instrument 2
Background color on

References and Related Publications

Contacts and Acknowledgments

Serreze, M., J. Kahl, and S. Shiotani under support from the National Oceanic and Atmospheric Administration's Climate and Global Change Program (Grant A85RAH05066), the Electric Power Research Institute (Grant RP2333-07), and the National Science Foundation (Grant DPP-8822472).

Document Information

Document Authors

NSIDC Technical Writers

Document Creation Date

August 1997

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