TDF63 FORMAT DOCUMENTATION - NCDC Upper Air Digital Archives

TDF63 DOCUMENTATION for NCDC UPPER AIR DIGITAL FILES

(Revised September 12, 1995)

Note: This document is current as of the revision date shown above. However, periodic additions may be made in entries for individual elements. The appendices will be expanded as more data are processed from additional sources.

IDENTIFICATION PORTION (108 Characters)
=================================================================================== FIELD | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | ----------------------------------------------------------------------------------- ELEMENT | BEG | WMO NUM | STN | STN NUM | LAT | LONG | ELEV | YEAR | | REC | | IND | | | | | | ----------------------------------------------------------------------------------- #CHARS | # | XXXXXX | X | XXXXXXXX | XXXXXXXA| XXXXXXXXA | XXXXX | XXXX | ----------------------------------------------------------------------------------- REC POS | 1 | 2-7 | 8 | 9-16 | 17-24 | 25-33 | 34-38 | 39-42 | =================================================================================== =================================================================================== FIELD | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | ----------------------------------------------------------------------------------- ELEMENT | MONTH | DAY | HOUR | RELSE | CLOUDS | OBSN | SON/BAR | SON/BAR| | | | | TIME | AND WX | TYPE | IND | NUMBER | ----------------------------------------------------------------------------------- #CHARS | XX | XX | XX | XXXX | XXXXXXXXX | XX | X | X...X | ----------------------------------------------------------------------------------- REC POS | 43-44 | 45-46 | 47-48 | 49-52 | 53-61 | 62-63 | 64 | 65-84 | =================================================================================== ======================================================================== FIELD | 17 | 18 | 19 | 20 | ------------------------------------------------------------------------ ELEMENT | SONDE | QC | DATA | TYPE OF CORRECTION | | TYPE | EFFORT| SRCE | P Z T H TD W | ------------------------------------------------------------------------ #CHARS | XXX | X | XX | XX XX XX XX XX XX | ------------------------------------------------------------------------ REC POS | 85-87 | 88 | 89-90 | 91-102 | ======================================================================== ============================= FIELD | 21 | 22 | ----------------------------- ELEMENT | # OF | NUM | |ADD RECS| LEVELS | ----------------------------- #CHARS | XXX | XXX | ----------------------------- REC POS |103-105 | 106-108 | =============================

Note: TDF63 are written as ANSI standard variable-length records/blocks, generally on magnetic tape. Immediately prior to field #1 (above) are four ASCII characters that specify the length (in bytes) of the record that follows plus the four record length descriptor bytes and must not exceed 9,992. TDF63 data written as variable-length data on disk files do not contain these record length descriptors.
TDF63 data written on magnetic tape will contain as many complete records as possible within a variable-length block of up to 12,000 bytes.

DATA PORTION (56 Characters) Repeated Number of Levels (NUM LEVELS) Times
========================================================================= FIELD | 1 | 2 | 3 | 4 | 5 | 6 | 7 | ------------------------------------------------------------------------- ELEMENT | LVL | ELPSD | | | | REL | | | QUAL | TIME | PRESS | HGT | TEMP | HUM | DPDP | ------------------------------------------------------------------------- #CHARS | X | XXXXX | XXXXXX | SXXXXXX | SXXXX | XXXX | XXX | ------------------------------------------------------------------------- REC POS | 1 | 2-6 | 7-12 | 13-19 | 20-24 | 25-28 | 29-31 | ========================================================================= ==================================================================== FIELD | 8 | 9 | 10 | 11 | 12 | -------------------------------------------------------------------- ELEMENT | WND | WND | TYP | ELEMENT QLTY | NCDC | | DIR | SPD | LVL | ET P H T U DP WD| USE | -------------------------------------------------------------------- #CHARS | XXX | XXXX | XX | XX XX XX XX XX XX XX| XX | -------------------------------------------------------------------- REC POS | 32-34 | 35-38 | 39-40 | 41-54 | 55-56 | ====================================================================

Fields 1-12 (Data Portion) may be repeated up to 175 times in each physical record.

GENERAL FORMAT NOTES

All fields must be right-justified (least-significant digit in the right-most position) unless specified otherwise.

All elements defined as numeric must be filled with leading zeros (not blanks) whenever the value stored does not require the use of all positions of the element.

Do not enter decimal points. The decimal point is implied by the position in the field.

Even though the legal range of permissible characters is presented in this manual, sometimes "illegal" characters might still be found. This convention was adopted in order that data as originally received might be preserved. Where appropriate a new value will be suggested.

IDENTIFICATION DESCRIPTIONS

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1 (BEG REC)

Begin Record Indicator -- The "#" sign will indicate the beginning of each new record.

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2-7 (WMO NUM)

WMO Number -- The WMO number is the five-digit number with a "0" appended for those stations that have a WMO Number assigned. Those stations without an assigned WMO number are assigned the five-digit number of a nearby WMO station and a digit between 5 and 9 inclusive is appended (6th position) by the Global Climate Lab., NCDC. All mobile stations will be identified by a number beginning with "99", followed by a unique four-digit number; (0010 through 0999) are reserved for semi-fixed platforms such as Ocean Station Vessels and Ice Islands).

Range of values is 000000-999999. 999999 = Number not assigned (mobile platform).

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8 (STN IND)

Station Number Indicator -- This indicator specifies the type of station number in the next field.

Range of values is 0-9.

        0 = WBAN NUMBER
        1 = AIR FORCE AUGMENTED WMO NUMBER
        2 = SHIP CALL SIGN
        3 = MOBILE PLATFORM CALL SIGN
        4 = MOBILE PLATFORM ID (Assigned by NCDC)
        5 = WMO/CARDS NUMBER
        6 = FIXED PLATFORM CALL SIGN
        7 = OTHER STATION NUMBER (ORIGIN UNKNOWN)
        8 = RESERVED
        9 = NO STATION NUMBER

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9-16 (STN NUM)

Station Number -- The number assigned to the station according to the numbering system specified in record position 8. Numbers are right justified and zero filled, ship CALL signs or mobile unit IDs are left justified and blank filled. NWS stations must enter WBAN number.

Range of values is alpha-numeric 00000000 through 99999999 and A^^^^^^^ through ZZZZZZZZ (^ = blank) in the ASCII order. If missing, enter "99999999". The only special characters allowed are blanks and dashes; all letters are uppercase.

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17-24 (LAT)

Latitude -- The station latitude in hundred-thousandths of degrees, the last character is "N" or "S" as appropriate.

Range of the numeric values is 0000000-9000000 and 99999999. When unknown, this field contains "9999999N".

Note: The conventions followed whenever latitude is exactly 0ų or 90ų are listed in
Appendix A.

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25-33 (LONG)

Longitude -- The station longitude in hundred-thousandths of degrees, the last character is "E" or "W" as appropriate.

Range of the numeric values is 00000000-18000000 and 99999999. When unknown, this field contains "99999999E".

Note: The conventions followed whenever longitude is exactly 0ų or 180ų are listed in Appendix A.

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34-38 (ELEV)

Elevation -- The height of the launch site in tenths of meters (MSL). Left most character is '-' if below mean sea level.

Range of values is all numeric values between -9999 and 99999. Missing is indicated by "99999".

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39-42 (YEAR)

Year -- The 4-digit year expressed at the hour of observation (UTC).

Range of values is the earliest year of upper air observations through the current year processed.

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43-44 (MONTH)

Month -- The numeric month expressed at the hour of observation (UTC).

Range of values is 01-12.

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45-46 (DAY)

Day -- The numeric day expressed at the hour of observation (UTC).

Range of values is 01-31.

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47-48 (HOUR)

Hour -- The hour (24-hour clock) of observation (UTC). The hour of observation will be the nearest whole hour to the time of release, H-30 to H+29 minutes.

Range of values is 00-23 and 99. Missing is indicated by "99".

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49-52 (RELSE TIME)

Time of Actual Release -- The hour and minute UTC (24-hour clock) of the actual release time expressed as HHMM where HH = hour and MM = minutes.

Range of values is 0000-2359 and 9999. Missing is indicated by "9999".

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53-61 (CLOUDS AND WX)

Clouds and Weather -- The observation of the clouds and weather at the time of release. A "-" in any of the five left-most positions is the only non-numeric value allowed.

Range of values is -----0000 through 999999999. Missing is indicated by "999999999".

The field is of the form NhCLhCMCHWWWW, where:

        Nh = The amount of low or mid-level clouds present according to 
             WMO Code Table 2700.
                0 = 0 okta (tenths)
                1 = 1 okta (1/10) or less, but not zero
                2 = 2 oktas (2/10-3/10)
                3 = 3 oktas (4/10)
                4 = 4 oktas (5/10)
                5 = 5 oktas (6/10)
                6 = 6 oktas (7/10-8/10)
                7 = 7 oktas (9/10) or more, but not overcast
                8 = 8 oktas (10/10)
                9 = Sky is obscured by fog and/or other meteorological 
                    phenomena
                - = Cloud cover is indiscernible for reason other than "9"
                    or observation not made.  
                    Code figure "/" has been converted to "-".

        CL,CM,CH = The cloud type according to WMO Code Tables 0509, 0513, 
                   and 0515.  
                   Code figure "/" has been converted to "-".

        h = WMO Code Table 1600 for the height above ground for the base 
            of the lowest cloud seen.  
            Code figure "/" has been converted to "-".

        WW = Present weather according to WMO Code Table 4677. Up to two 
             types of present weather or observations may be indicated.

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62-63 (OBSN TYPE)

Type of Observation -- Describes the type of observation.

Range of values is 00-99. Missing is indicated by "99".

        01 = radio/rawinsonde
        02 = rocketsonde
        03 = satellite
        04 = dropsonde
        05 = aircraft flight level report
        06 = Profiler
        07 = PIBAL
        08 = APOB
        09 = RAWIN (RADAR winds only)
        10 = Rawinsonde (RADAR winds)
        11 = Radiosonde (optical theodolite)
        12 = Rawinsonde (OMEGA NAVAID)
        13-98 = reserved
        99 = missing

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64 (SON/BAR IND)

Sonde/Baroswitch Number Indicator -- An indicator specifying the type of number in the next field.

Range of values is 0-9. Missing is indicated by "9".

        0 = SONDE SERIAL NUMBER
        1 = BAROSWITCH NUMBER
        2-8 reserved
        9 = missing

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65-84 (SON/BAR NUMBER)

Sonde/Baroswitch Number -- The Sonde serial number or the Baroswitch number right justified in the field.

The values of this element are alpha-numeric and may contain any combination of uppercase letters, "-", "/", ".", and numbers 0-9. Missing is indicated by 999.

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85-87 (SONDE TYPE)

Sonde Type -- The type of Sonde used at the station.

Range of values is 000-999. Missing is indicated by "999".
For a complete listing of sonde types, see Appendix C.

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88 (QC EFFORT)

Quality Control Effort -- Intended for use in conjunction with the DATA SRCE element for determining if the appendices of this documentation must be referenced for decoding the ELEMENT QUALITY flags.

Range of values is 0-9. Unknown is indicated by "9".

        0 = NCDC QC after 12/92
            See Appendix B.1 (CARDS) or Appendix 02  (NCDC).
        1 = NCDC QC prior to 1/93
            See applicable data source Appendix.
        2 = QC at source
            See Appendix B.
        3 = Complex Quality Control (CARDS/CQC) 
        4-6 = reserved
        7 = totally erroneous observation
        8 = no QC/duplicate sounding
        9 = unknown

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89-90 (DATA SRCE)

Data Source/Format -- This field indicates the data source. See appendices keyed to the data source values for details concerning the original source.

Range of values is 00-99. Unknown is indicated by "99".

        00 = TD6103 (NMC)
        01 = TD6201 (U. S. National data set prior to 1/93)
        02 = Standard Nonreal-Time Data Transfer Format (Mostly    
              MicroART - post 12/92)
        03 = Mini Rawin System Format (MRS)
        04 = TDAT/WDAT Format
        05 = RIA
        06 = Manuscript
        07 = Range standard
        08 = MIT
        09 = NCAR
        10 = TDF54
        11 = TDF56
        12 = other PC-based, semi-automated reduction system
        13 = reserved 
        14 = Russian GTS 
        15 = Peoples' Republic of China (PRC)
        16 = Argentina
        17 = British Antarctica
        18 = Hong Kong
        19 = Korea
        20 = Hungary
        21 = Netherlands
        22 = Australian GTS
        23 = Australian National
        24 = Brazil
        25 = USSR National
        26 = TD5683 (from TD5801 - NCDC)
        27 = Forecast Systems Lab/NOAA
        28 = NCDC Card Deck (CD542/544/545/645)
        29-49 = reserved
        50 = NWS Gateway
        51-98 = reserved
        99 = unknown

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91-102 (TYPE OF CORRECTION)

Type of Correction -- The type of correction applied to individual data elements by automated systems or observers. Currently, corrections which may applied to the data are not being transferred with the data.

Range of values is 00-99. Missing and/or unknown are indicated by "99".

91-92 (TYPE OF CORRECTION-P)

Pressure Corrections -- Type of correction applied to the pressure values.

        00 = No correction applied
        01 = NASA temperature correction
        02 = ECMWF temperature correction
        .
        .
        99 = Missing / unknown

93-94 (TYPE OF CORRECTION-Z)

Height Corrections -- Type of correction applied to the height values.

        00 = No correction applied
        01 = Local gravity correction
        02 = Standard gravity correction
        .
        .
        99 = Missing / unknown

95-96 (TYPE OF CORRECTION-T)

Temperature Corrections -- Type of correction applied to the temperature values.

        00 = No correction applied
        01 = NASA radiation correction
        02 = ECMWF radiation correction
        03 = NMC radiation correction
        04 = Viasala RSN-93 Solar & Infrared Radiation Correction
        .
        .
        09 = Data source indicates radiation correction applied, 
        but method and value were not described.
        .
        . 
        .
        11 = NASA lag correction
        12 = EMCWF lag correction
        13 = NMC lag correction
        .   
        .
        .
        21 = NASA radiation and lag correction
        22 = EMCWF radiation and lag correction
        23 = NMC radiation and lag correction
        .
        .
        99 = Missing / unknown

97-98 (TYPE OF CORRECTION-H)

Humidity Corrections -- Type of correction applied to the humidity values.

        00 = No corrections applied
        01 = NASA lag correction
        02 = EMCWF lag correction
        03 = NMC lag correction
        .
        .
        99 = Missing / unknown

99-100 (TYPE OF CORRECTION-TD)

Dew Point Corrections -- Type of correction applied to the dewpoint values.

        00 = No corrections applied
        01 = NASA lag correction
        02 = EMCWF lag correction
        03 = NMC lag correction
        .
        .
        99 = Missing / unknown

101-102 (TYPE OF CORRECTION-W )

Wind Corrections -- Type of correction applied to the wind values.

        00 = No corrections applied
        01 = Elevation angle correction
        02 = Ranging correction
        .
        .
        99 = Missing / unknown

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103-105 (# OF ADD RECS)

Number of Additional Records -- Number of additional records remaining in this observation. If an observation contains 175 or less levels, the additional record number will be 000. If an observation contains more than 175 levels, the first record will indicate how many records to follow. This additional record number will decrease by 1 until the last record's additional record number will be 000.

Range of values is 000-999.

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106-108 (NUM LEVELS)

Number of Levels -- This is the number of data levels found in the current physical record. The range of values is 001-175. The maximum number of levels per physical record is 175. High-vertical-resolution observations may consist of more than one physical record.

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DATA DESCRIPTIONS

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1 (LVL QUAL)

Level Quality Indicator -- Denotes the results of any quality controls applied to this level.

Range of values is 0-9.

        0 = All available elements are correct
        1 = One or more elements are suspect; no replacement level exists
        2 = One or more elements are erroneous; a replacement level exists
        3 = Operator (observer) deleted, no replacement level follows
        4 = NCDC edit/quality control has determined this level to be 
            highly suspect
        5-6 = Reserved
        7 = Unknown
        8 = Replacement level
        9 = The level has not been checked

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2-6 (ELPSD TIME)

Elasped Time -- The elapsed time since the release of the sonde in whole minutes and seconds (mmmss). Missing is indicated by "99999".

Range of values is 00000-99999; range of seconds (ss) is 00-59 except 99 when missing.

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7-12 (PRESS)

Pressure -- Atmospheric pressure at the current level in hundredths of hectopascals (0.01 millibars).

Range of values is 000000-999999. Missing is indicated by "999999".

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13-19 (HGT)

Height -- Geopotential height of the current level in whole geopotential meters (MSL); below mean sea level heights are expressed as a negative number. Each entry of height contains a "+" or "-" sign in the left-most position. The height is right-justified. When applicable, zeros are placed between the sign and first digit of the height, eg., +031137 = 31137 meters, -000127 = 127 meters below mean sea level.

Range is all numeric values between -999999 and +999999. Missing is indicated by "-999999".

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20-24 (TEMP)

Temperature -- The air temperature at the current level in degrees and tenths Celsius. Each entry of temperature contains a leading "+" or "-" sign in the left-most position. The temperature is right- justified. When applicable, zeros are placed between the sign and the first digit of the temperature, e.g., +0012 = 1.2ųC, -0697 = -69.7ųC.

Range is all numeric values between -9999 and +9999. Missing is indicated by "+9999".

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25-28 (REL HUM)

Relative Humidity -- The relative humidity at the current level to 0.1 percent.

Range of values is 0000-9999. Missing is indicated by "9999".

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29-31 (DPDP)

Dew-Point Depression -- The dew-point depression at the current level in degrees and tenths Celsius.

Range of values is 000-999. Missing is indicated by "999".

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32-34 (WND DIR)

Wind Direction -- Direction of the wind at the current level in whole degrees (nearest five degrees for observations received through GTS).

Range of values is 000-360, 399, and 999. Missing is indicated by "999". (Direction when wind is calm is 000; when direction is variable 399 is entered.)

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35-38 (WND SPD)

Wind Speed -- Speed of the wind in meters per second and tenths.

Range of values is 0000-9999. Missing is indicated by "9999".

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39-40 (TYP LVL)

Type of Level -- The code indicating the reason for selection of the level. Codes 51-99 are used for those levels that satisfy the criteria for multiple types.

Range of values is 00-99.

        00 = Operator deleted level
        01 = Operator added level
        02 = Aircraft report
        03 = Dropsonde
        04 = Rocketsonde
        05 = Profiler
        06-08 = reserved
        09 = Begin missing data (all elements)
        10 = End missing data (all elements)
        11 = Begin missing temperature data/doubtful altitude
        12 = End missing temperature data
        13 = Begin missing relative humidity/dew-point         
             depression data
        14 = End missing relative humidity/dew-point depression data
        15 = Begin doubtful altitude data
        16 = Begin doubtful temperature, altitude data
        17 = End doubtful temperature data
        18-19 = reserved
        20 = Interpolated (generated) mandatory pressure level
        21 = Interpolated (generated) level other than a mandatory 
             pressure level
        22 = Highest level reached before balloon descent because of 
             icing or turbulence
        23 = Balloon re-ascended beyond previous highest level
        24 = Base pressure for stability index
        25 = Zero-degree crossing for the RADAT message
        26 = Tropopause
        27 = Maximum wind level
        28 = Below surface level
        29-30 = reserved
        31 = Surface level
        32 = Mandatory pressure level
        33 = Within 20 hectopascals (mb.) of the surface
        34 = Flight termination level
        35 = Relative humidity level selection terminated
        36 = Pressure less than 10 hectopascals
        37 = Mandatory temperature level
        38 = Significant temperature level
        39 = Significant relative humidity level
        40 = Winds at constant height (above ground level)
        41 = Mandatory wind level
        42 = Significant wind level
        43 = Incremental wind level (e.g., 1-minute, fixed regional)
        44 = Significant thermodynamic level (reason for       
                    selection is unknown)
        45 = High resolution data sample
        46 = Other/unspecified
        47 = Generated winds at incremental heights
        48-58 = reserved
        59 = Begin missing data (all elements) at a tropopause level
        60 = End missing data (all elements) at a tropopause level
        61 = Begin missing temperature data at a tropopause level
        62 = End missing temperature data at a tropopause level
        63 = Begin missing relative humidity/dew-point depression data at a 
             tropopause level
        64 = End missing relative humidity/dew-point depression data at a 
             tropopause level
        65 = Begin doubtful altitude data at a tropopause level
        66 = Begin doubtful temperature, altitude data at a tropopause level
        67 = End doubtful temperature data at a tropopause level
        68 = reserved
        69 = Begin missing data (all elements) at a mandatory pressure level
        70 = End missing data (all elements) at a mandatory pressure level
        71 = Begin missing temperature data at a mandatory pressure level
        72 = End missing temperature data at a mandatory pressure level
        73 = Begin missing relative humidity/dew-point depression data at a
             mandatory pressure level
        74 = End missing relative humidity/dew-point depression data at a 
             mandatory pressure level
        75 = Begin doubtful altitude data at a mandatory pressure level
        76 = Begin doubtful temperature, altitude data at a mandatory 
             pressure level
        77 = End doubtful temperature data at a mandatory pressure level
        78-80 = reserved
        81 = Level satisfies requirements for selection as a mandatory 
             pressure level and as a tropopause level
        82 = Level satisfies requirements for selection as a mandatory 
             pressure level and as a significant level
        83 = Level satisfies requirements for selection as a mandatory 
             pressure level and as the surface level
        84 = Highest level reached before balloon descent because of icing 
             or turbulence and is a mandatory level
        85 = Balloon reascended beyond previous highest level and is a 
             mandatory level
        86 = Base pressure for stability index and is a mandatory level
        87 = Zero-degree crossing for RADAT message and is a mandatory level
        88 = Maximum wind level and is a mandatory level
        89 = Tropopause level, maximum wind level, and mandatory level
        90 = Tropopause level and is a maximum wind level
        91-99 = reserved

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41-54 (ELEMENT QLTY)

Element Quality Flags -- These fields contain the result of any quality control procedures for identifying suspect and doubtful individual elements, and elements that failed QC checks Descriptions of the element quality flags are contained in the appendices which are keyed to the DATA SRCE field. If, for example, the DATA SRCE is 01 (source = TD6201), the appendix containing the element quality flag descriptions is Appendix 01; if DATA SRCE is 02 the associated appendix is numbered 02, etc. The Element Quality is assigned a value equivalent to the least correct flag.

The range of values is listed in each applicable appendix. Although the range of values for element quality flags are specific for each data source, as a general rule, any combination of ASCII characters except lowercase letters and "#" is allowed in this element.

Flags set as a result of the Complex Quality Control process, QC EFFORT TYPE 3, are described in Appendix B.

41-42 (ELEMENT QLTY-ET): Elasped Time Quality -- Element quality for elasped time value.
43-44 (ELEMENT QLTY-P): Pressure/Ranging Quality -- Element quality for pressure/ranging value.
45-46 (ELEMENT QLTY-H): Height Quality -- Element quality for height value.
47-48 (ELEMENT QLTY-T): Temperature Quality -- Element quality for temperature value.
49-50 (ELEMENT QLTY-U): Humidity Quality -- Element quality for humidity value.
51-52 (ELEMENT QLTY-DP): Dew-Point Depression Quality -- Element quality for dew-point depression value.
53-54 (ELEMENT QLTY-WD): Wind Direction/Speed Quality -- Element quality for wind direction and speed values.

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55-56 (NCDC USE)

NCDC Use -- Reserved for internal NCDC use

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