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Transmitted Dropwindsonde Observations in HRD Spline Analysis (HSA) Format

[ Explanation of HSA Format | Example ]

HRD has established a standardized ASCII format for observations used as input to the nested HRD Spline Analysis* and several other numerical/graphics routines. Each line in an HSA file contains the meteorological observations for a specified data source at a nominal date, time, geographical position, and pressure level. Records in HSA format are created for all mandatory, significant, additional, tropopause, and maximum wind levels reported in the dropsonde transmitted messages during a mission. The data are decoded from TEMP DROP format.

* For details about the nested HRD Spline Analysis, please consult:
  • Franklin, J. L., S. E. Feuer, J. Kaplan, and S. D. Aberson, 1996: Tropical cyclone motion and surrounding flow relationships: Searching for Beta-gyres in Omega dropwindsonde datasets. Mon. Wea. Rev., 124, 64-84.
  • Franklin, J. L., S. J. Lord, S. E. Feuer, and F. D. Marks, Jr., 1993: The kinematic structure of Hurricane Gloria (1985) determined from nested analyses of dropwindsonde and doppler radar data. Mon. Wea. Rev., 121, 2433-2451.

  • EXPLANATION OF HSA FORMAT

    Each ASCII record in an HSA file has a length of 78 characters. The standard format is:

    II DDDDDD. HHHH XXX.XXXYYYY.YYY PPPP.P TTTT.T RRRR.R ZZZZZ.Z UUUU.U VVVV.V FFFF
    FieldValue**
    Description
    II2 Digit IntegerHSA Data Source Index (this is set to 1 for dropwindsondes)
    DDDDDD.7 Digit Real Date of Observation in yymmdd, in which yy is the last two digits of the year, MM is the month, and DD is the day of the month
    HHHH4 Digit Integer Time of Observation in hhmm, in which hh is the hour (UTC) and mm is the minutes
    XXX.XXX7 Digit Real Latitude of Observation (°N positive)
    YYYY.YYY8 Digit Real Longitude of Observation (°W positive)
    PPPP.P6 Digit Real Pressure Level of Observation (mb or hPa) -- 1070.0 indicates the surface (see ZZZZZ.Z for actual pressure value)
    TTTT.T6 Digit Real Temperature (°C)***
    RRRR.R6 Digit Real Relative Humidity (%)***
    ZZZZZ.Z7 Digit Real Geopotential Height (m)*** -- this is surface pressure (mb) if PPPP.P = 1070.0
    UUUU.U6 Digit Real U (Zonal) Wind Component (m s-1)***
    VVVV.V6 Digit Real V (Meridional) Wind Component (m s-1)***
    FFFF4 Character Data Flags (these indicate level type for operational dropwindsonde data):
    MANL - mandatory
    SIGL - significant
    ADDL - additional (extrapolated)
    TROP - tropopause
    MAXW - maximum wind
    **Decimal Points are included in the number of Real variable digits.
    *** Missing values of T, RH, Z, U, and V are assigned -99.0.
    To read a record from an HSA file in a FORTRAN program, use the following variable masks for the fields in the Format statement:

    I2,X,F7.0,X,I4,X,F7.3,F8.3,X,3(F6.1,X),F7.1,2(F6.1,X),A4


    EXAMPLE

    The following example shows how an operational dropsonde transmitted message is decoded into HSA format. The message contains the actual sounding observations of a sonde released from the NOAA G-IV aircraft during a Hurricane Floyd synoptic surveillance mission on 13 September 1999.

    Original Encoded Message Format

    Sonde # 990838036  1843 UTC  13 Sep 99
    UZNT13 KWBC 131915
    
    XXAA  63192 99280 70740 08084 99007 278// 05535 00060 27445 05537 
    92745 21604 07543 85477 18248 09048 70122 10042 07543 50584 05156 
    07549 40756 15533 08543 30967 29549 07025 25095 38750 10524 20244 
    511// 13531 88999 77999                                           
    
    51515 10167 02018                                                 
    61616 NOAA9 1708A FLOYD OB 04                                     
    62626 SPL 2799N07416W MBL WND 06037=
    
    XXBB  63198 99280 70740 08084 00007 278// 11005 27845 22958 23608 
    33935 22002 44779 15657 55649 05635 66642 05227 77634 04857 88616 
    03429 99609 03456 11571 00658 22546 01731 33510 04156 44478 07739 
    55443 10757 66414 14531 77380 18127 88332 24533 99255 37549 11224 
    44959 22199 513// 33179 58109                                     
    
    21212 00007 05535 11918 07542 22892 09052 33672 07539 44511 07548 
    55449 09047 66289 06524 77238 12018 88195 14031 99179 12552       
    
    31313 09608 81843                                                 
    51515 10167 02018                                                 
    61616 NOAA9 1708A FLOYD OB 04                                     
    62626 SPL 2799N07416W MBL WND 06037=                              
    

    Decoded HSA Format

     1 990913. 1843  27.990  74.160 1070.0   27.8  -99.0  1007.0 -14.7  -10.3 MANL  
     1 990913. 1843  27.990  74.160 1000.0   27.4   75.3    60.0 -15.6  -10.9 MANL  
     1 990913. 1843  27.990  74.160  925.0   21.6   97.5   745.0 -21.4   -5.7 MANL  
     1 990913. 1843  27.990  74.160  850.0   18.2   72.7  1477.0 -24.7     .0 MANL  
     1 990913. 1843  27.990  74.160  700.0   10.0   74.6  3122.0 -21.4   -5.7 MANL  
     1 990913. 1843  27.990  74.160  500.0   -5.1   62.8  5840.0 -24.3   -6.5 MANL  
     1 990913. 1843  27.990  74.160  400.0  -15.5   76.0  7560.0 -22.0   -1.9 MANL  
     1 990913. 1843  27.990  74.160  300.0  -29.5   63.3  9670.0 -12.1   -4.4 MANL  
     1 990913. 1843  27.990  74.160  250.0  -38.7   60.4 10950.0 -11.9    3.2 MANL  
     1 990913. 1843  27.990  74.160  200.0  -51.1  -99.0 12440.0 -11.3   11.3 MANL  
    
     1 990913. 1843  27.990  74.160 1007.0   27.8  -99.0   -99.0 -99.0  -99.0 SIGL  
     1 990913. 1843  27.990  74.160 1005.0   27.8   75.4   -99.0 -99.0  -99.0 SIGL  
     1 990913. 1843  27.990  74.160  958.0   23.6   95.0   -99.0 -99.0  -99.0 SIGL  
     1 990913. 1843  27.990  74.160  935.0   22.0   98.7   -99.0 -99.0  -99.0 SIGL  
     1 990913. 1843  27.990  74.160  779.0   15.6   62.2   -99.0 -99.0  -99.0 SIGL  
     1 990913. 1843  27.990  74.160  649.0    5.6   77.9   -99.0 -99.0  -99.0 SIGL  
     1 990913. 1843  27.990  74.160  642.0    5.2   82.4   -99.0 -99.0  -99.0 SIGL  
     1 990913. 1843  27.990  74.160  634.0    4.8   60.1   -99.0 -99.0  -99.0 SIGL  
     1 990913. 1843  27.990  74.160  616.0    3.4   81.1   -99.0 -99.0  -99.0 SIGL  
     1 990913. 1843  27.990  74.160  609.0    3.4   64.5   -99.0 -99.0  -99.0 SIGL  
     1 990913. 1843  27.990  74.160  571.0     .6   54.8   -99.0 -99.0  -99.0 SIGL  
     1 990913. 1843  27.990  74.160  546.0   -1.7   79.2   -99.0 -99.0  -99.0 SIGL  
     1 990913. 1843  27.990  74.160  510.0   -4.1   63.0   -99.0 -99.0  -99.0 SIGL  
     1 990913. 1843  27.990  74.160  478.0   -7.7   73.6   -99.0 -99.0  -99.0 SIGL  
     1 990913. 1843  27.990  74.160  443.0  -10.7   56.6   -99.0 -99.0  -99.0 SIGL  
     1 990913. 1843  27.990  74.160  414.0  -14.5   77.5   -99.0 -99.0  -99.0 SIGL  
     1 990913. 1843  27.990  74.160  380.0  -18.1   79.6   -99.0 -99.0  -99.0 SIGL  
     1 990913. 1843  27.990  74.160  332.0  -24.5   74.5   -99.0 -99.0  -99.0 SIGL  
     1 990913. 1843  27.990  74.160  255.0  -37.5   61.3   -99.0 -99.0  -99.0 SIGL  
     1 990913. 1843  27.990  74.160  224.0  -44.9   37.7   -99.0 -99.0  -99.0 SIGL  
     1 990913. 1843  27.990  74.160  199.0  -51.3  -99.0   -99.0 -99.0  -99.0 SIGL  
     1 990913. 1843  27.990  74.160  179.0  -58.1   90.0   -99.0 -99.0  -99.0 SIGL  
    
     1 990913. 1843  27.990  74.160  918.0  -99.0  -99.0   -99.0 -20.9   -5.6 SIGL  
     1 990913. 1843  27.990  74.160  892.0  -99.0  -99.0   -99.0 -26.8     .0 SIGL  
     1 990913. 1843  27.990  74.160  672.0  -99.0  -99.0   -99.0 -19.4   -5.2 SIGL  
     1 990913. 1843  27.990  74.160  511.0  -99.0  -99.0   -99.0 -23.9   -6.4 SIGL  
     1 990913. 1843  27.990  74.160  449.0  -99.0  -99.0   -99.0 -24.2     .0 SIGL  
     1 990913. 1843  27.990  74.160  289.0  -99.0  -99.0   -99.0 -11.2   -5.2 SIGL  
     1 990913. 1843  27.990  74.160  238.0  -99.0  -99.0   -99.0  -8.0    4.6 SIGL  
     1 990913. 1843  27.990  74.160  195.0  -99.0  -99.0   -99.0 -10.3   12.2 SIGL  
     1 990913. 1843  27.990  74.160  179.0  -99.0  -99.0   -99.0 -21.9   15.3 SIGL  
    

    KEY:
       
    Mandatory Level Observations  
       
    Signficant T & RH Level Observations  
       
    Signficant Wind Level Observations  


    NOTES ABOUT DECODING

    1. The obervational date and time of the HSA records are those from when the sonde was launched. The day of the month is extracted from the second group of Section 1 of TEMP DROP code Parts A and B in the transmitted message. The launch time is retreived from the third group of Section 7 of TEMP DROP code Part B. If no Section 7 line is present, the time to the nearest hour is assigned instead to the HSA records. The hour is also extracted from the second group of Section 1 of TEMP DROP code Parts A and B. The month and year match those in the special HRD header line at the top of the dropsonde transmitted message.

    2. The geographical position in the HSA records is the location where the sonde splashed. This information is retrieved from the "SPL" remarks in the "62626" lines that appear in Section 10 of TEMP DROP code Parts A and B in the transmitted message. If no SPL group appears in the message, the launch position is instead assigned to the HSA records. This information is extracted from the third and fourth groups of Section 1 of TEMP DROP code Parts A and B in the transmitted message.

    3. If additional level observations are present, only those containing extrapolated altitude data are decoded into HSA records. These are retrieved from the group following a "10190" indicator in Section 9 of TEMP DROP code Part B.

    4. The observations in the transmitted message are converted into HSA format sequentially. Mandatory level observations in Sections 1-4 of Part A of the TEMP DROP code in the transmitted message are decoded first, followed by the tropopause level observations (if present) in Section 3 of Part A, maximum wind level observations (if present) in Section 4 of Part A, signficant temperature and relative humidity level observations in Section 5 of Part B, signficant wind level observations in Section 6 of Part B, and finally additional level observations (if present) in Section 9 of Part B.


    Please contact Sim Aberson if you have any questions about HSA format.

    Last modified: 14 March 2000.
    Please report any problems to the HRD webmaster.

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