BAMEX Soundings Dropsonde WMI Learjet Profiles Data [JOSS]

	1.0 General Description

		This is one of the upper air data sets developed for the
	Bow Echo and Mesoscale Convection Vortex Experiment (BAMEX). 
	This data set contains 438 soundings launched between 5/24/2003 
	and 7/06/2003, during 18 missions, from the Weather Modification Inc. 
	(WMI) Learjet 35. The dropsonde data was provided by the National 
	Center for Atmospheric Research Atmospheric Technology Divison 

	For more information on the NCAR GPS Dropsonde System please visit 
	the following site:  
	NCAR GPS Dropsonde System 
	1.1 ATD Contacts and Mailing Address

	Contacts:               Terry Hock

			        Junhong Wang
			        Kate Beierle

	Mailing Address:        NCAR/Atmospheric Technology Division
				P.O. Box 3000
				1850 Table Mesa Drive
		    	    	Boulder, CO 80307; USA

	2.0  Detailed Data Description

	2.1  Detailed Format Description
          All upper air soundings were converted to University Corporation
     for Atmospheric Research/Joint Office for Science Support (UCAR/JOSS)
     Cross Chain LORAN Atmospheric Sounding System (CLASS) Format
     (JCF).  JCF is a version of the National Center for Atmospheric Research
     (NCAR) CLASS format and is an ASCII format consisting of 15 header
     records for each sounding followed by the data records with associated QC
     Header Records
          The header records (15 total records) contain data type, project ID,
     site ID, site location, release time, sonde type, meteorological and wind
     data processors, and the operator's name and comments.  The first five
     header lines contain information identifying the sounding, and have a
     rigidly defined form.  The following 7 header lines are used for auxiliary
     information and comments about the sounding, and may vary from dataset
     to dataset.  The last 3 header records contain header information for the
     data columns.  Line 13 holds the field names, line 14 the field units, and
     line 15 contains dashes ('-' characters) delineating the extent of the 
          The five standard header lines are as follows:
          Line  Label (padded to 35 char)              Contents
            1   Data Type:                        Description of type and
                                                    resolution of data.
            2   Project ID:                       ID of weather project.
            3   Release Site Type/Site ID:        Description of launch site.
            4   Release Location (lon,lat,alt):   Position of launch site,
                                                    in format described below.
            5   UTC Release Time (y,m,d,h,m,s):   Time of release, in format:
                                                    yyyy, mm, dd, hh:mm:ss

          The release location is given as:  lon (deg min), lat (deg min), lon
     (dec. deg), lat (dec. deg), alt (m)
          Longitude in deg min is in the format:  ddd'W where ddd
     is the number of degrees from True North (with leading zeros if
     necessary), is the decimal number of minutes, and W represents
     W or E for west or east longitude, respectively. Latitude has the same
     format as longitude, except there are only two digits for degrees and N or
     S for north/south latitude. The decimal equivalent of longitude and 
     latitude and station elevation follow.
          The seven non-standard header lines may contain any label and
     contents.  The label is padded to 35 characters to match the standard
     header lines. 

          Line  Label (padded to 35 char)              Contents

            6   Sonde Type/ID/Sensor ID/Tx Freq:  Vaisala RD93 GPS Dropsonde Serial Number 
	                                          YYWWDSSSS, where YY last two digits 
                                                  of year, WW - week number (1-52),
						  D - day of the week (1-7,Monday=1), and
						  SSSS is the sequence number

            7   System Operator/Comments:	  Comments recorded by operator during
	                                          flight. This line is often blank.          

	    8   Input File:                       Original file from ATD.
     Data Records
          The data records each contain time from release, pressure,
     temperature, dew point, relative humidity, U and V wind components, wind
     speed and direction, ascent rate, balloon position data, altitude, and 
     quality control flags (see the QC code description).  Each data line 
     contains 21 fields, separated by spaces, with a total width of 130 
     characters.  The data are right-justified within the fields.  All fields
     have one decimal place of precision, with the exception of latitude and
     longitude, which have three decimal places of precision.  The contents
     and sizes of the 21 fields that appear in each data record are as follows:
     Field     Format
     No.   Width          Parameter               Units               Missing 
       1     6  F6.1  Time                        Seconds             9999.0
       2     6  F6.1  Pressure                    Millibars           9999.0
       3     5  F5.1  Dry-bulb Temperature        Degrees C            999.0
       4     5  F5.1  Dew Point Temperature       Degrees C            999.0
       5     5  F5.1  Relative Humidity           Percent              999.0
       6     6  F6.1  U Wind Component            Meters / Second     9999.0
       7     6  F6.1  V Wind Component            Meters / Second     9999.0
       8     5  F5.1  Wind Speed                  Meters / Second      999.0
       9     5  F5.1  Wind Direction              Degrees              999.0
      10     5  F5.1  Ascension Rate              Meters / Second      999.0
      11     8  F8.3  Longitude                   Degrees             9999.0
      12     7  F7.3  Latitude                    Degrees              999.0
      13     5  F5.1  Range                       Kilometers           999.0
      14     5  F5.1  Azimuth                     Degrees              999.0
      15     7  F7.1  Altitude                    Meters             99999.0
      16     4  F4.1  QC for Pressure             Code (see below)      99.0
      17     4  F4.1  QC for Temperature          Code (see below)      99.0
      18     4  F4.1  QC for Humidity             Code (see below)      99.0
      19     4  F4.1  QC for U Component          Code (see below)      99.0
      20     4  F4.1  QC for V Component          Code (see below)      99.0
      21     4  F4.1  QC for Ascension Rate       Code (see below)      99.0
          Fields 16 through 21 contain the Quality Control information
     derived at the UCAR Joint Office for Science Support (UCAR/JOSS). 
     Any QC information from the original sounding is replaced by the
     following JOSS codes:
     Code      Description
     99.0  Unchecked (QC information is "missing.")  ("UNCHECKED")
     1.0   Checked, datum seems physically reasonable.  ("GOOD")
     2.0   Checked, datum seems questionable on physical basis.("MAYBE")
     3.0   Checked, datum seems to be in error.  ("BAD")
     4.0   Checked, datum is interpolated.  ("ESTIMATED")
     9.0   Checked, datum was missing in original file.  ("MISSING")
     Sample Data
          The following are sample records for the BAMEX Soundings
     Dropsonde WMI Learjet Profile Data in JOSS CLASS format.   
     The data portion is much longer than 80 characters and therefore wraps 
     around to a second line.  See section 2.1 for an exact format 

Data Type:                         Sounding  
Project ID:                        BAMEX 2003 Class Format Dropsonde 
Sounding from Lear
Release Site Type/Site ID:         WMI Lear 35A , N425AS              
Release Location (lon,lat,alt):    094 19.68'W, 41 50.82'N,  -94.33,  
41.85, 12861.0
UTC Release Time (y,m,d,h,m,s):    2003, 06, 10, 05:39:51
Sonde Type/ID/Sensor ID/Tx Freq:   031335040
System Operator/Comments:          ,
Input File:                        D20030610_053951QC.cls
Nominal Release Time (y,m,d,h,m,s):2003, 06, 10, 05:39:51
 Time  Press  Temp  Dewpt  RH    Uwind  Vwind  Wspd  Dir   dZ      Lon   
  Lat   Elev  Azim    Alt    Qp   Qt   Qh   Qu   Qv   Qdz
  sec    mb     C     C     %     m/s    m/s   m/s   deg   m/s     deg   
  deg    deg   deg     m    code code code code code code
------ ------ ----- ----- ----- ------ ------ ----- ----- ----- -------- 
------- ----- ----- ------- ---- ---- ---- ---- ---- ----
 702.6  968.6  16.9  15.9  94.0 9999.0 9999.0 999.0 999.0 999.0 9999.000 
999.000 999.0 999.0   217.1 99.0 99.0 99.0  9.0  9.0  9.0
 702.1  967.9  16.9  15.9  94.0 9999.0 9999.0 999.0 999.0 -11.8 9999.000 
999.000 999.0 999.0   223.0 99.0 99.0 99.0  9.0  9.0 99.0
 701.6 9999.0 999.0 999.0 999.0 9999.0 9999.0 999.0 999.0 999.0 9999.000 
999.000 999.0 999.0 99999.0  9.0  9.0  9.0  9.0  9.0  9.0
 701.1  966.7  16.9  15.9  93.8 9999.0 9999.0 999.0 999.0 999.0 9999.000 
999.000 999.0 999.0   233.5 99.0 99.0 99.0  9.0  9.0  9.0
 700.6  966.1  16.9  15.9  93.7 9999.0 9999.0 999.0 999.0 -11.2 9999.000 
999.000 999.0 999.0   239.1 99.0 99.0 99.0  9.0  9.0 99.0

	2.2. Data File Specifics from ATD 

	The files contain data calculated at half-second intervals . The 
	variable pressure, temperature, and relative humidity are 
	calibrated values from measurements made by the sonde.  The dew point 
	is calculated from the relative	humidity. The altitude value is 
	calculated from the hydrostatic equation using pressure, temperature, 
	and dew point.  For the dropsondes specifically, if the radiosonde is 
	launched over water, the height is calculated by integrating from 
	the surface (sea level) upward.  However, if the radisonde is launched 
	over land, as was the case with BAMEX, we integrate from the flight 
	level down. The rate of ascent is obtained from the altitude 
	difference between two successive time steps.  The position 
	(lat, lon), angle and range come from the GPS and altitude data. 
	All wind data are computed from GPS navigation signals received from 
	the sonde.  The	raw wind values are calculated at a one half second 
	data rate by a commercial processing card.  These raw values are 
	subjected to a digital filter to remove low frequency oscillations
	due to the sonde pendulum motion beneath the balloon. This time record 
	is used in the interpolation of the pressure, temperature, and humidity data.

	3.0 Quality Control  

	3.1 ATD Data Quality Control 

	The raw soundings are first run through the Atmospheric Sounding Processing 
	ENvironment (ASPEN), which analyzes the data, performs smoothing, and removes 
	suspect data points.  The soundings are then visually evaluated for 
	outliers, or any other obvious problems.  Histograms of pressure, temperature,
	relative humidity, wind speed and wind direction are then created to check the 
	range, and number of occurances of values and are derived from data at all 
	levels for all soundings. Finally, time series plots of temperature, relative 
	humidity, and wind speed and direction are created.  They are used to both 
	examine the consistency of soundings launched from the same flight, and to 
	show the variablity of soundings from different missions.  

	Based on the QC procedures above, a couple of small problems with some of the 
	soundings were identified and corrected: incorrect flight-level pressure data, 
	problematic temperature data near the top of the profile, and bad data at the 
	surface.  After minor corrections, the data are fine.

	3.2  JOSS Quality Control Processing
        This dataset underwent am automated QC process.  The dataset underwent
	internal consistency checks which included two types of checks,gross 
	limit checks on all parameters and rate-of-change checks on 
	temperature, pressure and ascension rate. Some further information on 
     	the QC processing conducted by JOSS can be found in Loehrer et al. 
	(1996)	and Loehrer et al. (1998).
     	3.2.1  Gross Limit Checks
        These checks were conducted on each sounding and data were 
	automatically flagged as appropriate.  Only the data point under 
	examination was flagged.  JOSS conducted the following gross limit
     	checks on the BAMEX 2003 Soundings Dropsonde WMI Learjet Profile Data.  
	In the table P = pressure, T =	temperature, RH = relative humidity, 
	U = U wind component, V = V wind component, B = bad, and 
	Q = questionable.

                                               Parameter(s)    Flag
     Parameter          Gross Limit Check        Flagged      Applied
     Pressure           < 0 mb or > 1050 mb      P               B
     Altitude           < 0 m  or > 40000 m      P, T, RH        Q
     Temperature        < -99.9C or > 45C           T            Q
     Dew Point          < -99.9C or > 30C              RH        Q 
                        > Temperature               T, RH        Q
     Relative Humidity  < 0% or > 100%                 RH        B
     Wind Speed         < 0 m/s or >  100 m/s      U, V          Q
                        > 150 m/s                  U, V          B
     U Wind Component   < 0 m/s or >  100 m/s      U             Q
                        > 150 m/s                  U             B
     V Wind Component   < 0 m/s or >  100 m/s         V          Q
                        > 150 m/s                     V          B
     Wind Direction     < 0 deg or > 360 deg       U, V          B
     Ascent Rate        < -45 m/s or > 0 m/s     P, T, RH        B

         3.2.2  Vertical Consistency Checks

	These checks were conducted on each sounding and data were
        automatically flagged as appropriate.  These checks were 
        started at the lowest level of the sounding and compared 
        neighboring values.  In the case of checks ensuring that 
        the values increased/decreased as expected, only the data 
        point under examination was flagged.  However, for the 
        other checks, all of the data points used in the 
        examination were flagged.  All items within the table are 
        as previously defined.

                        Vertical Consistency   Parameter(s)    Flag
     Parameter                 Check             Flagged      Applied
     Time               increasing/equal         None          None
     Altitude           increasing/equal         P, T, RH        Q
     Pressure           decreasing/equal         P, T, RH        Q
                        > 3 mb/s or < -3 mb/s    P, T, RH        Q
                        > 5 mb/s or < -5 mb/s    P, T, RH        B
     Temperature        < -15 C/km               P, T, RH        Q
                        < -30 C/km               P, T, RH        B
          from surface to 250 mb:
                        > 100 C/km (not applied
                                   at p < 250mb) P, T, RH        Q
                        > 200 C/km (not applied
                                   at p < 250mb) P, T, RH        B
          for pressures < 250 mb:
                        >   100 C/km (not applied
                                   at p > 150mb) P, T, RH        Q
                        >   200 C/km (not applied
                                   at p > 150mb) P, T, RH        B
     Ascent Rate        change of > 3 m/s
                               or < -3 m/s       P               Q
                        change of > 5 m/s
                               or < -5 m/s       P               B

	4.0  References
     	Loehrer, S. M., T. A. Edmands, and J. A. Moore, 1996: TOGA COARE
          upper-air sounding data archive: development and quality control
          procedures.  Bull. Amer. Meteor. Soc., 77, 2651-2671.
     	Loehrer, S. M., S. F. Williams, and J. A. Moore, 1998: Results from
          UCAR/JOSS quality control of atmospheric soundings from field
          projects.  Preprints, Tenth Symposium on Meteorological
          Observations and Instrumentation, Phoenix, AZ, Amer. Meteor.
          Soc., 1-6.