BAMEX Sounding Composite 5mb Level Upper Air Data [JOSS] 1.0 Dataset Overview This dataset is a composite of data from all BAMEX sounding platforms interpolated to a constant vertical resolution of 5 hPa. 2.0 Detailed Dataset Description The `native' resolution data for every sounding were interpolated to 5 hPa vertical reslution files. The surface data point was kept as the initial level in each sounding. The first interpolated data point was at the next lowest pressure evenly divisible by 5 and then every 5 hPa pressure level beyond that point to either 50 hPa or the lowest pressure level reached by the radiosonde, whichever came first. The first 15 lines of each file (the header information) were kept without change. For the interpolation, the software searched for two data points around the desired pressure level. The search was conducted by looking for two valid (i.e. non-missing) data points around the desired pressure level, while also paying attention to the time difference between the two data points as well as their quality control flags. There was a search for the two best possible data points to use in the interpolation. If the desired pressure level was within the original dataset, that data point was used without interpolation. There was first a search for values flagged as good within some time range (50 sec for temperature, humidity, and wind and 100 sec for pressure; hereafter termed the ARANGE) and the interpolated data point was flagged as good. Failing that, it searched for values flagged as estimated within the same time range and the interpolated data point was flagged as estimated. Then the search went for good values within a wider time range (100 sec for temperature, humidity, and wind and 200 sec for pressure; hereafter termed the BRANGE) the flag for the interpolated data point here was then degraded (even though two `good' data points were used there was a significant time difference between them) to questionable. Then, in turn, estimated values within the BRANGE were used (flag set to questionable), questionable values within the BRANGE (flag set to bad), good values greater than the BRANGE apart (flag set to bad), estimated values greater than BRANGE apart (flag set to bad), questionable values greater than BRANGE apart (flag set to bad), finally any bad values (flag set to bad). This search was conducted separately for each interpolated variable (pressure, temperature, relative humidity, and the u and v wind components. Thus for each interpolated data point, the quality control flag was set to the worst case among the data points used in the interpolation, except, for each time range apart, the quality control flag was degraded one level (i.e. good to questionable, etc). The quality control flags should be carefully heeded in these files. While some of the data may look good, it may have been interpolated over large pressure intervals, and thus be suspect. For each interpolated data point the dew point was calculated from the temperature and relative humidity (Bolton 1980) and the total wind speed and direction were calculated from the interpolated u and v component values. Also, the altitude and time were interpolated using the same data points used for the pressure interpolation. The ascension rate was recalculated based on the time and altitude values from the two data points used to interpolate the 5 hPa data point. Thus the ascension rate values do not reflect the values based on the interpolated data. The latitude and longitude values were interpolated using the same data points used in the wind component interpolation. 3.0 JOSS CLASS Format (ASCII text) Description 3.1 Header records The header records (15 total records) contain data type, project ID, site ID, site location, actual release time, nominal release time, and possibly other specialized information. The first five header lines contain information identifying the sounding, and have a rigidly defined form. The following 6 header lines are used for auxiliary information and comments about the sounding, and they vary significantly from data set to data set. The next line (line 12) contains the Nominal date and time of the release. 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 field. The six standard header lines are as follows: Line Label (fixed to 35 char in length) 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 release site. 4 Release Location (lon,lat,alt): Position of release site, in format described below. 5 UTC Release Time: Time of release, in format: yyyy, mm, dd, hh:mm:ss 12 UTC Nominal Release Time: Nominal release time. The release site type/site ID typically consists of the site name, but may also contain a three or four letter site ID. 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 mm.mm'W where ddd is the number of degrees from True North (with leading zeros if necessary), mm.mm 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. 3.2 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 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 Missing No. Width Parameter Units Value ---------------------------------------------------------------------- 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 Variable (see below) 999.0 14 5 F5.1 Variable (see below) 999.0 15 7 F7.1 Altitude Meters 99999.0 16 4 F4.1 QC flag for Pressure Code (see below) 99.0 17 4 F4.1 QC flag for Temperature Code (see below) 99.0 18 4 F4.1 QC flag for Humidity Code (see below) 99.0 19 4 F4.1 QC flag for U Component Code (see below) 99.0 20 4 F4.1 QC flag for V Component Code (see below) 99.0 21 4 F4.1 QC flag for Ascension Rate Code (see below) 99.0 ---------------------------------------------------------------------- Fields 13 and 14 are `variable' because depending on the sounding system the variables used in these positions can vary. Fields 16 through 21 contain the Quality Control information (flags) generated locally at JOSS. These flags are based on the automated or visual checks made. The JOSS QC flags are as follows: 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') ---------------------------------------------------------------------- 3.3 Sample data The following is a sample portion of a JOSS CLASS format file including header records. The data portion is much longer than 80 characters and, therefore, wraps around to a second line. Data Type: NWS Project ID: BAMEX Comp 5mb Snding Release Site Type/Site ID: LCH Lake Charles, LA Release Location (lon,lat,alt): 093 12.00'W, 30 6.00'N, -93.20, 30.10, 5.0 UTC Release Time (y,m,d,h,m,s): 2003, 05, 27, 23:00:00 Ascension No: 1294 Radiosonde Serial Number: 241505011 Radiosonde Manufacturer: Vaisala / / / Nominal Release Time (y,m,d,h,m,s):2003, 05, 28, 00:00:00 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 ------ ------ ----- ----- ----- ------ ------ ----- ----- ----- -------- ------- ----- ----- ------- ---- ---- ---- ---- ---- ---- 0.0 1018.2 25.7 15.7 54.0 -3.9 -3.3 5.1 50.0 999.0 -93.200 30.100 999.0 999.0 5.0 99.0 99.0 99.0 99.0 99.0 9.0 4.9 1015.0 25.5 15.6 54.0 -3.8 -3.1 4.9 51.0 5.7 9999.000 999.000 999.0 999.0 32.9 99.0 99.0 99.0 99.0 99.0 99.0 12.8 1010.0 25.2 15.0 53.0 -3.8 -2.8 4.7 54.0 5.5 9999.000 999.000 999.0 999.0 76.4 99.0 99.0 99.0 4.0 4.0 99.0 20.8 1005.0 24.8 14.5 53.0 -3.6 -2.6 4.5 54.0 5.5 9999.000 999.000 999.0 999.0 120.0 99.0 99.0 99.0 4.0 4.0 99.0 4.0 Quality Control Procedures No additional quality control was applied to this dataset. The quality control procedures were conducted on the high resolution data set and the results were applied during the interpolation (see above). 5.0 Composite Sounding Platforms The sites included within the 5mb resolution sounding composite include: National Weather Service (NWS) ID SITE STATE LONG LAT ELEV (m) SONDE TYPE ------------------------------------------------------------------ ABR Aberdeen SD -98.4 45.5 397.0 Vaisala AMA Amarillo TX -101.7 35.2 1094.0 Vaisala APX Gaylord MI -84.7 44.9 448.0 Vaisala BIS Bismarck ND -100.7 46.8 505.0 VIZ B2 BNA Nashville TN -86.6 36.2 180.0 VIZ B2 BMX Birminghamn AL -86.8 33.2 178.0 Vaisala ILX Central Illinois IL -89.3 40.2 178.0 Vaisala MPX Minneapolis MN -93.6 44.8 290.0 Vaisala ILN Cincinnati OH -83.7 39.4 323.0 Vaisala DVN Davenport IA -90.6 41.6 229.0 Vaisala DNR Denver INT APT CO -104.9 39.8 1611.0 Vaisala DDC Dodge City KS -100.0 37.8 788.0 VIZ B2 GRB Green Bay WI -88.1 44.5 214.0 VIZ B2 GSO Greensboro NC -79.9 36.1 277.0 Vaisala INL International Falls MN -93.4 48.5 361.0 Vaisala FFC Atlanta GA -84.6 33.4 245.0 Vaisala PIT Pittsburgh PA -80.2 40.5 360.0 VIZ B2 FWD Fort Worth TX -97.3 32.8 198.0 Vaisala JAX Jacksonville FL -81.7 30.5 9.0 Vaisala JAN Jackson MS -90.1 32.3 91.0 VIZ B2 LIT Little Rock AR -92.3 34.8 172.0 Vaisala MAF Midland TX -102.2 32.0 873.0 Vaisala OUN Norman OK -97.4 35.2 357.0 Vaisala LBF North Platte NE -100.7 41.1 849.0 Vaisala LCH Lake Charles LA -93.2 30.1 5.0 Vaisala OAX Valley NE -96.4 41.3 350.0 Vaisala UNR Rapid City SD -103.2 44.1 1029.0 Vaisala RNK Blacksburg VA -80.4 37.2 640.0 Vaisala SHV Shreveport LA -93.8 32.5 83.0 Vaisala SIL Slidell LA -89.8 30.4 10.0 Vaisala SGF Springfield MO -93.4 37.2 390.0 Vaisala TLH Tallahassee FL -84.3 30.5 53.0 Vaisala TOP Topeka KS -95.6 39.1 270.0 Vaisala DTX Detroit MI -83.5 42.7 329.0 Vaisala Atmospheric Radiation Measurement - Clouds And Radiation TestBed (ARM-CART) ID SITE STATE LONG LAT ELEV (m) SONDE TYPE ------------------------------------------------------------------ SC1 central Facility OK -97.49 36.6 315.0 Vaisala Atmospheric Technology Divison - (ATD) National Center for Atmospheric Research - Integrated Sounding System or NCAR-ISS and the Mobile Integrated Profiling System (MIPS) which is owned and operated by the University of Alabama, Huntsville ID SITE STATE LONG LAT ELEV (m) SONDE TYPE ------------------------------------------------------------------ BX1 Mobile1 NCAR GLASS Vaisala BX2 Mobile2 NCAR GLASS Vaisala BX3 MIPS NCAR GLASS Vaisala Dropsonde ID SITE STATE LONG LAT ELEV (m) SONDE TYPE ------------------------------------------------------------------ LEAR Lear Jet GPS Dropsonde 6.0 Reference Bolton, D., 1980: The Computation of Equivalent Potential Temperature. Mon. Wea. Rev., 108, 171-180.