National Weather Service (NWS) High Resolution Radiosonde Data 1.0 General Description This is one of the upper air data sets developed for the Ice in Clouds Experiment - Tropical (ICE-T) 2011 project. This data set includes 60 high vertical resolution (1-second) Radiosonde Replacement System (RRS) soundings from National Weather Service (NWS) rawinsonde stations. This ICE-T data set includes data from 1 July 2011 through 31 July 2011 for the NWS station in San Juan, Puerto Rico. The soundings were typically released twice a day (0000 and 1200 UTC). The data are in EOL Sounding Composite format (columnar ascii). 1.1 Data Set Contact Steve Williams NCAR/EOL sfw@ucar.edu 2.0 Detailed Data Description 2.0.1 National Weather Service High-Resolution Sounding Algorithms The detailed description of the NWS Radiosonde Replacement System (RRS) sounding collection and instrumentation is located in http://www.ua.nws.noaa.gov/RRS.htm 2.1 Detailed Format Description All upper air soundings were converted to the National Center for Atmospheric Research/Earth Observing Laboratory (NCAR/EOL) Sounding Composite Format (ESC). ESC 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 information. 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 field. 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 release site. 4 Release Location (lon,lat,alt): Position of release 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 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. The seven non-standard header lines may contain any label and contents. The labels are padded to 35 characters to match the standard header lines. Records for the RRS data at the remaining stations include the following non-standard header lines: 6 Ascension Number: 64 7 Radiosonde Serial Number: 85081439 8 Balloon Manufacturer/Type: Kaysam / GP26 9 Balloon Lot Number/Weight: 8 / 0.700 10 Radiosonde Type/RH Sensor Type: Sippican Mark IIA with chip thermistor, pressure / Sippican Mark IIA Carbon Hygristor 11 Surface Observations: P: 958.1, T: -2.6, RH: 65.0, WS: 10.8, WD: 305.0 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 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 Elevation Angle Degrees 999.0 14 5 F5.1 Azimuth Angle 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 NCAR Earth Observing Laboratory (NCAR/EOL). Any QC information from the original sounding is replaced by the following EOL 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 is a sample record of ICE-T 2011 NWS Radiosondee upper air data in EOL ESC format. The data portion is much longer than 80 characters and, therefore, may wrap around to a second line. See section 2.1 for an exact format specification Data Type: National Weather Service Sounding/Ascending Project ID: ICE-T_2011 Release Site Type/Site ID: TJSJ San Juan, PR / 78526 Release Location (lon,lat,alt): 065 59.51'W, 18 25.88'N, -65.992, 18.431, 3.0 UTC Release Time (y,m,d,h,m,s): 2011, 07, 10, 11:08:26 Ascension Number: 376 Radiosonde Serial Number: 85208848 Balloon Manufacturer/Type: Other / GP26 Balloon Lot Number/Weight: 91 / 0.700 Radiosonde Type/RH Sensor Type: Sippican Mark IIA with chip thermistor, pressure / Sippican Mark IIA Carbon Hygristor Surface Observations: P: 1015.9, T: 999.0, RH: 91.0, WS: 2.1, WD: 113.0 Nominal Release Time (y,m,d,h,m,s):2011, 07, 10, 12:00:00 Time Press Temp Dewpt RH Ucmp Vcmp spd dir Wcmp Lon Lat Ele Azi Alt Qp Qt Qrh 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 1015.9 26.6 24.8 90.0 -2.3 1.0 2.5 113.5 999.0 -65.992 18.431 999.0 999.0 3.0 2.0 2.0 2.0 1.0 1.0 9.0 1.0 1015.7 26.3 24.5 90.0 -2.6 0.4 2.6 98.7 2.0 -65.992 18.431 999.0 999.0 5.0 2.0 2.0 3.0 1.0 1.0 99.0 2.0 1015.1 26.2 24.4 90.0 -2.9 -0.2 2.9 86.1 6.0 -65.992 18.431 999.0 999.0 11.0 2.0 1.0 3.0 1.0 1.0 99.0 3.0 1014.4 26.2 24.4 90.1 -3.0 -0.2 3.0 86.2 5.0 -65.992 18.431 999.0 999.0 16.0 1.0 1.0 3.0 1.0 1.0 99.0 4.0 1013.7 26.2 24.4 90.1 -3.2 -0.2 3.2 86.4 6.0 -65.992 18.431 999.0 999.0 22.0 1.0 1.0 3.0 1.0 1.0 99.0 2.2 Station List ID SITE STATE COUNTRY LAT LONG ELEV (m) SONDE TYPE ------------------------------------------------------------------------- TJSJ San Juan -- PR 18.4 -66.0 3.0 Sippican Mark IIA These soundings utilized the Global Positioning System (GPS) to derive the winds. NCAR/EOL did no additional processing to the wind data provided in these soundings. NCAR/EOL utilized the processed version of the RRS data. This means the data were smoothed and had corrections applied (e.g. solar radiation correction) by the NWS. NCAR/EOL conducted no additional processing to the data values. However, additional quality assurance was applied as described in the following section. 3.0 Quality Control Processing This dataset underwent an 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 EOL can be found in Loehrer et al. (1996) and Loehrer et al. (1998). 3.1 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. EOL conducted the following gross limit checks on the T-REX NWS sounding dataset. 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 < -90C or > 45C T Q Dew Point < -99.9C or > 33C 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 < -10 m/s or > 10 m/s P, T, RH Q _________________________________________________________________ 3.2 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 6-sec data points (except at pressures less than 100 mb where 30-sec average values were used. 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 decreasing/equal None None Altitude decreasing/equal P, T, RH Q Pressure increasing/equal P, T, RH Q > 1 mb/s or < -1 mb/s P, T, RH Q > 2 mb/s or < -2 mb/s P, T, RH B Temperature < -15 C/km P, T, RH Q < -30 C/km P, T, RH B > 50 C/km (not applied at p < 250mb) P, T, RH Q > 100 C/km (not applied at p < 250mb) 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 _____________________________________________________________________ 3.3 Visual Checks All soundings were visually examined utilizing the EOL XQC tool which allows data quality flags to be adjusted. Visual examination is conducted only up to 50mb. 3.4 Data Quality Comments None. 5.0 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.