SGP99 NOAA Radio Acoustic Sounding System (RASS) and 405 MHZ Wind Profiler Network Dataset 1.0 General Description The National Oceanic and Atmospheric Administration (NOAA) 405 MHZ Wind and Radio Acoustic Sounding System (RASS) Profiler Network (NPN) dataset consists of hourly profiles from ten sites within the Southern Great Plains 1999 (SGP99) project domain. See Section 2.0 for a list of sites. This dataset covers the complete SGP99 time period (1 July 1999 through 31 July 1999) and domain. The SGP99 domain is approximately 97W to 99W longitude and 34.5N to 37N latitude. Further details regarding the operation of the NPN can be found in Van de Kamp, 1988. The dataset contains merged wind and RASS virtual temperature profiles and individual wind and/or RASS virtual temperature profiles. Whenever a NPN site retrieved both a wind profile and a RASS virtual temperature profile during the same hour, then the profiles were combined into one profile. No additional quality control was performed by the University Corporation for Atmospheric Research/Joint Office for Science Support (JOSS). 2.0 Detailed Data Description The NPN 405 MHZ Wind and RASS profiler data was converted by JOSS from E-BUFR (Enhanced Binary Universal Format for the Representation of meteorological data)format to a tabular ASCII format: JOSS Cross Chain LORAN Atmospheric Sounding System (CLASS) Format (JCF). A detailed description of JCF is provided in Section 2.1. 2.0.1 NPN 405 MHZ Wind Profiler The 405 MHZ Wind Profiler data consists of a series of hourly observations, each containing approximately 64 levels of wind speed and direction data, ranging from 0.50 to 16.25 km above the station. The 64 levels consist of 28 observations from the "low" mode and 36 observations from the "high" mode. Low mode of the profiler starts at 0.50 km above the station, with 250 m spacing between each gate or level. There is a height resolution of 250 m in low mode. The source data contains 36 low mode gates; so, the highest low mode gate will be at 9.25 km above the station. High mode of the profiler starts at 7.50 km above the station, with 250 m spacing between each gate or level. There is a height resolution of 1000 m in high mode. The source data contains 36 high mode gates; so, the highest high mode gate will be at 16.25 km above the station. Thus, for heights above the station from 7.50 km to 9.25 km, there are data from both low and high mode gates in the source data. All low mode gates in this overlap area are discarded unless high mode data area missing. The exact number of low and high mode gates included in the SGP 1999 dataset will vary from observation to observation, due to missing data in the source. In the overlap area, there is no distinction in the SGP 1999 data as to whether the gate/level was obtained from a low mode or a high mode gate. 2.0.2 NPN RASS Virtual Temperature The National Climatic Data Center (NCDC) provides hourly Radio Acoustic Sounding System (RASS) data for the Wind Profiler Demonstration Network (WPDN) on a daily basis in E-BUFR format. The RASS measures temperature profiles in the lower troposphere. Its sensors work in combination with the wind profiler Doppler radars to produce virtual temperature. RASS emits an acoustic signal whose propagation velocity is measured by the wind profiling radar. The propagation velocity, the speed of sound measured at each level, is converted to a virtual temperature. The accuracy is better than 1 degree C. The altitude to which RASS can measure is limited for two reasons: 1) The stronger the horizontal wind, the greater the likelihood that the acoustic signal will be carried out of the radar beam. For this reason, many installations place acoustic sources at all four corners of the wind profiling radar. 2) The acoustic signal is strongly attenuated in air. RASS measurements with the 404-MHz profilers typically extend up to 3-4 km above ground. 2.0.3 SGP99 NOAA RASS and 405 MHZ Wind Profiler Sites The tables below contain each site's latitude, longitude, elevation, date of installation, and the vertical displacement between the antenna phase center and the station's pressure sensor. A "*" denotes NOAA's Wind Profiler Demonstration Network (WPDN) RASS stations. SGP99 NOAA Wind Profiler Sites ID Location Lat Lon Ele Date Psfc (m) (m) ------------------------------------------------------------------------ GDAC GRANADA CO 37.78 -102.18 1159 17-Oct-96 0.5850 HKLO *HASKELL OK 35.68 -95.86 221 19-Apr-95 0.5850 HVLK *HAVILAND KS 37.65 -99.11 648 29-May-96 0.5030 HBRK *HILLSBORO KS 38.30 -97.29 443 5-Jul-96 0.5600 JTNT JAYTON TX 33.02 -100.98 711 22-May-97 0.5420 LMNO LAMONT OK 36.69 -97.48 308 22-Nov-94 0.5580 NDSK NEODESHA KS 37.38 -95.64 256 6-Sep-96 0.5050 PATT PALESTINE TX 31.78 -95.72 121 23-May-97 0.3920 PRCO *PURCELL OK 34.98 -97.52 331 28-Nov-95 0.8740 VCIO *VICI OK 36.07 -99.22 653 13-Apr-95 0.5910 2.1 Detailed Format Description Observations are an hour average from the preceding hour of data. The previous hour's six minute observations are processed to derive an hourly average using a consensus procedure (Barth et al., 1994) All NPN RASS and Wind profiles 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 profile 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 Profile Site Type/Site ID: Description of launch site. 4 Profile Location (lon,lat,alt): Position of launch site, in format described below. 5 UTC Profile Time (y,m,d,h,m,s): Time of release, in format: yyyy, mm, dd, hh:mm:ss 6 Ascension No: Ascension number of the site for the year . 7 Radiosonde Serial Number: Serial number of this radiosonde. 8 Radiosonde Manufacturer: Manufacturer of this radiosonde. 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 label is padded to 35 characters to match the standard header lines. 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 Virtual Temp (RASS profiles)Degrees 999.0 13 5 f5.1 Range (Wind only profiles) 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 profile 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 is a sample record of SGP99 NPN RASS virtual temperature and wind profile 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 specification. Data Type: Profile Project ID: SGP-99 NOAA Profiler RASS Virtual Temp and Wind Profiles Profile Site Type/Site ID: PURCELL,OK PRCO Profile Location (lon,lat,alt): 097 31.20'W, 34 58.80'N, -97.52, 34.98, 331.0 UTC Profile Time (y,m,d,h,m,s): 1999, 07, 01, 00:00:00 System Operator/Comments: Site's installation date is 28-Nov-95 and vertical displacement between the antenna phase Additional comments: center and the station's pressure sensor is 0.8740 meters Additional comments: Field 13 contains Virtual Temperature in Kelvins / / / Nominal Profile Time (y,m,d,h,m,s):1999, 07, 01, 00:00:00 Time Press Temp Dewpt RH Uwind Vwind Wspd Dir dZ Lon Lat VirT Azim Alt Qp Qt Qh Qu Qv Qdz sec mb C C % m/s m/s m/s deg m/s deg deg K deg m code code code code code code ------ ------ ----- ----- ----- ------ ------ ----- ----- ----- -------- ----- -- ----- ----- ------- ---- ---- ---- ---- ---- ---- 9999.0 9999.0 999.0 999.0 999.0 0.4 8.5 8.5 183.0 999.0 9999.000 999.000 301.5 999.0 831.0 9.0 9.0 9.0 99.0 99.0 9.0 9999.0 9999.0 999.0 999.0 999.0 0.8 9.0 9.0 185.0 999.0 9999.000 999.000 299.8 999.0 1081.0 9.0 9.0 9.0 99.0 99.0 9.0 9999.0 9999.0 999.0 999.0 999.0 4.1 11.2 11.9 200.0 999.0 9999.000 999.000 297.5 999.0 1331.0 9.0 9.0 9.0 99.0 99.0 9.0 9999.0 9999.0 999.0 999.0 999.0 7.3 12.6 14.6 210.0 999.0 9999.000 999.000 294.7 999.0 1581.0 9.0 9.0 9.0 99.0 99.0 9.0 The following is a sample record of SGP99 NPN 405 MHZ Wind only profile 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 specification. Data Type: Profile Project ID: SGP-99 NOAA Profiler RASS Virtual Temp and Wind Profiles Profile Site Type/Site ID: PALESTINE,TX PATT Profile Location (lon,lat,alt): 095 42.60'W, 31 46.80'N, -95.71, 31.78, 119.0 UTC Profile Time (y,m,d,h,m,s): 1999, 07, 01, 00:00:00 System Operator/Comments: Site's installation date is 23-May-97 and vertical displacement between the antenna phase Additional comments: center and the station's pressure sensor is 0.3920 meters / / / / Nominal Profile Time (y,m,d,h,m,s):1999, 07, 01, 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 ------ ------ ----- ----- ----- ------ ------ ----- ----- ----- -------- ------- ----- ----- ------- ---- ---- ---- ---- ---- ---- 9999.0 9999.0 999.0 999.0 999.0 -0.7 13.6 13.6 177.0 999.0 9999.000 999.000 999.0 999.0 619.0 9.0 9.0 9.0 99.0 99.0 9.0 9999.0 9999.0 999.0 999.0 999.0 1.4 13.0 13.1 186.0 999.0 9999.000 999.000 999.0 999.0 869.0 9.0 9.0 9.0 99.0 99.0 9.0 9999.0 9999.0 999.0 999.0 999.0 3.3 13.1 13.5 194.0 999.0 9999.000 999.000 999.0 999.0 1119.0 9.0 9.0 9.0 99.0 99.0 9.0 9999.0 9999.0 999.0 999.0 999.0 5.6 13.8 14.9 202.0 999.0 9999.000 999.000 999.0 999.0 1369.0 9.0 9.0 9.0 99.0 99.0 9.0 Questions regarding the content of the data stream should be directed to Alice Cialella, cialella@bnl.gov, 631-344-3286. 2.2 Data Remarks This data is provided "as is". 3.0 Quality Control Processing These data were not quality controlled by the University Corporation for Atmospheric Research/Joint Office for Science Support (UCAR/JOSS). 4.0 References ARM, 2000: A description of the three quality control algorithms currently implemented by the Wind Profiler Demonstration Network's Hub software. [Available on-line from http://www.xdc.arm.gov/docs/data_info/sgp/qcalgo.txt] ARM, 2000: Release Notice for Wind Profiler Demonstration Network (WPDN) Hourly, November 21, 1996. [Available on-line from http:// www.xdc.arm.gov/docs/data_info/release_forms/sgp60wpdnrass.release.html] Barth, M. F., R. B. Chadwick, and D. W. van de Kamp, 1994. Data processing algorithms used by NOAA's Wind Profiler Demonstration Network, Annales Geophysicae, 12, 512-528. Forecast Systems Laboratory (FSL), May 1996, FSL in Review- Fiscal Year 1995, U.S. Department of Commerce, National Oceanic and Atmospheric Research, Boulder, CO, 102 pp. National Weather Service and the Office of Oceanic and Atmospheric Research, August 1994, Wind Profiler Assessment Report and Recommendations for Future Use 1987-1994, U.S. Department of Commerce, National Oceanic and Atmospheric Research, Silver Spring, Maryland, 141 pp. NOAA, 2000: NOAA Profiler Network Data Description. [Available on-line from http://www-dd.fsl.noaa.gov/descrip.html] Van de Kamp, D.W., 1988: Profiler Training Manuals (No.1 through 4). NOAA/ERL Forecast Systems Laboratory, Boulder, Co.