Davao TOGA-COARE High-Resolution Sounding Dataset 1.0 Site Information Location: 125.65 Deg E Longitude 7.12 Deg N Latitude Station Elevation: 18 m Typical Launch Times: 00 12 UTC Dates Available: 2 Nov 1992 - 10 Nov 1992 15 Nov 1992 - 28 Feb 1993 (scattered missing files) Total Launches Available in `Native Resolution': 0 Total Launches Available in GTS Format Only: 225 (14 files have only 60/120 sec winds) 2.0 Radiosonde Information Radiosonde Type: ? Radiation Correction Applied?: ? Ground Equipment: ? Windfinding System: ? Windfinding Equipment: ? Resolution of Raw Data: variable (GTS) 3.0 Parameters in Raw Dataset 3.1 BoM GTS Parameters Units ------------------------------------- Pressure Millibars Altitude Meters or Feet Wind Direction Deg Wind Speed Kts ------------------------------------- 3.2 ECMWF GTS Parameters Units ------------------------------------- Pressure Pascal Geopotential m^2/s^2 Wind Direction Deg Wind Speed Kts ------------------------------------- NOTE: Parameters available depend on the type of GTS message. 3.3 60, 120 sec vertical resolution wind files Parameters Units ------------------------------------- Time Seconds Wind direction Deg Wind Speed m/s ------------------------------------- 4.0 Conversion to OFPS CLASS 4.1 This data was collected from the Australian Bureau of Meteorology (BoM) and the European Centre for Medium-Range Weather Forecasts GTS archives. Of the 211 releases, 197 were from BoM and 14 were from ECMWF. The header of each file provides information on which archive the data is from. 4.2 Davao had only wind observations, except for one release (10 January 1993). 4.3 The GTS data included many errors (typos, etc). When the error made was obvious (transposed numbers, etc), OFPS corrected the error. If there was a single error, that did not have an obvious correction, OFPS removed the data point. When several data points in a row had similar errors, OFPS assumed that the error was due to radiosonde problems and kept the data (but did flag the data). NOTE: This procedure was only applied to the BoM GTS data. This procedure was not conducted for the ECMWF GTS data as OFPS did not have the actual GTS messages. While OFPS has made every effort to clear as many of the problem data points as possible, there may still be many errors. This is especially true for the wind and dew point data with their possible high variability and the wide spacing of data in GTS. OFPS suggests that caution be used in the consideration of this data. Again, OFPS made NO attempt to clear the problem data points in the ECMWF GTS data, due to the lack of the original GTS messages. Problem data points were, however, flagged during the procedures described later. 4.4 ECMWF would like to pass along the following message: `Please note that although every care was taken in preparing and testing the data, ECMWF cannot guarantee that the data are correct in all circumstances, neither does ECMWF accept any liability whatsoever for any error or omission in the data, or for any loss or damage arising from its use.' 4.5 For ECMWF GTS data only: 4.5.1 Convert pressure from Pa to mb. 4.5.2 Convert Temperature from Deg K to Deg C. 4.5.3 Convert Dew Point from Deg K to Deg C. 4.5.4 Convert wind speed from Kts to m/s. 4.5.5 Convert geopotential to geopotential meters. 4.6 The 60/120 second wind files were intermingled with the GTS files (both ECMWF and BoM). 4.7 The ascension rate was unable to be calculated due to the lack of time data. 4.8 The U and V wind components were calculated based on the wind speed and direction at a level. 4.9 The latitude and longitude position of the radiosonde was unable to be calculated due to the lack of time data. 4.10 The sorting of this data was problematic due to the presense of some data points without pressure and others without altitude. Given this, please be aware that all data points may not be in the correct order. 5.0 Automatic Quality Control Procedures Internal quality control procedures were applied to each sounding individually. These checks included two general types: `Reasonable limit' checks on all parameters and `Rate-of-Change' checks on pressure, temperature, and ascension rate. These checks led to the development of automatically generated quality control flags in the OFPS CLASS format file. Also, files were generated that contain descriptions of the problems found in each sounding. For further information on the OFPS automatic quality control procedures used for the TOGA-COARE project see Loehrer et al. (1996). 6.0 Visual Quality Control Procedures Each sounding was then visually examined for problems that are not able to be captured via the automatic checks described in item 5.0 above. These problems typically included oddities in the dew point and wind profiles. These two parameters can be highly variable, and hence, the automatic checking is more difficult. The visual checking procedure has two main purposes: First, as a check on the results provided by the automatic checks, and second, as a more stringent check on the more variable parameters. For further information on this procedure, see Loehrer et al (1996). 7.0 Spatial Quality Control Procedures Basic statistics are generated indicating whether a given station performed consistently with respect to its neighbors and the network as a whole. The first set of statistics are level-by-level checks versus neighboring stations. The neighbors are those stations in a constricted latitude band. The general methodology used by OFPS is a simple distance weighted averaging scheme comparing the observed values to those expected by the averaging scheme. Tests are applied to altitude, temperature, dew point, wind speed and direction at 14 standard pressure levels. The second set of statistics are level-by-level checks versus network-wide averages. For these all of the data from the network at a particular level and time is averaged and each site is compared to the average. For more information on the procedures used for the spatial consistency checks see Loehrer et al (1996). For general findings from the spatial QC see the OFPS spatial QC overview and findings document. The statistics from both checks are also available online. -----------------NOTE------------------NOTE------------------ Due to the nature of this data set, no spatial QC procedures will be applied. -----------------NOTE------------------NOTE------------------ 8.0 Derived Sounding Parameters The NCAR SUDS (System for User-editing and Display of Soundings; Burghart 1993) software was used to calculate common wind, thermodynamic and stability parameters using the procedures of Weisman and Klemp (1982). Any data points flagged as BAD by the automatic or visual checks are not used in the calculation of these parameters. These parameters will be online, with a separate file for each sounding. The parameters calculated by this routine include: SUDS Derived Parameters ---------------------------------------------- Surface Potential Temperature Surface Virtual Potential Temperature Surface Mixing Ratio 500 mb Potential Temperature 500 mb Virtual Temperature 500 mb Virtual Potential Temperature Lifted Condensation Level (LCL) Lifted Index Level of Free Convection (LFC) Positive Area Below the LFC Negative Area Below the LFC Convective Available Potential Energy (CAPE) Negative Area Above the LFC Shear over the Lowest 6 km Bulk Richardson Number (Ri) Mean Layer Vector Wind between 1000 and 700 mb ---------------------------------------------- 9.0 JOSS CLASS Format (ASCII text) Description 9.1 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 Launch Site Type/Site ID: Description of launch site. 4 Launch Location (lon,lat,alt): Position of launch site in format described below. 5 UTC Launch Time: Time of release, in format: yyyy, mm, dd, hh:mm:ss 12 UTC Nominal Launch Time: Nominal release time. The launch site type/site ID has the format: site ID (three or four letter code), the full site name, the country code and the WMO code for the site. 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 six non-standard header lines may contain any label and contents. The label is fixed to 35 characters to match the standard header lines. Sample header records are provided in the sample data file later in this section. 9.2 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') ---------------------------------------------------------------------- 9.3 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: Project ID: Davao native resolution soundings. Release Site Type/Site ID: Davao, PH, 98753 Release Location (lon,lat,alt): 125 39.00'E, 07 7.20'N, 125.65, 7.12, 18.0 UTC Release Time (y,m,d,h,m,s): 1992, 11, 02, 00:00:00 CAUTION: This data was derived from ECMWF GTS messages and is not guaranteed by ECMWF or UCAR OFPS. / / / / / Nominal Release Time (y,m,d,h,m,s):1992, 11, 02, 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 0.0 -1.5 1.5 360.0 999.0 9999.000 999.000 999.0 999.0 17.3 9.0 9.0 9.0 99.0 99.0 9.0 9999.0 9999.0 999.0 999.0 999.0 -4.3 -5.1 6.7 40.0 999.0 9999.000 999.000 999.0 999.0 299.8 9.0 9.0 9.0 99.0 99.0 9.0 9999.0 9999.0 999.0 999.0 999.0 -1.2 -3.4 3.6 20.0 999.0 9999.000 999.000 999.0 999.0 599.6 9.0 9.0 9.0 99.0 99.0 9.0 10.0 Usage of GTS Messages The sounding data set for Davao was composed entirely of GTS messages. The conversion procedures are described above. 11.0 Dataset Availability Datasets Available Online ---------------------------------------------------------------- Quality Controlled Data File in Native Resolution (available in Bufr, EBufr, and OFPS QCF (ASCII) formats) Statistics generated from the Horizontal Checks (see item 7.0 above) Derived Sounding Parameters (see item 8.0 above) Interpolated 5 mb Vertical Resolution Files (see item 9.0 above) Site-by-site processing and QC documentation (including special spatial QC and general QC documents) ---------------------------------------------------------------- Datasets Available Offline ---------------------------------------------------------------- Non-Quality Controlled, Raw Format File in Native Resolution Automatically generated Error Files (see item 5.0 above) ---------------------------------------------------------------- 12.0 Dataset Remarks No remarks. 13.0 References Bolton, D., 1980: The Computation of Equivalent Potential Temperature. Mon. Wea. Rev., 108, 171-180. Burghart, C., 1993: SUDS: The system for user-editing and display of soundings. Research Data Program, National Center for Atmospheric Research, Boulder, CO. Cole, H., 1993: The TOGA-COARE ISS radiosonde temperature and humidity sensor errors. Surface and Sounding Systems Facility, National Center for Atmospheric Research, Boulder, CO. Herzegh, P. H., 1988: Formulation of output parameters for PAM II CMF data. Field Observing Facility, National Center for Atmospheric Research, Boulder, CO. Hess, S. L., 1959: Introduction to Theoretical Meteorology. Holt, Rinehart and Winston, 362 pp. Holton, J.R., 1979: An Introduction to Dynamic Meteorology. Academic Press, 391 pp. 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. Weisman, M.L., and J.B. Klemp, 1982: The dependence of numerically simulated convective storms on vertical wind shear and buoyancy. Mon. Wea. Rev., 110, 504-520.