SGP99 MAPS Model Location Time Series (MOLTS) 1.0 General Description The MAPS Model Location Time Series is one of the model output datasets provided in the Southern Great Plains - 1999 (SGP99). The full MAPS MOLTS dataset covers most of North America east of the Rocky Mountains (283 locations). MOLTS are hourly time series output at selected locations that contain values for various surface parameters and `sounding' profiles at MAPS model levels and are derived from the MAPS model output. The MOLTS output files were converted into JOSS Quality Control Format (QCF) the same format used for atmospheric rawinsonde soundings processed by JOSS. The MOLTS output provided by JOSS on-line includes only the initial analysis output (i.e. no forecast MOLTS) and only state parameters (pressure, altitude, temperature, humidity, and wind). The full output, including the forecast MOLTS and all output parameters, in its orignal format (BUFR) is available from the NCAR/Scientific Computing Division. 2.0 Detailed Data Description The Forecast Systems Laboratory (FSL) operates the MAPS model with a resolution of 40 km and 40 vertical levels. The MAPS analysis and forecast fields are generated every 3 hours at 0000, 0300, 0600, 0900, 1200, 1500, 1800, and 2100 UTC daily. MOLTS are hourly vertical profile and surface time series derived from the MAPS model output. The complete MOLTS output includes six informational items, 16 parameters for each level and 27 parameters at the surface (a full listing is provided in section 2.2). Output are available each hour beginning at the initial analysis (the only output available from JOSS) and ending at the 48 hour forecast. JOSS converts the raw format files into JOSS QCF format which is the same format used for atmospheric sounding data such as NWS soundings. A description of JOSS QCF format is included within section 2.1. JOSS calculated the total wind speed and direction from the u and v wind components. JOSS calculated the mixing ratio from the specific humidity (Pruppacher and Klett 1980) and the dew point from the mixing ratio (Wallace and Hobbs 1977). Then the relative humidity was calculated from the dew point (Bolton 1980). JOSS did not conduct any quality control on this output. 2.1 Detailed Format Description 2.1.1 Header records The header records (15 total records) contain output type, project ID, the location of the nearest station to the MOLTS location (this can be a rawinsonde station, an ARM/CART station, a wind profiler station, a surface station, or just the nearest town), the location of the MOLTS output, and the valid time for the MOLTS output. The 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 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 six standard header lines are as follows: Line Label (fixed to 35 char in length) Contents 1 Output Type: Description of type of data. 2 Project ID: ID of weather project. 3 Nearest Station (lon,lat): Description of the nearest location. 4 Output Location (lon,lat,alt): Position of MOLTS output in format described below. 5 Valid Time (y,m,d,h,m,s): Time of release in UTC, in format: yyyy, mm, dd, hh:mm:ss 6 CAUTION: A warning that this is not actual rawinsonde data, but rather model output. 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 fixed to 35 characters to match the standard header lines. Sample header records are provided in the sample data file in section 2.1.3. 2.1.2 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. For the MOLTS output, these columns have been set to missing. Fields 16 through 21 contain the Quality Control information (flags) generated locally at JOSS. These flags are based on the automatic or visual checks made. See Sections 3.0 and 4.0 for further information. 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') 2.1.3 Sample data The following is a sample portion of an JOSS QCF file including header records. The data portion is much longer than 80 characters and, therefore, wraps around to a second line. Data Type: MAPS MOLTS Project ID: GCIP class format derived sounding Launch Site Type/Site ID: MUZQUIZ, COAH. MEXICO 90003 Launch Location (lon,lat,alt): 102 30.00'W, 27 42.00'N, -102.50, 27.70, 99999.0 GMT Launch Time (y,m,d,h,m,s): 1997, 08, 08, 12:00:00 CAUTION: This is not actual rawinsonde data, it is output from the FSL MAPS model initial analysis. / / / / / Nominal Launch Time (y,m,d,h,m,s): 1997, 08, 08, 12:00:00 Time Press Temp Dewpt RH Uwind Vwind Wspd Dir dZ Lon Lat Rng Ang Alt Qp Qt Qh Qu Qv Qdz sec mb C C % m/s m/s m/s deg m/s deg deg km deg m code code code code code code ------ ------ ----- ----- ----- ------ ------ ----- ----- ----- -------- ------- ----- ----- ------- ---- ---- ---- ---- ---- ---- 9999.0 846.6 17.5 14.9 85.2 -0.8 -2.3 2.4 19.0 999.0 -102.500 27.700 999.0 999.0 99999.0 99.0 99.0 99.0 99.0 99.0 99.0 9999.0 846.6 17.5 14.9 85.2 -0.8 -2.3 2.4 19.0 999.0 -102.500 27.700 999.0 999.0 1595.0 99.0 99.0 99.0 99.0 99.0 99.0 9999.0 844.9 17.4 14.8 84.9 -0.4 -2.7 2.7 8.0 999.0 -102.500 27.700 999.0 999.0 1613.0 99.0 99.0 99.0 99.0 99.0 99.0 . . . etc. 2.2 Full FSL/MAPS MOLTS parameter listing for GCIP As previously mentioned, the full MOLTS output is not avaialbe from JOSS. It is, however, available from NCAR/SCD. A listing of the parameters available follows. Identifiers Forecast Time Station Number Latitude Longitude Station Elevation Class of Profile Output Atmospheric Parameters at Each Model Vertical Level Pressure Geopotential Height Temperature Specific Humidity U Wind Component V Wind Component Omega Convective Latent Heating Rate Stable Latent Heating Rate Short-wave Heating Rate Long-wave Heating Rate Cloud Water Mixing Ratio Rain Mixing Ratio Snow Mixing Ratio Ice Mixing Ratio Graupel Mixing Ratio Surface Parameters Pressure at Mean Sea Level Surface Pressure 1-hr Accumulated Total Precipitation 1-hr Accumulated Convective Precipitation U Wind Component at 10 m V Wind Component at 10 m 2 m Specific Humidity 2 m Temperature Skin Temperature 1-hr Average Flux of Latent Heat 1-hr Average Flux of Sensible Heat 1-hr Ground Heat Flux 1-hr Surface Momentum Flux 1-hr Average Flux of Snow Phase Change Snow Water Equivalent 1-hr Accumulated Snow Melt 1-hr Accumulated Surface Runoff 1-hr Accumulated Baseflow-groundwater Runoff 1-hr Average Short-wave Radiation Downward Flux 1-hr Average Short-wave Radiation Upward Flux 1-hr Average Long-wave Radiation Downward Flux 1-hr Average Long-wave Radiation Upward Flux 1-hr Average Net Long-wave Radiative Flux at Top 1-hr Average Net Short-wave Radiative Flux at Top Top-of-Atmosphere Pressure Multi-Layer Soil Temperature Multi-Layer Volumetric Soil Moisture 2.3 Data Remarks No remarks. 3.0 Quality Control Processing No quality control was performed by JOSS. 4.0 References Bolton, D., 1980: The Computation of Equivalent Potential Temperature. Mon. Wea. Rev., 108, 171-180. Pruppacher, H. R., and J. D. Klett, 1980: Microphysics of Clouds and Precipitation. D. Reidel Publishing Company. 714 pp. Wallace, J. M., and P. V. Hobbs, 1977: Atmospheric Science: An Introductory Survey. Academic Press. 467 pp.