UMRBPP NOAA 405 MHZ Wind Profiler Network Data Set 1.0 General Description The National Oceanic and Atmospheric Administration (NOAA) 405 MHZ Wind Profiler Network (NPN) dataset provided in the Upper Missouri River Basin Pilot Project (UMRBPP) contains hourly wind profiler data from the Merriman, Nebraska site. Data are available for the periods from 19990405 through 19990419 and from 19990422 through 19990425. The Merriman profiler was not operational from 1200 UTC 19 April to 0200 UTC 22 April and from 2300 UTC 25 April to 24 May 1999 and no data are available during these period. Further details regarding the operation of the NPN can be found in Van de Kamp, 1988. 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 data is provided in an ASCII format suitable for display on a pc with the profiler plotting program "windprof.exe" distributed by the University Corporation for Atmospheric Research/Joint Office for Science Support (UCAR/JOSS). 2.0 Detailed Data Description The 405 MHZ Wind Profiler data set has been converted from Enhanced BUFR format to an ASCII format suitable as input for the wind profiler plotting/display program "windprof" distributed by UCAR/JOSS. Each data file contains a series of observations for a single station. Each observation corresponds to a particular date and time for that station, and contains a series of gates, or levels, that report the wind speed and direction at a particular height above the station. Each observation consists of a header section and a data section. A line consisting only of a dollar sign ('$') ends the observation (and thus also the data section). The data file begins with a single blank line before the first observation. 2.1 Detailed Format Description Header Information The header information contains the 3-character station identifier, latitude, longitude, and elevation of the station, and the date, time, and time zone offset from UTC. The time zone offset is the number of hours to add to UTC to find local time. For example, Eastern Standard Time (EST) of the USA has an offset of -5. All times in this data are given in UTC (thus all offsets are 0). In the original input data, the header information also contains several unused fields which are set to 0 or 0.0 depending on whether the field is an integer or floating point field. These unused fields are used to record specific information for research profilers which is not available with the NPN data. Data Information The data information section consists of a sequence of data lines, one for each level above the station. The number of levels (and thus the number of lines in the data section) is indicated in header information section. Each data line consists of the following parameters shown below: Parameters Units ----------------------------------------------- Altitude km Wind speed m/s Wind direction deg U wind component m/s V wind component m/s W wind component m/s East consensus number North consensus Vertical consensus Quality control key Quality control indicator Quality control summary Missing values are encoded as 9999.00 (for floating point fields) or 9999 (for integer fields). The quality control indicator (QCi) is taken from the value for BUFR code 0 33 208 in the source data, and the quality control summary (QCs) is taken from the value for BUFR code 0 33 210 in the source data. The quality control key (QCk) actually resides in the data field reserved for signal noise level and is used by "windprof" program as a user-specified cutoff value that determines which data gets displayed or plotted. If QCi is 0 ("Passed all checks") and QCs is 2 ("Passed all applicable tests"), then all three QC values (QCk, QCi, QCs) contain the Missing value (9999). Otherwise, QCi and QCs contain their actual values from the source data. If QCs is 1 ("No wind available"), then QCk will have a value of -99. Otherwise, QCk will have the value -11*QCs. This allows the user to select various levels of QC information when displaying or plotting profiler data from the "windprof" program, which ordinarily does not allow that. If the wind speed and/or direction were "Missing" in the source data, and the u and v wind components were present, then the missing values were computed from the u and v components, and QCk will have the value -11*QCs - 1. There are generally 64 levels in the data section: 28 from "low" mode and 36 from "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 UMRBP dataset will vary from observation to observation, due to missing data in the source. In the overlap area, there is no distinction in the UMRBP data as to whether the gate/level was obtained from a low mode or a high mode gate. 2.2 Data Remarks If the source data had a gate/level with all data fields recorded as "Missing", then that gate/level was not included in these data files. As noted above, if the wind speed and/or direction were "Missing" in the original data, and the u and v wind components were present, then the missing values were computed from the u and v components, and the first QC value was changed to indicate this (see above). All times are reported in Universal Coordinated Time (UTC). 3.0 Quality Control Processing No additional quality control was performed on this dataset by UCAR/JOSS. 4.0 References Van de Kamp, D.W., 1988: Profiler Training Manuals (No.1 through 4). NOAA/ERL Forecast Systems Laboratory, Boulder, Co.