IHOP 2002 TAOS Soundings Contacts/PIs: Dave Parsons parsons@ucar.edu Tammy Weckwerth tammy@ucar.edu Mailing Address: NCAR/Atmospheric Technology Division P.O. Box 3000 1850 Table Mesa Drive Boulder, CO 80307; USA Data Inquiry Contacts: Ned Chamberlain chamberl@ucar.edu Timothy Lim tdlim@ucar.edu Kate Young kbeierle@ucar.edu I. Data Set Overview IHOP ISS/Mobile Glass information: http://www.atd.ucar.edu/rtf/projects/ihop_2002/iss/ ATD Mobile Glass/TAOS information: http://www.atd.ucar.edu/rtf/facilities/class/class.html Time period covered: 6/12/02 - 6/21/02 II. TAOS Information The Tethered Atmospheric Observing System (TAOS) used during the IHOP project was located one mile east of the Homestead site, on the south side of the road (Lat 36 deg 33.500 min N, Lon 100 deg 36.371 min W, Alt 850 m). The tethered system is comprised of up to eight NCAR designed and built sensor platforms using the Vaisala RS-90 P, T, and RH sensor package for these measurements. Wind speed comes from an R.M. Young propellor using an optical chopper. Wind direction comes from a Honeywell magnetometer which provides pitch and roll information in addition to direction. The sensor packages are tethered to a large balloon, and are spaced apart at various altitudes along a line attached to the balloon. Each tranmits one second resolution data simultaneoulsy over a period of time. The IHOP TAOS datasets were collected on June 12, 14, and 21 of 2002. III. Data Records Field Parameter Units Missing Value No. ------------------------------------------------------------------------------------------ 1 Channel Number* 2 Atmospheric Pressure Millibars 3 Atmospheric Temp Degrees C -999.9 4 Relative Humidity #1 Percent -999.9 5 Relative Humidity #2 Percent -999.9 6 Wind Speed Meters/Second 7 Wind Direction Degrees 8 Sensor Module Internal Temp Degrees C 9 Pitch Degrees 10 Roll Degrees 11 Battery Voltage Watts 12 Day of Year 13 Time hh:mm:ss *Each channel number represents a different sensor package. IV. Data Quality Control The TAOS dataset underwent some manual quality control procedures to fix the following problems. During the flights, heaters designed to evaporate condensation after the humidity sensor passed through a cloud turned on and off at random. This resulted in the relative humidity values dropping by between 2-10 percent for short periods of time and then rebounding. These errors in the dataset were identified by examining and comparing the time series of the RH1 and RH2 sensor data and replacing the erroneous data with -999.9. There was also a problem with the time-stamp feature, which in some cases caused multiple entries for the same sensor package at the same times. These duplicates were removed from the dataset. Pressure and temperature outliers were also replaced with -999.9.