Project at a Glance
Title: Processing and validation of data collected by radar wind profilers, radio acoustic sounding systems, and sodars during the 1997 Southern California Ozone Study.
Principal Investigator / Author(s): MacDonald, Clinton P.
Contractor: Sonoma Tech
Contract Number: 99-307
Research Program Area: Atmospheric Processes
Topic Areas: Field Studies, Modeling
During the 1997 Southern California Ozone Study (SCOS97)–North American Research Strategies for Tropospheric Ozone (NARSTO), upper-air measurements of atmospheric parameters were made from June through October 1997 using a mesoscale network of in-situ and ground-based remote sensors. This upper-air meteorological monitoring network consisted of 26 915-MHz Radar Wind Profilers with Radio Acoustic Sounding System (RP/RASS), six sodars, and rawinsondes. RP/RASS wind and temperature data and sodar wind data were produced from “raw” data in 1998 by the National Oceanic and Atmospheric Administration’s (NOAA) Environmental Technology Laboratory (NOAA-ETL) (Wolfe and Weber, 1998) using two processing methods: Met_0 and Met_1. Post-processing included objective quality control (QC) of the data. However, in 1999, various users discovered inconsistencies and problems with the 1998 data, which are as follows.
· Analyses and model runs conducted using the data sets created from the 1998 post-processing/
QC task showed that the RP/RASS data sets contained data that were not meteorologically reasonable.
· By itself, the 1998 post-processing/QC task generated only Level 0.5 (objective QC only) validated meteorological data, whereas analysis and modeling efforts require a higher level of QC (Wolfe and Weber, 1998).
· The auditing process revealed problems with the setup and/or operation of certain instruments; some of these problems were fixed at the time of the audits while others were not addressed in the 1998 data set, but were addressed for the first time during this processing and validation project.
· The two processing methods (Met_0 and Met_1) produced different results, but no determination had been made as to which algorithm produced the best data for each site, effectively leaving this decision to users who do not have the necessary experience and information.
· Met_0 and Met_1 processing methods produced data points when the traditional consensus method would not have done so. These revelations raised further questions concerning the validity and quality of the data produced by the Met_0 and Met_1 processing algorithms.
The goal of this project is to address these problems and inconsistencies and to provide one final, fully validated set of upper-air data (RP/RASS wind and virtual temperature [Tv] data and sodar wind data) that incorporates all available QC information, that identifies and accounts for offsets and errors in the data, and that has received complete objective and subjective quality reviews. The end product is a higher quality, validated, single data set that can be used by analysts and modelers without the need for further judgments regarding data validity.
For questions regarding research reports, contact: Heather Choi at (916) 322-3893
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