Don Edwards, Carl Miller and Megan Meece
Department of Statistics
University of South Carolina
" Cyclicity in Water Quality Indicators at
National Estuarine Research Reserve (NERR) Sites "
The National Estuarine Research Reserve (NERR) is a network of 22 estuarine
reserves; each reserve has two monitoring sites. Five measures of water
quality (two dissolved oxygen measures, salinity, temperature, and depth)
have been collected at these 44 sites via autosamplers every half-hour, and
in some cases every fifteen minutes, since 1996. Our charge this year,
under support of the National Oceanic and Atmospheric Administration (NOAA),
has been to quantify and compare the periodicity in these 220 time series,
most of length exceeding 50,000 records. The work is still in progress. In
this seminar, we discuss interactive graphical tools we have developed for
examining the raw data series, and harmonic regression approaches to the
analysis. Besides the sheer size of the data sets, modeling these series
has been complicated by the presence of "deployment effects" (autosamplers
must be replaced approximately every two weeks; the data signal often
changes dramatically upon deployment of the new autosampler).
This work is also joint with Fred Holland and Elizabeth Wenner of the SC
Dept. of Natural Resources.
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