Generic Guidance and Optimum Model Settings for the CALPUFF ...

distributed at a particular location and they provide an excellent way to graphically present wind
speed data and wind direction data that has been collected over a long record of time.
Wind roses should be used to;
- Compare observation stations vs. winds at similar location from the 3D.DAT file,
to evaluate how well the prognostic model is doing.
Time Series Plotter –
- Evaluate the winds at upper air levels from the 3D.DAT file.
- Consider the flow at locations where no observations are present.
The time series plotter is a graphical method for depicting the time variability of meteorological
variables over an event, a day, a week, a month, season or a year. A time series is a sequence of
data points measured typically at successive times spaced at uniform time intervals. Time series
data have a natural temporal ordering, this makes time series analysis distinct from other common
data analysis problems in which there is no natural ordering of the observation. A time series
model will generally reflect the fact that observations close together in time will be more closely
related than observations further apart. In addition, time series make use of the natural one-way
ordering of time so that values for a given period will be expressed as deriving from some past
values rather than from future values.
TRC’s time series package allows the user to export, analyze and plot time series data into Excl
spreadsheets for easy viewing. The time series plotter module will extract meteorological time
series files from any of the following; CALPUFF.CON, 3D.DAT, CALMET.DAT, UP.DAT,
SURF.DAT. Access is also available to the following pollutants, SO2, CO, O3, H2S, NO, NO2,
NOx, NO3, PM10, PM2.5
Use Time Series plotter to show;
(a) Transgression of various meteorological parameters through time, by
season, month, and time of day
(b) Comparisons of long term mean vs. standard deviation vs. shorter period
Scatter Plots –
An option of TRC’s Time Series Package is Scatter Plots which is a tool for displaying two
variables for a set of data. The data is typically displayed as a collection of points, each having
the value of one variable determining the position on the horizontal axis and the value of the other
variable determining the position on the vertical axis.
The aim of a scatter plot is to suggest various kinds of correlations between variables with a
certain confidence interval. Correlations may be positive (rising), negative (falling), or null
44