User's Guide to the Model Validation Kit - Harmonisation within ...

• Other examples are (these examples are not relevant in the case of
the Model Validation Kit): deposition may occur (a problem
relevant for the Prairie Gras experiment); a comparison of
observed near-centreline concentrations with predicted centerline
concentrations will not be fair (a problem related to an
implementation of the ASTM procedure).
Kincaid
Copenhagen
Pay attention to the following problems when using data from
Kincaid:
• The derived meteorological parameters, u *
, w *
, L and h pred
, should
be used with care or replaced.
• and are suspected to be unreliable.
w v
• It is recommended to use data with a quality indicator of 2 or 3
when analyzing model behaviour. One point is important to be
aware of: observations with QUAL=3 are biased in the sense that
they are never zero.
Pay attention to the following problems when using data from
Copenhagen:
• The tracer monitoring arcs were in general placed at distances
where the concentration was decreasing, i.e., the maximum was
closer to the source than any of the arcs.
• It is observed (Gryning and Tassone, 1994) that measured values
of are smaller than predictions by theory.
w
• The computed heat flux values may not be representative for a
greater area.
• When using the enclosed tools, pay attention to the format used
for time. E.g., 1417 means 14:17 – whereas Kincaid and
Indianapolis data are given for integer values of hour.
Lillestrøm
Pay attention to the following problems when using data from
Lillestrøm:
• The averaging period is only 15 minutes for the tracer data.
Concentration averages taken over longer time will tend to be
smaller than those registered, due to meandering.
• There was generally very light wind during the experiments.
• u *
was recorded as zero for the experiment with the highest
concentrations.
• In the data set, stability category has been computed based upon
the original method by Turner (1964). This is consistent with the
method used for the other data sets, but it does not very well take
account of Norwegian winter conditions with snow-covered
ground.
• Pay attention to the time format, which is a four-digit format like
that of Copenhagen (e.g. 1030 for 10:30).
Indianapolis
Pay attention to the following problems when using data from
Indianapolis:
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