Table of Contents - The Atmospheric Studies Group at TRC

Section 9: CALPUFF
9.2.4 SURFACE.DAT and PROFILE.DAT
In addition to the capability to use three-dimensional wind fields generated by CALMET, a single-station
meteorological file can also be used by CALPUFF as its source of meteorological data. One form of
single station data accepted by CALPUFF is the CTDMPLUS (Perry et al., 1989) form. The standard
meteorological data files SURFACE.DAT and PROFILE.DAT can be used without modification,
although some CALPUFF options require additional meteorological variables that must be added as part
of an extended data record to SURFACE.DAT and PROFILE.DAT. Unlike the other two types of singlestation
data described above, the PROFILE.DAT file contains a vertical profile of data each hour, rather
than measurements made at a single height above ground. In this way, more detailed data from an on-site
tower with supporting remote measurement platforms (e.g., SODAR) can be used to define the vertical
structure of the flow. SURFACE.DAT contains calculated micrometeorological variables and the mixing
height. This extended SURFACE.DAT and PROFILE.DAT formats have been modified further to allow
sub-hourly time steps.
CALPUFF is normally run with a full three-dimensional wind field and temperature field, as well as twodimensional
fields of mixing heights and other meteorological variables (see CALMET.DAT in Section
9.2.1). However, in some near-field applications, when spatial variability of the meteorological fields
may not be significant (e.g., uniform terrain and land use), the single-station data file may be used. In
single station mode, CALPUFF assigns the single value of each variable read from the file to all grid
points, resulting in a spatially uniform gridded field. However, the model does not assume the
meteorological conditions are steady-state, which allows the important effects of causality to be simulated
even with the single-station meteorological data. For example, the time required for plume material to
reach a receptor is accounted for in the puff formulation, and curved trajectories and variable dispersion
and stability conditions over multiple hours of transport will result even when using the single-station
meteorological data. However, in general, the preferred mode for most applications of CALPUFF is to
use the spatially variable fields generated by CALMET.
SURFACE.DAT is created by the CTDMPLUS meteorological preprocessor, and the user should consult
the CTDMPLUS documentation to learn of its use and requirements. SURFACE.DAT includes hourly
mixing height, surface friction velocity, Monin-Obukhov length, and surface roughness. PROFILE.DAT
is created directly by the user. In standard form, it includes the hourly wind direction, wind speed (vector
and scalar), temperature, and turbulence ( w , and either v or ) at each measurement level. Note that
PROFILE.DAT uses wind direction in the usual meteorological convention (i.e., winds from the west
blowing toward the east has a value of 270°).
As an option, a non-standard, or extended version of PROFILE.DAT can also be used to provide the
temperature jump across an inversion above a mixed layer. This jump is used as a measure of the strength
of the temperature inversion when assessing the ability of a buoyant plume to penetrate the top of the
mixed layer (for the partial penetration option: MPARTL = 1). When a positive temperature difference is
provided at the end of the first record for the hour, CALPUFF will recognize it and use it. Otherwise,
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