CALPUFF and Postprocessors

CALPUFF and Postprocessors CALPUFF and Postprocessors

29.01.2015 Views

F.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. Unlike the other two types of single-station 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. 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 F.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 (F w , and either F v or F 2 ) 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 270E). 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, available temperature gradient data are used to estimate the inversion strength. MAR 2006 – CALPUFF F-111

Precipitation data, solar radiation, and relative humidity are not required in CTDMPLUS. They may be added to SURFACE.DAT in an exended data record. These fields may remain blank if they are not needed for the CALPUFF options selected. Precipitation is needed for wet deposition modeling, and the solar radiation and humidity data are needed for chemical transformation calculations. Other data associated with the SURFACE.DAT and PROFILE.DAT are provided in the CALPUFF.INP control file. These data include the land use type, elevation, and leaf area index of the modeling region, and two control variables (ISIGMAV and IMIXCTDM). The land use category is used to determine if urban or rural dispersion coefficients are appropriate when the Pasquill-Gifford/McElroy-Pooler dispersion coefficients are used during convective regimes. Also see the variables IURB1 and IURB2 in Input Group 12 of the control file. They define the range of land use categories that are to be considered urban (i.e., if the value of the land use category is between IURB1 and IURB2, inclusive, the modeling domain will be consider urban). Otherwise, it will be considered rural. The leaf area index is only used by the model if dry deposition velocities are being computed. The elevation is used to fill the 2-D terrain elevation array in CALPUFF that is normally filled from the CALMET file. This array is used to determine, through interpolation, the elevation of the gridded receptors generated by the model as an option. Because a single value is available here, all of the gridded receptors will be assigned this elevation. Receptor-specific elevations are assigned to each discrete receptor by the user in the CALPUFF control file (see Input Group 17). ISIGMAV indicates the form of the lateral turbulence data, and IMIXCTDM indicates which mixing height field (observed or calculated) is to be used. Sample SURFACE.DAT files are shown in Tables F-12(a) and F-12(b). Part (a) of the table shows the standard SURFACE.DAT data record. The extended data record is shown in Part (b) of the table. A sample PROFILE.DAT file is shown in Table F-13. Data records for SURFACE.DAT are described in Table F-14, and data records for PROFILE.DAT are described in Table F-15. Note that the year may be specified in either a YY (e.g., 94) or YYYY (e.g., 1994) format. The YY format is the original CTDM PLUS format. The PROFILE.DAT file may also be used in conjunction with the other meteorological data options in CALPUFF to provide measured turbulence data, or to provide the strength of the temperature inversion. When turbulence data are supplied, wind speeds should be provided in the file as well as the turbulence, so that conversions between F v and F 2 can be made. MAR 2006 – CALPUFF F-112

Precipitation data, solar radiation, <strong>and</strong> relative humidity are not required in CTDMPLUS. They may be<br />

added to SURFACE.DAT in an exended data record. These fields may remain blank if they are not<br />

needed for the <strong>CALPUFF</strong> options selected. Precipitation is needed for wet deposition modeling, <strong>and</strong> the<br />

solar radiation <strong>and</strong> humidity data are needed for chemical transformation calculations.<br />

Other data associated with the SURFACE.DAT <strong>and</strong> PROFILE.DAT are provided in the <strong>CALPUFF</strong>.INP<br />

control file. These data include the l<strong>and</strong> use type, elevation, <strong>and</strong> leaf area index of the modeling region,<br />

<strong>and</strong> two control variables (ISIGMAV <strong>and</strong> IMIXCTDM). The l<strong>and</strong> use category is used to determine if<br />

urban or rural dispersion coefficients are appropriate when the Pasquill-Gifford/McElroy-Pooler<br />

dispersion coefficients are used during convective regimes. Also see the variables IURB1 <strong>and</strong> IURB2 in<br />

Input Group 12 of the control file. They define the range of l<strong>and</strong> use categories that are to be considered<br />

urban (i.e., if the value of the l<strong>and</strong> use category is between IURB1 <strong>and</strong> IURB2, inclusive, the modeling<br />

domain will be consider urban). Otherwise, it will be considered rural. The leaf area index is only used<br />

by the model if dry deposition velocities are being computed. The elevation is used to fill the 2-D terrain<br />

elevation array in <strong>CALPUFF</strong> that is normally filled from the CALMET file. This array is used to<br />

determine, through interpolation, the elevation of the gridded receptors generated by the model as an<br />

option. Because a single value is available here, all of the gridded receptors will be assigned this<br />

elevation. Receptor-specific elevations are assigned to each discrete receptor by the user in the<br />

<strong>CALPUFF</strong> control file (see Input Group 17). ISIGMAV indicates the form of the lateral turbulence data,<br />

<strong>and</strong> IMIXCTDM indicates which mixing height field (observed or calculated) is to be used.<br />

Sample SURFACE.DAT files are shown in Tables F-12(a) <strong>and</strong> F-12(b). Part (a) of the table shows the<br />

st<strong>and</strong>ard SURFACE.DAT data record. The extended data record is shown in Part (b) of the table. A<br />

sample PROFILE.DAT file is shown in Table F-13. Data records for SURFACE.DAT are described in<br />

Table F-14, <strong>and</strong> data records for PROFILE.DAT are described in Table F-15. Note that the year may be<br />

specified in either a YY (e.g., 94) or YYYY (e.g., 1994) format. The YY format is the original CTDM<br />

PLUS format.<br />

The PROFILE.DAT file may also be used in conjunction with the other meteorological data options in<br />

<strong>CALPUFF</strong> to provide measured turbulence data, or to provide the strength of the temperature inversion.<br />

When turbulence data are supplied, wind speeds should be provided in the file as well as the turbulence,<br />

so that conversions between F v <strong>and</strong> F 2 can be made.<br />

MAR 2006 – <strong>CALPUFF</strong><br />

F-112

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