29.01.2015 Views

CALPUFF and Postprocessors

CALPUFF and Postprocessors

CALPUFF and Postprocessors

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

F.6 Volume Source Emissions File with Arbitrarily Varying Emissions (VOLEMARB.DAT)<br />

The VOLEMARB.DAT file contains volume source data for sources with detailed, arbitrarily varying<br />

characteristics in time (as resolved by the 1-hour timestep of <strong>CALPUFF</strong>). Such volume sources may have<br />

time-varying emission rates, time-varying initial size, <strong>and</strong> time-varying location (they may move).<br />

VOLEMARB.DAT may be provided as either a sequential unformatted data file, or as a free-formatted<br />

ASCII data file (see Table F-28 for an example). Both of these use the same record structure consisting<br />

of four header records, followed by a set of data records containing time-invariant source information,<br />

<strong>and</strong> a set of records for the time-varying data. The time-invariant records contain a source identifier <strong>and</strong><br />

one user-defined flag for each source. The time varying emissions <strong>and</strong> source characterization data<br />

follow in subsequent records. One data record per source is required for each time period (e.g.,usually at<br />

hourly intervals).<br />

Multiple VOLEMARB.DAT files may be provided if groups of sources possess very different timevariability.<br />

For example, group 1 may require hourly data records for the entire simulation period, while<br />

group 2 may produce emissions for only a few weeks during the simulation. Using a second file for<br />

group 2 is more economical to prepare because a single data record can be used to prescribe a long period<br />

with no (or constant) emissions. Each such file must cover the entire modeling period, no source may<br />

appear in more than one file, <strong>and</strong> the species list must be identical among these files.<br />

The data in the VOLEMARB.DAT file are independent of the horizontal <strong>and</strong> vertical grid systems being<br />

used in the model. The horizontal coordinates are specified in terms of the meteorological grid projection<br />

(UTM or Lambert conformal coordinates). The vertical layers receiving the emissions of the source are<br />

based on the effective source height provided in the file.<br />

NOTE: There are substantial differences between the VOLEMARB.DAT file accepted by <strong>CALPUFF</strong><br />

(Version 5.4) <strong>and</strong> the VOLEM.DAT file accepted by earlier versions, so anyone familiar with the<br />

previous versions must be certain to review the contents of the next few pages! <strong>CALPUFF</strong> (5.4) will test<br />

the variables FNAME4 <strong>and</strong> VRS4 contained in the header of VOLEMARB.DAT to see that it identifies<br />

the correct file. Do not use an “old” VOLEM.DAT data file -- its format is no longer supported!<br />

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

F-152

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!