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Emissions Modeling Clearinghouse
Temporal Allocation

Another step of modeling inventory development is the temporal allocation of emissions. Because air quality modeling attempts to represent the actual physical and chemical processes as they occur over a specific duration of time, it is important that the temporal allocation of emissions be as accurate as possible. Temporal allocation can be thought of as an accounting of emissions variation over time. The simplest temporal allocation is for a steady-state emissions source that continually releases emissions at the same rate all the time. Under actual conditions, however, steady-state emission sources are quite rare. Instead, under actual conditions, emissions sources may operate only in the winter, not operate on Sundays, or their activity may peak during certain hours of the day. Temporal allocations allow emissions variability to be correctly modeled during the desired modeling periods. The desired modeling periods will vary depending upon the purpose of the inventory.

Related Temporal Allocation Files
Temporal Profile Usage Memorandum (4/29/2002)
This document outlines the usage of each of the temporal allocation files to estimate hourly from annual emissions.
(PDF 13K)

CAIR Platform Data
Temporal SMOKE CAIR Platform Data - SMOKE Format February 2005 (ZIP 248K)
Temporal Cross Reference File for CAIR Platform - MS Excel February 2005
(XLS 2.8M)
Temporal Profile - CAIR Platform - MS Excel February 2005
(XLS 760K)

Pre CAIR Data
Source Category Code / Temporal Allocation Cross Reference File (4/29/2002)
This file provides SCC to monthly, weekly, and diurnal temporal allocation profile matches.
(DBF 373K)
Monthly Profile File (4/29/2002)
This file provides the monthly profile code and associated monthly weighting factors.
(DBF 123K)
Weekly Profile File(12/14/2000)
This file provides the weekly profile code and associated day-of-week weighting factors.
(DBF 3K)
Diurnal Profile File (12/14/2000)
This file provides the diurnal profile code and associated hour-of-day weighting factors.
(DBF 10K)

| Office of Air Quality Planning & Standards | Technology Transfer Network |
| Clearinghouse for Inventories & Emissions Factors |


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