CMB_Demo - Atmospheric Dispersion Modeling Receptor Model...

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Unformatted text preview: Atmospheric Dispersion Modeling Receptor Model Chemical Mass Balance (CMB8.2) Hsing-Wang Li 9/13/11 03/29/2011 BLK 315 Web resources to download CMB 8.2 US EPA : ttp://www.epa.gov/ttn/scram/receptor_cmb.htm 9/13/11 Banner Page for EPA CMB8.2 YÂE 9/13/11 Input files for CMB 8.2 For each run of CMB, the model fits speciated data from a specified group of sources (sources) to corresponding data from a particular receptor (samples). (1). Source PRofile selection file: PR*.sel (2). Ambient Data (sample) selection file: AD*.sel 9/13/11 Launching EPA-CMB 8.2 YÂE 9/13/11 Select Input Files Screen ª_ ÐYÂ< Note that EPA-CMB8.2 will accept *.csv, *.dbf, and *.wks data formats for ambient sample (AD*) and source profile (PR*) files, which are the only input files required by the model. 9/13/11 Options 9/13/11 Options (1)Iteration Delta: This parameter sets the maximum number of iterations EPA-CMB8.2 will attempt to arrive at a solution. (Must be >0; no theoretical upper limit; default = 20) (2)Maximum Source Uncertainty: The maximum source uncertainty is a threshold expressed as a percentage of the total measured mass and is adjustable via the spinners (default = 20% ). (3)Minimum Source Projection: The minimum source projection is set to a default value of 0.95. 9/13/11 Options (4)Decimal Places Displayed: The default value is 5 and the maximum value is 6. (5)Units: The units used for reporting results may be changed via a pull-down menu. (6)Output File Format: The file format for spreadsheettype output is selected in the pull-down box. As discussed in Section 4.5, the default is ASCII (txt); commaseparated value (CSV) is also available. (7)Britt and Luecke: Checking this box applies the Britt and Luecke (1973) linear least squares solution that is explained by Watson et al. (1984) when applied to CMB calculations. 9/13/11 Options (8)Source Elimination. Checking this box eliminates negative source contributions from the calculation, one at a time. (9)Best Fit. Checking this box causes the program to cycle through the corresponding pairs (same array index) of fitting species and source profile arrays specified in the source and species selection input windows until the best composite. ª_ 9/13/11 ÐYÂ< Select Ambient Data Samples ª_ ÐYÂ< one or more samples may appear selected initially. Otherwise, individual samples are “tagged” by clicking in the respective fields under “SELECTED”. 9/13/11 View Grid YÂE 9/13/11 Select Fitting Species Fitting species are used in the calculation of source contribution estimates 9/13/11 Select Fitting Sources The user should select profiles that represent the emissions most likely to influence receptor concentrations. 9/13/11 View Grid ÂE 9/13/11 Calculation Results YÂE 9/13/11 Calculation Results (1)When Run is invoked, EPA-CMB8.2 performs the least-squares estimation of source contribution estimates and performance measures on the selected sample data using the designated fitting species and source profiles. (2)Also if more  fitting sources than fitting species ª_ ÐY < have been selected, a warning appears and the user is forced to reconfigure. 9/13/11 Main report ÂE 9/13/11 Main report In the Main report are several information blocks which present performance measures. (1)First are fitting statistics: r2, P2, percent mass explained, and degrees of freedom. (2)Next is a block that presents the most basic results from EPA-CMB8.2: source contribution estimates. ª _ Ð Y  < (3)For each source selected is presented a source contribution estimate (SCE) in userchosen units, standard errors, and values for T-stat. 9/13/11 Contributions by Species 9/13/11 Contributions by Species (1)Beyond the traditional apportionment results generated by EPA-CMB8.2, it is also of interest to analyze the way in which pollutant mass is distributed among sources by species_ Ð Y  < . ª (2)The report also indicates which sources are the major and minor contributors to each species. 9/13/11 Modified Pseudo-Inverse Normalized (MPIN) Matrix The MPIN matrix identifies which fitting species have the largest influence on the source contribution estimates from each profile 9/13/11 Source contribution estimates by CMB model to meet following items TSTAT >2; (2) Chi-Square <2; (3) R-Square between 0.8-1.0; (4) Percent Mass ranging from 80-120. (1) 9/13/11 Case Study for CMB 8.2 (1) 9/13/11 Case Study for CMB 8.2 (2) 9/13/11 Case Study for CMB 8.2 (3) 9/13/11 Thanks ! YÂE 9/13/11 ...
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