A two-step approach for relating tapered element oscillating microbalance and dichotomous air sampler PM_2.5 measurements

Figures & data

Table 1. List of the NAPS collocated sites, number of measurement records, and measurement intervals

	No. of	Interval		TEOM (μg/m^3)		FRM (μg/m^3)		Temperature (°C)
Site	Records	From	To	Mean	SD	Mean	SD	Mean	SD
Fredricton NB	146	2005	2009	4.83	2.83	6.71	3.49	10.83	12.34
St Anicet QC	207	2005	2007	7.45	5.43	8.80	5.86	14.42	12.64
St Jean QC	194	2005	2007	7.04	5.16	9.49	6.65	14.95	11.75
Ottawa ON	508	2005	2009	6.50	4.56	8.23	5.29	11.89	12.44
Winsor ON	238	2005	2008	10.04	6.60	11.84	6.38	16.17	11.67
Toronto Elmcrest ON	344	2005	2008	8.43	6.27	10.77	6.89	12.46	11.59
Toronto Etona ON	153	2005	2008	8.71	5.17	10.26	5.62	14.26	11.36
Toronto Resource ON	526	2005	2008	8.18	5.88	10.54	6.72	14.10	11.05
Hamilton ON	202	2005	2009	8.61	5.46	11.35	6.36	12.08	11.77
Simcoe ON	304	2005	2008	8.69	6.68	10.69	6.88	14.01	11.31
Essex ON	256	2005	2008	7.39	5.50	11.25	7.03	9.25	11.25
Winnipeg MB	188	2005	2009	4.40	2.32	6.49	2.90	10.00	14.77
Saskatoon SK	132	2005	2009	4.00	1.86	6.64	2.85	11.39	13.23
Edmonton AB	108	2008	2008	5.36	3.17	8.43	5.36	9.30	13.54
Calgary AB	101	2006	2008	6.13	2.65	6.71	3.29	9.55	11.99
Van-Port Moody BC	181	2005	2009	5.90	3.05	6.94	3.10	14.21	6.55
Van-Burnaby BC	411	2005	2009	5.01	3.16	6.40	3.35	16.20	7.24
Prince George BC	147	2008	2009	7.57	6.50	9.82	7.42	10.70	11.42
Victoria BC	115	2005	2009	5.37	2.72	7.41	3.93	14.63	7.03
Van-Abbotsford	326	2005	2008	5.02	2.82	7.13	3.34	16.00	7.35
Quesnel BC	172	2007	2009	6.54	3.91	8.91	5.20	9.73	12.35
Williams Lake BC	85	2005	2006	7.32	4.44	9.60	5.37	8.84	10.64
Golden BC	136	2005	2007	6.91	3.89	10.50	7.19	19.10	7.11

Figure 1. Correlation between FRM/CM ratio and daily maximum temperature for Fredericton NB (site no. S40103).

Table 2. Comparison of the regression coefficients and coefficients of determination for the NAPS sites

		Coefficients
Site	Site ID	Intercept (b)	Slope (m)	Coefficient of Determination (R^2)	Coefficient of Determination (R^2) from Allen et al. (2010)
Fredericton NB	S40103	0.0651	0.7053	0.790	0.789
St Anicet QC	S54401	−0.4227	0.8910	0.883	0.883
St Jean QC	S55301	2.4648	0.4666	0.411	0.622
Ottawa ON	S60104	−0.2029	0.8094	0.852	0.842
Winsor ON	S60211	−0.4312	0.8586	0.779	0.779
Toronto Elmcrest ON	S60413	−0.5908	0.8312	0.859	0.845
Toronto Etona ON	S60429	−0.1823	0.8502	0.842	0.839
Toronto Resource ON	S60430	−0.1799	0.7911	0.783	0.755
Hamilton ON	S60512	−0.2120	0.7832	0.807	0.807
Simcoe ON	S62601	−1.0242	0.8901	0.883	0.883
Essex ON	S65601	−0.5851	0.7409	0.759	0.735
Winnipeg MB	S70119	0.9687	0.5395	0.532	0.499
Saskatoon SK	S80211	1.1442	0.4383	0.365	0.365
Edmonton AB	S90132	1.0511	0.5106	0.745	0.466
Calgary AB	S90227	1.8617	0.6675	0.559	0.225
Van-Port Moody BC	S100111	−0.4115	0.8978	0.837	0.837
Van-Burnaby BC	S100119	−0.7264	0.8974	0.868	0.846
Prince George BC	S100202	−0.1059	0.7754	0.818	0.818
Victoria BC	S100304	1.4213	0.5225	0.628	0.445
Van-Abbotsford	S101004	−0.2465	0.7365	0.664	0.645
Quesnel BC	S101701	0.0607	0.7390	0.895	0.895
Williams Lake BC	S102701	0.1630	0.7306	0.667	0.642
Golden BC	S103202	1.6186	0.5145	0.790	0.789

Note: The coefficients of determination (R²) for the same regression model presented in Allen (2010) are included.

Figure 2. Correlation between FRM/CM ratio and daily maximum temperature for Toronto Etona ON (site no. S60429).

Figure 3. Correlation between FRM/CM ratio and daily maximum temperature for Saskatoon SK (site no. S80211).

Figure 4. Correlation between FRM/CM ratio and daily maximum temperature for Edmonton AB (site no. S90132).

Figure 5. Correlation between FRM/CM ratio and daily maximum temperature for Quesnel BC (site no. S101701).

Table 3. Regression coefficients and coefficients of determination (R²) for the FRM/CM ratio calculated using the daily minimum and daily maximum temperatures

			Maximum Daily Temperature			Minimum Daily Temperature
Site	Site ID	Intercept	Slope	R^2	Intercept	Slope	R^2
Fredericton NB	S40103	1.6124	−0.0086	0.0294	1.5179	−0.0032	0.0035
St Anicet QC	S54401	1.4263	−0.0102	0.1262	1.3397	−0.0099	0.0998
St Jean QC	S55301	2.2792	−0.0425	0.1053	1.8855	−0.0396	0.0755
Ottawa ON	S60104	1.6744	−0.0162	0.0212	1.5144	−0.0131	0.0119
Winsor ON	S60211	1.7775	−0.0264	0.3740	1.5880	−0.0293	0.3615
Toronto Elmcrest ON	S60413	1.6918	−0.0221	0.2266	1.5163	−0.0228	0.1783
Toronto Etona ON	S60429	1.5654	−0.0086	0.3599	1.4131	−0.0213	0.3080
Toronto Resource ON	S60430	1.7273	−0.0194	0.0925	1.5659	−0.0194	0.0718
Hamilton ON	S60512	1.7962	−0.0266	0.2660	1.5638	−0.0267	0.2067
Simcoe ON	S62601	1.6600	−0.0191	0.1808	1.4900	−0.0193	0.1357
Essex ON	S65601	2.0450	−0.0337	0.2883	1.7616	−0.0369	0.2715
Winnipeg MB	S70119	1.9719	−0.0239	0.1415	1.7101	−0.0216	0.0989
Saskatoon SK	S80211	2.3781	−0.0388	0.1911	1.9025	−0.0432	0.1723
Edmonton AB	S90132	1.9471	−0.0234	0.1558	1.7191	−0.0277	0.1651
Calgary AB	S90227	1.2387	−0.0117	0.1897	1.0988	−0.0115	0.1359
Van-Port Moody BC	S100111	1.4218	−0.0100	0.0321	1.3313	−0.0066	0.0101
Van-Burnaby BC	S100119	1.6736	−0.0166	0.0624	1.4792	−0.0109	0.0130
Prince George BC	S100202	1.5450	−0.0089	0.0506	1.4460	−0.0060	0.0176
Victoria BC	S100304	1.7475	−0.0179	0.0658	1.6056	−0.0192	0.0440
Van-Abbotsford	S101004	2.4554	−0.0433	0.0643	1.9501	−0.0271	0.0131
Quesnel BC	S101701	1.5197	−0.0096	0.1001	1.4053	−0.0089	0.0582
Williams Lake BC	S102701	1.3508	0.0099	0.0246	1.4563	0.0154	0.0448
Golden BC	S103202	1.7782	−0.0216	0.1310	1.4472	−0.0137	0.0238

Note: This is the step 1 of the two-step approach.

Figure 6. Correlation between FRM and CM’ for Fredericton NB (site no. S40103).

Figure 7. Correlation between FRM and CM’ for Toronto Etona ON (site no. S60429).

Figure 8. Correlation between FRM and CM’ for Saskatoon SK (site no. S80211).

Figure 9. Correlation between FRM and CM’ for Edmonton AB (site no. S90132).

Figure 10. Correlation between FRM and CM’ for Quesnel QC (site no. S101701).

Table 4. Regression coefficients and coefficients of determination (R²) for the corrected CM using the daily maximum temperature

		Coefficients		R^2
Site	Site ID	Intercept (b)	Slope (m)	Before Transformation	After Transformation
Fredericton NB	S40103	1.066	0.767	0.789	0.910
St Anicet QC	S54401	0.567	0.890	0.882	0.938
St Jean QC	S55301	1.557	0.731	0.411	0.615
Ottawa ON	S60104	0.681	0.811	0.852	0.920
Winsor ON	S60211	0.515	0.929	0.779	0.899
Toronto Elmcrest ON	S60413	0.043	0.971	0.858	0.940
Toronto Etona ON	S60429	0.176	0.963	0.842	0.905
Toronto Resource ON	S60430	0.541	0.914	0.783	0.879
Hamilton ON	S60512	1.062	0.865	0.806	0.843
Simcoe ON	S62601	0.558	0.903	0.882	0.947
Essex ON	S65601	1.207	0.835	0.759	0.849
Winnipeg MB	S70119	1.719	0.655	0.531	0.624
Saskatoon SK	S80211	1.811	0.671	0.365	0.724
Edmonton AB	S90132	1.383	0.761	0.744	0.796
Calgary AB	S90227	0.149	0.962	0.559	0.754
Van-Port Moody BC	S100111	1.092	0.798	0.836	0.906
Van-Burnaby BC	S100119	1.115	0.757	0.868	0.912
Prince George BC	S100202	1.823	0.720	0.817	0.943
Victoria BC	S100304	0.701	0.867	0.627	0.757
Van-Abbotsford	S101004	1.755	0.661	0.663	0.760
Quesnel BC	S101701	0.986	0.837	0.895	0.940
Williams Lake BC	S102701	2.503	0.637	0.667	0.584
Golden BC	S103202	0.745	0.849	0.789	0.856

Note: This is the step 2 of the two-step approach.

Table 5. Regression coefficient and probability of significance (PS) for the combined two-step statistical approach

Site		Intercept		Slope for CM		Slope for T		Slope for CM×T
Number	Site	β0	PS	β1	PS	β2	PS	β3	PS	R^2
S40103	Fredricton NB	1.2578	0.0001	1.1819	0.0000	−0.0092	0.6099	−0.0033	0.2574	0.8710
S54401	St Anicet QC	0.6170	0.0480	1.2560	0.0000	0.0104	0.5148	−0.0099	0.0000	0.9273
S55301	St Jean QC	1.5823	0.1012	1.7480	0.0000	−0.0879	0.0723	−0.0244	0.0000	0.7077
S60104	Ottawa ON	0.4416	0.0113	1.3704	0.0000	0.0225	0.0205	−0.0143	0.0000	0.9331
S60211	Winsor ON	1.3195	0.0152	1.4956	0.0000	−0.0485	0.0705	−0.0164	0.0000	0.8726
S60413	Toronto Elmcrest ON	0.2129	0.4042	1.6101	0.0000	−0.0045	0.7601	−0.0202	0.0000	0.9467
S60429	Toronto Etona ON	−0.1401	0.7719	1.5685	0.0000	0.0039	0.8734	−0.0208	0.0000	0.9347
S60430	Toronto Resource ON	1.0126	0.0081	1.4625	0.0000	0.0083	0.6815	−0.0168	0.0000	0.8470
S60512	Hamilton ON	1.3824	0.0035	1.4446	0.0000	−0.0495	0.0604	−0.0136	0.0000	0.8946
S62601	Simcoe ON	1.2899	0.0000	1.3624	0.0000	−0.0355	0.0284	−0.0112	0.0000	0.9394
S65601	Essex ON	1.6271	0.0001	1.6259	0.0000	−0.0585	0.0274	−0.0205	0.0000	0.8701
S70119	Winnipeg MB	0.9854	0.0329	1.5089	0.0000	0.0232	0.3597	−0.0213	0.0000	0.6269
S80211	Saskatoon SK	2.8498	0.0000	1.2820	0.0000	−0.0180	0.5744	−0.0203	0.0030	0.5979
S90132	Edmonton AB	1.3548	0.0093	1.4819	0.0000	−0.0627	0.0967	−0.0056	0.2767	0.8094
S90227	Calgary AB	−0.3838	0.5544	1.2868	0.0000	0.0812	0.0493	−0.0232	0.0000	0.7175
S100111	Van-Port Moody BC	0.9371	0.0466	1.1051	0.0000	0.0313	0.3038	−0.0096	0.0136	0.8470
S100119	Van-Burnaby BC	1.1421	0.0000	1.1937	0.0000	0.0010	0.9444	−0.0087	0.0000	0.9098
S100202	Prince George BC	2.0689	0.0000	1.0973	0.0000	−0.0102	0.6490	−0.0068	0.0003	0.9418
S100304	Victoria BC	0.4445	0.6413	1.6221	0.0000	0.0260	0.6763	−0.0234	0.0109	0.7256
S101004	Van-Abbotsford	3.2347	0.0000	0.9561	0.0000	−0.0501	0.0679	−0.0004	0.9082	0.6751
S101701	Quesnel BC	1.3080	0.0000	1.2537	0.0000	−0.0219	0.1915	−0.0073	0.0000	0.9374
S102701	Williams Lake BC	2.0519	0.0205	0.9980	0.0000	0.0200	0.7725	−0.0019	0.7633	0.7427
S103202	Golden BC	0.2252	0.8242	1.6238	0.0000	0.0477	0.3620	−0.0279	0.0000	0.8439

Allen, G. 2010. Evaluation of Transformation Methods for Adjusting Historical TEOM Data in the NAPS Network. Prepared for the Analysis and Air Quality Section, Environment Canada, Ottawa, Ontario, Canada.

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