Investigating Atlanta Area Pollutant Trends

EAS 4480 – Data AnalysisJames Hite

Project Description Motivation: Census

Growth Monitoring Sites (5)

Sdekalb, Yorkville Bledsoe,Douglasville,

Conyers O3, CO, NOx, PM2.5 Previous Study on

VOCs

2000-2010 Population ChangeDeKalb: (43,737, 16.7%)Douglas: (16,847, 48.4%)Spaulding: (3,776, 16.4%)Rockdale: (8,190, 32.7%)Paulding: (22,856, 78.1%)Polk: -- (1,849, 14.6%)Haralson: -- (1,568, 12.3%)(expressed in housing units)

Trends in 1-hour averages

Initial Results Overall Negative Trends

- in line with VOC study Interesting points▪ Full positive: Conyers,

Sdklb O3

▪ 00-10: none/negative Motivation for

reanalysis (averaging) –diurnal cycle

Method=======LS Regression, Bootstrap resampling to determine 95% normal confidence interval

Example: Conyers O3

Trends in Daily/Monthly Avgs. Overall: increase in negative slopes Daily: Most retained negative trends

except Full&00-10 Conyers O3 – no trend Neg/none: Douglasville O3; pos/neg

Sdekalb O3 Monthly: Less noise less apparent

trends (in addition) Sdekalb O3: no full trend

(00-10 less) No-trends: Bledsoe O3, Sdkelab PMfine 00-10 Yorkville O3 no trend (full still

neg.)

Example Figures: Sdekalb O3

10-year loss: -7.20E-03 ppmv (daily) vs -6.77E-03 ppmv (monthly

Changes in Monthly O3

Linear Trends identified across indv. months Interesting results:

JFM, ND off-season (Bedsole): positive trends (other stations don’t really measure at this time) Conyers Apr. (+), Aug. (-) Sdekalb Jul./Aug. (-) Trends in Individual Monthly Averages: Ozone Slopes: ppmv/year

Month Bedsole Conyers Douglasville Sdekalb YorkvilleJan. 0.000539 no data no data no data no dataFeb. 0.001458 0.000724371 no data no data no dataMar. 0.000784 0.000445466 0.000697919 0.000455 0.000549Apr 0.0003 0.000570481 0.000572493 2.65E-05 0.000388May -0.00054 -0.000167528 -0.000340723 -0.00044 -0.00057Jun -8.43E-05 0.000590219 7.82E-05 -0.00032 -0.00039Jul -3.79E-05 -0.000521273 -0.000813447 -0.00113 -0.00087Aug -0.00066 -0.000965664 -0.000811305 -0.00126 -0.0008Sep 9.63E-05 -5.76E-05 0.0005018 -0.00038 0.000118Oct -0.00044 -2.96E-05 0.000127452 -0.00038 -0.00018Nov 0.000632 no data no data 0.001812 -0.00134Dec 0.000905 no data no data no data no data

Example Figures

Mar., Nov. off-season (Bedsole): positive trends Conyers : Aug. (-)Sdekalb : Aug. (-)

Note: other sites have similar slopes, did not pass resampling test for 95% confidence intervalInteresting: less urban areas have higher [March]

Rural v. Urban: Other Pollutants Yorkville / sdekalb pollutants: all significant

trends were negative PSD/CPSD Analysis

Bedsole plot: (Lombscargle method

on 1-hr avgs) … took ~20 minutes

Example: NOx

Rural v. Urban

Separate psd analysis @ each station

Cpsd analysis & phase lag Daily Nox cpsd shows a shared

weekly cycle with a lag of ~.5 day (yorksdekalb), would expect this since prevailing wind is easterly (coherence ~.7)

References

Data Source: http://georgiaair.org/amp/export.phpGeorgia Department of Natural Resources, Environmental Protection Division, Air Protection Branch Ambient Monitoring Program - Susan Zimmer-Dauphinee, Program Manager

Blanchard et. al. 2010 2009 Ambient Air Surveillance

Report