1、Changes in Concentration of Chemical Species using Back-Trajectory Analysis,Atlantas Emissions Affecting its surroundings,Focus,Determine whether emissions of certain chemical species (sulfate, elemental carbon, organic carbon) are advected by air flow from Atlanta to a rural location outside of Atl
2、anta (Yorkville) Use a back-trajectory program (developed by Tao Zeng) that utilizes MM5 input data to determine flow direction and changes with time Use chemical concentration data (provided by Dr. Wei Liu) to track concentration changes with time. Measurements in Atlanta are taken every day, and m
3、easurements in Yorkville are taken every three days.,Yorkville is located about 42 miles west-northwest of Atlanta.A flow from the southeast, east-southeast, or south-southeast will possibly allow Atlantas boundary layer chemical composition to affect Yorkvilles boundary layer chemical composition,S
4、O4 (Sulfate) Concentrations wrt Time,An example of a source of sulfate would be a power plant that burns coal. There could potentially be many sources of sulfate in the Surrounding area.The sulfate curve for Atlanta essentially the same as the sulfate curve for Yorkville.Back trajectory analysis may
5、 or may not explain Similarities.,Elemental Carbon changes wrt Time,Elemental carbon (EC) or Black carbon is a product of Fuel combustion.Atlanta is most likely the main source of EC in YorkvilleThe Atlanta curves and Yorkville curves are similar except a period around April 19 and 20.Back Trajector
6、y analysis will Most likely show if the source of EC in Yorkville is Atlanta EC emissions,Organic Carbon Concentration wrt Time,Organic carbon (OC) also is a product of fuel combustion.Atlanta is most likely the main source of OC in YorkvilleThe Atlanta curves and Yorkville curves are similar except
7、 a period around April 19 and 20.Back Trajectory analysis will Most likely show if the source of OC in Yorkville is Atlanta OC emissions,Back trajectory from April 9 at 00Z to April 11 at 00Z, 2000.This shows a shift in flow from the Northwest on April 9 to Southwest on April 10.This flow pattern co
8、uld Potential bring Atlanta Emissions to Yorkville,Back trajectory from April 10 at 00Z to April 12 at 00Z, 2000.This shows the Continued flow from The southwest Through the two days of April 10 and 11.This flow pattern would also potentially bring Atlanta emissions to Yorkville,Back trajectory from
9、 April 11 at 00Z to April 13 at 00Z, 2000This shows a shift of Flow from the Southwest on April 11 to Flow from the Northeast On April 12This could decrease Flow of emissions From Atlanta,Back trajectory from April 12 at 00Z to April 14 at 00Z, 2000This shows flow shifting From the west-northwest On
10、 April 12 to flow from The east-southeast on April 13This is an optimal flow Pattern for transport of Atlanta emissions To YorkvilleAtlanta and Yorkville Concentration curves have high concentration and are similar,Back trajectory from April 13 at 00Z to April 15 at 00Z, 2000This shows a general Pat
11、tern of flow from The southeast over the Days of April 13 and 14The optimal flow Pattern continues,Back trajectory from April 14 at 00Z to April 16 at 00Z, 2000This shows flow from The south by southeast On April 14 shifting to a Flow from the west on Towards April 16.The optimal flow pattern contin
12、ues and then slightly shifts,Back trajectory from April 15 at 00Z to April 17 at 00Z, 2000This shows a shift in Flow from the southeast On April 15 to flow from the southwest on April 16The optimal flow pattern Changes to a pattern That Is less favorable for flow Of emissions to Yorkville,Back traje
13、ctory from April 18 at 00Z to April 20 at 00Z, 2000This shows flow from the northeast over the days Of April 18 and 19The optimal flow pattern EndsThis is also the period when Atlanta and Yorkville OC And EC curves are not similar. OC and EC are still high in Atlanta, but are low in Yorkville,Back T
14、rajectory from April 19 at 00Z to April 21 at 00Z, 2000This shows a flow from The northwest on April 19 shifting to flow From the southwest on April 20.Optimal flow is not present Again until later in the monthOC and EC curves continue To have dissimilar characteristics,Back Trajectory from April 20
15、 at 00Z to April 22 at 00Z, 2000This shows flow from the West over the days of April 20 and 21,Back trajectory from April 28 at 00Z to April 30 at 00Z, 2000This shows flow from The northwest over the Days of April 28 and 29,Back Trajectory from April 29 at 00Z to May 5 at 00Z, 2000This shows a shift
16、 in Flow From the northwest on April 29 to flow from The east on April 30This flow could advect Emissions from Atlanta To Yorkville.The EC, OC, and sulfate Curves are similar and High in concentration,Preliminary Conclusions,EC and OC concentrations in Yorkville have a high possibility of being affe
17、cted by Atlanta emissions of theses chemical species. Back-Trajectories show high concentrations of OC and EC in Yorkville when flow is coming from the direction of Atlanta and low concentrations when flow is not coming from Atlanta. Sulfate concentrations are not as obviously affected by flow from Atlanta and may not be as sensitive to changes in Atlantas concentrations.,
