Reassessment of Reassessment of Tropospheric Ozone due to Tropospheric Ozone due to

Fires/PollutionFires/Pollution

Stephan GallagherStephan Gallagher

MotivationMotivation

The contribution to the total tropospheric ozone of The contribution to the total tropospheric ozone of these sources can be accurately determined:these sources can be accurately determined: Boundary LayerBoundary Layer Regional Convection and Lightning (Gravity Wave)Regional Convection and Lightning (Gravity Wave) Stratosphere (Rossby Wave)Stratosphere (Rossby Wave)

However, there is a significant amount of ozone However, there is a significant amount of ozone unaccounted for, which is referred to as aged or unaccounted for, which is referred to as aged or advected ozoneadvected ozone Based on the budget formula, advected ozone can be Based on the budget formula, advected ozone can be

thought of “everything else” after the aforementioned thought of “everything else” after the aforementioned sourcessources

MotivationMotivation

Budget PlotBudget Plot Blue: ozone source is advected or “Other”Blue: ozone source is advected or “Other”

OverviewOverview This study was done to try to find a specific This study was done to try to find a specific

contribution, in the form of fires/pollution, to this contribution, in the form of fires/pollution, to this significant portion of the ozone budgetsignificant portion of the ozone budget

Using ARCIONS ozone budgets, the following Using ARCIONS ozone budgets, the following specific contributions to the advected ozone were specific contributions to the advected ozone were determined:determined: Asian Pollution/California FiresAsian Pollution/California Fires Siberian FiresSiberian Fires Canadian FiresCanadian Fires

In the end, a new ozone budget was able to be In the end, a new ozone budget was able to be computed that accounted specifically for the computed that accounted specifically for the contribution of fires/pollutioncontribution of fires/pollution

ARCIONS LocationsARCIONS Locations

Boulder, CO (13)Boulder, CO (13) Bratt’s Lake, SK (11)Bratt’s Lake, SK (11) Kelowna, BC (10)Kelowna, BC (10) Stony Plain, AB (9)Stony Plain, AB (9) Whitehorse, YK (6)Whitehorse, YK (6) Yellowknife, NT (7)Yellowknife, NT (7)

Methods: Back Trajectory LayersMethods: Back Trajectory Layers

Layers were determinedLayers were determined Using Hysplit back trajectories, 3 distinct, average layers Using Hysplit back trajectories, 3 distinct, average layers

were determinedwere determined From the boundary layer to the tropopause, back trajectories From the boundary layer to the tropopause, back trajectories

in increments of 1 km were run to indicate different levels in increments of 1 km were run to indicate different levels (based on directional changes)(based on directional changes)

Provided a fairly complete representation of the movement of Provided a fairly complete representation of the movement of air parcels air parcels throughout the entire tropospheric columnthroughout the entire tropospheric column, prior to , prior to reaching the locationreaching the location

If no distinct directional changes were apparent in the back If no distinct directional changes were apparent in the back trajectories, average, standard levels were assumedtrajectories, average, standard levels were assumed

Low: Boundary layer to ~5 kmLow: Boundary layer to ~5 km Middle: ~5 km to ~8 kmMiddle: ~5 km to ~8 km Upper: ~8 km to TropopauseUpper: ~8 km to Tropopause

Standard levels were used based on the average level Standard levels were used based on the average level heights for each location and allowed data from all days to heights for each location and allowed data from all days to be usedbe used

Methods: Back Trajectory LayersMethods: Back Trajectory Layers

Example from Yellowknife, NT (July 2, levels: red: 4 km, Example from Yellowknife, NT (July 2, levels: red: 4 km, blue: 7 km, green: 10km) of three levels as each blue: 7 km, green: 10km) of three levels as each direction of back trajectories are substantially different direction of back trajectories are substantially different

Methods: Back Trajectory LayersMethods: Back Trajectory Layers

Back Trajectory Data Summary

  Average Levels (km) Standard Levels Used

Site Average Boundary Layer (km) Low Middle Upper Average Tropopause (km) Low Max Middle Max

Boulder 2.2 2.2-4.58 4.59-8.58 8.59-14.0 14.0 2 7

Bratt's Lake 1.9 1.9-4.05 4.06-7.36 7.37-10.9 10.9 3 7

Kelowna 2.9 2.9-5.19 5.20-8.04 8.05-11.7 11.7 6 11

Stony Plain 2.5 2.5-4.57 4.58-7.71 7.72-11.3 11.3 4 8

Whitehorse 2.2 2.2-4.84 4.85-8.20 8.21-10.9 10.9 4 7

Yellowknife 2.0 2.0-4.87 4.88-7.80 7.81-10.6 10.6 6 7

Summary of layer data at each locationSummary of layer data at each location

Methods: Fires/Pollution ContributionMethods: Fires/Pollution Contribution

The contribution of fires/pollution to ozone:The contribution of fires/pollution to ozone: Determine if any of the 3 back trajectory levels pass Determine if any of the 3 back trajectory levels pass

over:over: Asian Pollution: a major Asian city (ex: Beijing, Tokyo, Hong Asian Pollution: a major Asian city (ex: Beijing, Tokyo, Hong

Kong)Kong) California fires: any fire in CaliforniaCalifornia fires: any fire in California Siberian Fires: any fire in Siberia (primarily eastern Russia)Siberian Fires: any fire in Siberia (primarily eastern Russia) Canadian Fires: any fire in CanadaCanadian Fires: any fire in Canada

The location of fires (across all categories) was The location of fires (across all categories) was determined using daily interactive maps from the Fire determined using daily interactive maps from the Fire Information for Resource Management System (FIRMS)Information for Resource Management System (FIRMS)

All back trajectories were run for up to 6 days of data All back trajectories were run for up to 6 days of data

Methods: Asian Pollution ContributionMethods: Asian Pollution Contribution

Example of a back trajectory from Kelowna, BC Example of a back trajectory from Kelowna, BC (June 27, upper levels) that passes over a (June 27, upper levels) that passes over a polluted Asian city (Beijing) polluted Asian city (Beijing)

Beijing, China

Methods: California Fires ContributionMethods: California Fires Contribution

Example of back trajectory from Kelowna, BC (July Example of back trajectory from Kelowna, BC (July 4, middle levels) passing over California fires 4, middle levels) passing over California fires

Methods: Siberian Fires Methods: Siberian Fires ContributionContribution

Example of back trajectory passing over Siberian Example of back trajectory passing over Siberian fires from Whitehorse, YK (July 1, upper levels) fires from Whitehorse, YK (July 1, upper levels)

Methods: Canadian Fires Methods: Canadian Fires ContributionContribution

Example of back trajectory from Yellowknife, NT (July 9, Example of back trajectory from Yellowknife, NT (July 9, upper levels) passing over Canadian firesupper levels) passing over Canadian fires

Methods: Fires/Pollution ContributionMethods: Fires/Pollution ContributionFire/Pollution Source Contribution via Back Trajectory Passes over all

Locations

0.0%

5.0%

10.0%

15.0%

20.0%

25.0%

30.0%

35.0%

Boulder Bratt's Lake Kelowna Stony Plain Whitehorse Yellowknife

Locations

Pe

rce

nta

ge

Siberian Fires

Canadian Fires

Asian Pollution/CA Fires

Roughly 15 days worth of data at each location, Roughly 15 days worth of data at each location, at 3 levels, with 3 possible fire/pollution sources at 3 levels, with 3 possible fire/pollution sources

Methods: Level AssessmentMethods: Level Assessment

Ozone totals were computed individually for each of the Ozone totals were computed individually for each of the 3 average levels (as determined by back trajectories)3 average levels (as determined by back trajectories)

At each location, for every level with a fire/pollution At each location, for every level with a fire/pollution contribution, the amount of advected ozone for that day contribution, the amount of advected ozone for that day was compared to the average for that level for all dayswas compared to the average for that level for all days Yielded a percent fluctuation in advected ozone due to Yielded a percent fluctuation in advected ozone due to

fires/pollution for that day and when averaged over all days, a fires/pollution for that day and when averaged over all days, a percent fluctuation for advected ozone at each level, at each percent fluctuation for advected ozone at each level, at each locationlocation

With a percent fluctuation at each level, the percentage of ozone With a percent fluctuation at each level, the percentage of ozone due to fires/pollution could be determined at each locationdue to fires/pollution could be determined at each location

ResultsResults

Average % and Total Enhancement of Advected Ozone By Individual Fires/Pollution Sources at each Location

Location

Source Boulder Bratt's Lake Kelowna Stony Plain Whitehorse Yellowknife Overall Averages

Asian Pollution/California Fires 2.48% 12.36% 45.16% 8.69% 0.00% 0.00% 11.45%

Canadian Fires 0.00% 0.00% 0.00% 0.00% 0.00% 40.73% 6.79%

Siberian Fires 0.00% 70.51% 0.00% 0.00% 0.00% 0.00% 11.75%

Average % of Ozone Enhancement 0.83% 27.62% 15.05% 2.90% 0.00% 13.58% 10.00%

Total Enhancement (DU) 0.16 6.69 2.65 0.54 0.00 2.52 2.09

Average ozone enhancement due to fires/pollution: 2.09 DUAverage ozone enhancement due to fires/pollution: 2.09 DU Average percentage of Advected ozone enhancement due to Average percentage of Advected ozone enhancement due to

fires/pollution: 10.00%fires/pollution: 10.00% Site most affected: Bratt’s Lake: 27.62 % increaseSite most affected: Bratt’s Lake: 27.62 % increase Site least affected: Whitehorse: 0.00% changeSite least affected: Whitehorse: 0.00% change Source with largest impact: Siberian Fires: 11.75 % increaseSource with largest impact: Siberian Fires: 11.75 % increase

Results: New Budget PlotResults: New Budget PlotAverage Tropospheric Ozone Distribution Over all Locations: June-July 2008

0

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Boulder, CO Bratt's Lake, SK Kelowna, BC Stony Plain, AB Whitehorse, YK Yellowknife, NT

Locations

Ozo

ne

(D

U) Other

Fires/Pollution

Strat

RCL

BL

Budget Plot now includes Fires/Pollution contributionBudget Plot now includes Fires/Pollution contribution

ConclusionConclusion

Fires/Pollution do in fact impact ozone levels in an Fires/Pollution do in fact impact ozone levels in an appreciable wayappreciable way Allow us to have a better understanding of what makes Allow us to have a better understanding of what makes

up part of the advected ozone at a locationup part of the advected ozone at a location Fires/Pollution that exist globally can impact other Fires/Pollution that exist globally can impact other

continents continents Asian pollution and Siberian Fires both impact ozone Asian pollution and Siberian Fires both impact ozone

levels in western Canada and United Stateslevels in western Canada and United States Evident of a global issue to limit emissions of pollutants Evident of a global issue to limit emissions of pollutants

to guarantee better air quality across the globe (and not to guarantee better air quality across the globe (and not simply locally)simply locally)