Tropospheric Ozone Tropospheric Ozone Days and Atmospheric Days and Atmospheric Air Mass Relationships Air Mass Relationships in Charlotte, NC and in Charlotte, NC and

Columbia, SCColumbia, SC

Casey G. ZuzakCasey G. ZuzakUniversity of South CarolinaUniversity of South Carolina

Department of GeographyDepartment of Geography

3 April 20093 April 2009

OutlineOutline

Background – Ozone/City Background – Ozone/City Selection/Air MassSelection/Air Mass

DataData Research Questions and FindingsResearch Questions and Findings ConclusionsConclusions QuestionsQuestions

Why Do We Study Ozone?Why Do We Study Ozone?

Can cause serious health effects on Can cause serious health effects on Humans and PlantsHumans and Plants Human Effects – 2008 Beijing Summer Human Effects – 2008 Beijing Summer

OlympicsOlympics Respiratory System (Asthma and Emphysema)Respiratory System (Asthma and Emphysema) EyesEyes Mucous Membranes in the Nose and ThroatMucous Membranes in the Nose and Throat

Plant EffectsPlant Effects Reduction in Crop ProductionReduction in Crop Production Damage to Leafs and their ProcessesDamage to Leafs and their Processes Major source of non-drought related crop Major source of non-drought related crop

damagedamage

What is OzoneWhat is Ozone It is the Allotrope of Oxygen (OIt is the Allotrope of Oxygen (O33))

Discovered in the middle 19Discovered in the middle 19thth century century Natural in the Upper Atmosphere, but harmful at Natural in the Upper Atmosphere, but harmful at

the surfacethe surface Produced when the two Produced when the two Primary PollutantsPrimary Pollutants, ,

Nitrogen Oxides and Volatile Organic Material Nitrogen Oxides and Volatile Organic Material combine to change in sunlight through a series combine to change in sunlight through a series of photochemical reactions to create of photochemical reactions to create Secondary PollutantsSecondary Pollutants Secondary PollutantsSecondary Pollutants are what causes the ground are what causes the ground

level ozone pollutionlevel ozone pollution Other hazardous byproduct – Peroxyacetyl Nitrate Other hazardous byproduct – Peroxyacetyl Nitrate

(PAN)(PAN)

How Ozone is FormedHow Ozone is FormedNO2 + sunlight NO + O

This free oxygen radical then reacts with O2 (how oxygen is naturally found)

O + O2 O3

Ozone is then consumed by nitric oxide to produce nitrogen dioxide and oxygen

O3 + NO NO2 + O2

Harmful products such as PAN are produced when nitrogen dioxide is combined with hydrocarbons

NO2 + hydrocarbons PAN’s

The main source of hydrocarbons are VOC’s, and when the organic or inorganic oxygenated compounds react with nitric oxide, they produce more

nitrogen dioxide

NO + Oxygenated Compounds NO2 + Other products

Normally, ozone is consumed, but the when the VOC are present this allows for the chemical reactions to continue

Charlotte, NC – Arrowood Charlotte, NC – Arrowood StationStation

PopulationPopulation 671,558 City671,558 City 2,491,650 CSA2,491,650 CSA

Estimated 24.3 Estimated 24.3 minute commute minute commute timetime

Weather Weather Observations from Observations from Charlotte Douglas Charlotte Douglas International AirportInternational Airport

Weather

Station

Ozone

Station

Downtown

2 mi

2 km

Columbia, SC – Congaree Flats Columbia, SC – Congaree Flats StationStation

PopulationPopulation 124,818 City124,818 City 753,663 CSA753,663 CSA

Estimated 17.3 Estimated 17.3 minute commute minute commute timetime

Weather Weather Observations from Observations from Columbia Columbia Metropolitan AirportMetropolitan Airport

Weather

Station

Downtown

Ozone

Station2 mi

2 km

Air Mass and OzoneAir Mass and Ozone

Meteorological Meteorological FactorsFactors Cloud CoverCloud Cover TemperatureTemperature Dew PointDew Point Wind SpeedWind Speed Wind DirectionWind Direction

Seasonal FactorsSeasonal Factors Summer and Spring Summer and Spring

have highesthave highest surface surface ozone concentrationsozone concentrations

Orographic Orographic FactorsFactors Valleys versus Valleys versus

MountainsMountains

Air Mass EffectsAir Mass Effects Anticyclones are most Anticyclones are most

associated with high associated with high ozone concentrationsozone concentrations

Higher TemperaturesHigher Temperatures Light WindsLight Winds Little CloudsLittle Clouds

Spatial Synoptic Spatial Synoptic Classification Classification

Based solely on surface based Based solely on surface based observations from individual stationsobservations from individual stations

Model that looks at Temperature, Model that looks at Temperature, Dew Point, Wind, Pressure, and Dew Point, Wind, Pressure, and Cloud CoverCloud Cover

Weather Type Classification for over Weather Type Classification for over 400 stations in the US and Europe400 stations in the US and Europe

Dr. Scott Sheridan Classification Dr. Scott Sheridan Classification SystemSystem

ClassClass GroupGroup DescriptionDescription

DPDP 11 cP Classic air mass…Cold, Clear, and DrycP Classic air mass…Cold, Clear, and Dry

DMDM 22 Moderate and Dry…modified cPModerate and Dry…modified cP

DTDT 33 cT Classic air mass…Hot and DrycT Classic air mass…Hot and Dry

MPMP 44 mP Classic air mass…Cloudy, Humid, CoolmP Classic air mass…Cloudy, Humid, Cool

MMMM 55 Warmer and more Humid than MPWarmer and more Humid than MP

MTMT 66 mT Classic air mass…Hot and HumidmT Classic air mass…Hot and Humid

MT+MT+ 77 Class for MT where mT is usually seenClass for MT where mT is usually seen

MT+MT+++

88 Oppressive MTOppressive MT

TRTR 99 Transitional throughout the dayTransitional throughout the day

DataData

1 January 2002 to 31 October 20071 January 2002 to 31 October 2007 Daily Maximum 8-hour Ozone Daily Maximum 8-hour Ozone

concentration calculated by the EPA concentration calculated by the EPA standersstanders It is the average of the measured hourly It is the average of the measured hourly

ozone concentrations over an 8-hour ozone concentrations over an 8-hour periodperiod

Air Mass data from the Spatial Air Mass data from the Spatial Synoptic Classification Synoptic Classification

Research QuestionsResearch Questions

How much does population effect How much does population effect tropospheric ozone?tropospheric ozone?

What Air Masses are the most What Air Masses are the most prevalent in high ozone days?prevalent in high ozone days?

Are there differences in air masses Are there differences in air masses between high ozone days between between high ozone days between Charlotte, NC and Columbia, SCCharlotte, NC and Columbia, SC

How Much Does Population How Much Does Population Effect OzoneEffect Ozone

The base population used was the The base population used was the 2006 US Census estimate2006 US Census estimate

The amount of ozone each person The amount of ozone each person was ‘responsible’ for was calculatedwas ‘responsible’ for was calculated

Then, the ozone which represented Then, the ozone which represented each person was then adjusted by each person was then adjusted by the difference in population between the difference in population between the citiesthe cities

Base Population for 2006Base Population for 2006

Ozone per PersonOzone per Person

Adjusted Ozone per Adjusted Ozone per PersonPerson

What Air Masses are Most What Air Masses are Most Prevalent During the Highest Prevalent During the Highest

Ozone DaysOzone Days Used a One-way Analysis of Variable Used a One-way Analysis of Variable

(ANOVA) test to determine which Air (ANOVA) test to determine which Air Masses favored days with the highest Masses favored days with the highest amount of ozoneamount of ozone The critical level of ozone was set at 80 The critical level of ozone was set at 80

ppb, and this is the level that the EPA has ppb, and this is the level that the EPA has determined that its harmful effects would determined that its harmful effects would be felt on most humansbe felt on most humans

Air Masses were determined by the Air Masses were determined by the Synoptic Classification System and is Synoptic Classification System and is broken down into 8 categoriesbroken down into 8 categories Transition days were excludedTransition days were excluded

Charlotte, NC Ozone Charlotte, NC Ozone DistributionDistributionDistribution of Ozone for Charlotte, NC

Distribution of Surface Ozone over the SSC Weather Types – Charlotte, NC

Results of ANOVA - CLTResults of ANOVA - CLT

Distribution of Ozone for Columbia, SC

Columbia, SC Ozone Columbia, SC Ozone DistributionDistribution

Distribution of Surface Ozone over the SSC Weather Types – Columbia, SC

Results of ANOVA - CAEResults of ANOVA - CAE

ConclusionsConclusions

Population and OzonePopulation and Ozone Charlotte was expected to have a Charlotte was expected to have a

higher adjusted ozone…higher adjusted ozone… There was a difference between the city There was a difference between the city

populations versus the CSA population.populations versus the CSA population. Difference in ozone due to population is Difference in ozone due to population is

minimalminimal Future ResearchFuture Research

Examine the origin of the pollutantsExamine the origin of the pollutants

Conclusions IIConclusions II

Charlotte, NCCharlotte, NC High ozone days favor Weather ClassificationHigh ozone days favor Weather Classification

2 – Dry and Moderate2 – Dry and Moderate 3 – Dry and Hot3 – Dry and Hot 6 – Moist and Hot6 – Moist and Hot 7 – Extremely Moist and Hot7 – Extremely Moist and Hot

Columbia, SCColumbia, SC High ozone days favor the Weather ClassificationHigh ozone days favor the Weather Classification

3 – Dry and Hot3 – Dry and Hot A lower minimum value for ozone needs to be A lower minimum value for ozone needs to be

used in Columbiaused in Columbia

Questions?Questions?

Thank you for your Thank you for your attentionattention

Contact InformationContact InformationCasey Zuzak Casey Zuzak

zuzak@mailbox.sc.edu(803) 777-1699(803) 777-1699