Where does the air polluti

the OTR come from and w

do we need to do to fix i

Tad Aburn, Director

Air and Radiation Management Administr

Presented at the OTC Annual Meeting

June 9 and 10, 2009
Why a Conceptual Model?

Driving Policy With Science Baltimore Haze 

 Bad Day – July 9, 

The first step in developing a new State Implementation Plan (SIP) Maryland

- The Canary

 Need a science-based vision of 

what it will take to further clean up Mar

yland’s air.

Maryland

- The Canary

in the Coal Mine for the 

OT

R

Good Day – August 1

y

 How much of the problem is local?

 How much is transported into 

Maryland from upwind states? Maryland from upwind states?

 What pollutants? What sources? How aggressive do we need to be 

with new local control programs?

 Who will we need help from?
Conclusions from this Presen



“Incoming

” ozone levels already violate

We Cannot Attain the New Ozone Standard

Without Significant, Timely Help from EPA

 Incoming ozone levels already violate

the new standard

 Science tells us that the upwind 

contribution to ozone in nonattainment

Nonattainmen

8-Hour Ozone S

contribution to ozone in nonattainment

areas in the Ozone Transport Region (OTR) can cause more than 50% of the problem

 We need to continue to do all we can to 

reduce local emissions.

 We need significant help from EPA to 

requi i d ti l ire aggress

ive an

d time

ly supe

r

-

regional emission reduction programs

 Across most of the East Power plants boilers cement kilns and Power plants, boilers, cement kilns and

multiple other source sectors that can further reduce NO

x and VOC emissions.

Graphic is courtesy of the U.S. EP
Progress in Cleaning Maryland

181

151 152 147 143 160

200

(ppb)

1-Hour Ozone 8-Hour Ozone

110 110 106 103 107 107 104

135 137

147 143 137

126 121

120

160

1-Hour Ozone 103 9

104 95 

80

1990 1992 1994 1996 1998 2000 2002 2004 2006 2008*

17 1

)

Annual Fine Particulate

41 41 42 41

Daily Fine Particu

1997 1999 2001 2003 20

17.1

15.8 15.9

14.5

15.6

16.2 15.9

1418

nual PM2.5 (ug/m3)41 41

39

41

10

2002 2003 2004 2005 2006 2007 2008*

Ann

2002 2003 2004 2005 2006 

*2008 data are preliminary.

What Have We Learned 

from All of This?
So...Where Does Our Air Pollution Come 

Four Distinct P

 Local emissions in Cities (nonattai

 Reducing local emissions is very, 

 Three distinct types of transport

Four Distinct P

 Three distinct types of transport

 Short range - City to city

 “Ground level” transport Washington to Baltimore, Ba

etc.

 Westerly, Long range (up-ove

 “Aloft” transport - 100s of m Generally from W or NW

 Southerly, Nocturnal Low Lev

 “Aloft” transport at night !!! 100s of miles SW to NE along the Atlantic SW to NE along the Atlantic
Two Significant New Findi

Recent research has identified two new conc

that significantly affect:

 Our understandin

g of the dail

y c

ycle of how ozone fo

builds up in Mid-Atlantic and Northeast cities and

 The emission reduction 

pg p ro

grams needed to 

provide f

air

These new areas are:

 The existence of an “Elevated Reservoir” of high oz

sitting above the Mid-Atlantic and Northeast areas dumornin

g y hours on bad ozone da

y

s

 The transport and build-up of ozone and ozone prec

night
The Elevated Ozone Reserv

 Every bd d 

b

a

d ozone 

da

morning hours, a larof ozone sits above 

and the Mi

d-Atlanti

waiting to mix down

 Ozone levels in the res

Ozone levels in the res

routinely reach 60 to 1

 In the morning, ozone 

surface are very low. Incoming Ozone August 2, 2005 (7:00 AM EDT) Beltsville MD

 Around 10:00 or 11

ozone in the reservo

d hf 

9000

12000

ight (ft)

Beltsville, MD

Good Moderate Unhealthy for 

Sensitive Groups Unhealthy

Residual Layer

from 1500 – 6000 ft

f 110 b

9000

12000

ight (ft)

Beltsville, MD

Good Moderate Unhealthy for 

Sensitive Groups Unhealthy

Residual Layer

from 1500 – 6000 ft

f 110 b

down to t

he sur

face 

degrades air quality

0

30006000

0 15 30 45 60 75 90 105

He

of 110 pp

b

Ozone-reduced 

surface layer

< 40 ppb

0

30006000

0 15 30 45 60 75 90 105

He

of 110 pp

b

Ozone-reduced 

surface layer

< 40 ppb

of 110 pp

b

Ozone-reduced 

surface layer

< 40 ppb

Ozone (ppb)

Source: Maryland Department of the Environment & Howard University
What Creates the Reservo

 Ozone created during the day is 

able to mix upward from the surface and vice versa.

 At night the earth cools and a 

“nocturnal inversion” is created several hundred meters above the 

surface.

 Ozone, created earlier in the day, 

is trapped above the inversion and is trapped above the inversion and 

moved to the north by nigh-time winds.

 Ozone below the inversion drops

Ozone below the inversion drops

to very low levels. 

Source: S
Measuring the Elevated Rese

The elevated reservoir ca

l i

High Elevation

- a

lmost every morn

ing -

looking at elevated monitground-level monitors - o

High Elevation

Monitors

Piney Run, MD

M th di t Hill PA

A p p a l a c h i a n s Hagerstown

M

eth

odist Hill, PA

Shenandoah NP, VA

Near-Sea Level

Monitors

Ba

Source: Maryland Department of the Environment
Typical Day/Night Ozone Cy
Back in 1990’s
Same Signal – Philly – 19
Same Signal – MD - 199
Same Signal – Philly - 19
Still Happening in 2000’
Same Signal – Philly 200
Same Signal – MD - 200
Same Signal – Philly - 20
Similar Signal – New Hamp

Diurnal Ozone Concentrations 2004-2008

Mt. Washington Summit versus Camp Dodge Base

Based on Days with Maximum 8-Hour Averages >=60ppb on the Summit 

60

This every 8hr >day's both 

5060

PB)

3040

ur Concentration (P 

1020

Average 1-Ho

0

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

Hour
Same Signal – Fine Particles

J l 28 2007

LIDAR Image

articlesSa

J

u

ly 28, 2007

More pa

Aerosols

Aloft Clear

Inversion 

Breaks

particles

Aloft

Mix with

Clear

Less 

Mix with

p

Local 

Pollutants

Source: SSEC at Univ

5AM 8AM 11AM 2PM 

Source: The Smog Blog (UMBC)
Who’s Filling the Reserv

 What’s over MD 

started off in Ohio Carolina on Mond

Aircraft Data – All Morning Ozone Profiles

(1996 – 2004)

 MD’s pollution 

to New Jersey York.

 New York’s po

to New Englan

 P lt 

Power p

lan

ts, cars, 

other sources are alto the elevated pollu

 ill d i h 

Median Ozone in ppb

Fill

e

d w

i

t

h ozone a

) precursors.

Courtesy of Jennifer Hains

University of Maryland
The Three Different Types of Tra

1997 8-hr ozone exceedance days hr ozone exceedance days

(2003-2007)

96 days or appx. 19 days/year

Westerly Transport

Source: Maryland Department of the Environment
How Much Comes From Out of 

 Prior to the NOx SIP 

we measured ozone 

parts per billion parts per billion (pp

(pp

into Maryland , primWest.

 After the NO

x SIP C

measure ozone aroufloating into the StatSouth, West, and N

 Reminder: 2008 8-H

Standard is Standard is 75 ppb. MDE works in partnership with local 

universities (UMD at College Park, UMBC, and Howard University) to measure and analyze pollution being transported into Maryland.
Baltimore: How Much is Trans

 Varies with changes in 

meteorology but best guess is 

something like

1997 8-hr ozone exceed

hr ozone exceed

(2003-2007)

96 days or appx. 19 d

something like

 30 to 40% Westerly transport 10 to 20% City-to-City 

“l l” t t “local”

transpor

t

 10 to 20% Night-time, 

southerly NLLJ transport

 10 to 20% local

 Local controls on local 

emissions can onl

y address this 

last 10 to 20%. Source: Maryland Department of the Environment
Classic Mid-Atlantic Ozone We
Westerly Transport
Westerly Transport - “Up ... Over ... 

During the heating of the day, pollutants mix u

pward.

Air pollutants get picked up and carried by the upper level winds

Pmsaca

p OVER

UP

SO2

PM

Hg

NOx

VOC

NH

Pollution 

Sources
Fingerprinting Westerly Tra

What Does the Data Tell us About Its Origin?

DOES NOT

CORRELATE

WELL WITH CO

* NOT CARS

*

HIGH OZONE

ALOFT NOT CARS

CORRELATES WITH CORRECORRELATES WITH

HIGH “AGED NOX”

* IT’S OLD * 

WI

* PR

POWE

Graphics are courtesy of UMD at College Park.
Reducing Westerly Transpo

55.5%

of Units

22.3%

of Units

77 229

244 250 25

8090 

Number of UnitsCumulative Total Units

8-Hour Ozone

110 110 106 103 107 107 104

p p b )

140

50

178

191

199

6070

BY 2011, ABOUT 5

TO 70 PERCENT 

OF THE COAL 

FIRED CAPACITY

106 103

91 94

104

95 93 91

8 -H our O z one (p 100 50

30

128

304050

77.8% of Units Installed

between 2003-2007 Scheduled Startup U

FIRED CAPACITY

IN THE EAST 

WILL BE 

CONTROLLED BY 

SCRS

1997 1999 2001 2003 2005 2007

8

60

2 1 2

5

18

23

13

8

15

6

2

28

51

1020

30

2 1 2

2

2

3

5 10

0

1995 1997 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 

Phase I

Minimal SCR Units

Phase II

Minimal SCR Units Large Number of SCR Units Installed

Expect Minimal NOx

Reductions

Large Number of SCR Units Installed

Expect SIGNIFIANT NOx Reductions

Especially after 2003-2004

Air Quality

should decrease dramatically Data courtesy of The Institute of Clean Air Companies (ICAC).
Westerly Transport - Lessons Lea

 Ozone has been reduced 

dramatically as super-regional power plant NOx controls have been 

installe

d

 About 50 to 70 percent of the coal 

fi d it th E t h dd d fire

d capacity n the 

Eas

t

has add

e

d

SCR controls

 About 30 to 50 percent has About 30 to 50 percent has not

added SCR controls 

 Is there an

y reason to believe that 

more NOx reductions would not lead to lower ozone?
City-to-City “Local” Trans

 Surface winds are typically from the southwest to the northeast Surface winds are typically from the southwest to the northeast.

 The morning pollution in Washington stays at ground level and floa

become part of the afternoon pollution in Baltimore.

 Pollution from Central/Northern VA 

ֲ DC 

ֲ Baltimore 

ֲ Philadelph

 Emissions from cars, area sources and stationary sources all contribu
Southerly Transport at N

Th N t l L L l J t (NLLJ

Winds ~ 1000 Feet Above Surface

 Fast-moving, narrow “ri

typically around 1000 fe

f

The 

Noc

turna

l

Low 

Leve

l

J

e

t (NLLJ

sur

face

 In the Mid-Atlantic, typi

during the night between and the Atlantic Ocean.

 Wind speeds can reac

more.

 Stretches from NC to 

further up the east co

MDE

further up the east co

 Seen during most, Mid-A

time air pollution events

 Some form of NLLJ 

During the heating of the day, pollutants mix upward.

Air pollutants get picked up and carried by the upper level winds

Pollutants can mix down the same way they came up OVER

DOWN

code oran

ge or red da

 Recent findings indicate

 Presence of a NLLJ i

B lti i 

NOx

VOC

SO2

PM

Hg

UP

B

altimore maximum 

 Ozone concentration

have been measured 

Animation is courtesy of The COMET Program <http://www.meted.ucar.edu/>.

New Hampshire Pollution 

Sources
Measuring the NLLJ

Wind Speed and Wind Direction

Beltsville, MD on September 6 Beltsville, MD on September 6 – 8, 2007 8, 2007

13000

t)

35 mph for 8 hours is about 280 miles

What does this graph tell us?

- Wind direction- Wind speed

September 7th

8 PM – 9 AM

September 8

7 PM – 8 AM

September 7th

Winds from the southwest

at about 25 - 35 mph

September 8

Winds from the sou

at about 25 - 35 m

8000

Height (ftWind speed - Straight up_

35001000

Nocturnal Inversion up to 1000 ft

NLLJ NLLJ

Noon 6 PM Midnight 6 AM Noon 6 PM Midnight 

Sept 6, 2007 Sept 7, 2007 Sept 8, 2007

Nocturnal Inversion up to 1000 ft

Sou ce: y d ep e o e v o e & S rce: Mar

ylan

d Department of the En

vironment 

& MADIS
Measuring Ozone Transport in the 

H d U i it l h d 4 d J l 12 13 2008 Th 10 3

Jul 12 | Jul 13, 2008

2 30 AM

Howar

d

U

niversity launc

h

e

d

4 ozoneson

des on 

J

uly 12-13, 2008. The 10:3

(Saturday, July 12th) and 2:30 AM (Sunday, July 13th) occurred during a No

Low Level Jet (NLLJ) event, as captured by MDE’s upper-air Radar Wind P

10:30 PM

2:30 AM

d-Night 

EDT) Ozone Spike at

MidSpike at

(E

NLLJ 

Core

NLLJ

(22+ mph for 14+ hour

Î Air Traveled 300+ mi

2:00

PM

5:00

PM

8:00

PM

11:00

PM

2:00

AM

5:00

AM

8:00

AM

12-Jul

2008

Time (EDT)
How Big is the NLLJ?

MM5 M d l R MM5

M

o

d

e

l

Run 

– Hi h t Wi d S d i R 

Hi

g

hes

t Wi

n

d

Spee

ds 

in 

R

9:00 PM 11:00 PM 

03:00 AM 05:00 AM 

Graphics are courtesy of UMD at College Park.
When Transport Patterns Co

 Westerly, local and southerly/NLLJ transport converge on 

Atlantic area.

 Sea and bay breezes act as a barrier or wall and funnel oz

other air pollutants up the Northeast Corridor.
Driving Policy With Scien

 Ai ll ti i li t 

Air poll

ution 

is complica

t

 On any given day, Marylan

problem can be blamed on

 Local emissions

So What Have We Learned?

 Westerly Transport Southerly transport All of the above

 Th NO eSIP C ll d th 

x SIP

C

all an

d other 

programs have reduced ozondramatically over the past 10 

 The regional NO

x reduction 

of the 1990s really really wof the 1990s really, really w

 The 1990 Clean Air Act ma

much on local emission red

 We will need significant add

C t lM d l or super-regional control p

reduce transport to attain thstandard.

Concep

tual M

o

d

el
A Two Part Control Strate

We must contiad 

opt aggress

control measureduce the loc

contribution

W ill d We will nee

d s

help to reduce trans

ported oz

ozone precurselevated reser
Local Versus Regional Contrib

 Work to adopt innovative, agg

control programs already beg



“Incoming

” ozone already ex

 Work to adopt innovative, agg

control programs already beg



“Incoming

” ozone already ex

Vertical Profile of Ozone

June 18, 2006 (3:10 AM EDT)

Beltsville, MD

d d U h lh h lh

 Incoming ozone already ex

ozone standard

 To reduce transported ozone i

reservoir we need hel

p from E

 Incoming ozone already ex

ozone standard

 To reduce transported ozone i

reservoir we need hel

p from E

9000

12000

t)

Good Moder

ate

Unhealthy 

for Sensitive 

Groups

Unhealth

y

p

NOx and VOC emissions from 

upwind source categories and source regions

 Th t l 

p

NOx and VOC emissions from 

upwind source categories and source regions

 Th t l 

6000

Height (ft Elevated 

Reservoir 

2000 – 6000 ft

About 83 ppb 

 There are many con

tro

l progr

implemented in nonattainmenthe country that are cost-effecsense and proven control tech

 There are many con

tro

l progr

implemented in nonattainmenthe country that are cost-effecsense and proven control tech

0

3000

0 15 30 45 60 75 90 105

Ozone (ppb)

pp

at 3am

Source: Maryland Department of the Environment & Howard

 We need EPA’s help to level 

field

Source: Maryland Department of the Environment

& Howard

University
“Leveling the Playing Fie

 Examples of control programs that need 

to be implemented across most of the East to reduce transported ozone in the elevated reservoi

r

CURRENT 

PLAYING 

FIELD

 The next phase of NO

x and SO

x

reductions from power plants

 Industrial, Institutional and Commercial 

(ICI) boilers (NO (ICI) boilers (NO and SO

)

x and SO

x

)

 Cement kilns (NO

x and SO

x

)

 25 ton per year NO

x and VOC RACT 

( y Reasonabl

y Available Control 

Technology)

 OTC area source control measures 

(paints, consumer products, etc.)

 Mobile so rces Mobile so

urces

 Numerous other source sectors 

GENERALLY WHE

THE PLAYING FIE

SHOULD BE LEVE

TO REDUCE OZO

IN THE ELEVATEIN THE ELEVATE

RESERVOIR
Our Schedule

 2016

 Likely attainment date for m

states

 Summers 2013, 2014 and 201

 Clean air recorded b

y moni

 May 2013 

 Latest date for new state, re

nati l t l t 

tiona

l con

tro

l programs 

t

effective and generate redu

 2010 and 2011

 State, regional and nationa

adopted
Questions?

Tad Aburn Director Tad Aburn, Director

gaburn@mde.state.md.us

Maryland Department of the Environme

Air & Radiation Management Administra

1800 Washington Boulevard | Baltimore, MD 21230

410-537-3000 | TTY Users: 1-800-735-2258

www.mde.state.md.us

Martin O’Malley, Governor | Anthony G. Brown, Lt. Governor | Shari T. Wilson, Secretary