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The Role of Ozone Transport in the Washington DC Area: 

The Role of Ozone Transport in the Washington DC Area Tad Aburn and Jeff Stehr, MDE and UMCP Transportation Planning Board February 18, 2004

Topics Covered : 

Topics Covered Transport 101- Where does Maryland’s poor air quality come from Background on Maryland’s air quality The role of “transported” pollution Transport 201 – The three types of transport Short-range transport Westerly transport Low level night time jets

Maryland’s Air Quality: 

Maryland’s Air Quality Ozone levels in Maryland are very high Fine particulate levels are high Air pollution contributes significantly to Bay pollution Regional haze and air toxics are also significant air pollution problems in Maryland

Slide4: 

Ozone Days Above the 1-hour Standard Source: MARAMA – 2002 Data # of Days

Fine ParticulatePercent of Monitors Above the Annual Standard : 

Fine Particulate Percent of Monitors Above the Annual Standard Source: MARAMA – 2001 Data Percent Monitors

Nitrogen Deposition to the Chesapeake Bay: 

Nitrogen Deposition to the Chesapeake Bay

A Quick Primer on How Ground Level Ozone is Formed: 

A Quick Primer on How Ground Level Ozone is Formed

Are Our Emissions Higher Than Other Areas?: 

Are Our Emissions Higher Than Other Areas? Source: U.S. EPA - 1999 figures

Are Our Emissions Higher Than Other States? : 

Are Our Emissions Higher Than Other States? Source: U.S. EPA - 1999 data tons per year

So Where Does It Come From? : 

So Where Does It Come From? Air pollution floating in from other states (called transport) is a significant contributor to our air pollution problems Maryland – the meteorologically challenged state MDE/UMCP Aircraft that measure “incoming” pollution Models that predict state by state contributions

Classic Ozone Weather in the Mid-Atlantic: 

Classic Ozone Weather in the Mid-Atlantic H Maryland sees its’ worst air pollution during the summer when a “Bermuda High” sets up over the Carolinas

Power Plant Emissions: 

Power Plant Emissions H Very large power plant emissions concentrated along the Ohio River valley Air aloft circulates clockwise around the high

How Much Comes From Out of State?: 

How Much Comes From Out of State? MDE works in partnership with the University of Maryland – College Park to measure and analyze pollution being transported into Maryland On our worst days we measure ozone at 110 parts per billion (ppb) floating into the state from the West The 1-hour standard is 125 ppb

Who is Contributing to Maryland’s Ozone Problem?: 

Who is Contributing to Maryland’s Ozone Problem? From EPA’s modeling to support the 22 state regional NOx reduction program called the “NOx SIP Call”

Are Local or Regional Reductions Better? : 

Are Local or Regional Reductions Better? In Maryland, our technical analyses show that on our worst days Local reductions are not very good at reducing local ozone. In other areas, like Atlanta, local reductions seem to be much more effective On days where our ozone is more “home grown” local reductions are more important Not our worst days, but we often see high ozone

Transport 201: 

Transport 201 The different types of transport The elevated ozone reservoir Short range transport Westerly transport Low level night time jets

Is It Just Power Plants or are There Other Types of Transport?: 

Is It Just Power Plants or are There Other Types of Transport? Maryland’s location places us at the “air pollution crossroads” when if comes to transport. Air pollution floats to us from the west and the south. Sometimes the air pollution we transport to the north actually “re-circulates” back to us. Power plants, cars and area sources are all involved in the transport process

Three Types of Transport That Affect Maryland: 

Three Types of Transport That Affect Maryland Short range VA to MD to PA, etc. Long range (synoptic scale) 100s of miles Generally from W or NW Low Level Night-time Jets 100s of miles SW to NE along the Atlantic All types of transport collect in an “elevated reservoir” of ozone

The Elevated Ozone Reservoir: 

The Elevated Ozone Reservoir Every bad ozone day, before any new ozone has been formed, a large reservoir of ozone sits above Maryland waiting to mix down. Ozone levels in the reservoir can routinely reach 80 to 100 ppb Early Morning Ozone Western Maryland Surface ozone is very low Ozone 2000 feet above the surface is very high

What Creates the Reservoir?: 

What Creates the Reservoir? 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 moved to the north by night-time jets. Ozone below the inversion drops to very low levels.

Ground Level Ozone at Night: 

This hourly ozone graph for a summer day near Frederick, Maryland shows ozone concentrations reaching a minimum in the early morning hours. Ground Level Ozone at Night

Regional Scale Ozone: 

Regional Scale Ozone In this case from July, 1999, the high elevation monitor at Methodist Hill in southern PA is above the nocturnal inversion. By late morning, mixing has brought all monitors to the common regional level.

Where Does the Reservoir Come From? : 

Where Does the Reservoir Come From? The elevated ozone reservoir above Maryland is a complex mix of pollution that originated in the west (primarily power plants) and the south (cars, area sources and stationary sources)

Short Range Transport: 

Short Range Transport Central VA to DC DC to Baltimore Baltimore to PA Ground level winds from the southwest to the northeast Emissions from cars, area sources and stationary sources float to the northeast and add to high ozone levels downwind

Westerly Transport: 

Westerly Transport On Maryland’s worst ozone days “westerly transport” plays a significant role in creating high ozone.

Classic Ozone Weather in the Mid-Atlantic: 

Classic Ozone Weather in the Mid-Atlantic H Maryland sees its’ worst air pollution during the summer when a “Bermuda High” sets up over the Carolinas

Power Plant Emissions: 

Power Plant Emissions H Very large power plant emissions concentrated along the Ohio River valley Air aloft circulates clockwise around the high

Westerly Transport – What Does the Data Tell us About Its Origin?: 

Westerly Transport – What Does the Data Tell us About Its Origin? CORRELATES WITH HIGH “AGED NOX” * IT’S OLD * CORRELATES WELL WITH SO2 * PROBABLY POWER PLANTS * DOES NOT CORRELATE WELL WITH CO * NOT CARS * HIGH OZONE ALOFT

Slide29: 

Low Level Jet The Low Level Jet Night time transport that moves air from NC to MD, MD to NJ, etc. The Jet is funneled northward by the Appalachians on the west and the Atlantic on the east Wind speeds up to 40 miles per hour can move pollution hundreds of miles overnight.

Slide30: 

Low Level Jet Recorded Above Fort Meade Maryland LLJ LLJ LLJ WHAT DOES THIS GRAPH TELL US? WIND SPEED AND DIRECTION ABOVE FT MEADE MD AUGUST 10 10 PM TO 8AM . . . AUGUST 11 10 PM TO 8AM. . . . AUGUST 12 10 PM TO 9AM am . . . NOCTURNAL INVERSION UP TO ABOUT 1000 FEET . AUGUST 10 WINDS FROM THE SOUTHWEST AT ABOUT 25 to 30 MPH 1000 FEET ABOVE THE SURFACE AUGUST 11 WINDS FROM THE SOUTHWEST AT ABOUT 30 to 40 MPH 1000 FEET ABOVE THE SURFACE AUGUST 12 WINDS FROM THE SOUTHWEST AT ABOUT 30 to 40 MPH 1000 FEET ABOVE THE SURFACE 35 MPH FOR 6 HOURS IS ABOUT 200 MILES

Slide31: 

Model Depiction of the Low Level Jet High Wind Speeds In Red 9:00 PM 11:00 PM 01:00 AM 03:00 AM 05:00 AM 07:00 AM

How Much Ozone May be in the Low Level Jet?: 

How Much Ozone May be in the Low Level Jet? Still analyzing this issue Theory and recent work by Penn State around Philadelphia (using laser technology called LIDAR) indicates that the low level jet can routinely carry 80 to 90 ppb ozone.

Take Home Messages: 

Take Home Messages The Washington areas air quality is significantly affected by transport from upwind areas to the west and the south On the worst ozone days well over half of the measured ozone in Washington originates in upwind states Sources that transport pollution to Washington include power plants, cars and area sources.

Policy Implications: 

Policy Implications Current suite of NOx controls is good but more will be needed 2003/2004 “NOx SIP Call” 2007 Tier 2 vehicle and heavy duty diesel standards Congressional debate over “multi- pollutant” power plant legislation (Clear Skies Act, etc.) will be critical Low level jet issue raises some interesting new questions Should the “level playing field” for mobile and area source controls be stretched to the south?

Key Transportation Issues: 

Key Transportation Issues Are the mobile source reductions in the Washington area needed? Yes, on some days local mobile emissions drive our high ozone New, tougher standards for ozone and fine particulate begin in 2004 and will require even more controls

Key Transportation Issues(continued): 

Key Transportation Issues (continued) Should areas to the south and west of the Washington area be subject to the same level of mobile source controls now require in DC? Yes, the playing field for mobile source controls should be leveled from Atlanta to Boston Maryland’s new low level jet research supports this

Key Transportation Issues(continued): 

Key Transportation Issues (continued) Shouldn’t other sources (like power plants) be regulated better before local mobile sources are further controlled? Yes and no. MDE is pushing very hard for tougher controls on upwind power plants and areas sources. Local reductions still help!!! Conformity is required in the Clean Air Act With or without reductions in upwind areas