A Simplified Conceptual Model for the Ozone Transport Region

1. A Simplified Conceptual Model for the Ozone Transport Region Where does our air pollution come from and what do we need to do to fix it? OTC Modeling Committee Meeting Tad Aburn, MDE April 26, 2005

2. Current Status • Still a work in progress • Clearly targets policy makers • More detailed conceptual descriptions available • Much thanks to • UMD • CT • NH • NESCAUM • MARAMA

3. Why a Conceptual Model For the OTR? • Need an overarching vision of what it will take to clean the air. • The SIP process alone, unfortunately, won’t do it. • We need to constantly revisit the “will it clean the air” question and target resources to maximize clean-up. • We need to bend and twist the SIP process to get what we want.

4. Simplified OTR Conceptual Model* Four Distinct Parts • Emissions from within the OTR • Three types of transport • Short range • VA to MD to PA to NJ to NY to MA to NH. • 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 and other pollutants * The conceptual model work has been driven primarily by ozone. As PM Fine research evolves we are learning that there are many similarities

5. How Much Is Transport? • On our worst days we use airplanes to measure ozone at 110 parts per billion (ppb) floating into the southern portion of the OTR from the West • Varies with changes in meteorology but for most OTR nonattainment areas best guess is something like: • 30 to 40 percent long range (westerly) transport • 10 to 20 percent short range transport • 10 to 20 percent LLJ • 10 to 20 percent local • Local SIPs will only address this last 10 to 20 percent

6. The Transport “Crossroads” • The Mid-Atlantic “Crossroads” • Westerly transport • Low-level night-time jet transport from the south • Local transport from southwest to northeast • Jets, sea breezes, the lee-side trough and other coastal meteorology all turn pollution northward at the Mid-Atlantic crossroads

7. The Phases of a Bad Ozone Day • Three Stages of an Ozone Event • Up to around 10 - The elevated reservoir • 10 to 12 – Inversion breaks – the “regional” signal • Afternoon – Local and regional pollution combine Mid-Atlantic Ozone Monitoring Data

8. The Different Types of Transport • Short range transport • SW to NE transport • Mobile, area and stationary sources • Long range westerly transport • West to east transport • Primarily from power plants • Low Level Night-Time Jets • SW to NE transport • Mobile, area and stationary sources • The “elevated reservoir” • Complex mixture of ozone and ozone precursors

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

10. How Big is the Reservoir? Approximately 1,000 meters (or 3,000 feet) above the surface

11. 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.

12. Filling the Reservoir • What’s over Baltimore on Tuesday started off in Ohio and North Carolina on Monday. • Maryland’s pollution soup floats to New Jersey and New York • New York’s pollution floats to New England • Power plants, cars, trucks and other sources are all contributors to the elevated pollutant reservoir. • Filled with ozone and ozone precursors. Low Level Jet

13. Westerly Transport • On the worst ozone days “westerly transport” plays a significant role in creating high ozone.

14. Classic Ozone Weather in the Mid-Atlantic The OTR states see very high ozone levels during the summer when a “Bermuda High” sets up over the Carolinas. H

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

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

17. Who is Contributing to the Southern Portion of the OTR’s Ozone Problem? • From EPA’s modeling to support the 22 state regional NOx reduction program called the “NOx SIP Call”

18. Who is Contributing to the Northern Portion of the OTR’s Ozone Problem? • From EPA’s CAIR modeling, for Fairfield County, CT

19. Low Level Jet • Night time transport that moves air from NC to MD, MD to NJ, and northward • The LLJ is funneled northward with 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 • Recent PSU/UMD findings • LLJ is routine not occasional • Almost always a 2 to 5 hr LLJ for MD Orange or red days • Precursor transport – not just O3 Low Level Jet

20. 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. • It’s not just ozone but precursors too!

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

22. 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

23. 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

24. A Bad Day in Connecticut High Ozone Westerly Transport Low Level Jets Coastal Meteorology

25. Different Types of Transport Not Really a New Concept 1998

26. OTC Policies How do they address the different types of transport? • Short Range Transport • Addressed by historical “inside the OTR” strategy and model rule development work • Long Range Westerly Transport • Addressed by OTC Multipollutant Position and Strategy • Low Level Night-Time Jet Transport • Just beginning to address this issue as part of “level-playing-field” effort under the Control Measure Workgroup

27. Good News – Westerly Transport • The NOx SIP Call has actually worked!!! • Significant reductions from regional power plants between 2002 and 2005 • Billions of dollars being invested in “Selective Catalytic Reduction” (SCR) technology to reduce power plant NOx emissions SCR By State Over 50 % of the coal-fired capacity in key upwind states will be controlled with SCR by 2005 1 to 25 % 26 to 49% 50 % or greater

28. Leveling the Playing Field • OTC Control Measure Workgroup is looking at new strategies for inside the OTR • Also looking at how to expand existing OTR control programs into upwind areas • Leveling the playing field has become a more important issue as the low-level jet research has been refined CURRENT PLAYING FIELD GENERALLY WHERE THE PLAYING FIELD SHOULD BE LEVELED MD

29. Next Steps? • Comments today • Continue refinements • Expand to fine particles • Report back to Control Measures Workgroup • OTC Spring Meeting? • Compile/draft more detailed technical report • Build off of MARAMA and NESCAUM work