ANALYSIS OF 20022008 OZONE EVENTS IN THE OTR

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ANALYSIS OF 2002-2008 OZONE EVENTS IN THE OTR

• Tom Downs

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• ANALYSIS REGIONS (sites plotted in the
  OTR are the only sites used in the analysis)
• Mt Washington-Southern New Hampshire-Coastal
  Maine Marginal or high elevation overwhelming
  transport classification areas?
• Southern New England Albany New York
  Marginal-Moderate?
• Eastern Pennsylvania- Southeastern New York- New
  Jersey Marginal Moderate?
• Delaware-Maryland-DC-Virginia (OTC portion)
  Marginal Moderate?
• Western Pennsylvania-Western New York Marginal
  Moderate?

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Guidance on the Use of Models and other Analyses
for Demonstrating Attainment of Air Quality Goals
for Ozone, PM2.5, and Regional Haze selecting
episodes

• At a minimum, four criteria should be used to
  select time periods which are appropriate to
  model
• 1) Simulate a variety of meteorological
  conditions
• a) 8-Hour Ozone- Choose time periods which
  reflect a variety of meteorological conditions
  which frequently correspond with observed 8-hour
  daily maxima gt 75 ppb at multiple monitoring
  sites.
• b) 24-Hour PM2.5- Choose time periods which
  reflect a variety of meteorological conditions
  which frequently correspond with observed 24-hour
  averages gt 35 ug/m3 at violating monitoring
  sites.
• c) Annual PM2.5- Choose time periods from each
  quarter which reflect the variety of
  meteorological conditions which represent average
  concentrations for that quarter and year
• d) Regional Haze- .Choose time periods which
  reflect the variety of meteorological conditions
  which represent visibility impairment on the 20
  best and 20 worst days in the Class I areas
  being modeled.
• 2) Model time periods in which observed
  concentrations are close to the appropriate
  baseline design value or visibility impairment.
• 3) Model periods for which extensive air
  quality/meteorological data bases exist.
• 4) Model a sufficient number of days so that the
  modeled attainment test applied at each monitor
  violating the NAAQS is based on multiple days.

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• 1) Simulate a variety of meteorological
  conditions
• a) 8-Hour Ozone- Choose time periods which
  reflect a variety of meteorological conditions
  which frequently correspond with observed 8-hour
  daily maxima gt 75 ppb at multiple monitoring
  sites.

• Detailed meteorological analyses for each type of
  event for each region were not performed and
  probably are not necessary. Sea level pressure,
  850mb height and 850mb temperature analyses for
  each season and significant events are shown in
  the slides at the end of this presentation.
• 2002, 2005 and 2007 have the most events to
  evaluate.
• 2002 has already been shown to be a good year to
  model for the 97 Ozone standard.

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• 2) Model time periods in which observed
  concentrations are close to the appropriate
  baseline design value.

• Preliminary 2006-08 Design Values range from 76
  to 92 ppb in the OTR.
• 88 of the events have observed concentrations
  meeting this criteria in 2005 and 2007 compared
  with 64 in 2002.

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• 3) Model periods for which extensive air
  quality/meteorological data bases exist.

• 2002 meteorological data has already been
  processed for the ozone season. 2005?
• 2002 and 2005 are periodic inventory years.
• LADCO has already determined that 2005 is the
  best year for their region.

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• 4) Model a sufficient number of days so that the
  modeled attainment test applied at each monitor
  violating the NAAQS is based on multiple days.

2002, 2005 and 2007 contain more than one
regional event (3 or more consecutive days with
exceedances in 4 regions).
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Preliminary 2006-08 8-hr O3 NAAQS DESIGN VALUE
Nonattainment Site Map
2002, 05, 08 INVENTORY YEAR 4th highest 8-hr
O3 Concentration Maps Only 1 site in the
NH/CoastalME region with a 2008 4th high greater
than the standard
High elevation overwhelming transport
Classification?
OTR MODERATE or HIGHER CLASSIFICATION? REGIONS
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2003, 04, 06 07 4th highest 8-hr O3
Concentration Maps / All regions have 4th
highs greater than the standard
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Meteorological data reanalysis
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2002-2008 April-September Mean Sea Level
Pressure NCEP/NCAR REANALYSIS
2002

• Surface high pressure more persistent and
  covering more area in 2002 than any other season.

2003
2004
2005
2006
2007
2008
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2002
2002-2008 April-September Sea Level Pressure
Anomalies NCEP/NCAR REANALYSIS
2003
2004
2005
2006
2007
2008
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2002-2008 April-September Mean 850mb
Height NCEP/NCAR REANALYSIS
2002

• 850mb ridge strongest in 2002 with the ridge
  also reaching further north in 2007 (2 worst
  years for Northern New England.

2003
2004
2005
2006
2007
2008
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2002-2008 April-September 850mb Height
Anomalies NCEP/NCAR REANALYSIS
2002
2003
2004
2005
2006
2007
2008
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2002
2002-2008 April-September Mean 850mb Temperature
NCEP/NCAR REANALYSIS
2003
2004
2005
2006
2007
2008
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2002-2008 April-September 850mb Temperature
Anomalies NCEP/NCAR REANALYSIS
2002
850mb temperatures generally warmer than
(1958-96) normal for all years with 2005 the
warmest.
2003
2004
2005
2006
2007
2008
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Exceedance day meteorological conditions
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2002 EXCEEDANCE DAYS OCCURRING IN 4 CORE REGIONS
OF THE OTR
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JUNE and JULY 2002 EXCEEDANCE DAYS OCCURRING IN 4
CORE REGIONS OF THE OTR
SEA LEVEL PRESSURE 850mb HEIGHTS
850mb TEMP
AUGUST and SEPTEMBER 2002 EXCEEDANCE DAYS
OCCURRING IN 4 CORE REGIONS OF THE OTR WORST CASE
METEOROLOGY FOR ALL REGIONS
SEA LEVEL PRESSURE 850mb HEIGHTS
850mb TEMP
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2003 EXCEEDANCE DAYS OCCURRING IN 4 CORE REGIONS
OF THE OTR
SEA LEVEL PRESSURE 850mb HEIGHTS
850mb TEMP
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2004 EXCEEDANCE DAYS OCCURRING IN 4 CORE REGIONS
OF THE OTR
SEA LEVEL PRESSURE 850mb HEIGHTS
850mb TEMP
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2005 EXCEEDANCE DAYS OCCURRING IN 4 CORE REGIONS
OF THE OTR
SEA LEVEL PRESSURE 850mb HEIGHTS
850mb TEMP
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2006 EXCEEDANCE DAYS OCCURRING IN 4 CORE REGIONS
OF THE OTR
SEA LEVEL PRESSURE 850mb HEIGHTS
850mb TEMP
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2007 EXCEEDANCE DAYS OCCURRING IN 4 CORE REGIONS
OF THE OTR
SEA LEVEL PRESSURE 850mb HEIGHTS
850mb TEMP
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2008 EXCEEDANCE DAYS OCCURRING IN 4 CORE REGIONS
OF THE OTR
SEA LEVEL PRESSURE 850mb HEIGHTS
850mb TEMP
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SUMMARY

• 2002 is the best year meteorologically but is
  before the NOx SIP call reductions
• 2005 and 2007 are the next best years for all
  regions. Both years had exceedances in all
  months of the season
• 2005 is the best year to model for LADCO and the
  Western PA/NY region with 2007 the best year for
  the New England regions.
• 2005 would be the best year to model because it
  is a periodic inventory year is the same year
  LADCO is modeling.