Martin O’Malley, Governor | Anthony G. Brown, Lt. Governor | Robert M. Summers, Ph.D., Secretary
PM2.5 Prediction & Analysis:Maryland’s Toolbox
Laura Warren, Senior Meteorologist
National Air Quality Conference
February 11, 2014
PM2.5 Prediction & Analysis
• Background• PM2.5 Progress
• Climatology
• Forecasting & Analysis Tools
• Case Studies
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Progress with PM2.5
• EPA revised the annual PM2.5 NAAQS from 15 to 12 ug/m3 in 2012• Retained the 24-hour
NAAQS of 35 ug/m3
• Many areas already meet the new annual NAAQS
• Many areas also already meet the 24-hour PM2.5 NAAQS of 1997 and 2006
Credit: EPA3
Progress with PM2.5 in Maryland
• Maryland is measuring clean data with both the annual and the daily PM2.5 standards
• Seeking redesignation to attainment status from EPA for Baltimore and Washington, D.C. nonattainment areas
• Maryland Healthy Air Act and other state, regional, and federal control strategies have played a large role in this improvement
15.8 15.914.5
11.7 11.3
17.1
11.1
12.915.616.215.9
0
4
8
12
16
20
2002 2004 2006 2008 2010 2012
Ann
ual P
M2
.5 (
ug/m
3)
Annual Fine Particles in Maryland41 41 39
35
2930
42 4137
3329
2002 2004 2006 2008 2010 2012
Dai
ly P
M2.
5 (u
g/m
3 )
0
10
20
30
40
50Daily Fine Particles in Maryland
Previous NAAQS
Current NAAQS
Current NAAQS
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PM2.5 Composition
• Sulfate is the largest component at nearly 30%
• Organic carbon is second at about 25%
• Nitrate and ammonium are about 10% each
• During the summer, sulfate contributes most to PM2.5 while nitrate drives wintertime trends
Dust3%
Elemental Carbon5%
Organic Carbon25%
Sulfate27%
Nitrate11%
Ammonium12%
Other17%
PM2.5 Composition at Essex, MD2004 – 2006
Credit: MDE, 20085
Maryland PM2.5 Climatology
• Seasonally, PM2.5 exhibits 2 maximums• June – August
• Late December – February, depending on the region
• 5 exceedance days per year are observed on average• 4 exceedance days in 2013
Credit: W. F. Ryan & N. T. Wiles, 2012
Metropolitan Baltimore 7-Day Running Average 24-Hour PM2.5
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Revised PM2.5 AQI
• Revised AQI effective March 2013• Changed low Moderate
range from 15.5 to 12.1 ug/m3
• No change to Code Orange+
• Impacts on Maryland• About 70 more Moderate
days for PM2.5
More information on Maryland and the revised AQI is here.
Change in 24-Hour PM2.5 AQI for Maryland
0.2 days
5 days
0 50 100 150 200 250
Good
Moderate
USG
Unhealthy
Average No. of Days for 5 Years (2008-2012)
Previous AQI
Revised AQI
+70 days
No Change in USG, Unhealthy, Very Unhealthy
AQI Days
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Prediction & Analysis
• Tools used by MDE for PM2.5 will be highlighted from multiple perspectives:• Air quality forecasting• Poor air quality case studies
• Forecast verification• Understanding severe episodes• Exceptional events
• Unusual or naturally occurring events that are not reasonably controllable causing an exceedance of the NAAQS
• Clear, causal relationship between the measurement and the event
• Measured concentration were in excess of normal historical fluctuations
• Prove there would have been no exceedance but for the event
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Well-Known Forecasting Tools
• AirNow-Tech• Navigator
• Data query
• WPC products including the model diagnostics discussion
• Meteorological models• NCEP
• Weather Underground
• Penn State e-WALL
• HYSPLIT trajectories• Air quality models
Credit: AirNow, Environment Canada, NASA, NCAR, NCDAQ, NOAA, NRL; Initial design: D. Nguyen9
Airmass Transport
• HYSPLIT Trajectories• Web-based
• Forecasting and retrospective analysis
• Comparisons between GFS vs. NAM trajectories
• PC-based for retrospective analysis• Generate multiple
trajectories in a batch process
• Cluster analysis can be further investigating using statistical software like R or MeteoInfo TrajStat
Cluster Analysis: Jennifer Hains, PhD10
Airmass Transport
• HYSPLIT Dispersion Model• Can provide a forecaster with a
rough idea of a wildfire’s PM2.5 transport
• Must run the dispersion model as a “prescribed burn”
• Model needs to know…• Coordinates of the fire location• Acreage of the burn area• Inciweb website may have this
information available• Graphics or KML is generated
at the user’s request
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Boundary Layer Height
• The planetary boundary layer height (PBL) is important, especially for wintertime episodes
• Obtained from:• NWS station skew-T’s
• Lidars
• Radar wind profilers (RWP) and radio acoustic sounding systems (RASS)• Virtual temperature• Signal-to-noise ratio
Credit: NASA, Plymouth State University12
Boundary Layer Height
• Signal-to-Noise Ratio• Comparable to backscatter
from lidar• Useful for post analysis• PBL heights analyzed
subjectively or by an algorithm developed by UMBC
dB
Source: MDE
PBL analyzed by MDE meteorologist
Residual layer
Source: UMBC Location: Baltimore, MD
Residual layer
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Fire Detection
• NESDIS Hazard Mapping System (HMS)• Hotspots and smoke plumes by
satellite analysts
• NASA FIRMS MODIS email alerts
• GOES-East Eastern Region satellite imagery• Satellite loops provided with
visual enhancements to aid in smoke plume detection
• RGB satellite products• MODIS, VIIRS, GOES• Can illustrate the direction of
smoke transport for exceptional event analysis
Credit: NOAA
Smoke
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Aerosol Optical Depth
• Satellite measurements from MODIS, VIIRS, and GASP• Helpful for spatial
representation of aerosol measurements
• Most often accessed via the IDEA website• Comparisons of AOD
between each satellite sensor
• Very useful interactive platform for VIIRS products
• Easy to compare AOD for five different quality levels
Credit: IDEA, NASA15
Aerosol Optical Depth
• AERONET• Ground-based remote sensing
to detect parameters such as AOT and aerosol size distribution
• Higher temporal resolution than satellite AOD
• Data quality levels of 1.0, 1.5, 2.0 to select depending on use
• AERONET Synergy Tool, optimized for episode analysis, provides wide range of datasets
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Air Quality Models
• NOAA Developmental PM2.5
• Currently used in a qualitative sense, and it seems to do well in this way
• NOAA Operational Smoke• Used to indicate potential
impacts to Maryland from nearby fires
• NRL Operational Aerosol• Smoke, sulfate, dust• Sulfate can be helpful in
summer• Comparisons between models
• NOAA smoke vs. PM2.5 for exceptional event “but for” case
• NRL vs. NOAA smoke
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Quebec Wildfires 2002
• Air quality influenced by smoke from Quebec wildfires on July 7 - 9, 2002
• Northwesterly flow, usually associated with clean air, due to high pressure in the Midwest and low pressure in the Gulf of Maine
• Resulting air quality:• Code Red (Unhealthy) for
PM2.5
• Code Purple (Very Unhealthy) for ozone
Credit: Environment Canada, NOAA, NASA
Predominant
Flow
Surface Analysis12z July 7, 2002
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Quebec Wildfires 2002
In this case, limited data at quality level 1.5, but AOD indicates a rising trend
AOD size distribution
shows primarily fine particles
Smoke descending throughout the day
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Good/Moderate Episode 2013
• PM2.5 forecasting for the East Coast is often a battle between Good/Moderate AQI
• September 8, 2013• A mix of Good and Moderate
conditions
• 24-hour averages:11 – 18 ug/m3
• Hourly averages:3 – 30 ug/m3
• Warm and moist conditions ahead of a slow moving cold front
Credit: AirNow-Tech, EPA AirData
Hourly PM2.5 in MD & VA Sept. 8, 2013
Surface Analysis12z Sept 8, 2013
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Good/Moderate Episode 2013
• AOD is somewhat elevated on the 8th
• GASP indicated higher AOD than MODIS
• AOD coverage seems sparse in our region, sometimes due to cloud cover
• VIIRS cloud screening and other QC processes tend to throw out more data than MODIS, an issue being investigated by NOAA
• NOAA developmental PM2.5 model indicated concentrations may not return to the Good range on the 8th
Credit: NOAA WPC, IDEA21
Winter Stagnation 2013
• A rare episode of PM2.5 exceedance days• December 2 – 4, 2013
• Highest 24-hour average was on the 3rd at Hagerstown measured 45.7 ug/m3
• Highest values were in rural valley areas like Hagerstown, but urban areas weren’t far behind
• Persistent high pressure system caused stagnation• Some sites (Fairhill) showed the
classic diurnal wintertime pattern
• High nocturnal PM2.5 followed by relief when the afternoon inversion broke
0
10
20
30
40
50
60
0 6 12
18 0 6 12
18 0 6 12
18 0 6 12
18 0 6 12
18 0 6 12
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PM
2.5
Co
nce
ntr
atio
n (u
g/m
3)
Hour (EST)
Maryland Area PM2.5 MonitorsNov. 30 - Dec. 5, 2013
HagerstownWinchester, VAOldtownEdgewoodFairhillNAAQS
Surface Analysis00z Dec. 4, 2013
24-Hour Average PM2.5Dec. 4, 2013
11/30/13 12/1/13 12/2/13 12/3/13 12/4/13 12/5/13
Credit: NOAA WPC, AirNow-Tech22
Winter Stagnation 2013
• In addition to mostly calm winds through the period, a strong temperature inversion trapped pollutants in a shallow boundary layer
• RASS shows PBL height varying from 100 – 500m on the 4th
• Algorithm using the wind profiler’s signal-to-noise ratio (SNR) shows PBL heights between 200 – 600m• Profilers’ SNR values are more defined in humid atmospheres and, as a result, the
algorithm may perform best in the summer
Credit: NOAA/MADIS
PBL PBL
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Summary
• Many meteorological products and tools geared toward aerosols• Airmass transport through HYSPLIT trajectory and dispersion model
products• Boundary layer heights via skew-T, lidar, radar wind profilers, and RASS• Many fire detection tools through NASA and NOAA• AOD derived from satellite sensors MODIS, VIIRS, and GASP, and
ground-based instruments through AERONET
• Aerosol models run by NOAA for smoke and PM2.5 as well as by NRL/Monterey for smoke, sulfate, and dust
• Future Products: Research is ongoing to improve spatial resolution for ground-level PM2.5 through the integration of satellite data, particularly in air monitor sparse areas• AirNow Satellite Data Processor (ASDP)• NASA Air Quality Applied Sciences Team (AQAST)• NASA DISCOVER-AQ Mission
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Resources
• Measurements:• NASA AERONET data synergy tool• NASA FIRMS MODIS fire alerts• NASA MicroPulse Lidar Network
(MPLNET)• NOAA/MADIS
Cooperative Agency Profilers• NOAA/NESDIS
Hazard Mapping System• NOAA/NESDIS IDEA• NOAA/NESDIS satellite loops with
enhancements• NOAA/NCDC recent snowfall maps• NOAA/NOHRSC
national snow analysis• UMBC Smog Blog
• Models:• MeteoInfo TrajStat• NOAA/ARL HYSPLIT, more on
automation here
• NOAA PM2.5 Developmental Model• NOAA Smoke Model• NRL/Monterey Aerosol Model
• References:• Compton, J., R. Delgado, T. Berkoff, and R. Hoff,
2013: Determination of planetary boundary layer height on short spatial and temporal scales: A demonstration of the Covariance Wavelet Transform in ground based wind profiler and lidar measurements. J. Atmos. Oceanic Technol. doi:10.1175/JTECHD-12-00116.1.
• Ryan, W. F. and N. T. Wiles, 2012: PM2.5 Forecast Climatology for Maryland. 28 pp.
• Maryland Department of the Environment (MDE), 2008: Appendix G-11-2: Weight of Evidence Report Appendices. Baltimore Nonattainment Area PM2.5 State Implementation Plan and Base Year Inventory. SIP Number: 08-04. 1735 pp.
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Questions?
Laura WarrenAir Monitoring Program
Maryland Department of the Environment(410) 537-3122 | [email protected]
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