Project Outline: Technical Support to EPA and RPOs on the Implementation of the Regional Haze Regulations Estimation of Natural Haze as Part of Total Haze over the US R. Husar, CAPITA Washington University, St. Louis Project Period: June 2003- May 2008; Reports: 2005, 2008 Presentation prepared for CENRAP Meeting, San Antonio, Jan. 24, 2003 Oct 5, 1998 Oct 5, 1998 Smoke Plumes Smoke Plumes Regional haze from smoke? SeaWiFS Satellite Aerosol Pattern Natural/Manmade?
Transcript
Project Outline:
Technical Support to EPA and RPOs on the Implementation of the Regional Haze Regulations
Estimation of Natural Hazeas Part of
Total Haze over the US
R. Husar, CAPITAWashington University, St. Louis
Project Period: June 2003- May 2008; Reports: 2005, 2008Presentation prepared for CENRAP Meeting, San Antonio, Jan. 24, 2003
Oct 5, 1998 Oct 5, 1998
Smoke Plumes Smoke Plumes
Regional haze from smoke?
SeaWiFS SatelliteAerosol Pattern
Natural/Manmade?
Summary of EPA Haze Rule on Natural Conditions
• The goal of the EPA visibility program is reaching the natural visibility conditions.
• Estimating the overall visibility conditions and the natural conditions establishes how ‘‘close’’ a Class I area is to the goal, i.e. the magnitude of the human-induced ‘exceedance’ over the natural.
• The default annual natural visibility is 11-12 deciview for the East, 8 dv for the West.
• The regional natural visibility is to be derived from sulfate, nitrate, organic carbon, elemental carbon, and crustal material estimates using IMPROVE methodology.
• EPA along with States, tribes, and FLMs to develop and refine the technical guidance on estimating natural conditions (e.g. natural fire and dust)
• States, in turn, will work with the FLMs, tribes and EPA in estimating their natural conditions using these guidelines at each Class I area.
The Haze Rules require States to establish and update
Baseline, Natural and Current Visibility Conditions
• Baseline conditions represent visibility at the time the regional haze program is established, 2000-2004
• Natural conditions represent the visibility conditions that would be experienced in the absence of human-caused impairment.
• Current condition is the most recent multiyear average, to be revised for each SIP revision. It includes showing progress from the baseline period.
Regional Haze Rule: Nomenclature and Time Scale Schematics
Time Scale and Milestones
Goal is to attain natural conditions by 2064
Baseline is established during 2000-2004
First SIP & Natural Cond. estimate in 2008
SIP & Natural Cond. Revisions every 10 yrs
Haze ComponentsNatural haze is due to natural windblown dust, biomass smoke and other natural processes
Man-made haze is due industrial activities AND man-perturbed smoke and dust emissions
A fraction of the man-perturbed smoke and dust is assigned to natural by policy decisions
Natural Aerosol Conditions – Default Values
WESTEAST
• The Regional Haze Rule provides initial default values for the Natural Haze Conditions
• The default haze for the West is 8 deciviews while for the East is 11 deciviews
• Obtained by estimating the natural concentration of SO4, EC, OC, NO3, Fine, Coarse Soil
• Weighing each aerosol component by corresponding extinction efficiencies. (Trijonis, 1990)
Mass Mass
Bext Bext
Estimation Procedure for Default Natural Haze
• The current natural haze estimation method uses annual average species concentrations and average relative humidity to estimate annual mean natural haze
• The day-to-day variability in the annual mean is natural haze is based on statistical assumptions
All aspects of the default natural haze estimation can be improved with recently obtained data and analysis techniques:
RH Guide on Fire Emissions
• Forest and other fires can be either natural or man-induced
• Many major forest fires can be inherently classified as natural
• Other fires are intentional (prescribed) to reduce organic fuel accumulation
• Prescribed burning will likely be increasing to reduce catastrophic wildfires
• EPA considers some portion of the prescribed fire emissions as ‘natural’.
• The Western Regional Air Partnership (WRAP) is conducting interesting policy discussions on defining natural and manmade smoke
• Regional Haze guide document is vague on natural dust
• The WRAP RPO has conducted an extensive evaluation of fugitive dust in the West. They concluded that manmade fugitive (mechanically stirred up) dust is not a significant contributor regional haze. By inference, most of the regional dust in the west is non-fugitive windblown dust.
• In an early discussion document, Pitchford suggests that a working definition of natural dust could be any dust from non-disturbed soil surfaces, while all the dust from disturbed surfaces would be classified as manmade.
• Clearly, there is a to begin both the scientific/technical as well as the policy discussion about natural/manmade dust.
The goal of the project is to provide technical support to EPA & RPOs on:
Estimation of Natural Haze as Part of Total Haze over the US
Tasks and Approach:
1. Conceptual Evaluation of Natural PM and Visibility Conditions• Establish Virtual Workgroup with representatives from EPA, RPOs, scientific community
2. Quantitative Estimation of Current Total and Natural Contribution • Conduct Data Analysis for estimating natural contributions (1995+, surf. and satellite obs)
3. Real-Time Estimation of Natural Aerosols and Visibility• Implement a Web-based Tool for routine real-time estimation of natural aerosols/visibility
Task 1: Conceptual Evaluation of Natural PM and Visibility Conditions
Technical Issues• Establish the main natural source types and their properties
– Windblown dust (local and distant)
– Biomass smoke (forest, grass and other uncontrolled fires, local and distant)
– Spatio-temporal scales, resolution and pattern of natural events/conditions
Project Management Approach
• Establish a steering group for project guidance (EPA, RPO, Science reps)
• Maintain a project website for open virtual workgroup interaction and data sharing
• Follow and interact with policy developments at RPOs and EPA
• Collaborate with VIEWS, RPO data analysts and RPO modelers
Task 1: Natural Haze Properties
• Dust, sea salt and pollen are ‘coarse’ particles.
• Dust is composed of irregularly shaped crystals
• Sea salt is made of rectangular crystals of NaCl
• Pollen are round shaped solid organic particles.
• Smoke and marine biogenic particle are ‘fine’
• Smoke particles are droplets of organics from combustion residues
• Marine organic particles droplets are from microorganisms on the sea surface
Sahara Dust
Task 2: Quantitative Estimation of Regional Natural Contribution
Current Conditions (from VIEWS)• Spatially resolved haze components for each station, focus on Class I areas• Temporally resolve aerosol components for each day• Apply IMPROVE methodology for total haze calculation , including RH Correction• Identify worst/best visibility days
Natural Haze (from this Project)• Spatially resolve natural (dust, smoke, other) for each station, focus on Class I areas• Temporally resolve natural haze components for each day • Apply IMPROVE methodology for natural components, including RH Correction• Estimate the natural contribution on best/worst visibility days• Compare Natural Haze to Total Haze on best/worst days
• Implied in this approach is that:Current Conditions and the Natural Conditions are analyzed simultaneouslyThis project is closely coordinated with other source apportionment work
Current 1996-98 Haze Conditions (IMPROVE)
• The current haze level along the West Coast is >15 dv, well over the default 8 dv
• Much of the mountainous West is in the 8-10 dv range, very near the default natural value
• Most of the Eastern US (except the Upper MW and New Engl.) is above 20 dv, compared to the default of 12 dv natural default.
• Expressed as extinction coefficient, the current EUS haze is about 90 Mm-1 compared to the default natural value of about 30 Mm-1
• Hence, as a very rough initial estimate, the EUS extinction levels are currently about 3 times the default natural haze stated in the Regional Haze Regs.
Significant Natural Contributions to Haze by RPO Judged qualitatively based on current surface and satellite data
• Natural forest fires and windblown dust are judged to be the key contributors to regional haze• The dominant natural sources include locally produced and long-range transported smoke and dust• This project will quantify the absolute and relative contribution of natural sources for each RPO
WRAP
Local Smoke
Canada Smoke
Local Dust
Asian Dust
VISTAS
Local Smoke
Sahara Dust
MRPO
Local Smoke
Canada Smoke
Local Dust
CENRAP
Local Smoke
Mexico/Canada Smoke
Local Dust
Sahara Dust
MANE-VU
Local Smoke
Canada Smoke
Natural Aerosol/Haze Analysis Tools
Analysis Tools
• Chemical composition analysis (speciation, traces)
Task 2: Dust Analysis- Local, Sahara and Gobi Dust over N. America
• The dust over N. America originates from local sources as well as from the Sahara and Gobi Deserts
• Each dust source region has distinct chemical signature in the crustal elements.
• The pattern of different dust contributions varies in space as well as by season, episodicity and vertical distribution
• New satellite sensors allow monitoring the spatial and temporal pattern of dust events on a daily basis.
• Dust particles are irregularly shaped crystals• Virtually all the dust mass is over 1 m in size• The mass mean diameter (MMD) of dust near
the source is over 5-10 m• However, long range transported dust (3-10 days
old) has MMD of 2-5 m• Hence local dust is virtually all in the coarse
mode (>2.5 m) while long-range dust has 30-50% of the mass in the PM2.5 range.
Task 2: Quantitative Estimation of Regional Natural Contributions
Approach:• Study each natural aerosol type in detail (dust, smoke, biogenic, sea salt)• Use ALL available aerosol observations (surface and satellite) and model results• Establish source strength/variability and spatio-temporal pattern at relevant scales (e.g.natural aerosol statistics)•
Example Natural Aerosol Analyses: Fine Dust
In July, in the Southeast, Sahara dust contributes 4-8 g.m3,
about 2-4 times the local fine dust.
July
SeaWiFS satellite image of Sahara dust approaching the continent (July 24,1998).
For more detail see: Local and Global Dust Over N. America
Task 3. Real-Time Estimation of Natural Aerosols and Visibility
Real-time Aerosol Watch System (RAW)
Real-Time Virtual PM Monitoring Dashboard. A web-page for one-stop access to views of current PM/Visibility monitoring data (aerosol, weather) and model output for nowcasting and forecasting.
Virtual Workgroup Website. An interactive website which facilitates the active participation of diverse members in the interpretation, discussion, summary and assessment of the aerosol events.
Air Quality Managers Console. Delivers a packaged PM data and summary reports prepared by the Virtual
workgroups. Helps PM managers make decisions during major aerosol events.
Rationale
• The dominant natural aerosol sources are from windblown dust and biomass smoke.
• Dust and smoke events can be monitored real-time by numerous surface and satellite sensors.
• Both are ‘episodic’, i.e. short-term extreme concentrations that require AQ management actions.
The development and implementation of RAW is already being supported at CAPITA by grants from NSF, NOAA, EPA/EMAP, NASA(pending). Incremental funding from this project would support estimating ‘Natural PM/Visibility Contributions’ during such events.
Right. SeaWiFS satellite and METAR surface haze shown near-real time in the Voyager distributed data browser
Below. SeaWiFS, METAR and TOMS Absorbing Aerosol Index superimposed
Satellite data are fetched from NASA GSFC; surface data from NWS/CAPITA servers
Task 3: Illustration of RAW for Quebec Smoke, July 6, 2002See http://capita.wustl.edu/aerosolevents
