Title: Fine scale air quality modeling using dispersion and CMAQ modeling approaches: An example application in Wilmington, DE
1Fine scale air quality modeling using dispersion
and CMAQ modeling approaches An example
application in Wilmington, DE
- Jason Ching
- NOAA/ARL/ASMD
- RTP, NC
- Ching.jason_at_epa.gov
2Collaborators
- Mohammed A Majeed
- Delaware Department of Natural Resources and
Environmental Conservation - New Castle, DE
- Vlad Isakov
- Atmospheric Sciences Modeling Division, NOAA
RTP, NC - Andrey Khlystov
- Duke University,
- Durham, NC
3Outline of Presentation
- Background and Rationale of investigation
- Conceptual Hybrid modeling approach
- Description and role of EDATAS database to fine
scale air toxic modeling - Future Plans
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5Example of regional and local model results
Hybrid approach (CMAQ with local scale modeling)
4 km CMAQ only
CMAQ and Hybrid results for Philadelphia study
reflecting enhanced details to CMAQ from
incorporating local scale modeling with the
hybrid approach
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7- Hybrid approach provides a means for introducing
fine scale concentration detail to regional scale
model simulations - This approach needs to be evaluated
-
- A collaboration of opportunity!
- Field study monitoring program, EDATAS, Enhanced
Delaware Air Toxics Assessment Study focus on
Wilmington, DE - Concurrent investigations to characterize fine
scale fields of air toxics and PM - Continue investigations toward advancing the
development of advanced air quality modeling
tools for air toxics and other applications.
8- A rich database of air toxics measurements to
provide - Better understanding of the micro-level air
quality impacts of emission sources. - (2) Enhanced spatial resolution of the ambient
toxics dataset throughout city and variability at
spatial scales of order 100m by mobile
measurements - (3) Means to evaluate our hybrid approach
Measurements of Ozone, HCHO, Cr(VI), fine
particles
9Grids for concentration distribution at
neighborhood scales
10Neighborhood scale variability of
formaldehyde(summer 2005)
- The X-axis shows the concentration of HCHO in
?mol/m3 - The Y-axis shows the number of observations.
11COMMENTS on EDATAS
- The EDATAS database of toxics (including HCHO and
Cr(VI) measurements using mobile van transects
provide a unique, albeit limited bases for
characterizing air toxics at neighborhood scales. - Future efforts will focus on utilizing such data
for evaluating and assessing advanced air toxics
modeling such as hybrid modeling approaches.
12Fine scale model investigations for Wilmington, DE
- Modeling is the only tool that provides a link
between sources and ambient concentrations - Modeling at fine scales need evaluation. EDATAS
will be used for this purpose. - Model ready detailed emission inventory has been
prepared, including road-linked emissions data. - Air toxics version of CMAQ to be run in nested
mode to 1 km grid size - Local scale modeling (using AERMOD) applied to
local emission sources, thus providing sub grid
information to CMAQ at 4 km or greater - Preliminary results follow Example simulation is
for a July, 2001 average.
13Example Regional to fine scale using Nested grid
CMAQ (benzene)
Aurban Burban Crural
A B
C
(A) 12 km
(B) 4 km
(C) 1 km
14Example of Time Series for HCHO CMAQ (12km)
95th percentile from the 12x12 distribution
(based on 1 km grid CMAQ results Grid cell A
Urban (see previous slide)
0 2 4 6 8
10
HCHO Concentration (ppb)
Jul 1 4 8 12 16
20 24 28 Aug 1
15Example of local contributions of HCHO using
AERMOD. Information to be used with CMAQ as
needed for the hybrid approach
16Next steps
- Implement the hybrid approach by incorporating
local scale with CMAQ modeling - Evaluate and assess both such outputs with EDATAS
database (of mobile measurements) - Perform additional CMAQ modeling at 1 km grid
size to investigate fine scale resolution of
combined regional and local scale contributions
to investigate the characteristics of SGV and
corresponding distribution functions as a
complement to CMAQ at grids sizes of 4 and 12 km.
- Explore and examine the merits of applications
that utilize (a) hybrid modeling approach as well
as (b) an enhanced CMAQ system that is
complemented with SGV distributions. e.g., - Performing exposure analyses, health risk
assessments - Performing grid model evaluation
- Weight of Evidence RRF/DV(CF) analyses for SIPS
17The End Thank you for your attention
- Disclaimer The research presented here was
performed under the Memorandum of Understanding
between the U.S. Environmental Protection Agency
(EPA) and the U.S. Department of Commerce's
National Oceanic and Atmospheric Administration
(NOAA) and under agreement number DW13921548.
This work constitutes a contribution to the NOAA
Air Quality Program. Although it has been
reviewed by EPA and NOAA and approved for
publication, it does not necessarily reflect
their policies or views.