Ozone transport network
Guoxun Tian
CS 790G
Fall 2010
Overview
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Introduction
My goal and Problems
Methodology
Two way to solve the problems
 How to connect this network to our course?
 Where my data come from?
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Reference
Questions
Transport of East Asian Dust
across the pacific
April 1998 event
R. Husar et al.(1998)
http://en.wikipedia.org/wiki/File:Chinadustmovie.gif
http://en.wikipedia.org/wiki/File:Dust_movie.gif
Why California
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California has the highest ozone level
My goal
 Goal: to build a complex network of ozone transport
based on 15 basins
California is divided into 15 Air Basins to better manage air
pollution. Air basin boundaries were decided by grouping
similar geographic features together. Some air basins really
are like a basin, with valleys surrounded by mountains.
Political boundaries, Such as counties, were also important.
 In this network, the nodes represent all basins and the
edges represent the ozone transportation between them.
My goal
Air pollution emissions from one air basin are
often blown into a neighbor’s air basin
 Local Ozone
Problems
Local ozone concentrations
=
Natural ozone
+
Transported ozone (generated from emissions from upwind
cities and natural events such as wildfires)
+
Local ozone (generated from local anthropogenic emissions)
7
Problems (1 of 2)
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Background ozone
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Transport
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8
What is the typical natural background ozone
concentration?
How much ozone, above natural background, was
transported into each city or basin?
What are the typical source areas for transported ozone?
Problems (2 of 2)
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Local contribution
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Contribution comparison
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9
What amount of locally generated ozone was produced at
each city?
On what percentage of high-ozone days was peak local 8-hr
ozone dominated by locally generated ozone compared to
transported ozone?
How do these percentages change for each city by transport
direction?
How do the contribution amounts compare among the
cities?
Methodology
1. Statistcal Analyses
Analyses of the time of peak ozone concentration at various monitoring sites can yield
useful information on transport patterns and source areas.
A
Morning
B
In most major source areas of interest in California, transport winds are light in
the morning, allowing ozone precursor concentrations to build up and zone to
form.
A
Wind
B
1. Statistcal Analyses
Methodology
2. Back trajectory analysis
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Back trajectory analyses are computer models based on data from past
weather forecasting models that predict how air moves and arrives at a
fixed destination (Yarwood et al., 2000).
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The National Oceanic and Atmospheric Administration (NOAA) provides
a modeling tool known as the HYSPLIT model, which calculates back
trajectories.
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Another tool that calculates back trajectories, VIEWS, provides a similar
product using different assumptions and weather models.
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These tools can be used as indicators as to whether or not a high ozone
level could be attributed to ozone transport from other areas (Yarwood et
al., 2000).
Methodology
Peak Local Ozone = Incoming (natural background + transported
Anthropogenic
anthropogenic) + Local
System
developed to calculate incoming ozone
(Clinton P. MacDonald)
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13
Ran multiple backward trajectories each day for five years
(2001–2005, April–October);
Determined the daily peak 8-hr ozone concentration at the
last site near which each trajectory passed during daylight
hours prior to entering each city; and
Averaged all concentrations to estimate incoming boundary
layer concentration each day.
How to connect this network to our course?
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Do analysis and calculate the centrality, betweennees, closeness
and other parameter of each node to know the relationship
betweeen them
Ozone Transport sketch map of San Francisco Bay Area Air Basin
How to connect this network to our course?
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Do some analysis dynamically, see if we can find a way to reduce
the ozone level of California with minimize cost.
Where my data come from?
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California Environmental Protection Agency:
Air Resources Board.
California’s ambient air monitoring network is
one of the most extensive in the world,
consisting of over 250 sites where air pollution
levels are monitored and more than 700
monitors used to measure the pollutant levels.
Where my data come from?
http://www.arb.ca.gov
Reference
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Clark County Regional Ozone and Precursor Study (CCROPS). Robert A. Baxter,
CCM T&B Systems. Clark County Air Quality Forum – 03/14/06
WESTAR Ozone Transport Analysis. Clinton P. MacDonald, Dianne S. Miller, Sean
Raffuse, Tim S. Dye. Sonoma Technology, Inc. Petaluma, CA. WESTAR Fall
Business Meeting. Boise, ID. September 27, 2006
Ozone transport during the California Ozone Deposition Experiment. Jielun
Sun, William Massman. Journal of Geophysical research. Vol.104 , No. D10, Pages
11,939-11,948, May 27 1999.
Ozone trasport analysis using back-trajectories and CAMx probing Tools. Presented at
the 9th Annual CMAS Conference, Chapel Hill, NC, October 11-13, 2010
Thanks
Question