Supporting information for Manuscript
Role of meteorological processes in ozone responses to emission
controls in California’s San Joaquin Valley
Ling Jin, Aurore Loisy, Nancy J Brown
Lawrence Berkeley National Laboratory, Berkeley, CA 94720
Corresponding author: Nancy J Brown, njbrown@lbl.gov, 510-486-4241
Submitted for consideration for publication in:
Journal of Geophysical Research
May 16, 2013
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Figure S1. 8-h ozone maxima (>75 ppb) peak time distribution. Note: The histogram cells are intervals of
the form ‘(a, b]’, i.e., they include their right-hand endpoint, but not their left one, with the exception of
the first cell which includes both right-hand and left-hand endpoint. Hour h indicates the 8-h range of [h-3,
h+4].
Forest Fires
SJV Key (cluster type from 1 to 6)
SFB Key (cluster type from 1 to 4)
SV Key (cluster type from 1 to 5)
Figure S2. Ozone cluster membership derived from Jin et al. (2011) with color qualitatively indicating the
average ozone levels.
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Historical ozone clusters derived from observational analysis
Investigators, who were part of the Central California Ozone Study (CCOS), conducted cluster
analysis of past ozone data (126 sites, from 1996 to 1998) based on the spatial patterns of several very
high ozone days selected by the local air quality districts (Fujita et al. 1999). Three clusters were
identified based on the 1996-1998 observational data: (1) the SFB has its highest basin-wide ozone, while
the SJV ozone is also very high, which is characterized by the weakest sea breeze; (2) the SJV has its
highest basin-wide ozone, while SFB and SV are relatively cleaner, which is characterized by a stronger
sea breeze, moving pollutants from SFB and SV to SJV; (3) SV has its highest basin-wide ozone values,
which, similar with the second cluster, has stronger sea breezes but higher temperature in the Sacramento
Valley; SJV ozone in this cluster is also high. Descriptions of these three historical ozone clusters match
respectively the model derived “O3-West”, “O3-South”, and “O3-North” ozone distributions together
with their associated meteorological conditions (see main text) in summer 2000.
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Spatial Characterization of the meteorological fields for the ozone episodes
Figure S3. Seasonal (June – September) average afternoon [11 AM, 6 PM] (a) temperature fields (K) and
(b) sea surface pressure (hPa).
O3-North
O3-South
O3-West
O3-North
Figure S4. Afternoon temperature anomalies (K) averaged over the four episodes (i.e. episode mean –
seasonal mean) with the resulting thermal gradients from low to high indicated by arrows for the first
three episodes.
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O3-North
O3-South
O3-West
O3-All
Figure S5. Afternoon sea surface pressure anomalies (hPa) averaged over the four episodes with arrows
(for the first three episodes) indicating prominent pressure gradients over the domain that can modify the
wind fields.
O3-North
O3-South
O3-West
O3-All
Figure S6. Afternoon wind anomaly fields averaged over the four ozone episodes indicating the wind
feature deviates from the seasonal mean. Wind speed (m/s) is color coded. Note seasonal mean is shown
in Figure 1 in the main text.
O3-North
O3-West
O3-South
O3-All
Figure S7. Average 500 mb geopotential heights (m). Data from NCEP reanalysis and the CCOS domain
is indicated by the inner square. Locations of the high pressure systems can be seen in the redder colors.
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1800
Number of grid cells
800
700
1600
North SJV
1400
800
700
Central SJV
600
600
1200
500
South SJV
500
1000
400
400
800
300
600
200
400
100
200
300
200
100
0
0
O3-North
O3-South
O3-West
O3-ALL
0
O3-North
O3-South
O3-West
O3-ALL
O3-North
O3-South
O3-West
O3-ALL
Figure S8. Ozone control options (as number of grid cells with afternoon 8-h ozone >75 ppb) for different
parts of SJV. Red-VOC control; Dark-blue-NOx; Light-blue-transition regime.
Figure S9. Afternoon OH concentrations (ppb) averaged for left: “O3-South” and right: “O3-ALL”
episodes.
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Differences in Ozone sensitivities (ppb) between the mAVOC case and OrigBase Case
Upper row: differences in O3 sensitivities to NOx;
Lower row: differences in O3 sensitivities to AVOC
O3-North
O3-North
O3-South
O3-West
O3-South
O3-West
O3-All
O3-All
Differences in Ozone sensitivities (ppb) between the mNOx case and OrigBase Case
Upper row: differences in O3 sensitivities to NOx;
Lower row: differences in O3 sensitivities to AVOC
O3-North
O3-North
O3-South
O3-West
O3-South
O3-West
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O3-All
O3-All
Differences in Ozone sensitivities (ppb) between the mBoth case and OrigBase Case
Upper row: differences in O3 sensitivities to NOx;
Lower row: differences in O3 sensitivities to AVOC
O3-North
O3-North
O3-South
O3-West
O3-South
O3-West
O3-All
O3-All
Figure S10. Differences in ozone sensitivities (ppb) between the alternative emission cases and the
OrigBase case for all episodes.
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100%
OrigBase
mAVOC
mNOx
75%
mBoth
50%
25%
0%
O3-North
O3-South
O3-West
O3-ALL
Figure S11. Percentage of high ozone grids in the SJV with VOC-control option (solid line) and with
NOx-control (dashed line) under different base case emissions for the four ozone episodes.
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mAVOC
mNOx
mBoth
O3-North
O3-North
O3-North
O3-South
O3-South
O3-South
O3-West
O3-West
O3-West
O3-All
O3-All
O3-All
Figure S12. Ozone control options under alternative base-case emissions (mapped at grid cells with
afternoon 8-h ozone level greater than 75 ppb): left column-mNOx, middle column-mAVOC, and right
column-mBoth. control options are color coded: Red-VOC control; Dark-blue-NOx; Light-blue-transition
regime. White indicates areas where the afternoon 8-hour average ozone does not exceed 75 ppb.
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Table S1. Changes in ozone exceedances (%) in the SJV under alternative emission cases relative to the
original base case.
O3-North
O3-South
O3-West
O3-All
mNOx
-12
-12
-7
-8
mAVOC
-14
-7
-10
-4
mBoth
-29
-18
-17
-13
References
Fujita, E., Keislar, R., Stockwell, W., Moosuller, H., DuBois, D., Koracin, D. and Zielinska, B. Central
California Ozone Study-Volume I, Field Study Plan. Division of Atmospheric Science Desert
Research Institue, 2215 Raggio Parkway, Reno, NV. 1999
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