Surface ozone-temperature relationships in the eastern US: A monthly climatology for evaluating chemistry-climate models
We use long-term, coincident O 3 and temperature measurements at the regionally representative US Environmental Protection Agency Clean Air Status and Trends Network (CASTNet) over the eastern US from 1988 through 2009 to characterize the surface O 3 response to year-to-year fluctuations in weather,...
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| Published in: | Atmospheric environment (1994) Vol. 47; pp. 142 - 153 |
|---|---|
| Main Authors: | , , , , , |
| Format: | Journal Article |
| Language: | English |
| Published: |
Kidlington
Elsevier Ltd
01.02.2012
Elsevier |
| Subjects: | |
| ISSN: | 1352-2310, 1873-2844 |
| Online Access: | Get full text |
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| Summary: | We use long-term, coincident O
3 and temperature measurements at the regionally representative US Environmental Protection Agency Clean Air Status and Trends Network (CASTNet) over the eastern US from 1988 through 2009 to characterize the surface O
3 response to year-to-year fluctuations in weather, for the purpose of evaluating global chemistry-climate models. We first produce a monthly climatology for each site over all available years, defined as the slope of the best-fit line (
m
O3-T) between monthly average values of maximum daily 8-hour average (MDA8) O
3 and monthly average values of daily maximum surface temperature (
T
max). Applying two distinct statistical approaches to aggregate the site-specific measurements to the regional scale, we find that summer time
m
O3-T is 3–6
ppb
K
−1 (
r
=
0.5–0.8) over the Northeast, 3–4
ppb
K
−1 (
r
=
0.5–0.9) over the Great Lakes, and 3–6
ppb
K
−1 (
r
=
0.2–0.8) over the Mid-Atlantic. The Geophysical Fluid Dynamics Laboratory (GFDL) Atmospheric Model version 3 (AM3) global chemistry-climate model generally captures the seasonal variations in correlation coefficients and
m
O3-T despite biases in both monthly mean summertime MDA8 O
3 (up to +10 to +30
ppb) and daily
T
max (up to +5
K) over the eastern US. During summer, GFDL AM3 reproduces
m
O3-T over the Northeast (
m
O3-T
=
2–6
ppb
K
−1;
r
=
0.6–0.9), but underestimates
m
O3-T by 4
ppb
K
−1 over the Mid-Atlantic, in part due to excessively warm temperatures above which O
3 production saturates in the model. Combining
T
max biases in GFDL AM3 with an observation-based
m
O3-T estimate of 3
ppb
K
−1implies that temperature biases could explain up to 5–15
ppb of the MDA8 O
3 bias in August and September though correcting for excessively cool temperatures would worsen the O
3 bias in June. We underscore the need for long-term, coincident measurements of air pollution and meteorological variables to develop process-level constraints for evaluating chemistry-climate models used to project air quality responses to climate change.
► We construct records of O
3-temperature relationships over the eastern US. ► Observed O
3-temperature relationships are used to evaluate a chemistry climate model. ► The model reproduces observed summer O
3 sensitivity to temperature over the Northeast. ► We find modeled temperature biases to partially explain excess-modeled summer O
3. ► Lasting long-term measurements are needed to support process-oriented model evaluation. |
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| Bibliography: | http://dx.doi.org/10.1016/j.atmosenv.2011.11.021 ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
| ISSN: | 1352-2310 1873-2844 |
| DOI: | 10.1016/j.atmosenv.2011.11.021 |