Surface ozone-temperature relationships in the eastern US: A monthly climatology for evaluating chemistry-climate models

2012 ◽  
Vol 47 ◽  
pp. 142-153 ◽  
Author(s):  
D.J. Rasmussen ◽  
A.M. Fiore ◽  
V. Naik ◽  
L.W. Horowitz ◽  
S.J. McGinnis ◽  
...  
Keyword(s):  
Climate Models ◽  
Surface Ozone

scholarly journals Regional responses of surface ozone in Europe to the location of high-latitude blocks and subtropical ridges

2016 ◽  
Author(s):  
Carlos Ordóñez ◽  
David Barriopedro ◽  
Ricardo García-Herrera ◽  
Pedro M. Sousa ◽  
Jordan L. Schnell
Keyword(s):  
High Latitude ◽  
Climate Models ◽  
Surface Ozone ◽  
Zonal Flow ◽  
Near Surface ◽  
Air Masses ◽  
Anticyclonic Circulation ◽  
The Uk ◽  
The Impact ◽  
First Time

Abstract. This paper analyses for the first time the impact of high-latitude blocks and subtropical ridges on near-surface ozone in Europe during a 15-year period. For this purpose, a catalogue of blocks and ridges over the Euro-Atlantic region is used together with a gridded dataset of maximum daily 8-hour running average ozone (MDA8 O3) covering the period 1998–2012. The response of ozone to the location of blocks and ridges with centres in three longitudinal sectors (Atlantic, ATL, 30º–0º W; European, EUR, 0º–30º E; Russian, RUS, 30º–60º E) is examined. The impact of blocks on ozone is regionally and seasonally dependent. In particular, blocks within the EUR sector yield positive ozone anomalies of ~ 5–10 ppb over large parts of central Europe in spring and northern Europe in summer. Over 20 % and 30 % of the days with blocks in that sector register exceedances of the 90th percentile of the seasonal ozone distribution at many European locations during spring and summer, respectively. The impacts of ridges during those seasons are subtle and more sensitive to their specific location, although they can trigger ozone anomalies of ~ 5–10 ppb in Italy and the surrounding countries in summer, eventually exceeding European air quality targets. During winter, surface ozone in the northwest of Europe presents completely opposite responses to blocks and ridges. The anticyclonic circulation associated with winter EUR blocking, and to a lesser extent with ATL blocking, yields negative ozone anomalies between −5 ppb and −10 ppb over the UK, Northern France and the Benelux. Conversely, the enhanced zonal flow around 50˚–60˚ N during the occurrence of ATL ridges favours the arrival of background air masses from the Atlantic and the ventilation of the boundary layer, producing positive ozone anomalies above 5 ppb in an area spanning from the British Isles to Germany. This work provides the first quantitative assessments of the remarkable but distinct impacts that the anticyclonic circulation and the diversion of the zonal flow associated with blocks and ridges exert on surface ozone in Europe. The findings reported here can be exploited in the future to evaluate the modelled responses of ozone to circulation changes within chemical transport models (CTMs) and chemistry-climate models (CCMs).

scholarly journals Use of North American and European air quality networks to evaluate global chemistry–climate modeling of surface ozone

2015 ◽  
Vol 15 (18) ◽  
pp. 10581-10596 ◽  
Author(s):  
J. L. Schnell ◽  
M. J. Prather ◽  
B. Josse ◽  
V. Naik ◽  
L. W. Horowitz ◽  
...  
Keyword(s):  
North America ◽  
Large Scale ◽  
Climate Models ◽  
Climate Modeling ◽  
Surface Ozone ◽  
Grid Cells ◽  
Current Generation ◽  
Annual Cycles ◽  
Diurnal Range ◽  
Model Measurement

Abstract. We test the current generation of global chemistry–climate models in their ability to simulate observed, present-day surface ozone. Models are evaluated against hourly surface ozone from 4217 stations in North America and Europe that are averaged over 1° × 1° grid cells, allowing commensurate model–measurement comparison. Models are generally biased high during all hours of the day and in all regions. Most models simulate the shape of regional summertime diurnal and annual cycles well, correctly matching the timing of hourly (~ 15:00 local time (LT)) and monthly (mid-June) peak surface ozone abundance. The amplitude of these cycles is less successfully matched. The observed summertime diurnal range (~ 25 ppb) is underestimated in all regions by about 7 ppb, and the observed seasonal range (~ 21 ppb) is underestimated by about 5 ppb except in the most polluted regions, where it is overestimated by about 5 ppb. The models generally match the pattern of the observed summertime ozone enhancement, but they overestimate its magnitude in most regions. Most models capture the observed distribution of extreme episode sizes, correctly showing that about 80 % of individual extreme events occur in large-scale, multi-day episodes of more than 100 grid cells. The models also match the observed linear relationship between episode size and a measure of episode intensity, which shows increases in ozone abundance by up to 6 ppb for larger-sized episodes. We conclude that the skill of the models evaluated here provides confidence in their projections of future surface ozone.

scholarly journals Impact of 2050 climate change on North American wildfire: consequences for ozone air quality

2015 ◽  
Vol 15 (17) ◽  
pp. 10033-10055 ◽  
Author(s):  
X. Yue ◽  
L. J. Mickley ◽  
J. A. Logan ◽  
R. C. Hudman ◽  
M. V. Martin ◽  
...  
Keyword(s):  
Air Quality ◽  
Climate Models ◽  
Transport Model ◽  
Surface Ozone ◽  
Chemical Transport Model ◽  
Activity Increase ◽  
Area Burned ◽  
Air Temperatures ◽  
Projected Changes ◽  
Almost All

Abstract. We estimate future area burned in the Alaskan and Canadian forest by the mid-century (2046–2065) based on the simulated meteorology from 13 climate models under the A1B scenario. We develop ecoregion-dependent regressions using observed relationships between annual total area burned and a suite of meteorological variables and fire weather indices, and apply these regressions to the simulated meteorology. We find that for Alaska and western Canada, almost all models predict significant (p < 0.05) increases in area burned at the mid-century, with median values ranging from 150 to 390 %, depending on the ecoregion. Such changes are attributed to the higher surface air temperatures and 500 hPa geopotential heights relative to present day, which together lead to favorable conditions for wildfire spread. Elsewhere the model predictions are not as robust. For the central and southern Canadian ecoregions, the models predict increases in area burned of 45–90 %. Except for the Taiga Plain, where area burned decreases by 50 %, no robust trends are found in northern Canada, due to the competing effects of hotter weather and wetter conditions there. Using the GEOS-Chem chemical transport model, we find that changes in wildfire emissions alone increase mean summertime surface ozone levels by 5 ppbv for Alaska, 3 ppbv for Canada, and 1 ppbv for the western US by the mid-century. In the northwestern US states, local wildfire emissions at the mid-century enhance surface ozone by an average of 1 ppbv, while transport of boreal fire pollution further degrades ozone air quality by an additional 0.5 ppbv. The projected changes in wildfire activity increase daily summertime surface ozone above the 95th percentile by 1 ppbv in the northwestern US, 5 ppbv in the high latitudes of Canada, and 15 ppbv in Alaska, suggesting a greater frequency of pollution episodes in the future atmosphere.

scholarly journals Climatological Characteristics of Arctic and Antarctic Surface-Based Inversions

2011 ◽  
Vol 24 (19) ◽  
pp. 5167-5186 ◽  
Author(s):  
Yehui Zhang ◽  
Dian J. Seidel ◽  
Jean-Christophe Golaz ◽  
Clara Deser ◽  
Robert A. Tomas
Keyword(s):  
Climate Models ◽  
Climate Model ◽  
Surface Ozone ◽  
Climatic Variability ◽  
Elevation Angle ◽  
Climate Feedback ◽  
The Arctic ◽  
Spatial And Temporal Variability ◽  
Seasonal And Diurnal Variations ◽  
Radiosonde Observation

Surface-based inversions (SBIs) are frequent features of the Arctic and Antarctic atmospheric boundary layer. They influence vertical mixing of energy, moisture and pollutants, cloud formation, and surface ozone destruction. Their climatic variability is related to that of sea ice and planetary albedo, important factors in climate feedback mechanisms. However, climatological polar SBI properties have not been fully characterized nor have climate model simulations of SBIs been compared comprehensively to observations. Using 20 years of twice-daily observations from 39 Arctic and 6 Antarctic radiosonde stations, this study examines the spatial and temporal variability of three SBI characteristic—frequency of occurrence, depth (from the surface to the inversion top), and intensity (temperature difference over the SBI depth)—and relationships among them. In both polar regions, SBIs are more frequent, deeper, and stronger in winter and autumn than in summer and spring. In the Arctic, these tendencies increase from the Norwegian Sea eastward toward the East Siberian Sea, associated both with (seasonal and diurnal) variations in solar elevation angle at the standard radiosonde observation times and with differences between continental and maritime climates. Two state-of-the-art climate models and one reanalysis dataset show similar seasonal patterns and spatial distributions of SBI properties as the radiosonde observations, but with biases in their magnitudes that differ among the models and that are smaller in winter and autumn than in spring and summer. SBI frequency, depth, and intensity are positively correlated, both spatially and temporally, and all three are anticorrelated with surface temperature.

scholarly journals Skill in forecasting extreme ozone pollution episodes with a global atmospheric chemistry model

2014 ◽  
Vol 14 (15) ◽  
pp. 7721-7739 ◽  
Author(s):  
J. L. Schnell ◽  
C. D. Holmes ◽  
A. Jangam ◽  
M. J. Prather
Keyword(s):  
Air Quality ◽  
Atmospheric Chemistry ◽  
Climate Models ◽  
Transport Model ◽  
Surface Ozone ◽  
The United States ◽  
Ozone Pollution ◽  
Mapping Algorithm ◽  
The Individual ◽  
Pollution Episodes

Abstract. From the ensemble of stations that monitor surface air quality over the United States and Europe, we identify extreme ozone pollution events and find that they occur predominantly in clustered, multiday episodes with spatial extents of more than 1000 km. Such scales are amenable to forecasting with current global atmospheric chemistry models. We develop an objective mapping algorithm that uses the heterogeneous observations of the individual surface sites to calculate surface ozone averaged over 1° by 1° grid cells, matching the resolution of a global model. Air quality extreme (AQX) events are identified locally as statistical extremes of the ozone climatology and not as air quality exceedances. With the University of California, Irvine chemistry-transport model (UCI CTM) we find there is skill in hindcasting these extreme episodes, and thus identify a new diagnostic using global chemistry–climate models (CCMs) to identify changes in the characteristics of extreme pollution episodes in a warming climate.

scholarly journals Skill in forecasting extreme ozone pollution episodes with a global atmospheric chemistry model

2014 ◽  
Vol 14 (5) ◽  
pp. 6261-6310 ◽  
Author(s):  
J. L. Schnell ◽  
C. D. Holmes ◽  
A. Jangam ◽  
M. J. Prather
Keyword(s):  
Air Quality ◽  
Atmospheric Chemistry ◽  
Climate Models ◽  
Transport Model ◽  
Surface Ozone ◽  
The United States ◽  
Ozone Pollution ◽  
Mapping Algorithm ◽  
The Individual ◽  
Pollution Episodes

Abstract. From the ensemble of stations that monitor surface air quality over the United States and Europe, we identify extreme ozone pollution events and find that they occur predominantly in clustered, multi-day episodes with spatial extents of more than 1000 km. Such scales are amenable to forecasting with current global atmospheric chemistry models. We develop an objective mapping algorithm that uses the heterogeneous observations of the individual surface sites to calculate surface ozone averaged over 1° by 1° grid cells, matching the resolution of a global model. Air quality extreme (AQX) events are identified locally as statistical extremes of the ozone climatology and not as air quality exceedances. With the University of California, Irvine chemistry-transport model (CTM) we find there is skill in hindcasting these extreme episodes, and thus identify a new diagnostic using global chemistry-climate models (CCM) to identify changes in the characteristics of extreme pollution episodes in a warming climate.

scholarly journals Regional responses of surface ozone in Europe to the location of high-latitude blocks and subtropical ridges

2017 ◽  
Vol 17 (4) ◽  
pp. 3111-3131 ◽  
Author(s):  
Carlos Ordóñez ◽  
David Barriopedro ◽  
Ricardo García-Herrera ◽  
Pedro M. Sousa ◽  
Jordan L. Schnell
Keyword(s):  
High Latitude ◽  
Western Europe ◽  
Climate Models ◽  
Linear Models ◽  
Surface Ozone ◽  
Zonal Flow ◽  
Near Surface ◽  
Anticyclonic Circulation ◽  
North West ◽  
The Impact

Abstract. This paper analyses for the first time the impact of high-latitude blocks and subtropical ridges on near-surface ozone (O3) in Europe during a 15-year period. For this purpose, a catalogue of blocks and ridges over the Euro–Atlantic region is used together with a gridded dataset of maximum daily 8 h running average ozone (MDA8 O3) covering the period 1998–2012. The response of ozone to the location of blocks and ridges with centres in three longitudinal sectors (Atlantic, ATL, 30–0° W; European, EUR, 0–30° E; Russian, RUS, 30–60° E) is examined. The impact of blocks on ozone is regionally and seasonally dependent. In particular, blocks within the EUR sector yield positive ozone anomalies of  ∼  5–10 ppb over large parts of central Europe in spring and northern Europe in summer. Over 20 and 30 % of the days with blocks in that sector register exceedances of the 90th percentile of the seasonal ozone distribution at many European locations during spring and summer, respectively. The impacts of ridges during those seasons are subtle and more sensitive to their specific location, although they can trigger ozone anomalies above 10 ppb in northern Italy and the surrounding countries in summer, eventually exceeding European air quality (AQ) targets. During winter, surface ozone in the north-west of Europe presents completely opposite responses to blocks and ridges. The anticyclonic circulation associated with winter EUR blocking, and to a lesser extent with ATL blocking, yields negative ozone anomalies between −5 and −10 ppb over the UK, northern France and the Benelux. Conversely, the enhanced zonal flow around 50–60° N during the occurrence of ATL ridges favours the arrival of background air masses from the Atlantic and the ventilation of the boundary layer, producing positive ozone anomalies of  ∼  5 ppb in an area spanning from the British Isles to the northern half of Germany. We also show that multiple linear models on the seasonal frequency of occurrence of these synoptic patterns can explain a considerable fraction of the interannual variability in some winter and summer ozone statistics (mean levels and number of exceedances of the 90th percentile) over some regions of western Europe. Thus, this work provides the first quantitative assessments of the remarkable but distinct impacts that the anticyclonic circulation and the diversion of the zonal flow associated with blocks and ridges exert on surface ozone in Europe. The findings reported here can be exploited in the future to evaluate the modelled responses of ozone to circulation changes within chemical transport models (CTMs) and chemistry–climate models (CCMs).

scholarly journals Representing ozone extremes in European megacities: the importance of resolution in a global chemistry climate model

2014 ◽  
Vol 14 (8) ◽  
pp. 3899-3912 ◽  
Author(s):  
Z. S. Stock ◽  
M. R. Russo ◽  
J. A. Pyle
Keyword(s):  
Atmospheric Chemistry ◽  
Urban Areas ◽  
Climate Models ◽  
Climate Model ◽  
Surface Ozone ◽  
Global Climate Models ◽  
Ozone Concentrations ◽  
Coarse Resolution ◽  
Highly Nonlinear ◽  
The Impact

Abstract. The continuing growth of the world's urban population has led to an increasing number of cities with more than 10 million inhabitants. The higher emissions of pollutants, coupled to higher population density, makes predictions of air quality in these megacities of particular importance from both a science and a policy perspective. Global climate models are typically run at coarse resolution to enable both the efficient running of long time integrations, and the ability to run multiple future climate scenarios. However, when considering surface ozone concentrations at the local scale, coarse resolution can lead to inaccuracies arising from the highly nonlinear ozone chemistry and the sensitivity of ozone to the distribution of its precursors on smaller scales. In this study, we use UM-UKCA, a global atmospheric chemistry model, coupled to the UK Met Office Unified Model, to investigate the impact of model resolution on tropospheric ozone, ranging from global to local scales. We focus on the model's ability to represent the probability of high ozone concentrations in the summer and low ozone concentrations, associated with polluted megacity environments, in the winter, and how this varies with horizontal resolution. We perform time-slice integrations with two model configurations at typical climate resolution (CR, ~150 km) and at a higher resolution (HR, ~40 km). The CR configuration leads to overestimation of ozone concentrations on both regional and local scales, while it gives broadly similar results to the HR configuration on the global scale. The HR configuration is found to produce a more realistic diurnal cycle of ozone concentrations and to give a better representation of the probability density function of ozone values in urban areas such as the megacities of London and Paris. We find the observed differences in model behaviour between CR and HR configurations to be largely caused by chemical differences during the winter and meteorological differences during the summer.

scholarly journals Long-term trends of surface ozone and its influencing factors at the Mt Waliguan GAW station, China – Part 1: Overall trends and characteristics

2016 ◽  
Vol 16 (10) ◽  
pp. 6191-6205 ◽  
Author(s):  
Wanyun Xu ◽  
Weili Lin ◽  
Xiaobin Xu ◽  
Jie Tang ◽  
Jianqing Huang ◽  
...  
Keyword(s):  
Influencing Factors ◽  
Climate Models ◽  
Surface Ozone ◽  
Western China ◽  
Trend Test ◽  
Environment Change ◽  
Atmospheric Pollutant ◽  
Mountain Valley ◽  
Long Term Trends

Abstract. Tropospheric ozone is an important atmospheric oxidant, greenhouse gas and atmospheric pollutant at the same time. The oxidation capacity of the atmosphere, climate, human and vegetation health can be impacted by the increase of the ozone level. Therefore, long-term determination of trends of baseline ozone is highly needed information for environmental and climate change assessment. So far, studies on the long-term trends of ozone at representative sites are mainly available for European and North American sites. Similar studies are lacking for China and many other developing countries. Measurements of surface ozone were carried out at a baseline Global Atmospheric Watch (GAW) station in the north-eastern Tibetan Plateau region (Mt Waliguan, 36°17′ N, 100°54′ E, 3816 m a.s.l.) for the period of 1994 to 2013. To uncover the variation characteristics, long-term trends and influencing factors of surface ozone at this remote site in western China, a two-part study has been carried out, with this part focusing on the overall characteristics of diurnal, seasonal and long-term variations and the trends of surface ozone. To obtain reliable ozone trends, we performed the Mann–Kendall trend test and the Hilbert–Huang transform (HHT) analysis on the ozone data. Our results confirm that the mountain-valley breeze plays an important role in the diurnal cycle of surface ozone at Waliguan, resulting in higher ozone values during the night and lower ones during the day, as was previously reported. Systematic diurnal and seasonal variations were found in mountain-valley breezes at the site, which were used in defining season-dependent daytime and nighttime periods for trend calculations. Significant positive trends in surface ozone were detected for both daytime (0.24 ± 0.16 ppbv year−1) and nighttime (0.28 ± 0.17 ppbv year−1). The largest nighttime increasing rate occurred in autumn (0.29 ± 0.11 ppbv year−1), followed by spring (0.24 ± 0.12 ppbv year−1), summer (0.22 ± 0.20 ppbv year−1) and winter (0.13 ± 0.10 ppbv year−1), respectively. The HHT spectral analysis identified four different stages with different positive trends, with the largest increase occurring around May 2000 and October 2010. The HHT results suggest that there were 2–4a, 7a and 11a periodicities in the time series of surface ozone at Waliguan. The results of this study can be used for assessments of climate and environment change and in the validation of chemistry–climate models.

scholarly journals Impact of 2050 climate change on North American wildfire: consequences for ozone air quality

2015 ◽  
Vol 15 (9) ◽  
pp. 13867-13921
Author(s):  
X. Yue ◽  
L. J. Mickley ◽  
J. A. Logan ◽  
R. C. Hudman ◽  
M. Val Martin ◽  
...  
Keyword(s):  
Air Quality ◽  
Climate Models ◽  
Transport Model ◽  
Surface Ozone ◽  
Chemical Transport Model ◽  
Activity Increase ◽  
Area Burned ◽  
Air Temperatures ◽  
Projected Changes ◽  
Almost All

Abstract. We estimate future area burned in Alaskan and Canadian forest by the midcentury (2046–2065) based on the simulated meteorology from 13 climate models under the A1B scenario. We develop ecoregion-dependent regressions using observed relationships between annual total area burned and a suite of meteorological variables and fire weather indices, and apply these regressions to the simulated meteorology. We find that for Alaska and western Canada almost all models predict significant (p < 0.05) increases in area burned at the midcentury, with median values ranging from 150 to 390%, depending on the ecoregion. Such changes are attributed to the higher surface air temperatures and 500 hPa geopotential heights relative to present day, which together lead to favorable conditions for wildfire spread. Elsewhere the model predictions are not as robust. For the central and southern Canadian ecoregions, the models predict increases in area burned of 45–90%. Except for the Taiga Plain, where area burned decreases by 50%, no robust trends are found in northern Canada, due to the competing effects of hotter weather and wetter conditions there. Using the GEOS-Chem chemical transport model, we find that changes in wildfire emissions alone increase mean summertime surface ozone levels by 5 ppbv for Alaska, 3 ppbv for Canada, and 1 ppbv for the western US by the midcentury. In the northwestern US states, local wildfire emissions at midcentury enhance surface ozone by an average of 1 ppbv, while transport of boreal fire pollution further degrades ozone air quality by an additional 0.5 ppbv. The projected changes in wildfire activity increase daily summertime surface ozone above the 95th percentile by 1 ppbv in the northwestern US, 5 ppbv in the high latitudes of Canada, and 15 ppbv in Alaska, suggesting a greater frequency of pollution episodes in the future atmosphere.

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