Dependence of Summertime Surface Ozone on NO x and VOC Emissions Over the United States: Peak Time and Value

2019 ◽  
Vol 46 (6) ◽  
pp. 3540-3550 ◽  
Author(s):  
Jianfeng Li ◽  
Yuhang Wang ◽  
Hang Qu
Keyword(s):  
United States ◽  
Surface Ozone ◽  
The United States ◽  
Peak Time ◽  
Voc Emissions

The importance of stratospheric–tropospheric transport in affecting surface ozone concentrations in the western and northern tier of the United States

2011 ◽  
Vol 45 (28) ◽  
pp. 4845-4857 ◽  
Author(s):  
Allen S. Lefohn ◽  
Heini Wernli ◽  
Douglas Shadwick ◽  
Sebastian Limbach ◽  
Samuel J. Oltmans ◽  
...  
Keyword(s):  
United States ◽  
Surface Ozone ◽  
The United States ◽  
Ozone Concentrations

Effects of ozone and climate on historical (1980-2015) crop yields in the United States: Implication for mid-21st century projection

2021 ◽  
Author(s):  
Yabin Da ◽  
Yangyang Xu ◽  
Bruce McCarl
Keyword(s):  
Climate Change ◽  
United States ◽  
Winter Wheat ◽  
Crop Yields ◽  
Time Window ◽  
Surface Ozone ◽  
The United States ◽  
Ozone Exposure ◽  
Future Climate Change ◽  
Ozone Pollution

<p>Surface ozone pollution has been proven to impose significant damages on crops. However, the quantification of the damages was extensively derived from chamber experiments, which is not representative of actual results in farm fields due to the limitations of spatial scale, time window, etc. In this work, we attempt to empirically fill this gap using county-level data in the United States from 1980 to 2015. We explore ozone impacts on corn, soybeans, spring wheat, winter wheat, barley, cotton, peanuts, rice, sorghum, and sunflower. We also incorporate a variety of climate variables to investigate potential ozone-climate interactions. More importantly, we shed light on future yield consequences of ozone and climate change individually and jointly under a moderate warming scenario. Our findings suggest significant negative impacts of ozone exposure for eight of the ten crops we examined, excepting barley and winter wheat, which contradicts experimental results. The average annual damages were estimated at $6.03 billion (in 2015 U.S. dollar) from 1980 to 2015. We also find rising temperatures tend to worsen ozone damages while water supply would mitigate that. Finally, elevated ozone driven by future climate change would cause much smaller damages than the direct effects of climate change itself.</p>

scholarly journals Impact of the 2008 Global Recession on air quality over the United States: Implications for surface ozone levels from changes in NOxemissions

2016 ◽  
Vol 43 (17) ◽  
pp. 9280-9288 ◽  
Author(s):  
Daniel Tong ◽  
Li Pan ◽  
Weiwei Chen ◽  
Lok Lamsal ◽  
Pius Lee ◽  
...  
Keyword(s):  
United States ◽  
Air Quality ◽  
Surface Ozone ◽  
The United States ◽  
Global Recession ◽  
Ozone Levels

scholarly journals CAM-chem: description and evaluation of interactive atmospheric chemistry in the Community Earth System Model

2012 ◽  
Vol 5 (2) ◽  
pp. 369-411 ◽  
Author(s):  
J.-F. Lamarque ◽  
L. K. Emmons ◽  
P. G. Hess ◽  
D. E. Kinnison ◽  
S. Tilmes ◽  
...  
Keyword(s):  
United States ◽  
Atmospheric Chemistry ◽  
Surface Ozone ◽  
The United States ◽  
Earth System Model ◽  
System Model ◽  
Ozone Production ◽  
Positive Bias ◽  
Earth System ◽  
Community Earth System Model

Abstract. We discuss and evaluate the representation of atmospheric chemistry in the global Community Atmosphere Model (CAM) version 4, the atmospheric component of the Community Earth System Model (CESM). We present a variety of configurations for the representation of tropospheric and stratospheric chemistry, wet removal, and online and offline meteorology. Results from simulations illustrating these configurations are compared with surface, aircraft and satellite observations. Major biases include a negative bias in the high-latitude CO distribution, a positive bias in upper-tropospheric/lower-stratospheric ozone, and a positive bias in summertime surface ozone (over the United States and Europe). The tropospheric net chemical ozone production varies significantly between configurations, partly related to variations in stratosphere-troposphere exchange. Aerosol optical depth tends to be underestimated over most regions, while comparison with aerosol surface measurements over the United States indicate reasonable results for sulfate , especially in the online simulation. Other aerosol species exhibit significant biases. Overall, the model-data comparison indicates that the offline simulation driven by GEOS5 meteorological analyses provides the best simulation, possibly due in part to the increased vertical resolution (52 levels instead of 26 for online dynamics). The CAM-chem code as described in this paper, along with all the necessary datasets needed to perform the simulations described here, are available for download at www.cesm.ucar.edu.

scholarly journals Effects of Future Climate and Biogenic Emissions Changes on Surface Ozone over the United States and China

2008 ◽  
Vol 47 (7) ◽  
pp. 1888-1909 ◽  
Author(s):  
Jin-Tai Lin ◽  
Kenneth O. Patten ◽  
Katharine Hayhoe ◽  
Xin-Zhong Liang ◽  
Donald J. Wuebbles
Keyword(s):  
United States ◽  
Spatial Patterns ◽  
Climate Changes ◽  
Surface Ozone ◽  
The United States ◽  
Department Of Energy ◽  
Biogenic Emissions ◽  
Climate Projections ◽  
Near Surface ◽  
Emissions Scenarios

Abstract Future projections of near-surface ozone concentrations depend on the climate/emissions scenario used to drive future simulations, the direct effects of the changing climate on the atmosphere, and the indirect effects of changing temperatures and CO2 levels on biogenic ozone precursor emissions. The authors investigate the influence of these factors on potential future changes in summertime daily 8-h maximum ozone over the United States and China by comparing Model for Ozone and Related Chemical Tracers, version 2.4, (MOZART-2.4) simulations for the period 1996–2000 with 2095–99, using climate projections from NCAR–Department of Energy Parallel Climate Model simulations driven by the Intergovernmental Panel on Climate Change Special Report on Emissions Scenarios A1fi (higher) and B1 (lower) emission scenarios, with corresponding changes in biogenic emissions. The effect of projected climate changes alone on surface ozone is generally less than 3 ppb over most regions. Regional ozone increases and decreases are driven mainly by local warming and marine air dilution enhancement, respectively. Changes are approximately the same magnitude under both scenarios, although spatial patterns of responses differ. Projected increases in isoprene emissions (32%–94% over both countries), however, result in significantly greater changes in surface ozone. Increases of 1–15 ppb are found under A1fi and of 0–7 ppb are found under B1. These increases not only raise the frequency of “high ozone days,” but are also projected to occur nearly uniformly across the distribution of daily ozone maxima. Thus, projected future ozone changes appear to be more sensitive to changes in biogenic emissions than to direct climate changes, and the spatial patterns and magnitude of future ozone changes depend strongly on the future emissions scenarios used.

scholarly journals Phenomenological Modelling of COVID-19 Epidemics in Sri Lanka, Italy, the United States, and Hebei Province of China

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
A. M. C. H. Attanayake ◽  
S. S. N. Perera ◽  
S. Jayasinghe
Keyword(s):  
United States ◽  
Sri Lanka ◽  
Growth Curves ◽  
The United States ◽  
Hebei Province ◽  
Disease Spread ◽  
Peak Time ◽  
Cumulative Number ◽  
Daily Growth ◽  
Epidemic Size

The COVID-19 pandemic has resulted in increasing number of infections and deaths every day. Lack of specialized treatments for the disease demands preventive measures based on statistical/mathematical models. The analysis of epidemiological curve fitting, on number of daily infections across affected countries, provides useful insights on the characteristics of the epidemic. A variety of phenomenological models are available to capture the dynamics of disease spread and growth. The number of daily new infections and cumulative number of infections in COVID-19 over four selected countries, namely, Sri Lanka, Italy, the United States, and Hebei province of China, from the first day of appearance of cases to 2nd July 2020 were used in the study. Gompertz, logistic, Weibull, and exponential growth curves were fitted on the cumulative number of infections across countries. AIC, BIC, RMSE, and R 2 were used to determine the best fitting curve for each country. Results revealed that the most appropriate growth curves for Sri Lanka, Italy, the United States, and China (Hebei) are the logistic, Gompertz, Weibull, and Gompertz curves, respectively. Country-wise, overall growth rate, final epidemic size, and short-term forecasts were evaluated using the selected model. Daily log incidences in each country were regressed before and after the identified peak time of the respective outbreak of epidemic. Hence, doubling time/halving time together with daily growth rates and predictions was estimated. Findings and relevant interpretations demonstrate that the outbreak seems to be extinct in Hebei, China, whereas further transmissions are possible in the United States. In Italy and Sri Lanka, current outbreaks transmit in a decreasing rate.

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