Journal ArticleDOI
Low and high NOx tropospheric photochemistry
Reads0
Chats0
TLDR
In this paper, the authors define two atmospheric states in terms of rates of NOx emissions and radical production: low NOx state, trace gas inputs to the atmosphere are removed primarily by oxidation reactions and high NOx states, the oxidative potential of the atmosphere is greatly diminished and primary pollutants build up, as alternate removal processes are slow.Abstract:
Emission inputs to the troposphere are processed in two fundamentally different ways, leading to two atmospheric states with greatly different properties. We define these states in terms of rates of NOx emissions and radical production. In the low NOx state, trace gas inputs to the atmosphere are removed primarily by oxidation reactions. In the high NOx state the oxidative potential of the atmosphere is greatly diminished and primary pollutants build up, as alternate removal processes are slow. We show here that this dual behavior is due to a titrationlike reaction between NOx and free radicals in which either reactant can be in excess.read more
Citations
More filters
Journal ArticleDOI
Radiative forcing of climate change
TL;DR: The authors reviewed the current understanding of mechanisms that are, or may be, acting to cause climate change over the past century, with an emphasis on those due to human activity, and discussed the general level of confidence in these estimates and areas of remaining uncertainty.
Journal ArticleDOI
The relation between ozone, NOx and hydrocarbons in urban and polluted rural environments
TL;DR: A review of insights derived from photochemical models and field measurements can be found in this paper, where the ozone-precursor relationship can be understood in terms of a fundamental split into a NOxsenstive and VOC-sensitive (or NOx-saturated) chemical regimes.
Journal ArticleDOI
Anthropogenic drivers of 2013–2017 trends in summer surface ozone in China
TL;DR: In this article, the effect of meteorological variability on ozone trends was investigated using a multiple linear regression model and the residual of this regression showed increasing ozone trends of 1-3 ppbv a−1 in megacity clusters of eastern China that they attributed to changes in anthropogenic emissions.
Journal ArticleDOI
Three-dimensional climatological distribution of tropospheric OH: Update and evaluation
C. M. Spivakovsky,Jennifer A. Logan,Stephen A. Montzka,Yves Balkanski,M. Foreman-Fowler,Dylan B. A. Jones,Larry W. Horowitz,Andrew C. Fusco,Carl A. M. Brenninkmeijer,Michael J. Prather,Steven C. Wofsy,Michael B. McElroy +11 more
TL;DR: A global climatological distribution of tropospheric OH is computed using observed distributions of O3, H2O, NOt (NO2 +NO + 2N2O5 + NO3 + HNO2+HNO4), CO, hydrocarbons, temperature, and cloud optical depth as discussed by the authors.
Journal ArticleDOI
The use of NO y , H2O2, and HNO3 as indicators for ozone‐NO x ‐hydrocarbon sensitivity in urban locations
TL;DR: In this article, a series of photochemical simulations with varying rates of anthropogenic and biogenic emissions and meteorology were used to evaluate the goodness of fit between model NOx-hydrocarbon sensitivity and indicator values.
References
More filters
Journal ArticleDOI
Tropospheric chemistry: A global perspective
TL;DR: A model for the photochemistry of the global troposphere constrained by observed concentrations of H2O, O3, CO, CH4, NO, NO2, and HNO3 is presented in this paper.
Journal ArticleDOI
Biogeochemical aspects of atmospheric methane
TL;DR: In this paper, the authors identify and evaluate several constraints on the budget of atmospheric methane, its sources, sinks and residence time, and construct a list of sources and sinks, identities, and sizes.
Journal ArticleDOI
Ozone production in the rural troposphere and the implications for regional and global ozone distributions
Shaw Chen Liu,Michael Trainer,Fred C. Fehsenfeld,David D. Parrish,Eric J. Williams,David W. Fahey,Gerhard Hübler,P. C. Murphy +7 more
TL;DR: The relationship between O3 and NOx (NO + NO2) which was measured during summer and winter periods at Niwot Ridge, Colorado, has been analyzed and compared to model calculations.
Journal ArticleDOI
Photodissociation in the atmosphere: 1. Actinic flux and the effects of ground reflections and clouds
TL;DR: In this paper, it was shown that photodissociation rate coefficients inside clouds, and particularly inside cloud droplets, can frequently exceed the clear-sky values, in contrast to current usage in cloud chemistry models, due to the ∼2 cos θ factor incurred in the actinic flux when the solar beam is scattered and diffused into nearly isotropic light.