We estimate the contamination risks from the atmospheric dispersion of radionuclides released by severe nuclear power plant accidents using the ECHAM/Modular Earth Submodel System (MESSy) atmospheric chemistry (EMAC) atmospheric chemistry-general circulation model at high resolution (50 km). We present an overview of global risks and also a case study of nuclear power plants that are currently ...

The study of organic chemistry in atmospheric aerosols and cloud formation is of interest in predictions of air quality and climate change. It is now known that aqueous phase chemistry is important in the formation of secondary organic aerosols. Here, the photoreactivity of pyruvic acid (PA; CH3COCOOH) is investigated in aqueous environments characteristic of atmospheric aerosols. PA is current...

[1] The magnitude and feedbacks of future methane release from the Arctic region are unknown. Despite limited documentation of potential future releases associated with thawing permafrost and degassing methane hydrates, the large potential for future methane releases calls for improved understanding of the interaction of a changing climate with processes in the Arctic and chemical feedbacks in ...

Methane (CH4) is the most abundant organic trace gas in the atmosphere. In the distant past, variations in natural sources of methane were responsible for trends in atmospheric methane levels recorded in ice cores. Since the 1700s, rapidly growing human activities, particularly in the areas of agriculture, fossil fuel use, and waste disposal, have more than doubled methane emissions. Atmospheri...

This paper provides an overview and summary of the current state of knowledge regarding critical atmospheric processes that affect the distribution and concentrations of greenhouse gases and aerosols emitted from wildland fires or produced through subsequent chemical reactions in the atmosphere. These critical atmospheric processes include the dynamics of plume rise, chemical reactions involvin...

Measurements of NO, NOy, N2O, and O3 during SPURT: implications for transport and chemistry in the lowermost stratosphere M. I. Hegglin, D. Brunner, Th. Peter, P. Hoor, H. Fischer, J. Staehelin, M. Krebsbach, C. Schiller, U. Parchatka, and U. Weers Institute for Atmospheric and Climate Science, Swiss Federal Institute of Technology, Zurich, Switzerland Max Planck Institute for Chemistry, Air Ch...

[1] A single-column chemistry and climate model has been used to study the impact of deforestation in the Amazon Basin on atmospheric chemistry. Over deforested areas, daytime ozone deposition generally decreases strongly except when surface wetness decreases through reduced precipitation, whereas nocturnal soil deposition increases. The isoprene and soil nitric oxide emissions decrease althoug...

1 Atmospheric Science Department, Colorado State University, Fort Collins, Colorado, USA 2 NOAA Earth System Research Laboratory, Boulder, Colorado, USA 3 CIRES, University of Colorado, Boulder, Colorado, USA School of Earth, Atmospheric and Environmental Sciences, University of Manchester, UK 5 Dept. Chemistry and Biochemistry, University of Colorado Boulder, Colorado, USA 6 Dept. of Atmospher...

Tropospheric ozone budget: regional and global calculations F. M. O’Connor, K. S. Law , J. A. Pyle, H. Barjat , N. Brough, K. Dewey, T. Green, J. Kent, and G. Phillips c NCAS-Atmospheric Chemistry Modelling Support Unit, Centre for Atmospheric Science, University of Cambridge, United Kingdom Centre for Atmospheric Science, University of Cambridge, United Kingdom Met. Research Flight, United Kin...

ACE is a Canadian satellite mission that will measure and help to understand the chemical and dynamical processes that control the distribution of ozone in the stratosphere. The ACE instruments are a Fourier transform infrared spectrometer, a UV/visible/near IR spectrograph and a two channel solar imager, all working in solar occultation mode.