Christoffer P Nielsen

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A series of aggressive measures was launched by the Chinese government to reduce pollutant emissions from Beijing and surrounding areas during the Olympic Games. Observations at Miyun, a rural site 100 km downwind of the Beijing urban center, show significant decreases in concentrations of O 3 , CO, NO y , and SO 2 during August 2008, relative to August(More)
The uncertainties of a national, bottom-up inventory of Chinese emissions of anthropogenic SO 2 , NO x , and particulate matter (PM) of different size classes and carbona-ceous species are comprehensively quantified, for the first time, using Monte Carlo simulation. The inventory is struc-tured by seven dominant sectors: coal-fired electric power, cement,(More)
Emissions of air pollutants in East Asia play an important role in the regional and global atmospheric environment. In this study we evaluated the recent emission trends of sulfur dioxide (SO 2), nitrogen oxides (NO x), particulate matter (PM), and non-methane volatile organic compounds (NMVOC) in East Asia, and projected their future emissions up until(More)
We present a comprehensive analysis of salt transport and overlimiting currents in a microchannel during concentration polarization. We have carried out full numerical simulations of the coupled Poisson-Nernst-Planck-Stokes problem governing the transport and rationalized the behavior of the system. A remarkable outcome of the investigations is the(More)
To examine the efficacy of China's actions to control atmospheric pollution, three levels of growth of energy consumption and three levels of implementation of emission controls are estimated, generating a total of nine combined activity-emission control scenarios that are then used to estimate trends of national emissions of primary air pollutants through(More)
China's anthropogenic emissions of atmospheric mercury (Hg) are effectively constrained by national air pollution control and energy efficiency policies. In this study, improved methods, based on available data from domestic field measurements, are developed to quantify the benefits of Hg abatement by various emission control measures. Those measures(More)
China is experiencing severe carbonaceous aerosol pollution driven mainly by large emissions resulting from intensive use of solid fuels. To gain a better understanding of the levels and trends of carbonaceous aerosol emissions and the resulting ambient concentrations at the national scale, we update an emission inventory of anthropogenic organic carbon(More)
A sequence of 3 patches of high-density (10 12 m −3) cold plasma on a horizontal scale-size of 300– 700 km was observed near magnetic noon by the EISCAT VHF radar above Svalbard on 17 December 2001. The patches followed a trajectory towards the cusp inflow region. The combination of radar and all-sky observations demonstrates that the patches must have been(More)
To examine the effects of China's national policies of energy conservation and emission control during 2005– 2010, inter-annual emission trends of gaseous pollutants, primary aerosols, and CO 2 are estimated with a bottom-up framework. The control measures led to improved energy efficiency and/or increased penetration of emission control devices at power(More)
With most eastern Chinese cities facing major air quality challenges, there is a strong need for city-scale emission inventories for use in both chemical transport modeling and the development of pollution control policies. In this paper , a high-resolution emission inventory (with a horizontal resolution of 3 × 3 km) of air pollutants and CO 2 for Nanjing,(More)