Regional atmosphere chemical mechanisms

Chen, S., Brune, W.H., Oluwole, O.O., Kolb, C.E., Bacon, F., Li, G.Y., Rabitz, H. Global sensitivity analysis of the regional atmospheric chemical mechanism an application of random sampling-high dimensional model representation to urban oxidation chemistry. Environ. Sci. Technol. 46, 11162-11170 (2012)... 

The mechanism of the hydroxyl radical-initiated oxidation of /i-pincnc in the presence of NO has been investigated using a discharge-flow system. Propagation of hydroxyl radicals was observed after the addition of O2 and NO, and the measured concentration profiles were compared with simulations based on both the master chemical mechanism and the regional atmospheric chemistry mechanism for /i-pinene oxidation.228... 

Stockwell WR, Middleton P, Chang JS (1990) The second-generation regional acid deposition model chemical mechanism for regional atmospheric chemistry modelling. J Geophys Res 95 16343-16367... 

The continuous vaporization of cosmic dust in the upper atmosphere leads to permanent metal atom layers at altitudes between 90-100 km. As pointed out in the introduction, the metals play an important role in the lower regions of the ionospheric region (see Fig. 2). The first manifestation of upper atmospheric metals was noticed early this century, when coarse spectra of the night sky revealed a line at 589.2 nm. In 1929, Slipher suggested that this emission line was due to sodium.Later studies refined the measurement to 589.3 nm, and tne identification of the Na-D emission line was definitely made. Shortly after, the first association of the Na-D line emissions in the nightglow with meteors entering the Earth s atmosphere was made by a number of authors.The actual chemical mechanism that can lead to optical emission of the Na-D line was first suggested by Chapman" ... 

Very recently the photo-oxidation of HPALDs was incorporated into a detailed chemical mechanism and embedded into a global atmospheric model which generated higher levels of OH in better agreement with field measurements in pristine forested regions [45]. 

The chemical properties of the polymer surface will depend on the functional groups present on the surface and may depend on the vapor in contact with the surface. For example, the surface may be different if it has been in an inert atmosphere (argon, nitrogen) or in a water vapor-containing atmosphere. The mechanical properties of the surface region will depend on the amount and type of crosslinMng of the polymer material. Often the near-surface region of a polymer material has quite different mechanical properties from the bulk of the material. 

Patterson s friend Edward D. Goldberg at the Scripps Institution of Oceanography in La Jolla, California, had tipped him off that one of the best records of the world s climate is embedded in thin layers of glacial ice at high altitudes or near the poles. Snow, dust, and fog deposit chemicals from the atmosphere onto the ice, where they remain undisturbed for thousands of years. As Patterson quickly realized, Only the quiescent ice sheets in the arid, perpetually frozen polar regions of the Earth provide annual layers of precipitation that are undisturbed by percolation and mechanical mixing, that are relatively free of dusts and salts, and also are thin enough to be accessible even when centuries old. ... 

In addition to dissipation of the substance from the model system through degradation, other dissipative mechanisms can be considered. Neely and Mackay(26) and Mackay(3) have also introduced advection (loss of the chemical from the troposphere via diffusion) and sedimentation (loss of the chemical from dynamic regions of the system by movement deep into sedimentation layers). Both of these mechanisms are then assumed to act in the unit world. This approach makes it possible to investigate the behavior of atmosphere emissions where advection can be a significant process. Therefore, from a regulatory standpoint if the emission rate exceeds the advection rate and degradation processes in a system, accumulation of material could be expected. Based on such an analysis reduction of emissions would be called for. 

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