In this chapter we are concerned with the mechanisms of organic photochemical reactions. Two important features of mechanisms are the correlation of molecular structure with reactivity and the investigation and establishment of the details of the elementary steps involved in a photochemical process as *R proceeds to P. We shall be concerned with the experimental tools for characterizing the str...

This study employs the regional Community Multiscale Air Quality (CMAQ) model to examine seasonal and diurnal variations of boundary layer ozone (O3) over East Asia. We evaluate the response of model simulations of boundary layer O3 to the choice of chemical mechanisms, meteorological fields, boundary conditions, and model resolutions. Data obtained from surface stations, aircraft measurements,...

We present an efficient method for the simulation of time-resolved photoelectron imaging (TRPEI) spectra in polyatomic molecules. Our approach combines trajectory-based molecular dynamics that account for non-adiabatic effects using surface hopping, with an approximate treatment of the photoionization process using Dyson orbitals as initial and Coulomb waves as final electron states. The method...

O3 is the major component of photochemical oxidants and gives rise to visible injuries on plant leaves. In O3-exposed plants, O2- is produced before the formation of the injury, but the role that O2- plays in plant response to 03 exposure is still unknown. To clarify its role, we observed the behavior of plants during O3 exposure after pretreatment with tiron, which is an O2- scavenger. When ti...

With the present theoretical study of the photochemical switching of E-methylfurylfulgide we contribute an important step towards the understanding of the photochemical processes in furylfulgide-related molecules. We have carried out large-scale, full-dimensional direct semiempirical configuration-interaction surface-hopping dynamics of the photoinduced ring-closure reaction. Simulated static a...

To clarify the relationship between changes in photochemical oxidants’ (Ox) concentrations and their precursors Kawasaki, a series of analyses were conducted using data on Ox, precursors, nitrogen oxides (NOx) volatile organic compounds (VOCs), meteorology that had been monitored throughout city Kawasaki for 30 years from 1990 to 2019. The trend air temperature was upward, wind speed downward, ...

Photochemical oxidants Cprimarily ozone) a s a i r po l lu tan ts pose a more ser ious problem t o f o r e s t s of t he United S t a t e s than any o ther s ing le a i r po l lu tan t . Temperate and Mediterraean fo r e s t s elsewhere have most l i k e l y been s imi l a r l y impacted and current inves t iga t ions of such e f f e c t s a re being pursued. Ozone Land i t s photochemically re...