Irradiance at the ground

While most climate models consider feedbacks as being dependent on temperature (usually Ts), there are many other dependent variables in the climate system that could be involved, for example solar irradiance at the ground or rainfall. However, it is customary to describe these mathematically as functions of Tg,... 

ISO 9845-1, Solar energy - Reference solar spectral irradiance at the ground at different receiving conditions - Part 1 Direct normal and hemispherical solar irradiance for air mass 1,5 (available in English only), 1992. 

Solar energy reference solar spectral irradiance at the ground at different receiving conditions... 

Cycloadduct formation is not observed upon irradiation of t-1 with fumaronitrile, maleic anhydride, or tetracyanoethylene. Irradiation of t-1 and maleic anhydride results in the formation of an alternating copolymer (96). The radical-ion pair or free radical ions obtained upon irradiation of the charge-transfer complex in polar solvent are presumed to be the initiating species. Irradiation of the ground state complex of t-1 and tetracyanoethylene at 580 nm in solution or the solid state results in neither adduct formation or t-1 isomerization (76). Irradiation of t-1 at 313 nm in the presence of tetracyanoethylene results in rapid isomerization followed by slow but quantitative formation of phenanthrene and tetracyanoethane (97). Product formation is proposed to occur via a dark reaction of dihydrophenanthrene with the electron-poor alkene. 

Photochemical reactivity in the atmosphere can also involve compounds that are present on particulate matter or inside suspended water droplets in the upper layer of fog and cloud. Interestingly, because of radiation diffusion and reflection, the irradiation intensity on top of cloud can be double than at the ground [27]. 

Fig. 5.48 Spectral irradiance EBX J, of extraterrestrial solar radiation and Ex,a of direct solar radiation at the ground for a pure, cloudless atmosphere with mr l = 1-5. The curve indicated by rA,R-E A°n represents the attenuation caused by Rayleigh scattering alone. The dark areas indicate the absorption by each of the gases written on the graph (/io3 = 0.30 cm, w = 2.0cm)...

TPP)Fe(N0)(N02) in the metastable state following irradiation of the ground state isomer at low temperatures (see Section 2.3) (180). However, in anotherwork, Richter-Addo and coworkers succeeded in obtaining the crystal structure of the ferrous (d ) Mb (ONO) ( =photoreduced product) complex by photoreduction of the Mb (ONO) precursor (Equation 13) using a correlated microspectrophotometry and synchrotron X-ray (3 X 10 photons/s 2= 1.0 A) photoreduction technique at 100 K (273). 

It sometimes happens that a fluxional exchange process is suspected on chemical grounds but the low-temperature spectrum is seen at all accessible temperatures, and so the exchange is slow on the NMR timescale. An example is shown in Eq. 10.8, where we have to postulate exchange to account for the chemistry of the system, but it is too slow to affect the NMR lineshapes. In such circumstances, we can sometimes use spin saturation transfer. The principle of the method is to irradiate one of the resonances in the spectrum of one of the two species and watch for the effects on the spectrum of the other species. If we irradiate the MeA protons in 10.9a, we see a diminution in the intensity of the resonance for Meg in 10.9b. This shows that Mca in 10.9a becomes Mcb in 10.9b in the course of the exchange likewise, irradiation at the frequency of He affects the intensity of the Hd- In this way we can obtain mechanistic information about the fluxional process. 

By laser irradiation on Qg in the solution in which Cgg and TDAE are in equilibrium with the corresponding radical ions, other amounts of radical ions are generated photochemically, although the reaction system returns to thermal equilibrium by the back electron-transfer process. On combination of the back electron-transfer rate and the thermal equilibrium constant, the electron-transfer rate at the ground state can be estimated. For example, the rate constant of the electron-transfer process between Qg and TDAE in the ground state was estimated to be 6.4 x 10 s in o-dichlorobenzene, which is about 1/3 of the... 

With the resonance to the electronic transition, the ground-state population is partially depleted by the pump irradiation and restored with the time delay. The raw intensity of SH light was accordingly damped at fa = 0 and recovered in picoseconds, as seen in Figure 6.3a. Intensity modulation due to the vibrational coherence was superimposed on the non-modulated evolution as expected from Eq. (6.3). The coherence continued for picoseconds on this solution surface. The non-modulated component Isecond(fd> 2 ii) was fitted with a multiexponential... 

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