The intermediate LIF spectra were observed and compared in the NO2 (lambda(exc)> 400 nm) and ClONO2 (lambda(exc)=308 nm) photolyses. Both spectra could be assigned to the same transient. Transient fluorescence spectra were recorded in the 12 500-16 400 cm(-1) range at lambda(exc)=436.45 nm. Analysis shows that the observed intermediate spectra can be attributed to the NO3 radical. The NO3 lifetime variations in the presence of CF4, CF3Cl, CF2Cl2, CFCl3, and CCl4 were also studied. It was shown that these compounds only influence the photolysis yield of NO3, without affecting its lifetime. The magnetic field influence on the discrete and total NO2 fluorescence, and on the NO3 radical yield were also measured using lambda(exc)=436.45, 458.13, 478.93, and 489.12 nm.