A joint Fourier transform reflection absorption infrared spectroscopy/thermal programmed desorption (RAIRS/TPD) study has provided good evidence for the existence of protonated nitrosamide (NH3NO+) on surfaces at cold temperatures. This species has long been proposed to exist in studies of the DeNO(x) process and the decomposition of ammonium nitrite. In the context of the current experiments, performed at low-temperatures in the absence and presence of water-ice, the results provided a firm mechanistic basis for understanding the release of HONO from snowpack in a "dark" mechanism and also under alkaline surface conditions.