HIGH-RESOLUTION SPECTROSCOPY OF NITROUS ACID (HONO) AND ITS DEUTERATED SPECIES (DONO) IN THE FAR- AND MID-INFRARED REGIONS

Author Institution: Laboratoire Interuniversitaire des Systemes Atmospheriques (LISA), CNRS and Universites Paris-7 et -12, Creteil, FranceNitrous acid (HONO) is an important source for OH radicals in tropospheric photochemistry.} Currently it is measured in the atmosphere using its ultraviolet absorption bands} but it has also been detected in the mid-infrared spectral region using a tuneable diode-laser.} In order to complete and extend previous laboratory work on the infrared fundamental bands of {\it trans}-HONO} and {\it cis}-HONO} and also of its deuterated species (DONO)} we have carried out a number of new spectroscopic studies, focusing on \begin{itemize} \item{the first high-resolution spectra of {\it trans-} and {\it cis-}HONO and -DONO in the far-infrared region (30--120 cm$^{-1}$),} \item{the first high-resolution spectra and analysis of the $\nu_1$ bands of {\it trans-} and {\it cis-}DONO around 2600 cm$^{-1}$,} \item{new high-resolution spectra and analysis of the Coriolis-interacting $\nu_5$ and $\nu_6$ bands of HONO around 600 cm$^{-1}$.}} \end{itemize} In this talk we will present the main results and some comparisons with previous studies