Role of various water clusters in IR absorption in the 8–14-μm window region

A controversy exists over the cause of the IR absorption in the 8-14-microm wavelength window region. One explanation for the continuum absorption is to consider the accumulation of the far wings of strong water monomer absorption lines. On the other hand, other researchers believe that the IR absorption originates from the water dimer complex. Some other researchers claim that either water clusters of larger size or hydrated aerosols are responsible for the continuum absorption. Here we explore the hitherto less-understood systems of water clusters, both homomolecular and heteromolecular, including the water dimer, to enhance our knowledge of the cause of the IR absorption. The present study indicates that homomolecular water clusters larger than the dimer are not responsible for the continuum absorption.