Water effects on atmospheric reactions

Water has a very significant impact on the processes that occur in the Earth's atmosphere. Water is one the most abundant resources in our atmosphere and, because of its ability to be both a hydrogen bond donor and acceptor, it can form very stable complexes. The formation of these complexes can dramatically affect the chemistry in the atmosphere, including heterogeneous removal and alteration of the photochemical properties of the atmospheric species, the formation of water droplets and aerosol particles, as well as the participation of these complexes in chemical reactions. The total effects of water regarding all of these processes are not entirely known and need to be studied further. This review provides a comprehensive look at both the experimental and theoretical investigations of water vapour effects on gas phase reactions, with an emphasis on those pertinent to the atmosphere. The results discussed here provide an understanding of the fundamental concepts that lead to potential water effects, imparting a framework to realise the global effects of water in our atmosphere.