“…They were reported in the urban (Kawamura and Ikushima, 1993;Sempéré and Kawamura, 1994;Rohrl and Lammel, 2001;Wang et al, 2002;Yao et al, 2002;Rompp et al, 2006;Kitanovski et al, 2011), mountainous (Legrand et al, 2007), marine (Kawamura and Sakaguchi, 1999;Mochida et al, 2003a, b), and Arctic and Antarctic atmospheres (Kawamura et al, 1996a(Kawamura et al, , b, 2005Narukawa et al, 2002Narukawa et al, , 2003. Due to their water-soluble properties, diacids as well as ketoacids and α-dicarbonyls can act as cloud condensation nuclei (CCN) and hence influence the Earth's radiative forcing and climate (Kawamura and Usukura, 1993;Saxena et al, 1995;Saxena and Hildemann, 1996).…”