Review of precipitation monitoring studies in India—a search for regional patterns

Abundance and distribution of gaseous ammonia and particulate ammonium at Delhi, India

“…In addition, the uncertainty in NH 3 estimation due 5026 S. Singh and U. C. Kulshrestha: Abundance and distribution of gaseous ammonia and particulate ammonium to the impinger technique can be reduced by using denuder technique where the NH 3 is trapped first and the remainder is captured on a filter (Sutton et al, 2001b). (Lenhard and Gravenhorst, 1980;Galloway et al, 1987;Galloway, 1988;Khemani et al, 1989;Possanzini et al, 1988;Tuncel and Unger, 1996;Parashar et al, 1996;Khare et al, 1996;Kulshrestha et al, 2005;Satyanarayana et al, 2010). But very few studies report NH 3 and NH + 4 in air (Table 1).…”

“…The soil dust, which is rich in CaCO 3 , is mainly contributed by resuspension of soils from the nearby Thar desert and open agricultural fields. The high dust content in the atmosphere is a typical feature of Indian continental region (Kulshrestha et al, 2005).…”

Chemical composition of rainwater at Maldives Climate Observatory at Hanimaadhoo (MCOH)

“…Table 8 shows that the annual cycle of wet deposition for most components observed is characterized by a maximum during the monsoon season (June-September) obviously associated with the maximum in rainfall amount during this season. The deposition of NH at MCOH are about a factor of three lower than the corresponding values given by Kulshrestha et al (2005) as median for rural sites in India. Substantially lower about a factor of two to five -annual wet deposition values for these three compounds have been reported from Amsterdam Island in the southern Indian Ocean (E. Baboukas, personal communication, 2000).…”

“…Such measurements also provide information on the input of anthropogenic and natural components to terrestrial, aquatic and marine ecosystems. Precipitation chemistry studies in the South Asian region have been carried out mainly in India (Kulshrestha et al, 1999(Kulshrestha et al, , 2005Granat et al, 2002;Mouli et al, 2005;Momin et al, 2005;Tiwari et al, 2007;Rastogi and Sarin, 2007;Salve et al, 2008;Budhavant et al, 2009). No systematic long-term measurements have been carried out previously in the Maldives or at other locations in the northern parts of the Indian Ocean.…”

“…A comparison with pH values measured in rain falling in the Indian subcontinent during winter season -e.g. typical values >6.0 at rural sites in India (Kulshrestha et al, 2005) -reveals that pH has a tendency to decrease as air is transported out over the Bay of Bengal and the Indian Ocean. The main reason is probably that the concentration of CaCO 3 from soil dust -which occurs mainly in the coarse particle mode, Granat et al (2010) -decreases more rapidly than the concentration of the acidifying components sulfuric and nitric acids of which at least the sulfuric acid is predominantly associated with the fine particle mode.…”