Chemical composition of freshsnow samples from the southern slope of Mt. Everest region (Khumbu-Himal region, Nepal)

In 1998 fresh surface snow samples were collected, no more than 2 days afte r the snowfall, along the Khumbu valley, and its lateral valleys (Kongmala and Changri Nup), at the end of the summer monsoon period. Samples from the Island Peak and Pumori slopes were also collected by climbers during pre- and post-monsoon season at altitudes ranging from 5300 to 6100 m a.s.l. Con ductivity, pH and major inorganic ions were measured in samples and relativ e field blanks. Chemical results were subjected to principal component anal ysis (PCA) in order to distinguish different sources of ions and study spat ial acid temporal distribution of ion concentrations. Two main factors, acc ounting For more than 80% of the total variance, were found. The two factor s were correlated to two different sources, one representing local transpor t and background contribution, and the other related to monsoon circulation . Concentrations of the main ions were compared to those measured in other remote areas, with particular regard to elevated areas in Central Asia. (C) 2001 Elsevier Science Ltd. AH rights reserved.