| Abstract | Over the past two decades, we observed a substantial rise in ionic content that was mainly determined by the sulfate concentration at 20 remote high elevation lakes located in central southern Himalaya. At LCN9, which was monitored on an annual basis for the last 20 years, the sulfate concentrations increased over 4-fold. Among the main causes, we exclude a change in the composition of wet atmospheric deposition, as well as a possible influence of decrease in seasonal snow cover duration, which could have exposed larger basin surfaces to alteration processes. Glacier retreat likely was the main factor responsible for the observed increase of sulfate concentrations. We attribute this chemical changes mainly to the sulfide oxidation processes that occur in subglacial environments. Moreover, we observe that the weakened monsoon of the past two decades has only partially contributed to the lakes enrichment through runoff waters that are more concentrated in solutes or lowering the water table, resulting in more rock exposed to air and enhanced mineral oxidation. |
| Text | 360184 2016 10.1021/acs.est.6b02735 Scopus 2 s2.0 84986005725 Climate change Water chemistry Snow Sagarmatha National Park Nepal Glacier melting increases the solute concentrations of himalayan glacial lakes Salerno F.; Rogora M.; Balestrini R.; Lami A.; Tartari G.A.; Thakuri S.; Godone D.; Freppaz M.; Tartari G. CNR Water Research Institute IRSA , Via del Mulino 19, Brugherio MB , 20861, Italy; CNR Institute of Ecosystem Study ISE , Largo Tonolli 50, Verbania Pallanza VB , 28922, Italy; Ev K2 CNR Committee, Via San Bernardino, 145, Bergamo, 24126, Italy; CNR IRPI Geohazard Monitoring Group, Strada delle Cacce, 73, Torino, 10135, Italy; Universita di Torino, DISAFA, NatRisk, Largo Paolo Braccini 2, Grugliasco TO , 10095, Italy Over the past two decades, we observed a substantial rise in ionic content that was mainly determined by the sulfate concentration at 20 remote high elevation lakes located in central southern Himalaya. At LCN9, which was monitored on an annual basis for the last 20 years, the sulfate concentrations increased over 4 fold. Among the main causes, we exclude a change in the composition of wet atmospheric deposition, as well as a possible influence of decrease in seasonal snow cover duration, which could have exposed larger basin surfaces to alteration processes. Glacier retreat likely was the main factor responsible for the observed increase of sulfate concentrations. We attribute this chemical changes mainly to the sulfide oxidation processes that occur in subglacial environments. Moreover, we observe that the weakened monsoon of the past two decades has only partially contributed to the lakes enrichment through runoff waters that are more concentrated in solutes or lowering the water table, resulting in more rock exposed to air and enhanced mineral oxidation. 50 Published version http //www.scopus.com/record/display.url eid=2 s2.0 84986005725 origin=inward Articolo acs_est_6b02735.pdf Articolo in rivista American Chemical Society, 0013 936X Environmental science technology Environmental science technology Environ. sci. technol. Environmental science technology. ES T Environmental science and technology THAKURI SUDEEP danilofrancescostefano.godone GODONE DANILO FRANCESCO STEFANO raffaella.balestrini BALESTRINI RAFFAELLA michela.rogora ROGORA MICHELA franco.salerno SALERNO FRANCO andrea.lami LAMI ANDREA gabriele.tartari TARTARI GABRIELE gianni.tartari TARTARI GIANNI TA.P05.010.001 Tecniche e tecnologie per il monitoraggio dei parametri che caratterizzano le evoluzioni morfologiche di alvei e versanti instabili. |
