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Invited Talk DCCC, IISc


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Invited Talk DCCC, IISc
« on: September 17, 2018, 01:14:40 PM »

Dear All,

Divecha Centre for Climate Change

Indian Institute of Science


Guest Lecture



Speaker                      : Dr. Indra Sekhar Sen

                                        Assistant Professor

Department of Earth Sciences
Indian Institute of Technology, Kanpur


Title                             : Stable Water Isotope Modeling of Glacier Meltwater in Headwaters of the Hindu   Kush Himalayan Rivers: Variability in Space, Time and Possible Causes


Date & Time               : 19th September 2018 (Wednesday) & at 11.00 AM


Venue                         : Conference room (No. D305), Divecha Centre for Climate Change


Host                            : Dr. Anil V Kulkarni


Coffee/ Tea                 : at 10.45 AM



****All are cordially invited***


Abstract                      Himalayan headwater rivers are primarily sourced from glacier meltwater and from Indian summer monsoon (ISM) precipitation, both of which will be strongly influenced by ongoing and future climate change. Hydrologic modeling studies suggest that the glacier meltwater contribution is highest during the warm, dry pre-ISM months (April – June), but this hypothesis is currently hindered by a lack of observational data. To provide new spatial and temporal constraints on end-member contributions in Himalayan streams, we measured electrical conductivity and stable water isotopes (δ18O and δD) in nested catchments throughout the Upper Ganges Basin across three seasons (pre-ISM, ISM, post-ISM) over three years (2014 – 2016). For all time points, we observed a sharp depletion in δ18O and δD moving toward higher elevations, coincident with precipitation isotope trends. Using a site- and season-specific isotope mixing approach, our analyses further revealed large seasonal variability in end-member contributions throughout the basin. Surprisingly, glacier meltwater contributions were highest during the ISM (July – September) and post-ISM (October – December) seasons, contrary to previous model predictions. In addition to protracted storage of glacier meltwater in groundwater aquifers, this result supports "rain-induced" glacier melting during the ISM, which we show can produce 3 – 11 % of total discharge at the glacier snout. In conclusion, glacier meltwater contributions to Himalayan streams exhibit complex seasonal dynamics; this interpretation should be considered when predicting hydrologic responses to climate change in this region.


For more details          : or


Arya A.R

Divecha Centre for climate Change

Indian Institute of science

Thanks & Regards

Sonali Pattanayak
Research Associate
Divecha Center for Climate Change