Glacial Hydrology and Landscape Evolution

We use various geochemical tracers to quantitatively constraint the sources of water in headwaters of the Himalayan Rivers. Our group is trying to improve existing and build new multi-component isotope and geochemical mixing models that could quantify the relative contributions of rainwater, glacial melt, snowmelt, and groundwater flow to the total discharge. We further focus on various types of chemical weathering reactions operating on the glacial catchment to understand the links between the atmospheric carbon dioxide (CO2) concentrations, glacial weathering, and the global carbon cycle.

Ongoing Projects

2021-2024 Himalayan metamorphic CO2 fluxes to the atmosphere: Solving the mystery behind a long-standing problem. (Principal Investigator, Science Education and Research Board, Government of India)
2018—2022 Integration of geochemical and hydrological modeling to quantify the present and future of Ganga River hydrology in the (Ministry of Earth Sciences, Government of India)

Completed Projects

2014—2017 Effects of climate change on cryosphere-river linkages: Insights from the seasonal and inter-annual variation of glacial melt discharge in the headwaters of the Ganges River (2014-Principal Investigator, Partnerships for enhanced engagement in research (PEER) Science, USA)

Selective Publications

2021 Shukla, T., ** Sen, I.S., Preparing for Floods on the Third Pole, Science, 372 (6539), 232-234, DOI: 10.1126/science.abh3558
2020 Shukla, T.,**, Sundriyal, S., Sen, I.S., Contemporary inorganic carbon fluxes from rapidly changing glacierized watersheds of the Himalaya, Journal of Hydrology, 587, 124972, https://doi.org/10.1016/j.jhydrol.2020.124972
2020 Boral, S.,* Sen, I.S., Tracing ‘Third Pole’ ice meltwater contribution to the Himalayan rivers using isotopes, Geochemical Perspectives Letters, 13, 48-53 doi: 10.7185/geochemlet.2013)
2018 Boral, S.,* Sen, I.S., Ghoshal, D., Peucker-Ehrenbrink, B., Hemingway, J. Stable water isotope modeling reveals spatio-temporal variability of glacier meltwater contributions to Ganges River headwaters. Journal of Hydrology, 577, 123983, https://doi.org/10.1016/j.jhydrol.2019.123983
2017 Hemingway, J. D,. Spencer, R. G. M., Podgorski, D. C., Zito, P., Sen, I. S., Galy,V. Glacier meltwater and monsoon precipitation drive Upper Ganges Basin dissolved organic matter composition. Geochimica et Cosmochimica Acta, 244, 216-228, https://doi.org/10.1016/j.gca.2018.10.012

Dust Provenance and Transport Mechanisms in High Mountains of Himalayas

Our group has recently (2015) installed PM10, PM2.5, and PM1 (particles less than 10, 205, and 1 μm in diameter) aerosol samplers at several locations including Kanpur, Harsil (remote village in Himalaya at 2500 m elevation) and Leh (Ladhak region) to understand the long distance transport and source of airborne particles in the Indo-Gangetic plains. We are using radioactive isotopes (Rb-Sr, Sm-Nd, U-Th-Pb, Re-Os) and trace element geochemistry in airborne particulate matters to understand their sources and pathways. The overarching goal is to combine aerosol geochemistry and atmospheric models to better understand atmospheric processes.

Completed Projects

2018—2021 Dust or soot? Tracing the primary drivers of increased glacial melt of the Himalayan glaciers (Principal Investigator, Department of Science and Technology, Government of India)
2014—2017 Integration of air mass trajectory models and 187Os/188Os isotope data to trace the long-range transport of atmospheric dust in India. (Principal Investigator, Science Education and Research Board, Government of India)

Selective Publications

2022 Nizam, S.,* Mitra, A.,* Shukla, T.,‡ Misra, S., Sen, I.S., Time-series record of platinum group elements in aerosols on the Himalaya reveals baseline concentration to judge future changes, Manuscript under consideration, Water Air and Soil Pollution Research, 233, 10, https://doi.org/10.1007/s11270-021-05478-5
2021 Nizam, S.,* Sen, I.S., Shukla, T., ** Selby, D., Melting of the Chhota Shigri Glacier, Western Himalaya, Insensitive to anthropogenic emission residues: Insights from geochemical evidence. Geophysical Research Letters, 48, 19, e2021GL092801, https://doi.org/10.1029/2021GL092801
2021 Mitra, A.,* Sen, I.S., Pandey, S. K., Vinoj, V., Reisberg, L., Bizimis, M., Cloquet, C., Nizam, S.* Lead isotope evidence for enhanced anthropogenic particle transport to the Himalayas during summer months, Environmental Science & Technology, 55(20), pp.13697-13708, https://doi.org/10.1021/acs.est.1c03830
2020 Nizam, S.,*, Sen, I.S., Vinoj, V., Galy, V., Selby, D., Azam, M.F., Pandey, S.K., Creaser, R.A., Agarwal, A.K., Singh, A.P., Bizimis, M. Biomass derived local organic carbon key to western Himalayan glacier melt, Environmental Science and Technology, 2020, 54, Issue 14; https://doi.org/10.1021/acs.est.0c02710 [FRONT COVER]

Large River Systems

We work on large river systems to better understand land-to-ocean connections, chemical evolution of dissolved and particulate load from source to sink, and groundwater-river water interactions. Presently all our research activities are focused in the Ganga and Mahanadi Rivers.

Ongoing Projects

2017-2022 Design and Development of Aquatic Autonomous Observatory (Niracara Svayamsasita VedhShala - NSVS) for In situ Monitoring, Real Time Data Transmission and Web based Visualization, co-PI, DST-IUSSTF

Selective Publications

2021 Boral, S.,* Peucker-Ehrenbrink, B., Hemingway, J.D., Sen, I.S., Galy, V., Fiske, G.J. Controls on short-term dissolved 87Sr/86Sr variations in large rivers: Evidence from the Ganga–Brahmaputra, Earth and Planetary Science Letters, 2021, 566, 116958, https://doi.org/10.1016/j.epsl.2021.116958
2021 Sen, I.S., Shukla, T., ** Boral, S., * Sharma, S., Time-series record during COVID-19 lockdown shows high resilience of dissolved heavy metals in the Ganga River, Environmental Science and Technology Letters, 2021 https://doi.org/10.1021/acs.estlett.0c00982 [FRONT COVER]
2020 Boral, S.,* Sen, I.S., Tripathi, A., Sharma, B., Dhar, S., Tracking dissolved trace elements in the Ganga River from source to sink: A baseline to judge future changes, Geochemistry, Geophysics, Geosystems, 21, e202 0GC009203. https://doi.org/10.1029/2020GC009203 [Research Spotlight]
2018 Sen, I.S., Boral, S., * Ranjan, S., ‡ Tandon, S.K., Small but important –The role of small floodplain tributaries to river nutrient budget, ACS Earth and Space Chemistry 2018, 2, 64-71, https://doi.org/10.1021/acsearthspacechem.7b00112