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Full-Text Articles in Glaciology

Topographic Control Of Asynchronous Glacial Advances: A Case Study From Annapurna, Nepal, Beth Pratt-Sitaula, Douglas W. Burbank, Arjun M. Heimsath, Neil F. Humphrey, Michael Oskin, Jaakko Putkonen Dec 2011

Topographic Control Of Asynchronous Glacial Advances: A Case Study From Annapurna, Nepal, Beth Pratt-Sitaula, Douglas W. Burbank, Arjun M. Heimsath, Neil F. Humphrey, Michael Oskin, Jaakko Putkonen

All Faculty Scholarship for the College of the Sciences

Differences in the timing of glacial advances, which are commonly attributed to climatic changes, can be due to variations in valley topography. Cosmogenic 10Be dates from 24 glacial moraine boulders in 5 valleys define two age populations, late-glacial and early Holocene. Moraine ages correlate with paleoglacier valley hypsometries. Moraines in valleys with lower maximum altitudes date to the lateglacial, whereas those in valleys with higher maximum altitudes are early Holocene. Two valleys with similar equilibrium-line altitudes (ELAs), but contrasting ages, are < 5 km apart and share the same aspect, such that spatial differences in climate can be excluded. A glacial mass-balance cellular automata model of these two neighboring valleys predicts that change from a cooler-drier to warmer-wetter climate (as at the Holocene onset) would lead to the glacier in the higher altitude catchment advancing, while the lower one retreats or disappears, even though the ELA only shifted by ~120 m.


Recent Increase In Black Carbon Concentrations From A Mt. Everest Ice Core Spanning 1860–2000 Ad, S. D. Kaspari, M. Schwikowski, M. Gysel, M. G. Flanner, Kang Shichang, S. Hou, Paul A. Mayewski Feb 2011

Recent Increase In Black Carbon Concentrations From A Mt. Everest Ice Core Spanning 1860–2000 Ad, S. D. Kaspari, M. Schwikowski, M. Gysel, M. G. Flanner, Kang Shichang, S. Hou, Paul A. Mayewski

Climate Change Institute Faculty Scholarship

A Mt. Everest ice core spanning 1860–2000 AD and analyzed at high resolution for black carbon (BC) using a Single Particle Soot Photometer (SP2) demonstrates strong seasonality, with peak concentrations during the winter-spring, and low concentrations during the summer monsoon season. BC concentrations from 1975–2000 relative to 1860–1975 have increased approximately threefold, indicating that BC from anthropogenic sources is being transported to high elevation regions of the Himalaya. The timing of the increase in BC is consistent with BC emission inventory data from South Asia and the Middle East, however since 1990 the ice core BC record does not indicate …


Detection Of The Timing And Duration Of Snowmelt In The Hindu Kush-Himalaya Using Quikscat, 2000-2008, Prajjwal K. Panday, Karen E. Frey, Bardan Ghimire Jan 2011

Detection Of The Timing And Duration Of Snowmelt In The Hindu Kush-Himalaya Using Quikscat, 2000-2008, Prajjwal K. Panday, Karen E. Frey, Bardan Ghimire

Geography

The Hindu Kush-Himalayan (HKH) region holds the largest mass of ice in Central Asia and is highly vulnerable to global climate change, experiencing significant warming (0.21 ± 0.08 °C/decade) over the past few decades. Accurate monitoring of the timing and duration of snowmelt across the HKH region is important, as this region is expected to experience further warming in response to increased greenhouse gas forcing. Despite the many advantages and applications of satellite-derived radar scatterometer data shown for capturing ice and snow melt dynamics at high latitudes, similar comprehensive freeze/thaw detection studies at lower latitudes (including the HKH region) are …