Latest Pleistocene alpine glacier advances in the Sawtooth Mountains, Idaho, USA: Reflections of midlatitude moisture transport at the close of the last glaciation

Geology ◽  
2004 ◽  
Vol 32 (3) ◽  
pp. 225 ◽  
Author(s):  
Glenn D. Thackray ◽  
Kari A. Lundeen ◽  
Jennifer A. Borgert
2018 ◽  
Vol 31 (16) ◽  
pp. 6281-6297 ◽  
Author(s):  
Kelly Mahoney ◽  
Dustin Swales ◽  
Michael J. Mueller ◽  
Michael Alexander ◽  
Mimi Hughes ◽  
...  

Abstract Atmospheric rivers (ARs) are well-known producers of precipitation along the U.S. West Coast. Depending on their intensity, orientation, and location of landfall, some ARs penetrate inland and cause heavy rainfall and flooding hundreds of miles from the coast. Climate change is projected to potentially alter a variety of AR characteristics and impacts. This study examines potential future changes in moisture transport and precipitation intensity, type, and distribution for a high-impact landfalling AR event in the U.S. Pacific Northwest using an ensemble of high-resolution numerical simulations produced under projected future thermodynamic changes. Results indicate increased total precipitation in all future simulations, although there is considerable model spread in both domain-averaged and localized inland precipitation totals. Notable precipitation enhancements across inland locations such as Idaho’s Sawtooth Mountain Range are present in four out of six future simulations. The most marked inland precipitation increases are shown to occur by way of stronger and deeper moisture transport that more effectively crosses Oregon’s Coastal and Cascade mountain ranges, essentially “spilling over” into the Snake River Valley and fueling orographic precipitation in the Sawtooth Mountains. Moisture transport enhancements are shown to have both thermodynamic and dynamic contributions, with both enhanced absolute environmental moisture and localized lower- and midlevel dynamics contributing to amplified inland moisture penetration. Precipitation that fell as snow in the present-day simulation becomes rain in the future simulations for many mid- and high-elevation locations, suggesting potential for enhanced flood risk for these regions in future climate instances of similar events.


2016 ◽  
Author(s):  
Marta Vázquez ◽  
Raquel Nieto ◽  
Anita Drumond ◽  
Luis Gimeno

1997 ◽  
Vol 24 ◽  
pp. 288-292 ◽  
Author(s):  
Andrew P. Barrett ◽  
David N. Collins

Combined measurements of meltwater discharge from the portal and of water level in a borehole drilled to the bed of Findelengletscher, Switzerland, were obtained during the later part of the 1993 ablation season. A severe storm, lasting from 22 through 24 September, produced at least 130 mm of precipitation over the glacier, largely as rain. The combined hydrological records indicate periods during which the basal drainage system became constricted and water storage in the glacier increased, as well as phases of channel growth. During the storm, water pressure generally increased as water backed up in the drainage network. Abrupt, temporary falls in borehole water level were accompanied by pulses in portal discharge. On 24 September, whilst borehole water level continued to rise, water started to escape under pressure with a resultant increase in discharge. As the drainage network expanded, a large amount of debris was flushed from a wide area of the bed. Progressive growth in channel capacity as discharge increased enabled stored water to drain and borehole water level to fall rapidly. Possible relationships between observed borehole water levels and water pressures in subglacial channels are influenced by hydraulic conditions at the base of the hole, distance between the hole and a channel, and the nature of the substrate.


Sign in / Sign up

Export Citation Format

Share Document