Research

Dr. Flowers is a glaciologist with interests in glacier and ice-sheet dynamics, the hydrology of glacierized systems and the relationship of these systems to climate. Her interests have led her to explore the hydrology and dynamics of alpine glaciers, outburst floods from ice-dammed lakes, glacier surges, glacier-climate interactions and the hydrology of paleo-ice masses. Field-based and modelling techniques complement one another in most of these pursuits. She currently leads a field-based glaciological research program in the St. Elias Mountains of Yukon, Canada, aimed at understanding the role of glacier dynamics in modulating regional glacier mass balance.

Currently/recently funded projects


St. Elias Field Project, Yukon
View toward Kaskawulsh Glacier, July 2006.
A fundamental problem in estimating climate-driven glacier change is in reliably quantifying the effect of climate on glacier mass balance. Further, the most reliable predictions of future climate come from coarsely resolved general circulation models, whose results have equivocal relationships with actual basin-scale meteorology. This field project is designed in part to quantify the basin-to-basin variability of glacier response to climate in an area subject to the same synoptic climate forcing. The project will begin with an environmental characterization of two neighbouring glaciers: determination of glacier geometry, mass balance, flow regime, surface meteorology and runoff characteristics, and move to integrating the resulting data into a hydrologically coupled glacier flowline model as well as spatially distributed basin-scale models. This project will be staged from the Kluane Lake Research Station operated by the Arctic Institute of North America.

Related publications:
  • MacDougall, A.H., B.A. Wheler and G.E. Flowers. 2011. A preliminary assessment of glacier melt-model parameter sensitivity and transferability in a dry subarctic environment. The Cryosphere, 5, 1011-1028. [pdf]
  • Flowers, G.E., N. Roux, S. Pimentel, C. Schoof. 2011. Present dynamics and future prognosis of a slowly surging glacier. The Cryosphere, 5, 299-313. [pdf]
  • MacDougall, A.H. and G.E. Flowers. 2011. Spatial and temporal transferability of a distributed energy-balance glacier melt-model. J. Clim., 24(5), 1480-1498. [pdf]
  • Wheler, B.A. and G.E. Flowers. 2011. Glacier subsurface heat-flux characterizations for energy balance modelling in the Donjek Range, southwest Yukon Territory, Canada. J. Glaciol. 57(201), 121-133. [pdf]
  • Mingo, L. and G.E. Flowers. 2010. Instruments and Methods: An integrated lightweight ice-penetrating radar system. J. Glaciol., 56(198), 709-714. [pdf]
  • De Paoli, L. and G.E. Flowers. 2009. Dynamics of a small surge-type glacier investigated using one-dimensional geophysical inversion. J. Glaciol., 55(194), 1101-1112. [pdf]
  • MacDougall, A.H. 2010. M.Sc. thesis, Simon Fraser University. [pdf, 11.5MB]
  • Wheler, B.A. 2009. M.Sc. thesis, Simon Fraser University. [pdf, 7.9MB]
  • De Paoli, L. 2009. M.Sc. thesis, Simon Fraser University. [pdf, 7.1MB]
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    Previous work

    Langjökull ice cap, central Iceland
    Field work on Langjökull ice cap, 2001.
    		Seismic studies and coring efforts in proglacial lake Hvítárvatn led by Áslaug Geirsdóttir (Science Institute, University of Iceland) and Gifford Miller (University of Colorado) have revealed a record diagnostic of shifting sediment delivery routes through the Holocene. The suggested glacial reconstruction points to rapid variability in the size and activity of Langjökull ice cap. To provide glaciologically realistic constraints on Langjökull's Holocene evolution as well as plausible Holocene maximum temperatures, we are using coupled models of ice dynamics and hydrology to explore the glacial history of the area.

    Related publications:
    • Flowers, G.E., H. Björnsson, Á. Geirsdóttir, G.H. Miller, J.L. Black and G.K.C. Clarke. 2008. Holocene climate conditions and glacier fluctuation in central Iceland from physical modelling and empirical evidence. Quat. Sci. Rev., 27, 797-813. [pdf]
    • Flowers, G.E., H. Björnsson, Á. Geirsdóttir, G.H. Miller and G.K.C. Clarke. 2007. Glacier fluctuation and inferred climatology of Langjökull ice cap through the Little Ice Age. Quat. Sci. Rev., 22, 2337-2353. [pdf]



    Vatnajökull ice cap, southeast Iceland

    In collaboration with Helgi Björnsson at the the Science Institute, University of Iceland, I worked on the spatial and temporal evolution of Vatnajökull ice cap hydrology as a postdoctoral project funded by the U.S. National Science Foundation. Our study focused on:
    NASA true colour image of Iceland, January,
    2002 (above). Landsat 1 MSS image of Vatna-
    jökull, courtesy of the USGS (below).


    		 1. Vatnajökull subglacial and periglacial hydrology. We used recently collected meteorological data, digital elevation models, and subsurface geological information to simulate Vatnajökull's present-day hydrology from source to sink. Special emphasis was on quantifying glacial discharge to the groundwater system, evaluating subglacial geothermal heat as a significant generator of melt water, and identifying the provenance of major outlet rivers.

    2. Glacier outburst flood (jökulhlaup) mechanics. Enormous glacier floods following the 1918 Katla eruption under Mýrdalsjökull ice cap and 1996 Gjálp eruption under Vatnajökull ice cap, Iceland, have discharge characteristics that cannot be explained by traditional jökulhlaup theory. We developed new conceptual and numerical models for these floods that help explain the propagation mechanisms that allow them to rapidly reach much higher discharges than other previously-studied jökulhlaups.

    3. Vatnajökull climate-change sensitivity. In collaboration with Shawn Marshall we simulated Vatnajökull's future geometry for various climate change scenarios over the next two centuries and evaluated the hydrological implications for southeast Iceland. Possible consequences include runoff repartitioning to major outlet rivers, disturbance of flood routing and frequency and decreased incidence of glacier surging.

    Related publications:
    • Marshall, S.J., H. Björnsson, G.E. Flowers and G.K.C. Clarke. 2005. Simulation of Vatnajökull ice cap dynamics. J. Geophys. Rev., 110, F03009, doi:10.1029/2004JF000262. [pdf]
    • Flowers, G.E., S.J. Marshall, H. Björnsson and G.K.C. Clarke. 2005. Sensitivity of Vatnajökull ice cap hydrology and dynamics to climate warming over the next two centuries. J. Geophys. Rev., 110, F02011, doi:10.1029/2004JF000200. [pdf]
    • Flowers, G.E., H. Björnsson, F. Pálsson and G.K.C. Clarke. 2004. A coupled sheet-conduit mechanism for jökulhlaup propagation. Geophys. Res. Lett., 31 L05401, doi:10.1029/2003GL019088. [pdf]
    • Flowers, G.E., H. Björnsson and F. Pálsson. 2003. New insights into the subglacial and periglacial hydrology of Vatnajökull, Iceland, from a distributed physical model. J. Glaciol., 49(165), 257-270. [pdf]
    • Björnsson, H., F. Pálsson, O. Sigurdsson and G.E. Flowers. 2003 Surges of glaciers in Iceland. Ann. Glaciol., 36, 82-90. [pdf]



    Trapridge Glacier, Yukon, Canada
    Trapridge Glacier and Mt. Wood (4842m, back-
    ground), Kluane Park Reserve, Yukon, Canada.
    Photo credit: Dan B. Stone.
    		As a doctoral student with Garry Clarke, I developed a multicomponent model of glacier hydrology that couples surface, internal, basal, and groundwater drainage. This work was broadly motivated by the need for a sound representation of basal hydrology that would eventually be incorporated into standard ice models. We applied this model to Trapridge Glacier (left), Yukon, Canada, where we collected optical and ice-penetrating radar data to create digital elevation models of the glacier surface and bed. Borehole studies at Trapridge Glacier provided records of subglacial hydromechanical phenomena on sub-hourly to seasonal time-scales, and were jointly used to refine model parameters and verify the merit of the model as an interpretive tool. This project was funded by the Natural Sciences and Engineering Research Council of Canada and was carried out with the support of the Arctic Institute of North America and Kluane Lake Research Station.
    Related publications:
    • Flowers, G.E. and G.K.C. Clarke. 2002. A multicomponent coupled model of glacier hydrology, 1, Theory and synthetic examples. J. Geophys. Res., 107(B11), 2287, doi:10.1029/2001JB001122. [pdf]
    • Flowers, G.E. and G.K.C. Clarke. 2002. A multicomponent coupled model of glacier hydrology, 2, Application to Trapridge Glacier, Yukon, Canada. J. Geophys. Res., 107(B11), 2288, doi:10.1029/2001JB001124. [pdf]
    • Flowers, G.E. 2000. Ph.D. thesis, University of British Columbia. [pdf, 10.2MB]
    • Flowers, G.E. and G.K.C. Clarke. 2000. An integrated modelling approach to understanding subglacial hydraulic release events. Ann. Glaciol., 31, 222-228. [pdf]
    • Flowers, G.E. and G.K.C. Clarke. 1999. Surface and bed topography of Trapridge Glacier, Yukon Territory, Canada: digital elevation models and derived hydraulic geometry. J. Glaciol., 45(149), 165-174. [pdf]