An endowed lecture series established by the late Professor Emeritus Harry S. Kieval to bring important and renowned speakers to the Humboldt State University campus to deliver a lecture on some popular and/or broad aspect of mathematics which would be attractive to undergraduates and to the public. The lectures are held once each fall and spring.
Fall 2009 Kieval Lecture
Kenneth M. Golden
Professor of Mathematics, University of Utah
Thursday, December 3, 2009
"Thermal Evolution of Fluid Permeability and Microstructure in Sea Ice "
at 7:30 PM, Location TBA
Sea ice is both an indicator and agent of climate change. It also hosts extensive algal and bacterial communities which sustain life in the polar oceans. The dramatic decline of the summer Arctic ice pack is perhaps the most visible, large scale change on Earth's surface in recent years. Most global climate models, however, have underestimated this decline, while the Antarctic sea ice pack has increased.
We will discuss some key sea ice processes which must be better represented in climate models, such as snow-ice formation and the evolution of melt ponds and ice pack reflectance. Recent advances in characterizing the porous microstructure of sea ice, and fluid flow through it, shed new light on these processes. Our work will help in predicting how global warming may affect sea ice, and the response of polar ecosystems. Video from a 2007 Antarctic expedition where we measured fluid and electrical transport in sea ice will be shown.Kenneth will also give the colloquium talk the same day (Thursday, December 3) at 4 p.m. in HGH 225.
""Thermal Evolution of Fluid Permeability and Microstructure in Sea Ice "
at 4 PM, HGH 225
Fluid fl ow through porous sea ice mediates a broad range of geophysical and biological processes such as snow-ice formation, the evolution of ice pack albedo, and nutrient replenishment for microbial communities living in brine inclusions. We will describe recent advances in using percolation, hierarchical, and network models to predict the uid permeability of sea ice, and rigorous di usion-based methods for bounding such transport coecients. We'll also discuss X-ray CT imaging of the brine microstructure and connectivity analysis of random graphs derived from the topographic images. Our work will help in predicting how global warming may a ect Earth's sea ice packs and how polar ecosystems may respond. Related results on electromagnetic properties will help in monitoring ice thickness and the impact of climate change on the polar marine environment.
This is a link to the HSU library video records of the Kieval Lectures.
Previous lecturers in this series have included: