A Dynamic Physical Model For Soil Temperature And Water In Taylor Valley, Antarctica, 2010 Colorado State University - Fort Collins
A Dynamic Physical Model For Soil Temperature And Water In Taylor Valley, Antarctica, H. W. Hunt, Andrew G. Fountain, Peter T. Doran, Hassan J. Basagic
Geography Faculty Publications and Presentations
We developed a simulation model for terrestrial sites including sensible heat exchange between the atmosphere and ground surface, inter- and intra-layer heat conduction by rock and soil, and shortwave and longwave radiation. Water fluxes included snowmelt, freezing/thawing of soil water, soil capillary flow, and vapour flows among atmosphere, soil, and snow. The model accounted for 96-99% of variation in soil temperature data. No long-term temporal trends in soil temperature were apparent. Soil water vapour concentration in thawed surface soil in summer often was higher than in frozen deeper soils, leading to downward vapour fluxes. Katabatic winds caused a reversal ...
An Investigation Of The Oceanic Redistribution Of Carbon During The Last Deglaciation, 2010 University of Colorado, Boulder
An Investigation Of The Oceanic Redistribution Of Carbon During The Last Deglaciation, Sean Patrick Bryan
Geological Sciences Graduate Theses & Dissertations
Records from ice and marine sediment cores have revealed significant changes in the
ocean and atmospheric carbon reservoirs at the end of the last glacial period: atmospheric CO2 concentrations increased by ~50%, the atmospheric radiocarbon activity (Δ14C) declined by 190‰, the Δ14C of intermediate depth waters in the eastern North Pacific Ocean became extremely low relative to the contemporaneous atmosphere, and planktic foraminifera in the tropical and southern high latitude oceans experienced a negative excursion in δ13C. A promising theory for explaining these changes involves increased storage of carbon in the deep ocean during ...
Post-Coring Entrapment Of Modern Air In Some Shallow Ice Cores Collected Near The Firn-Ice Transition: Evidence From Cfc-12 Measurements In Antarctic Firn Air And Ice Cores, 2010 University of California - Irvine
Post-Coring Entrapment Of Modern Air In Some Shallow Ice Cores Collected Near The Firn-Ice Transition: Evidence From Cfc-12 Measurements In Antarctic Firn Air And Ice Cores, Murat Aydin, S. A. Montzka, M. O. Battle, M. B. Williams, Warren J. De Bruyn, J. H. Butler, K. R. Verhulst, C. Tatum, B. K. Gun, D. A. Plotkin, B. D. Hall, Eric S. Saltzman
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
In this study, we report measurements of CFC-12 (CCl2F2) in firn air and in air extracted from shallow ice cores from three Antarctic sites. The firn air data are consistent with the known atmospheric history of CFC-12. In contrast, some of the ice core samples collected near the firn-ice transition exhibit anomalously high CFC-12 levels. Together, the ice core and firn air data provide evidence for the presence of modern air entrapped in the shallow ice core samples that likely contained open pores at the time of collection. We propose that this is due to closure of the open pores ...
Higher-Order Physic For Modeling Ice Streams In Ice Sheets, 2010 The University of Maine
Higher-Order Physic For Modeling Ice Streams In Ice Sheets, Debra A. Kenneway
Electronic Theses and Dissertations
Ice streams are transitional between inland glaciers and ice shelves. Hence no stresses can be neglected. Ice streams are important dynamic features of a glacier; it is well known that ice streams drain up to 90% of the ice from an ice sheet. Herein I model ice streams as a multiphysics system of coupled components. This includes treating ice as a non-Newtonian fluid since empirical measurements show a power law relation between stress and strain rate. Sliding is a physical feature that must be included. This is done with a novel approach to sliding by way of a slippery layer ...
Climate Investigations Using Ice Sheet And Mass Balance Models With Emphasis On North American Glaciation, 2010 The University of Maine
Climate Investigations Using Ice Sheet And Mass Balance Models With Emphasis On North American Glaciation, Sean David Birkel
Electronic Theses and Dissertations
This dissertation describes the application of the University of Maine Ice Sheet Model (UM-ISM) and Environmental Change Model (UM-ECM) to understanding mechanisms of ice-sheet/climate integration during ice ages. The UM-ECM, written by the author for this research, calculates equilibrium biome and snow/ice mass balance solutions for the globe based on modern input climatology and user-defined parameter values. The program was produced in conjunction with a National Science Foundation ITEST grant meant to seed inquiry-based classroom study of Earth systems using computer models. To that end, the UM-ECM serves as both a research and teaching tool. The model has ...