Simulation of glacial inceptions with the "green" McGill paleoclimate model

• Main Author: Cochelin, Anne-Sophie
• Format: Thesis
• Language: English
• Published: McGill University 2004
• Subjects: Physics; Atmospheric Science; Ice Sheet
• Online Access: http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=81274

The McGill Paleoclimate Model (MPM) was used to simulate the past and future glacial inceptions. This model of intermediate complexity was first run between 122 and 80 kyr BP (Before Present). After some parameter tuning, the MPM simulated the last glacial inception at 119 kyr BP. The recent addition of a vegetation component in the model led to an improvement of the results, especially for the ice sheet distribution over Eurasia. The MPM was then run to simulate projections of the climate for the next 100 kyr and possibly the next glacial inception. When forced by a constant atmospheric CO2 concentration, the model predicted three possible evolutions for the ice volume: an imminent glacial inception (low CO2 levels), a glacial inception in 50 kyr (intermediate CO2 levels) or no glacial inception during the next 100 kyr (CO2 levels of 370 ppm and higher). This is mainly due to the exceptional configuration of the future variations of the summer insolation at high northern latitudes. The MPM also responded realistically to rapid CO2 changes. If a global warming episode was included at the beginning of the 100-kyr run, the evolution of the climate was slightly different and the threshold over which no glacial inception occurred was lower (300 ppm).