Toronto's future weather and climate driver study /

Why We Get What We Get The main focus of the work undertaken for the City is an understanding of what the City of Toronto currently experiences and, more importantly, why the City experiences what it does, and why and what the City of Toronto will experience in the future. [...] By drivers we are referring to the big picture things – the meandering path of the jet stream, the development and movement of air masses, the position of high and low pressure cells and the associated wind, cloud, heat and moisture characteristics that result in Toronto's weather. [...] They are able to simulate the main features of the current climate and its variability such as the seasonal cycles of temperature and rainfall in different regions of the Earth, the formation and decay of hurricanes, the seasonal shift of the major rain belts and storm tracks, the average daily temperature cycle, the variations in outgoing radiation at high elevations in the atmosphere as measured [...] Over the long run, the processes of absorption and emission of radiation at the ground and in various layers of the atmosphere have produced a balance between the incoming and outgoing energy, keeping our world a warm enough place to live and providing the driving forces for atmospheric motion. [...] The location of the invisible line that separates tropical from polar air (of such great importance to Toronto) is itself a dynamic moving wave line, or vertical curtain, extending through the lowest layer of the atmosphere (the troposphere) from the ground to the air aloft at its upper limit the tropopause (or the boundary between the troposphere and the stratosphere above it).