Atmosphere, Ocean and Environmental Change Ronald B. Smith

The seasonal cycle on Earth causes shifts in the bands of precipitation in the northern and southern hemispheres. The polar front shifts between high and mid-latitudes which causes a latitudinal shift in the occurrence of frontal cyclones. The Intertropical Convergence Zone also shifts across the equator bringing bands of precipitation to different tropical regions throughout the year. Regional climates on Earth have been classified based on temperature and precipitation values. Areas affected by seasonal shifts in the ITCZ and polar front are included in this classification scheme. Several examples of seasonality are discussed as well as seasonal weather and climate events.

Complete course materials are available at the Open Yale Courses website: http://oyc.yale.edu

This course was recorded in Fall 2011.

Renewable energy sources are discussed. These include wind energy, solar energy, biomass energy and geothermal energy. Energy from wind is acquired through the use of large wind turbines. These turbines ideally need to be located in areas where there is strong wind and low atmospheric turbulence. Solar power is collected using both photovoltaic solar cells and concentrated solar power. Energy from biomass can be produced in two ways: burning biomass to generate electricity or fermentation to produce fuel ethanol. Geothermal energy is produced by pumping water below the earth’s surface into areas of hot rocks which heats the water and creates steam. This steam is then run through a turbine to produce power.

Complete course materials are available at the Open Yale Courses website: http://oyc.yale.edu

This course was recorded in Fall 2011.

The various types of resources currently used for energy production are discussed. Energy is primarily used for heating, transportation, and generating electricity. Coal is burned largely to produce electricity and is a major contributor to air pollution with coal power plants emitting carbon dioxides and nitrous oxides. Another major resource used for energy is oil. It is projected that each country either has reached or will reach a peak oil use, after which oil use will decrease. Natural gas is now being obtained from shale using the extraction technique of fracting which is a recent discovery. Nuclear power gained popularity worldwide through the 1970s, however very few new power plants have been built in the last three decades following the Three Mile Island and Chernobyl episodes. Hydroelectric power is generated by forcing water flowing from high terrain through a turbine to produce electricity. There are many hydroelectric dams operating globally.

Complete course materials are available at the Open Yale Courses website: http://oyc.yale.edu

This course was recorded in Fall 2011.

The material covered throughout the course is reviewed. Properties of air and water are discussed. Hydrostatic balance is discussed as related to the atmosphere, ocean and solid earth. Geostrophic balance is a force balance between the Coriolis force and the pressure gradient force, and applies to winds in the atmosphere as well as currents in the ocean. Several examples of equilibrium states are reviewed. Heat and mass are transported by fluid motion in the earth system through winds, ocean currents and rivers. Mixing, dilution and concentration is discussed as related to ocean and atmosphere pollutants as well as salinity in the ocean. Finally, symmetry between the northern and southern hemispheres is discussed, focusing on differences in land mass, Coriolis force and the seasons.

Complete course materials are available at the Open Yale Courses website: http://oyc.yale.edu

This course was recorded in Fall 2011.

Stratospheric ozone is important as protection from harmful ultraviolet solar radiation. Ozone in the stratosphere blocks almost all UVC radiation, which is extremely energetic and harmful. Ozone within the ozone layer is destroyed through chemical reactions involving chlorine atoms and the ozone molecules. The main anthropogenic source of chlorine in the atmosphere is chlorofluorocarbons (CFCs). Emissions of CFCs began to increase after 1960 and continued to increase until the 1990s. The 1987 Montreal Protocol banned the emission of CFCs as of 1994, and currently CFC emissions are nearly zero.

Complete course materials are available at the Open Yale Courses website: http://oyc.yale.edu

This course was recorded in Fall 2011.

Climate sensitivity is defined as either the temperature change resulting from a doubling of atmospheric carbon dioxide concentration or the temperature change resulting from a 1W/m2 increase in radiative forcing. There are several different climate sensitivities that take into account different feedbacks in the climate system. The simplest climate sensitivity is black body sensitivity, which does not account for any feedbacks but gives the temperature change resulting just from a change in radiative forcing. The calculated climate sensitivity based only on the Stefan-Boltzmann Law is lower than the climate sensitivity calculated using both temperature data over the last 100 years and ice age data over the last ~200,000 years, indicating that feedbacks have played a role in climate sensitivity. World population is also discussed, with population trends outlined for various countries as well as trends associated with developing areas versus developed areas. The issue of sustainable population is introduced.

Complete course materials are available at the Open Yale Courses website: http://oyc.yale.edu

This course was recorded in Fall 2011.