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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…
 
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 sol…
 
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…
 
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 …
 
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…
 
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…
 
There are two ozone problems in the atmosphere. Tropospheric ozone in the form of photochemical smog is sometimes dangerously high whereas stratospheric ozone concentration is sometimes dangerously low. Photochemical smog is created through chemical reactions between UV radiation from the run and nitrogen oxides that are emitted from automobiles. H…
 
Several greenhouse gas emissions scenarios have been developed by the IPCC to determine possible affects on atmospheric greenhouse gas concentrations and related climate warming. The largest estimates show a carbon dioxide concentration of about 800ppmv by the year 2100. Lower estimates rise to 450ppmv by the year 2100. The amount of projected warm…
 
The current Holocene epoch is considered to be a time period of relatively stable climate compared to earlier geological periods. Still, some significant changes in temperature and sea level did occur. These climatic fluctuations include the Medieval Warm Period and the Little Ice Age, and more recently global warming. Temperature data for the 20th…
 
Isotopes are used to measure past climate properties. Deuterium and oxygen 18 are the most commonly used climate proxies. Lighter isotopes evaporate more readily from the ocean, so water vapor in the atmosphere is isotopically lighter than ocean water. This vapor gets lighter still as it is transported to higher latitudes while losing mass by preci…
 
The issue of global warming is discussed. Recent climate change over the last half of the 20th century is thought to be driven largely by greenhouse gas emissions, with carbon dioxide playing a large role. The carbon cycle describes the reservoirs of carbon (atmosphere, terrestrial biomass and ocean) and the exchanges that occur between these reser…
 
Ice on earth is sensitive to climate change and ice plays a role in climate change processes. Recent trends in the Greenland ice sheet provide an important example. Over the past two decades the extent of surface melt water on the ice sheet has increased. Inaddition, satellites have detected a decrease in the overall mass of the Greenland Ice Sheet…
 
The El Niño/Southern Oscillation (ENSO) phenomenon is the primary mode of variability in the equatorial Pacific Ocean. It is composed of two extreme states, El Niño and La Niña. The oscillation between these states can be seen in measurements of sea surface temperature (SST), sea level pressure, thermocline depth, and easterly trade wind strength. …
 
Five types of ice in the climate system are discussed. Sea ice forms when ocean water reaches its freezing temperature of about -2°C. Sea ice is currently found in the Arctic Ocean and around Antarctica. Ice sheets form on land and are composed of compacted snow that has accumulated over time. Ice sheets spread over a land surface and can reach the…
 
The atmosphere forces the ocean in three ways: addition and removal of heat, precipitation and evaporation, and wind stress. The former two processes influence the density of sea water. Gravity acts on these density differences to cause large-scale thermohaline currents Wind driven ocean currents are forced by the wind stress acting on the ocean su…
 
Ocean currents are generally divided into two categories: thermohaline currents and wind driven currents. Both types of currents are forced remotely rather than locally. Wind driven currents are initially forced by the wind stress causing water to pile up in certain locations. This produces a pressure gradient, which is then balanced by the Corioli…
 
There are several factors that impact climate on Earth. Different areas on Earth have different climates depending on factors such as their latitude and surrounding terrain. Maps of annual average precipitation illustrate these variations in climate. Continentality also affects climate based on the ability to change temperatures on land versus in t…
 
Stability in the ocean is based on the density of the water. Density must increase with depth in order for the ocean to be stable. Density is a function of both temperature and salinity, with cold salty water having a higher density than warm fresh water. Temperature and salinity in the ocean can be affected by the atmosphere. Heat can be added to …
 
Plate tectonics and ocean bathymetry are discussed. Bathymetry is the study of ocean depth, which is affected in some regions by plate tectonics and mantle dynamics. Mid-ocean ridges are formed at plate boundaries where mantle material is rising to the ocean crust and solidifying as it cools to form new ocean crust material. Seamounts are volcanoes…
 
Mid-latitude frontal cyclones gain energy from temperature gradients rather than latent heat release as is the case with convective storms. They form in the belt of westerly winds and therefore generally move west to east in both the northern and southern hemispheres. A mid-latitude frontal cyclone develops from a kink in the polar front, and event…
 
Large scale air motion in the atmosphere occurring sufficiently above the surface is in geostrophic balance. Areas of high and low pressure anomalies in the atmosphere are surrounded by rotating flow caused by the balance between the pressure gradient and Coriolis forces. The direction of rotation around these pressure anomalies reverses between th…
 
There are three main types of convective storms: airmass thunderstorms, severe thunderstorms and hurricanes. These storms are all driven by the release of latent heat into the atmosphere during condensation of water vapor. Severe thunderstorms include both squall line thunderstorms and tornados. They acquire energy from water vapor in the atmospher…
 
The circulation in the atmosphere is composed of three circulation cells in the northern and southern hemispheres. These cells are caused by the rotation of the Earth which creates the Coriolis force. The Coriolis force deflects northern hemisphere motion to the right and southern hemisphere motion to the left. The majority of large-scale motion in…
 
There is a latitudinal gradient of heat on the Earth caused by the tilt of the Earth’s axis with respect to the sun. This tilt produces seasonal fluctuations in heat input from the sun, as well as an excess of heat received on average annually near the equator. Heat is transferred poleward by both the ocean and atmosphere in an attempt to balance t…
 
Scattered visible light and microwave radar can used used to detect clouds and precipitation. Cloud formation in rising air can be simulated in the classroom by suddenly dropping the pressure in a glass chamber. The small cloud droplets formed in this way fall too slowly to ever reach the earth. There are two main mechanisms by which precipitation …
 
Air is able to hold a limited amount of water vapor, and that amount depends on the temperature of the air. When this saturation vapor pressure is exceeded, liquid water begins to condense and clouds form. There are several different types of clouds, some which rain and others which do not, and each with characteristics specific to it. Vortices are…
 
The lapse rate describes the rate at which air cools with altitude. Atmospheric stability depends on the lapse rate. When an air parcel is lifted or lowered, it can continue to rise or descend based on the temperature of the surrounding air at the new altitude, which indicates an unstable atmosphere. Inversions can occur in the atmosphere, meaning …
 
This lecture describes how pollutants mix in the atmosphere. Three cases are considered: confined mixing, unconfined mixing, and unconfined mixing with wind. In a confined volume, the concentration of pollutant in the air depends on the volume and the mass of the air present in the volume. Unconfined mixing is also known as diffusion, in which the …
 
The hydrostatic law describes the weight of a fluid overlying a given area, or the pressure at a particular point. It can be used to calculate the approximate atmospheric mass over a particular area, or to calculate the change in pressure over a given change in altitude. A calculation of the pressure difference from the ground to the twelfth floor …
 
A simple model of the overall Earth’s heat budget is derived. The Earth is assumed to be in equilibrium with the input of solar radiation balanced by the output of infrared radiation emitted by the Earth’s surface. Using this model, the Earth’s surface temperature is calculated to be cooler than in reality due to the lack of an atmosphere and the g…
 
This course studies the atmosphere and the ocean as parts of Earth’s climate system. The climate is studied in both quantitative and qualitative ways through use of the textbook, lectures, labs and problem sets. Today’s lecture includes an examination of Hurricane Irene that hit Connecticut a few days ago on August 28. For this, we use several webs…
 
Pressure and density decrease exponentially with altitude in the atmosphere. This leads to buoyancy effects in the atmosphere when parcels of air are heated or cooled, or raised or lowered in the atmosphere. Temperature varies in a more complicated way with altitude in the atmosphere, with several inversions which occur at the boundaries of the var…
 
The Perfect Gas Law relates temperature, pressure, and density of gases in the atmosphere. It can be used to demonstrate why warm air rises, cool air sinks, and helium balloons float in the air. Buoyancy forces act in fluids (both water and air) when fluid is displaced by a parcel of a fluid with a different density. A combination of buoyancy force…
 
Several experiments are performed using a water tank with an input flow of water and an output flow. These experiments demonstrate the concepts of equilibrium and steady-state in system analysis and are analogous to various Earth systems; lakes and rivers and the overall heat budget of the planet. The greenhouse effect in the atmosphere is a mechan…
 
There are other ways in which we can perceive the existence of the atmosphere, predominantly through our perceptions of pressure. Not all planets have atmospheres, and the existence of an atmosphere depends on the ability of gas molecules to remain trapped close to a planet by its gravitational force. The molecular velocity of each gas molecule dep…
 
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