Environmental Sciences Course Air Pollution and Climate Change Dr.-Eng. Hasan Hamouda Eng. Osama Othman

Outline Atmosphere and Climate Climate Change Climate and Pollution - El Nino - Human Causes Climate and Pollution - Kinds of Pollution - Sources - Transport Effects of Air Pollution Air Pollution Control University Of Palestine UNI 3316 Dr. Hasan Hamouda - Eng. Osama Othman

ATMOSPHERE AND CLIMATE Weather - A description of short-term physical conditions of the atmosphere. Climate - A description of the long-term weather pattern in a particular area. Weather and climate are primary determinants of biomes and ecosystem distribution. University Of Palestine UNI 3316 Dr. Hasan Hamouda - Eng. Osama Othman

Troposphere Troposphere - Ranges in depth from 18 km over the equator to 5 km over the poles. - Air circulates in convection currents. - Air temperature drops rapidly with increasing altitude - Contains 75% of total air mass. Tropopause: Transition boundary limits mixing between the troposphere and upper zones. University Of Palestine UNI 3316 Dr. Hasan Hamouda - Eng. Osama Othman

A Layered Envelope Stratosphere - Extends from troposphere to about 50 km. - Similar composition to Troposphere, but much more dilute. - Temperature increases with altitude. - Fraction of water vapor is 1000x less and ozone is 1000x more than in the troposphere. - Relatively calm University Of Palestine UNI 3316 Dr. Hasan Hamouda - Eng. Osama Othman

A Layered Envelope Mesosphere -Middle Layer. -Minimum temperature is about - 80o C. Thermosphere - Ionized gases and high temperatures. - Ionosphere - Lower Thermosphere - Aurora borealis (northern lights) University Of Palestine UNI 3316 Dr. Hasan Hamouda - Eng. Osama Othman

Atmospheric Temperature Changes University Of Palestine UNI 3316 Dr. Hasan Hamouda - Eng. Osama Othman

Energy & Greenhouse Effect Solar Radiation - Solar energy not evenly distributed over the globe. - Of solar energy reaching outer atmosphere: 25% reflected 25% absorbed 50% reaches earth’s surface University Of Palestine UNI 3316 Dr. Hasan Hamouda - Eng. Osama Othman

Solar Radiation Visible light: passes through atmosphere undiminished. Ultraviolet light: is absorbed by ozone in the stratosphere. Infrared radiation: is absorbed by carbon dioxide and water in the troposphere. - Albedo - Reflectivity - Fresh clean snow 90% - Dark soil 3% - Net average of earth 30% University Of Palestine UNI 3316 Dr. Hasan Hamouda - Eng. Osama Othman

Solar Radiation University Of Palestine UNI 3316 Dr. Hasan Hamouda - Eng. Osama Othman

Solar Radiation Most solar energy reaching the earth is visible light. - Energy remitted by the earth is mainly infrared radiation ( heat energy). - Longer wavelengths are absorbed in the - lower atmosphere, trapping heat close to the earth’s surface. Greenhouse Effect: Increasing atmospheric CO2 due to human activities appears to be causing global warming. University Of Palestine UNI 3316 Dr. Hasan Hamouda - Eng. Osama Othman

Convection & Atmospheric Pressure - Water vapor contains a large amount of energy stored as latent heat. - Evaporation converts solar energy into latent heat stored in evaporated water. - Uneven heating produces pressure differences that cause wind, rain, and storms (weather). - Vertical convection cells circulate air masses between warm and cooler latitudes. University Of Palestine UNI 3316 Dr. Hasan Hamouda - Eng. Osama Othman

Why Does It Rain ? Releasing latent heat causes air to rise, cool, and lose more water vapor. - Rising, expanding air creates an area of relatively high pressure at the top of the convection column. - Air flows out of high-pressure zone towards areas of low-pressure, where cool, dry air is subsiding. University Of Palestine UNI 3316 Dr. Hasan Hamouda - Eng. Osama Othman

Why Does It Rain ? - Subsiding air is compressed as it approaches the earth’s surface where it piles up and creates an area of high pressure at the surface. - Air flows out of this region back towards low pressure, closing the cycle. If condensation nuclei are present, or if temperatures are low enough, condensation will lead to precipitation. University Of Palestine UNI 3316 Dr. Hasan Hamouda - Eng. Osama Othman

Convection Currents University Of Palestine UNI 3316 Dr. Hasan Hamouda - Eng. Osama Othman

Coriolis Effect & Jet Streams - Surface flows do not move straight North and South, but are deflected due to Coriolis Effect. - Major zones of subsidence occur at about 30o north and south latitude. - Where dry, subsiding air falls on continents, it creates broad, subtropical desert regions. - Winds directly under regions of subsiding air are often light and variable - Horse latitudes University Of Palestine UNI 3316 Dr. Hasan Hamouda - Eng. Osama Othman

Convection Cells & Prevailing Winds University Of Palestine UNI 3316 Dr. Hasan Hamouda - Eng. Osama Othman

Jet Streams University Of Palestine UNI 3316 Dr. Hasan Hamouda - Eng. Osama Othman

Seasonal Winds Monsoon - Seasonal reversal of wind patterns caused by differential heating and cooling rates of oceans and continents. - Most prevalent in tropical countries where large land area is cut off from continental air masses by mountain ranges and surrounded by a large volume of water. University Of Palestine UNI 3316 Dr. Hasan Hamouda - Eng. Osama Othman

Monsoon University Of Palestine UNI 3316 Dr. Hasan Hamouda - Eng. Osama Othman