Published on April 7, 2008
Slide2: Energy = the ability to do work; anything that changes the state or condition of matter. The sun, a large thermonuclear reactor, supplies the energy that supports life on earth and energizes most atmospheric processes. This energy is derived through the process of fusion. Temperature: Temperature = a description of the average kinetic energy, or energy of movement, of the molecules in a substance Temperature scales: Fahrenheit, Celsius, Kelvin Heat (thermal energy) is transferred from one object to another because of differences in temperature. Slide4: I n s o l a t i o n Energy from the sun is radiated out in the form of electromagnetic waves which travel at the speed of light. EM waves are classified according to their wavelength. Slide5: Electromagnetic Spectrum Solar Radiation Terrestrial Radiation Slide6: This energy can move from place to place by: Radiation – flow of energy emitted from an object Conduction – movement of energy from molecule to molecule Convection – energy transferred vertically by a moving substance Advection – energy transferred horizontally by a moving substance Slide7: And once there, it can be: Absorbed Reflected Scattered Transmitted Albedo: the reflectivity of an object Heating and Cooling Processes: Heating and Cooling Processes Adiabatic cooling rising air expansion Adiabatic warming descending air compression No loss or gain of heat with either Latent heat: the storage or release of energy through phase changes in the physical state of matter Loss or gain of heat Earth’s Energy Budget: a long-term balance: Earth’s Energy Budget: a long-term balance Heating of the Atmosphere video Variations in temperature/heating are controlled by…Latitudinal Differences: Variations in temperature/heating are controlled by… Latitudinal Differences angle of incidence Where is the angle of incidence the largest and the smallest? Slide11: Variations in temperature/heating are controlled by… Different locations have different: day lengths Where on Earth does daylight and darkness occur in equal lengths of time always (12 hours each)? Where on Earth does daylight and darkness occur in unequal lengths of time (24 hours only)? Seasonal Differences Slide12: Spatial variations in heating: It is further controlled by how much atmosphere the solar radiation has travel through as well as atmospheric obstruction. particulates gases clouds Where is the longest path found that solar radiation must take? Characteristics of Land and Water: differences in heating : Characteristics of Land and Water: differences in heating Slide14: Heating - land surfaces heat up more rapidly than water. Cooling – land surfaces cool off more rapidly than water. Implications - land surfaces that are not near the coast have a higher range in daily temperatures … Land and Water contrasts:Annual Temperature Curves: Land and Water contrasts: Annual Temperature Curves Continental vs maritime climates Slide16: Spatial variations in heating Latitudinal Radiation Balance - the surplus radiation that results in the tropics is balanced by the deficit that occurs in the polar regions. Heat Transfer Mechanisms: Atmospheric and Oceanic Circulation: Heat Transfer Mechanisms: Atmospheric and Oceanic Circulation This imbalance is addressed by… Slide18: Global Temperature Patterns Changes with latitude and season Global Average AnnualTemperature Variations: Global Average Annual Temperature Variations Summary ofGlobal Temperature Controls: Summary of Global Temperature Controls Altitude Latitude Land-Water Contrasts Oceanic Currents Ozone Loss over the Poles: Ozone Loss over the Poles CFCs originate in Northern Hemisphere redirected by winds (toward poles) stratosphere high, thin cloud cover cold temperatures Chlorine atoms freed at high rates (poles) “hole” over Antarctica larger than Arctic Mid-lats also experiencing ozone thinning UV passes to Earth’s surface Slide22: Sensible temperature - what we feel the air temperature to be, taking into account all factors like amount of moisture present, the wind (if present), etc. Slide23: Vertical Temperature Patterns Environmental lapse rates – the observed trends of vertical temperature changes in the atmosphere Temperature Inversions: Surface Radiational inversions – most common type of inversion layer seen at ground level, caused by rapid cooling at the surface during the night time with warmer air aloft Advectional inversions – during a horizontal inflow of cold air into an area, commonly produced by cool maritime air moving inland that displaces warm air masses Cold-air drainage inversions – during winter in some mid-latitude regions, cold air slides down a slope into a valley displacing warmer air Upper-Air Subsidence inversions – a deep/aloft inversion, the result of sinking air associated with high-pressure conditions Slide24: Vertical Temperature Patterns Radiational surface inversion Example: Los Angeles major vs. minor smog days Global Warming andthe Greenhouse Effect: Global Warming and the Greenhouse Effect Slide26: http://www.msnbc.com/news/106332.asp?cp1=1 Global Warming video Slide27: Human-induced atmospheric changes CO2 Human-Enhanced Global Warming: Human-Enhanced Global Warming Kyoto??? INTERNATIONAL DEBATE: INTERNATIONAL DEBATE 1992 Rio de Janeiro established panel of scientists to study climate change 1997 Kyoto – 167 countries agreed to reduce carbon emissions to 1990 levels (Europe 8%, Japan 6%, USA 7%) 1998 Buenos Aires – US threatened not to make cuts unless developing countries (ex. India and China) also make cuts 2000 The Hague – stand off between Europe and USA re: methods. USA wants to meet ½ target by using carbon sinks and trading 2001 US did not attend meeting in Marakesh Recently Russia ratified the Kyoto agreement, while the USA’s federal government has not; ignoring human-enhanced global warming and the greenhouse effect at home and abroad The problem:: The problem: Rate of change Intergovernmental Panel on Climate Change (IPCC) Warming at unprecedented rates Increase in temperature vs. time Cause is predominantly anthropogenic Increased global average temperatures 1 degree F every century? Predicting even more change (up to 7 degrees this century)! Expected changes for Earth Melting of polar ice Increase in sea level Shifts in climate everywhere Extreme weather phenomena More extinctions Can we survive it? Can we change? Hurricane Dean became a low pressure system affecting the south-western USA in August 2007…is our local semi-arid climate becoming more tropical?: Hurricane Dean became a low pressure system affecting the south-western USA in August 2007…is our local semi-arid climate becoming more tropical? Homework: Homework Read Ch. 4 and article (in class handout). Write a summary about your opinion on global warming and use your own observations and available research to back up your statements. Due next week (or) before the midterm.