Presentation on theme: "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."— Presentation transcript:
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 = 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.
I n s o l a t i o n Incoming solar radiation 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.
Electromagnetic Spectrum Solar Radiation Terrestrial Radiation
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
And once there, it can be: Absorbed Reflected Scattered Transmitted Albedo: the reflectivity of an object
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
Earths Energy Budget: a long-term balance Heating of the Atmosphere video
Variations in temperature/heating are controlled by… Latitudinal Differences angle of incidence Where is the angle of incidence the largest and the smallest?
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
Spatial variations in heating: …is further controlled by how much atmosphere the solar radiation has to travel through as well as atmospheric obstruction. gases particulates clouds Where is the longest path found that solar radiation must take? Energy Budget & Latitude: Diagram
Characteristics of Land and Water: differences in heating Heating - land surfaces heat up more rapidly than water. Cooling – land surfaces cool off more rapidly than water. Implications - Continental land surfaces (inland) have a higher range in daily temperatures, Maritime coastal surfaces (along the ocean) have a lower range in daily temperatures.
Land and Water contrasts: Annual Temperature Curves Continental vs maritime climates
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 This imbalance is addressed by…
Global Temperature Patterns Changes with latitude and season
Summary of Global Temperature Controls Altitude/Elevation Latitude (0-90 N/S) Seasons Land-Water Contrasts Oceanic Currents
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.
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
Vertical Temperature Patterns Radiational surface inversion Example: Los Angeles major vs. minor smog days
INTERNATIONAL DEBATE 1992 Rio de Janeiro – established panel of scientists to study climate change… Intergovernmental Panel on Climate Change (IPCC). 1997 Kyoto Protocol – 167 countries agreed to reduce carbon emissions to 1990 levels (Europe 8%, Japan 6%, USA 7%). (President Clinton) 1998 Buenos Aires – USA 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 Marakesh – USA did not attend climate meeting. (President Bush) 2005 Russia ratified the Kyoto agreement, USAs federal government did not; ignoring global warming and the greenhouse effect. 2009 Copenhagen Climate Meeting, Denmark – USA and China worked together; possible 2010 treaty to reduce anthropogenic greenhouse gases at home and abroad. Clean energy, accountability/transparency, key to controlling global warming. (President Obama)
The problem: Rate of change –Intergovernmental Panel on Climate Change (IPCC) –Warming at unprecedented rates –Increase in temperature vs. time –Cause is predominantly anthropogenic = HUMANS 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 –Species/Community extinctions Can we survive it? –Can we change? ADAPT
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 1.Read Chapter 4 2.ARTICLE (handout in class). 3.Write a summary about your opinion on global warming and use your own observations and available research to back up your statements. 5 HWs total due before the midterm.