1. U RBAN H EAT I SLAND : W HY IT IS HOTTER IN THE CITY THAN IN THE COUNTRYSIDE ? Los Angeles Model By Fernando Olmos 3/15/13

2. L ESSON O UTLINE Day 1 Presentation of the Urban Heat Island Effect Hands-on activities at the stations Day 2 Worksheet Reflection on Solutions to the Urban Heat Island Effect

3. G OAL Understand how the following phenomena contribute to the Urban Heat Island Effect: Sun light Black body properties of materials 3 heat transfer mechanisms (conduction, convection, radiation) Come up with solutions to mitigate the Urban Heat Island Effect

4. R EVIEW OF H EAT T RANSFER M ECHANISMS Conduction: heat is transferred by direct contact between objects Convection: heat is transferred in a fluid (liquid or gas) Radiation: heat is transferred in the form of electromagnetic waves Remember: Heat is always transferred from HOT to COLD!!!

5. U RBAN H EAT I SLAND (UHI) A urban heat island is a metropolitan area that is at a warmer temperature than the surrounding countryside Around 2 to 10 o F (2-6 o C) Not only air is hotter, but different surfaces are hotter.

6. C AUSES OF UHI Presence of dark and dry surfaces High heat (sunlight) absorption Examples: pavement, asphalt, buildings Absence of vegetation Shade blocks solar radiation Plants sweat water, and heat is removed (40 gallons a day)

7. C ONSEQUENCES UHI More air conditioning (1-1.5 gigawatts) More electricity, more emission of GHG More smog More health problems Eye irritation, lung damage, asthma Vegetation issues

8. L OS A NGELES UHI I Increase of annual urban temperatures over the last decade in several UHIs

9. L OS A NGELES UHI II Increase in LA temperatures as a result of urbanization and industrialization

10. L OS A NGELES UHI III Increase in electricity use in LA. 2% increase for every 1 o F increase in temperature

11. L OS A NGELES UHI IV Higher temperatures means more ozone or smog will be produce