Urban Heat IslandUrban Heat Island

The Role of Thermal InertiaThe Role of Thermal Inertia

http://pdphoto.org/PictureDetail.php?pg=7954&mat=pdefhttp://pdphoto.org/PictureDetail.php?pg=7954&mat=pdef

What Is “Urban Heat Island”?

http://eetd.lbl.gov/HeatIsland/HighTemps/

Important Factors

Albedo• Tells us lighter objects reflect more incoming radiation than darker objects

Moisture and Vegetation• Parks and agricultural fields reduce urban heat island through evaporative cooling

(from Christopherson, 2004)

Some More Terms:Some More Terms:1) Thermal Inertia – The

potential of a material to absorb and store heat

2) Oasis Effect – Where cities can be cooler during the day than the surrounding countryside

3) Remote Sensing – Involves the acquisition of earth surface characteristics using a remote device

Thermal Inertia

Oasis Effect

Heat Island

Rural Urban

What Do You Think Will Be What Do You Think Will Be Hotter, the Sand or the Hotter, the Sand or the

Concrete?Concrete?

Infrared Thermometer (Our Remote Sensor)

An Example Beyond Urban Heat Island: An Example Beyond Urban Heat Island: Using Thermal Inertia to Better Understand MarsUsing Thermal Inertia to Better Understand Mars

(Images Courtesy of NASA)(Images Courtesy of NASA)

Warm

“Day” “Night”

CoolWarm

Cool

Warm

“Day” “Night”

Cool

Warm

Cool

Charlie’s Angels and Thermal InertiaCharlie’s Angels and Thermal Inertia

NighttimeNighttimePhoenixPhoenix

(http://elwood.la.asu.edu/grsl/UEM/)

A_____

B_____

C_____

D_____

Analysis:Use your knowledge of greater Phoenix and urban heat island to decipher what each of these letters are referring to.

10:39pm 10/3/03

How Does Phoenix Compare?

(image courtesy of NASA)

What kinds of problems might stem from urban heat island, if any?

Things to know:Things to know:

• What is Urban Heat Island?What is Urban Heat Island?

• How does albedo, moisture, and vegetation How does albedo, moisture, and vegetation play a role in urban heat island?play a role in urban heat island?

• Understand and describe Thermal Inertia, Understand and describe Thermal Inertia, Oasis Effect, and Remote Sensing and how Oasis Effect, and Remote Sensing and how they relate to urban heat island.they relate to urban heat island.

Help: Chapter ATHelp: Chapter AT