Thermal Energy & Temperature Temperature measures the average kinetic energy of all the particles in a substance Temperature is the average amount of energy of motion of those particles The greater the movement/kinetic energy, the hotter the temperature

Conduction - Energy transfer within a solid by direct contact.

Conduction: From Latin conducere, to bring together Conductors allow for electrons to be transported from particle to particle. If a charged conductor is touched to another object, the conductor can even transfer its charge to that object.

Convection - Energy transfer within fluids from one place to another.

Convection -convectio, from Latin convehere to bring together

Convection Heating Hot Air Rises Cold Air Sinks

Convection Redistributes heat – These air currents also carry moisture QUESTION: How do air currents differ from this simple picture? Why? QUESTION2: What part of this simple picture still holds true

Radiation - Energy transfer by waves.

Radiation - from Latin radiationem "a shining, radiation,” - stem of radiare "to beam, shine, gleam - from radius “rays or beams emitted” Radiators

What two types of heat transfer do home radiators use?

Radiation - from Latin radiationem "a shining, radiation,” - stem of radiare "to beam, shine, gleam - from radius “rays or beams emitted” Radiant Flooring

Radiant Driveways and Sidewalks

Ultimately, climate and weather determined by energy exchange between Earth and Space And that can only by by what process?

Weather is caused by changes in TEMPERATURE -The farther from the Earth’s surface the cooler the air. - Some radiant energy (heat) from the sun is reflected off the Earth and “trapped” by the ozone layer and clouds, keeping the surface and lower levels of the troposphere warm. -WHAT’s THIS PROCESS CALLED?

How do greenhouses work?

Global Mean Surface Temperatures Have Increased ???

From M. Prather University of California at Irvine ???

The Land and Oceans Have Warmed

Shrinking Arctic Sea Ice NASA-Data

Shrinking Arctic Sea Ice NASA-Data

Source: World Resources Time Magazine – 9 April 2001

Scientific Consensus “An increasing body of observations gives a collective picture of a warming world and other changes in the climate system” Global average surface temperature has increased over the 20th century by about 0.6°C The last decade of the 20 th century was the warmest decade of the past millennium Temperatures have risen during the past four decades in the lowest 8 kilometers of the atmosphere Snow cover and ice extent have decreased. Global average sea level has risen and ocean heat content has increased

There is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities Drastic changes in the world ’ s population and ecosystems Human influences will continue to change atmospheric composition throughout the 21st century Global average temperature and sea level are projected to rise More

Identify the spheres

What Should We Believe? The atmosphere and oceans are warming consistent with model simulations The glaciers are melting. The temperature, rain, and snow observational trends are consistent with model simulations The global changes are much larger than can be explained from natural variability of climate