Geography 2153A/B Lecture Notes - Lecture 3: Feedback, Positive Feedback, Negative Feedback

• School: Western University
• Department: Geography
• Course: Geography 2153A/B
• Professor: Susan Dupej

Document Summary

What is a system: a network of relationships among parts, elements or components that interact with and influence one another (exchange energy, matter or information, ex. Computer networks, human body, production system, flight traffic. Systems theory: all systems require a source of energy to drive them (ex. Open and closed system: can exchange matter but not energy, earth is an open system because it receives inputs from the sun. In nature all systems are open because there is an exchange in energy and matter. Earth as a system: earth is a system composed of numerous interacting subsystems, air, water, land, life, earth"s spheres (cid:894)at(cid:373)osphere, geosphere, (cid:271)iosphere, h(cid:455)drosphere, a(cid:374)throsphere(cid:895, between these spheres, energy is being moved and transferred. The atmosphere: envelope of gases that surround the earth, 5 main layers, composition of atmosphere: nitrogen = 78%, oxygen = 21%, water = varies, argon = 0. 9%, carbon dioxide = 0. 03: at(cid:373)osphere prote(cid:272)ts the earth"s i(cid:374)ha(cid:271)ita(cid:374)ts fro(cid:373) har(cid:373)ful uv rays.