Understanding Systems, Productivity, Global Warming, and Photochemical Smog

SYSTEMS

Can be small or large, living or non-living.

Types: open, close and isolated

• Open: exchanges both energy and matter
• Close: only exchange energy
• Isolated: Energy and matter is not exchange

Transfer: Basic flow through a system. Change in location of energy or matter.

Transformation: A new product is created. Change of state.

First law or thermodynamics: energy in an isolated system can be transformed but cannot be created or destroyed.

Second law or thermodynamics: is lost in the different levels of a system.

Entropy: is a measure of the amount of disorder in a system.

Negative feedback:

Positive feedback:

PRODUCTIVITY

Is the conversion of energy into biomass over a given period of time.

Biomass: is the living mass of an organism

Gross: total amount of something made as a result of an activity

Gross productivity: in the total gain of energy or biomass per unit area

Gross primary productivity: “” energy fixed by green plants by photosynthesis

Net productivity: is the gain in energy or biomass that remains after deductions due the respiration.

Net primary productivity: is the rate at which plants accumulate dry mass, usually measure in g

Net secondary productivity: only food that crosses the wall of the momentary canal of animals is absorbed and is used to power life processes.

GLOBAL WARMING

+ Feedback: creates change --- speeds up warming (human activity)

-feedback : creates change --- slow down waring (natural)

Forest fires --- release CO2

Volcanic eruption --- release ash

PHOTOCHEMICAL SMOG

Primary pollutants: emitted directly from a process, may be natural (volcan). Produce: Carbon dioxide, monoxide. Nitrogen oxides, Sulphur dioxides

Secondary pollutants: Formed when primary pollutants undergo a variety of reactions with other chemicals already present in the atmosphere. Ex: tropospheric ozone.

What is? Nitrogen dioxide ozone, primary and secondary pollutants.

How does it forms? Motor vehicle exhaust and fossil fuels/ forest burning

Ozone, Nitrogen oxides and Gas of hydrocarbons – sunlight – carbon dioxide + other gases

Point-source pollution is easy to identify. As the name suggests, it comes from a single place. Nonpoint-source pollution is harder to identify and harder to address.