Ecosystems and the Physical

Environment

Chapter 5

Solar Radiation

Solar Radiation

Temperature Changes with Latitude

Like equator Like at poles

Solar Radiation

Temperature Changes with Season

The Atmosphere

Composition

Nitrogen 78%

Oxygen 21%

Carbon dioxideArgonWater vaporPollutantsHeliumEtc.

1%

The Atmosphere

Layers of the

Atmosphere

The Atmosphere

Atmospheric Circulation

Circulation spawned by heating / cooling

Prevailing winds

Generated by pressure differences and Coriolis effect

The Atmosphere

The Coriolis Effect

The Global Ocean

Patterns of Circulation in the Ocean

The Global Ocean

Patterns of Circulation in the Ocean

Influenced by:

1) Coriolis Effect

2) Land Masses

The Global Ocean

Vertical Mixing of Ocean Water

The Global Ocean

• Ocean Interactions with the Atmosphere: Effects of El Nino

• El Nino: periodic warming of tropical eastern Pacific• La Nina: periodic cooling of tropical eastern Pacific

The Global Ocean

Ocean Interactions with the Atmosphere:

Upwelling

This decreases during El Niño

Increases during La Niña

Weather and Climate

Examine the definitions for climate and weather. What is wrong with the following statement?

“Global warming cannot be occurring, we had a very cool summer.”

Weather and Climate

Rain shadows

Insert Fig 5.19 b

Weather and Climate

Severe weather events:

1) Tornados

Source: University of Wyoming, Department of Atmospheric Science

Frequency of tornados annually per 100,000 km2

Tornado Alley (US) 40

Sydney, Australia 8

United Kingdom 1

Bangledesh 0.6

Weather and Climate

Severe weather events:

2) Tropical cyclones

Atlantic Ocean = hurricanes

Pacific Ocean = typhoons

Indian Ocean = cyclones

Weather and Climate

But, all are the same severe weather event:

Internal Planetary ProcessesPlate tectonics Continental Drift

Internal Planetary Processes

Plate boundaries

Internal Planetary Processes

Plate boundaries

Internal Planetary Processes

Volcanoes

Most volcanoes occur along subduction zones

Internal Planetary Processes

Volcanoes

Some occur along spreading zones

Few, such as Hawaiian Islands, not associated with plates. (hot spots)

Internal Planetary Processes

Earthquakes

• caused by release of built up stress, typically along faults

• movement releases seismic waves

Typical side effects include:

1) Landslides

2) Tsunamis

Cycling of Materials within Ecosystems

Basics of biogeochemical cycling

Cycling of Materials within Ecosystems

Hydrologic (water) cycle:

Cycling of Materials within Ecosystems

Carbon cycle:

Cycling of Materials within Ecosystems

Nitrogen cycle:Atmospheric nitrogen (N2)

Nitrogen fixation by humans

Biological nitrogen fixation

Nitrification

NH3 & NH4

-

NO3-

Assimilation

Denitrification

Plant & animal proteins

Decomposition

(ammonification)

Internal cycling

Cycling of Materials within Ecosystems

Phosphorus cycle:

Phosphate rocksPhosphate mining Fertilizer

containing phosphates

Animals, crops

Soil phosphates

Internal cycling

Erosion

Erosion

Dissolved phosphates

Marine organisms

Excretion / decomposition

Internal cycling

Marine sediments

Cycling of Materials within Ecosystems

Sulfur cycle: