Unit 4: Climate & Biomes

Climate

The long-term pattern of weather conditions in a specific region, including temperature, precipitation, wind patterns, and other factors. It can be influenced by natural processes, such as volcanic eruptions and solar radiation, as well as human activities, such as burning fossil fuels and deforestation.

Weather

The state of the atmosphere at a particular time and place, including temperature, humidity, precipitation, wind speed, and cloud cover.

Climate varies among regions primarily because over long periods of time…

global air circulation + ocean currents distribute heat and precipitation unevenly

Three major factors that affect global air circulation

1. Uneven heating of the earth’s surface by the sun

2. Earth is rotating on its axis

3. Air, land, and water heat at different rates

Uneven heating of the earth’s surface by the sun

• Solar energy strikes Earth at the most direct angle near equator

• At poles, same amount of energy spread over larger surface area

Earth is rotating on its axis

It makes air move in weird ways

Coriolis effect

an apparent deflection caused by the rotation of the earth

• major driver of large scale air and ocean circulation

Air, water, and land heat at different rates

• Heat flows from hot area to cold area

• Hot air rises (think hot air balloon)

• Water is resistant to temperature change

• On a local scale: sea breezes

• On a regional scale: temperature fluctuates less by a body of water (keeps coastal areas cooler)

Hadley (Convection) Cell

a system of circular fluid motion driven by density differences created by uneven heating

• Earth has 6 major atmospheric convection cells

Intertropical Convergence Zone (ITCZ)

zone of clouds and storms near the equator where trade winds meet

Earth’s rotation

→ air is deflected over different parts of the earth (Coriolis effect) → global patterns of prevailing winds → distribute heat and moisture in the troposphere → uneven distribution of heat and moisture over the planets surface → different climates in different places → forests, grasslands, deserts, tundra, etc. → biomes

If heat rises, why are mountains so cold?

Altitude ↑ Temperature ↓

Altitude and topography matters

When surface winds interact with geographical features such as mountains, air is forced into higher altitudes

• temperature ↓, precipitation

Orographic precipitation

Occurs when moist air is forced to rise over elevated terrain, such as mountains. As the air rises, it cools and condenses, forming clouds and eventually leading to precipitation. This process is similar to how air cools when it rises and forms clouds in a hot air balloon. So, orographic precipitation is like rain or snow that happens when air is forced to go up over mountains.

Tropical Desert Biome

• Hot and dry climate

• Sparse vegetation

• Cacti and succulents

• Low rainfall

• High temperatures

• Adapted plants and animals

Temperate Desert Biome

• Hot summers and cold winters

• Low precipitation

• Sparse vegetation

• Drought-resistant shrubs and cacti

• Animals adapted to extreme temperature fluctuations and water scarcity

• Examples: Mojave Desert (North America), Gobi Desert (Asia)

Cold Desert Biome

• Extreme cold temperatures

• Low precipitation

• Found in polar regions and high altitudes

• Sparse vegetation

• Adapted wildlife

Chaparral/Mediteranean Biome

• Characterized by hot, dry summers and mild, wet winters

• Found in regions with a Mediterranean climate

• Drought-resistant plants, including shrubs and small trees, are common

• Plants have adaptations to survive periodic fires

• Known for unique biodiversity and ecological significance

Tropical Grassland (Savanna) Biome

• A biome characterized by grasses and scattered trees.

• Has distinct wet and dry seasons.

• Found in Africa, South America, and Australia.

• Home to a variety of large herbivores, such as zebras and giraffes.

• Fires are common and play a crucial role in maintaining the grassland ecosystem.

Temperate (Deciduous) Forest Biome

• Moderate temperatures and distinct seasons

• Abundant rainfall

• Deciduous trees that lose their leaves in winter

• Diverse plant and animal species

Temperate Grassland (Praire) Biome

• Biome characterized by vast, flat or rolling grasslands

• Few trees, moderate temperatures, and distinct seasons

• Home to a variety of grasses and herbivores

• Examples of animals include bison and prairie dogs

• Fires and grazing are important for maintaining the grassland ecosystem

Cold grassland (Tundra) Biome

• Freezing temperatures and little precipitation

• Low-growing vegetation

• Found near the Arctic and Antarctic circles

• Supports hardy plants like mosses, lichens, and small shrubs

• Home to animals like reindeer, polar bears, and arctic foxes

• Soil is permanently frozen (permafrost)

• Vulnerable to climate change

Tropical Rainforest Biome

• Found near the equator

• High temperatures and abundant rainfall

• Diverse plant and animal species

• Tall trees and dense vegetation

• Complex food webs

• Regulates global climate

• Provides ecosystem services

Temperate Deciduous Forest Biome

• Four distinct seasons

• Moderate temperatures

• Abundant rainfall

• Variety of deciduous trees

• Trees shed leaves in the fall

• Common tree species include oak, maple, and beech

Cold Forest (Taiga/Boreal/Evergeen/Northern Coniferous) Biome

• Found in high-latitude regions.

• Long, cold winters and short, cool summers.

• Dominated by coniferous trees.

• Home to animals like moose, wolves, bears, and lynx, as well as birds like owls and woodpeckers.

• Provides timber resources, helps regulate global climate, and supports unique biodiversity adapted to cold conditions.

Temperate Rainforest (Coastal Coniferous) Biome

• Found in coastal regions with high rainfall and moderate temperatures

• Dominated by tall coniferous trees like spruce, fir, and cedar

• Abundant mosses, ferns, and lichens on the forest floor

• Home to diverse wildlife including bears, deer, and owls

• Important for carbon storage and providing clean air and water

Which biome has deciduous trees (which loose their leaves)?

Temperate/Deciduous Forest

Which biome is the most populated by humans?

Chaparral/Mediterranean

What biome is affected most by humans and development?

Chaparral/Mediterranean

Which biome has permafrost?

Tundra/Polar Grassland

Which biome has coniferous trees (which don't lose their leaves)?

Taiga (Cold Forest/Boreal/Evergeen/Northern Coniferous)