Key Concepts in Climate and Weather Patterns

Climate

The average weather conditions in a place over a long period (usually 30+ years).

Climatology

The study of climate and how it changes over time.

Weather

The day-to-day conditions of the atmosphere (like rain, sun, or temperature).

World Temperature Controls

Factors like latitude, elevation, ocean currents, and nearby water bodies that affect temperatures around the world.

Precipitation

Any form of water that falls from the sky (like rain or snow).

Warm vs Cold Ocean Currents and Effect on Precipitation

Warm currents increase humidity and rainfall; cold currents dry the air, reducing rainfall.

cT (continental Tropical)

Hot and dry air from land areas.

mT (maritime Tropical)

Warm and humid air from oceans.

mP (maritime Polar)

Cool and moist air from cold oceans.

cP (continental Polar)

Cold and dry air from land in polar regions.

Frontal Uplift

When warm and cold air meet, warm air rises.

Orographic Uplift

Air rises over mountains, cools, and drops rain.

Convectional Uplift

Warm ground heats air, causing it to rise and form rain clouds.

Climate Region

A large area with similar climate patterns.

Sahel

A dry grassland region south of the Sahara Desert, prone to drought.

Dust Bowl

A 1930s U.S. event where drought and poor farming caused severe dust storms.

Desertification

The spread of deserts due to climate change or poor land use.

Desert Climates

Located around 30°N and 30°S; very dry with little rain.

Tropical Monsoon Climates

Seasonal winds bring heavy rain; linked to the Intertropical Convergence Zone (ITCZ).

Tropical Savannah Climate

Warm year-round with dry and wet seasons; also affected by the ITCZ.

Boreal Forest (Taiga)

Cold, snowy winters and short, cool summers; large temperature changes yearly.

Mediterranean Climate

Mild, wet winters and hot, dry summers.

Mediterranean Dry Summer Climates

Caused by subtropical high pressure in summer; hot, dry summers and mild winters.

Highland Climates

Found in mountains; colder temperatures due to elevation.

Tundra

Cold, treeless region near the Arctic with short summers.

Permafrost

Soil that stays frozen year-round.

Polar Climate

Very cold with low precipitation (often snow).

Intensive Agriculture

Farming that uses lots of labor or resources to get high crop yields.

Slash and Burn Agriculture

Cutting and burning forest to create farmland.

Intercropping

Growing different crops together on the same land.

Carrying Capacity

The maximum number of people or animals an area can support sustainably.

Keeling Curve

A graph showing rising CO₂ levels in the atmosphere over time.

Indicators of Climate Change

Signs include rising global temperatures, melting glaciers, rising sea levels, and shifting weather patterns.

Why are latitude and location (Maritime or continental) important in determining the annual temperature cycle of a station?

• Latitude affects the angle and intensity of solar radiation.

• Higher latitudes have larger temperature variations.

• Maritime locations have moderate temperatures due to water’s heat retention.

• Continental locations heat and cool faster, causing more extreme seasonal changes.

Why is the annual temperature cycle of the Tropical Rainforest climate so uniform?

• Located near the equator with consistent sunlight year-round.

• Daily convectional rainfall keeps temperatures stable.

• Constant humidity moderates temperature swings.

What sides of continents is the Tropical Monsoon climate found and why?

• Found on the eastern sides of continents near the equator.

• Caused by shifting winds from the ITCZ (Intertropical Convergence Zone).

• Summer: wet monsoon winds from oceans.

• Winter: dry winds from interior landmasses.

What type of environment do the Tropical Rainforest and Tropical Monsoon climates produce and why?

• Lush, dense vegetation.

• High biodiversity.

• Caused by heavy rainfall and warm temperatures.

Most common agricultural system in these regions?

• Slash and burn (shifting cultivation).

• Also: rice farming in monsoon areas.

Tropical Savanna Climate: What causes dry and wet seasons?

• Seasonal movement of the ITCZ.

• Wet season: ITCZ brings moisture-laden winds.

• Dry season: Subtropical high-pressure systems dominate.

• Environment: Grasslands with scattered trees.

Humid Subtropical Climate (Hot summer): Why found on eastern continents in midlatitudes?

• Affected by warm ocean currents and moist maritime air.

• Summer: High temps and humidity from maritime tropical (mT) air.

• Winter: Cool, drier continental polar (cP) air.

Mediterranean vs Marine West-Coast Climates: Why more winter precipitation?

• Both influenced by westerlies and ocean currents.

• Winter: Low pressure brings storms and rain.

• Summer: Subtropical highs block storms.

• Differences:

  • Mediterranean: Hot dry summers, mild wet winters.

  • Marine West-Coast: Mild summers and winters, steady rain year-round.

Subtropical High-Pressure Cells: Affected climates and their effects

• Affect: Deserts, Mediterranean, Savannah, and Monsoon climates.

• Block moisture during summer, causing dry seasons.

• Push storms northward or southward depending on the season.

Four desert classifications and how they're different:

• Subtropical deserts: Hot, dry all year (e.g., Sahara).

• Midlatitude deserts: Drier due to rain shadow (e.g., Great Basin).

• Cold deserts: Cold temps, low precipitation (e.g., Gobi).

• Coastal deserts: Cool ocean currents, fog but little rain (e.g., Atacama).

• Classified by moisture availability and temperature.

Coldest places on Earth outside the poles:

• Found in high-altitude continental interiors (e.g., Siberia, Tibet).

• Very cold winters due to lack of oceanic influence.

• Low precipitation (cold deserts).

Scientific tools used to study paleoclimatology:

• Ice cores.

• Tree rings (dendrochronology).

• Ocean and lake sediment cores.

• Pollen records.

• Coral growth rings.

What is a climate proxy?

• An indirect measure of past climate.

• Example: Ice cores show atmospheric CO₂ and temperature levels.

Natural factors influencing Earth's climate:

• Solar radiation changes (sunspot cycles).

• Volcanic eruptions (release aerosols that cool the Earth).

• Earth’s orbital changes (Milankovitch cycles).