Global Climates (Junior Cert Geography): Revision Notes

Global Climates

Factors affecting Global Climates

Climate is the average weather of a large region over a long period. Climate is influenced by various factors that determine temperature, precipitation, and weather patterns in different regions. Below are the key factors affecting climate:

1. Latitude

• Latitude refers to the distance of a place from the equator, measured in degrees.
• Areas closer to the equator receive more direct sunlight, making them warmer.
• The further away from the equator, the cooler the climate becomes due to the angle of the sun's rays.

1. Distance from the Sea

• Maritime climates (coastal areas) are influenced by the sea, which heats up and cools down more slowly than land.
• This results in cooler summers and milder winters, with a small temperature range.
• Continental climates (inland areas) experience more extreme temperatures. Land heats up quickly in summer (warmer) and cools down rapidly in winter (colder), leading to a larger temperature range.

1. Prevailing Winds

• Prevailing winds are the most common winds in an area and can affect temperature and precipitation.
• In Ireland, for example, the prevailing wind is southwesterly, bringing mild and moist conditions.

Types of Climate

Climates can be either temperate, cold or hot climates. Below are some examples of global climates:

Cool Temperate Oceanic Climate

• Location: In mid-latitudes, often found in places like Western Europe (e.g., Ireland).
• Seasons: Four distinct seasons – warm summers and mild winters.
• Weather:
  • Summers are moderate, with temperatures ranging from 15-17°C.
  • Winters are mild, with temperatures around 4-6°C.
  • Rainfall is evenly distributed throughout the year, ranging from 800 to 2,000 mm annually.
• Natural Vegetation: Deciduous forests with trees like oak, ash, and willow, along with ferns and mosses.
• Wildlife: Includes species like red squirrels, deer, and badgers.

Tundra Climate

• Location:: Near the poles, typically in regions like the Arctic and northern parts of Scandinavia.
• Seasons: Two seasons – short, cool summers and long, cold winters.
• Weather:
  • Summers are very short and cool, averaging 5°C.
  • Winters are extremely cold, with temperatures dropping to -35°C.
  • There is a wide annual temperature range, and rainfall is very low (less than 250 mm per year).
• Natural Vegetation: Sparse vegetation including mosses, lichens, and low shrubs.
• Wildlife: Adapted to the cold, such as polar bears and arctic foxes.

Equatorial Climate

• Location: Near the equator, in regions like the Amazon Rainforest.
• Seasons: Only one season – hot and humid year-round.
• Weather:
  • High temperatures throughout the year, averaging around 32°C.
  • Heavy rainfall all year, averaging about 2,000 mm annually.
  • The climate is consistently humid.
• Natural Vegetation: Dense rainforests and jungles, with a wide variety of plant life.
• Wildlife: Rich biodiversity including exotic birds, monkeys, and snakes.