The World Climate Notes with PDF

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Factors Influencing Climate and Weather

Causes of Day-Night Variation

• The seasonal variation in the length of day and night is caused by:
  • The revolution of the Earth around the Sun.
  • The latitudinal position of a place.
• Note: The Earth’s rotation on its axis causes the daily cycle of day and night, but not the seasonal variation in their length.

Factors Affecting Temperature

• The annual range of temperature is much higher in continental interiors compared to coastal areas.
  • Primary Reason: The thermal difference between land and water; land heats up and cools down faster than water.
• The main factor that determines the climate of any area is its latitude.

World Climatic Zones

Equatorial Climate

• Location: Found between 5° to 8° latitude on either side of the equator.
• Countries: Congo, Gabon, Zaire.
• Characteristics:
  • Rainfall throughout the year.
  • Very low average annual temperature range.
  • Typical daily weather: clear mornings, buildup of heat, formation of dark clouds by afternoon, followed by convectional rainfall with thunder and lightning.
  • Highly conducive for plant growth but can be challenging for humans.
• Exception: Ethiopia does not have a typical equatorial climate due to its highland topography.

Tropical Savannah (Sudan) Climate

• Characterized by: A definite dry season and a wet season.
• It does not have rainfall throughout the year.

Mediterranean Climate

• Characteristics:
  • Summers: Warm and dry.
  • Winters: Mild and wet.
  • Vegetation includes evergreen oak trees.
• Found in:
  • Central Chile
  • Cape Town (South Africa)
  • Adelaide (Australia)
  • California (USA)
  • Rome (Italy)
• Not found in:
  • The Pampas of Argentina (which has a temperate climate).
  • New York (which has a humid continental climate).

Steppe Climate

• Description: Extreme climate with scanty rainfall.
• Historically, the people in these regions were nomadic herders.
• This best describes the Central Asian Steppe region.

Desert Climate

• Arid regions cover the maximum percentage of the Earth’s surface among the given options.

Regional and Seasonal Rainfall Patterns

Monsoon Climate

• Found in: Bangladesh.
• Characterized by: A distinct seasonal pattern, not heavy rain all year.

Winter Rainfall

• Rainfall in the winter season is a defining feature of the Mediterranean climate (e.g., Italy).
• Other examples:
  • Norway experiences significant winter precipitation (often as snow).
  • Chile (specifically its central zone) has a Mediterranean climate with winter rain.
• Not a characteristic of:
  • China (dominated by summer monsoon).
  • Brazil (varies, but largely summer rains).
  • Nigeria (summer rains).

Continent-Wide Climate Patterns

• The continent of Asia has all types of climatic zones due to its vast size and latitudinal extent.

Detailed Climate Type Analysis

Equatorial Climate

• Example: Congo basin.
• Characteristics: Rainfall throughout the year (no distinct dry season).
• Correction: The year is not divided into four main seasons.

Mediterranean Climate

• Example: California.
• Characteristics: Rainy winters and dry summers.
• Cause: Rainy winters are due to the shift in global wind belts, placing the region under the influence of the Westerlies during winter.
• Correction: Summer does not receive more rain.

Monsoon Climate

• Example: Bangladesh.
• Characteristics: Highly seasonal rainfall.
• Cause: Associated with the shifting of planetary pressure belts.
• Correction: Rainfall does not necessarily occur all year.

Savanna Climate

• Example: Sudan.
• Characteristics: A tropical grassland climate with a distinct wet and dry season.

China-Type Climate

• Characteristics: A temperate climate where rainfall occurs throughout the year. Data shows warm summers and cool, wet winters.

Western European / Marine West Coast Climate

• Characteristics: Rainfall throughout the year with a mild temperature range. Cool summers, mild winters, and no dry season.
• Ports in Northwest Europe are open year-round due to the moderating influence of the South-Westerly winds and the North Atlantic Drift.

Global Climate Extremes

Wettest Place

• Mawsynram (India) is the wettest place on Earth. Cherrapunji is also known for very high rainfall.

Coldest Place

• Verkhoyansk (Russia) is one of the coldest places on Earth.

Hottest and Driest Places

• Hottest Place: Sahara Desert.
• Driest Place: Atacama Desert (Chile).
• Coldest Continent: Antarctica.

Climatic Phenomena

El Niño and La Niña

• El Niño:
  • Develops in the Pacific Ocean.
  • Characterized by unusually warm ocean temperatures in the equatorial Pacific.
  • Has an adverse effect on the Southwest Monsoon in India.
• La Niña:
  • Characterized by unusually cold ocean temperatures in the equatorial Pacific (not the Indian Ocean).
• Both are associated with short-term climatic predictions and can affect monsoon rains.

Pressure Belts and Winds

• Climates like the Mediterranean and Monsoon are associated with the shifting of planetary pressure belts.
• The Westerlies are a dominant wind belt influencing European and Mediterranean climates.

Climate Identification from Data

• Cool summers, mild winters, rainfall throughout the year with a winter maximum: Indicative of the Western European type.
• Hot, dry summers and mild, rainy winters: Indicative of the Mediterranean type.
• Sharp peak in summer rainfall and high summer temperatures: Indicative of the Monsoon type (e.g., China type).

Ecological Terms

• Hekistotherms: Plants that grow in very low-temperature conditions (e.g., in alpine or polar regions).

Know More About The World Climate:

• The World Climate – Old Year Questions
• The World Climate One Liner Questions & Answers