Ocean currents

  1. Ocean currents are large-scale movements of water within the world's oceans, driven by various forces.
  2. They play a critical role in regulating climate and distributing heat across the planet.
  3. Ocean currents are broadly categorized into surface currents and deep-water currents.
  4. Surface currents are primarily driven by wind and cover the upper layer of the ocean.
  5. Deep-water currents, also known as thermohaline circulation, are driven by differences in wate

Climate change

  1. Climate change refers to significant, long-term changes in the Earth’s climate patterns.
  2. It is driven by both natural factors and human activities.
  3. Key natural factors include volcanic eruptions, variations in solar radiation, and changes in Earth’s orbit.
  4. Human-induced climate change is primarily caused by the release of greenhouse gases (GHGs) like carbon dioxide, methane, and nitrous oxide.
  5. Burning of fossil fuels, de

Clouds and precipitation

  1. Clouds are visible masses of tiny water droplets or ice crystals suspended in the atmosphere.
  2. They form when air rises, cools, and reaches its dew point, leading to condensation.
  3. Condensation nuclei, such as dust and pollen, are essential for cloud formation.
  4. Clouds are classified based on their appearance, altitude, and formation process.
  5. The primary cloud types are cirrus, cumulus, stratus, and nimbus.

Pressure belts and winds

  1. The Earth’s atmosphere is divided into distinct pressure belts due to uneven heating of its surface.
  2. There are seven pressure belts around the Earth: Equatorial low, Subtropical highs (two), Subpolar lows (two), and Polar highs (two).
  3. The Equatorial low-pressure belt, or the doldrums, lies around the equator (0°-5° latitude).
  4. This region experiences intense solar heating, causing air to rise and creating low pressure.
  5. The Subtropical high-pressure belts are located aroun

Weather and climate

  1. Weather refers to the short-term atmospheric conditions of a specific place at a specific time.
  2. Climate is the average weather pattern of a region over a long period, typically 30 years or more.
  3. Weather elements include temperature, humidity, precipitation, wind, and atmospheric pressure.
  4. Climate factors include latitude, altitude, proximity to water bodies, and ocean currents.
  5. Weather is highly variable and can change within hours or days.
  6. Climate

Atmosphere

  1. The atmosphere is a mixture of gases surrounding the Earth, essential for sustaining life.
  2. It consists of 78% nitrogen, 21% oxygen, and 1% other gases, including argon, carbon dioxide, and trace gases.
  3. The atmosphere is divided into five layers based on temperature variations.
  4. Troposphere: The lowest layer, where most weather phenomena occur and life exists.
  5. The average height of the troposphere is about 12 km, but it va

Major geomorphic features

  1. Geomorphic features are landforms created by internal and external forces shaping the Earth's surface.
  2. These features are classified into primary (endogenic) and secondary (exogenic) landforms.
  3. Primary landforms are formed by tectonic activities like mountain building, volcanism, and faulting.
  4. Mountains: Elevated landforms created by tectonic forces, classified as fold, block, volcanic, or residual mountains.
  5. Fold mountains: Formed by compressional force

External processes

  1. External processes are geomorphic activities that originate from forces outside the Earth's surface.
  2. These processes are also called exogenic processes.
  3. They include weathering, erosion, transportation, and deposition.
  4. External processes are driven by solar energy, gravity, and the hydrological cycle.
  5. Weathering is the breakdown of rocks into smaller particles through physical, chemical, or biological means.
  6. Physical weat

Solar system

  1. The Solar System consists of the Sun, eight planets, moons, dwarf planets, asteroids, comets, and other celestial objects.
  2. The Sun is the center of the Solar System and accounts for 99.86% of its total mass.
  3. The eight planets are classified as terrestrial planets (Mercury, Venus, Earth, Mars) and gas giants (Jupiter, Saturn) and ice giants (Uranus, Neptune).
  4. Mercury is the closest planet to the Sun and has no atmosphere to retain heat.
  5. Venus

Earth's motions

  1. The Earth has two primary motions: rotation and revolution.
  2. Rotation refers to the Earth spinning on its axis.
  3. The Earth completes one rotation in approximately 24 hours, causing day and night.
  4. The axis of rotation is tilted at an angle of 23.5° relative to the plane of its orbit.
  5. Revolution refers to the Earth's orbit around the Sun.
  6. One complete revolution takes approximately 365.25 days, leading to the concept of a year.