Weather Systems and Climate Factors

Temperature and Pressure Systems

• Low Pressure (LP): High temperature, rising air, converging air, clockwise movement, cloud formation, and wet conditions.
• High Pressure (HP): Low temperature, sinking air, diverging air, anti-clockwise movement, dry conditions.
• Cyclones: Low pressure systems with rising air, converging air, and clockwise rotation in the Northern Hemisphere; associated with cloud formation and wet conditions.
• Anticyclones: High pressure systems with sinking air, diverging air, and counter-clockwise rotation in the Northern Hemisphere; associated with dry conditions.

Unequal Heating of the Atmosphere

• Earth is heated by incoming solar radiation (insolation).
• The amount of heat energy in the atmosphere depends on insolation, which varies based on latitude and season.
• Insolation is affected by latitude (angle at which sunlight strikes the Earth's surface) and season (the Earth's tilt relative to the sun).

Latitude

• The angle at which the sun's rays strike the Earth's surface varies with latitude.
• Higher latitudes receive solar radiation at a lower angle, resulting in a larger surface area covered by the same amount of energy, leading to less heat energy per unit area.
• Lower latitudes receive solar radiation at a steeper angle, resulting in a smaller surface area covered by the same amount of energy, leading to more heat energy per unit area.

Unequal Heating and Seasons

• Seasons are caused by the tilt of the Earth's axis relative to its orbital plane around the sun.
• In the northern hemisphere, winter occurs when the Earth's axis is tilted away from the sun.
• In the southern hemisphere, winter occurs when the Earth's axis is tilted towards the sun

Heating Imbalances Due to Latitudinal Differences

• Incoming solar radiation and outgoing radiation are not balanced everywhere on Earth.
• Some areas receive more radiation than they lose (surplus), while others lose more radiation than they gain (deficit).
• The amount of radiation surplus equals the amount of radiation deficit, balancing the overall energy on Earth.

Mechanisms Responsible for Poleward Transfer of Energy

• Winds: Warm, moist air moves from the tropics to the poles, carrying heat energy.
• Ocean currents: Currents in oceans transport warm water to colder regions and vice versa, transferring heat energy.
• Deep ocean currents: Driven by differences in water density (cold, salty water is denser), these currents further contribute to the Earth's heat distribution.

Currents

• Surface currents: In the Northern Hemisphere, these currents circulate clockwise, and in the Southern Hemisphere circulate counter-clockwise.
• Warm and cold currents transport warm water towards the poles and cold water toward the equator, respectively.

Energy Transfer by Wind

• Wind is moving air that transports heat from lower to higher latitudes.
• Winds are part of the global circulation.
• Winds redistribute heat from the tropics to the poles.

Unicellular Model of Global Circulation

• The model depicts three large-scale atmospheric circulation patterns on Earth: Hadley, Ferrel, and Polar cells.

World Pressure Belts

• Pressure belts are arranged in an alternating pattern of high and low pressure around the Earth.
• These variations are associated with temperature differences.
• The pressure belts form distinct patterns in each hemisphere, which are similar but not identical. This is due to interactions of air circulation.

Three-Cell Circulation Model

• Equatorial Low: A region of low pressure associated with rising air near the equator.
• Subtropical Highs: Regions of high pressure associated with sinking air in the subtropics, leading to clear skies and little precipitation.
• Polar Low/Polar Highs: Regions of low pressure associated with rising, cold air near the poles; high pressure is associated with sinking, dense, cold air.

Three-Cell Circulation Model - Surface Winds

• Easterly winds: Tropical easterlies form part of Hadley cells and blow from tropical high pressure belts toward low pressure near the equator.
• Westerly winds: Part of the Ferrel cells and blow from the sub-tropical high-pressure belts towards the sub-polar low-pressure belts in both hemispheres.
• Polar easterlies: Originate from the polar cells and blow toward the subpolar lows.

Additional Features

• Global Circulation: The large-scale movement of air around the Earth, driven by temperature differences.
• Tropopause: The boundary between the troposphere and the stratosphere in the atmosphere.
• Global Winds: Prevailing wind patterns like the trade winds, westerlies, and polar easterlies across the globe.
• Latitude and Temperature: The amount of solar energy received varies across different latitudes, which affects local temperature.
• Pressure Belts and Winds: The pressure belts influence wind patterns due to pressure gradients.

Explore the dynamics of temperature and pressure systems, including low and high pressure systems, cyclones, and anticyclones. Understand how unequal heating of the atmosphere affects weather patterns, influenced by latitude and seasonal changes. Test your knowledge on how these atmospheric factors interact and impact the climate.