Generally, over low pressure area the air will converge and rise.

Over high pressure area the air will subside from above and diverge at the surface.

What is the General Circulation of the Atmosphere?

The General Circulation of the Atmosphere, also known as atmospheric circulation, is a large-scale movement of air that helps in distributing thermal energy (heat) across the surface of the Earth. This circulation is a fundamental aspect of the Earth’s climate and weather systems. Here are its key components and dynamics:

1. Heat Distribution: The Earth receives uneven heating from the sun due to its spherical shape and tilt. The equatorial regions receive more direct sunlight and are warmer compared to the polar regions, which are cooler.

2. Cell Circulation: This temperature difference creates three main circulation cells in each hemisphere: the Hadley cell, Ferrel cell, and Polar cell. These cells are responsible for the large-scale wind patterns on Earth.

• Hadley Cell: Located between the equator and 30° N/S latitude. Warm air rises at the equator, cools as it moves poleward, and sinks at around 30° N/S, creating trade winds in the tropics.

• Ferrel Cell: Found between 30° and 60° N/S latitude. It is characterized by westerly winds and is responsible for much of the weather in the mid-latitudes.

• Polar Cell: Occurs from 60° to the poles. Cold air sinks at the poles and flows towards lower latitudes.

3. Coriolis Effect: Due to the Earth’s rotation, moving air is deflected to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. This effect shapes the direction of wind patterns.

4. Jet Streams: High-altitude, fast-moving air currents that significantly influence weather patterns. They typically flow along the boundaries of the Hadley and Ferrel cells.

5. High and Low-Pressure Systems: These systems are formed due to varying temperatures and the Earth’s rotation, driving the global wind patterns.

6. Oceanic Influence: The ocean currents also play a crucial role in distributing heat and influencing climate and weather patterns.

What is Geostrophic wind?

A theoretical wind that would result from an exact balance between the Coriolis effect and the pressure gradient force. This condition is called geostrophic balance. The geostrophic wind is directed parallel to isobars (lines of constant pressure at a given height).