Presentation on theme: "General Atmospheric Circulation V1003 - Science and Society."— Presentation transcript:
General Atmospheric Circulation V1003 - Science and Society
Take away concepts and ideas The Earth is heated unevenly. Why there are seasons. Global-scale wind patterns. Geostrophic flow: Balance of forces that act on atmospheric flow (Pressure gradients & gravity balanced by Coriolis force) Wind belts and climate zones. Monsoonal climate.
1.As a sphere, the Earth is unevenly heated, equator to poles
Pressure imbalance = flow 1. Pressure imbalance is a FORCE (F = m x a) 2. Law of mass continuity (empty spaces not tolerated in fluids)
Earth’s uneven radiation 1.Earth is a sphere (uneven radiation) 2.Tilted (there are seasons) Sphere means equator gets more radiation than poles. Tilt mean the amount of radiation at one location changes with time (seasons).
Q1: Knowing uneven heating and P = R T a)Poles have low density, equator has high density? b) Equator has low density, poles have high density?
BUT - The Earth rotates Apparent (inertial) forces control the flow of air in response to these pressure gradients. Centripedal force is the force acting on body by string Centrifugal force is the opposite force acted on by the ball (by its own inertia)
Imagine a satellite in orbit Centripetal force = Gravity Centrifugal force = mass and acceleration of satellite Exact balance sets the angular velocity of the satellite
The Coriolis Force Artifact of Earth’s rotation An apparent force which acts on motion on the earth’s surface Conservation of angular momentum F coriolis = 0 on equator, increases poleward