Weather Idea #1 – Air Pressure
• Air particles surround the Earth
• Their ‘weight’ presses down on the Earth, creating air pressure.
Weather Idea #2 – Air particle density and air pressure
• High Pressure = High Density Air (particles crowded together)
• Low Pressure = Low Density Air (particles spread apart)
Weather Idea #3 – Air Temperature
Air particles are in motion - the more the particles move, the higher the temperature.
Weather Idea #4 – Uneven heating of the Earth affects air temperature & air pressure
• Warmed air rises and expands upward = low pressure (particles spread apart - low density) - L
• Cooled air sinks and compresses against Earth’s surface = high pressure (particles crowded together - high density) – H
Weather Idea #5 – Humidity
• Some of the air particles in our atmosphere are water vapor.
Weather Idea #6 – Adiabatic changes in temperature
• High Pressure = Dry, Fair Skies - Compressed sinking air heats up (adiabatic heating) leading to evaporation
• Low Pressure = Cloudy with a chance of rain - Expanding rising air cools down (adiabatic cooling) leading to condensation
Weather Idea #7 – The Wind
• Wind is the movement of air from high pressure to low pressure.
• The bigger the difference in pressure, the stronger the wind will be.