Midterm Weather Flashcards
(22 cards)
Describe air movement
Warm air rises; cool air sinks.
Why does warm air rise and cool air sink?
Warm, moist air is less dense than cold, dry air.
Describe phase changes in climate
Require energy gain or loss (e.g., melting, freezing, evaporation, condensation).
Explain what is required for a substance to undergo a phase change (weather)
For a substance to undergo a phase change, like in weather conditions, it needs to gain or lose energy (usually in the form of heat), which can be achieved by a change in temperature, and sometimes also a change in pressure, allowing the molecules to rearrange and transition between states like solid, liquid, and gas; examples include melting ice (solid to liquid), water evaporating (liquid to gas), or condensation forming on a cold surface (gas to liquid).
Describe the most common phase changes (weather)
Evaporation: Liquid water turns into water vapor when it gains heat from the environment.
Condensation: Water vapor in the air turns back into liquid droplets when it loses heat, forming clouds.
Freezing: Liquid water turns into ice when it loses heat.
Melting: Ice turns into liquid water when it gains heat.
Sublimation: Ice directly changes into water vapor without going through the liquid phase (occurs in cold, dry environments).
Describe what influences air pressure
Higher elevation = lower pressure.
Warmer temperature = lower pressure.
More humidity = lower pressure.
How do clouds form?
Water vapor in the air condenses to form liquid water or ice crystals. Water vapor cools
Cirrus
Cumulus
Stratus
What causes wind?
Caused by differences in air pressure; moves from high to low pressure.
What direction does local wind always blow?
Generally, winds across most of the globe blow from west to east due to the Earth’s rotation and the Coriolis effect.
What causes global wind patterns?
Air moves between equator and poles due to temperature differences. Global winds do not follow a straight path due to coriolis effect
What are air masses?
Large bodies of air that have similar temperature, humidity, and air pressure
What properties are used to describe an air mass?
An air mass is primarily described by its temperature and humidity properties, which are determined by the place where it forms;
Tropical: warm - forms over a warm ocean,
Polar: cold - forms north of 50 degrees north or south of 50 degrees south (polar regions)
Maritime: forms over oceans (humid)
Continental: forms over land (drier)
What is Coriolis effect?
The effect of convection and Earth’s rotation causes global winds to have a swirling pattern
What occurs when air masses interact?
Air fronts are large bodies of air with uniform temperature and humidity. When air masses meet, they cause storms and weather changes.
What are the types of air fronts?
The four main types of air fronts arecold, warm, stationary, and occluded.
Describe a cold air front
Fast colder air mass that moves into slow warmer air mass
causes rapid temperature changes
can cause thunderstorms as the warm air rises over the cold air
Describe a warm air front
Fast warm air mass that rises over slow cooler air,
causing clouds and light to moderate precipitation, such as rain, sleet, snow, or drizzle and gradual temperature changes
Describe a stationary air front
The boundary between two air masses that are not moving (cold and warm), can stay in place for days
Can be days of clouds or rain
Describe an occluded air front
Formed when a warm air mass is caught between 2 cooler air masses
Weather gets cooler
can bring rain or snow
What is a greenhouse gas?
Greenhouse gases are carbon dioxide, methane, and water vapor)
They make up only 1% of the atmosphere
They absorb heat (keep earth warm)
How does the greenhouse effect work to keep Earth’s climate stable?
The greenhouse effect works by trapping heat from the sun in Earth’s atmosphere through certain gases, known as greenhouse gases, which absorb infrared radiation emitted by the planet, preventing it from escaping back into space and thus maintaining a relatively stable temperature on Earth, allowing life to exist as we know it; essentially acting like a blanket around the planet.
Describe Earth’s energy budget
Balance of energy from the Sun absorbed and radiated by Earth. The balance between the amount of solar energy coming into Earth from the sun and the amount of energy that Earth radiates back out into space, essentially describing how much energy enters and leaves the planet at any given time, maintaining a stable temperature if balanced; if more energy comes in than leaves, the Earth warms, and vice versa.
