Environmental Science | Atmosphere Flashcards
What is weather?
Weather is the mix of events that happen daily in the atmosphere, including temperature, air pressure, humidity, wind, and precipitation. Most weather occurs in the troposphere.
How does air pressure affect weather?
High pressure: Air flows downward and outward, often causing clear skies.
Low pressure: Air flows upward and inward, leading to cloud formation and precipitation.
What tools are used to measure weather?
Barometer: Measures air pressure.
Doppler radar: Tracks storms.
Weather satellites: Monitor atmospheric changes and water vapor.
What are air masses, and how are they classified?
Large bodies of air with uniform temperature and moisture:
Maritime Polar (mP): Cold, moist air from over oceans.
Continental Polar (cP): Cold, dry air from land.
Maritime Tropical (mT): Warm, moist air from equatorial oceans.
Continental Tropical (cT): Hot, dry air from land.
What happens when air masses collide?
They form fronts, creating distinct weather patterns:
Cold Fronts: Cold air pushes warm air up, forming thunderstorms.
Warm Fronts: Warm air rises over cold air, leading to prolonged drizzle.
Stationary Fronts: Stalemate between air masses, causing extended overcast and rain.
Occluded Fronts: Complex interactions of cold and warm air masses, leading to mixed precipitation.
How does Earth’s tilt affect seasons?
The tilt causes varying solar radiation:
Summer: Hemisphere tilted toward the Sun.
Winter: Hemisphere tilted away.
Spring/Autumn: Sun shines equally on both hemispheres.
What is the Coriolis Effect?
The rotation of Earth causes winds to curve:
Northern Hemisphere: Winds curve to the right.
Southern Hemisphere: Winds curve to the left.
Describe how carbon cycles through Earth and the atmosphere.
Fast cycle: Between atmosphere, plants, animals, and soils.
Slow cycle: Involves oceans, sediments, and volcanoes.
How do human activities impact the nitrogen and phosphorus cycles?
Overuse of fertilizers disrupts ecosystems by adding excess nutrients, leading to water pollution and algal blooms.
What causes Earth’s atmosphere to stay in place?
Gravity pulls atmospheric gases toward Earth’s surface, creating air pressure.
What is air pressure, and how is it measured?
Definition: The force exerted by air molecules above a specific area.
Measurement tools: Barometer (inches of mercury or millibars).
How do temperature and density affect air pressure?
Warm air: Lower density and lower pressure as molecules spread out.
Cold air: Higher density and higher pressure as molecules compress
How has the atmosphere evolved over time?
Early atmosphere: Dominated by volcanic CO₂ and water vapor.
Algae and plants: Reduced CO₂ and increased oxygen through photosynthesis.
Current atmosphere: Balanced due to natural cycles and human impacts.
What role do nitrogen-fixing bacteria play in the nitrogen cycle?
They convert atmospheric nitrogen (N₂) into ammonia (NH₃) or ammonium (NH₄⁺), making it usable by plants.
What is denitrification, and why is it important?
Definition: The process of converting nitrate (NO₃⁻) back into nitrogen gas (N₂).
Importance: Balances nitrogen levels in ecosystems and prevents overaccumulation.
How does the phosphorus cycle differ from other biogeochemical cycles?
It does not involve the atmosphere. Phosphorus originates from weathering rocks and cycles through soil, water, and organisms.
What are the characteristics of a cold front?
Definition: Cold air rapidly pushes under warm air, causing it to rise.
Weather: Thunderstorms, high winds, and cumulonimbus clouds.
Symbol: Blue triangles pointing toward warm air.
What are the characteristics of a warm front?
Definition: Warm air slowly rises over cooler air.
Weather: Drizzle and overcast skies.
Symbol: Red semicircles pointing toward cooler air.
What are occluded fronts, and how do they form?
Definition: Formed when a cold front overtakes a warm front.
Weather: Mixed precipitation and overcast skies.
Symbol: Purple line with alternating triangles and semicircles.
What is a stationary front?
Definition: Occurs when warm and cold air masses meet but do not move.
Weather: Prolonged drizzle and cloudy skies.
Symbol: Alternating blue triangles and red semicircles on opposite sides of a line.
What are Hadley, Ferrel, and Polar cells?
Hadley cells: Circulation between the equator and 30° latitude, creating tropical rainforests and deserts.
Ferrel cells: Between 30° and 60° latitude, mixing tropical and polar air.
Polar cells: Cold, sinking air at the poles creates dry, high-pressure zones.
How does the tilt of Earth’s axis affect the intensity of solar radiation?
Direct sunlight at the equator causes consistent warmth.
Indirect sunlight at higher latitudes creates seasonal variations.
How do human activities alter the carbon cycle?
Burning fossil fuels adds CO₂ to the atmosphere.
Deforestation reduces the amount of CO₂ absorbed by plants.
Oceans absorb CO₂, causing acidification and threatening marine ecosystems.
What are the main causes of global wind patterns?
Unequal heating of Earth’s surface.
Earth’s rotation and the Coriolis effect.
Convection currents from rising warm air and sinking cool air.