Unit 2 Review: Weather and Climate

Unit 2 Review: Weather and Climate

• Six factors affecting climate: Earth in space, differential heating of land and water, ocean currents, air masses, relief barriers, and global pressure belts.

Earth's Orbit and Climate

• Diagrams show Earth's orbit around the Sun.
• Diagrams illustrate the month and seasonal events (equinoxes and solstices).
• Earth's tilt impacts the amount of solar radiation received, influencing climate.
• As the Earth tilts away from the Sun, the height of the Sun in the sky decreases, leading to less solar radiation.

Angle of Incidence and Climate

• Greater angle of incidence means more surface area covered by the same amount of radiation, due to Earth's curvature.
• Greater angle of incidence results in more atmosphere for the sun's radiation to pass through, leading to reflection. This results in less solar radiation reaching polar regions.

Greenhouse Effect

• The greenhouse effect is beneficial.
• Without it, the average global temperature would be -18°C.

Solar Radiation Budget

• Solar radiation budget describes the fate of solar radiation when it reaches Earth.
• About 50% of solar radiation reaches Earth's surface.
• Earth's atmosphere is, in a sense, heated more by Earth than by the Sun.

Differential Heating

• Land and water bodies store solar energy differently.
• Land absorbs heat quickly but also radiates it quickly; water stores heat slowly, releasing it slowly.
• This difference creates continental and maritime climates.
• Climate graphs for continental climates show wider temperature ranges; maritime climates exhibit moderate temperatures.

Ocean Currents

• Warm currents increase humidity and precipitation; Cold currents reduce coastal humidity.
• Four major ocean currents influencing North American climate: West Coast (Alaska & California) and East Coast (Gulf Stream & Labrador), each identified as either warm or cold.

Air Masses

• Air masses are large parcels of air with shared characteristics (moisture, pressure, temperature).
• Air masses can carry weather systems long distances.

Fronts

• Fronts are boundaries between unlike air masses.
• The degree of difference between clashing air masses determines the storm's intensity.
• The speeds of the air masses influence the length of the storm.

Fronts (cont.)

• Cold fronts bring violent, short, heavy showers.
• Warm Fronts bring gentle, longer lasting showers.

Altitude and Climate

• Adiabatic cooling occurs when air rises, expands, and cools.
• Adiabatic warming occurs when air descends, compresses, and warms.

Mountains and Climate

• Mountains can block air mass movement, isolating climates.
• Mountain barriers can modify air masses.

Orographic Precipitation

• Orographic precipitation results from air masses rising over mountains, cooling and condensing, forming clouds and precipitation.
• Dry and wet adiabatic lapse rates describe the rate of cooling as elevation increases (with and without condensation effects).

Pressure Systems

• High pressure systems are cool, descending, and associated with clear skies.
• Low-pressure systems are warm, moist, rising, and associated with cloudiness and potential precipitation.

Isobars

• Isobars connect points of similar air pressure.
• Closely spaced isobars indicate steep pressure gradients (rapid pressure changes), signifying stormy conditions.
• Widely spaced isobars indicate gentle pressure gradients, implying fair weather.

Convection Currents

• Convection currents are loops of air moving from warm air (rises) to cold air (sinks).
• Three major convection cells are Polar, Ferrel, and Hadley, each associated with specific latitude bands.

Global Pressure Belts

• High and low pressure belts exist globally, driving wind patterns.
• High pressure systems at approximately 30° latitude are associated with deserts due to descending, dry air.

El Niño

• El Niño is a climate pattern associated with a bulge of warm water across the Pacific Ocean.
• It produces significant changes in weather patterns around the globe.
• Impacts include flooding in some regions and droughts in others, migration of people, and even collapse of civilizations in the past.

Coriolis Effect

• The Coriolis effect causes winds in the northern hemisphere to deflect to the right.