Unit 2: Climate Change and Hurricanes

Vocabulary flashcards covering key terms from the lecture notes on hurricanes, climate change, and related concepts.

Hurricane (Tropical Cyclone)

A rapidly rotating storm system formed over warm tropical waters with a low‑pressure center (the eye) and heavy rainfall; winds ≥74 mph; called a hurricane in the Atlantic and NE Pacific (typhoon in the NW Pacific). Diameter roughly 100–2,000 km.

Eye of the Storm

The calm center of a hurricane where descending air creates relatively clear conditions, surrounded by the intense eyewall.

Low-Pressure Center

Central area of a hurricane with low atmospheric pressure that draws in surrounding air and fuels the cyclone.

Warm Water Requirement

Water temperatures of at least 80°F (≈27°C) and warm water depth of at least 160 feet are needed to form hurricanes.

Energy Source

Evaporation of warm ocean water; water vapor rises, condenses into clouds, and falls as rain, powering the storm.

Hurricane Season Dates

June 1 to November 30; peak activity typically in September when ocean waters are warmest.

Wind Speed Threshold

Sustained winds exceeding 74 mph define a hurricane.

Formation Mechanism

Warm moist air rises from the surface creating a low-pressure area; air spirals inward, rises at the center, and a rotating vortex (hurricane) develops.

Nomenclature

Atlantic and NE Pacific storms are called hurricanes; NW Pacific storms are called typhoons.

El Niño

Warming phase of the equatorial Pacific that affects global climate for about a year or more, altering weather patterns.

La Niña

Cooling phase of the equatorial Pacific, with climate effects opposite to El Niño.

Climate Change

Long-term change in average climate conditions, driven by natural variability and human activities, leading to more extremes such as stronger storms and higher sea levels.

Global Warming

Long-term increase in Earth’s average surface temperature, including ocean warming, contributing to overall climate change.

Greenhouse Gases

Gases such as CO₂, methane, and water vapor that trap heat in the atmosphere; released by burning fossil fuels in heating, electricity, transportation, industry, and agriculture.

Greenhouse Effect

Natural process where greenhouse gases trap heat in the atmosphere, warming the planet; without it Earth would be too cold for life.

Glaciers

Roughly three-quarters of Earth’s freshwater storage; shrinking due to warming; melting contributes to sea level rise and can affect ecosystems.

Ice Sheets

Large land-based ice masses (e.g., Antarctica, Greenland) whose melting raises sea levels.

Sea Ice

Frozen seawater in polar regions; melting affects ecosystems and ocean albedo; does not significantly raise sea level when it melts.

Sea Level Rise

Global increase in ocean height due to melting land ice and thermal expansion; about 7 inches in the last century; projected to rise several feet by 2100.

Ocean Temperatures and Hurricanes

Warmer sea surface temperatures increase evaporation and atmospheric moisture, fueling stronger hurricanes.

Heavy Rainfall and Flooding

Warmer air holds more moisture, leading to heavier rainfall and greater flood risk during storms.

Heatwaves

Extended periods of extreme heat that cause high mortality; example: Europe, 2003.

Climate vs Weather

Weather is short-term atmospheric conditions; climate is the long-term average pattern; extremes can occur without changing climate, but persistent extremes can shift the climate average.

Climate Refugees

People displaced by climate-related disasters and changing environmental conditions.

Mosquitoes (Disease Vectors)

Climate change can expand the range and seasonality of mosquitoes, increasing risks of vector-borne diseases.